CN203854815U - Bicycle central power take-off mechanism - Google Patents

Abstract

The utility model discloses a put power take off mechanism in bicycle, it includes a casing, a crank axle, a fluted disc base, a motor and a drive unit, this fluted disc base has a transmission external member that stretches into in this casing, this drive unit includes a first ring gear, a second ring gear, a sun gear and a plurality of planet wheel, this first ring gear rotationally locates in this casing and connects in this transmission external member, this second ring gear sets firmly in this casing, this sun gear is the unidirectional rotation with this rotor and links the relation, each this planet wheel has a first tooth portion and a second tooth portion, the first tooth portion of each this planet wheel simultaneously with this sun gear and second ring gear meshing, the second tooth portion and this first ring gear meshing of each this planet wheel. Therefore, the transmission unit of the utility model has the characteristics of high transmission ratio and small volume.

Description

Bicycle central power take-off mechanism

technical field

The utility model relates to a power output mechanism of a bicycle, in particular to a central power output mechanism of a bicycle.

Background technique

The traditional electric-assist bicycle obtains forward power through the pedaling force of the rider combined with the assistance provided by a power output mechanism (such as a mid-mounted motor), so that the electric-assist bicycle will not cause too much damage to the rider's physical strength. burden, and can achieve the effect of fitness in addition to leisure.

As far as the general mid-mounted motor is concerned, because it has many parts and components, it is easily affected by the machining error of each part after the assembly is completed, resulting in abnormal noise or vibration during operation. In order to solve the above problems, the Japanese Patent No. 3974386 discloses the "reduction gear mechanism of an electric drive device" by setting a plurality of helical gears between the output shaft of the motor and the crankshaft to achieve the effect of eliminating machining errors, but these components Between different axial configurations, there will be a problem of increased volume.

In order to reduce the volume and eliminate the processing errors between the components, the applicant recently proposed the patent case of "Central Power Output Mechanism of Electric Assisted Bicycle" No. The gear is integrated into the sun gear as the main power transmission element, thereby reducing the volume and taking into account the purpose of eliminating machining errors. The fly in the ointment is that the transmission unit uses the planetary gear to mesh between the sun gear and a fixed ring gear, and then the power is output to the gear plate by the planetary carrier, so the deceleration effect is limited, and a high-power motor cannot be used. And in order to increase the reduction ratio, it is necessary to use a ring gear with a larger outer diameter and number of teeth, and such a design will also increase the volume of the transmission unit.

Utility model content

In view of this, the main purpose of the utility model is to provide a bicycle mid-mounted power output mechanism with a relatively high reduction ratio and a small volume occupied by the transmission unit.

In order to achieve the aforementioned and other purposes, the utility model provides a central power output mechanism for a bicycle, which includes a casing, a crankshaft, a chainring base, a motor and a transmission unit, and the crankshaft rotatably passes through the Located in the case, the chainring base is sheathed on the crankshaft and has a unidirectional rotational connection relationship with the crankshaft. The chainring base has a transmission sleeve extending into the casing. The motor is set In the casing, and the motor has a stator fixed on the casing and a rotor rotatably sleeved on the crankshaft, the transmission unit includes a first ring gear, a second ring gear, a The sun gear and several planetary gears, the first ring gear is rotatably arranged in the casing and connected to the transmission sleeve, the second ring gear is fixed in the casing, and the sun gear and the rotor are unidirectional Rotation connection relationship, each of the planetary gears has a first tooth portion and a second tooth portion, the first tooth portion of each of the planetary gears meshes with the sun gear and the second ring gear at the same time, and the second tooth portion of each of the planetary gears meshes with the first ring gear.

Wherein, a first one-way ratchet is arranged between the chainring base and the crankshaft.

Wherein, a second one-way ratchet is arranged between the sun gear and the rotor.

Wherein, a second one-way ratchet is set between the sun gear and the rotor.

Wherein, the rotor is located at the radial inner side of the stator.

Wherein, the transmission unit further includes a planetary carrier, the planetary carrier is rotatably sleeved on the crankshaft, and the planetary gear is rotatably arranged on the planetary carrier.

Wherein, the planet carrier has a first frame, a second frame and a plurality of planetary shafts arranged between the first and second frames, and the planetary wheels are respectively sleeved on the planetary shafts and located on the first and second between the two brackets.

Wherein, the first bracket is rotatably sleeved on the crankshaft, and the second bracket is rotatably sleeved on the sun gear.

Wherein, the transmission unit further includes a planetary carrier, the planetary carrier is rotatably sleeved on the crankshaft, and the planetary gear is rotatably arranged on the planetary carrier.

Wherein, the planet carrier has a first frame, a second frame and a plurality of planetary shafts arranged between the first and second frames, and the planetary wheels are respectively sleeved on the planetary shafts and located on the first and second Between the two brackets, the first bracket is rotatably sleeved on the crank shaft, and the second bracket is rotatably sleeved on the sun gear.

Beneficial effects of the present utility model: through the aforementioned design, the power of the motor is output to the base of the toothed plate through the sun gear, the planetary gear and the first ring gear in sequence, that is, one more deceleration (the planetary gear and the first ring gear) than the existing design. deceleration between a ring of gears), so the reduction ratio of the transmission unit of the utility model can be greatly increased, so that a motor with higher efficiency can be used, and at the same time, under the condition of one more deceleration, you can choose a motor with a smaller outer diameter The first and second ring gears with the same number of teeth can reduce the volume occupied by the transmission unit.

Description of drawings

Fig. 1 is a perspective view of a preferred embodiment of the utility model.

Fig. 2 is an exploded view of a preferred embodiment of the utility model.

Fig. 3 is a longitudinal sectional view of a preferred embodiment of the present invention.

Fig. 4 is a transverse cross-sectional view of a preferred embodiment of the present invention, mainly showing the unidirectional rotation connection relationship between the sun gear and the rotor.

Fig. 5 is a transverse sectional view of a preferred embodiment of the present invention, mainly showing the meshing relationship between the planetary gear, the sun gear and the second ring gear.

Fig. 6 is a transverse sectional view of a preferred embodiment of the present invention, mainly showing the meshing relationship between the planetary gear and the first ring gear.

【Symbol Description】

Chassis 10

first housing 11

Second housing 12

crankshaft 20

Sprocket base 30

Base body 31

Transmission Kit 32

The first one-way ratchet 35

Motor 40

Stator 41

Rotor 42

Transmission unit 50

First ring gear 51

Second ring gear 52

Sun wheel 53

Planetary gear 54

first tooth portion 541

Second tooth part 542

The second one-way ratchet 55

Planet carrier 56

First bracket 561

Second bracket 562

Planetary shaft 563

Detailed ways

Please refer to Fig. 1 to Fig. 3, in the preferred embodiment of the present utility model, a kind of bicycle central power take-off mechanism comprises a casing 10, a crankshaft 20, a sprocket base 30, a motor 40 and a Transmission unit 50.

The casing 10 has a first casing 11 and a second casing 12 disposed on one side of the first casing 11, and an accommodating space is enclosed between the first and second casings 11 and 12, and the first , The second housings 11 and 12 respectively have a shaft hole for the crank shaft 20 to pass through.

The crankshaft 20 is rotatably installed in the casing 10 , and its two ends pass through the shaft holes on both sides of the casing 10 , which can be connected to a crank (not shown) of a bicycle.

The chainring base 30 is sleeved on the crankshaft 20 and has a unidirectional rotational connection relationship with the crankshaft 20. The "unidirectional rotational connection relationship" mentioned in this article means that the two elements are linked in one direction of rotation, and in the other direction of rotation. The upper two elements can rotate relatively. In order to realize the unidirectional rotational connection between the chainring base 30 and the crankshaft 20 , a first one-way ratchet 35 or other one-way devices may be provided between the chainring base 30 and the crankshaft 20 . In this embodiment, the chainring base 30 includes a base body 31 and a transmission kit 32. The base body 31 can be used for installing a bicycle chainring (not shown), and the transmission kit 32 extends into the casing 10. . In this embodiment, the transmission sleeve 32 is connected to the base body 31 by screws, but in other possible embodiments, the base body 31 and the transmission sleeve 32 can be fixed by other fixing means or integrally formed. In addition, the base body 31 can also be integrally formed with the toothed disc.

The motor 40 is arranged in the casing 10, which has a stator 41 fixed on the casing 10 and a rotor 42 rotatably sleeved on the crankshaft 20, and the rotor 42 is located at the radial inner side of the stator 41, that is, The motor 40 in this embodiment is an inner rotor motor.

The transmission unit 50 includes a first ring gear 51 , a second ring gear 52 , a sun gear 53 and a plurality of planetary gears 54 . The first ring gear 51 is rotatably disposed in the casing 10 and connected to the transmission kit 32 , and the first ring gear 51 and the transmission kit 32 can be fixed through fixing parts, tight fitting, embedding or even integral molding. The second ring gear 52 is fixed inside the casing 10 , and the two ring gears can be fixed by but not limited to the aforementioned methods. The sun gear 53 and the rotor 42 are connected in one-way rotation, and as shown in FIG. 4 , a second one-way ratchet 55 or other one-way device may be provided between the sun gear 53 and the rotor 42 . Each of the planetary gears 54 has a first tooth portion 541 and a second tooth portion 542. As shown in FIG. Also as shown in FIG. 6 , the second tooth portion 542 of each planetary gear 54 meshes with the first ring gear 51 . In order to allow each planetary gear 54 to be accurately positioned and improve the stability of operation, the transmission unit 50 may also include a planetary carrier 56, which is rotatably sleeved on the crankshaft 20, and the planetary gear 54 is rotatably It is provided on the planetary carrier 56 . As a preferred arrangement, the planetary carrier 56 can have a first carrier 561, a second carrier 562 and several planet shafts 563 arranged between the first and second carrier 561, 562, and the planetary gear 54 respectively sleeved on the planet shafts 563 and located between the first and second brackets 561, 562, wherein the first bracket 561 is rotatably sleeved on the crankshaft 20, and a There is a bearing; the second bracket 562 is rotatably sleeved on the sun gear 53 , and a bearing may also be provided between the second bracket 562 and the sun gear 53 . Of course, the form of the planet carrier 56 is not limited to the one shown in this embodiment.

Through the above-mentioned design, the power of the motor 40 will be transmitted to the chainring base 30 through the sun gear 53, the planetary gear 54 and the first ring gear 51 in order to make it rotate. At this time, the planetary gear 54 will rotate around The sun gear 53 revolves, wherein the power is decelerated for the first time between the sun gear 53, the first tooth portion 541 of the planetary gear 54 and the second ring gear 52, and then between the second tooth portion 542 of the planetary gear 54 and the second ring gear 52. The second deceleration is carried out between the first ring gear 51, so the transmission unit 50 of the present utility model has a higher reduction ratio, and therefore a high-power motor 40 and smaller-diameter first and second ring gears 51, 52 can be selected. , so that the volume occupied by the transmission unit 50 is reduced.

In the internal test conducted by the applicant, the reduction ratio of the transmission unit of the M453636 patent is only 9.6, while the reduction ratio of the reduction unit of this preferred embodiment can reach 22.1, and the diameter ratio of the two is 132:107. These simulations fully show that the utility model has a significantly improved reduction ratio compared with the existing design, and can also reduce the volume of the transmission unit, which is indeed an optimized design with remarkable effects.

Finally, it must be explained again that the constituent elements disclosed in the foregoing embodiments of the present invention are only for illustration and are not intended to limit the scope of the present invention. The substitution or change of other equivalent elements shall also be included in this invention. covered by the claims of the utility model.

Claims (10)

1. A central power take-off mechanism for a bicycle, characterized in that it comprises: a casing; A crank shaft is rotatably installed in the casing; A chainring base is sheathed on the crank shaft and has a unidirectional rotational connection with the crank shaft. The chainring base has a transmission sleeve extending into the casing; A motor is arranged in the casing, the motor has a stator fixed to the casing and a rotor rotatably sleeved on the crankshaft; and A transmission unit includes a first ring gear, a second ring gear, a sun gear and several planetary gears, the first ring gear is rotatably arranged in the housing and connected to the transmission sleeve, the second ring The gears are fixed in the casing, the sun gear and the rotor are connected in one-way rotation, each of the planetary gears has a first tooth portion and a second tooth portion, and the first tooth portion of each of the planetary gears is simultaneously connected with the The sun gear meshes with the second ring gear, and the second tooth portion of each planetary gear meshes with the first ring gear. 2 . The central power output mechanism of a bicycle according to claim 1 , wherein a first one-way ratchet is disposed between the chainring base and the crankshaft. 3 . 3. The central power output mechanism of a bicycle as claimed in claim 1, wherein a second one-way ratchet is provided between the sun wheel and the rotor. 4. The central power output mechanism of a bicycle as claimed in claim 2, wherein a second one-way ratchet is provided between the sun gear and the rotor. 5. The central power output mechanism for a bicycle according to any one of claims 1 to 4, wherein the rotor is located radially inside the stator. 6. The central power output mechanism of a bicycle according to any one of claims 1 to 4, wherein the transmission unit further comprises a planetary carrier, which is rotatably sleeved on the crankshaft, and the The planetary gear is rotatably arranged on the planetary carrier. 7. The central power take-off mechanism of a bicycle as claimed in claim 6, wherein the planetary carrier has a first frame, a second frame and a plurality of planetary shafts arranged between the first and second frames, so that The planetary wheels are sheathed on the planetary shafts respectively and located between the first and second brackets. 8 . The central power output mechanism of the bicycle as claimed in claim 7 , wherein the first bracket is rotatably sleeved on the crank shaft, and the second bracket is rotatably sleeved on the sun gear. 9. The central power output mechanism of a bicycle as claimed in claim 5, wherein the transmission unit further comprises a planet carrier, the planet carrier is rotatably sleeved on the crankshaft, and the planet wheel is rotatably set on the planet carrier. 10. The central power output mechanism of a bicycle as claimed in claim 9, wherein the planet carrier has a first frame, a second frame and a plurality of planet shafts arranged between the first and second frames, so that The planetary gears are respectively sleeved on the planetary shafts and located between the first and second brackets, the first bracket is rotatably sleeved on the crankshaft, and the second bracket is rotatably sleeved on the sun gear .