DE112022008050T5 - Bicycle gears - Google Patents

Abstract

The disclosure relates to a bicycle transmission comprising a transmission input and a transmission output, each associated with a first axis and a second axis offset from the first axis. The bicycle transmission comprises a first transmission providing a first gear stage between a first transmission input associated with the first axis and a first transmission output associated with the second axis. The bicycle transmission further comprises a second transmission providing a second gear stage between a second transmission input associated with the second axis and a second transmission output associated with the first axis. The bicycle transmission further comprises a third planetary gear and/or a fourth continuously variable transmission between the first transmission and the second transmission.

Description

AREA

The invention relates to a transmission for a bicycle

GENERAL STATE OF THE ART

Bicycles typically include a transmission selectively operable according to a plurality of gear ratios. Bicycle hub gears are known, in which a gear-shifting mechanism is housed in the wheel hub of a driven wheel of the bicycle. Bicycle crank gears are also known, in which a gear-shifting mechanism is housed in a housing on or near the crank of the bicycle. Some bicycles may include an electric drive motor. An output torque of the electric drive motor, which may be relatively substantial, may in some cases be transmitted through the bicycle transmission, thereby increasing the overall load on the bicycle transmission.

SUMMARY

A general goal is to provide a robust and mechanically efficient bicycle transmission that is lightweight and can be manufactured at minimal cost. It is also a goal to provide a bicycle transmission capable of shifting gears under load, preferably in an energy-efficient manner.

According to one aspect, a bicycle transmission is provided that includes a transmission input and a transmission output, each associated with a first axis and a second axis offset from the first axis. The bicycle transmission includes a first transmission providing a first gear ratio between a first transmission input associated with the first axis and a first transmission output associated with the second axis. The bicycle transmission also includes a second transmission providing a second gear ratio between a second transmission input associated with the second axis and a second transmission output associated with the first axis. The bicycle transmission further includes a third planetary transmission and/or a fourth continuously variable transmission. The third planetary transmission and/or the fourth continuously variable transmission is operatively disposed between the first transmission and the second transmission. The third planetary transmission provides a third gear ratio between a third transmission input associated with the second axis and a third transmission output associated with the second axis, wherein the third planetary transmission is configured to provide the third gear ratio to selectively have one of a plurality of different third gear ratios. The fourth continuously variable transmission provides a fourth gear stage between a fourth transmission input associated with the second axle and a fourth transmission output associated with the second axle. Thus, at least three transmissions are connected in series, i.e., at least the first transmission and the second transmission, and also the third planetary transmission and/or the fourth continuously variable transmission, providing a wide range of achievable system gear ratios for the bicycle transmission. By having the third planetary transmission and/or the fourth continuously variable transmission associated with the second axle in a transmission path downstream of the first transmission, mechanical loads on the third planetary transmission and/or the fourth continuously variable transmission can be minimized. This can improve the robustness and overall efficiency of the bicycle transmission.

It is understood that the bicycle transmission may comprise either the third planetary gear or the fourth continuously variable transmission, or both the third planetary gear and the fourth continuously variable transmission. If the bicycle transmission comprises the third planetary gear, it is associated with the second axis and arranged in series between the first gear and the second gear. Likewise, if the bicycle transmission comprises the fourth continuously variable transmission, it is associated with the second axis and arranged in series between the first gear and the second gear. If the bicycle transmission comprises both the third planetary gear and the fourth continuously variable transmission, the third planetary gear and the fourth continuously variable transmission may be arranged in series with each other. Advantageously, the fourth continuously variable transmission may be arranged on an input side of the third planetary gear, i.e., in a transmission path between the first gear and the fourth continuously variable transmission.

According to another aspect, a bicycle transmission is provided that includes a transmission input associated with a first axle and a transmission output associated with a second axle offset from the first axle. The transmission further includes a first gearing providing a first gear stage between a first transmission input associated with the first axle and a first transmission output associated with the second axle. The bicycle transmission further includes a third planetary gearing and/or a fourth continuously variable transmission. The third planetary gearing and/or the fourth continuously variable transmission are arranged in series with the first transmission. The third planetary gearing provides a third gear stage between a third transmission input associated with one of the first axle or the second axle and a third transmission output associated with the same from the first axle or the second axle, wherein the third planetary gearing is configured to provide the third gear stage to selectively have one of a plurality of different third gear ratios. The fourth continuously variable transmission provides a fourth gear ratio between a fourth transmission input associated with one of the first axle or the second axle and a fourth transmission output associated with the same from the first axle or the second axle.

The following may apply to any of the aspects described in this document.

The bicycle transmission may include a first wheel axle extending along the first axis and a second wheel axle extending along the second axis. Each wheel axle may include a plurality of wheel axle portions that may be rotatable relative to one another. For example, the first wheel axle may include an input wheel axle portion that is rotatable about the first axis and forms the transmission input. The first wheel axle may also include, for example, an output wheel axle portion that is rotatable about the first axis relative to the input wheel axle portion and forms the transmission output. The bicycle transmission may also include a second wheel axle extending along the second axis. The second wheel axle may include a plurality of wheel axle portions. The second wheel axle may thus be offset from the first wheel axle. The second wheel axle may be considered a skip wheel axle or an intermediate wheel axle of the bicycle transmission. In one example, at least a portion of the second wheel axle may be held stationary, e.g., relative to a transmission housing.

Optionally, the third planetary gear train comprises three rotating elements, a third of the rotating elements being non-rotatably attached to a stationary part. The three rotating elements may include a ring gear, a planet carrier carrying one or more planet gears, and a sun gear. One of these rotating elements, namely the third of the rotating elements, may be held stationary, e.g., by non-rotatably mounting the third of the rotating elements to the stationary part of the bicycle or bicycle transmission. The stationary part may, for example, be a gear housing of the bicycle transmission or a stationary wheel axle of the bicycle transmission. A first and a second of the rotating elements may be used, e.g., selectively, as an input or output of the third planetary gear train.

Optionally, the third of the rotating elements includes or is a sun gear. The sun gear may, for example, be non-rotatably mounted on a stationary second wheel axle extending along the second axis. The stationary second wheel axle may, for example, be non-rotatably mounted on a gear housing of the bicycle transmission.

The planetary gear set of the third planetary gear unit may be a sun-gearless planetary gear set with only one planet carrier carrying one or more planet gears and two ring gears. If necessary, only one planet carrier is rotatably mounted on the stationary part.

The planetary gear set of the third planetary gear unit may be a ring-gearless planetary gear set with only one planet carrier carrying one or more planet gears and two sun gears. In some cases, only one planet carrier is rotatably mounted on the stationary part.

Optionally, the one or more planetary gears of the third planetary gear set are stepped planetary gears, comprising a large-radius gear part and a small-radius gear part that are rotatably attached to each other. This makes it possible to achieve a relatively large gear ratio with a relatively compact design.

If necessary, the stepped planetary gear comprises two, e.g. identical, small-radius gear parts that are rotatably mounted on the large-radius gear part on opposite sides of the large-radius gear part. A symmetrical planetary gear can thus be obtained, which ensures effective Support for the stepped planetary gear is enabled. The large-radius gear part can mesh with the ring gear, for example, so that torque can be delivered from the planet carrier via the large-radius planetary gear part to the ring gear, with the two small-radius planetary gear parts on opposite sides of the large-radius planetary gear part meshing, for example, with respective sun gear parts of the single-diameter sun gear. A robust yet compact design can thus be achieved.

Optionally, the third planetary gear train comprises a third actuatable clutch and/or a fourth actuatable clutch; wherein the third actuatable clutch is arranged in a transmission path between the input of the third planetary gear train and a first of the rotational elements, and a first freewheel is arranged in a transmission path between the input of the third planetary gear train and a second of the rotational elements, and the fourth actuatable clutch is arranged in a transmission path between the second of the rotational elements and the output of the third planetary gear train, and a second freewheel is arranged in a transmission path between the first of the rotational elements and the output of the third planetary gear train.

The third actuatable clutch may be configured to be selectively in a closed state or an open state. The third actuatable clutch in the closed state is configured to deliver torque through the third actuatable clutch from the input of the third planetary gear set to the first of the rotating elements. The first one-way clutch may be exceeded when the third actuatable clutch is in the closed state. The third actuatable clutch in the open state is configured not to deliver torque therethrough. Instead, the first one-way clutch may deliver torque from the input of the planetary gear set to the second of the rotating elements when the third actuatable clutch is in the open state.

The fourth actuatable clutch may be configured to be selectively in a closed state or an open state. The fourth actuatable clutch in the closed state is configured to deliver torque from the second of the rotating elements through the fourth actuatable clutch to the output of the planetary gear set. The second one-way clutch is exceeded when the fourth actuatable clutch is in the closed state. The fourth actuatable clutch in the open state is configured not to deliver torque therethrough. Instead, the second one-way clutch may deliver torque from the first of the rotating elements to the output of the planetary gear set.

The bicycle transmission can shift between two different gear ratios using one actuatable clutch, e.g., only the third actuatable clutch or only the fourth actuatable clutch. The bicycle transmission can shift between three different gear ratios using two actuatable clutches, e.g., the third actuatable clutch and the fourth clutch module.

With the third actuatable clutch or the fourth actuatable clutch, the third planetary gear set is selectively operable according to two different gear ratios. With the third actuatable clutch and the fourth actuatable clutch, the third planetary gear set is selectively operable according to three different gear ratios. The third actuatable clutch and the fourth actuatable clutch can be switched between their respective states, e.g., by actuation, e.g., electrically. In particular, the third actuatable clutch and the fourth actuatable clutch can be actuated independently of one another.

The first freewheel and the second freewheel can be passive mechanisms that are not actuated. A freewheel is overridden when its output rotates faster than its input; for example, each freewheel is configured to disengage its drive input from its driven output when its driven output rotates faster than its drive input.

Optionally, the first of the rotating elements is a planet carrier carrying one or more planet gears. Optionally, the second of the rotating elements is a ring gear. Optionally, the third of the rotating elements is a sun gear. The third actuatable clutch can thus be used to selectively deliver torque from the input of the third planetary gear set to the planet carrier or the ring gear. The fourth actuatable clutch can be used to selectively deliver torque from the planet carrier or the ring gear to the output of the third planetary gear set.

The third planetary gear set can have a maximum of three rotating elements. One of the rotating elements can be attached to the stationary part, e.g., a stationary wheel axle or a transmission housing. The third actuatable clutch can thus selectively couple the input of the third planetary gear set to one of the unattached rotating elements. Likewise, the second actuatable clutch can selectively couple the output of the third planetary gear set to one of the unattached rotating elements.

The maximum three rotating elements can include a sun gear, a planet carrier carrying one or more planet gears, and a ring gear. The maximum three rotating elements can include a sun gear with a diameter, a planet carrier carrying one or more planet gears, and a ring gear with a diameter. The maximum three rotating elements can include only one sun gear, only one planet carrier carrying one or more planet gears, and only one ring gear. Alternatively, the maximum three rotating elements can include two sun gears and a planet carrier carrying one or more planet gears. Alternatively, the maximum three rotating elements can include two ring gears and a planet carrier carrying one or more planet gears.

The transmission system including the third actuatable clutch and the fourth actuatable clutch specifically enables switching from one gear ratio directly to any other gear ratio in one stage, i.e., without having to pass through an intermediate system gear ratio. For example, the third planetary gear set may be operable according to a first gear ratio, a second gear ratio, and a third gear ratio using the third and fourth actuatable clutches, respectively. The third planetary gear set may shift directly between any of the three gear ratios, e.g., directly from the first to the second and vice versa, directly from the first to the third and vice versa, and directly from the second to the third and vice versa.

Optionally, the third actuatable clutch and the fourth actuatable clutch are positive clutches configured to deliver torque in two rotational directions. In general, any actuatable clutch described in this document may form a positive clutch configured to deliver torque in two rotational directions.

Optionally, each of the third actuatable clutch and the fourth actuatable clutch is configured to be coupled and uncoupled under load. In general, any actuatable clutch described in this document may be configured to be coupled and uncoupled under load.

Optionally, the bicycle transmission comprises a third electrical actuator configured to actuate the third actuatable clutch and a fourth electrical actuator configured to actuate the fourth actuatable clutch. In general, each actuatable clutch described in this document may have a respective electrical actuator associated therewith for electrically actuating the clutch.

Optionally, the third actuatable clutch and the fourth actuatable clutch are independently actuatable. In general, each actuatable clutch described in this document can be independently actuatable from any other actuatable clutch of the bicycle transmission.

If appropriate, the third actuatable clutch is identical to the fourth actuatable clutch. Thus, the bicycle may include at least two identical actuatable clutches connected in series between the transmission input and the transmission output.

Where appropriate, the third actuatable clutch and/or the fourth actuatable clutch are assigned to the second axle.

Optionally, the third planetary gear set is selectively operable according to a uniform gear ratio. Optionally, if the third planetary gear set includes the third actuatable clutch and the fourth actuatable clutch, the third planetary gear set operates according to the uniform gear ratio when the third actuatable clutch is closed and the fourth actuatable clutch is open and/or when the third actuatable clutch is open and the fourth actuatable clutch is closed. Optionally, if the planetary gear set includes the third actuatable clutch and not the fourth actuatable clutch, the planetary gear set operates according to the uniform gear ratio gear ratio when the third actuatable clutch is closed, and according to a non-uniform gear ratio when the third actuatable clutch is open, or vice versa. Where appropriate, if the planetary gear train includes the fourth actuatable clutch and not the fourth actuatable clutch, the planetary gear train operates according to the uniform gear ratio when the fourth actuatable clutch is open, and according to a non-uniform gear ratio when the fourth actuatable clutch is closed, or vice versa.

Optionally, the planetary gear set is selectively operable according to a speed-increasing gear ratio. Optionally, if the third planetary gear set includes the third actuatable clutch and the fourth actuatable clutch, the third planetary gear set operates according to the speed-increasing gear ratio when the third actuatable clutch is closed and the fourth actuatable clutch is closed. Optionally, if the third planetary gear set includes the third actuatable clutch and not the fourth actuatable clutch, the third planetary gear set operates according to the speed-increasing gear ratio when the third actuatable clutch is open.

Optionally, the third planetary gear set is selectively operable according to a speed-reducing gear ratio. Optionally, the speed-increasing gear ratio and the speed-reducing gear ratio of the third planetary gear set are inverse to each other. Optionally, when the third planetary gear set includes the third actuatable clutch and the fourth actuatable clutch, the third planetary gear set operates according to the speed-reducing gear ratio when the third actuatable clutch is open and the fourth actuatable clutch is open. Optionally, when the planetary gear set includes the fourth actuatable clutch and not the third actuatable clutch, the third planetary gear set operates according to the speed-increasing gear ratio when the fourth actuatable clutch is open.

• eine erste Einheit, die mit dem Kupplungseingang verbindbar ist und mindestens eine erste Auflagefläche beinhaltet;
• eine zweite Einheit, die mit dem Kupplungsausgang verbindbar ist und mindestens eine zweite Auflagefläche beinhaltet, die zum selektiven Ineingriffnehmen der ersten Auflagefläche ausgelegt ist, wobei die erste und die zweite Auflagefläche aneinander angepasst sind, um ein Lösen unter Belastung zu ermöglichen, vorzugsweise in zwei Richtungen;
• eine dritte Einheit, die mindestens ein Halteelement beinhaltet, wobei die dritte Einheit derart angeordnet ist, dass sie sich selektiv in einem ersten Modus oder einem zweiten Modus relativ zu der zweiten Einheit befindet, wobei das mindestens eine Halteelement in dem ersten Modus die mindestens eine zweite Auflagefläche verriegelt, um die zweite Einheit rotierend mit der ersten Einheit zu koppeln, z. B. in zwei Richtungen, und in dem zweiten Modus die mindestens eine zweite Auflagefläche freigibt, um die zweite Einheit von der ersten Einheit zu entkoppeln. Das Fahrradgetriebe, das eine derartige betätigbare Kupplung (oder derartige betätigbare Kupplungen) beinhaltet, kann in einem kleinen Formfaktor hergestellt werden, der für die Integration in ein zweirädriges Fahrrad geeignet ist.

For any of the actuatable clutches described in this document, the actuatable clutch may have a clutch input and a clutch output, the actuatable clutch including:

• a first unit connectable to the clutch input and including at least a first bearing surface;
• a second unit connectable to the clutch output and including at least a second bearing surface configured to selectively engage the first bearing surface, the first and second bearing surfaces being adapted to each other to enable release under load, preferably in two directions;
• a third unit including at least one retaining element, the third unit being arranged to be selectively in a first mode or a second mode relative to the second unit, the at least one retaining element locking the at least one second bearing surface in the first mode to rotationally couple the second unit to the first unit, e.g., in two directions, and releasing the at least one second bearing surface in the second mode to decouple the second unit from the first unit. The bicycle transmission incorporating such an actuatable clutch (or such actuatable clutches) can be manufactured in a small form factor suitable for integration into a two-wheeled bicycle.

Optionally, the actuatable clutch includes an actuator for moving the third unit from a first position to a second position or from a second position to a first position relative to the second rotatable unit.

Optionally, the third unit includes at least one actuating element configured to move the third unit from a first position to a second position or from a second position to a first position relative to the second rotatable unit.

Optionally, the actuatable clutch further includes a fourth unit including a selection unit, the selection unit being configured to be selectively in a gripping or non-gripping mode,
wherein the selection unit is configured in the gripping mode to grip the at least one actuating element for rotating the third rotatable unit from the first position to the second position or from the second position to the first position relative to the second rotatable unit;
wherein the selection unit is designed to release the at least one actuating element in the non-gripping mode.

Optionally, the actuatable clutch includes a first rotatable unit connectable to the input; a second rotatable unit connectable to the output; a third rotatable unit configured to rotate together with the second rotatable unit, wherein the third rotatable unit is configured to be selectively located in a first rotational position or a second rotational position relative to the second rotatable unit, wherein the actuatable clutch is configured to be selectively located in the first rotational position in which the second rotatable unit is rotationally coupled to the first rotatable unit and in the second rotational position in which the second rotatable unit is uncoupled from the first rotatable unit; wherein the actuatable clutch is configured to temporarily change the rotational speed of the third rotatable unit relative to the second rotatable unit to rotate from the first position to the second position or from the second position to the first position.

Optionally, the actuatable clutch module further comprises a fourth unit including a selection unit, wherein the selection unit is configured to be selectively in a gripping mode or a non-gripping mode; wherein the selection unit is configured in the gripping mode to grip the at least one actuating element for rotating the third rotatable unit from the first position to the second position or from the second position to the first position relative to the second rotatable unit; wherein the selection unit is configured in the non-gripping mode to release the at least one actuating element.

Optionally, any one or more of the first unit, the second unit, the third unit, and the fourth unit of the actuatable clutch are associated with the second axis. For example, the first unit, the second unit, the third unit, and/or the fourth unit of the actuatable clutch may be rotatable about the second axis.

For example, any actuatable clutch described in this document may be similar or identical to a clutch described in WO2018/199757A2 , WO2020/085911A2 or WO2021/080431A1 described.

Optionally, the first gear stage is formed by a cooperating gear pair with a primary gear rotatable about the first axis and a secondary gear rotatable about the second axis.

Optionally, the first transmission for providing the first gear stage is configured to selectively have one of a plurality of different first gear ratios. For example, the first transmission may include a plurality of cooperating gear pairs, with torque being selectively delivered by any one of the cooperating gear pairs.

Optionally, the first transmission includes a first actuatable clutch for shifting the first transmission from one of the plurality of first gear ratios to another and/or vice versa.

Optionally, the first actuatable clutch is identical to the third actuatable clutch and/or the fourth actuatable clutch. Thus, the bicycle transmission may include at least three identical actuatable clutches arranged in series between the transmission input and the transmission output.

If appropriate, the first actuatable clutch is assigned to the second axle. Coupling elements of the first actuatable clutch can, for example, be rotatable about the second axle or be coupled or capable of being coupled to the second wheel axle.

Where appropriate, each of the first, third and fourth actuatable clutches is assigned to the second axle.

Optionally, the first gear stage is formed selectively by a first cooperating gear pair arranged in a first transmission path or a second cooperating gear pair arranged in a second transmission path parallel to the first transmission path. wherein each of the first and second cooperating gear pairs includes a primary gear rotatable about the first axis and a secondary gear rotatable about the second axis, wherein the first actuatable clutch is configured to selectively enable torque transmission through any one of the first transmission path or the second transmission path from the first transmission input to the first transmission output.

Optionally, the first actuatable clutch is arranged in the first transmission path, which is connected in series with the first cooperating gear pair, and a fifth one-way clutch is arranged in the second transmission path, which is connected in series with the second cooperating gear pair, or vice versa. The first actuatable clutch can be selectively in a closed state or an open state. The first actuatable clutch in the closed state is configured to deliver torque therethrough to deliver torque through the first transmission path, i.e., via the first cooperating gear pair, from the first transmission input to the first transmission output. The fifth one-way clutch can be exceeded when the first actuatable clutch is in the closed state. The first actuatable clutch in the open state is configured not to deliver torque therethrough to deliver torque through the second transmission path, i.e., via the fifth one-way clutch and the second cooperating gear pair, from the first transmission input to the first transmission output.

Optionally, the primary gear and the secondary gear of each of the first and/or second cooperating gear pairs mesh with each other. Alternatively, the primary gear and the secondary gear of each of the first and/or second cooperating gear pairs may not mesh with each other, such as via a respective endless drive element, e.g., a chain or belt.

Optionally, the second gear stage is formed by a cooperating gear pair with a primary gear rotatable about the second axis and a secondary gear rotatable about the first axis.

Optionally, the second transmission for providing the second gear stage is configured to selectively have one of a plurality of different second gear ratios.

Optionally, the second transmission includes a second actuatable clutch for shifting the second transmission from one of the plurality of second gear ratios to another and/or vice versa.

Optionally, the second actuatable clutch is identical to the third actuatable clutch and/or the fourth actuatable clutch. The first, second, third, and fourth actuatable clutches can thus be identical to one another, thereby providing the advantage of production scalability. Thus, the bicycle transmission can include at least four identical actuatable clutches connected in series between the transmission input and the transmission output.

If appropriate, the second actuatable clutch is assigned to the second axle. Coupling elements of the second actuatable clutch can, for example, be rotatable about the second axis or be coupled or capable of being coupled to the second wheel axle.

Optionally, each of the first, second, third, and fourth actuatable clutches is assigned to the second axle. In particular, each actuatable clutch of the bicycle transmission can be assigned to the second axle, for example. The first axle can thus be free of actuatable clutches.

Optionally, the second gear stage is selectively formed by a third cooperating gear pair arranged in a third transmission path or a fourth cooperating gear pair arranged in a fourth transmission path parallel to the third transmission path, each of the third and fourth cooperating gear pairs comprising a primary gear rotatable about the second axis and a secondary gear rotatable about the first axis, the second actuatable clutch being configured to selectively enable torque transmission through any one of the third transmission path or the fourth transmission path from the second transmission input to the second transmission output.

Optionally, the second actuatable clutch is arranged in the third transmission path connected in series with the third cooperating gear pair, and a one-way clutch is arranged in the fourth transmission path connected in series with the fourth cooperating gear pair, or vice versa. The second actuatable clutch can be selectively in a closed state or an open state. The second actuatable clutch in the closed state is configured to deliver torque therethrough to deliver torque through the third transmission path, i.e., via the third cooperating gear pair, from the second transmission input to the second transmission output. The one-way clutch can be exceeded when the second actuatable clutch is in the closed state. The second actuatable clutch in the open state is configured not to deliver torque therethrough to deliver torque through the fourth transmission path, i.e., via the one-way clutch and the fourth cooperating gear pair, from the second transmission input to the second transmission output.

Optionally, the primary gear and the secondary gear of each of the first and/or second cooperating gear pairs are non-meshing with each other, such as via a respective endless drive element, e.g., a chain or belt.

If applicable, the fourth continuously variable transmission (CVT)
a first input member rotatable about a first CVT axis; a second input member rotatable about a second CVT axis, the first input member being movable relative to the second input member in a direction transverse to the first CVT axis and the second CVT axis; coupling elements provided at a constant first radius from the first CVT axis and a variable second radius from the second CVT axis, or at a constant first radius from the second CVT axis and a variable second radius from the first CVT axis, for delivering torque between the first input member and the second input member. The first input member and the second input member are movable relative to each other in a direction transverse to the first CVT axis and the second CVT axis for delivering torque at different gear ratios. By varying the relative displacement between the first input member associated with the first CVT axle and the second input member associated with the second CVT axle, the variable second radius in which torque is delivered between the input and second input member is varied.

Therefore, different gear ratios can be achieved between the first drive element and the second drive element. The CVT can be implemented in a relatively small form factor with relatively few components and low mass.

Optionally, the coupling elements are coupled to the second drive element in a tangential direction and movable relative to the second drive element in a radial direction, wherein the coupling elements are coupled to the first drive element in a radial direction in the first radius from the first CVT axis and movable relative to the first drive element in a first tangential direction, and wherein the coupling elements are coupled to the first drive element in a second tangential direction, which is opposite to the first tangential direction. Thus, the coupling elements can be held at a predetermined radial distance relative to the first CVT axis. The coupling elements can, for example, be freely movable relative to the first drive element in the first tangential direction and coupled to the first drive element in the second tangential direction relative to the first drive element. Therefore, the first drive element can drive the coupling elements in rotation in the first tangential direction, and the first drive element can move freely relative to the coupling elements in the second tangential direction. Furthermore, the coupling elements can drive the first drive element in rotation in the second tangential direction, and the coupling elements can move freely relative to the first drive element in the first tangential direction.

Optionally, the second CVT axis coincides with the second axis and wherein the first drive member is movable relative to the second drive member into an eccentric position offset from the second axis.

Optionally, the first drive element is pivotally movable about a pivot axis extending parallel to the first CVT axis for pivotally moving relative to the second drive element in a direction transverse to the first CVT axis.

Optionally, the first drive element comprises a first concentric guide extending concentrically around the first CVT axis, wherein the first concentric guide is configured to guide movement of the coupling elements in the first tangential direction. The first concentric guide may, for example, be a slot provided in the first drive element, wherein the slot extends concentrically around the first CVT axis.

Optionally, the first concentric guide and the coupling elements form or include a one-way coupling for enabling movement of the coupling elements relative to the first concentric guide in the first tangential direction and for blocking movement of the coupling elements relative to the first concentric guide in the second tangential direction. The one-way coupling may, for example, be a keying or ratchet coupling. Each of the coupling elements may, for example, comprise a one-way unit configured to be keyed between an inner ring and an outer ring of the first concentric guide when driven in the second tangential direction.

Optionally, each of the coupling elements comprises a wedging body that can be tilted about a tilting axis between a neutral position, in which free movement of the coupling element relative to the first concentric guide is possible, and a wedged position, in which the wedging body is wedged into engagement with the first concentric guide. For example, the wedging body can be wedged between two rings of the first concentric guide, e.g., between an inner ring and an outer ring. It is understood that the neutral position and the wedged position can differ only slightly, e.g., a few micrometers at the extreme points. To assume the neutral position, it is sufficient for the wedging body to no longer be wedged into engagement with the first concentric guide.

Optionally, each of the coupling elements comprises at least one roller for activating the tilting of the wedging body from the neutral position to the wedged position.

Optionally, a first end of the wedging body is provided with a converging wedging recess for engaging a first roller, and a second end of the wedging body, opposite the first end, is provided with a diverging wedging recess for engaging a second roller. Here, converging and diverging are defined as viewed in a direction away from the center of the wedging body. With respect to a free-running direction of the wedging bodies, the converging wedging recess may be provided at a front end of the wedging bodies, and the diverging recess may be provided at a rear end of the wedging bodies. The first roller may, for example, be provided between an inner ring of the first concentric guide and a converging wedging surface of the converging wedging recess. The second roller may, for example, be provided between an outer ring of the first concentric guide and a diverging wedging surface of the diverging wedging recess. Optionally, the first and/or second rollers are preloaded in a wedging direction, e.g., elastically, e.g., with a spring. The first and/or second rollers can be preloaded toward the converging side of the wedging recesses. This provides the advantage that the wedging body is preloaded in a wedged state and can be released by movement in the freewheeling direction.

Optionally, the second drive element comprises first radial guides extending at least radially with respect to the second CVT axis, i.e., having a radial component. The first radial guides are designed to guide the movement of the coupling elements in the radial direction and to transmit torque in the tangential direction. The first radial guides may comprise radially extending slots in a body of the second drive element.

Optionally, each of the coupling elements comprises a guide wheel for running along the first radial guides.

Optionally, the coupling elements are movably connected, such as articulated, to the second drive element to enable radial movement of the coupling elements relative to the second drive element.

Optionally, each wedging body is pivotable about a tilting axis between a neutral position allowing free movement of the coupling element relative to the first concentric guide and a wedged position in which each wedging body is in wedging engagement with the first concentric guide, tiltable.

Optionally, each of the coupling elements comprises two wedging bodies. Optionally, each wedging body of the first coupling element is tiltable about a common tilt axis between a neutral position, in which free movement of the coupling element relative to the first concentric guide is possible, and a wedged position, in which each wedging body is wedged into engagement with the first concentric guide.

If necessary, the guide wheel can be rotated around the common tilting axis, with the two wedging bodies arranged on both sides of the guide wheel.

Optionally, the transmission is designed to pivot the first drive element about the pivot axis between a first extreme position and a second extreme position, e.g. between a concentric position in which the first CVT axis coincides with the second CVT axis and an eccentric position in which the first CVT axis is offset from the second CVT axis.

Optionally, the first drive element is pivotable about the pivot axis into a selective position within a continuous pivot range defined between the first extreme position and the second extreme position, e.g., between the concentric position and the eccentric position, the continuous pivot range being symmetrical with respect to a horizontal plane through the pivot axis.

Where appropriate, the first drive element of the CVT is attached to or integrated into the secondary gear of the first transmission stage.

The primary gear and the secondary gear of the first gear stage may not mesh with each other, such as through an endless drive element. This facilitates the movement of the first drive element relative to the second drive element.

Optionally, the fourth continuously variable transmission comprises a third input element rotatable about a third axis parallel to the second axis. The third input element and the second input element may be movable relative to each other in a direction transverse to the third and second axes. The CVT may include second coupling elements provided at a constant third radius from the third axis and at a variable fourth radius from the second axis for delivering torque between the third input element and the second input element. Thus, torque may be transmitted from the first input element to the second input element according to a first CVT gear ratio and from the second input element to the third input element according to a second CVT gear ratio. In particular, the first and second CVT gear ratios are arranged in series, and thus a gear ratio step of the CVT unit obtainable with the CVT unit can be increased. Optionally, the constant first radius corresponds to the constant third radius, i.e., the constant first radius and the constant third radius are equal. Where appropriate, the variable second radius corresponds to the variable fourth radius, i.e. the variable second radius and the variable fourth radius are equal.

Optionally, the second coupling elements are coupled to the second drive element in a tangential direction and movable relative to the second drive element in a radial direction. Thus, the second coupling elements can move radially relative to the second axis while remaining tangentially coupled to the second third drive element. Optionally, the second coupling elements are coupled to the third drive element in a radial direction at the constant third radius and movable relative to the third drive element in a fourth tangential direction. Optionally, the second coupling elements can be coupled to the third drive element in a third tangential direction that is opposite to the fourth tangential direction. Optionally, the third tangential direction corresponds to the first tangential direction, i.e., the third and first tangential directions are the same. Optionally, the fourth tangential direction corresponds to the second tangential direction, i.e., the fourth and second tangential directions are the same. Thus, the second coupling elements can be coupled to the third drive element in a radial direction in the third radius and can be moved relative to the third drive element in the second tangential direction, and the second coupling elements can be coupled to the third drive element in the first tangential direction. Therefore, the second coupling elements can drive the third drive element in rotation in the first tangential direction and can the second coupling elements move freely in the second tangential direction relative to the third drive element. Furthermore, the third drive element can drive the second coupling elements in rotation in the second tangential direction, and the third drive element can move freely in the first tangential direction relative to the second coupling elements.

Optionally, the third drive element comprises a second concentric guide extending concentrically around the third axis, wherein the second concentric guide is configured to guide movement of the second coupling elements in the third tangential direction. The second concentric guide may, for example, be a slot provided in the third drive element, wherein the slot extends concentrically around the third axis.

Optionally, the second concentric guide and the second coupling elements form or include a one-way coupling for enabling movement of the second coupling elements relative to the second concentric guide in the fourth tangential direction and for blocking movement of the second coupling elements relative to the second concentric guide in the third tangential direction.

Optionally, each of the second coupling elements comprises a wedging body that can be tilted about a tilting axis between a neutral position, in which free movement of the coupling element relative to the first concentric guide is enabled, and a wedged position, in which the wedging body is wedged into engagement with the second concentric guide. For example, the wedging body can be wedged between two rings of the second concentric guide, e.g., between an inner ring and an outer ring. It is understood that the neutral position and the wedged position can differ only slightly, e.g., a few micrometers at the extreme points. To assume the neutral position, it is sufficient for the wedging body to no longer be wedged into engagement with the first concentric guide.

Optionally, each of the second coupling elements comprises at least one roller for activating the tilting of the wedging body from the neutral position to the wedged position.

Optionally, a first end of the wedging body is provided with a converging wedging recess for cooperating with a first roller, and a second end of the wedging body, opposite the first end, is provided with a diverging wedging recess for cooperating with a second roller. With respect to a freewheeling direction of the wedging bodies, the converging wedging recess can be provided at a front end of the wedging bodies, and the diverging recess can be provided at a rear end of the wedging bodies. The first roller can, for example, be provided between an inner ring of the second concentric guide and a converging wedging surface of the converging wedging recess. The second roller can, for example, be provided between an outer ring of the second concentric guide and a diverging wedging surface of the diverging wedging recess. Optionally, the first and/or the second roller are preloaded in a wedging direction, e.g. B. elastically, e.g. with a spring. The first and/or second roller can be preloaded toward the converging side of the wedging recesses. This provides the advantage that the wedging body is preloaded in a wedged state and can be released by movement in the freewheeling direction.

Optionally, the second drive element comprises second radial guides extending radially relative to the second axis, wherein the second radial guides are configured to guide the movement of the second coupling elements in a radial direction and to transmit torque in a tangential direction. The second radial guides may comprise radially extending slots in a body of the second drive element.

Optionally, each of the second coupling elements comprises a guide wheel for running along the second radial guides.

Optionally, the second coupling elements are movably connected, such as articulated, to the second drive element to enable radial movement of the second coupling elements relative to the second drive element.

Optionally, each wedging body is tiltable about a tilting axis between a neutral position in which free movement of the coupling element relative to the second concentric guide is possible and a wedged position in which each wedging body is in wedging engagement with the second concentric guide.

Optionally, each of the second coupling elements comprises two wedging bodies. Optionally, each wedging body of the second coupling elements is tiltable about a common tilt axis between a neutral position, in which free movement of the coupling element relative to the second concentric guide is possible, and a wedged position, in which each wedging body is in wedging engagement with the second concentric guide.

If necessary, the guide wheel can be rotated around the common tilting axis, with the two wedging bodies arranged on both sides of the guide wheel.

If necessary, the first axis and the third axis coincide. For example, the first drive element and the third drive element can be rotatable about a common axis.

Optionally, the second drive element is pivotally movable about a pivot axis extending parallel to the first and second axes for pivotal movement relative to the first drive element in a direction transverse to the first and second axes. Thus, the second drive element can be moved relative to the first drive element about the pivot axis by a rotational drive.

Optionally, the fourth continuously variable transmission comprises a second gear concentrically coupled to the second input member and rotatable therewith about the second axis; and a first gear driveably connected to the second gear for transmitting torque between the first and second gears, the first gear having a rotational axis coincident with the pivot axis. For example, the first gear and the second gear may be a first gear and a second gear, respectively, the first and second gears meshing to provide torque. Alternatively, the first gear and the second gear may be a first chainring and a second chainring, respectively, connected by a chain.

Optionally, the fourth continuously variable transmission comprises an endless drive element, e.g., a chain or belt, which driveably engages the first gear wheel and the second gear wheel to transmit torque between the first and second gear wheels. A gearless transmission can thus be obtained. Furthermore, when the first drive element is driven in rotation about the first axis, drive force is supplied, for example, from the first coupling elements to the second drive element. This force acts on the second drive element in a substantially opposite direction as a reaction force from the endless drive element. Thus, an actuating force for moving the second drive element relative to the first drive element can be reduced, at least with respect to a pinion arrangement.

Optionally, the fourth continuously variable transmission is configured to pivot the second drive member between a concentric position in which the first and second axes coincide and an eccentric position in which the first and second axes are offset. When the first drive member drives the second drive member in a driven rotational direction about the second axis, the fourth continuously variable transmission is configured to pivot the second drive member from the concentric position to the eccentric position in a rotational direction about the pivot axis opposite to the driven rotational direction. When the second drive member drives the first drive member in a driven rotational direction about the first axis, the fourth continuously variable transmission is configured to pivot the second drive member from the concentric position to the eccentric position in the driven rotational direction about the pivot axis. Thus, an actuating force for moving the second drive member relative to the first drive member can be minimized.

Optionally, e.g. alternatively or additionally, the first drive element is pivotally movable about a pivot axis extending parallel to the first and second axes for pivotal movement relative to the second drive element in a direction transverse to the first and second axes. Then, the fourth continuously variable transmission can be arranged to pivot the first drive element between a concentric position in which the first and second axes coincide, and an eccentric centric position in which the first and second axes are offset, and wherein, when the second drive element drives the first drive element in a driven rotational direction about the second axis, the fourth continuously variable transmission is configured to pivot the first drive element from the concentric position to the eccentric position in a rotational direction about the pivot axis opposite to the driven rotational direction; and, when the first drive element drives the second drive element in a driven rotational direction about the first axis, the fourth continuously variable transmission is configured to pivot the first drive element from the concentric position to the eccentric position in the driven rotational direction about the pivot axis. Thus, an actuating force for moving the first drive element relative to the second drive element can be minimized.

Optionally, the fourth continuously variable transmission comprises a pivot arm for coupling the first gear to the second gear and defining a constant distance between the second axis and the pivot axis, the pivot arm extending between a first end, at which the pivot arm couples to the first gear at the pivot axis, and a second end, at which the pivot arm couples to the second gear at the second axis. Since the first gear is rotationally associated with the pivot axis and the second gear is associated with the second axis, the first and second gears can be drivably engaged, while the second gear is pivoted together with the second drive element relative to the first gear, e.g., directly meshingly engaged or via an endless drive element such as a belt or chain.

Optionally, the fourth continuously variable transmission comprises a fourth gear concentrically coupled to the second input member and rotatable therewith about the second axis; and a third gear drivably connected to the fourth gear for transmitting torque between the third and fourth gears, the third gear having an axis of rotation coincident with the pivot axis.

If necessary, the fourth continuously variable transmission may be similar to the CVT as described in the also pending patent application PCT/ EP1022/060920 which is incorporated in its entirety by reference.

Optionally, the bicycle transmission comprises a transmission housing that holds the first transmission and the second transmission, and further contains the third planetary transmission and/or the fourth continuously variable transmission. The housing can seal components of the bicycle transmission from the environment. For example, the housing defines a sealed cavity in which the first transmission and the second transmission, and further the third planetary transmission and/or the fourth continuously variable transmission, can be provided.

Optionally, the bicycle transmission comprises an electric drive motor with a motor output axis that coincides with the first axis. Optionally, the bicycle transmission comprises an electric drive motor with a motor output axis that coincides with the second axis.

Where appropriate, the electric drive motor is configured to output a maximum rated power of no more than 10 kW, preferably no more than 4 kW.

If necessary, the electric drive motor is contained in the gearbox housing.

Optionally, the bicycle transmission comprises a crank connected to the transmission input for rotation about the first axis and a chainring connected to the transmission output for rotation about the first axis.

According to one aspect, a twelve-speed bicycle transmission is provided, comprising: a transmission input and a transmission output, each associated with a first axle; a second axle offset from the first axle; a first transmission providing a first gear stage between a first transmission input associated with the first axle and a first transmission output associated with the second axle, wherein the first transmission is configured to provide the first gear stage to selectively have one of two different first gear ratios; a second transmission providing a second gear stage between a second transmission input associated with the second axle and a second transmission output associated with the first axle, wherein the second transmission is configured to provide the second gear stage to selectively have one of two different second gear ratios; and a third planetary gear A transmission providing a third gear stage between a third transmission input associated with the second axle and a third transmission output associated with the second axle, wherein the third planetary gear for providing the third gear stage is configured to selectively have one of three different third gear ratios.

Another aspect provides a bicycle comprising a bicycle transmission as described herein. It is understood that a bicycle includes similar human-powered, particularly pedal-powered, vehicles, such as tricycles, quadricycles, etc. The bicycle transmission may be implemented as a hub gear of the bicycle and/or as a crank gear of the bicycle.

According to one aspect, an electrically powered vehicle is provided, such as a lightweight electrically powered vehicle, for example, an electrically powered bicycle or an electrically powered scooter. The electrically powered vehicle comprises a bicycle transmission as described herein and an electric drive motor with a rated power of no more than 10 kW, preferably no more than 4 kW; wherein the electric drive motor is configured to drive or assist in driving the vehicle, wherein the rated power of the drive motor is transmitted at least partially through the bicycle transmission.

It is understood that any of the aspects, features, and options described in this document may be combined. In particular, it is understood that any of the aspects, features, and options described with respect to the bicycle transmission apply equally to the bicycle and the electrically powered vehicle, and vice versa.

BRIEF DESCRIPTION OF THE DRAWINGS

• 1A und 1B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 2 zeigt ein schematisches Beispiel für ein Fahrradgetriebe;
• 3A und 3B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 4A und 4B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 5A und 5B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 6A und 6B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 7A und 7B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 8A und 8B zeigen ein schematisches Beispiel für ein Fahrradgetriebe;
• 9A und 9B zeigen ein Fahrrad.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which:

• 1A and 1B show a schematic example of a bicycle transmission;
• 2 shows a schematic example of a bicycle transmission;
• 3A and 3B show a schematic example of a bicycle transmission;
• 4A and 4B show a schematic example of a bicycle transmission;
• 5A and 5B show a schematic example of a bicycle transmission;
• 6A and 6B show a schematic example of a bicycle transmission;
• 7A and 7B show a schematic example of a bicycle transmission;
• 8A and 8B show a schematic example of a bicycle transmission;
• 9A and 9B show a bicycle.

DETAILED DESCRIPTION

The 1A and 1B show an example of a bicycle transmission 1000 with a transmission input I and a transmission output O. The bicycle transmission 1000 comprises a first transmission 100 and a second transmission 200, which are connected in series between the transmission input I and the transmission output O. The first transmission 100 provides a first gear stage between a first transmission input 101, which is assigned to a first axis A1, and a first transmission output 102, which is assigned to a second axis A2. The first axis A1 and the second axis A2 are offset from one another. The second transmission 200 provides a second gear stage between a second transmission input 201, which is assigned to the second axis A2, and a second transmission output 202, which is assigned to the first axis A1.

The bicycle transmission 1000 may include a first wheel axle 47 extending along the first axis A1. The first wheel axle 47 may include a plurality of first wheel axle parts that are rotatable relative to one another. Here, the first wheel axle 47 has an input wheel axle part 47A that is rotatable about the first axis A1 and configured to be connected to an input drive element, such as a crank of the bicycle. Here, the first wheel axle 47 has an output wheel axle part 47B that is also rotatable about the first axis A1 and configured to be connected to an output drive element, such as a chainring 19. The bicycle transmission 1000 may also include a second wheel axle 48 extending along the second axis A2. The first wheel axle 47 and the second wheel axle 48 are thus also offset from each other. Here, the stationary wheel axle 48 is a stationary wheel axle that is non-rotatably attached to a housing 49 of the bicycle transmission 1000.

The first transmission 100, in this example, is operable according to two different gear ratios. It is understood that the first transmission 100 can alternatively be operable according to only one gear ratio or according to more than two gear ratios. To shift between the two gear ratios, the first transmission 100 includes a first actuatable clutch C1, in this example a load-shifting clutch. The first transmission 100 here has two parallel transmission paths between the first transmission input 101 and the first transmission output 102, namely a first transmission path 100A and a second transmission path 100B. Here, the first transmission path 100A includes the first actuatable clutch C1. Furthermore, the first transmission path 100A here includes a first cooperating gear pair R1 with a primary gear rotatable about the first axis A1 and a secondary gear rotatable about the second axis A2. In this example, the second transmission path 100B includes a first freewheel V1 and a second cooperating gear pair R2 with a primary gear rotatable about the first axis A1 and a secondary gear rotatable about the second axis A2. Here, each primary gear of the first transmission 100 is mounted on the first wheel axle 47, specifically the input wheel axle portion 47A thereof. The first freewheel V1 is associated with the first axis A1 in this example. Each secondary gear of the first transmission 100 is rotatable about the stationary second wheel axle 48.

The second transmission 200, in this example, is also operable according to two different gear ratios. It is understood that the second transmission 200 can alternatively be operable according to only one gear ratio or according to more than two gear ratios. To shift between the two gear ratios, the second transmission 200 includes a second actuatable clutch C2, in this example a load-shifting clutch. The second transmission 200 here has two parallel transmission paths between the second transmission input 201 and the second transmission output 202, namely a third transmission path 200A and a fourth transmission path 200B. Here, the third transmission path 200A includes the second actuatable clutch C2. Furthermore, the third transmission path 100A here includes a third cooperating gear pair R3 with a primary gear rotatable about the second axis A2 and a secondary gear rotatable about the first axis A1. In this example, the fourth transmission path 200B includes a second freewheel V2 and a fourth cooperating gear pair R4 with a primary gear rotatable about the second axis A2 and a secondary gear rotatable about the first axis A1. Here, each secondary gear of the second transmission 200 is mounted on the first gear axle 47, specifically the output gear axle portion 47B. Each primary gear of the second transmission 200 is rotatable about the stationary second gear axle 48.

The first and second actuatable clutches C1 and C2 can be used to select an appropriate transmission path between the transmission input I and the transmission output O. Specifically, the first actuatable clutch C1 can be used to selectively switch between the first transmission path 100A and the second transmission path 100B of the first transmission 100, and the second actuatable clutch C2 can be used to selectively switch between the third transmission path 200A and the fourth transmission path 200B of the second transmission 200.

In this example, an optional third freewheel VB1 is provided in the first transmission path 100A in series with the first actuatable clutch C1. Similarly, in this example, an optional fourth freewheel VB2 is provided in the third transmission path in series with the second actuatable clutch C2. In this example, the fourth freewheel VB2 is assigned to the first axle A1.

In this example, the first gear stage is formed by a selective one of the first cooperating gear pair R1 or the second cooperating gear pair R2; the second gear stage is formed by a selective one of the third cooperating gear pair R3 or the fourth cooperating gear pair R4.

In this example, the bicycle transmission 1000 further comprises a third planetary gear 300, which provides a third gear stage between an input 301 of the third planetary gear and an output 302 of the third planetary gear. The input 301 of the third planetary gear and the output 302 of the third planetary gear are assigned to the second axis A2. The third planetary gear 300 comprises a planetary gear set 305 with three rotation elements, in particular a ring gear 310. a planet carrier 320 carrying one or more planet gears 330, and a sun gear 340. One of the rotating elements is non-rotatably attached to a stationary part of the bicycle transmission 1000, here a stationary wheel axle 48 extending along the second axis A2. In this example, the sun gear 340 is attached to the stationary wheel axle 48.

The third planetary gear set 300, in this example, includes a third actuatable clutch C3 and a fourth actuatable clutch C4. Alternatively, the third planetary gear set 300 can include either the third actuatable clutch C3 or the fourth actuatable clutch C4. The third actuatable clutch C3 is arranged on an input side of the planetary gear set, and the fourth actuatable clutch C4 is arranged on an output side of the planetary gear set. In particular, the third actuatable clutch C3 is arranged in a transmission path between the input 301 of the third planetary gear set and the planet carrier 320. The fourth actuatable clutch C4 is arranged in a transmission path between the ring gear 310 and the output 302 of the third planetary gear set. A fifth freewheel V3 is arranged in a transmission path between the input 301 of the third planetary gear set and the ring gear 310. A sixth freewheel V4 is arranged in a transmission path between the planet carrier 320 and the output 302 of the third planetary gear set. An optional seventh freewheel VB3 is arranged in series with the third actuatable clutch C3.

In addition, an optional eighth freewheel VB4 is arranged in series with the fourth actuatable clutch C4.

In this example, the bicycle transmission includes four actuatable clutches, i.e., the first actuatable clutch C1, the second actuatable clutch C2, the third actuatable clutch C3, and the fourth actuatable clutch C4, connected in series. Furthermore, in this example, the first actuatable clutch C1, the second actuatable clutch C2, the third actuatable clutch C3, and the fourth actuatable clutch C4 are identical.

Each of the first, second, third, and fourth actuatable clutches C1, C2, C3, C4 is configured to be selectively in a closed state or an open state. In the closed state, the actuatable clutch couples the clutch input to the clutch output to transmit torque through the clutch, and in the open state, the clutch input is decoupled from the clutch output to transmit no torque through the clutch. Here, the first, second, third, and fourth actuatable clutches C1, C2, C3, C4 are identical. Again, the first, second, third, and fourth actuatable clutches C1, C2, C3, C4 are associated with the second axis. Each of the clutches has one or more clutch elements rotatable about the second axis. The first axis, in this example, has no actuatable clutches associated with it and is thus free of actuatable clutches. In this example, each actuatable clutch is a clutch as shown in WO2018/199757A2 , WO2020/085911A2 or WO2021/080431A1 described.

When the first actuatable clutch C1 is engaged, torque can be transmitted through the first transmission path 100A via the first interacting gear pair R1 from the first transmission input 101 to the first transmission output 102. The first freewheel V1 is exceeded when the first actuatable clutch is engaged. When the first actuatable clutch C1 is engaged, the first actuatable clutch C1 enables torque to be transmitted through the second transmission path 100B via the first freewheel and via the second interacting gear pair R2 from the first transmission input 101 to the first transmission output 102. Likewise, when the second actuatable clutch C2 is engaged, torque can be transmitted through the third transmission path 200A via the third interacting gear pair R3 from the second transmission input 201 to the second transmission output 202. The second actuatable clutch C2 in the open state enables torque to be transmitted through the fourth transmission path 200B via the second freewheel V2 and via the fourth cooperating gear pair R4 from the second transmission input 201 to the second transmission output 102.

When the third actuatable clutch C3 is closed, torque can be transmitted via the third actuatable clutch C3 from the input 301 of the third planetary gear set to the planet carrier 320. The planet carrier can deliver the torque to the ring gear 310 according to a predefined gear ratio. Thus, the fifth freewheel V3 can be exceeded when the third actuatable clutch C3 is closed. When the third actuatable clutch C3 is open, no torque can be transmitted via the third actuatable clutch C3 from the input 301 of the third planetary gear set to the planet carrier. Instead, when the third actuatable clutch C3 is open, torque ment is transmitted via the fifth freewheel V3 from the input 301 of the third planetary gear to the ring gear 310.

Furthermore, when the fourth actuatable clutch C4 is closed, torque can be transmitted via the third actuatable clutch C3 from the ring gear 310 to the output 302 of the third planetary gear set. The sixth freewheel V4 can be exceeded when the fourth actuatable clutch C4 is closed. When the fourth actuatable clutch C4 is open, no torque can be transmitted via the fourth actuatable clutch C4. Instead, when the fourth actuatable clutch C4 is open, torque can be transmitted via the sixth freewheel V4 from the planet carrier 320 to the output 302 of the third planetary gear set.

The exemplary third planetary gear set 300 is accordingly selectively operable according to three different gear ratios, here a speed-reducing gear ratio, a uniform gear ratio, and a speed-increasing gear ratio. The speed-increasing and speed-reducing gear ratios can be inverse to each other. The third gear stage selectively comprises one of the different gear ratios of the third gear set 300.

In the example from 1B Each primary-secondary gear pair of the first transmission 100 meshes together through a direct meshing engagement. Furthermore, each primary-secondary gear pair of the second transmission 200 meshes together through a direct meshing engagement.

The bicycle transmission 1000 further includes a housing 49. The housing 49 contains the first gear 100 and the second gear 200. The housing 49 may further include any additional gear arranged between the first gear 100 and the second gear 200, such as the third planetary gear 300 in this example.

2 shows an exemplary bicycle transmission 1000, which is similar to the example from the 1A and 1B is similar, but each primary-secondary gear pair of the first transmission 100 interacts in a non-meshing manner, here via respective chains 30A, 30B, 40A, 40B. Furthermore, each primary-secondary gear pair of the second transmission 200 interacts in a non-meshing manner, here via a chain. The first axis A1 and the second axis A2 can be arranged such that they are spaced apart from each other, e.g., creating space for an electric drive motor 50. Furthermore, the non-meshing interaction between gear pairs can require less lubrication or even be lubricant-free.

The bicycle transmission 1000, as in the 1 and 2 shown may be a twelve-speed bicycle transmission configured to be selectively operable according to twelve different gear ratios. Shifting between the twelve different gear ratios of the bicycle transmission may be induced by the actuatable clutches of the transmission, specifically the first actuatable clutch C1, the second actuatable clutch C2, the third actuatable clutch C3, and the fourth actuatable clutch C4. No other actuatable components are required for shifting through the twelve different gear ratios of the twelve-speed bicycle transmission 1000. Table 1 shows an example of the gear ratios obtainable by such a twelve-speed bicycle transmission 1000. Table 1 speed Relationship 30/24 R1= 1.00 1 0.50 R1 * R3 * R6 0.63 R2= 1.16 2 0.58 R2*R3*R6 0.72 R3= 0.67 3 0.67 R1*R3*R5 0.83 R4= 1.58 4 0.77 R2*R3*R5 0.96 5 0.89 R1*R3*R7 1.11 6 1.03 R2*R3*R7 1.28 R5= 1.00 7 1.19 R1*R4*R6 1.48 R6= 0.75 8 1.37 R2*R4*R6 1.71 R7= 1.33 9 1.58 R1*R4*R5 1.98 10 1.83 R2*R4*R5 2.29 11 2.11 R1*R4*R7 2.64 12 2.44 R2*R4*R7 3.05 488% 488%

In the example of Table 1, the bicycle transmission 1000 is combined with an offset drive comprising a 30-tooth chainring and a 24-tooth sprocket that interact via a chain. The chainring is driven by the transmission output O. Torque may be transmitted to the sprocket via the chain. The sprocket may be connected to a driven wheel of the bicycle, such as a rear wheel of the bicycle. The interaction of the chainring, here with 30 teeth, and the sprocket, here with 24 teeth, may provide an additional fixed gear ratio to the transmission output O, which would result in the gear ratios shown in the right-hand column of Table 1. The resulting bicycle gear ratio range in this example is 488%, with a substantially constant step size between successive gear ratios of approximately 15%. The bicycle transmission 1000 could obviate the need for conventional derailleur systems, where the chain must be shifted between multiple sprockets and/or chainrings to change gears. Thus, only a single chainring and a single sprocket may be provided, e.g., according to this example. However, it is understood that the bicycle transmission 1000 may be combined with a conventional derailleur system with multiple chainrings and/or multiple sprockets, for example, to expand the range of gear ratios.

The 3A and 3B show an example of a bicycle transmission 1000, wherein the bicycle transmission 1000 includes a fourth continuously variable transmission (CVT) 400 instead of the third planetary gear set 300. The CVT 400, in this example, is particularly a ratchet-type CVT that includes one or more overrunning clutches and/or one-way drives. The CVT 400 is operatively disposed between the first transmission 100 and the second transmission 200 and provides a fourth gear ratio. The CVT 400 is configured to be selectively operable according to a selective one of a plurality of different gear ratios within a continuous range of gear ratios.

The CVT 400 includes a first drive element 410 and a second drive element 420. Here, the first drive element 410 forms or is coupled to the CVT input 401. Here, the second drive element 410 forms or is coupled to the CVT output 402. It should be understood that the CVT can also be used in reverse, i.e., with the first drive element 410 forming or being coupled to the CVT output 402 and the second drive element 420 forming or being coupled to the CVT input 401.

The first drive element 410 is rotatable about a first CVT axis 407. The second drive element 420 is rotatable about a second CVT axis 406 parallel to the first CVT axis 407. Here, the second CVT axis 406 coincides with the second axis A2. The first drive element 410 and the second drive element 420 are movable relative to one another in a direction transverse to the first CVT axis 407 and the second CVT axis 406. In particular, the first drive element 410 is movable from a concentric position in which the first CVT axis 407 coincides with the second CVT axis 406, to an eccentric position in which the first CVT axis 407 is offset from the second CVT axis 406. Torque can be transmitted from the first drive element 410 to the second drive element 420 by means of coupling elements 411. The coupling elements 411 are arranged concentrically with respect to the first CVT axis 407 at a constant first radius from the first CVT axis 407. The coupling elements 411 are located at a variable second radius from the second CVT axis 406.

By moving the first input element 410 relative to the second input element 420, the gear ratio for the fourth gear stage can be varied. The coupling elements 411 are movable in a tangential direction with respect to the first input element 410. The input element 410, in this example, comprises a first concentric guide 412 that extends concentrically around the first CVT axis 407 in the first radius. The tangential movement of the coupling elements 411 around the first CVT axle 407 is guided by a concentric guide 412. The concentric guide 412 prevents radial movement of the coupling elements 411 relative to the first CVT axle 407 in order to keep the coupling elements 411 at the constant first radius from the first CVT axle 407. The coupling elements are thus radially coupled to the first drive element 410 relative to the first CVT axle 407.

With respect to the first CVT axis 407, the coupling elements 411 are tangentially coupled to the first drive element 410. For this purpose, in this example, the coupling elements 411 and the first concentric guide 412 form or include a one-way coupling. The one-way coupling is arranged to enable tangential movement of the coupling elements 411 relative to the first concentric guide 412 in one direction and to block tangential movement of the coupling elements 411 relative to the first concentric guide 412 in the other, opposite direction. Therefore, the first drive element 410 can drive the coupling elements 411 in rotation about the first CVT axis 407 in one direction, while allowing the coupling elements 411 to freewheel relative to the first drive element 410 in the other direction.

The coupling elements 411 are further movable relative to the second drive element 420 in a radial direction with respect to the second CVT axis 406. In a tangential direction relative to the second CVT axis 406, the coupling elements 411 are coupled to the second drive element 420. The second drive element 420 comprises, in particular, radial guides (not shown), e.g., radial slots, which extend radially with respect to the second CVT axis 406. The coupling elements 411 are guided in the radial direction with respect to the second CVT axis 406 by the radial guides.

The gear ratio of the CVT 400, ie, for the fourth gear stage, is variable by moving the first drive element 410 relative to the second drive element 420 in a direction transverse to the second axis A2. An electric actuator may, for example, be provided for actuating the movement of the first drive element 410 relative to the second axis A2 to change the gear ratio for the fourth gear stage. In the example of the 3A and 3B The first transmission 100 includes only one cooperating gear pair R1. The first gear stage in this example has a fixed gear ratio. Here, the cooperating gear pair R1 of the first transmission 100 interacts non-meshingly via a chain. This facilitates the movement of the first input element 410 of the CVT 400 to be moved relative to the second axis A2. The second transmission 200 includes two cooperating gear pairs R3, R4 for selectively providing the second gear stage. Here, the cooperating gear pairs R3 and R4 of the second transmission 200 also interact non-meshingly via respective chains.

The 4A and 4B show an example of a bicycle transmission 1000 with a first transmission 100, a fourth continuously variable transmission (CVT) 400, a third planetary transmission 300, and a second transmission 200 arranged in series. The first transmission 100 provides a first gear stage between the first axis A1 and the second axis A2, and the second transmission provides a second gear stage between the second axis A1 and the first axis A2. The third planetary transmission 300 and the fourth continuously variable transmission 400 are associated with the second axis A2 and each provide a third gear stage and a fourth gear stage. In this example, the third planetary transmission 300 is similar to the one shown in 2 planetary gear 300 shown.

The fourth continuously variable transmission may be similar to the CVT, as described in the pending patent application PCT/ EP1022/060920 revealed.

The 5A and 5B show an example of a bicycle gear 1000 similar to the 4A and 4B , but with an alternative third planetary gear set 300. In this example, the third planetary gear set 300 includes the fourth actuatable clutch C4 and not the third actuatable clutch C3. Thus, in this example, the third planetary gear set is selectively operable according to a maximum of two different gear ratios, here a uniform gear ratio and a non-uniform gear ratio. The non-uniform gear ratio is, in particular, a speed-reducing gear ratio. Furthermore, the bicycle transmission in this example is shown to include an electric drive motor 50.

The 6A and 6B show an example of a bicycle transmission 1000, wherein the transmission input I is assigned to the first axle A1 and the transmission output O is assigned to the second axle A2. Thus, the first axle A1, here the first CVT axle, and the second axle A2, here the output axle, are separated from each other. which is offset. The offset between the first axis A1 and the second axis A2 can be greater than a chainring radius of a chainring 19 driven by the transmission output O. The transmission comprises a first gear 100, which here corresponds to the first gear 100 as shown in the 3-5 shown. The bicycle transmission 1000 in this example further includes a third planetary gear 300 and a fourth continuously variable transmission 400. It should be understood that the bicycle transmission 1000 alternatively includes only the third planetary gear 300 or only the fourth continuously variable transmission 400.

In this example, the bicycle transmission comprises a further third planetary gear 300'. The further third planetary gear 300 has an alternative layout compared to the third planetary gear 300 in this example. It is understood that this layout of the further third planetary gear 300' can be applied in any of the bicycle transmissions described in this document. Here, the planetary gear set 305' of the further planetary gear 300' in this example is a sun gearless planetary gear set, i.e., it does not include a sun gear. Alternatively, the planetary gear set 305' of the further third planetary gear 300' can be a ring gearless planetary gear set, i.e., it does not include a ring gear. Here, the planetary gear set 305' comprises two ring gears 310A', 310B' and a planet carrier 320' that carries one or more planet gears 330'. The planet carrier 320' is non-rotatably fixed to the stationary wheel axle 48. Here, each planetary gear 330' is a stepped planetary gear 330'. Each stepped planetary gear 330' comprises a large radius part and a small radius part that are rotatably secured to each other. Here, the small radius part meshes with a small radius ring gear 310A', while the large radius part meshes with a large radius ring gear.

The further third planetary gear set 300' is operatively arranged between the fourth continuously variable transmission 400 and the third planetary gear set 300 in this example. It is understood that alternative serial configurations of the third planetary gear set 300, the fourth continuously variable transmission 400, and the further third planetary gear set 300' may also be contemplated. For example, any one or more of the third planetary gear set 300, the fourth continuously variable transmission 400, and the further third planetary gear set 300' may be associated with the first axis A1, e.g., arranged on an input side of the first transmission 100 between the transmission input I and the first transmission input 101.

The 7A , 7B and 8A , 8B show a bicycle transmission 1000 including a fourth continuously variable transmission 400 disposed between the first transmission 100 and the second transmission 200, the fourth continuously variable transmission 400 including a first drive member 410 and a second drive member 420, and further including a third drive member 430. Torque can be transmitted between the first drive member 410 and the second drive member 420, and between the second drive member 420 and the third drive member 430. The third drive member 430 is similar to the first drive member 410.

The fourth continuously variable transmission 400 includes first coupling elements 411 for coupling the first input element 410 to the second input element 420 and second coupling elements 421 for coupling the second input element 420 to the third input element 430.

The second drive element 420 comprises a first body 420A with the first radial guides associated therewith for cooperating with the first coupling elements 411 and a second body 420B with second radial guides associated therewith for cooperating with the second coupling elements 421. The first body 420A and the second body 420B are fixedly coupled to each other and rotatable about the second CVT axis 406.

In the example from the 7A , 7B The first drive element 410 and the third drive element 430 are both rotatable about the first CVT axis 407, wherein the first drive element 410 comprises a first concentric guide 412 for cooperating with the first coupling elements 411 and the third drive element 430 comprises a second concentric guide 422 for cooperating with the second coupling elements 421. When driven in the drive direction, the first drive element 410 drives the second drive element 420 via the first coupling elements 411 and the second drive element 420 drives the third drive element 430 via the second coupling elements 421.

The 8A and 8B show an alternative example, wherein the second drive element 420 comprises a concentric guide. Specifically, the first body 420A comprises the first concentric guide 412, and the second body 420B comprises the second concentric guide 422. Here, the first drive element 410 and the third drive element 430 comprise radial guides.

In the examples from the 7A , 7B and 8A , 8B The first input element 410 forms the CVT input 401 or is coupled thereto, and the third input element 430 forms the CVT output 402 or is coupled thereto. A primary gear ratio of the continuously variable transmission can be obtained between the first input element 410, here the input of the CVT 400, and the second input element 420. A secondary gear ratio of the continuously variable transmission can be obtained between the second input element 420 and the third input element 430, here the output of the CVT 400. The gear ratio of the continuously variable transmission of the CVT 400 between the first input element 410 and the third input element 430 can be obtained accordingly, being a product of the primary and secondary gear ratios. Thus, the resulting range of gear ratios of the CVT 400 of the example can be determined from the 7A , 7B , 8A , 8B compared to the example in the previous figures. In particular, the primary and secondary gear ratios can be equal to each other.

In the examples from the 7A , 7B and 8A , 8B The second drive element 420, which here includes two bodies 420A, 420B, is moved relative to the stationary wheel axle 48, while the first drive element 410 and the third drive element 430 are rotatably mounted on the stationary wheel axle 48. It is understood that in an alternative arrangement, the second drive element 420 may be rotatably mounted on a stationary part, and the wheel axle 48, including all components mounted thereon, may be moved relative to the second drive element 420.

In the 7A and 8A the first gear is selectively operable according to two gear ratios, with each cooperating gear pair R1, R2, R3, R4 meshing together. 7B and 8B show a similar example as in 7A or 8A wherein each cooperating gear pair R1, R2, R3, R4 cooperating in a non-meshing manner via a respective chain or belt 30A, 30B, 40A, 40B.

9A and 9B show a bicycle 10. The bicycle 10 comprises a frame 2 with a front fork 5 and a rear fork 7, as well as a front wheel 11 and a rear wheel 13 located in the front and rear forks, respectively. The bicycle 10 further comprises a crank 17 and a front chainring 19. In this example, the bicycle transmission 1000 is inserted between the crank 17 and the front chainring 19. The bicycle transmission 1000 is thus designed as a crank shift. The bicycle 10 also comprises a rear sprocket 21 connected to a rear wheel hub 22 of the rear wheel 13, with a chain 23 wound over the front chainring 19 and the rear sprocket 21. The bicycle 10 also includes a control unit 6, which is connected here to the handlebar 31, for controlling the bicycle transmission 1000, in particular any one or more of the actuatable clutches of the bicycle transmission 1000. Here, the bicycle 10 does not include a front and rear derailleur. The bicycle 10 may additionally include a hub gear on the rear wheel hub 22.

In the example from 9A The transmission input I and the transmission output O of the transmission 1000 are assigned to the first axis A1. Thus, the crank 17 and the front chainring 19 are rotatable about the first axis A1 of the bicycle transmission 1000. In the example from 9B The transmission input I of the transmission 1000 is assigned to the first axis A1, while the transmission output O of the transmission 1000 is assigned to the second axis A2. Thus, the crank 17 is rotatable about the first axis A1, and the front chainring 19 is rotatable about the second axis A2 of the bicycle transmission 1000.

In this specification, the invention is described with reference to specific examples of embodiments of the invention. However, it will be apparent that various modifications and changes may be made thereto without departing from the spirit of the invention. For the purpose of clarity and concise description, features are described in this specification as part of the same or separate embodiments, but alternative embodiments are also contemplated that include combinations of all or some of the features described in these separate embodiments.

However, other modifications, variations, and alternatives are also possible. Accordingly, the specifications, drawings, and examples are to be understood in an illustrative and not a restrictive sense.

In the claims, reference signs placed in parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of features or steps other than those listed in a claim. Furthermore, the The words "a" and "an" are not to be construed as being limited to "only one," but are instead used to mean "at least one" and do not exclude a plurality. The mere fact that certain measures are recited in different patent claims does not indicate that a combination of those measures cannot be advantageously used.

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2018/199757A2 [0041, 0123]
• WO 2020/085911A2 [0041, 0123]
• WO 2021/080431A1 [0041, 0123]
• EP 1022/060920 [0101, 0141]

Claims (40)

A bicycle transmission comprising: a transmission input and a transmission output, each associated with a first axle; a second axle offset from the first axle; a first transmission providing a first gear stage between a first transmission input associated with the first axle and a first transmission output associated with the second axle; a second transmission providing a second gear stage between a second transmission input associated with the second axle and a second transmission output associated with the first axle; a third planetary transmission and/or a fourth continuously variable transmission operatively disposed between the first transmission and the second transmission; wherein the third planetary transmission provides a third gear stage between a third transmission input associated with the second axle and a third transmission output associated with the second axle, wherein the third planetary transmission is configured to provide the third gear stage to selectively have one of a plurality of different third gear ratios; wherein the fourth continuously variable transmission provides a fourth gear stage between a fourth transmission input associated with the second axle and a fourth transmission output associated with the second axle. Bicycle gears according to Claim 1 , wherein the third planetary gear has three rotating elements, wherein a third of the rotating elements is non-rotatably attached to a stationary part. Bicycle gears according to Claim 2 , wherein the third of the rotating elements includes or is a sun gear. Bicycle gears according to Claim 1 or 2 , wherein the third planetary gear comprises a third actuatable clutch and/or a fourth actuatable clutch; wherein the third actuatable clutch is arranged in a transmission path between the input of the third planetary gear and a first of the rotating elements and includes a first freewheel in a transmission path between the input of the third planetary gear and a second of the rotating elements, and wherein the fourth actuatable clutch is arranged in a transmission path between the second of the rotating elements and the output of the third planetary gear and includes a second freewheel in a transmission path between the first of the rotating elements and the output of the third planetary gear. Bicycle gears according to Claim 4 , wherein the first of the rotating elements is a planet carrier carrying one or more planet gears, and the second of the rotating elements is a ring gear, or wherein the first of the rotating elements is a ring gear and the second of the rotating elements is a planet carrier carrying one or more planet gears. Transmission system according to one of the Claims 4 or 5 , wherein the third actuatable clutch and the fourth actuatable clutch are positive clutches configured to deliver torque in two rotational directions. Bicycle transmission according to one of the Claims 4 - 6 wherein each of the third actuatable clutch and the fourth actuatable clutch is configured to be coupled and uncoupled under load. Transmission system according to one of the Claims 4 - 7 , comprising at least one electrical actuator designed to actuate the third actuatable clutch and the fourth actuatable clutch, in particular comprising a third electrical actuator designed to actuate the third actuatable clutch and a fourth electrical actuator designed to actuate the fourth actuatable clutch. Bicycle transmission according to one of the Claims 4 - 8 , wherein the third actuatable clutch and the fourth actuatable clutch are independently actuatable. Bicycle transmission according to one of the Claims 4 - 9 , wherein the third actuatable clutch is identical to the fourth actuatable clutch. Bicycle transmission according to one of the Claims 4 - 10 , wherein the third planetary gear is selectively operable according to a uniform gear ratio. Bicycle transmission according to one of the Claims 4 - 11 , wherein the planetary gear is selectively operable according to a speed-increasing and/or a speed-reducing gear ratio, wherein optionally the speed-increasing gear ratio and the speed-reducing gear ratio are inverse to each other. Bicycle transmission according to one of the preceding claims, wherein the first gear stage is formed by a cooperating gear pair with a primary gear rotatable about the first axis and a secondary gear rotatable about the second axis. A bicycle transmission according to any one of the preceding claims, wherein the first transmission for providing the first gear stage is configured to selectively have one of a plurality of different first gear ratios. Bicycle gears according to Claim 14 , wherein the first transmission comprises a first actuatable clutch for shifting the first transmission from one of the plurality of first gear ratios to another and/or vice versa. Bicycle gears according to Claim 15 , if one of the Claims 4 - 12 dependent, wherein the first actuatable clutch is identical to the third actuatable clutch and/or the fourth actuatable clutch. Bicycle gears according to Claim 15 or 16 , wherein the first actuatable clutch is assigned to the first axle or the second axle. Bicycle transmission according to one of the Claims 15 - 17 , wherein the first gear stage is selectively formed by a first cooperating gear pair arranged in a first transmission path or a second cooperating gear pair arranged in a second transmission path parallel to the first transmission path, each of the first and second cooperating gear pairs comprising a primary gear rotatable about the first axis and a secondary gear rotatable about the second axis, wherein the first actuatable clutch is configured to selectively enable torque transmission through any one of the first transmission path or the second transmission path from the first transmission input to the first transmission output. Bicycle gears according to Claim 18 , wherein the first actuatable clutch is arranged in the first transmission path connected in series with the first cooperating gear pair, and a fifth freewheel is arranged in the second transmission path connected in series with the second cooperating gear pair, or vice versa, wherein optionally the first cooperating gear pair provides a greater output speed than the second cooperating gear pair. Bicycle gears according to Claim 18 or 19 wherein the primary gear and the secondary gear of each of the first and/or second cooperating gear pair mesh with each other, or wherein the primary gear and the secondary gear of each of the first and/or second cooperating gear pair do not mesh with each other, such as via a respective endless drive element, e.g., a chain or belt. Bicycle transmission according to one of the preceding claims, wherein the second gear stage is formed by a cooperating gear pair with a primary gear rotatable about the second axis and a secondary gear rotatable about the first axis. A bicycle transmission according to any one of the preceding claims, wherein the second transmission for providing the second gear stage is configured to selectively have one of a plurality of different second gear ratios. Bicycle gears according to Claim 22 , wherein the second transmission comprises a second actuatable clutch for shifting the second transmission from one of the plurality of second gear ratios to another and/or vice versa. Bicycle gears according to Claim 23 , if one of the Claims 4 - 12 dependent, wherein the second actuatable clutch is identical to the third actuatable clutch and/or the fourth actuatable clutch. Bicycle gears according to Claim 23 or 24 , wherein the second actuatable clutch is assigned to the first axle or the second axle. Bicycle transmission according to one of the Claims 23 - 25 , wherein the second gear stage is selectively formed by a third cooperating gear pair arranged in a third transmission path or a fourth cooperating gear pair arranged in a fourth transmission path parallel to the third transmission path, each of the third and fourth cooperating gear pairs comprising a primary gear rotatable about the second axis and a secondary gear rotatable about the first axis, wherein the second actuatable clutch is configured to selectively enable torque transmission through any one of the third transmission path or the fourth transmission path from the second transmission input to the second transmission output. Bicycle gears according to Claim 26 , wherein the second actuatable clutch is arranged in the third transmission path connected in series with the third cooperating gear pair, and a freewheel is arranged in the fourth transmission path connected in series with the fourth cooperating gear pair, or vice versa, optionally wherein the third cooperating gear pair provides a greater output speed than the fourth cooperating gear pair. Bicycle gears according to Claim 26 or 27 wherein the primary gear and the secondary gear of each of the third and/or fourth cooperating gear pairs mesh with each other, or wherein the primary gear and the secondary gear of each of the third and/or fourth cooperating gear pairs do not mesh with each other, such as via a respective endless drive element, e.g., a chain or belt. A bicycle transmission according to any one of the preceding claims, wherein the fourth continuously variable transmission (CVT) includes: a first input member rotatable about a first CVT axis; a second input member rotatable about a second CVT axis, the first input member being movable relative to the second input member in a direction transverse to the first CVT axis and the second CVT axis; coupling elements provided at a constant first radius from the first CVT axis and a variable second radius from the second CVT axis, or at a constant first radius from the second CVT axis and a variable second radius from the first CVT axis, for transmitting torque between the first input member and the second input member. Transmission system according to Claim 29 , wherein the coupling elements are coupled to the second drive element in a tangential direction and are movable in a radial direction relative to the second drive element, wherein the coupling elements are coupled to the first drive element in a radial direction in the first radius from the first CVT axis and are movable in a first tangential direction relative to the first drive element, and wherein the coupling elements are coupleable to the first drive element in a second tangential direction opposite to the first tangential direction. Bicycle gears according to Claim 29 or 30 , wherein the second CVT axis coincides with the second axis and wherein the first drive member is movable relative to the second drive member to an eccentric position offset from the second axis. Bicycle transmission according to one of the Claims 29 - 31 , if from Claim 13 dependent, wherein the first input element of the CVT is attached to or integrated with the secondary gear of the first transmission stage. Bicycle gears according to Claim 32 , wherein the primary gear and the secondary gear of the first gear stage do not mesh with each other, such as via an endless drive element. Bicycle transmission according to one of the preceding claims, comprising a transmission housing containing the first transmission and the second transmission and further containing the third planetary transmission and/or the fourth continuously variable transmission. Bicycle transmission according to one of the preceding claims, comprising an electric drive motor with a motor output axis coinciding with the first axis. Bicycle gears according to Claim 35 , wherein the electric drive motor is configured to output a maximum rated power of at most 10 kW, preferably at most 4 kW. Bicycle gears according to Claim 35 or 36 , if from Claim 32 dependent, with the electric drive motor being contained in the gearbox housing. Bicycle transmission according to one of the preceding claims, comprising a crank connected to the transmission input to be rotatably driven about the first axis, and a chainring connected to the transmission output to be rotatably driven about the first axis. A bicycle transmission comprising: a transmission input associated with a first axle and a transmission output associated with a second axle offset from the first axle; a first transmission providing a first gear stage between a first transmission input associated with the first axle and a first transmission output associated with the second axle; a third planetary transmission and/or a fourth continuously variable transmission connected in series with the first transmission; wherein the third planetary transmission provides a third gear stage between a third transmission input associated with one of the first axle and the second axle and a third transmission output associated with the same from the first axle or the second axle, wherein the third planetary transmission is configured to provide the third gear stage to selectively have one of a plurality of different third gear ratios; wherein the fourth continuously variable transmission provides a fourth gear stage between a fourth transmission input associated with one of the first axle or the second axle and a fourth transmission output associated with the same from the first axle or the second axle. Bicycle comprising a bicycle transmission according to one of the preceding claims.