Rear wheel steering gear with locking function and vehicle

Abstract

The invention provides a rear wheel steering gear with a locking function and a vehicle. A shell of the rear wheel steering gear is used for containing a rotary input piece, a rotary output piece, a plurality of pairs of rolling pieces and a plurality of elastic assemblies. The rotary input part is used for receiving driving of the steering motor and is in transmission connection with the rotary output part. The rotary output part is in transmission connection with a tie rod of a rear wheel in the vehicle. The rotary input part comprises a plurality of axial protrusions, and the axial protrusions surround the rotary output part and are embedded in the rotary output part in the radial direction. The peripheral face of the rotary output piece comprises a plurality of side faces, a gap between each side face and the shell is used for containing a pair of rolling pieces, and every two adjacent pairs of rolling pieces are arranged on the two sides of the axial protrusion respectively. The elastic assembly is used for driving the two rolling pieces to be away from each other and locking the rotating output piece. The axial protrusions are used for driving the pair of rolling pieces to be close to each other and driving the rotating output piece to rotate. According to the rear wheel steering gear, by optimizing the internal structure, the torque bearing capacity of the rear wheel steering gear is improved so as to improve the reliability.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a rear wheel steering gear with a locking function and a vehicle. Background Art

[0002] The rear wheel steering gear is used to control the rear wheel steering of the vehicle to reduce the vehicle's center of mass side slip angle during the steering process, reduce the steady-state overshoot of the vehicle's yaw rate, and achieve smooth steering. Before and after the vehicle turns, the rear wheel steering gear needs to be used to limit the rear wheel steering to ensure normal driving of the vehicle. Summary of the invention

[0003] The present application provides a rear wheel steering gear with a locking function and a vehicle. By optimizing the internal structure of the rear wheel steering gear, the torque bearing capacity of the rear wheel steering gear is increased to improve reliability.

[0004] In the first aspect, the present application provides a rear wheel steering gear with a locking function, wherein the housing of the rear wheel steering gear is used to accommodate a rotating input member, a rotating output member, a plurality of pairs of rolling members and a plurality of elastic components, wherein the transmission end of a rotating input member is used to receive the drive of the steering motor of the vehicle, the coupling end of a rotating input member is used to drive the coupling end of a rotating output member, and the transmission end of a rotating output member is used to drive the tie rod of at least one rear wheel in the vehicle. The coupling end of one rotating input member includes a plurality of axial protrusions, the plurality of axial protrusions surround the coupling end of a rotating output member and are spaced apart, and a rotating output member and each axial protrusion are embedded in the radial direction of the rotating output member. The outer peripheral surface of the coupling end of a rotating output member includes a plurality of side surfaces, and the gap between each side surface and the housing is used to accommodate a pair of rolling members, and two pairs of rolling members adjacent to each other along the circumference of a rotating output member are respectively arranged on both sides of an axial protrusion, and the two rolling members in each pair of rolling members are spaced apart and arranged between the two axial protrusions. Each elastic component is used to drive two rolling elements in a pair of rolling elements to move away from each other and lock the rotation of a rotating output element during the process of a rotating input element stopping rotation, and each axial protrusion is used to drive a pair of rolling elements to move toward each other and drive the rotation of a rotating output element during the process of a rotating input element rotating.

[0005] The rear wheel steering gear provided by the present application is connected to the motor shaft of the steering motor of the vehicle through the transmission end of the rotating input member, and the coupling end of the rotating input member is embedded with the coupling end of the rotating output member along the radial direction of the rotating output member, so as to achieve the effect of the rotating input member connecting the motor shaft of the steering motor and the rotating output member. The rear wheel steering gear is able to transmit the drive of the steering motor to the rotating output member. The rear wheel steering gear of the present application is also connected to the tie rod of at least one rear wheel of the vehicle through the transmission end of the rotating output member, so as to achieve the rotating output member driving the tie rod to move axially along the tie rod to drive at least one rear wheel of the vehicle to change the direction. The rear wheel steering gear of the present application is able to connect the steering motor and the tie rod of at least one rear wheel.

[0006] The rear wheel steering device provided by the present application also achieves the effect of locking the rotation of the rotation output member during the process of the rotation input member stopping rotation, and driving the rotation output member to rotate synchronously during the rotation of the rotation input member, through the cooperation of the coupling end of the rotation input member, the coupling end of the rotation output member, multiple pairs of rolling members and multiple elastic components. Among them, the coupling end of the rotation input member includes multiple axial protrusions, and the multiple axial protrusions and multiple pairs of rolling members alternately surround the outer peripheral surface of the coupling end of the rotation output member. In the process of the rotation input member stopping rotation, the multiple pairs of rolling members respectively receive the drive of each elastic component to move away from each other and abut against the same side of the rotation output member, so as to respectively limit the rotation of the rotation output member in the circumferential direction clockwise or counterclockwise. When the rear wheel of the vehicle is subjected to an unexpected lateral force, the rear wheel steering device of the present application can limit the rotation of the rotation output member through multiple pairs of rolling members, thereby locking the tie rod to limit the swing of the rear wheel.

[0007] During the rotation of the rotary input member, the multiple axial protrusions drive each pair of rolling members to approach each other to release the locking state of each pair of rolling members on the rotary output member, and the coupling end of the rotary input member can further drive the coupling end of the rotary output member to rotate synchronously and drive the tie rod of at least one rear wheel.

[0008] The multiple axial protrusions and multiple pairs of rolling elements of the rotary input member of the rear wheel steering device provided by the present application are arranged on the outside of the rotary output member. Under the premise of a certain volume of the rear wheel steering device, the torque output by the rotary input member in the process of driving the rotary output member to rotate synchronously is relatively large, and the torque provided by the multiple pairs of rolling elements when limiting the rotation of the rotary output member is also relatively large, thereby improving the torque carrying capacity of the rear wheel steering device. Under the premise of meeting the torque required to drive or lock the tie rod, the overall volume of the rear wheel steering device provided by the present application can be relatively reduced and reliable operation can be ensured, thereby saving the internal space of the vehicle.

[0009] In one implementation, each axial protrusion includes a radial groove, and each axial protrusion is used to accommodate the angle formed by two adjacent side surfaces through the radial groove so as to be radially embedded in a rotating output member.

[0010] In this implementation, each axial protrusion is radially nested outside the angle formed by two adjacent side surfaces through a radial groove. During the rotation of a rotary input member, each axial protrusion abuts against one of the two adjacent side surfaces through a groove wall of the radial groove to drive the rotary output member to rotate synchronously.

[0011] In one implementation, the included angle between two groove walls of the radial groove is less than or equal to the included angle formed by the two side surfaces.

[0012] In this implementation, along the circumference of a rotating output member, a gap is left between the axially protruding radial groove and the two adjacent side surfaces. The groove wall of each axially protruding radial groove needs to be rotated by a certain angle with the rotating input member before abutting against one of the two adjacent side surfaces. The angle between the two groove walls of the radial groove is set to be less than or equal to the angle formed by the two side surfaces, which can increase the fitting area between the groove wall of the radial groove and one of the two adjacent side surfaces when abutting, improve the circumferential force conditions of the rotating input member and the rotating output member, and enhance the torque bearing capacity of the rear wheel steering gear.

[0013] In one implementation, two groove walls of the radial groove in each axial protrusion are arranged symmetrically along the radial axis of the rotary output member.

[0014] In this implementation, along the circumference of the rotating output member, the inclination angle and offset distance of the two groove walls of each radial groove are equal. When each radial groove rotates clockwise or counterclockwise with the rotating input member, the contact angle and contact area when the two groove walls push the two adjacent side surfaces are equal, which is convenient for maintaining the consistency of the torque output when the steering motor rotates forward and reverse, and simplifying the control logic of the steering motor.

[0015] In one implementation, each axial protrusion includes a radial protrusion, and another radial groove is included between two adjacent side surfaces. Each axial protrusion is used to be embedded in another radial groove through the radial protrusion to radially embed in a rotating output member.

[0016] In this implementation, each axial protrusion is radially embedded in another radial groove between two adjacent side surfaces through a radial protrusion. During the rotation of a rotary input member, each axial protrusion abuts against a groove wall of another radial groove through a side wall of the radial protrusion to drive the rotary output member to rotate synchronously.

[0017] In one implementation, the included angle between two side walls of the radial protrusion is less than or equal to the included angle between two groove walls in another radial groove.

[0018] In this implementation, along the circumference of a rotating output member, a gap is left between the radial protrusion of the axial protrusion and the groove wall of another radial groove. The side walls of the radial protrusions of each axial protrusion need to be rotated by a certain angle with the rotating input member before abutting against the groove wall of another radial groove. By setting the angle between the two side walls of the radial protrusion to be less than or equal to the angle between the two groove walls in another radial groove, the fitting area between the side walls of the radial protrusion and the groove wall of another radial groove can be increased, the circumferential force conditions of the rotating input member and the rotating output member can be improved, and the torque bearing capacity of the rear wheel steering gear can be improved.

[0019] In one implementation, two side walls of the radial protrusion in each axial protrusion are arranged symmetrically along the radial axis of the rotary output member.

[0020] In this implementation, along the circumference of the rotating output member, the inclination angle and offset distance of the two side walls of each radial protrusion are respectively equal. When each radial protrusion rotates clockwise or counterclockwise with the rotating input member, the contact angle and contact area when the two side walls push the two groove walls of another radial groove are respectively equal, which is convenient for maintaining the consistency of the torque output when the steering motor rotates forward and reverse, and simplifying the control logic of the steering motor.

[0021] In one implementation, two groove walls in another radial groove are arranged symmetrically along the radial axis of the rotating output member.

[0022] In the present implementation, the inclination angle and offset distance of the two groove walls of another radial groove are respectively equal, and the contact angle and contact area of ​​the two groove walls in the other radial groove with the two side walls when receiving the drive of the radial protrusion are respectively equal, so as to facilitate maintaining the consistency of the torque received by the rotating output member as the motor rotates forward and reverse, thereby ensuring the consistency of the torque transmitted to the tie rod of the rear wheel, and facilitating the control of the rotation angle of the rear wheel.

[0023] In one implementation, along the circumference of a rotating output member, each axial protrusion includes a pair of circumferential side walls, two of the pair of circumferential side walls are used to respectively face two pairs of rolling members arranged on both sides of the axial protrusion, and each axial protrusion is used to drive a pair of rolling members to approach each other through a circumferential side wall during the rotation of a rotating input member.

[0024] In this implementation, along the circumference of a rotating output member, each axial protrusion abuts against one of the two pairs of rolling members arranged on both sides through a pair of circumferential side walls. When each axial protrusion rotates clockwise or counterclockwise with the rotating input member, one of the two circumferential side walls is used to push one of the pair of rolling members to approach the other rolling member to release the locking state of the pair of rolling members on the rotating output member.

[0025] In one implementation, the two circumferential side walls of each axial protrusion are arranged symmetrically along the radial axis of the rotary output member.

[0026] In this implementation, along the circumference of the rotating output member, the inclination angle and offset distance of a pair of circumferential side walls in each axial protrusion are respectively equal. When each circumferential side wall rotates clockwise or counterclockwise with the rotating input member, the two circumferential side walls respectively push one of the two pairs of rolling members to have equal contact angles and contact distances, which facilitates the timing of synchronously rotating the rotating output member when controlling the steering motor forward and reverse rotation, and simplifies the control logic of the steering motor.

[0027] In one implementation, along the circumference of a rotary output member, the sum of the gaps between a pair of circumferential side walls of each axial protrusion and two pairs of rolling elements arranged on both sides of the axial protrusion is smaller than the circumferential gap at the radial insertion point of the axial protrusion and a rotary output member.

[0028] In this implementation, during the rotation of the rotary input member, the timing of contact between the circumferential side wall and the pair of rolling members is earlier than the timing of the axial protrusion driving the rotary output member to rotate. That is, the axial protrusion first pushes one of the pair of rolling members to approach the other rolling member to release the locking state of the pair of rolling members on the rotary output member, and then drives the rotary output member to rotate synchronously, thereby avoiding the possible jamming phenomenon caused by the axial protrusion first contacting the rotary output member and then pushing the pair of rolling members.

[0029] In one implementation, each axial protrusion includes a radial groove, one circumferential side wall of a pair of circumferential side walls is connected to the other groove wall through one groove wall of the radial groove, and one circumferential side wall is parallel to the other groove wall.

[0030] In this implementation, when each axial protrusion rotates clockwise or counterclockwise with the rotating input member, it abuts against a pair of rolling elements and a side surface through a circumferential side wall and another groove wall. When one circumferential side wall is parallel to another groove wall, it is convenient to control the timing of each axial protrusion pushing a pair of rolling elements and abutting against a side surface, thereby avoiding a jamming phenomenon caused by another groove wall contacting a side surface before a circumferential side wall contacts a pair of rolling elements.

[0031] In one implementation, each axial protrusion includes a radial protrusion, one of a pair of circumferential side walls along the circumference of the rotary output member and one side wall of the radial protrusion are located on the same side of the axial protrusion, and the other circumferential side wall of the pair of circumferential side walls and the other side wall of the radial protrusion are located on the other side of the axial protrusion. One circumferential side wall is parallel to one side wall, and the other circumferential side wall is parallel to the other side wall.

[0032] In this implementation, when each axial protrusion rotates clockwise or counterclockwise with the rotating input member, a circumferential side wall and a side wall located on the same side respectively abut against a pair of rolling elements arranged on the same side and a groove wall in another groove facing the same side. A circumferential side wall and a side wall arranged on the same side of each axial protrusion are parallel to each other, so that the timing of each axial protrusion pushing a pair of rolling elements and abutting against a groove wall in the groove on the other side can be controlled respectively, so as to avoid a jamming phenomenon caused by the contact between a side wall and a groove wall before the contact between a circumferential side wall and a pair of rolling elements.

[0033] In one implementation, two side walls of the radial protrusion in each axial protrusion are respectively obtained by extending two circumferential side walls.

[0034] In this implementation, a pair of circumferential side walls in each axial protrusion extend radially of the rotary output member, and the two circumferential side walls are radially embedded in another groove to form two side walls of the radial protrusion. That is, the two side walls in each axial protrusion are coplanar with the two circumferential side walls. Such a structure can simplify the appearance of each axial protrusion and facilitate processing to obtain a rotary input member.

[0035] In one implementation, two adjacent axial protrusions include two opposite circumferential side walls, which are accommodated in a gap between the same side surface and the inner wall of the shell and arranged on both sides of a pair of rolling elements, and two of the two opposite circumferential side walls are respectively perpendicular to the arrangement direction of the two rolling elements in the pair of rolling elements.

[0036] In this implementation, two pairs of rolling elements are arranged on both sides of an axial protrusion along the circumference of the rotating output element, and two axial protrusions are arranged on both sides of a pair of rolling elements. That is, multiple pairs of rolling elements and multiple axial protrusions alternately surround the outer circumference of the rotating output element. The two axial protrusions each include a circumferential side wall acting on the same pair of rolling elements. Along the arrangement direction of the two rolling elements in a pair of rolling elements, the circumferential side walls respectively included in the two axial protrusions are oriented oppositely. The two opposite circumferential side walls are respectively perpendicular to the arrangement direction of the two rolling elements in a pair of rolling elements, which is convenient for controlling the spacing distance between the two circumferential side walls and the two rolling elements, thereby controlling the timing of each circumferential side wall contacting a rolling element and pushing the rolling element, which is conducive to making each axial protrusion synchronously release the locking state of multiple pairs of rolling elements on the rotating output element when the rotating input element rotates clockwise or counterclockwise.

[0037] In one implementation, along the circumference of a rotating output member, when a rotating input member stops rotating, the distance between two circumferential side walls of the two opposite circumferential side walls is greater than the width of a pair of rolling members between the two opposite circumferential side walls.

[0038] In this implementation, along the circumference of a rotating output member, the distance between two opposite circumferential side walls is greater than the sum of the distance between a pair of rolling members and the diameters of the two rolling members. That is, the two opposite circumferential side walls are arranged with a pair of rolling members at intervals, respectively. This prevents any circumferential side wall from contacting a rolling member and affecting the locking effect of the pair of rolling members on one side.

[0039] In one implementation, along a direction perpendicular to the arrangement of two rolling elements in a pair of rolling elements, the height of two circumferential side walls of two opposing circumferential side walls is greater than or equal to the radius of each rolling element in the pair of rolling elements.

[0040] In this implementation, the height dimension of each circumferential side wall exceeds the radius of the rolling element, thereby ensuring that each axial protrusion abuts against the middle of the rolling element as the rotating input element rotates, thereby facilitating pushing one rolling element toward another rolling element and controlling the timing when each circumferential side wall contacts the rolling element.

[0041] In one implementation, two opposing circumferential side walls are arranged symmetrically along the radial axis of the rotating output member.

[0042] In the present implementation, two opposite circumferential side walls of the two axial protrusions are symmetrically arranged relative to the radius of the rotating output member, and the spacing between the two circumferential side walls and the radius of the rotating output member is equal, which is convenient for controlling the spacing distance between the two circumferential side walls and the two rolling members, respectively, and is beneficial for synchronizing the timing of each axial protrusion to release the locking state of multiple pairs of rolling members on the rotating output member when the rotating input member rotates clockwise or counterclockwise, thereby simplifying the control logic of the steering motor.

[0043] In one implementation manner, each side surface is a plane.

[0044] In this implementation, each side surface of the coupling end of the rotary output member is defined as a plane, which facilitates the processing of each side surface.

[0045] In one implementation, the side surfaces are evenly distributed along the circumference of the rotating output member.

[0046] In this implementation, when the rotating input member stops rotating, the locking forces of each pair of rolling members on each side are relatively evenly distributed around the outer circumference of the rotating output member, which can improve the force condition of the coupling end of the rotating output member and avoid deformation of the coupling end of the rotating output member due to uneven force.

[0047] In one implementation, each side surface is symmetrical along a radial axis of a rotating output member.

[0048] In this implementation, each side surface is symmetrical along the radial axis of the rotating output member, so that each side surface can receive the resisting force of a pair of rolling members to limit the rotation of the rotating output member. The resisting forces of the two rolling members in the pair of rolling members acting on the side surfaces are relatively balanced, and the locking force of the rear wheel steering device provided by the application on the clockwise or counterclockwise rotation of the rear wheel tie rod tends to be consistent.

[0049] In one implementation, two adjacent side surfaces are arranged symmetrically along a radial axis of a rotating output member.

[0050] In this implementation, two adjacent side surfaces are symmetrically arranged along the radial axis of a rotating output member, so that after the two adjacent side surfaces are radially embedded with the axial protrusion, the torque received by the motor with the forward and reverse rotation is consistent, thereby ensuring the consistency of the torque transmitted to the tie rod of the rear wheel, which is convenient for controlling the rotation angle of the rear wheel.

[0051] In one implementation, the coupling end of the rotary output member is square.

[0052] In one implementation, the coupling end of the rotary output member is an equilateral triangle.

[0053] In the above two implementations, the number of side faces in the coupling end of the rotary output member is small, and the area of ​​each side face is relatively large, so it has better bearing capacity. When the rotary output member stops rotating, each side face can receive a large pressure from multiple pairs of rolling elements to limit the rotation of the rotary output member.

[0054] In one implementation, each elastic component is arranged between two rolling elements in a pair of rolling elements along the circumference of a rotation output element.

[0055] In this implementation, both ends of each elastic component can respectively abut against two rolling elements to drive the two rolling elements away from each other. The elastic component can also be accommodated in the gap between the side and the inner wall of the shell together with the pair of rolling elements, without providing a separate accommodation space for the elastic component, so as to reduce the overall volume of the rear wheel steering device provided by the present application.

[0056] In one implementation, each side surface includes a fixing groove, the notch of each fixing groove faces the inner wall of the shell along the radial direction of a rotating output member, and each fixing groove is used to fix an elastic component.

[0057] In this implementation, an elastic component is arranged between two rolling elements in the circumferential direction of the rotating output element. In the radial direction of the rotating output element, the elastic component is embedded in the fixing groove on the side to achieve positioning. The fixing groove can also be used to limit the posture of the elastic component between the two rolling elements to avoid the mutual displacement between the two rolling elements due to the deformation or displacement of the elastic component.

[0058] In one implementation, each elastic component is a U-shaped spring leaf, which includes two spring leaves and a U-shaped connecting end. The U-shaped connecting end is used to be embedded in the side and to connect the two spring leaves. The two spring leaves are used to respectively abut against two rolling elements in a pair of rolling elements.

[0059] In this implementation, the U-shaped spring has a small structure, is easy to install and fix, and is not easy to deform, and can well drive the two rolling elements to move away from each other. Each spring piece of the U-shaped spring is used to abut against a rolling element. When one spring piece is squeezed and deformed by a rolling element, the shape of the other spring piece is relatively stable. When the rotating input element rotates clockwise or counterclockwise with the steering motor, the two spring pieces are deformed alternately, which can improve the reliability of the elastic component and extend its service life.

[0060] In one implementation, a bending radius of the U-shaped connecting end of the U-shaped spring sheet is smaller than a spacing distance between the two spring sheets.

[0061] In this implementation, the U-shaped connection end is used to embed into the side, and the size of the U-shaped connection end embedded into the side is relatively large. The U-shaped spring can be better embedded in the side and prevent falling off, thereby improving the reliability of the connection between the elastic component and the side.

[0062] In one implementation, the length of each spring sheet exposed from the side is greater than the radius of the rolling element abutting against the spring sheet.

[0063] In this implementation, the length of each spring sheet exceeds the radius of the rolling element, thereby ensuring that the two spring sheets respectively abut against the middle of the two rolling elements, making it easier for the spring sheets to push the two rolling elements away from each other and reduce the overall size of the elastic component.

[0064] In one implementation, the inner wall of the shell is a circumferential surface, and when a rotating input member stops rotating, each elastic component is used to drive two rolling members in a pair of rolling members to respectively abut against the inner wall and the same side of the shell to lock the rotation of a rotating output member.

[0065] In this implementation, the gaps between the inner wall of the shell and each side surface are respectively crescent-shaped. Each gap is large in the middle along the radial dimension of the rotary output member and gradually decreases on both sides. When the two rolling members move away from each other, each rolling member abuts between the inner wall and the side surface of the shell, respectively, to limit the rotational movement of the rotary output member along one rotation direction. Two rolling members in a pair of rolling members abut against the inner wall and the same side surface of the shell, respectively, thereby limiting the rotational movement of the rotary output member in two relative rotation directions, clockwise and counterclockwise. The rear wheel steering gear of the present application thus forms the effect of two one-way clutches in series, which can reduce the overall size of the rear wheel steering gear and save the internal space of the vehicle.

[0066] In one implementation, two rolling elements in a pair of rolling elements are cylindrical, the cylindrical center axis of each rolling element is parallel to the axial direction of a rotating output element, and the cylindrical diameters of the two rolling elements are equal.

[0067] In this implementation, the cylindrical rolling element forms a larger contact surface with the side surface and the inner wall of the housing, thereby improving the load-bearing capacity of the rear wheel steering device of the present application. The diameters of the two rolling elements are equal, and the distances between the two rolling elements and the radius of the rotating output element after they are separated from each other are equal. The torques of the abutment forces formed by the two rolling elements on the side surfaces are also relatively consistent. Therefore, when the rotating input element stops rotating, the locking forces of the two rolling elements on the clockwise or counterclockwise rotation of the rotating output element are relatively consistent, which can improve the reliability of the rear wheel steering device of the present application.

[0068] In one implementation, the housing of the rear wheel steering gear includes an input side housing and an output side housing, the input side housing and the output side housing are arranged adjacent to each other along the axial direction of the rear wheel steering gear, and an output side housing is used to enclose an input side housing. One of the input side housings is used to fix the outer ring of a bearing, and the inner ring of a bearing is used to fix the transmission end of a rotating input member. One of the output side housings is used to fix the outer ring of another bearing, and the inner ring of another bearing is used to fix the transmission end of the rotating output member.

[0069] In this implementation, a housing of a rear wheel steering gear is also used to accommodate two bearings. Each bearing is used to support a rotation input member or a rotation output member to ensure that the rotation input member and the rotation output member rotate smoothly around the axis of the rear wheel steering gear.

[0070] In one implementation, the output side housing includes a mounting surface, the mounting surface includes a plurality of bolt holes, each of which is used to pass a bolt. The input side housing includes another mounting surface, the other mounting surface is used to fix the output side housing, and the other mounting surface includes a plurality of bolt slots, each of which is used to fix and accommodate a bolt passing through a bolt hole.

[0071] In one implementation, a rotating output member is connected to a tie rod through a transmission shaft. The axis of a transmission shaft is parallel to the axis of a tie rod, a transmission shaft is spaced from a tie rod along the radial direction of a rear wheel steering gear, and an end of a transmission shaft away from a steering motor along the axial direction of a rear wheel steering gear is used to connect to the middle section of a tie rod through a transmission member. During the rotation of one of the steering motors, a transmission shaft is used to drive a tie rod to move axially along a tie rod through a transmission member. During the stoppage of a steering motor, a rear wheel steering gear is used to limit the axial movement of a tie rod along a tie rod by limiting the rotation of a transmission member driven by a transmission shaft.

[0072] In this implementation, a transmission shaft is parallel to the axis of a transverse tie rod, which can reduce the radial size of the rear wheel steering gear provided by the present application and compress the volume of a transmission component, thereby facilitating the arrangement and assembly of the rear wheel steering gear.

[0073] In one implementation, a transmission member includes a transmission wheel and a screw sleeve, wherein the transmission wheel is used to be fixed to an end of a transmission shaft away from a steering motor along the axial direction of a rear wheel steering gear. The inner circumference of a screw sleeve is used to mesh with the outer circumference of a middle section of a tie rod. The transmission wheel is used to drive and connect the outer circumference of a screw sleeve along the radial direction of a rear wheel steering gear, and the diameter of the transmission wheel is smaller than the diameter of a screw sleeve.

[0074] In this implementation, the diameter of a transmission wheel is smaller than the diameter of a screw sleeve, and a transmission member forms a deceleration effect from a transmission shaft toward a screw sleeve. During the rotation of a steering motor, a transmission member is used to reduce the rotation speed of a screw sleeve and amplify the driving force output by a steering motor. When the two rear wheels make an unexpected turn, a transmission member is used to reduce the reverse driving force of a tie rod acting on a transmission shaft, so that a rear wheel steering gear can limit the rotation of a transmission shaft.

[0075] In one implementation, a tie rod includes a threaded section in the middle section along the axial direction, an inner circumferential surface of a screw sleeve is used to mesh with a threaded section, and a screw sleeve is used to rotate around the axis of a tie rod along with a transmission wheel, while driving a tie rod to move axially.

[0076] In one implementation, a plurality of balls are included between the inner circumference of a screw sleeve and a threaded section. The plurality of balls are used to reduce the friction between a screw sleeve and a tie rod, thereby improving the transmission efficiency of the rear wheel steering gear provided by the present application.

[0077] In this implementation, because the rear wheel steering gear of the present application limits the axial displacement of a tie rod through a rear wheel steering gear, a transmission member that limits the axial displacement of a tie rod through internal friction to reduce the intervention frequency of the steering motor is eliminated. Therefore, the transmission efficiency of a transmission member can be improved to reduce the power consumption of a steering motor during rotation.

[0078] In a second aspect, the present application provides a vehicle, the vehicle comprising one or more rear wheels and a rear wheel steering device provided by any of the above implementations. The rear wheel steering device is used to drive one or more rear wheels to change the direction. The vehicle of the present application has increased load-bearing capacity on the basis of having a rear wheel steering function, and has higher reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] In order to more clearly illustrate the technical solution of the present application, the drawings required for use in the implementation manner will be briefly introduced below. Obviously, the drawings described below are only some implementation manners of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0080] Figure 1 A schematic diagram of the appearance structure of a vehicle provided in one embodiment of the present application;

[0081] Figure 2 A schematic diagram of a partial structure of a vehicle provided in one embodiment of the present application;

[0082] Figure 3 A schematic diagram of the structure of a rear wheel steering device provided in one embodiment of the present application;

[0083] Figure 4 A schematic cross-sectional structure diagram of a rear wheel steering gear provided by an embodiment of the present application;

[0084] Figure 5 A schematic diagram of a partial cross-sectional structure of a rear wheel steering gear provided by an embodiment of the present application;

[0085] Figure 6 A schematic diagram of the structure of a rear wheel steering device provided in one embodiment of the present application;

[0086] Figure 7 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0087] Figure 8 A schematic diagram of a partially exploded structure of a rear wheel steering device provided in one embodiment of the present application;

[0088] Fig. 9 A schematic cross-sectional structure diagram of a rear wheel steering gear provided by an embodiment of the present application;

[0089] Fig.10 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0090] Fig.11 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0091] Fig.12 A schematic cross-sectional structure diagram of a rear wheel steering gear provided by an embodiment of the present application;

[0092] Fig.13 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0093] Fig.14 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0094] Fig.15 A schematic cross-sectional structure diagram of a rear wheel steering gear provided by an embodiment of the present application;

[0095] Fig.16 A schematic diagram of the structure of a rear wheel steering device provided in one embodiment of the present application;

[0096] Fig.17 A schematic diagram of the structure of a rear wheel steering device provided in one embodiment of the present application;

[0097] Fig.18 A schematic cross-sectional structure diagram of a rear wheel steering gear provided by an embodiment of the present application;

[0098] Fig.19 A schematic diagram of the structure of a rear wheel steering device provided in one embodiment of the present application;

[0099] Fig. 20 A schematic diagram of the structure of a rear wheel steering device provided in one embodiment of the present application;

[0100] Fig.21 A schematic cross-sectional structure diagram of a rear wheel steering gear provided by an embodiment of the present application;

[0101] Fig. 22 A partial structural schematic diagram of a rear wheel steering device provided in one embodiment of the present application;

[0102] Fig.23 A partial structural schematic diagram of a rear wheel steering device provided in one embodiment of the present application;

[0103] Fig.24 A partial structural schematic diagram of a rear wheel steering device provided in one embodiment of the present application;

[0104] Fig.25 A partial structural schematic diagram of a rear wheel steering device provided in one embodiment of the present application;

[0105] Fig.26 A partial structural schematic diagram of a rear wheel steering device provided in one embodiment of the present application;

[0106] Fig. 27 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0107] Fig.28 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0108] Fig.29A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0109] Fig.30 A partial structural schematic diagram of a rear wheel steering device provided by an embodiment of the present application;

[0110] Fig.31 A schematic diagram of the partial structure of a rear wheel steering gear provided in one embodiment of the present application.

[0111] Figure numbers: 1000-vehicle; 1001-frame; 1002-rear wheel; 1003-front wheel; 1004-steering knuckle; 200-rear wheel steering gear; 10-steering motor; 11-motor shaft; 20-transmission mechanism; 211-transmission shaft; 221-transmission member; 2211-screw sleeve; 2212-transmission wheel; 30-transverse tie rod; 31-threaded section; 32-ball; 40-housing; 41-input side housing; 411-bolt groove; 42-output side housing; 421-bolt hole; 43-bolt; 44-limiting ring; 45-circumferential surface; 50-rotating input member; 51-first transmission end; 52-first coupling end; 53-axial protrusion; 53a-first axial protrusion; 53b-second axial protrusion; 54-first radial groove; 541-first groove wall; 542-second groove wall; 55-radial Protrusion; 551-first side wall; 552-second side wall; 56-circumferential side wall; 561-first circumferential side wall; 562-second circumferential side wall; 563-third circumferential side wall; 564-fourth circumferential side wall; 60-rotational output member; 61-second transmission end; 62-second coupling end; 63-side; 631-first side; 632-second side; 64-second radial groove; 641-third groove wall; 642-fourth groove wall; 65-fixed groove; 70-rolling element; 71-first pair of rolling elements; 711-first rolling element; 712-second rolling element; 72-second pair of rolling elements; 721-third rolling element; 722-fourth rolling element; 80-elastic component; 81-spring sheet; 811-first section; 812-second section; 82-U-shaped connecting end; 90-bearing; 91-outer ring; 92-inner ring. DETAILED DESCRIPTION

[0112] The following will describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of this application.

[0113] The present application provides a rear wheel steering gear with a locking function, wherein the housing of the rear wheel steering gear is used to accommodate a rotating input member, a rotating output member, a plurality of pairs of rolling members and a plurality of elastic components, wherein the transmission end of a rotating input member is used to receive the drive of the steering motor of the vehicle, the coupling end of a rotating input member is used to drive and connect the coupling end of a rotating output member, and the transmission end of a rotating output member is used to drive and connect the tie rod of at least one rear wheel in the vehicle. The coupling end of one rotating input member includes a plurality of axial protrusions, and the plurality of axial protrusions are spaced around the coupling end of a rotating output member, and a rotating output member and each axial protrusion are embedded in the radial direction of the rotating output member. The outer peripheral surface of the coupling end of a rotating output member includes a plurality of side surfaces, and the gap between each side surface and the housing is used to accommodate a pair of rolling members, and two pairs of rolling members adjacent to each other along the circumference of a rotating output member are respectively arranged on both sides of an axial protrusion, and the two rolling members in each pair of rolling members are spaced and arranged between the two axial protrusions. Each elastic component is used to drive two rolling elements in a pair of rolling elements to move away from each other and lock the rotation of a rotating output element during the process of a rotating input element stopping rotation, and each axial protrusion is used to drive a pair of rolling elements to move toward each other and drive the rotation of a rotating output element during the process of a rotating input element rotating.

[0114] The multiple axial protrusions and multiple pairs of rolling elements of the rotary input member of the rear wheel steering device provided by the present application are arranged on the outside of the rotary output member. Under the premise of a certain volume of the rear wheel steering device, the torque output by the rotary input member in the process of driving the rotary output member to rotate synchronously is relatively large, and the torque provided by the multiple pairs of rolling elements when limiting the rotation of the rotary output member is also relatively large, thereby improving the torque carrying capacity of the rear wheel steering device. Under the premise of meeting the torque required to drive or lock the tie rod, the overall volume of the rear wheel steering device provided by the present application can be relatively reduced and reliable operation can be ensured, thereby saving the internal space of the vehicle.

[0115] The present application provides a vehicle, which includes one or more rear wheels and the rear wheel steering device provided above. The rear wheel steering device is used to drive one or more rear wheels to change the direction. The vehicle of the present application has increased load-bearing capacity on the basis of having the rear wheel steering function, and has higher reliability.

[0116] See also Figure 1 A schematic diagram of the appearance structure of a vehicle 1000 provided in one embodiment of the present application is shown.

[0117] In one embodiment, the vehicle 1000 provided by the present application includes a frame 1001, two rear wheels 1002, two front wheels 1003 and a rear wheel steering gear 200. The frame 1001 is used to rotatably connect the two rear wheels 1002 and the two front wheels 1003. The rear wheel steering gear 200 is used to be fixed to the frame 1001 and is in driving connection with the two rear wheels 1002 of the vehicle 1000. The rear wheel steering gear 200 is used to drive the two rear wheels 1002 of the vehicle 1000 to change the steering direction, thereby expanding the control range of the steering angle of the vehicle 1000 and reducing the phenomenon of understeering or oversteering of the vehicle 1000.

[0118] In some scenarios, when the vehicle 1000 needs to turn or make a U-turn with a smaller turning radius, the front wheels 1003 and the rear wheels 1002 of the vehicle 1000 can be controlled to rotate in opposite directions, thereby reducing the turning radius and improving the flexibility of the vehicle 1000. In other scenarios, when the vehicle 1000 needs to turn at a certain speed, the front wheels 1003 and the rear wheels 1002 of the vehicle 1000 can be controlled to rotate in the same direction, thereby reducing the center of mass side slip angle of the vehicle 1000, reducing the steady-state overshoot of the yaw rate of the vehicle 1000, and thus enhancing the handling stability of the vehicle 1000.

[0119] It should be noted that the number of the front wheels 1003 and rear wheels 1002 of the vehicle 1000 provided in the present application includes but is not limited to two. For example, in another embodiment, the vehicle 1000 provided in the present application may have multiple front wheels 1003 and multiple rear wheels 1002, and the rear wheel steering device 200 is drivingly connected to multiple rear wheels 1002 of the multiple rear wheels 1002 and is used to drive the multiple rear wheels 1002 to change the direction.

[0120] Please see Figure 2 and Figure 3 , Figure 2 A schematic diagram of a partial structure of a vehicle 1000 provided in one embodiment of the present application; Figure 3 A schematic structural diagram of a rear wheel steering device 200 provided in one embodiment of the present application.

[0121] like Figure 2 and Figure 3As shown, the rear wheel steering device 200 provided in the present application includes a steering motor 10, a transmission mechanism 20 and a tie rod 30, wherein the steering motor 10 is used to drive the tie rod 30 to move through the transmission mechanism 20 to drive one or two rear wheels 1002 to steer. The steering motor 10 is fixed to the frame 1001, and the motor shaft 11 of the steering motor 10 is parallel to the axial direction of the rear wheel 1002. The tie rod 30 is slidably connected to the frame 1001 along the axial direction parallel to the rear wheel 1002, and the tie rod 30 extends along the axial direction parallel to the rear wheel 1002. In one embodiment, one end of the tie rod 30 along the axial direction is connected to a rear wheel 1002 through a steering knuckle 1004. In one embodiment, the two ends of the tie rod 30 along the axial direction are connected to a rear wheel 1002 through a steering knuckle 1004. The transmission mechanism 20 is used to transmit and connect the steering motor 10 and the tie rod 30 to receive the driving force of the steering motor 10 and drive the tie rod 30 to move along its own axial direction, thereby driving the rear wheel 1002 to deflect relative to the frame 1001 to achieve steering of the rear wheel 1002.

[0122] Please see Figure 4 and Figure 5 , Figure 4 A schematic cross-sectional structure diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Figure 5 A schematic diagram of the partial cross-sectional structure of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0123] In one embodiment, the transmission mechanism 20 includes a transmission shaft 211, and the transmission mechanism 20 receives the driving force of the steering motor 10 through the transmission shaft 211. The axis of the transmission shaft 211 is parallel to the axis of the tie rod 30. Along the radial direction of the rear wheel steering gear 200, the transmission shaft 211 is spaced from the tie rod 30. Along the axial direction of the rear wheel steering gear 200, the end of the transmission shaft 211 away from the steering motor 10 is used to transmit and connect the middle section of the tie rod 30 through the transmission member 221.

[0124] During the rotation of the motor shaft 11 of the steering motor 10 , the transmission shaft 211 is used to drive the tie rod 30 to move along its own axial direction through the transmission member 221 .

[0125] When the motor shaft 11 of the steering motor 10 is not rotating, the rear wheel steering gear 200 is used to limit the axial movement of the tie rod 30 along the tie rod 30 by limiting the transmission shaft 211 to drive the transmission member 221 to rotate.

[0126] In this embodiment, the transmission shaft 211 is parallel to the axis of the transverse tie rod 30, which can reduce the radial dimension of the rear wheel steering gear 200 provided in the present application and compress the volume of the transmission member 221, thereby facilitating the arrangement and assembly of the rear wheel steering gear 200 of the present application.

[0127] In one embodiment, the transmission member 221 includes a screw sleeve 2211 and a transmission wheel 2212. The inner circumference of the screw sleeve 2211 is used to engage the outer circumference of the middle section of the tie rod 30. The transmission wheel 2212 is used to be fixed to the end of the transmission shaft 211 away from the steering motor 10 along the axial direction of the rear wheel steering gear 200. In the radial direction of the rear wheel steering gear 200, the transmission wheel 2212 is used to drive the outer circumference of the screw sleeve 2211, and the diameter of the transmission wheel 2212 is smaller than the diameter of the screw sleeve 2211.

[0128] Thus, the rotation of the steering motor 10 can drive the transmission shaft 211 to rotate, and the transmission wheel 2212 rotates with the transmission shaft 211 and drives the screw sleeve 2211 to rotate, so that the tie rod 30 can be displaced along its own axial direction. At the same time, the transmission member 221 can form a deceleration effect from the transmission shaft 211 towards the direction of the screw sleeve 2211. During the rotation of the steering motor 10, the transmission member 221 can reduce the rotating speed of the screw sleeve 2211 and amplify the driving force output by the steering motor 10, so as to effectively ensure the lateral displacement amount of the tie rod 30 generated under the drive of the screw sleeve 2211. When the two rear wheels 1002 produce unexpected steering, the transmission member 221 is used to reduce the reverse driving force of the tie rod 30 acting on the transmission shaft 211, so that the rear wheel steering device 200 provided by the application limits the rotation of the transmission shaft 211.

[0129] In one embodiment, the tie rod 30 includes a threaded section 31, and the internal thread of the inner circumferential surface of the screw sleeve 2211 is used to mesh with the threaded section 31. The screw sleeve 2211 is used to be driven by the transmission wheel 2212 and rotate relative to the tie rod 30 around the axis of the tie rod 30, while pulling the tie rod 30 to move along its own axial direction, so that the rear wheel 1002 can achieve steering. The screw sleeve 2211 is used to cooperate with the threaded section 31 of the tie rod 30 to ensure the reliability of the transmission member 221 driving the tie rod 30 to move along its own axial direction.

[0130] In one embodiment, a plurality of balls 32 are included between the inner circumference of the screw sleeve 2211 and the threaded section 31 , and the plurality of balls 32 are used to reduce the friction between the screw sleeve 2211 and the tie rod 30 , so as to improve the transmission efficiency of the rear wheel steering gear 200 of the present application.

[0131] Since the rear-wheel steering gear 200 of the present application limits the transmission shaft 211 to drive the transmission member 221 to rotate through the rear-wheel steering gear 200 to limit the axial displacement of the tie rod 30, the transmission member 221 is eliminated from limiting the axial displacement of the tie rod 30 through internal friction to reduce the intervention frequency of the steering motor 10. Therefore, the transmission efficiency of the transmission member 221 can be improved to reduce the power consumption during the rotation of the steering motor 10.

[0132] In one embodiment, the transmission method between the transmission wheel 2212 and the screw sleeve 2211 may include any one or more combinations of belt transmission, chain transmission, gear transmission, gear rack transmission, etc., to ensure that the driving force of the transmission wheel 2212 can be reliably transmitted to the screw sleeve 2211, and enable the screw sleeve 2211 to rotate around the axis of the transverse rod 30 to drive the transverse rod 30 to move along its own axial direction. The present application does not make any special limitation on this.

[0133] Please see Figures 6 to 9 , Figure 6 A schematic diagram of the structure of a rear wheel steering device 200 provided in one embodiment of the present application; Figure 7 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Figure 8 A schematic diagram of a partially exploded structure of a rear wheel steering device 200 provided in one embodiment of the present application; Fig. 9 A schematic cross-sectional structure diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0134] The rear wheel steering gear 200 provided in the present application includes a housing 40, a rotating input member 50 and a rotating output member 60. The housing 40 is used to accommodate the rotating input member 50 and the rotating output member 60. The rotating input member 50 is used to drive the motor shaft 11 of the steering motor 10 and the rotating output member 60, and the rotating output member 60 is used to drive the tie rod 30 of one or two rear wheels 1002. The rear wheel steering gear 200 provided in the present application achieves the effect of transmission connection between the motor shaft 11 of the steering motor 10 and the tie rod 30 through the rotating input member 50 and the rotating output member 60.

[0135] In one embodiment, the rotary output member 60 is connected to the tie rod 30 of one or two rear wheels 1002 via the transmission shaft 211 of the transmission mechanism 20 .

[0136] The rotating input member 50 includes a relative transmission end and a coupling end along its own axial direction. In the embodiment of the present application, the transmission end and the coupling end of the rotating input member 50 are defined as a first transmission end 51 and a first coupling end 52, respectively. Among them, the first transmission end 51 is used to receive the drive of the steering motor 10 of the vehicle 1000, and the first coupling end 52 is used for transmission connection to the rotating output member 60. Specifically, the rotating output member 60 includes a relative transmission end and a coupling end along its own axial direction. In the embodiment of the present application, the transmission end and the coupling end of the rotating output member 60 are defined as a second transmission end 61 and a second coupling end 62, respectively. The second coupling end 62 is used for transmission connection to the first coupling end 52, and the second transmission end 61 is used for transmission connection to the tie rod 30 of one or two rear wheels 1002 in the vehicle 1000. As a result, the rear wheel steering device 200 provided by the present application is able to be transmission connected to the motor shaft 11 and the tie rod 30 of the steering motor 10 through the rotating input member 50 and the rotating output member 60.

[0137] Please see Figures 10 to 12 , Fig.10 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.11 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.12 A schematic cross-sectional structure diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0138] The first coupling end 52 includes a plurality of axial protrusions 53, each of which extends in the axial direction of the rotary output member 60. A plurality of axial protrusions 53 surround the outer circumferential surface of the second coupling end 62 and are spaced apart along the circumferential direction of the rotary output member 60. Each axial protrusion 53 is used to be embedded in the outer circumferential surface of the second coupling end 62 of the rotary output member 60 along the radial direction of the rotary output member 60. Thus, the effect of transmission connection between the rotary input member 50 and the rotary output member 60 is achieved.

[0139] When the rear wheel steering device 200 provided in the present application outputs driving force through the steering motor 10, the motor shaft 11 of the steering motor 10 rotates to drive the first transmission end 51 of the rotation input member 50 to rotate around the axis of the rotation output member 60, and the first coupling end 52 of the rotation input member 50 is used to drive the plurality of axial protrusions 53 to rotate around the axis of the rotation output member 60. Because each axial protrusion 53 along the radial direction of the rotation output member 60 is used to be embedded with the outer peripheral surface of the second coupling end 62 of the rotation output shaft, the rotation of the plurality of axial protrusions 53 can drive the second coupling end 62 of the rotation output member 60 to rotate around the axis of the rotation output member 60. The second transmission end 61 of the rotation output member 60 can rotate around the axis of the rotation output member 60 along with the second coupling end 62, and drive the tie rod 30 to move along its own axial direction, thereby driving the rear wheel 1002 to deflect relative to the frame 1001 to achieve steering.

[0140] Please see Fig.13 and Fig.15 , Fig.13 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.14 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.15 A schematic cross-sectional structure diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0141] The outer circumference of the second coupling end 62 includes a plurality of side surfaces 63, or it can be understood that the plurality of side surfaces 63 surround the outer circumference of the second coupling end 62. The gap between each side surface 63 and the housing 40 is used to accommodate a pair of rolling elements 70. That is, the rear wheel steering gear 200 provided in the present application includes a plurality of pairs of rolling elements 70, and the plurality of pairs of rolling elements 70 are accommodated in the housing 40. Along the radial direction of the rotation output member 60, each pair of rolling elements 70 is located between the gap between one side surface 63 of the second coupling end 62 and the inner wall of the housing 40. Along the circumferential direction of the rotation output member 60, two adjacent pairs of rolling elements 70 are arranged on both sides of an axial protrusion 53, respectively, and the two rolling elements 70 in each pair of rolling elements 70 are arranged alternately between the two axial protrusions 53. Or it can be understood that along the circumferential direction of the rotation output member 60, a plurality of axial protrusions 53 and a plurality of pairs of rolling elements 70 alternately surround the outer circumference of the second coupling end 62.

[0142] The rear wheel steering gear 200 provided by the present application further includes a plurality of elastic components 80, which are accommodated in the housing 40. When the rotation input member 50 stops rotating, that is, when the motor shaft 11 of the steering motor 10 does not rotate, the two rolling members 70 in each pair of rolling members 70 are used to move away from each other and lock the rotation of the rotation output member 60 through the drive of an elastic component 80. When the rotation input member 50 rotates, that is, when the motor shaft 11 of the steering motor 10 rotates, the two rolling members 70 in each pair of rolling members 70 are also used to move closer to each other and drive the rotation of the rotation output member 60 through the drive of an axial protrusion 53.

[0143] When the vehicle 1000 is traveling on an uneven road surface and the two rear wheels 1002 are unexpectedly turned, the rear wheel steering device 200 provided in the present application can limit the axial displacement of the tie rod 30 to limit the angle of the unexpected turning of the two rear wheels 1002, thereby ensuring the smooth driving of the vehicle 1000. Specifically, when the rear wheel 1002 is impacted by the ground and unexpectedly turns, the rear wheel 1002 will reversely drive the tie rod 30 to move along its own axial direction, and thereby reversely drive the rotation output member 60 to rotate. When the motor shaft 11 of the steering motor 10 is not rotating, that is, when the rotation input member 50 stops rotating, the rear wheel steering device 200 drives the two rolling members 70 in each pair of rolling members 70 to move away from each other through the elastic component 80, and abuts against the same side 63 of the second coupling end 62, thereby limiting the rotation of the rotation output member 60 in the circumferential clockwise or counterclockwise direction to lock the rotation of the rotation output member 60. At the same time, the axial displacement of the tie rod 30 is limited through the rotation output member 60 , thereby limiting the steering angle of the rear wheel 1002 when it makes an unexpected turn, and limiting the swing of the rear wheel 1002 .

[0144] During this process, the motor shaft 11 of the steering motor 10 does not need to rotate. Therefore, the rear wheel steering device 200 provided by the present application can reduce the frequency of the intervention of the steering motor 10 to limit the unexpected steering of the rear wheel 1002. It avoids the phenomenon of limiting the unexpected steering of the rear wheel 1002 by driving the steering motor 10 to work in a locked state for a long time. Thereby extending the service life of the steering motor 10.

[0145] In the process of driving the rear wheel 1002 to steer by the steering motor 10 of the present application, the motor shaft 11 of the steering motor 10 rotates and drives the rotation input member 50 to rotate. The rear wheel steering device 200 provided by the present application drives the two rolling members 70 in each pair of rolling members 70 to approach each other through the axial protrusion 53. The two rolling members 70 no longer abut the same side surface 63 of the second coupling end 62 at the same time, and the locking of the rotation output member 60 by the multiple pairs of rolling members 70 is released. Since the axial protrusion 53 of the rotation input member 50 is embedded with the outer peripheral surface of the second coupling end 62 of the rotation output member 60, the rotation of the rotation input member 50 drives the rotation output member 60 to rotate synchronously, and then drives the tie rod 30 to move along its own axial direction, thereby pulling the rear wheel 1002 to deflect relative to the frame 1001 to achieve steering.

[0146] It should be noted that the two rolling elements 70 in each pair of rolling elements 70 moving away from each other can be understood as the two rolling elements 70 moving in opposite directions at the same time; it can also be understood as one of the two rolling elements 70 moving in a direction away from the other, while the other does not move. Similarly, the two rolling elements 70 in each pair of rolling elements 70 moving closer to each other can be understood as the two rolling elements 70 moving in opposite directions at the same time; it can also be understood as one of the two rolling elements 70 moving in a direction close to the other, while the other does not move.

[0147] The rear wheel steering device 200 provided in the present application achieves the effect of driving the rotary output member 60 to rotate synchronously during the rotation of the rotary input member 50 through the cooperation of the first coupling end 52 of the rotary input member 50, the second coupling end 62 of the rotary output member 60, multiple pairs of rolling members 70 and multiple elastic components 80, thereby achieving the steering of the rear wheel 1002; at the same time, it can also achieve the effect of locking the rotation of the rotary output member 60 during the process of stopping the rotation of the rotary input member 50, thereby limiting the swing of the rear wheel 1002 when the rear wheel 1002 of the vehicle 1000 is subjected to unexpected lateral force, thereby ensuring the smooth driving of the vehicle 1000.

[0148] In addition, the multiple axial protrusions 53 and multiple pairs of rolling elements 70 of the rotary input member 50 of the rear wheel steering device 200 provided by the present application are arranged outside the second coupling end 62 of the rotary output member 60, that is, the points of action of the rotary input member 50 and the rolling element 70 on the rotary output member 60 are all located on the outer peripheral surface of the second coupling end 62. As a result, the radius of the second coupling end 62 of the rotary output member 60 is increased, and during the operation of the rear wheel steering device 200 provided by the present application, the action position of the force of the transmission cooperation between the various components is relatively far away from the axis of the rotary output member 60 along the radial direction of the rotary output member 60, so that a larger transmission torque can be formed, and the load-bearing capacity of the rear wheel steering device 200 is improved.

[0149] It can be understood that, under the premise that the volume of the rear wheel steering gear 200 is certain, if the driving force output by the steering motor 10 is the same, the lever arm of the rear wheel steering gear 200 provided by the present application is larger, and the torque output by the rotating input member 50 in the process of driving the rotating output member 60 to rotate synchronously is relatively large, thereby improving the transmission efficiency. Under the condition that the locking force output by multiple pairs of rolling members 70 when locking the rotation of the rotating output member 60 is the same, the lever arm of the rear wheel steering gear 200 provided by the present application is larger, and the torque provided by multiple pairs of rolling members 70 in the process of locking the rotation of the rotating output member 60 is relatively large, thereby improving the transmission efficiency. That is, the rear wheel steering gear 200 provided by the present application improves the torque carrying capacity under the condition of a certain volume.

[0150] On the contrary, under the premise that the rear-wheel steering gear 200 meets the torque required to drive the tie rod 30 or lock the tie rod 30 along its own axial displacement, since the rear-wheel steering gear 200 provided in the present application has a larger lever arm, if the tie rod 30 is driven or locked to move the same distance along its own axial direction, the required radial dimension of the rear-wheel steering gear 200 along the rotary output member 60 is smaller. Therefore, the overall volume of the rear-wheel steering gear 200 provided in the present application is relatively reduced and reliable operation is guaranteed, thereby saving the internal space of the vehicle 1000.

[0151] Please see Figures 16 to 18 , Fig.16 A schematic diagram of the structure of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.17 A schematic diagram of the structure of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.18 A schematic cross-sectional structure diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0152] In one embodiment, each axial protrusion 53 includes a radial groove. For ease of introduction, the radial groove of each axial protrusion 53 is defined as a first radial groove 54 in the following of this application. Each first radial groove 54 is recessed from the axis of the rotary output member 60 toward the outer edge of the rotary output member 60 along the radial direction of the rotary output member 60. Each axial protrusion 53 is used to accommodate the angle formed by two adjacent side surfaces 63 through a first radial groove 54 so as to be radially embedded in a rotary output member 60. That is, each axial protrusion 53 is radially nested in the outer side of the angle formed by two adjacent side surfaces 63 through a first radial groove 54 so as to be embedded in the rotary output member 60.

[0153] Or it can be understood that two adjacent side surfaces 63 in the second coupling end 62 form an angle, and each angle is used to be embedded in a first radial groove 54 along the radial direction of the rotary output member 60. Therefore, during the rotation of the rotary input member 50, each axial protrusion 53 rotates around the axis of the rotary output member 60, and abuts against one of the two adjacent side surfaces 63 through one of the groove walls of the first radial groove 54, thereby driving the rotary output member 60 to rotate synchronously.

[0154] For ease of introduction, the present application will hereinafter define two adjacent side surfaces 63 as first side surfaces 631 and second side surfaces 632, and define two groove walls of the first radial groove 54 as first groove walls 541 and second groove walls 542. In one embodiment, the first side surface 631 and the second side surface 632 are arranged in a clockwise direction, and the first groove walls 541 and the second groove walls 542 are arranged in a clockwise direction.

[0155] When the rotary input member 50 rotates in the clockwise direction, the plurality of axial protrusions 53 rotate in the clockwise direction around the axis of the rotary output member 60, and the first groove wall 541 of each axial protrusion 53 abuts against a first side surface 631, and the first groove walls 541 of the plurality of axial protrusions 53 respectively abut against a first side surface 631, thereby the plurality of axial protrusions 53 cooperate together to drive the rotary output member 60 to rotate synchronously in the clockwise direction. When the rotary input member 50 rotates in the counterclockwise direction, the plurality of axial protrusions 53 rotate in the counterclockwise direction around the axis of the rotary output member 60, and the second groove wall 542 of each axial protrusion 53 abuts against a second side surface 632, and the second groove walls 542 of the plurality of axial protrusions 53 respectively abut against a second side surface 632, thereby the plurality of axial protrusions 53 cooperate together to drive the rotary output member 60 to rotate synchronously in the counterclockwise direction.

[0156] In one embodiment, along the circumference of the rotary output member 60, a gap is left between the angle formed by the first radial groove 54 of the axial protrusion 53 and the two adjacent side surfaces 63. That is, a gap is left between the first groove wall 541 and the first side surface 631 and / or a gap is left between the second groove wall 542 and the second side surface 632. The first coupling end 52 of the rotary input member 50 and the second coupling end 62 of the rotary output member 60 are decoupled in the initial state. This accommodates the system error of the rear wheel steering device 200 provided by the present application, avoids the rotary output member 60 from frequently contacting the rotary input member 50 when the rear wheel 1002 of the vehicle 1000 is subjected to an unexpected lateral force to reversely drive the tie rod 30 to displace and drive the rotary output member 60 to rotate in the opposite direction, and prevents the rotary input member 50 from being driven and releasing the locking state of the rotary output member 60 by the rolling member 70.

[0157] When the steering motor 10 outputs a driving force to change the steering direction of the rear wheel 1002, the motor shaft 11 of the steering motor 10 rotates to drive the rotation input member 50 to rotate, thereby driving the axial protrusion 53 to rotate. When the angle of rotation of the groove wall of the axial protrusion 53 crosses the gap between a groove wall located behind the rotation direction and an adjacent side surface 63, the groove wall abuts against the side surface 63, and the first coupling end 52 of the rotation input member 50 is coupled with the second coupling end 62 of the rotation output member 60, thereby driving the rotation output member 60 to rotate together to drive the axial displacement of the tie rod 30, and pull the rear wheel 1002 to deflect and realize steering.

[0158] In one embodiment, the included angle between the two groove walls of the first radial groove 54 is less than or equal to the included angle formed by two adjacent side surfaces 63. For ease of introduction, the included angle between the two groove walls of the first radial groove 54 is defined as α1, and the included angle formed by two adjacent side surfaces 63 is defined as β1. That is, the included angle α1 between the first groove wall 541 and the second groove wall 542 is less than or equal to the included angle β1 formed by the first side surface 631 and the second side surface 632.

[0159] Based on the axial direction of the rotary output member 60, a gap is left between the first radial groove 54 of the axial protrusion 53 and the two adjacent side surfaces 63, so that the groove wall of the first radial groove 54 of each axial protrusion 53 needs to abut against one of the two adjacent side surfaces 63 after rotating a certain angle with the rotary input member 50. In the embodiment of the present application, by setting the angle α1 between the first groove wall 541 and the second groove wall 542 to be less than or equal to the angle β1 formed by the first side surface 631 and the second side surface 632, the fitting area when the groove wall of the first radial groove 54 abuts against one of the two adjacent side surfaces 63 can be increased, the circumferential force conditions of the rotary input member 50 and the rotary output member 60 can be improved, and the torque bearing capacity of the rear wheel steering device 200 provided by the present application can be improved.

[0160] In one embodiment, the two groove walls of the first radial groove 54 in each axial protrusion 53 are arranged symmetrically along the radial axis of the rotating output member 60. That is, the first groove wall 541 and the second groove wall 542 are symmetrically arranged about a radius of the rotating output member 60. Along the circumference of the rotating output member 60, the inclination angle and offset distance of the first groove wall 541 and the second groove wall 542 of each first radial groove 54 relative to the radius of the rotating output member 60 are respectively equal. The contact angle and fitting area of ​​each first radial groove 54 when the first groove wall 541 pushes the first side surface 631 when the rotating input member 50 rotates clockwise correspond to the contact angle and fitting area of ​​each first radial groove 54 when the second groove wall 542 pushes the second side surface 632 when the rotating input member 50 rotates counterclockwise. This is conducive to maintaining the consistency of the torque output during forward and reverse rotation of the steering motor 10 and simplifying the control logic of the steering motor 10.

[0161] In one embodiment, the angle formed by two adjacent side surfaces 63 of the second coupling end 62 is arranged symmetrically along the radial axis of the rotating output member 60. That is, the first side surface 631 and the second side surface 632 are symmetrically arranged about a radius of the rotating output member 60. Along the circumference of the rotating output member 60, the inclination angle and offset distance of the first side surface 631 and the second side surface 632 relative to the radius of the rotating output member 60 are respectively equal. The contact angle and fitting area of ​​each first side surface 631 with the first groove wall 541 when receiving the push of the first radial groove 54 in the clockwise direction correspond to the contact angle and fitting area of ​​each second side surface 632 with the second groove wall 542 when receiving the push of the first radial groove 54 in the counterclockwise direction. This is conducive to maintaining the consistency of the torque received by the rotating output member 60 when the steering motor 10 rotates forward and reversely, thereby ensuring the consistency of the torque transmitted to the tie rod 30 of the rear wheel 1002, and facilitating the control of the rotation angle of the rear wheel 1002.

[0162] In one embodiment, the two groove walls of the first radial groove 54 in each axial protrusion 53 are arranged symmetrically along the radial axis of the rotating output member 60, and the angle formed by the two adjacent side surfaces 63 of the second coupling end 62 is arranged symmetrically along the radial axis of the rotating output member 60. That is, the first side surface 631 and the second side surface 632, the first groove wall 541 and the second groove wall 542 are respectively arranged symmetrically about a radius of the rotating output member 60. This is conducive to maintaining the consistency of the torque output during forward and reverse rotation of the steering motor 10, simplifying the control logic of the steering motor 10, and maintaining the consistency of the torque received by the rotating output member 60 during forward and reverse rotation of the steering motor 10, thereby ensuring the consistency of the torque transmitted to the tie rod 30 of the rear wheel 1002, and facilitating the control of the rotation angle of the rear wheel 1002.

[0163] Please see Figures 19 to 21 , Fig.19 A schematic diagram of the structure of a rear wheel steering device 200 provided in one embodiment of the present application; Fig. 20 A schematic diagram of the structure of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.21 A schematic cross-sectional structure diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0164] In one embodiment, each axial protrusion 53 includes a radial protrusion 55, and each radial protrusion 55 extends from the outer edge of the rotary output member 60 toward the axis of the rotary output member 60 along the radial direction of the rotary output member 60. Another radial groove is included between two adjacent side surfaces 63. For the sake of convenience, the radial groove between the two adjacent side surfaces 63 is defined as a second radial groove 64 in the following of this application. Each axial protrusion 53 is used to be embedded in a second radial groove 64 through a radial protrusion 55 to be radially embedded in the rotary output member 60. Or it can be understood that the rotary output member 60 is radially nested in the outer side of a radial protrusion 55 through each second radial groove 64 to be embedded with the rotary input member 50. Therefore, during the rotation of the rotary input member 50, each axial protrusion 53 abuts against a groove wall of the second radial groove 64 through a side wall of the radial protrusion 55 to drive the rotary output member 60 to rotate synchronously.

[0165] For ease of introduction, the present application will hereinafter define the two side walls of the radial protrusion 55 as the first side wall 551 and the second side wall 552, and the two groove walls of the second radial groove 64 as the third groove wall 641 and the fourth groove wall 642. In one embodiment, the first side wall 551 and the second side wall 552 are arranged in a clockwise direction, and the third groove wall 641 and the fourth groove wall 642 are arranged in a clockwise direction.

[0166] When the rotary input member 50 rotates in the clockwise direction, the plurality of axial protrusions 53 drive the radial protrusions 55 to rotate in the clockwise direction around the axis of the rotary output member 60, and the second side wall 552 of each radial protrusion 55 abuts against a fourth groove wall 642, and the second side walls 552 of the plurality of radial protrusions 55 respectively abut against a fourth groove wall 642, thereby the plurality of radial protrusions 55 cooperate together to drive the rotary output member 60 to rotate synchronously in the clockwise direction. When the rotary input member 50 rotates in the counterclockwise direction, the plurality of axial protrusions 53 drive the radial protrusions 55 to rotate in the counterclockwise direction around the axis of the rotary output member 60, and the first side wall 551 of each radial protrusion 55 abuts against a third groove wall 641, and the second side walls 552 of the plurality of radial protrusions 55 respectively abut against a third groove wall 641, thereby the plurality of radial protrusions 55 cooperate together to drive the rotary output member 60 to rotate synchronously in the counterclockwise direction.

[0167] In one embodiment, a gap is left between the radial protrusion 55 of the axial protrusion 53 and the groove wall of the second radial groove 64 along the circumference of the rotary output member 60. That is, a gap is left between the first side wall 551 and the third groove wall 641 and / or a gap is left between the second side wall 552 and the fourth groove wall 642. The first coupling end 52 of the rotary input member 50 and the second coupling end 62 of the rotary output member 60 are decoupled in the initial state. This accommodates the system error of the rear wheel steering device 200 provided by the present application, avoids the rotary output member 60 from frequently contacting the rotary input member 50 when the rear wheel 1002 of the vehicle 1000 is subjected to an unexpected lateral force to reversely drive the tie rod 30 to displace and drive the rotary output member 60 to rotate in the opposite direction, and prevents the rotary input member 50 from being driven and releasing the locking state of the rotary output member 60 by the rolling member 70.

[0168] When the steering motor 10 outputs a driving force to change the steering direction of the rear wheel 1002, the motor shaft 11 of the steering motor 10 rotates to drive the rotation input member 50 to rotate, so as to drive the radial protrusion 55 of the axial protrusion 53 to rotate. When the rotation angle of the radial protrusion 55 crosses the gap between a side wall located in front of the rotation direction and a groove wall of a second radial groove 64, the side wall abuts against the groove wall, and the first coupling end 52 of the rotation input member 50 is coupled with the second coupling end 62 of the rotation output member 60, thereby driving the rotation output member 60 to rotate together to drive the axial displacement of the tie rod 30, and pull the rear wheel 1002 to deflect and realize steering.

[0169] In one embodiment, the included angle of the two side walls of the radial protrusion 55 is less than or equal to the included angle of the two groove walls in the second radial groove 64. For ease of introduction, the included angle of the two side walls of the radial protrusion 55 is defined as α2, and the included angle of the two groove walls of the second radial groove 64 is defined as β2. That is, the included angle α2 between the first side wall 551 and the second side wall 552 is less than or equal to the included angle β2 between the third groove wall 641 and the fourth groove wall 642.

[0170] Based on the axial direction of the rotary output member 60, a gap is left between the radial protrusion 55 of the axial protrusion 53 and the two groove walls of the second radial groove 64, so that the radial protrusion 55 of each axial protrusion 53 needs to be rotated by a certain angle with the rotary input member 50 before abutting against one of the groove walls of the second radial groove 64. In the embodiment of the present application, by setting the angle between the first side wall 551 and the second side wall 552 to be less than or equal to the angle between the third groove wall 641 and the fourth groove wall 642, the contact area between the side wall of the radial protrusion 55 and the groove wall of the second radial groove 64 can be increased, the circumferential force conditions of the rotary input member 50 and the rotary output member 60 can be improved, and the torque bearing capacity of the rear wheel steering device 200 provided by the present application can be improved.

[0171] In one embodiment, the two side walls of the radial protrusion 55 in each axial protrusion 53 are arranged symmetrically along the radial axis of the rotating output member 60. That is, the first side wall 551 and the second side wall 552 are symmetrically arranged about a radius of the rotating output member 60. Along the circumference of the rotating output member 60, the inclination angle and offset distance of the first side wall 551 and the second side wall 552 of each first radial protrusion 55 relative to the radius of the rotating output member 60 are respectively equal. The contact angle and fitting area of ​​each first radial protrusion 55 when the second side wall 552 pushes the fourth groove wall 642 when the rotating input member 50 rotates clockwise correspond to the contact angle and fitting area of ​​each first radial protrusion 55 when the first side wall 551 pushes the third groove wall 641 when the rotating input member 50 rotates counterclockwise. This is conducive to maintaining the consistency of the torque output during forward and reverse rotation of the steering motor 10 and simplifying the control logic of the steering motor 10.

[0172] In one embodiment, the two groove walls in the second radial groove 64 are arranged symmetrically along the radial axis of the rotary output member 60. That is, the third groove wall 641 and the fourth groove wall 642 are symmetrically arranged about a radius of the rotary output member 60. Along the circumference of the rotary output member 60, the inclination angles and offset distances of the third groove wall 641 and the fourth groove wall 642 of each second radial groove 64 relative to the radius of the rotary output member 60 are respectively equal. The contact angle and fitting area of ​​the fourth groove wall 642 of each second radial groove 64 with the second side wall 552 when receiving the clockwise push of the radial protrusion 55 are respectively the same as the contact angle and fitting area of ​​the third groove wall 641 of each second radial groove 64 with the first side wall 551 when receiving the counterclockwise push of the radial protrusion 55. This helps to maintain the consistency of the torque received by the rotating output member 60 when the steering motor 10 rotates forward and reverse, thereby ensuring the consistency of the torque transmitted to the tie rod 30 of the rear wheel 1002, making it easier to control the rotation angle of the rear wheel 1002.

[0173] In one embodiment, the two side walls of the radial protrusion 55 in each axial protrusion 53 are arranged symmetrically along the radial axis of the rotation output member 60, and the two groove walls in the second radial groove 64 are arranged symmetrically along the radial axis of the rotation output member 60. That is, the first side wall 551 and the second side wall 552, the third groove wall 641 and the fourth groove wall 642 are respectively arranged symmetrically about the radius of the rotation output member 60. This is conducive to maintaining the consistency of the torque output when the steering motor 10 rotates forward and reverse, simplifying the control logic of the steering motor 10, and maintaining the consistency of the torque received by the rotation output member 60 when the steering motor 10 rotates forward and reverse, thereby ensuring the consistency of the torque transmitted to the tie rod 30 of the rear wheel 1002, and facilitating the control of the rotation angle of the rear wheel 1002.

[0174] Please see Fig. 22 and Fig.23,in Fig. 22 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.23 A partial structural schematic diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0175] In one embodiment, along the circumference of the rotary output member 60, each axial protrusion 53 includes a pair of circumferential side walls 56. Two circumferential side walls 56 in the pair of circumferential side walls 56 are used to face two pairs of rolling members 70 arranged on the axial protrusion 53 respectively, and each axial protrusion 53 is used to drive two rolling members 70 in a pair of rolling members 70 to approach each other through one circumferential side wall 56 during the rotation of one rotary input member 50.

[0176] For the convenience of introduction, the two pairs of rolling elements 70 located on both sides of an axial protrusion 53 along the circumference of the rotary output element 60 are respectively defined as the first pair of rolling elements 71 and the second pair of rolling elements 72, and the two circumferential side walls 56 of a pair of circumferential side walls 56 of each axial protrusion 53 are respectively defined as the first circumferential side wall 561 and the second circumferential side wall 562. In one embodiment, the first pair of rolling elements 71, the first circumferential side wall 561 of the axial protrusion 53, the second circumferential side wall 562 of the axial protrusion 53, and the second pair of rolling elements 72 are arranged in sequence along the clockwise direction. For the convenience of introduction, the two rolling elements 70 in the first pair of rolling elements 71 are respectively defined as the first rolling element 711 and the second rolling element 712, and the two rolling elements 70 in the second pair of rolling elements 72 are respectively defined as the third rolling element 721 and the fourth rolling element 722. In one embodiment, the first rolling element 711 , the second rolling element 712 , the first circumferential side wall 561 , the second circumferential side wall 562 , the third rolling element 721 , and the fourth rolling element 722 are sequentially arranged in a clockwise direction.

[0177] When the rotation input member 50 drives the axial protrusions 53 to rotate together in the clockwise direction, each axial protrusion 53 abuts against the third rolling member 721 through the second circumferential side wall 562, and pushes the third rolling member 721 to approach the fourth rolling member 722, so as to release the locking state of the second pair of rolling members 72 on the rotation output member 60. When the rotation input member 50 drives the axial protrusions 53 to rotate together in the counterclockwise direction, each axial protrusion 53 abuts against the second rolling member 712 through the first circumferential side wall 561, and pushes the second rolling member 712 to approach the first rolling member 711, so as to release the locking state of the first pair of rolling members 71 on the rotation output member 60.

[0178] In one embodiment, along the circumference of the rotary output member 60 , the sum of the gaps between a pair of circumferential side walls 56 of each axial protrusion 53 and two pairs of rolling elements 70 arranged on both sides of the axial protrusion 53 is smaller than the circumferential gap at the radial insertion point between the axial protrusion 53 and the rotary output member 60 .

[0179] Corresponding to the embodiment in which the axial protrusion 53 includes the first radial groove 54, along the circumference of the rotary output member 60, the sum of the gap between the first circumferential side wall 561 and the second rolling member 712 and the gap between the second circumferential side wall 562 and the third rolling member 721 is smaller than the circumferential gap between the first groove wall 541 and the second groove wall 542. Alternatively, it can be understood that the difference between the arc length between the second rolling member 712 and the third rolling member 721 and the arc length between the first circumferential side wall 561 and the second circumferential side wall 562 is smaller than the difference between the arc length between the first groove wall 541 and the second groove wall 542 and the arc length between the first side surface 631 and the second side surface 632.

[0180] Corresponding to the embodiment in which the axial protrusion 53 includes the radial protrusion 55, along the circumference of the rotary output member 60, the sum of the gap between the first circumferential side wall 561 and the second rolling member 712 and the gap between the second circumferential side wall 562 and the third rolling member 721 is smaller than the circumferential gap between the third groove wall 641 and the fourth groove wall 642. Or it can be understood that the difference between the arc length between the second rolling member 712 and the third rolling member 721 and the arc length between the first circumferential side wall 561 and the second circumferential side wall 562 is smaller than the difference between the arc length between the third groove wall 641 and the fourth groove wall 642 and the arc length between the first side wall 551 and the second side wall 552.

[0181] Thus, it can be ensured that during the rotation of the rotation input member 50, the contact timing between the circumferential side wall 56 and the rolling member 70 is earlier than the timing when the axial protrusion 53 drives the rotation output member 60 to rotate. That is, the axial protrusion 53 first pushes one of the pair of rolling members 70 to approach the other rolling member 70 to release the locking state of the pair of rolling members 70 on the rotation output member 60, and then drives the rotation output member 60 to rotate synchronously, thereby avoiding the possible jamming phenomenon caused by the axial protrusion 53 first contacting the rotation output member 60 and then pushing the pair of rolling members 70.

[0182] In one embodiment, the two circumferential side walls 56 in each axial protrusion 53 are arranged symmetrically along the radial axis of the rotating output member 60. That is, the first circumferential side wall 561 and the second circumferential side wall 562 are symmetrically arranged about a radius of the rotating output member 60. Along the circumference of the rotating output member 60, the inclination angle and offset distance of a pair of circumferential side walls 56 in each axial protrusion 53 relative to the radius of the rotating output member 60 are respectively equal. When each circumferential side wall 56 rotates clockwise with the rotating input member 50, the contact angle and contact distance when the second circumferential side wall 562 pushes the third rolling member 721 correspond to the contact angle and contact distance when each circumferential side wall 56 rotates counterclockwise with the rotating input member 50, respectively. This facilitates the control of the timing of driving the rotating output member 60 to rotate synchronously when the steering motor 10 rotates forward and reverse, and simplifies the control logic of the steering motor 10.

[0183] In one embodiment, each axial protrusion 53 includes a first radial groove 54, one of the pair of circumferential side walls 56 is connected to the other groove wall through one groove wall of the first radial groove 54, and one circumferential side wall 56 is parallel to the other groove wall. That is, the first circumferential side wall 561 is connected to the second groove wall 542 through the first groove wall 541, and the second circumferential side wall 562 is connected to the first groove wall 541 through the second groove wall 542. Moreover, the first circumferential side wall 561 is parallel to the second groove wall 542, and the second circumferential side wall 562 is parallel to the first groove wall 541.

[0184] When each axial protrusion 53 rotates clockwise with the rotary input member 50, it abuts against the third rolling member 721 and the first side surface 631 through the second circumferential side wall 562 and the first groove wall 541. Because the second circumferential side wall 562 is parallel to the first groove wall 541, it is convenient to control the timing of each axial protrusion 53 pushing the third rolling member 721 and the first side surface 631, thereby avoiding the stuck phenomenon caused by the contact between the first groove wall 541 and the first side surface 631 before the contact between the second circumferential side wall 562 and the third rolling member 721.

[0185] When each axial protrusion 53 rotates counterclockwise with the rotation input member 50, it abuts against the second rolling member 712 and the second side surface 632 through the first circumferential side wall 561 and the second groove wall 542. Since the first circumferential side wall 561 and the second groove wall 542 are parallel, it is convenient to control the timing of each axial protrusion 53 pushing the second rolling member 712 and the second side surface 632, thereby avoiding the stuck phenomenon caused by the contact between the second groove wall 542 and the second side surface 632 before the contact between the first circumferential side wall 561 and the second rolling member 712.

[0186] Please see Fig.24 and Fig.25 ,in Fig.24 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.25 A partial structural schematic diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0187] In one embodiment, each axial protrusion 53 includes a radial protrusion 55. Along the circumference of the rotary output member 60, one of the pair of circumferential side walls 56 and one side wall of the radial protrusion 55 are located on the same side of the axial protrusion 53, and the other circumferential side wall 56 of the pair of circumferential side walls 56 and the other side wall of the radial protrusion 55 are located on the other side of the axial protrusion 53. One circumferential side wall 56 is parallel to one side wall, and the other circumferential side wall 56 is parallel to the other side wall. That is, along the circumference of the rotary output member 60, the first circumferential side wall 561 and the first side wall 551 are located on the same side of the axial protrusion 53, and the second circumferential side wall 562 and the second side wall 552 are located on the other side of the axial protrusion 53. Moreover, the first circumferential side wall 561 is parallel to the first side wall 551, and the second circumferential side wall 562 is parallel to the second side wall 552.

[0188] When each axial protrusion 53 rotates clockwise with the rotary input member 50, it abuts against the third rolling member 721 and the fourth groove wall 642 respectively through the second circumferential side wall 562 and the second side wall 552. Because the second circumferential side wall 562 is parallel to the second side wall 552, it is convenient to control the time when each axial protrusion 53 pushes the third rolling member 721 and the fourth groove wall 642 respectively, thereby avoiding the jamming phenomenon caused by the contact between the second side wall 552 and the fourth groove wall 642 before the contact between the second circumferential side wall 562 and the third rolling member 721.

[0189] When each axial protrusion 53 rotates counterclockwise with the rotation input member 50, it abuts against the second rolling member 712 and the third groove wall 641 through the first circumferential side wall 561 and the first side wall 551. Because the first circumferential side wall 561 is parallel to the first side wall 551, it is convenient to control the time when each axial protrusion 53 pushes the second rolling member 712 and the third groove wall 641, thereby avoiding the jamming phenomenon caused by the contact between the first side wall 551 and the third groove wall 641 before the contact between the first circumferential side wall 561 and the second rolling member 712.

[0190] In one embodiment, the two side walls of the radial protrusion 55 in each axial protrusion 53 are respectively extended by two circumferential side walls 56. That is, the first circumferential side wall 561 and the second circumferential side wall 562 extend respectively along the radial direction of the rotary output member 60 toward the axis of the rotary output member 60. Among them, the part of the first circumferential side wall 561 embedded in the second radial groove 64 along the radial direction of the rotary output member 60 is used to constitute the first side wall 551 of the radial protrusion 55, and the part of the second circumferential side wall 562 embedded in the second radial groove 64 along the radial direction of the rotary output member 60 is used to constitute the second side wall 552 of the radial protrusion 55. That is, the first side wall 551 in each axial protrusion 53 is coplanar with the first circumferential side wall 561, and the second side wall 552 is coplanar with the second circumferential side wall 562. Such a structural design can simplify the appearance of each axial protrusion 53, and facilitate the processing to obtain the rotary input member 50.

[0191] Please see Fig.26 , Fig.26 A partial structural schematic diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0192] In one embodiment, two adjacent axial protrusions 53 include two opposite circumferential side walls 56, which are accommodated in the gap between the same side surface 63 and the inner wall of the shell 40 and are arranged on both sides of a pair of rolling elements 70. Two of the two opposite circumferential side walls 56 are respectively perpendicular to the arrangement direction of two rolling elements 70 in the pair of rolling elements 70.

[0193] Along the circumference of the rotary output member 60, two pairs of rolling members 70 are arranged on both sides of the same axial protrusion 53, and the two axial protrusions 53 are arranged on both sides of the same pair of rolling members 70. That is, multiple pairs of rolling members 70 and multiple axial protrusions 53 alternately surround the outer circumference of the rotary output member 60. Two adjacent axial protrusions 53 each include a circumferential side wall 56 acting on the same pair of rolling members 70. Along the arrangement direction of the two rolling members 70 in the pair of rolling members 70, the circumferential side walls 56 respectively included in the two axial protrusions 53 are opposite to each other. The two opposite circumferential side walls 56 are respectively perpendicular to the arrangement direction of the two rolling members 70 in the pair of rolling members 70.

[0194] For ease of introduction, two adjacent axial protrusions 53 are defined as a first axial protrusion 53a and a second axial protrusion 53b, respectively. In one embodiment, the first axial protrusion 53a and the second axial protrusion 53b are arranged in a clockwise direction. The second circumferential side wall 562 of the first axial protrusion 53a is arranged opposite to the first circumferential side wall 561 of the second axial protrusion 53b. For ease of introduction, the circumferential side walls 56 that are arranged opposite to each other in the first axial protrusion 53a and the second axial protrusion 53b are defined as a third circumferential side wall 563 and a fourth circumferential side wall 564, respectively. The third circumferential side wall 563 is the second circumferential side wall 562 of the first axial protrusion 53a, and the fourth circumferential side wall 564 is the first circumferential side wall 561 of the second axial protrusion 53b. The third circumferential side wall 563 and the fourth circumferential side wall 564 are accommodated in the gap between the second side surface 632 and the inner wall of the housing 40. The third circumferential side wall 563 and the fourth circumferential side wall 564 are respectively located on both sides of the second pair of rolling elements 72. Further, the third circumferential side wall 563 and the fourth circumferential side wall 564 are respectively perpendicular to the arrangement direction of the two rolling elements 70 in the second pair of rolling elements 72. That is, the third circumferential side wall 563 and the fourth circumferential side wall 564 both extend in a direction perpendicular to the arrangement direction of the two rolling elements 70 in the second pair of rolling elements 72.

[0195] In the embodiment of the present application, the extending direction of the two circumferential side walls 56 acting on the same pair of rolling elements 70 is restricted to be perpendicular to the arrangement direction of the two rolling elements 70 in the pair of rolling elements 70, so as to control the spacing distance between the two circumferential side walls 56 and the two rolling elements 70 in the pair of rolling elements 70, thereby controlling the timing of each circumferential side wall 56 contacting a rolling element 70 and pushing the rolling element 70. This is conducive to the synchronous release of the locking state of the multiple pairs of rolling elements 70 on the rotating output element 60 by each axial protrusion 53 when rotating with the rotating input element 50.

[0196] In one embodiment, along the circumference of the rotary output member 60, the distance between two circumferential side walls 56 of the two opposite circumferential side walls 56 when the rotary input member 50 stops rotating is greater than the width of a pair of rolling members 70 between the two opposite circumferential side walls 56. That is, the distance between the third circumferential side wall 563 and the fourth circumferential side wall 564 is greater than the sum of the diameter of the third rolling member 721 of the second pair of rolling members 72, the diameter of the fourth rolling member 722, and the distance between the third rolling member 721 and the fourth rolling member 722.

[0197] In the embodiment of the present application, along the circumference of the rotary output member 60, the distance between the two opposite circumferential side walls 56 is greater than the sum of the distance between the pair of rolling members 70 and the diameters of the two rolling members 70, that is, the two opposite circumferential side walls 56 are arranged with a pair of rolling members 70 at intervals. This can prevent any one of the two opposite circumferential side walls 56 from contacting any one of the rolling members 70 and affecting the locking effect of the pair of rolling members 70 on one of the side surfaces 63.

[0198] In one embodiment, along the direction perpendicular to the arrangement of the two rolling elements 70 in the pair of rolling elements 70, the height of the two circumferential side walls 56 in the two opposite circumferential side walls 56 is greater than or equal to the radius of each rolling element 70 in the pair of rolling elements 70. That is, along the direction perpendicular to the arrangement of the two rolling elements 70 in the pair of rolling elements 70, the height of the third circumferential side wall 563 and the fourth circumferential side wall 564 is greater than or equal to the radius of each rolling element 70 in the pair of rolling elements 70.

[0199] In this embodiment, the height dimension of each circumferential side wall 56 is set to be at least greater than the radius of the rolling element 70, thereby ensuring that each axial protrusion 53 abuts against the middle of the rolling element 70 during the rotation of the rotating input member 50, thereby facilitating the pushing of one of the pair of rolling elements 70 toward the other rolling element 70, and facilitating the control of the timing of the contact between each circumferential side wall 56 and the rolling element 70.

[0200] In one embodiment, the two opposite circumferential side walls 56 are arranged symmetrically along the radial axis of the rotary output member 60. That is, the third circumferential side wall 563 and the fourth circumferential side wall 564 are symmetrically arranged about a radius of the rotary output member 60. The distances between the third circumferential side wall 563 and the fourth circumferential side wall 564 and the radius of the rotary output member 60 are respectively equal. In the embodiment of the present application, the distances between the two opposite circumferential side walls 56 and the radius of the rotary output member 60 are respectively equal, which is convenient for controlling the spacing distance between the two opposite circumferential side walls 56 and the two rolling elements 70 of the pair of rolling elements 70, and is conducive to making the angles of rotation required for each axial protrusion 53 to release the locking state of the multiple pairs of rolling elements 70 on the rotary output member 60 when the rotary input member 50 rotates clockwise and counterclockwise. That is, it is beneficial to make the timing when each axial protrusion 53 contacts multiple pairs of rolling elements 70 to release the locking state of the rotary output element 60 when the circumferential side wall 56 rotates clockwise with the rotary input element 50 to be the same as the timing when each axial protrusion 53 contacts multiple pairs of rolling elements 70 to release the locking state of the rotary output element 60 when the circumferential side wall 56 rotates counterclockwise with the rotary input element 50, thereby simplifying the control logic of the steering motor 10.

[0201] In one embodiment, each side surface 63 is a plane. Setting each side surface 63 of the second coupling end 62 of the rotary output member 60 as a plane simplifies the structure of the rotary output member 60 and facilitates the processing of each side surface 63 .

[0202] In one embodiment, the side surfaces 63 are evenly distributed along the circumference of the rotary output member 60. Therefore, when the rotary input member 50 is not rotating and the pairs of rolling members 70 are locking the rotary output member 60, the side surfaces 63 are relatively evenly surrounded by the outer circumference of the rotary output member 60 by the locking force of the pairs of rolling members 70, thereby improving the force condition of the second coupling end 62 of the rotary output member 60 and preventing the second coupling end 62 of the rotary output member 60 from being deformed due to uneven force.

[0203] In one embodiment, each side surface 63 is symmetrical along the radial axis of the rotating output member 60. That is, each side surface 63 is symmetrically arranged about a radius of the rotating output member 60. This arrangement is conducive to each side surface 63 receiving the resisting force of a pair of rolling members 70 to limit the rotation of the rotating output member 60. At the same time, since each side surface 63 is symmetrical along the radial axis of the rotating output member 60, the resisting force of the two rolling members 70 in each pair of rolling members 70 acting on one side surface 63 is relatively balanced, so the rear wheel steering device 200 provided in the present application tends to have the same locking force on the tie rod 30 of the rear wheel 1002 in the clockwise and counterclockwise directions.

[0204] In one embodiment, two adjacent side surfaces 63 are arranged symmetrically along the radial axis of the rotation output member 60. That is, the first side surface 631 and the second side surface 632 are symmetrically arranged about a radius of the rotation output member 60. As a result, after the first side surface 631 and the second side surface 632 are radially embedded with the axial protrusion 53, the torque received during the forward and reverse rotation of the motor can be consistent, thereby ensuring that the torque transmitted to the tie rod 30 of the rear wheel 1002 is consistent, which facilitates the control of the rotation angle of the rear wheel 1002.

[0205] In one embodiment, the second coupling end 62 of the rotation output member 60 is a square, that is, the orthographic projection of the second coupling end 62 in the radial plane of the rotation output member 60 is a square.

[0206] In one embodiment, the second coupling end 62 of the rotation output member 60 is an equilateral triangle, that is, the orthographic projection of the second coupling end 62 in the radial plane of the rotation output member 60 is an equilateral triangle.

[0207] In the above two embodiments, the number of side faces 63 in the second coupling end 62 of the rotation output member 60 is small, and the area of ​​each side face 63 is relatively large, so as to have better bearing capacity. When the rotation output member 60 is not rotating, each side face 63 can receive a large pressure from multiple pairs of rolling elements 70 to limit the rotation of the rotation output member 60.

[0208] In one embodiment, each elastic component 80 is arranged between two rolling elements 70 in a pair of rolling elements 70 along the circumference of the rotating output member 60. That is, along the circumference of the rotating output member 60, one rolling element 70, the elastic component 80, and the other rolling element 70 are arranged in sequence. Along the arrangement direction of the two rolling elements 70 in the pair of rolling elements 70, the two ends of the elastic component 80 can respectively abut against the two rolling elements 70 to drive the two rolling elements 70 away from each other. Along the arrangement direction perpendicular to the two rolling elements 70 in the pair of rolling elements 70, the elastic component 80 is accommodated in the gap between one side surface 63 and the inner wall of the housing 40. By accommodating the elastic component 80 together with the pair of rolling elements 70 in the gap between the side surface 63 and the inner wall of the housing 40, it is not necessary to set a separate accommodation space for the elastic component 80, so as to reduce the overall volume of the rear wheel steering device 200 provided by the present application.

[0209] Please see Figure 27 to Figure 29 ,in Fig. 27 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.28 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.29 A partial structural schematic diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0210] In one embodiment, each side surface 63 includes a fixing groove 65, and the notch of each fixing groove 65 faces the inner wall of the housing 40 along the radial direction of the rotating output member 60, and each fixing groove 65 is used to fix an elastic component 80. The elastic component 80 is arranged between two rolling members 70 in a pair of rolling members 70 along the circumferential direction of the rotating output member 60. Along the radial direction of the rotating output member 60, the elastic component 80 is embedded in the fixing groove 65 of the side surface 63 to achieve positioning. The fixing groove 65 can also be used to limit the posture of the elastic component 80 between the two rolling members 70 to avoid the mutual displacement between the two rolling members 70 affected by the deformation or displacement of the elastic component 80.

[0211] In one embodiment, each elastic component 80 is a U-shaped spring leaf, and the U-shaped spring leaf includes two spring leaves 81 and a U-shaped connecting end 82. In one embodiment, along the radial direction of the rotating output member 60, the inner wall of the housing 40, the two spring leaves 81, and the U-shaped connecting end 82 are arranged in sequence. The U-shaped connecting end 82 is used to be embedded in the fixing groove 65 of the side 63, and the U-shaped connecting end 82 is used to connect the two spring leaves 81. The two spring leaves 81 extend from the U-shaped connecting end 82 toward the inner wall of the housing 40 along a direction perpendicular to the arrangement of the two rolling elements 70 in the pair of rolling elements 70. Along the circumferential direction of the rotating output member 60, the two spring leaves 81 are located between the two rolling elements 70 of the pair of rolling elements 70, and the two spring leaves 81 are arranged at intervals along the arrangement direction of the two rolling elements 70 in the pair of rolling elements 70. The two spring leaves 81 are used to abut the two rolling elements 70 in the pair of rolling elements 70, respectively.

[0212] Based on the fact that the U-shaped spring piece has a small structure, is easy to install and fix, and is not easy to deform, the present application sets the elastic component 80 as a U-shaped spring piece, which can better drive the two rolling elements 70 to move away from each other. Each spring piece 81 of the U-shaped spring piece is used to abut against a rolling element 70, and when one spring piece 81 is squeezed and deformed by a rolling element 70, the shape of the other spring piece 81 is relatively stable. When the rotating input member 50 rotates clockwise or counterclockwise with the steering motor 10, the two spring pieces 81 are deformed alternately, which can improve the reliability of the elastic component 80 and extend its service life.

[0213] In one embodiment, the bending radius of the U-shaped connection end 82 of the U-shaped spring piece is smaller than the spacing distance between the two spring pieces 81. The U-shaped connection end 82 is used to be embedded in the fixing groove 65 of the side 63. By setting the bending radius of the U-shaped connection end 82 smaller than the spacing distance between the two spring pieces 81, the size of the U-shaped connection end 82 embedded in the side 63 is relatively large, and the U-shaped spring piece can be better embedded in the fixing groove 65 of the side 63 and prevented from falling off, thereby improving the reliability of the connection between the elastic component 80 and the side 63.

[0214] In one embodiment, the length of each spring piece 81 exposed from the side 63 is greater than the radius of the rolling element 70 abutting against the spring piece 81. In one embodiment, each spring piece 81 includes a first section 811 and a second section 812 along its length direction. The first section 811 is used to extend into the fixing groove 65 of the side 63 and connect with the U-shaped connecting end 82, and is used to abut against the groove wall of the fixing groove 65 to limit the displacement of the U-shaped spring piece. The second section 812 is used to expose the side 63 and extend between two rolling elements 70 in a pair of rolling elements 70, and the second section 812 is used to abut against the rolling element 70, and the length of the second section 812 is greater than the radius of the rolling element 70.

[0215] In the embodiment of the present application, by setting the length of each second section 812 to exceed the radius of the rolling element 70, it can be ensured that each spring piece 81 can abut the middle of the rolling element 70 respectively, so that the spring piece 81 can push the two rolling elements 70 away from each other.

[0216] In one embodiment, the housing 40 of the rear wheel steering device 200 provided in the present application includes an input side housing 41 and an output side housing 42 (eg Fig. 9 As shown in FIG. 1 , the input side housing 41 and the output side housing 42 are arranged adjacent to each other along the axial direction of the motor shaft 11 of the steering motor 10, and the output side housing 42 is used to enclose the input side housing 41. The input side housing 41 is used to fix the outer ring 91 of the bearing 90, and the inner ring 92 of the bearing 90 is used to fix the first transmission end 51 of the rotating input member 50. The output side housing 42 is used to fix the outer ring 91 of another bearing 90, and the inner ring 92 of another bearing 90 is used to fix the second transmission end 61 of the rotating output member 60.

[0217] That is, the present application forms the housing 40 of the rear wheel steering gear 200 by enclosing the input side housing 41 by the output side housing 42. At the same time, the rear wheel steering gear 200 provided by the present application also includes two bearings 90, and the two bearings 90 are both accommodated and fixed in the housing 40. One of the bearings 90 is used to support the rotating input member 50, and the other bearing 90 is used to support the rotating output member 60. The present application supports the rotating input member 50 and the rotating output member 60 respectively by two bearings 90 to ensure that the rotating input member 50 and the rotating output member 60 rotate smoothly around the axis of the rear wheel steering gear 200.

[0218] In one embodiment, the output side housing 42 includes a mounting surface, the mounting surface includes a plurality of bolt holes 421, and each bolt hole 421 is used to pass a bolt. The input side housing 41 includes another mounting surface, the other mounting surface is used to fix the output side housing 42, and the other mounting surface includes a plurality of bolt grooves 411, and each bolt groove 411 is used to fix and accommodate a bolt 43 passing through a bolt hole 421.

[0219] Please see Fig.30 and Fig.31, Fig.30 A partial structural schematic diagram of a rear wheel steering device 200 provided in one embodiment of the present application; Fig.31 A partial structural schematic diagram of a rear wheel steering gear 200 provided in one embodiment of the present application.

[0220] In one embodiment, the inner wall of the housing 40 further includes a limiting ring 44. The axis of the limiting ring 44 coincides with the axis of the rotating output member 60. Along the radial direction of the rotating output member 60, the limiting ring 44 is used to surround the axial protrusion 53 and the periphery of the rolling member 70. The limiting ring 44 is used to cooperate with the side surface 63 of the second coupling end 62 to limit the displacement of the rolling member 70 along the radial direction of the rotating output member 60.

[0221] In one embodiment, the inner wall of the housing 40 includes a circumferential surface 45. When a rotating input member 50 stops rotating, each elastic component 80 is used to drive two rolling members 70 in a pair of rolling members 70 to respectively abut the circumferential surface 45 of the inner wall of the housing 40 and the same side surface 63 to lock the rotation of a rotating output member 60.

[0222] In the embodiment of the present application, the gaps between the circumferential surface 45 of the inner wall of the housing 40 and each side surface 63 are respectively crescent-shaped. Each gap is large in the middle along the radial dimension of the rotation output member 60 and gradually decreases on both sides. When the two rolling members 70 are away from each other, each rolling member 70 abuts between the circumferential surface 45 of the inner wall of the housing 40 and the side surface 63, respectively, to limit the rotational movement of the rotation output member 60 along one rotation direction. Two rolling members 70 in a pair of rolling members 70 abut against the circumferential surface 45 of the inner wall of the housing 40 and the same side surface 63, respectively, thereby limiting the rotational movement of the rotation output member 60 along two rotation directions relative to clockwise and counterclockwise. The rear wheel steering gear 200 of the present application thus forms the effect of two one-way clutches in series, which can reduce the overall size of the rear wheel steering gear 200 and save the internal space of the vehicle 1000.

[0223] In one embodiment, two rolling elements 70 in a pair of rolling elements 70 are cylindrical, the cylindrical center axis of each rolling element 70 is parallel to the axial direction of a rotating output element 60, and the cylindrical diameters of the two rolling elements 70 are equal.

[0224] The cylindrical rolling element 70 forms a larger contact surface with the side surface 63 and the inner wall of the housing 40, thereby improving the load-bearing capacity of the rear wheel steering device 200 of the present application. The diameters of the two rolling elements 70 are equal, and the distances between the two rolling elements 70 and the radius of the rotating output element 60 after the two rolling elements 70 are separated from each other are equal. The torques of the abutment forces formed by the two rolling elements 70 on the side surface 63 are also relatively consistent. Therefore, when the rotating input element 50 stops rotating, the locking forces of the two rolling elements 70 on the rotating output element 60 in the clockwise direction and the counterclockwise direction are relatively consistent, which can improve the reliability of the rear wheel steering device 200 of the present application.

[0225] In one embodiment, the inner wall of the housing 40 includes a circumferential surface 45, and the two rolling elements 70 in each pair of rolling elements 70 are symmetrically arranged along a radial axis of the rotating output element 60, and the two adjacent pairs of rolling elements 70 are symmetrically arranged along another radial axis of the rotating output element 60. For ease of introduction, the symmetry axis of the two adjacent pairs of rolling elements 70 is defined as a first symmetry axis, and the symmetry axis of the two rolling elements 70 in each pair of rolling elements 70 is defined as the first symmetry axis.

[0226] In one embodiment, along the circumference of the rotating output member 60, two adjacent side surfaces 63 are arranged symmetrically about the first symmetry axis. Each side surface 63 is arranged about the second symmetry axis. As a result, the holding forces of the two rolling elements 70 in each pair of rolling elements 70 acting on one side surface 63 are relatively balanced, and the locking forces of the rear wheel steering device 200 provided in the present application on the tie rod 30 of the rear wheel 1002 in the clockwise and counterclockwise directions tend to be consistent. Moreover, the consistency of the torque received by the two adjacent side surfaces 63 when the motor rotates forward and reversely after being radially embedded with the axial protrusion 53 is ensured, thereby ensuring the consistency of the torque transmitted to the tie rod 30 of the rear wheel 1002, which is convenient for controlling the rotation angle of the rear wheel 1002.

[0227] In one embodiment, along the circumference of the rotating output member 60, two adjacent elastic components 80 are symmetrically arranged about the first symmetry axis. The two spring pieces 81 and the U-shaped connecting end 82 in each elastic component 80 are symmetrically arranged about the first symmetry axis. Thus, when the rotating input member 50 rotates clockwise or counterclockwise with the steering motor 10, the two spring pieces 81 of each elastic component 80 are deformed alternately, which can improve the reliability of the elastic component 80 and extend its service life.

[0228] In one embodiment, two opposite circumferential side walls 56 are symmetrically arranged about the second symmetry axis. This facilitates the timing when each axial protrusion 53 contacts multiple pairs of rolling elements 70 to release the locked state of the rotary output element 60 when the rotary input element 50 rotates clockwise, and the timing when each axial protrusion 53 contacts multiple pairs of rolling elements 70 to release the locked state of the rotary output element 60 when the rotary input element 50 rotates counterclockwise, thereby simplifying the control logic of the steering motor 10.

[0229] In one embodiment, along the circumference of the rotating output member 60, two adjacent side surfaces 63 and two adjacent elastic components 80 are arranged symmetrically about the first symmetry axis. The two spring pieces 81 and the U-shaped connecting end 82 in each side surface 63 and each elastic component 80 are arranged symmetrically about the second symmetry axis. Thus, when the rotating input member 50 is not rotating, the holding force of the two rolling elements 70 in each pair of rolling elements 70 acting on one side surface 63 is relatively balanced, and the rear wheel steering device 200 provided in the present application tends to have the same locking force on the tie rod 30 of the rear wheel 1002 in the clockwise and counterclockwise directions. When the rotating input member 50 rotates, it rotates forward and reversely with the steering motor 10 to make the timing of releasing the locking state of the rolling element 70 on the rotating output member 60 the same, thereby simplifying the control logic of the steering motor 10.

[0230] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the scope of protection of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A rear wheel steering gear with locking function, characterized in that: The housing of the rear wheel steering gear is used to accommodate a rotation input member, a rotation output member, multiple pairs of rolling members and multiple elastic components, the transmission end of the rotation input member is used to receive the drive of the vehicle's steering motor, the coupling end of the rotation input member is used to drive the coupling end of the rotation output member, and the transmission end of the rotation output member is used to drive the tie rod of at least one rear wheel in the vehicle, wherein: The coupling end of the one rotating input member comprises a plurality of axial protrusions, the plurality of axial protrusions are spaced around the coupling end of the one rotating output member, and the one rotating output member and each of the axial protrusions are embedded in the radial direction of the rotating output member; The outer peripheral surface of the coupling end of the one rotating output member includes a plurality of side surfaces, and the gap between each of the side surfaces and the housing is used to accommodate a pair of the rolling elements, and two pairs of the rolling elements adjacent to each other along the circumference of the one rotating output member are respectively arranged on both sides of one of the axial protrusions, and the two rolling elements in each pair of the rolling elements are arranged between the two axial protrusions at intervals; Each of the elastic components is used to drive two of the pair of rolling elements to move away from each other and lock the rotation of the one rotating output element during the process of the one rotating input element stopping rotation, and each of the axial protrusions is used to drive the pair of rolling elements to move toward each other and drive the rotation of the one rotating output element during the process of the one rotating input element rotating.

2. The rear wheel steering gear according to claim 1, characterized in that: Each of the axial protrusions comprises a radial groove, and each of the axial protrusions is used to accommodate the angle formed by two adjacent side surfaces through the radial groove so as to be radially embedded in the one rotary output member; or, Each of the axial protrusions includes a radial protrusion, and another radial groove is included between two adjacent side surfaces. Each of the axial protrusions is used to be embedded in the another radial groove through the radial protrusion to be radially embedded in the one rotary output member.

3. The rear wheel steering gear according to claim 2, characterized in that: The included angle between the two groove walls of the radial groove is less than or equal to the included angle formed by the two side surfaces; or, The included angle between the two side walls of the radial protrusion is less than or equal to the included angle between the two groove walls in the other radial groove.

4. The rear wheel steering gear according to any one of claims 1 to 3, characterized in that: Along the circumference of the rotating output member, each of the axial protrusions includes a pair of circumferential side walls, two of the pair of circumferential side walls are used to respectively face two pairs of rolling members arranged on both sides of the axial protrusion, and each of the axial protrusions is used to drive a pair of rolling members to approach each other through a circumferential side wall during the rotation of the rotating input member.

5. The rear wheel steering gear according to claim 4, characterized in that: Along the circumference of the one rotary output member, the sum of the gaps between a pair of circumferential side walls of each axial protrusion and two pairs of rolling members arranged on both sides of the axial protrusion is smaller than the circumferential gap where the axial protrusion is radially embedded with the one rotary output member.

6. The rear wheel steering device according to claim 4 or 5, characterized in that: The two adjacent axial protrusions include two opposite circumferential side walls, which are accommodated in the gap between the same side surface and the inner wall of the shell and arranged on both sides of a pair of rolling elements, and two of the two opposite circumferential side walls are respectively perpendicular to the arrangement direction of two of the pair of rolling elements.

7. The rear wheel steering gear according to claim 6, characterized in that: Along the circumference of the one rotating output member, when the one rotating input member stops rotating, the distance between two of the two opposite circumferential side walls is greater than the width of the pair of rolling members between the two opposite circumferential side walls.

8. The rear wheel steering device according to claim 6 or 7, characterized in that: Along a direction perpendicular to the arrangement direction of two of the pair of rolling elements, a height dimension of two of the two opposite circumferential side walls is greater than or equal to a radius of each of the pair of rolling elements.

9. The rear wheel steering device according to any one of claims 1 to 8, characterized in that: Each of the side surfaces is a plane, each of the side surfaces is symmetrical along the radial axis of the one rotation output member, and two adjacent side surfaces are symmetrically arranged along the radial axis of the one rotation output member.

10. The rear wheel steering gear according to any one of claims 1 to 9, characterized in that: Each of the side surfaces includes a fixing groove, and the notch of each fixing groove faces the inner wall of the shell along the radial direction of the rotating output member. Each fixing groove is used to fix an elastic component, and each elastic component is arranged between two of the rolling elements in a pair of rolling elements along the circumferential direction of the rotating output member.

11. The rear wheel steering device according to any one of claims 1 to 10, characterized in that: Each of the elastic components is a U-shaped spring leaf, which includes two spring leaves and a U-shaped connecting end. The U-shaped connecting end is used to be embedded in the side and to connect the two spring leaves. The two spring leaves are used to respectively abut against two of the pair of rolling elements.

12. The rear wheel steering device according to claim 11, characterized in that: The bending radius of the U-shaped connecting end of the U-shaped spring sheet is smaller than the spacing distance between the two spring sheets; or, The length of each of the elastic sheets exposed from the side surface is greater than the radius of the rolling element abutting against the elastic sheet.

13. The rear wheel steering gear according to any one of claims 1 to 12, characterized in that: The inner wall of the shell is a circumferential surface. When the one rotating input member stops rotating, each elastic component is used to drive two of the pair of rolling members to respectively abut against the inner wall of the shell and the same side surface to lock the rotation of the one rotating output member.

14. The rear wheel steering gear according to any one of claims 1 to 13, characterized in that: Two of the pair of rolling elements are cylindrical, the cylindrical center axis of each rolling element is parallel to the axial direction of the one rotating output element, and the cylindrical diameters of the two rolling elements are equal.

15. A vehicle, characterized in that: The vehicle comprises: one or more rear wheels; and The rear wheel steering gear according to any one of claims 1 to 14, wherein the rear wheel steering gear is used to drive the one or more rear wheels to change direction.

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