CN220910283U - Clutch mechanism, rear wheel steering device and vehicle - Google Patents

Abstract

The utility model provides a clutch mechanism, a rear wheel steering device and a vehicle, wherein the clutch mechanism comprises a clutch cover which rotates synchronously with a rotating piece in the rear wheel steering device, a fixed plate and a first driving part which are fixedly arranged in the rear wheel steering device, and a friction plate arranged on the fixed plate; the clutch cover is provided with a friction surface which is arranged opposite to the friction plate, the first driving part is in transmission connection with the friction plate, and the friction plate can move along the radial direction of the clutch cover under the driving of the first driving part so as to be abutted on the friction surface or be separated from being abutted with the friction surface. The utility model can realize the locking function of the rear wheel steering while adopting the ball screw transmission structure, can improve the steering control capability of the wheels, and is beneficial to improving the use effect of the rear wheel steering.

Description

Clutch mechanism, rear wheel steering device and vehicle

Technical Field

The utility model relates to the technical field of vehicles, in particular to a clutch mechanism. The utility model also relates to a rear wheel steering gear with the clutch mechanism and a vehicle provided with the rear wheel steering gear.

Background

In the prior art, the rear wheel steering device is arranged in the vehicle, so that the turning radius can be reduced when the vehicle turns at a low speed, the turning flexibility can be increased, the turning radius can be increased when the vehicle turns at a high speed, and the stability of the vehicle can be increased. The rear wheel steering gear generally outputs power by an electric signal controlling a motor to drive a rack to move laterally so that a wheel rotates about a kingpin axis to deflect the wheel. Meanwhile, the rear wheel steering device also needs to keep the stability of the rack position after the wheels are stressed, namely has a rotation locking function, but the locking mechanism in the existing rear wheel steering device is structurally complex, has higher failure rate, has lower locking reliability and the like, so that the use effect of the rear wheel steering device can be limited.

Disclosure of utility model

In view of the above, the present utility model aims to provide a clutch mechanism to help to improve the use effect of the rear wheel steering gear.

In order to achieve the above purpose, the technical scheme of the utility model is realized as follows:

A clutch mechanism comprises a clutch cover which rotates synchronously with a rotating piece in a rear wheel steering device, a fixed plate and a first driving part which are fixedly arranged in the rear wheel steering device, and a friction plate arranged on the fixed plate;

The clutch cover is provided with a friction surface which is arranged opposite to the friction plate, the first driving part is in transmission connection with the friction plate, and the friction plate can move along the radial direction of the clutch cover under the driving of the first driving part so as to be abutted on the friction surface or be separated from being abutted with the friction surface.

Further, the friction plate is located inside the clutch cover, and the friction plate is located on the inner wall of the clutch cover.

Further, the friction plate is arranged on the fixed plate through the mounting plate, and the first driving part is in transmission connection with the mounting plate.

Further, the mounting plate is arc-shaped, the friction plate is arranged along the outer edge of the mounting plate, one end of the mounting plate is rotationally connected to the fixing plate, and the first driving part is in transmission connection with the other end of the mounting plate.

Further, the first driving part comprises a linear power output unit arranged in the rear wheel steering device, a connecting plate connected to the power output end of the linear power output unit, and a transmission rod hinged between the connecting plate and the mounting plate.

Further, the linear power output unit comprises a first motor fixedly arranged in the rear wheel steering device, a first lead screw connected to the first motor, and a first lead screw nut slidingly arranged in the rear wheel steering device;

the first lead screw is in threaded connection with the first lead screw nut, and the connecting plate is connected with the first lead screw nut.

Compared with the prior art, the utility model has the following advantages:

The clutch mechanism disclosed by the utility model has the advantages that the clutch cover and the rotating piece in the rear wheel steering device synchronously rotate, the friction surface is arranged, when the first driving part drives the friction plate to be in contact with the friction surface along the radial direction of the clutch cover, the rotation locking of the rear wheel steering device can be realized through locking the clutch cover, when the first driving part drives the friction plate to be in contact with the friction surface along the radial direction of the clutch cover, the locking of the clutch cover, namely the rear wheel steering device, can be released, and the clutch mechanism is only composed of the clutch cover, the friction plate and the first driving part, has a simple structure and low failure rate, and can ensure the locking capability of the friction plate and the rotating piece of the rear wheel steering device by means of contact, and can increase the locking reliability, so that the use effect of the rear wheel steering device is promoted.

Another object of the present utility model is to propose a rear-wheel steering gear having a steering assist mechanism therein, and a clutch mechanism as described above;

The steering power assisting mechanism comprises a second screw nut which is rotatably arranged, a second screw which is in threaded connection with the second screw nut, and a second driving part which is in transmission connection with the second screw nut;

The second screw nut and the second screw form a ball screw nut mechanism, and the second screw nut forms the rotating member.

Further, the second driving part comprises a rotary driving unit and a belt transmission unit arranged between the power output end of the rotary driving unit and the second screw nut.

Further, the rotation driving unit includes a second motor;

the belt transmission unit comprises a first belt pulley connected to the second motor, a second belt pulley connected to the second screw nut, and a belt arranged between the first belt pulley and the second belt pulley.

According to the rear wheel steering device, the ball screw nut mechanism formed by the second screw nut and the second screw is adopted, so that the higher positive transmission efficiency of the ball screw nut mechanism can be utilized, the utilization rate of the output power of the second driving part is increased, the upper limit of the rack force in the rear wheel steering device is improved, and the rear wheel steering device can be adapted to a vehicle type with heavier rear axle load. Meanwhile, by arranging the clutch mechanism, the locking capacity of the rear wheel steering gear can be guaranteed, the locking reliability is improved, and the use effect of the rear wheel steering gear is improved.

The utility model also provides a vehicle, wherein the rear wheel steering device is arranged in the vehicle.

The vehicle of the present utility model has the same advantageous effects as the rear wheel steering apparatus described above with respect to the prior art, and will not be described in detail herein.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model. In the drawings:

FIG. 1 is a schematic diagram of a clutch mechanism according to an embodiment of the present utility model;

FIG. 2 is a schematic view of a portion of a rear-wheel steering apparatus according to an embodiment of the present utility model;

FIG. 3 is a schematic view of a clutch cover according to an embodiment of the present utility model;

FIG. 4 is a schematic view illustrating the arrangement of friction plates on a fixed plate according to an embodiment of the present utility model;

fig. 5 is a schematic structural view of a linear power output unit according to an embodiment of the utility model;

FIG. 6 is a schematic view of a rear-wheel steering wheel portion structure according to an embodiment of the present utility model;

FIG. 7 is an exploded view of the structure shown in FIG. 6;

FIG. 8 is a cross-sectional view taken along the direction A-A in FIG. 6;

Reference numerals illustrate:

1. a clutch cover; 2. a fixing plate; 3. a friction plate; 4. a mounting plate; 5. a hinge shaft; 6. a first driving section; 7. a second lead screw nut; 8. a second lead screw; 9. a second driving section; 10. a bearing; 11. a screw plug; 12. a housing;

1a, friction surface; 2a, a central ring; 601. a first motor; 602. a first lead screw; 603. a first lead screw nut; 604. a transmission rod; 605. a connecting plate; 901. a second motor; 902. a first pulley; 903. a second pulley; 904. a belt.

Detailed Description

It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other.

In the description of the present utility model, it should be noted that, if terms indicating an orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. are presented, they are based on the orientation or positional relationship shown in the drawings, only for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or element to be referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and the like, if any, are also used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Furthermore, in the description of the present utility model, the terms "mounted," "connected," and "connected," are to be construed broadly, unless otherwise specifically defined. For example, the connection can be fixed connection, detachable connection or integrated connection; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art in combination with specific cases.

The utility model will be described in detail below with reference to the drawings in connection with embodiments.

Example 1

The present embodiment relates to a clutch mechanism for use in a rear-wheel steering apparatus in a vehicle to lock rotation of the rear-wheel steering apparatus during the steering of the rear-wheel.

As shown in fig. 1 to 5, the clutch mechanism of the present embodiment includes a clutch cover 1 that rotates in synchronization with a rotating member in a rear wheel steering, a fixed plate 2 and a first driving portion 6 that are fixedly provided in the rear wheel steering, and a friction plate 3 that is provided on the fixed plate 2.

The clutch cover 1 is provided with a friction surface 1a opposite to the friction plate 3, the first driving part 6 is in transmission connection with the friction plate 3, and the friction plate 3 can move along the radial direction of the clutch cover 1 under the driving of the first driving part 6 so as to be abutted against the friction surface 1a or be separated from being abutted against the friction surface 1 a.

In the above configuration, the clutch cover 1 is rotated in synchronization with the rotating member in the rear wheel steering apparatus, the friction surface 1a is provided on the clutch cover 1, and when the first driving portion 6 drives the friction plate 3 to radially abut against the friction surface 1a along the clutch cover 1, the rotation of the clutch cover 1 can be locked, thereby realizing the rotation locking of the rear wheel steering apparatus. When the first driving portion 6 urges the friction plate 3 to come out of contact with the friction surface 1a in the radial direction of the clutch cover 1, the lock of the clutch cover 1, that is, the rear wheel steering device can be released. Thus, the present embodiment can realize the locking function for the rear wheel steering gear.

Based on the above overall description, specifically, still referring to fig. 1 and 3, as a preferred embodiment, the clutch cover 1 of the present embodiment is a cylinder shape with one end partially closed, and the friction surface 1a is specifically located on the inner wall of the clutch cover 1, while the above-mentioned friction plate 3 is also located inside the clutch cover 1 so as to be disposed opposite to the friction surface 1a on the inner wall of the clutch cover 1.

Furthermore, as a preferred embodiment, in combination with the embodiment shown in fig. 2 and 4, the friction plate 3 of the present embodiment may be disposed on the fixed plate 2, for example, by the mounting plate 4, and the first driving portion 6 is specifically in driving connection with the mounting plate 4, so as to achieve driving of the friction plate 3. In this way, the arrangement of the friction plate 3 on the fixed plate 2 is performed by the mounting plate 4, which helps to simplify the structure of the friction plate 3 and can facilitate the arrangement of the friction plate 3.

In this embodiment, based on the installation of the friction plate 3 by using the installation plate 4, in a specific implementation, as a preferred implementation manner, the installation plate 4 may be, for example, arc-shaped, and accordingly, the friction plate 3 is also designed as an arc-shaped plate and is disposed along the outer edge of the installation plate 4, meanwhile, one end of the installation plate 4 is rotationally connected to the fixed plate 2, and the first driving part 6 is in transmission connection with the other end of the installation plate 4.

At this time, one end of the mounting plate 4 is rotatably connected to the fixed plate 2 via the hinge shaft 5, for example, so as to be able to rotate the friction plate 3 about the axis of the hinge shaft 5, so that the friction plate 3 is moved in the radial direction of the clutch cover 1. In addition, the rotation setting of the mounting plate 4 on the fixed plate 2 is realized through the hinge shaft 5, and the device has the advantages of simple structure, convenience in design, manufacture, assembly and the like.

Furthermore, when the mounting plate 4 is designed in an arc shape and the friction plate 3 is arranged along the outer edge of the mounting plate 4, it is preferable that the friction plate 3 and the clutch cover 1 should be arranged concentrically in practice, that is, the friction plate 3 and the friction surface 1a on the inner wall of the clutch cover 1 are made parallel to each other, so that a better friction locking effect can be obtained when the friction plate 3 abuts against the friction surface 1a, and the driving force required when the friction plate 3 is locked can be reduced.

In this embodiment, as further shown in fig. 1 and 2 in combination with fig. 5, the first driving part 6 specifically includes a linear power output unit provided in the rear wheel steering, a connection plate 605 connected to a power output end of the linear power output unit, and a transmission rod 604 hinged between the connection plate 605 and the mounting plate 4.

In particular, as an exemplary embodiment, the linear power output unit may include, for example, a first motor 601 fixed in the rear wheel steering apparatus, a first screw 602 connected to the first motor 601, and a first screw nut 603 slidably provided in the rear wheel steering apparatus. The first screw rod 602 is screwed into the first screw rod nut 603, and the connection plate 605 is connected to the first screw rod nut 603, so that the rotation of the first motor 601 can be converted into the linear motion of the connection plate 605 by using the screw rod nut mechanism composed of the first screw rod 602 and the first screw rod nut 603, and the rotation of the installation plate 4 is driven by the transmission rod 604 hinged between the connection plate 605 and the installation plate 4.

It can be understood that the linear power output unit adopts the screw nut mechanism composed of the first motor 601, the first screw 602 and the first screw nut 603, and has the advantages of stable motion, high transmission efficiency and positioning accuracy, and the like, so that the accurate control of the motion of the friction plate 3 can be realized, and the locking capability of the clutch mechanism is further ensured.

In addition, it should be noted that, in the implementation, the fixing plate 2 may be fixed in the housing 12 of the rear wheel steering apparatus, for example, by a bracket structure fixedly connected to a connecting hole at one end of the fixing plate, the first motor 601 may be fixed in the housing 12 by a conventional mounting structure, and the first screw nut 603 may be slidably disposed in the housing 12 by referring to an existing linear sliding rail structure. Meanwhile, as shown in fig. 4 and 5, the transmission rod 604 and the connecting plate 605, and the transmission rod 604 and the mounting plate 4 are hinged together by conventional shaft pin structures. For example, a fastening hole may be formed on the connection plate 605, and a convex fastening structure may be formed on the first screw nut 603, so that the connection between the connection plate 605 and the first screw nut 603 is achieved by fastening the fastening structure in the fastening hole.

Of course, instead of the above arrangement, the fixing plate 2 may be fixed in the housing 12 in other structures, and the connecting plate 605 may be connected to the first lead screw nut 603 in other connection manners.

In this embodiment, it should be further noted that, in the implementation, the screw nut mechanism formed by the first screw 602 and the first screw nut 603 may be a ball screw nut mechanism, or may be a screw nut mechanism with other structural forms, as long as it can be driven by the first motor 601 to meet the driving requirement on the mounting plate 4.

The clutch mechanism of this embodiment can realize the locking of the rotation of the rear wheel steering device by adopting the above structure, wherein the first driving part 6 drives the friction plate 3 to move along the radial direction of the clutch cover 1, and the clutch mechanism is only composed of the clutch cover 1, the friction plate 3 and the first driving part 6, so that the clutch mechanism has the advantages of simple structure and low failure rate, and simultaneously can ensure the locking capability of the rotating member of the rear wheel steering device by utilizing the contact between the friction plate 3 and the friction surface 1a on the clutch cover 1, thereby increasing the locking reliability and being beneficial to improving the use effect of the rear wheel steering device.

Example two

The present embodiment relates to a rear wheel steering apparatus provided in a vehicle and configured to steer rear wheels according to an electric signal of a vehicle controller (or other control device in the vehicle) to reduce a turning radius when the vehicle turns at a low speed, increase flexibility of turning, and increase the turning radius also when the vehicle turns at a high speed, increase stability of the vehicle, and improve safety of running of the vehicle.

Structurally, the rear-wheel steering of the present embodiment has a steering assist mechanism, and the clutch mechanism of the first embodiment described above.

The steering power assisting mechanism is mainly used for outputting driving force for driving rear wheels of a vehicle to steer, and the driving force is generally used for driving racks in a rear wheel steering device to transversely move, and the rear wheels are enabled to rotate around a king pin axis by the movement of the racks, so that steering control of the rear wheels is achieved.

The clutch mechanism is used for locking the rotation of the rear wheel steering device in the process of driving the rear wheel steering, so as to ensure the reliability of the steering control of the rear wheel and ensure the running safety of the vehicle. In addition, in the rear wheel steering device, generally, when the steering power assisting mechanism drives the rear wheel to steer through the rack, the movement direction of the rack can be regarded as forward, accordingly, in order to keep the position of the rear rack stable after the rear wheel steering, the rack needs to be prevented from moving reversely through the locking of the clutch mechanism, so the locking function of the clutch mechanism in the rear wheel steering device in the embodiment can be called a reverse locking function.

Based on the above description, in the present embodiment, as shown in fig. 6 to 8, the above-described steering assist mechanism specifically includes the second lead screw nut 7 rotatably provided, the second lead screw 8 screwed in the second lead screw nut 7, and the second drive portion 9 drivingly connected to the second lead screw nut 7. The second screw nut 7 and the second screw 8 constitute a ball screw nut mechanism, and the second screw nut 7 also specifically constitutes a rotating member that rotates in synchronization with the clutch cover 1 in the first embodiment.

At this time, by making the second screw nut 7 and the second screw 8 constitute a ball screw nut mechanism, it is possible to increase the utilization ratio of the output power of the second driving portion 9 by utilizing the high positive transmission efficiency (generally, 95% or more) of the ball screw nut mechanism, so as to increase the upper limit of the rack force in the rear wheel steering, so that the rear wheel steering can be adapted to a vehicle type with a heavier rear axle load.

Further, as a preferred embodiment, the second driving part 9 of the present embodiment includes a rotation driving unit and a belt transmission unit provided between a power output end of the rotation driving unit and the second lead screw nut 7.

Wherein further, the above-mentioned rotary driving unit may preferably comprise a second motor 901, and the above-mentioned belt transmission unit may preferably comprise a first pulley 902 connected to the second motor 901, a second pulley 903 connected to the second lead screw nut 7, and a belt 904 disposed between the first pulley 902 and the second pulley 903. Meanwhile, in practice, the diameter of the first pulley 902 should also be generally set smaller than that of the second pulley 903.

It can be appreciated that the second driving portion 9 in this embodiment adopts a driving form formed by the second motor 901 and the belt transmission unit, which has the advantages of simple and reliable structure, high transmission efficiency, capability of alleviating impact and vibration, and capability of reducing vibration and noise. Of course, besides adopting a belt transmission mode, in the concrete implementation, transmission connection between the second motor 901 and the second screw nut 7 can be realized through other conventional transmission structures, so that the rack in the rear wheel steering device can be driven to move through the second screw 8 under the driving of the second motor 901, and finally steering driving of the rear wheels of the vehicle is realized.

As still shown in fig. 6 to 8, it is noted that the steering assist mechanism and the clutch mechanism described above of the present embodiment may be provided on the housing 12 of the rear wheel steering, as mentioned in the first embodiment. In this case, the construction of the housing 12 is based on the above construction of the steering assist mechanism and the clutch mechanism, as shown in fig. 6 and 7, and the bearing 10 can be mounted on the second spindle nut 7, for example, while the outer ring of the bearing 10 is fixed in the housing 12 by the screw plug 11, in order to thereby realize a rotational arrangement of the second spindle nut 7 in the housing 12.

In particular, the clutch cover 1 may be fastened to the end of the second lead screw nut 7 by a plurality of through holes, or the clutch cover 1 and the second lead screw nut 7 may be fastened together by interference press-fitting. The center of the fixing plate 2 may be provided with a center ring 2a, for example, and when the fixing plate 2 is assembled in the rear wheel steering apparatus as shown in fig. 8, the center ring 20 may be sleeved outside the second screw shaft 8 in the rear wheel steering apparatus, thereby improving the stability of the fixing plate 2 and the second screw shaft 8 in the housing 12.

In the belt transmission unit constituted by the first pulley 902, the second pulley 903, and the belt 904, each pulley and the belt 904 may be a conventional mature product. The connection between the second lead screw 8 and the rack in the rear-wheel steering device in this embodiment and the driving of the second lead screw 8 drive the rear wheel to steer through the rack, which is also all the related structures in the existing rear-wheel steering device.

When the rear wheel steering device of the embodiment is in operation and the rear wheel of the vehicle is required to be controlled to steer, the vehicle controller controls the second motor 901 to rotate, the second motor 901 drives the second lead screw nut 7 to rotate through the belt transmission unit, and the second lead screw 8 is connected with the rack in the rear wheel steering device, so that the rotational freedom degree of the second lead screw 8 is limited, the second lead screw nut 7 can rotate to enable the second lead screw 8 to move along the axis of the second lead screw nut, and the rack can be driven to steer the rear wheel.

Under the control of a vehicle controller, after the rear wheel rotates to a preset angle through the driving of the second motor 901, the second motor 901 can be stopped, the first motor 601 is controlled to rotate, and under the driving of the first motor 601, the friction plate 3 moves radially along the clutch cover 1 and is abutted on the friction surface 1a of the clutch cover 1, so that a locking effect can be achieved on racks in the rear wheel steering device, and the reliability of the steering control of the rear wheel is guaranteed.

The rear wheel steering device of this embodiment adopts ball screw nut mechanism, and the multiplicable utilization ratio to second motor 901 output can make the heavier motorcycle type of rear wheel steering device adaptation rear axle load, and simultaneously, it also can cooperate ball screw nut mechanism through adopting clutch mechanism, guarantees the locking ability of rear wheel steering device, helps promoting the result of use of rear wheel steering device, and has fine practicality.

Example III

The present embodiment relates to a vehicle in which the rear wheel steering apparatus of the second embodiment is provided.

The vehicle of this embodiment sets up the vehicle rear wheel steering ware in the embodiment two, can promote the transmission efficiency of second motor 901 in the rear wheel steering ware, increases the helping hand ability of second motor 901 for rear wheel steering ware adaptation rear axle load heavier motorcycle type also can guarantee simultaneously to the locking ability of rear wheel steering ware, helps promoting the result of use of rear wheel steering ware, and has fine practicality.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the utility model.

Claims (10)

1. A clutch mechanism, characterized in that:

Comprises a clutch cover (1) which rotates synchronously with a rotating piece in a rear wheel steering device, a fixed plate (2) and a first driving part (6) which are fixedly arranged in the rear wheel steering device, and a friction plate (3) arranged on the fixed plate (2);

The clutch cover (1) is provided with a friction surface (1 a) which is arranged opposite to the friction plate (3), the first driving part (6) is in transmission connection with the friction plate (3), and under the driving of the first driving part (6), the friction plate (3) can move along the radial direction of the clutch cover (1) so as to be abutted to the friction surface (1 a) or be separated from the abutting joint of the friction surface (1 a).

2. The clutch mechanism according to claim 1, wherein:

The friction plate (3) is positioned inside the clutch cover (1), and the friction surface (1 a) is positioned on the inner wall of the clutch cover (1).

3. The clutch mechanism according to claim 2, wherein:

The friction plate (3) is arranged on the fixed plate (2) through the mounting plate (4), and the first driving part (6) is in transmission connection with the mounting plate (4).

4. A clutch mechanism according to claim 3, wherein:

The mounting plate (4) is arc-shaped, the friction plate (3) is arranged along the outer edge of the mounting plate (4), one end of the mounting plate (4) is rotationally connected to the fixed plate (2), and the first driving part (6) is in transmission connection with the other end of the mounting plate (4).

5. The clutch mechanism according to claim 4, wherein:

The first driving part (6) comprises a linear power output unit arranged in the rear wheel steering device, a connecting plate (605) connected to the power output end of the linear power output unit, and a transmission rod (604) hinged between the connecting plate (605) and the mounting plate (4).

6. The clutch mechanism according to claim 5, wherein:

The linear power output unit comprises a first motor (601) fixedly arranged in the rear wheel steering device, a first lead screw (602) connected to the first motor (601), and a first lead screw nut (603) slidingly arranged in the rear wheel steering device;

the first screw (602) is screwed into a first screw nut (603), and the connecting plate (605) is connected to the first screw nut (603).

7. A rear wheel steering gear, characterized in that:

the rear wheel steering apparatus having therein a steering assist mechanism, and the clutch mechanism of any one of claims 1 to 6;

The steering power assisting mechanism comprises a second screw nut (7) which is rotatably arranged, a second screw (8) which is in threaded connection with the second screw nut (7), and a second driving part (9) which is in transmission connection with the second screw nut (7);

The second screw nut (7) and the second screw (8) form a ball screw nut mechanism, and the second screw nut (7) forms the rotating member.

8. The rear wheel steering apparatus according to claim 7, wherein:

The second driving part (9) comprises a rotary driving unit and a belt transmission unit arranged between the power output end of the rotary driving unit and the second screw nut (7).

9. The rear wheel steering apparatus according to claim 8, wherein:

the rotary drive unit comprises a second motor (901);

The belt drive unit comprises a first pulley (902) connected to the second motor (901), a second pulley (903) connected to the second lead screw nut (7), and a belt (904) arranged between the first pulley (902) and the second pulley (903).

10. A vehicle, characterized in that:

the rear wheel steering apparatus according to any one of claims 7 to 9 is provided in the vehicle.