Single-wheel regulator for steering system of motor vehicle, and steering system

Abstract

The invention relates to a single-wheel actuator (1) for a steering system, in particular a steer-by-wire system, of a motor vehicle, comprising: a single-wheel actuator (1) connected to a joint head (18) or a universal joint (19) that can be coupled to a wheel carrier (16); comprising an electric motor (13) and a conversion transmission (11) coupled to the electric motor (13) and is designed to perform an axial movement of the tappet (14) from a first position substantially arranged in the housing interior (12) to a second position substantially out of the housing (10); and a first anti-rotation device (22) arranged on the outer side of the housing (10) and a second anti-rotation device (24) arranged on the cross joint (19), or a first anti-rotation device (22) arranged on the outer side of the housing (10) and a third anti-rotation device (26) arranged in the housing (10), or a second anti-rotation device (24) arranged on the cross joint (19) and a third anti-rotation device (26) arranged in the housing (10).

Description

Field of the Invention

[0001] The present invention relates to a single-wheel regulator for a motor vehicle steering system.

[0002] Furthermore, the present invention also relates to a steering system for a motor vehicle. Background Art

[0003] In a conventional steering system, the required steering angle is transmitted from the steering wheel to the two front wheels through a mechanical connection. The steering torque is amplified by a servo drive (Servogetriebe) to enable easy steering.

[0004] In a future steer-by-wire steering system, the mechanical connection between the steering wheel and the steering wheels is eliminated. The steering angle set on the steering wheel is detected by a sensor and transmitted electronically to the steering actuator, which then adjusts the front wheels accordingly.

[0005] The steering system can be centrally acting, i.e., the steering actuator simultaneously controls both wheels. Generally, the translational movement of the rack is transmitted to the tie rods (Spurstangen), which pivot the wheels. However, the maximum steering angle on the front wheels is kinematically limited.

[0006] For a decentralized steering system, each steering wheel is assigned its own steering actuator, so that each wheel can be individually controlled. This can increase the maximum steering angle. Since the central steering actuator at the vehicle center is eliminated, there are spatial layout advantages for vehicle manufacturers. In addition, the decentralized steering system can also implement new functions, such as a parking brake function by reversing the wheels.

[0007] For decentralized single-wheel regulators, for example, ball screw drives (Kugelgewindetrieb) are known. Among them, the translational movement of the ball screw (Kugelgewindestange) is converted into a rotational movement for pivoting the wheel.

[0008] DE102020213664A1 discloses an electric single-wheel regulator for a motor vehicle, which has a double-wheel bracket composed of an axle bracket and a pivot bracket, wherein the pivot bracket is rotatably supported within the axle bracket, and the electric single-wheel regulator further has a motor, and the motor pivots the pivot bracket through a transmission, and the motor is arranged on the axle bracket.

[0009] To prevent the ball screw from twisting, an anti-twist device needs to be provided. Conventionally, the anti-twist device for an axially movable rod is arranged within the single-wheel regulator and supported on the vehicle body through the housing. The anti-twist device of the entire single-wheel regulator is also the connection structure between the single-wheel regulator and the vehicle body.

[0010] However, these solutions cannot provide optimal anti-twist effect over the entire length of the single-wheel regulator and the push rod. Summary of the Invention

[0011] Therefore, an object of the present invention is to provide a single-wheel regulator that can provide an optimal anti-twist effect over the entire length of the single-wheel regulator and the push rod.

[0012] The above object is achieved by the technical solutions of claims 1 and 11.

[0013] The present invention provides a single-wheel regulator for a steering system of a motor vehicle, in particular a steer-by-wire system.

[0014] The single-wheel regulator includes a housing and a push rod arranged at least sectionally in the inner cavity of the housing. The push rod is supported in the housing at a first axial end section and is connected to a joint head (Gelenkkopf) that can be coupled to a wheel carrier at a second axial end section arranged opposite to the first axial end section.

[0015] In addition, the single-wheel regulator further includes a drive unit having a motor and a conversion transmission (Wandlungsgetriebe) coupled to the motor. The drive unit is configured to perform an axial movement of the push rod from a first position substantially arranged in the inner cavity of the housing to a second position substantially exiting from the housing.

[0016] The single-wheel regulator further includes: a first anti-twist device arranged on the outer side surface of the housing and a second anti-twist device arranged on a cross universal joint (Kreuzgelenk); or a first anti-twist device arranged on the outer side surface of the housing and a third anti-twist device arranged in the housing; or a second anti-twist device arranged on the cross universal joint and a third anti-twist device arranged in the housing.

[0017] In addition, the present invention further provides a steering system for a motor vehicle, in particular a steer-by-wire system, which has a plurality of single-wheel regulators according to the present invention. The single-wheel regulator is configured to steer a wheel connected to the corresponding single-wheel regulator.

[0018] The idea of the present invention is to provide more effective anti-twist by providing at least one first anti-twist device configured to support the torque applied to the push rod by the drive unit on a wheel carrier that can be connected to the first anti-twist device. Since the first anti-twist device is arranged in the area of the wheel carrier, the torque applied to the push rod is acted on or transmitted to this area. Therefore, the torque acting on the push rod can be advantageously and effectively supported.

[0019] Advantageous embodiments and improvements are derived from the dependent claims and the description with reference to the accompanying drawings.

[0020] According to a preferred refinement, the anti-twist device is configured to support the torque applied to the push rod by the drive unit on the wheel carrier and / or on the motor vehicle body.

[0021] Thus, for different designs of the single-wheel steering gear, that is, with a first anti-twist device arranged on the outer side of the housing and a second anti-twist device arranged on the cardan joint, or a first anti-twist device arranged on the outer side of the housing and a third anti-twist device arranged in the housing, or a second anti-twist device arranged on the cardan joint and a third anti-twist device arranged in the housing, an optimum arrangement or configuration of the anti-twist device can be set respectively.

[0022] According to another preferred refinement, the second anti-twist device has a first section of substantially annular configuration and a second section of substantially annular configuration surrounding the first section of substantially annular configuration, wherein the second section is rotatably supported relative to the first section.

[0023] The first section is fixed since it is fixedly connected to the push rod. The second section is rotatably supported relative to the first section such that the second section can rotate therewith when the wheel carrier moves in the direction of rotation.

[0024] According to another preferred refinement, the second section of substantially annular configuration surrounding the first section of substantially annular configuration is rotatably supported about an axis extending in the radial direction of the push rod. Thus, when the wheel rotates, the second section can rotate therewith substantially parallel to the steering angle (Einschlagwinkel).

[0025] According to another preferred refinement, the first anti-twist device is configured to radially support the push rod. Thus, this anti-twist device has the dual function of anti-twisting and supporting the push rod. Thereby, a separate radial bearing for the push rod can be advantageously dispensed with.

[0026] According to another preferred refinement, the first anti-twist device is configured to support the torque applied to the push rod by the drive unit on the vehicle body that can be connected to the first anti-twist device.

[0027] By providing the first anti-twist device, anti-twisting of the housing of the single-wheel regulator relative to the motor vehicle body can be advantageously achieved.

[0028] According to another preferred refinement, the second anti-twist device is arranged on the housing of the single-wheel regulator in the region between the first end face of the single-wheel regulator facing the wheel carrier and the second end face of the single-wheel regulator facing away from the wheel carrier.

[0029] Thus, the anti-torsion of the single-wheel adjuster is not achieved at the vehicle body side end of the single-wheel adjuster, but can be flexibly arranged throughout the entire length of the single-wheel adjuster.

[0030] According to another preferred improvement, the single-wheel adjuster has a suspension device at the second end face, which is configured to swingably suspend the single-wheel adjuster on the vehicle body, wherein the degrees of freedom of the swinging movement are defined by a first pivot axis arranged substantially perpendicular to the longitudinal axis of the push rod and a second pivot axis arranged substantially perpendicular to the longitudinal axis of the push rod.

[0031] According to another preferred improvement, the first pivot axis and the second pivot axis of the single-wheel adjuster are arranged adjacent to the electrical connection part of the drive unit.

[0032] The suspension device is configured to swingably suspend the single-wheel adjuster on the vehicle body, wherein the degrees of freedom of the swinging movement are defined by a first pivot axis arranged substantially perpendicular to the longitudinal axis of the push rod and a second pivot axis arranged substantially perpendicular to the longitudinal axis of the push rod. This design advantageously realizes the articulated suspension of the single-wheel adjuster, wherein the articulated structure (Gelenk, joint) is composed of two virtual axes (i.e., pivot axes), and these two axes are perpendicular to each other and substantially perpendicular to the push rod axis.

[0033] Therefore, the suspension device ensures the rotational degrees of freedom about these two axes. At the same time, these two axes also prevent the entire single-wheel adjuster from rotating about the push rod axis.

[0034] According to a preferred improvement, the first pivot axis is arranged substantially perpendicular to the second pivot axis. Thereby, the effective swinging ability of the single-wheel adjuster about the pivot axis aligned with the longitudinal axis of the push rod can be advantageously realized.

[0035] According to another preferred improvement, the first pivot axis and / or the second pivot axis intersect with the longitudinal axis of the push rod. Thus, the optimal alignment of the pivot axis relative to the longitudinal axis of the push rod is achieved.

[0036] According to another preferred improvement, the first pivot axis and the second pivot axis of the single-wheel adjuster are arranged adjacent to the electrical connection part of the drive unit, or arranged along the axial length of the motor.

[0037] This enables the electrical connection part of the drive unit to advantageously maintain a short length. In addition, the movement of the electrical cable can be reduced thereby, thus reducing wear.

[0038] The above design solutions and improvement solutions can be combined with each other arbitrarily.

[0039] Other possible design solutions, improvement solutions and implementation manners of the present invention also include combinations of features of the present invention that are not explicitly mentioned and are described in combination with the preceding or following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The drawings are used to assist in understanding the embodiments of the present invention. They show specific embodiments and are combined with the description to explain the principles and concepts of the present invention.

[0041] Other embodiments and many of the above advantages can also be obtained in combination with the drawings. The elements shown in the drawings are not necessarily drawn to scale.

[0042] Figure 1 Schematic diagram showing a single-wheel regulator for a steering system, in particular a steer-by-wire system, according to a first embodiment of the present invention;

[0043] Figure 2 Schematic diagram showing a vehicle body suspension device of a single-wheel regulator for a steering system, in particular a steer-by-wire system, according to a first embodiment of the present invention;

[0044] Figure 3 Schematic diagram showing a single-wheel regulator for a steering system, in particular a steer-by-wire system, according to a second embodiment of the present invention;

[0045] Figure 4 Schematic diagram showing a single-wheel regulator for a steering system, in particular a steer-by-wire system, according to a third embodiment of the present invention.

[0046] In the drawings, unless otherwise specified, the same reference numerals denote the same or functionally identical elements, components, or assemblies. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] Figure 1 Schematic diagram showing a single-wheel regulator for a steering system according to a first embodiment of the present invention.

[0048] The single-wheel regulator 1 includes a housing 10 and a push rod 14 arranged at least sectionally in the inner cavity 12 of the housing. The push rod is supported by a conversion transmission device 11 and is connected to a joint head 18 that can be coupled to a wheel bracket 16 at a second axial end section 14b of the push rod 14 that is oppositely arranged to a first axial end section 14a of the push rod 14 arranged in the housing 10.

[0049] In addition, the single-wheel regulator 1 includes a drive unit 20 that has a motor 13 and a conversion transmission device 11 coupled to the motor 13. The drive unit is configured to perform an axial movement of the push rod 14 from a first position substantially arranged in the inner cavity 12 of the housing to a second position substantially exiting from the housing 10.

[0050] The single-wheel regulator further includes a first anti-torsion device 22 arranged on the outer side surface of the housing 10 and a third anti-torsion device 26 arranged in the housing 10.

[0051] The anti-twist devices 22, 26 are also configured to support the torque applied to the push rod 14 by the drive unit 20 on the vehicle body of the motor vehicle.

[0052] The first anti-twist device 22 is configured to support the torque applied to the push rod 14 by the drive unit 20 on the vehicle body that can be connected to the first anti-twist device 22.

[0053] The first anti-twist device 22 is arranged on the housing 10 of the single-wheel regulator 1 in the region between the first end face 36 of the single-wheel regulator 1 facing the wheel carrier 16 and the second end face 38 of the single-wheel regulator 1 facing away from the wheel carrier 16.

[0054] Figure 2 The schematic diagram of the vehicle body suspension device of the single-wheel regulator for a steering system, in particular a steer-by-wire system, according to the first embodiment of the present invention is shown.

[0055] The single-wheel regulator 1 also has a suspension device 25 at the second end face 38, which is configured to swingably suspend the single-wheel regulator 1 on the vehicle body, wherein the degrees of freedom of the swinging movement are defined by a first pivot axis P1 arranged substantially perpendicular to the longitudinal axis L of the push rod 14 and a second pivot axis P2 arranged substantially perpendicular to the longitudinal axis L of the push rod 14.

[0056] The first pivot axis A1 is arranged substantially perpendicular to the second pivot axis A2. In addition, the first pivot axis A1 and / or the second pivot axis A2 intersect with the longitudinal axis L of the push rod 14.

[0057] The first pivot axis P1 and the second pivot axis P2 of the single-wheel regulator 1 are arranged adjacent to the connection part 34 of the electrical line of the drive unit 20 or along the axial length of the motor 13.

[0058] Figure 3 The schematic diagram of the single-wheel regulator for a steering system, in particular a steer-by-wire system, according to the second embodiment of the present invention is shown.

[0059] The single-wheel regulator 101 also includes a first anti-twist device 22 arranged on the outer side surface of the housing 10 and a second anti-twist device 24 arranged on the cross universal joint 19.

[0060] The anti-twist devices 22, 24 are configured to support the torque applied to the push rod 14 by the drive unit 20 on the wheel carrier 16 and the vehicle body of the motor vehicle.

[0061] The second anti-twist device 24 has a first section 24a with a substantially annular structure and a second section 24b with a substantially annular structure surrounding the first section 24a with a substantially annular structure. Among them, the second section 24b is rotatably supported relative to the first section 24a.

[0062] A second section 24b of a substantially annular structure that surrounds a first section 24a of the substantially annular structure is rotatably supported about an axis extending in the radial direction of the push rod 14. The second anti-torsion device 24 is also configured to radially support the push rod 14.

[0063] The single-wheel regulator 101 also has a suspension device 125 at the third axial end section 122, which is configured to swingably suspend the single-wheel regulator 101 on the vehicle body, wherein the degrees of freedom of the swinging movement are defined by a first pivot axis A1 arranged substantially perpendicular to the longitudinal axis of the push rod 14 and a second pivot axis A2 arranged substantially perpendicular to the longitudinal axis of the push rod 14.

[0064] Figure 4 Schematic view showing a single-wheel regulator for a steering system, in particular a steer-by-wire system, according to a third embodiment of the present invention.

[0065] The drive unit 20 includes a motor 213 arranged concentrically with the longitudinal axis of the push rod 14, and the motor has a hollow shaft for internally accommodating the push rod 14.

[0066] The single-wheel regulator 201 also has a suspension device 225 at the third axial end section 222, which is configured to swingably suspend the single-wheel regulator 201 on the vehicle body, wherein the degrees of freedom of the swinging movement are defined by a first pivot axis A1 arranged substantially perpendicular to the longitudinal axis of the push rod 14 and a second pivot axis A2 arranged substantially perpendicular to the longitudinal axis of the push rod 14.

[0067] The first pivot axis A1 and the second pivot axis A2 of the single-wheel regulator 201 are also arranged along the axial length of the motor 213.

[0068] A cardan joint 19 is provided at the wheel-side end of the push rod 14, which allows rotational movement in two directions perpendicular to the push rod axis. At the same time, the cardan joint constitutes an anti-torsion structure of the push rod 14 on the wheel carrier.

[0069] The motor is connected to a conversion transmission device 211 arranged concentrically with the longitudinal axis of the push rod 14, in particular a planetary roller screw drive The conversion transmission device 211 is configured to convert the rotational movement of the planetary roller screw drive generated by the motor 13 into a translational movement of the push rod 14 meshing with the planetary roller screw drive. Instead of the planetary roller screw drive, a ball screw drive may also be provided.

[0070] The motor 13 provides torque and steering angle and transmits both to the nut of the planetary roller screw drive. The nut is supported rotatably but essentially cannot be displaced axially. The nut transmits the rotational movement via a threaded push rod to an axially movable threaded rod, which is threaded in the circumferential direction. The push rod is secured against torsion at its interface with the wheel carrier 16.

[0071] The supporting torque is provided by the wheel bracket 16. Therefore, when the nut rotates, the push rod 14 generates an axial movement. The push rod 14 is driven out or retracted from the housing 10, thereby making the single-wheel adjuster 201 retractable.

[0072] By omitting the second push rod bearing, the overall length of the single wheel adjuster 201 is further shortened. The push rod 14 is supported directly by the planetary roller screw drive, which in turn is fixed to the vehicle body in an articulated and rotationally fixed manner via the housing 10 .

[0073] Therefore, it is reasonable to arrange the pivot axis close to the nut, especially under dynamic loads perpendicular to the push rod axis, so that the smallest possible bending moment can be introduced to the housing 10 via the planetary roller screw drive. The stop position of the wheel is achieved by the holding torque of the motor. Additional mechanical stop limits can be achieved at the motor end by a stop point fixed relative to the housing and / or a sleeve between the wheel carrier 16 and the motor.

Claims

1. A single-wheel adjuster (1; 101; 201) for a steering system of a motor vehicle, in particular a steer-by-wire system, the steering system having: a housing (10) and a push rod (14) arranged at least sectionally in the inner cavity (12) of the housing, the push rod being supported by a conversion transmission (11) and at a second axial end section (14b) of the push rod (14) arranged opposite a first axial end section (14a) of the push rod (14) arranged in the housing (10), being connected to a joint head (18) or a cardan joint (19) which can be coupled to a wheel carrier (16); a drive unit (20) which includes an electric motor (13) and a conversion transmission (11) coupled to the electric motor (13), the drive unit being configured to perform an axial movement of the push rod (14) from a first position arranged substantially in the inner cavity (12) of the housing to a second position substantially emerging from the housing (10); and a first anti-twist device (22) arranged on the outer side surface of the housing (10) and a second anti-twist device (24) arranged on the cardan joint (19), or a first anti-twist device (22) arranged on the outer side surface of the housing (10) and a third anti-twist device (26) arranged in the housing (10), or a second anti-twist device (24) arranged on the cardan joint (19) and a third anti-twist device (26) arranged in the housing (10).

2. The single-wheel regulator according to claim 1, wherein, The anti-twist devices (22, 24, 26) are configured to support the torque applied by the drive unit (20) to the push rod (14) on the wheel carrier (16) and / or the vehicle body of the motor vehicle.

3. The single-wheel regulator according to claim 1 or 2, wherein, The second anti-twist device (24) has a first section (24a) of substantially annular configuration and a second section (24b) of substantially annular configuration surrounding the first section (24a) of substantially annular configuration, wherein the second section (24b) is rotatably supported relative to the first section (24a).

4. The single-wheel adjuster according to claim 3, wherein, The second section (24b) of substantially annular configuration surrounding the first section (24a) of substantially annular configuration is rotatably supported about an axis extending in the radial direction of the push rod (14).

5. The single-wheel regulator according to any one of the preceding claims, wherein, The second anti-twist device (24) is configured to radially support the push rod (14).

6. The single-wheel regulator according to any one of the preceding claims, wherein, The first anti-twist device (22) is configured to support the torque applied by the drive unit (20) to the push rod (14) on the vehicle body which can be connected to the first anti-twist device (22).

7. The single-wheel adjuster according to claim 6, wherein, The first anti-twist device (22) is arranged on the housing (10) of the single-wheel adjuster (1) in a region between a first end face (36) of the single-wheel adjuster (1) facing the wheel carrier (16) and a second end face (38) of the single-wheel adjuster (1; 101; 201) facing away from the wheel carrier (16).

8. The single-wheel regulator according to claim 7, wherein, The single-wheel adjuster (1; 101; 201) has a suspension device at the second end face (38), which is configured to swingably suspend the single-wheel adjuster (1; 101; 201) on the vehicle body, wherein the degrees of freedom of the swinging movement are defined by a first pivot axis (P1) arranged substantially perpendicular to the longitudinal axis of the push rod (14) and a second pivot axis (P2) arranged substantially perpendicular to the longitudinal axis of the push rod (14).

9. The single-wheel adjuster according to claim 8, wherein, The first pivot axis (A1) is arranged substantially perpendicular to the second pivot axis (A2).

10. The single-wheel regulator according to claim 8 or 9, wherein, The first pivot axis (A1) and / or the second pivot axis (A2) intersects the longitudinal axis of the push rod (14).

11. The single-wheel adjuster according to any one of claims 8 to 10, wherein, The first pivot axis (P1) and the second pivot axis (P2) of the single-wheel adjuster (1; 101; 201) are arranged adjacent to the connection part of the electrical circuit of the drive unit (20), or are arranged along the axial length of the motor (13).

12. A steering system for a motor vehicle, in particular a steer-by-wire system, the steering system comprising a plurality of single-wheel adjusters (1; 101; 201) according to any one of claims 1 to 11, the single-wheel adjusters being configured to steer the wheels connected to the respective single-wheel adjusters (1; 101; 201).

Images