CN121039011A - Steering mechanism - Google Patents
Steering mechanismInfo
- Publication number
- CN121039011A CN121039011A CN202480020878.3A CN202480020878A CN121039011A CN 121039011 A CN121039011 A CN 121039011A CN 202480020878 A CN202480020878 A CN 202480020878A CN 121039011 A CN121039011 A CN 121039011A
- Authority
- CN
- China
- Prior art keywords
- stator
- steering device
- steering
- electric motor
- rotor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
- B62D5/005—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup means for generating torque on steering wheel or input member, e.g. feedback
- B62D5/006—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup means for generating torque on steering wheel or input member, e.g. feedback power actuated
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/001—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup
- B62D5/005—Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup means for generating torque on steering wheel or input member, e.g. feedback
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K1/00—Details of the magnetic circuit
- H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
- H02K1/12—Stationary parts of the magnetic circuit
- H02K1/14—Stator cores with salient poles
- H02K1/146—Stator cores with salient poles consisting of a generally annular yoke with salient poles
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
- H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
- H02K21/22—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets rotating around the armatures, e.g. flywheel magnetos
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K21/00—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets
- H02K21/12—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets
- H02K21/24—Synchronous motors having permanent magnets; Synchronous generators having permanent magnets with stationary armatures and rotating magnets with magnets axially facing the armatures, e.g. hub-type cycle dynamos
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/12—Casings or enclosures characterised by the shape, form or construction thereof specially adapted for operating in liquid or gas
- H02K5/124—Sealing of shafts
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/15—Mounting arrangements for bearing-shields or end plates
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K5/00—Casings; Enclosures; Supports
- H02K5/04—Casings or enclosures characterised by the shape, form or construction thereof
- H02K5/16—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields
- H02K5/173—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings
- H02K5/1737—Means for supporting bearings, e.g. insulating supports or means for fitting bearings in the bearing-shields using bearings with rolling contact, e.g. ball bearings radially supporting the rotor around a fixed spindle; radially supporting the rotor directly
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/10—Structural association with clutches, brakes, gears, pulleys or mechanical starters
- H02K7/102—Structural association with clutches, brakes, gears, pulleys or mechanical starters with friction brakes
- H02K7/1021—Magnetically influenced friction brakes
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02K—DYNAMO-ELECTRIC MACHINES
- H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
- H02K7/14—Structural association with mechanical loads, e.g. with hand-held machine tools or fans
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Power Steering Mechanism (AREA)
Abstract
The invention relates to a steering device (1) comprising a rotatably mounted steering shaft (2) which can be coupled to a steering means (3), and an electric motor force feedback actuator (4) which has a stator (5) and a rotor (6) which can be rotated relative to the stator (5) and is connected to the steering shaft (2) in a torque-transmitting manner, wherein the stator (5) has a plurality of stator teeth (9) which protrude from a stator yoke (8) and each of the stator teeth (9) is wound around by at least one energizable stator winding (7), and wherein the magnetorheological brake (10) has an electromagnet (36) and has a magnetorheological material (13) on which the magnetic field of the electromagnet (36) can act, wherein the magnetorheological brake (10) is connected to the steering shaft (2) in a torque-transmitting manner, wherein the magnet coil (11) of the magnetorheological brake (10) is arranged in the stator yoke (8) and/or the stator yoke (8) of the electric motor actuator (4).
Description
Technical Field
The invention relates to a steering device comprising a rotatably mounted steering shaft which can be coupled to a steering means, and an electric motor force feedback actuator having a stator and a rotor which can rotate relative to the stator and is connected to the steering shaft in a torque-transmitting manner, wherein the stator has a plurality of stator teeth which protrude from a stator yoke and each of which is wound around by at least one energizable stator winding, and a magnetorheological brake having an electromagnet which can be energized by a magnet coil and on which the magnetic field of the electromagnet can act, wherein the magnetorheological brake is connected to the steering shaft in a torque-transmitting manner.
Background
Electric power steering devices are used in motor vehicles, among other applications, to receive a direction request from a driver and to convert the direction request into corresponding movements of one or more road-side wheels. In contrast to purely mechanical steering systems, electric steering systems distinguish between electric power-assisted steering systems and all-electric steering systems, so-called steer-by-wire steering systems. In particular, these steer-by-wire steering devices have the advantage that the operating unit can be positioned relatively freely in the vehicle independently of the mechanical connection part, which improves the accident behaviour due to the absence of a steering column, in addition to saving costs, for example, in distinguishing right-hand from left-hand vehicles. Furthermore, the operating unit can be brought into a stowed position, which can also be used, for example, with fully automatic steering.
Steer-by-wire steering systems within the meaning of the present invention are understood to mean steering systems which essentially comprise so-called Hand Wheel Actuators (HWA), actuator systems, for example around a commanded vehicle steering wheel, and Road Wheel Actuators (RWA), i.e. actuators acting on steering mechanisms connected to the wheels of the vehicle. In this case, the turn signal is transmitted from the HWA to the RWA by wire.
In order to produce a realistic driving experience, it is also known in the prior art to record parameters such as vehicle speed, steering angle, lateral acceleration, tie rod force, etc. from the actual current driving situation, or to calculate these parameters in a simulation and form a feedback signal from these parameters, which is fed into the force feedback actuator. A force feedback actuator is integrated into the input unit and has an actuator unit comprising an actuator acting as a manual torque actuator or a steering wheel actuator and which couples a feedback torque corresponding at least in part to the actual reaction torque into the steering wheel via the steering shaft in accordance with a feedback signal. Partial feedback torque is particularly useful when other possible controllable components, such as springs or brakes, provide additional feedback torque. The term feedback torque refers to both directions of action, i.e. the feedback actuator may be rotated by the driver as an adjustable load. This force feedback system gives the driver the impression of a real driving situation, just like conventional steering, which contributes to an intuitive response.
A steer-by-wire steering system with an input unit is known from DE 102008036730 A1, which has an actuator unit driven by an electric motor. The electric motor may be controlled by an electronic control unit which adjusts the motor current in dependence on measured values which characterize the respective driving situation. The motor shaft is directly coupled to the steering shaft such that the motor torque is the same as the manual torque coupled to the steering shaft. The electric motor is flange-connected to the housing unit in an axial direction with respect to the longitudinal axis, and the motor shaft is connected to a steering shaft mounted in the housing unit via a coupling. An actuator unit having a similar structure is shown in EP 2414211 B1. In the embodiment described therein, the steering shaft itself forms the motor shaft of the electric motor, so that a more compact design can be achieved.
Against this background, it is also known to provide an electric motor driven force feedback actuator with a transmission for improved adjustment of speed and torque. For example, an electric motor having a worm drive at the end of a steering column is known, which is connected to a steering wheel by means of a shaft. An example of this embodiment can be found in DE102018101528B 4. With these transmissions, relatively high transmission ratios and thus high torques can be achieved or maintained, but relatively large installation space requirements and angled designs are often disadvantageous. Furthermore, such force feedback actuators coupled with worm drives typically have to be greatly optimized with respect to friction (typically too high) and friction uniformity (typically too non-uniform) in terms of precision and material selection.
In addition to worm drives, it is also known to connect the electric motor of the force feedback actuator with a planetary transmission at the end of the steering column, as described for example in CN 215706606U. However, in the case of a planetary transmission, it is generally only possible to achieve moderate gear ratios and thus moderate torques in one stage. The use of friction or lost torque for force feedback requires additional effort and friction means.
In principle, directly driven force feedback actuators are also known, which are sometimes also referred to as direct drives. Examples of such designs can be found in CN112644580B or DE102018101528B 4. In principle, such a direct drive force feedback actuator requires a telescopic steering shaft at the distal end of the steering column, which is associated with cost and space requirements. Steering columns with direct drive force feedback actuators near the steering wheel are disclosed in EP3960583A1 and EP3476692B1, for example.
In order to achieve the truest steering feel in such steer-by-wire systems, it is also known to arrange a magnetorheological brake in the torque flow of the steering device to increase the resistance modulus. In combination, this makes it possible to achieve a higher total restoring torque with lower energy consumption in the same installation space. However, this combination is still relatively large and expensive to produce.
Disclosure of Invention
In view of this prior art, it is now an object of the present invention to provide a steering device for a motor vehicle which at least reduces the problems and disadvantages known from the prior art.
The object is achieved by a steering device comprising a rotatably mounted steering shaft which can be coupled to a steering means, and an electric motor force feedback actuator having a stator and a rotor which can rotate relative to the stator and is connected to the steering shaft in a torque-transmitting manner, wherein the stator has a plurality of stator teeth which protrude from a stator yoke and each of which is wound around by at least one energizable stator winding, and a magnetorheological brake having an electromagnet and having a magnetorheological material on which a magnetic field of the electromagnet can act, wherein the magnetorheological brake is connected to the steering shaft in a torque-transmitting manner, wherein the magnet coils of the magnetorheological brake are arranged in and/or on the stator yoke of the electric motor force feedback actuator.
This has the advantage that the stator is used for both the stator windings and for holding the magnet coils, thus reducing both weight and assembly effort. The stator of the electric motor force feedback actuator and the winding carrier of the magnet coils are thus designed as a single piece. The elimination of the mounting interface may also increase rigidity by using a one-piece component for the stator windings and magnet coils.
This also allows the stator to be made more compact, since a part of its material, in particular in the so-called "back connection", carries the fields of the two winding systems, namely the field of the stator windings and the field of the magnet coils. Thus, less overall material may be used, which may contribute to a corresponding weight saving.
Compact steering devices can be used not only far from the steering wheel but also close to the steering wheel due to their low weight.
Magnetorheological brakes may be designed as powder brakes based on well known effects such as the agglomeration of iron powder under the influence of a magnetic field or the formation of lines along a field line. These wires or blocks create braking forces or braking torques by magnetic adhesion between moving iron parts and stationary iron parts. When the magnetic field is deactivated, the braking effect will decrease as expected, on the one hand because small particles, typically 10 to 100 μm, then start to segregate, and on the other hand because particles are displaced from the sheared area into the adjacent stationary area. There is a magnetic field gradient in the quiescent zone such that when the brakes are activated, particles migrate from the quiescent zone back to the shear zone. The magnetorheological powder is surrounded by air or gas, and the magnetorheological powder can be easily compacted and has a low viscosity.
Alternatively, the medium may be a liquid, and particularly preferably a magnetorheological liquid. Magnetorheological fluids have the property that the magnetorheological fluid can change its viscosity by several orders of magnitude depending on the magnetic field passing through the magnetorheological fluid. The term "magnetorheological fluid" (MRF) refers to a liquid that reacts to a magnetic field in a manner similar to a ferrofluid, but unlike a ferrofluid, a magnetorheological fluid solidifies. For example, magnetorheological fluids include suspensions of micron-sized magnetic particles one to three orders of magnitude larger than the particles of the ferrofluid. When a magnetic field is applied, relatively large particles of magnetorheological fluid form chains. This increases the viscosity of the MRF and may even cure the MRF if insufficient compressive force is applied to break the chain.
According to an advantageous embodiment of the invention, it may be provided that the electric motor force feedback actuator is configured as an axial flux machine, wherein the stator teeth protrude from the stator yoke in the axial direction. The advantage of this design is that the axial flux machine enables a particularly compact axial steering device.
Against this background, it is particularly preferred that the magnet coils of the magnetorheological brake are arranged in the axial direction on the side of the stator yoke facing away from the stator teeth, which enables a particularly compact design and a particularly magnetically efficient stator structure.
According to a further preferred development of the invention, it can also be provided that the rotor is of disk-like design and is connected in a rotationally fixed manner to a pot-shaped outer sleeve, wherein the stator is accommodated in the pot-shaped outer sleeve. This creates an enclosure that holds the active component and the magnetorheological medium and also protects the active component and the magnetorheological medium from dust intrusion. Modern steering wheels with a large number of control elements in the centre already accommodate a "bottom" of the can-like design, so it is interesting to add only the side walls of the can.
Furthermore, according to a likewise advantageous embodiment of the invention, it may be provided that a first circumferential seal is arranged between the stator and the rotor and/or between the stator and the outer sleeve, and that a second circumferential seal is arranged between the outer sleeve and the cylindrical section extending axially from the stator yoke, such that a receiving space for the magnetorheological material is defined within the outer sleeve. The advantageous effect of this design is based on the fact that a relatively high degree of system integration of the magnetorheological brake and the force feedback actuator can be achieved, resulting in a particularly compact design of the steering device.
According to a further particularly preferred embodiment of the invention, it may be provided that an annular disk-shaped closing member is arranged axially between the second seal and the magnet coil, which closing member rests against the magnet coil. In particular, this makes it possible to achieve an orientation of the magnetic flux and an advantageous steering by means of the electromagnet. Thus, the annular closing member is made of a magnetic field conducting material.
According to a preferred embodiment of the invention, the stator teeth may protrude from the stator yoke in a radial direction. This allows the electric motor force feedback actuator to be configured as both a radial flux type machine and a transverse flux type machine.
Furthermore, the invention may be further developed such that the electric motor force feedback actuator is configured as a radial flux type machine or a transverse flux type machine, wherein the stator teeth protrude from the stator yoke in a radial direction. This means that radial flux type machines or transverse flux type machines can be basically designed as inner or outer rotors.
In a likewise preferred embodiment variant of the invention, it may also be provided that the electric motor force feedback actuator is configured as an external rotor, wherein the stator teeth protrude radially outwards from the stator yoke, which may provide particular manufacturing advantages. An external rotor motor designed in this way allows a radially further outward shear gap and high torque development and a good fit with the pot-like design of the steering wheel rotor. In addition, this design allows for simple winding techniques, since the teeth are accessible from the outside.
It may also be advantageous to develop the invention further such that the stator yoke has a cylindrical annular groove which is formed radially below the stator teeth and in which the magnet coils are accommodated, which may result in a particularly compact structure of the stator.
According to a further preferred embodiment of the subject matter of the invention, it may be provided that the rotor has a radially inner hollow cylinder and a radially outer hollow cylinder extending coaxially with the radially inner hollow cylinder, wherein the radially inner hollow cylinder is connected to the radially outer hollow cylinder via an annular disc and the inner hollow cylinder and the outer hollow cylinder cover the stator in the axial direction. This allows a good support of the rotor and also protects the components inside the rotor from external mechanical influences.
Finally, the invention can also be advantageously implemented such that the stator is formed of solid material without being laminated. This has the advantage that a stator made of electrical steel sheet may not be used, which may significantly reduce the manufacturing costs of the stator. This can also be aided by the fact that the winding heads or the additional components on the edge protection can be omitted compared to a conventional stator made of electrical steel sheet.
In particular in the field of steering applications, electric motor force feedback actuators exhibit almost the same force density and low losses compared to conventional stators made of electrical steel sheet. Furthermore, the stator has a more compact one-piece design compared to conventional stators made from electrical steel sheets. The unitary stator also allows for increased heat dissipation from the windings compared to conventional stators made from electrical steel, which may help to improve efficiency and higher thermal operational reliability. In addition, the magnetic properties of the stator are improved compared to electrical steel stacks, as there are no metal plate joints or non-magnetic metal plate laminations that would impair the magnetic properties.
The stator may particularly preferably be made of pure iron. Within the meaning of the present application, pure iron is an iron material having a purity content of more than 75 wt.% Fe, preferably more than 85 wt.% Fe, most preferably more than 95 wt.% Fe. The stator has a high saturation flux density (=power density) and can be manufactured cheaply because of the pure iron structure rather than the powder metallurgical structure, i.e. with residual porosity and suboptimal magnetic properties.
The use of steering devices in HWA (hand wheel actuator) of steer-by-wire systems is particularly preferred. Most preferably, the steering device is used in a HWA (hand wheel actuator) of a steer-by-wire system, wherein the electric motor force feedback actuator is arranged in the HWA close to the electric motor force feedback actuator of the steering wheel.
The steering shaft may be connected to the steering device in a rotationally fixed manner. The steering device can preferably be designed as a steering wheel. In principle, the steering device can also be designed as a steering bracket.
In connection with steering devices, it is particularly advantageous if the electric motor force feedback actuator has a speed of less than 300rpm during operation. It has also proved to be advantageous if the number of stator teeth is selected between 10 and 50, whereby the preferred torque for the steering device can be provided by the electric motor force feedback actuator.
It is further preferred that the electric motor force feedback actuator acts on the steering shaft without the interposition of a transmission. However, the steering system may also have a transmission. Specifically, the transmission has an input shaft and an output shaft, wherein the electric motor force feedback actuator is arranged on the input side and the steering shaft is arranged on the output side. Specifically, a power transmission path for transmitting engine torque extends between the rotor and the steering shaft via the transmission. The rotor is preferably arranged coaxially with the steering shaft.
The electric motor force feedback actuator and the transmission may advantageously form a structural unit, which may also be used as an electric motor driver or as a load unit. The electric motor force feedback actuator may be designed as an axial flux type motor or as a radial flux type motor. It is also possible to design the motor as a radial flux motor, for example as an inner rotor or an outer rotor. If the electric motor is designed as an axial flux type motor, the electric motor may be designed as a simple disc rotor in either an I-type configuration or an H-type configuration. Due to the axially compact design, an axial flux type motor may be preferred for the present invention.
The electric motor force feedback actuator may be housed in a motor housing. The transmission may also be accommodated in a transmission housing. Preferably, the motor housing and the gear housing are at least partially, preferably completely, formed as one piece and thus form a structural unit.
According to an advantageous embodiment of the invention, it can be provided that the transmission has a transmission ratio of 3 to 40. This also allows the electric motor to be designed smaller, which also has advantages in terms of reducing the collision mass in the event of an accident. In addition, eddy current losses of the electric motor force feedback motor can be kept low.
According to an advantageous embodiment of the invention, it may be provided that the electric motor force feedback actuator is configured as an electric radial flux motor having a cylindrical annular stator yoke and stator teeth protruding in a radial direction. According to a further preferred development of the invention, it can also alternatively be provided that the electric motor force feedback actuator is configured as an electric axial flux motor with a disk-shaped stator yoke and stator teeth protruding in the axial direction.
Preferably, the stator teeth of the electric motor force feedback actuator configured as an electric radial flux motor have rounded portions at their axial ends, which enables a simplified and safe winding together of the stator teeth with the stator windings, since the risk of damaging the stator windings, in particular the insulation of the stator windings, can be reduced by sharp edges avoided during the winding process. The radius projects outwardly and extends from one long side of a stator tooth to the other long side of the same stator tooth. Preferably, the radius is semi-circular.
In particular in the case of radial flux type motors, it may be advantageous to provide design measures on the stator to prevent torque ripple from occurring during operation. For example, due to the magnetic force acting on the permanent magnet synchronous motor, a significant cogging occurs when the rotor is manually rotated in the power-off state. However, a similar effect that occurs when the motor is energized and under load is more problematic for the operating characteristics of such synchronous motors, and is referred to in this context as load ripple, torque ripple, or torque ripple. If the number of poles is high enough, the load ripple is hardly noticeable when the motor is idling (when no torque or only low torque is produced). However, when the engine is operated with a high torque reduction, the load pulsation can be clearly noted as periodic torque fluctuations. The torque ripple generally follows a sinusoidal oscillation, which corresponds to higher harmonics of the torque variation occurring at the pole pairs.
The preferred method is to reduce load ripple by tilting the poles of the rotor relative to the poles of the stator. In the case of a permanent magnet synchronous motor, the poles formed on the stator may be arranged obliquely with respect to the rotation axis of the rotor. This inclination means that the entire cross-sectional areas of the poles do not face each other at any time, which results in a reduction of the maximum torque on the one hand and also has a balancing effect with respect to load pulsations on the other hand.
It is therefore particularly preferred that the stator teeth have a stagger along their axial extent, i.e. are arranged inclined at an angle relative to the rotational axis of the rotor. Such staggering may be linear or V-shaped along the axial extent of the stator teeth.
Furthermore, according to a likewise advantageous embodiment of the invention, it can be provided that the electric motor force feedback actuator, which is configured as an electric radial flux motor, is designed as an external rotor with a cylindrical annular stator yoke and stator teeth protruding outwards in the radial direction. The advantageous effect of this design is based on the fact that the external rotor can be wound particularly easily and thus cost effectively. Furthermore, machining, for example by milling, is significantly easier, faster and thus more cost-effective for a stator for an outer rotor than for an inner rotor.
According to a further particularly preferred embodiment of the invention, it may be provided that the stator teeth each have at their free distal end a tooth overhang for fixing the stator winding at least partially, preferably completely, circumferentially, which may also facilitate simple and safe winding of the stator teeth, since slipping of the winding from the stator teeth may be prevented by the tooth overhang. This benefit has been provided by the part circumferential overhang.
It is further preferred that the stator teeth have a radius formed at the transition between the tooth walls against which the windings rest, which may also help to optimise the windings or to protect the windings and wire insulation from damage by the edges.
The invention can furthermore be developed such that at least one bearing seat for a rolling bearing or a raceway for a rolling bearing is provided on the stator, wherein the rotor is rotatably mounted relative to the stator via the rolling bearing. The advantage of this design is that the increase in system integration allows a steering device which is particularly compact, has smaller tolerances and can be produced cost-effectively.
In a further preferred embodiment variant of the invention, it can also be provided that the stator has at least one opening for the passage of at least one stator winding through the stator yoke. This makes it possible to achieve electrical contacting of the windings or interconnection of the windings to be carried out mechanically in the radially inner installation space or in the axially adjacent installation space.
The manufacturing of the stator of the electric motor force feedback actuator of the steering device may comprise the steps of:
Providing a blank formed from pure iron,
-Forming the stator from the blank by machining
Milling and drilling have proven to be particularly suitable as machining processes in connection with the invention. In particular, the stator teeth and/or receptacles for the magnet coils may be formed by milling, preferably using a contour milling cutter for the winding region with overhanging portions.
Alternatively, the stator of the electric motor force feedback actuator of the steering device may be manufactured using a casting process, which then comprises, for example, the steps of:
-providing a mould to form a stator
-Filling the mould with pure iron
-Removing the mould and removing the stator
Preferably, the pure iron in flowable form is filled into a casting mold and subsequently solidified in the casting mold.
In principle, the stator will also be generated using an additive manufacturing process, which then may for example comprise the steps of:
-providing an additive manufacturing device,
Providing a data set representing the geometry of the stator,
Reading the data set into a manufacturing device,
Adaptively manufacturing a stator by means of a layer-by-layer deposited pure iron by means of a manufacturing device from a dataset representing the geometry of the stator
This additive manufacturing process differs significantly from conventional subtractive manufacturing methods. For example, in additive manufacturing, rather than milling a workpiece out of a solid block as is common in grinding processes, components are built layer by layer from materials or raw materials that can be used as starting materials, in particular as fine powders. Lasers, such as CO2 lasers, nd: YAG lasers or fiber lasers or even electron beam sources are commonly used for machining, such as melting raw materials, in particular in powder form.
Drawings
The invention is explained in more detail below with reference to the drawings without limiting the general concept of the invention.
In the drawings:
Figure 1 shows in a schematic block diagram a motor vehicle with a steer-by-wire system,
Figure 2 shows in a schematic view a steering device with a steering shaft and an electric motor force feedback actuator,
Figure 3 shows a first embodiment of the steering device in a perspective axial section,
Figure 4 shows in a cut-away perspective axial section the stator of the steering device in figure 4,
Figure 5 shows a second embodiment of the steering device in a perspective axial section,
Fig. 6 shows the stator of the steering device in fig. 5 in a sectioned perspective axial section.
Detailed Description
Fig. 1 shows a steering device 1 for use in a steer-by-wire system 34 of a motor vehicle 35. The electric steering signal generated by the steering device 1 is transmitted to the RWA33 (road wheel actuator), which then converts the steering signal into a corresponding position of the vehicle wheels.
As can be seen from fig. 2, the steering device 1 comprises a rotatably mounted steering shaft 2, which may be coupled to a steering means 3, and an electric motor force feedback actuator 4 having a stator 5 and a rotor 6, which is rotatable relative to the stator 5 and is connected to the steering shaft 2 in a torque-transmitting manner. A magnetorheological brake 10 is also arranged in the torque flow, by means of which an increase in the modulus of resistance to the steering movement of the user can be achieved. This is explained in more detail using the following figures.
Fig. 3 shows a first embodiment of a steering device 1 comprising a rotatably mounted steering shaft 2, which may be coupled to a steering means 3, and an electric motor force feedback actuator 4 having a stator 5 and a rotor 6, which is rotatable relative to the stator 5 and is connected to the steering shaft 2 in a torque-transmitting manner. The stator 5 has a plurality of stator teeth 9 protruding from a stator yoke 8, and each of the stator teeth 9 is wound around by at least one energizable stator winding 7.
Furthermore, the steering device 1 has a magnetorheological brake 10 with an electromagnet 36, which can be energized via the magnet coil 11, and with a magnetorheological material 13, on which the magnetic field of the electromagnet 36 can act. For example, by varying the magnetic field generated by the electromagnet 36, the viscosity of the magnetorheological material and thus the braking effectiveness of the brake 10 may be adjusted. As with the rotor 6, the magnetorheological brake 10 is also connected to the steering shaft 2 in a torque-transmitting manner.
The magnet coils 11 of the magnetorheological brake 10 are arranged in or on the stator yoke 8 of the electric motor force feedback actuator 4. For this purpose, a coil holder 32, which is formed as an annular groove, is provided in the stator yoke 8. The magnet coils 11 are arranged as radially inward as possible, which may contribute to low reluctance.
The electric motor force feedback actuator 4 of fig. 3 is configured as an axial flux machine, wherein the stator teeth 9 protrude in an axial direction from the stator yoke 8. The rotor 6 is disc-shaped and is connected in a rotationally fixed manner to a pot outer sleeve 12, wherein the stator 5 is accommodated within the pot outer sleeve 12. Rotor magnets 28 are arranged in the disc rotor 6. In the example shown, the connection between the rotor 6 and the outer sleeve 12 is achieved by a threaded connection. The rotor 6 is mounted with respect to the stator 5 by means of rolling bearings 23.
A first circumferential seal 14 is arranged between the stator 5 and the outer sleeve 12, and a second circumferential seal 16 is arranged between the outer sleeve 12 and a cylindrical section 15 extending axially from the stator yoke 8, such that a receiving space for the magnetorheological material 13 is defined within the outer sleeve 12. An annular disc-shaped closing part 17 is arranged axially between the second seal 16 and the magnet coil 11 and rests against the magnet coil 11. The closing member 17 may have in its radially outer region a surface structure 27 directed towards the outer sleeve 12, so that a particularly good braking effect is achieved in the gap between the radially extending surface structure 27 and the outer sleeve 12 in this region cooperating with the magnetorheological material 13.
For filling or discharging the magnetorheological material, a filling opening 29 is provided in the outer sleeve 12, which can be closed, for example, by a screw.
Furthermore, a rolling bearing 22 is arranged on the cylindrical section 15, which rolling bearing supports the cylindrical section 15 which is rotationally fixed relative to the rotatable outer sleeve 12. An axially extending threaded bore 26 is provided on the end face of the cylindrical section 15, by means of which the steering device can be fastened to, for example, a telescopic extension.
Both the winding end 24 of the stator winding 7 and the coil end 25 of the magnet coil 11 are guided radially inwards into the hollow cylindrical stator 5. For this purpose, corresponding feed-through openings 30, 31 are provided in the stator, which can also be seen clearly in fig. 4. Additional cable connections may also be routed through the hollow cylindrical stator 5, for example for connection to the steering device 3.
Fig. 5 shows a further embodiment variant of the steering device 1, in which the electric motor force feedback actuator 4 is configured as a radial flux machine, in which the stator teeth 9 protrude from the stator yoke 8 in a radial direction. In the embodiment shown, the electric motor force feedback actuator 4 is configured as an external rotor, wherein the stator teeth 9 protrude radially outwards from the stator yoke 8.
The stator yoke 8 has a cylindrical annular groove 18 formed radially below the stator teeth 9, and in which the magnet coils 11 are received. Thus, in the illustrated embodiment, the magnet coils 11 are offset laterally such that the closed stator 5 provides an effective outer cylindrical surface for the gap containing the magnetorheological material 13, at which surface a high braking torque is generated.
The rotor 6 has a radially inner hollow cylindrical member 19 and a radially outer hollow cylindrical member 20 extending coaxially with the radially inner hollow cylindrical member, wherein the radially inner hollow cylindrical member 19 is connected to the radially outer hollow cylindrical member 20 via an annular disk 21, and the inner hollow cylindrical member 19 and the outer hollow cylindrical member 20 axially cover the stator 5.
Common to all stators 5 shown in the figures is that all stators are formed of solid material and are not laminated.
The invention is not limited to the embodiments shown in the drawings. Accordingly, the above description should not be taken as limiting, but rather as illustrative. The appended claims should be construed to mean that the recited features are present in at least one embodiment of the present invention. This does not preclude the presence of other features. Where the claims and the above description define "first" and "second" features, this naming is used to distinguish between two features of the same type, and does not define a priority order.
List of reference numerals
1. Steering device
2. Steering shaft
3. Steering device
4. Force feedback actuator
5. Stator
6. Rotor
7. Stator winding
8. Stator yoke
9. Stator teeth
10. Magnetorheological brake
11. Magnet coil
12. Outer sleeve
13. Magnetorheological materials
14. Sealing element
15. Cylindrical section
16. Sealing element
17. Closure member
18. Groove
19. Hollow cylindrical member
20. Hollow cylindrical member
21. Annular disk
22. Rolling bearing
23. Rolling bearing
24. Winding end
25. Coil end
26. Threaded hole
27. Surface structure
28. Rotor magnet
29. Filling the opening
30. Feed-through opening
31. Feed-through opening
32. Coil holder
33. Walking wheel actuator
34. Steer-by-wire system
35. Motor vehicle
36. Electromagnet
Claims (10)
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE102023108159.4 | 2023-03-30 | ||
| DE102023108159.4A DE102023108159B4 (en) | 2023-03-30 | 2023-03-30 | Steering device |
| PCT/DE2024/100195 WO2024199573A1 (en) | 2023-03-30 | 2024-03-12 | Steering device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN121039011A true CN121039011A (en) | 2025-11-28 |
Family
ID=90457911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202480020878.3A Pending CN121039011A (en) | 2023-03-30 | 2024-03-12 | Steering mechanism |
Country Status (4)
| Country | Link |
|---|---|
| KR (1) | KR20250165419A (en) |
| CN (1) | CN121039011A (en) |
| DE (1) | DE102023108159B4 (en) |
| WO (1) | WO2024199573A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102023123746A1 (en) * | 2023-09-04 | 2025-03-06 | Hangzhou Kingway Technology Co., Ltd. | Brake unit for force feedback system, force feedback system with brake unit and steering device with force feedback system |
| DE102024117436A1 (en) * | 2024-06-20 | 2025-12-24 | Inventus Engineering Gmbh | Method for filling a component |
| CN119636887B (en) * | 2025-02-19 | 2025-04-15 | 温州益能电器有限公司 | Direct-drive-by-wire steering wheel based on magnetic gear technology |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6854573B2 (en) * | 2001-10-25 | 2005-02-15 | Lord Corporation | Brake with field responsive material |
| DE10221241A1 (en) * | 2002-05-13 | 2003-11-27 | Kostal Leopold Gmbh & Co Kg | Steering device for a motor vehicle steered by a steer-by-wire device has a steering wheel, an electric drive and a device for generating a steering haptic device to act on the steering wheel |
| DE102008036730B4 (en) * | 2008-08-07 | 2019-05-16 | Ebm-Papst St. Georgen Gmbh & Co. Kg | Actuator unit for a motor vehicle steer-by-wire steering device |
| DE102009017054A1 (en) * | 2009-04-01 | 2010-10-07 | Leopold Kostal Gmbh & Co. Kg | Steering column for motor vehicles |
| DE102015226099A1 (en) * | 2015-12-18 | 2017-06-22 | Robert Bosch Gmbh | Electric machine for a steering drive and a steering drive system |
| JP6767217B2 (en) * | 2016-09-16 | 2020-10-14 | アルプスアルパイン株式会社 | Input device |
| IT201700121876A1 (en) * | 2017-10-26 | 2019-04-26 | Ferrari Spa | "STEER BY WIRE" ROAD VEHICLE SYSTEM AND PROVIDED WITH A TELESCOPIC SUPPORTING ELEMENT FOR THE STEERING WHEEL " |
| DE102018101528B4 (en) * | 2018-01-24 | 2019-12-12 | Thyssenkrupp Ag | Steering column for a motor vehicle |
| EP4275992A3 (en) * | 2020-08-28 | 2024-02-21 | Lotus Tech Innovation Centre GmbH | Steer-by-wire steering system having an off-axis steering system support column |
| CN112644580B (en) * | 2021-01-21 | 2022-03-01 | 东风汽车集团股份有限公司 | Wire-controlled steering column and wire-controlled steering control method |
| KR20230142484A (en) * | 2021-02-05 | 2023-10-11 | 로오드 코포레이션 | Active/semi-active wire-steering system and method |
| CN215706606U (en) * | 2021-06-22 | 2022-02-01 | 中国第一汽车股份有限公司 | Steering column of electric adjustment |
| DE102021209701A1 (en) * | 2021-09-03 | 2023-03-09 | Brose Fahrzeugteile SE & Co. Kommanditgesellschaft, Würzburg | Electromotive feedback drive for a steering system |
-
2023
- 2023-03-30 DE DE102023108159.4A patent/DE102023108159B4/en active Active
-
2024
- 2024-03-12 KR KR1020257035921A patent/KR20250165419A/en active Pending
- 2024-03-12 WO PCT/DE2024/100195 patent/WO2024199573A1/en not_active Ceased
- 2024-03-12 CN CN202480020878.3A patent/CN121039011A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| KR20250165419A (en) | 2025-11-25 |
| WO2024199573A1 (en) | 2024-10-03 |
| DE102023108159A1 (en) | 2024-10-02 |
| DE102023108159B4 (en) | 2025-08-07 |
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