Steering transmission shaft

Abstract

A steering transmission shaft, which relates to the technical field of vehicles. The transmission shaft comprises: a first shaft assembly (01), a second shaft assembly (02), and a third shaft assembly (03). The second shaft assembly comprises an outer sleeve unit (21), an intermediate sleeve unit (22), and an inner sleeve unit (23). The outer sleeve unit comprises an outer sleeve module (211), an outer limiting groove (212), and an outer snap spring (213). The intermediate sleeve unit comprises an intermediate sleeve module (221), an intermediate boss (227), an intermediate snap spring (229), and an intermediate limiting groove (226). The outer sleeve module is sleeved over an outer peripheral side of the intermediate sleeve module. The intermediate sleeve module comprises an intermediate torsion portion (2211) and an intermediate side wall (2212). The inner sleeve unit comprises an inner sleeve module (231) and an inner boss (232). The intermediate sleeve module is sleeved over an outer peripheral side of the inner sleeve module. The steering transmission shaft comprises an extended state. The extended state comprises a state in which the intermediate boss moves in the axial direction of the outer sleeve module to abut against the end of the outer snap spring close to the first shaft assembly, the resistance of the intermediate snap spring to the inner boss is greater than the friction force between the intermediate side wall and the outer sleeve module, and the inner boss is disposed inside a space enclosed by the intermediate snap spring. The steering transmission shaft solves the problem of how to prolong the service life of the steering transmission shaft.

Description

A steering drive shaft Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically, to a steering drive shaft. Background Technology

[0002] The primary function of the steering drive shaft is to transmit the force and motion output from the steering gear to the universal joints, thereby achieving the steering motion of the wheels. Simultaneously, it can transmit a certain amount of torque to ensure that the vehicle can smoothly and accurately follow the driver's intentions during steering. A steering drive shaft typically consists of two universal joints, an outer spline sleeve, an intermediate spline sleeve, and an inner spline sleeve. The outer spline sleeve can be fitted onto the outer circumference of the intermediate spline sleeve, and the intermediate spline sleeve can be fitted onto the outer circumference of the inner spline sleeve. One universal joint connects to one end of the outer spline sleeve, and the other universal joint connects to one end of the inner spline sleeve.

[0003] The steering drive shaft connects the steering wheel at one end and the steering gear at the other. During vehicle use, the steering drive shaft needs to extend or shorten. For example, the vehicle's wheels moving up and down with the road surface will cause the steering drive shaft to extend or shorten, as will adjusting the steering wheel height. In heavy trucks, for instance, during maintenance, the cab needs to be tilted. This tilting increases the distance between the steering wheel and the steering gear, causing the steering drive shaft to extend or shorten accordingly. The inner spline sleeve may move relative to the outer spline sleeve and the intermediate spline sleeve. Because the inner spline sleeve has a smaller diameter, it is more easily damaged under certain forces than the larger diameter outer spline sleeve, reducing its service life and strength. This affects the load-bearing capacity of the steering drive shaft, thereby reducing the vehicle's steering stability and driving safety. Summary of the Invention

[0004] To address the problem of improving the lifespan of steering drive shafts, this invention provides a steering drive shaft, comprising:

[0005] First axis assembly;

[0006] The second shaft assembly includes an outer sleeve unit, a middle sleeve unit, and an inner sleeve unit. The outer sleeve unit includes an outer sleeve module, an outer limiting groove, and an outer retaining spring. The outer sleeve module is a tubular body. The outer sleeve module is detachably connected to the first shaft assembly. The outer limiting groove extends from the inner peripheral wall of the outer sleeve module toward the outer peripheral wall of the outer sleeve module. The outer retaining spring is detachably connected to the inner peripheral wall of the outer sleeve module on the side away from the first shaft assembly.

[0007] The middle sleeve unit includes a middle sleeve module, a middle boss, a middle retaining spring, and a middle limiting groove; the outer sleeve module is sleeved on the outer periphery of the middle sleeve module; the middle sleeve module includes a middle torsion part and a middle sidewall; the middle torsion part and the middle sidewall surround to form a tubular body; one end of the middle torsion part is fixedly connected to the middle sidewall, and the other end extends toward the outer limiting groove; the middle torsion part is disposed in the outer limiting groove; the middle boss is detachably connected to the outer periphery of the middle sleeve module near the outer limiting groove; the middle boss is disposed on the side of the middle sleeve module near the first shaft assembly; the middle retaining spring and the middle sleeve module... The inner peripheral wall of the block is detachably connected; the central retaining spring is disposed on the central sleeve module near the first shaft assembly; the central limiting groove extends from the inner peripheral wall of the central side wall toward the central torsion portion; the inner sleeve unit includes an inner sleeve module and an inner boss; the central sleeve module is sleeved on the outer peripheral side of the inner sleeve module; the inner sleeve module includes an inner torsion portion and an inner side wall; one end of the inner torsion portion is fixedly connected to the inner side wall, and the other end extends toward the central sleeve module; the inner torsion portion is disposed in the central limiting groove; the inner boss is detachably connected to the outer peripheral wall of the inner sleeve module near the first shaft assembly;

[0008] The third axis assembly is detachably connected to the end of the inner sleeve module away from the first axis assembly.

[0009] The steering drive shaft includes an extended state; the extended state includes the middle boss moving axially along the outer casing module to abut against the end of the outer retaining spring near the first shaft assembly, the resistance of the middle retaining spring to the inner boss being greater than the frictional force between the middle sidewall and the outer casing module, and the inner boss being disposed within the space surrounded by the middle retaining spring.

[0010] In some embodiments, the outer casing module includes an outer torsion portion and an outer side wall; the outer torsion portion and the outer side wall surround each other to form a tubular body; one end of the outer torsion portion is fixedly connected to the outer side wall, and the other end extends away from the outer side wall; the outer limiting groove extends from the inner peripheral wall of the outer side wall toward the outer torsion portion; the outer limiting groove is adapted to the outer torsion portion; the plane of symmetry of the outer limiting groove along the circumference of the outer side wall coincides with the plane of symmetry of the outer torsion portion along the circumference of the outer side wall; the radial dimension of the outer limiting groove along the outer side wall is larger than the radial dimension of the outer side wall.

[0011] In some embodiments, the middle sleeve module further includes a middle weight reduction hole; the middle weight reduction hole penetrates radially through the middle sidewall and extends away from the middle torsion portion on the side of the middle sidewall.

[0012] In some embodiments, 0 < A ≤ 0.8B; where A is the circumferential dimension of the central weight-reducing hole along the central sidewall, and B is the circumferential dimension of the central torsion portion near the outer limiting groove along the central sidewall.

[0013] In some embodiments, a plurality of the central torsion portions are arranged circumferentially spaced along the central sidewall; the outer limiting groove is arranged correspondingly to the central torsion portions.

[0014] In some embodiments, the weight-reducing holes on two adjacent central torsion portions are spaced apart axially along the central sidewall.

[0015] In some embodiments, the middle sleeve unit further includes a stop block; the stop block is detachably connected to the inner peripheral wall of the middle sleeve module; the stop block is disposed on the middle sleeve module on a side away from the first shaft assembly;

[0016] The middle sleeve module also includes a mounting hole; the mounting hole penetrates the middle sleeve module radially along the middle sidewall; the movement trajectory of part of the inner boss is within the area projected by the mounting hole toward the inner sleeve module.

[0017] In some embodiments, the mounting hole and the weight reduction hole on the adjacent central torsion portion are axially spaced along the central sidewall.

[0018] In some embodiments, the inner sleeve module further includes an inner weight-reducing hole; the inner weight-reducing hole penetrates radially through the inner sidewall on the side of the inner torsion portion away from the inner sidewall.

[0019] In some embodiments, 0 < D ≤ 0.7E; where D is the circumferential dimension of the inner weight-reducing hole along the inner sidewall, and E is the circumferential dimension of the inner torsion portion near the outer limiting groove along the inner sidewall.

[0020] To address the problem of how to improve the lifespan of steering drive shafts, this invention offers the following advantages:

[0021] The steering drive shaft may include a first shaft assembly, a second shaft assembly, and a third shaft assembly. The second shaft assembly may include an outer sleeve unit, a middle sleeve unit, and an inner sleeve unit. The outer sleeve unit may include an outer sleeve module, an outer limiting groove, and an outer retaining ring. The middle sleeve unit may include a middle sleeve module, a middle boss, a middle retaining ring, and a middle limiting groove. The middle sleeve module may include a middle torsion portion and a middle sidewall. The middle boss may be located on the side of the middle sleeve module closer to the first shaft assembly, so that when the outer sleeve module moves relative to the middle sleeve module towards the first shaft assembly, the middle boss can move into the space surrounded by the outer retaining ring, thereby engaging with the outer retaining ring and fixing the relative position of the middle sleeve unit and the outer sleeve unit. The middle boss can move away from the first shaft assembly towards the outer retaining ring, increasing the distance between the first shaft assembly and the third shaft assembly. The inner sleeve unit may include an inner sleeve module and an inner boss. The inner sleeve module may include an inner torsion portion and an inner sidewall. The inner boss can cooperate with the middle retaining ring to control the relative movement of the middle sleeve unit and the inner sleeve unit. The steering drive shaft may include an extended state. The extended state can include the central boss moving axially along the outer sleeve module from a position spaced apart from the outer retaining spring until it abuts against the end of the outer retaining spring near the first shaft assembly. The resistance of the central retaining spring to the inner boss is greater than the friction between the central sidewall and the outer sleeve module, and the inner boss is within the space enclosed by the central retaining spring. This allows the inner and central sleeve units to remain relatively fixed during vehicle use when the distance between the first and third shaft assemblies increases, while the outer sleeve unit moves relative to both the inner and central sleeve units. Because the outer sleeve unit has a larger diameter, it can withstand greater forces, making the steering drive shaft less prone to damage and improving its strength after stretching. This addresses the issue of extending the lifespan of the steering drive shaft. Attached Figure Description

[0022] Figure 1 shows a schematic diagram of a steering drive shaft according to one embodiment;

[0023] Figure 2 shows a schematic diagram of a second shaft assembly according to one embodiment;

[0024] Figure 3 shows a schematic diagram of the second shaft assembly according to another embodiment;

[0025] Figure 4 shows a schematic diagram of a steering drive shaft according to another embodiment;

[0026] Figure 5 shows a partial schematic diagram of the outer jacket unit according to one embodiment;

[0027] Figure 6 shows a schematic diagram of an outer jacket unit according to one embodiment;

[0028] Figure 7 shows a partial schematic diagram of a middle sleeve unit according to an embodiment;

[0029] Figure 8 shows a partial schematic diagram of the middle sleeve unit in another embodiment;

[0030] Figure 9 shows a partial schematic diagram of the middle sleeve unit in another embodiment;

[0031] Figure 10 shows a partial schematic diagram of an inner sleeve unit according to an embodiment;

[0032] Figure 11 shows a schematic diagram of an inner sleeve unit according to an embodiment;

[0033] Figure 12 shows a schematic diagram of the inner sleeve unit according to another embodiment.

[0034] Reference numerals: 01 First shaft assembly; 02 Second shaft assembly; 21 Outer sleeve unit; 211 Outer sleeve module; 2111 Outer torsion part; 2112 Outer side wall; 212 Outer limiting groove; 213 Outer retaining ring; 22 Middle sleeve unit; 221 Middle sleeve module; 2211 Middle torsion part; 2212 Middle side wall; 2213 Mounting hole; 2214 Middle weight reduction hole; 226 Middle limiting groove; 227 Middle boss; 228 Stop block; 229 Middle retaining ring; 23 Inner sleeve unit; 231 Inner sleeve module; 2311 Inner torsion part; 2312 Inner side wall; 2313 Inner weight reduction hole; 2314 Inner weight reduction groove; 232 Inner boss; 03 Third shaft assembly. Detailed Implementation

[0035] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0036] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0037] The steering drive shaft may stretch or shorten under various conditions, such as when the vehicle wheels move up and down with the road surface, when adjusting the steering wheel height, or when performing cab maintenance on heavy trucks. This can cause the inner spline sleeve to move relative to the outer spline sleeve and intermediate spline sleeve. Because the inner spline sleeve has a smaller diameter, it is more susceptible to damage under certain forces compared to the outer spline sleeve with a larger diameter, thus reducing its service life, decreasing the strength of the spline sleeve, affecting the load-bearing capacity of the steering drive shaft, and consequently reducing the vehicle's steering stability and driving safety. To address the issue of improving the lifespan of the steering drive shaft, this embodiment provides a steering drive shaft, as shown in Figure 1, which may include a first shaft assembly 01, a second shaft assembly 02, and a third shaft assembly 03.

[0038] As shown in Figure 4, the second shaft assembly 02 may include an outer sleeve unit 21, a middle sleeve unit 22, and an inner sleeve unit 23. As shown in Figure 6, the outer sleeve unit 21 may include an outer sleeve module 211, an outer limiting groove 212, and an outer retaining ring 213. As shown in Figure 5, the outer sleeve module 211 may be tubular, thus making it hollow and providing sufficient space to install the middle sleeve unit 22 and the inner sleeve unit 23. The outer sleeve module 211 can be detachably connected to the first shaft assembly 01, facilitating its disassembly and installation. The outer limiting groove 212 extends from the inner peripheral wall of the outer sleeve module 211 toward its outer peripheral wall, and can be used to cooperate with the middle sleeve unit 22 to transmit torque. The outer retaining ring 213 can be detachably connected to the inner peripheral wall of the outer sleeve module 211 away from the first shaft assembly 01, facilitating its disassembly and connection, and allowing for individual replacement of the outer retaining ring 213 when maintenance is required. The outer retaining ring 213 can be used to cooperate with the middle sleeve unit 22 to control the relative movement of the outer sleeve unit 21 and the middle sleeve unit 22.

[0039] The middle sleeve unit 22 may include a middle sleeve module 221, a middle boss 227, a middle retaining spring 229, and a middle limiting groove 226. The outer sleeve module 211 can be fitted onto the outer periphery of the middle sleeve module 221, facilitating movement of the outer sleeve module 211 relative to the middle sleeve module 221. The middle sleeve module 221 may include a middle torsion portion 2211 and a middle sidewall 2212. The middle torsion portion 2211 and the middle sidewall 2212 can surround each other to form a tubular body, allowing the middle sleeve module 221 to be hollow, providing sufficient space for installing the inner sleeve unit 23. One end of the middle torsion portion 2211 can be fixedly connected to the middle sidewall 2212, improving the structural strength of the middle sleeve module 221 and preventing deformation or damage. The other end of the middle torsion portion 2211 can extend towards the outer limiting groove 212, and the middle torsion portion 2211 can be disposed within the outer limiting groove 212. The first shaft assembly 01 drives the outer side wall 2112 and the outer limiting groove 212 to rotate. The middle torsion part 2211, which is set in the outer limiting groove 212, can rotate with the outer side wall 2112, thereby driving the middle side wall 2212 to rotate. The middle boss 227 and the outer peripheral wall of the middle sleeve module 221 near the outer limiting groove 212 can be detachably connected, which facilitates the disassembly and installation of the middle boss 227. When maintenance is required, the middle boss 227 can be replaced separately. The central boss 227 can be positioned on the side of the central sleeve module 221 near the first shaft assembly 01. When the outer sleeve module 211 moves relative to the central sleeve module 221 towards the first shaft assembly 01, the central boss 227 can move into the space enclosed by the outer retaining spring 213, thereby engaging with the outer retaining spring 213 and fixing the relative position of the central sleeve unit 22 and the outer sleeve unit 21. The central boss 227 can also move towards the outer retaining spring 213 away from the first shaft assembly 01, increasing the distance between the first shaft assembly 01 and the third shaft assembly 03. The central retaining spring 229 can be detachably connected to the inner peripheral wall of the central sleeve module 221, facilitating its removal and installation. The central retaining spring 229 can be positioned on the side of the central sleeve module 221 near the first shaft assembly 01. The central limiting groove 226 extends from the inner peripheral wall of the central side wall 2212 towards the central torsion portion 2211. The central limiting groove 226 can be used to cooperate with the inner sleeve unit 23 to transmit torque. As shown in Figure 10, the inner sleeve unit 23 may include an inner sleeve module 231 and an inner boss 232. The middle sleeve module 221 may be sleeved on the outer periphery of the inner sleeve module 231 to facilitate the movement of the middle sleeve module 221 relative to the inner sleeve module 231. The inner sleeve module 231 may include an inner torsion portion 2311 and an inner sidewall 2312.One end of the inner torsion part 2311 can be fixedly connected to the inner sidewall 2312, and the other end can extend towards the middle sleeve module 221. The inner torsion part 2311 can be disposed in the middle limiting groove 226, which can be used for guidance. The first shaft assembly 01 drives the outer sidewall 2112 and the outer limiting groove 212 to rotate. The middle torsion part 2211 disposed in the outer limiting groove 212 can rotate with the outer sidewall 2112, thereby driving the middle limiting groove 226 and the middle sidewall 2212 to rotate. The inner torsion part 2311 disposed in the middle limiting groove 226 can rotate with the middle sidewall 2212, thereby driving the inner sidewall 2312 to rotate. The inner boss 232 can be detachably connected to the outer peripheral wall of the inner sleeve module 231 near the first shaft assembly 01, so that the inner boss 232 can be freely disassembled and installed, and can be replaced separately when maintenance is required. The inner boss 232 can be used to cooperate with the middle retaining spring 229 to control the relative movement of the middle sleeve unit 22 and the inner sleeve unit 23.

[0040] The third shaft assembly 03 and the inner sleeve module 231 can be detachably connected at the end away from the first shaft assembly 01, facilitating the disassembly and installation of the third shaft assembly 03. The outer retaining spring 213 may have an opening at the end near the first shaft assembly 01, allowing the central boss 227 to enter or exit the space enclosed by the outer retaining spring 213 through the opening. The central retaining spring 229 may have an opening at the end away from the first shaft assembly 01, allowing the inner boss 232 to enter or exit the space enclosed by the central retaining spring 229 through the opening.

[0041] The steering drive shaft may include an extended state. In the extended state, a central boss 227 may move axially along the outer sleeve module 211 from a position spaced apart from the outer retaining spring 213 until it abuts against the end of the outer retaining spring 213 near the first shaft assembly 01. The resistance of the central retaining spring 229 to the inner boss 232 is greater than the friction between the central sidewall 2212 and the outer sleeve module 211. The inner boss 232 is positioned within the space enclosed by the central retaining spring 229. This allows the inner sleeve unit 23 and the central sleeve unit 22 to be relatively fixed when the distance between the first shaft assembly 01 and the third shaft assembly 03 increases during vehicle use. The outer sleeve unit 21 can move relative to the inner sleeve unit 23 and the central sleeve unit 22, respectively. Because the outer sleeve unit 21 has a larger diameter, it can withstand greater forces, making the steering drive shaft less prone to damage and increasing its strength after stretching, thereby extending its lifespan.

[0042] In other embodiments, the central limiting groove 226 can be adapted to the central torsion portion 2211. The symmetrical plane of the central limiting groove 226 along the circumference of the central sidewall 2212 can coincide with the symmetrical plane of the central torsion portion 2211 along the circumference of the central sidewall 2212. The radial dimension of the central limiting groove 226 along the central sidewall 2212 can be larger than the radial dimension of the central sidewall 2212. In this way, the weight of the steering drive shaft can be reduced. The inner torsion portion 2311 can surround the inner sidewall 2312 to form a tubular body, making the inner sleeve module 231 hollow to reduce weight and improve vehicle performance. Multiple inner torsion portions 2311 can be evenly spaced along the circumference of the inner sidewall 2312. The central limiting grooves 226 can be arranged corresponding to the number and position of the inner torsion portions 2311. This method strengthens the steering drive shaft and ensures a balanced mass distribution during rotation, preventing vibration and noise caused by uneven mass distribution. The interaction of multiple central limiting grooves 226 with the inner torsion portions 2311 helps disperse the force. As shown in Figure 12, the inner sleeve module 231 can also include an inner weight-reducing groove 2314, which extends from the inner circumferential wall of the inner sidewall 2312 towards the inner torsion portions 2311, thereby reducing the weight of the inner sleeve module 231. As shown in Figure 3, the outer retaining spring 213 can be located on the side of the inner circumferential wall of the outer torsion portion 2111 away from the middle sleeve module 221. The outer retaining spring 213, being away from the central axis of the inner sleeve module 231, bears less torque and strengthens the outer sleeve unit 21. As shown in Figure 9, the central boss 227 can be set on the side of the central torsion part 2211 away from the inner sleeve module 231. The central boss 227 is far from the central axis of the inner sleeve module 231, and bears less torque, which can strengthen the strength of the central sleeve unit 22.

[0043] In some embodiments, the outer casing module 211 may include an outer torsion portion 2111 and an outer side wall 2112. The outer torsion portion 2111 and the outer side wall 2112 can surround each other to form a tubular body, making the outer casing module 211 hollow to reduce weight and provide sufficient space for installing the middle sleeve unit 22 and the inner sleeve unit 23. One end of the outer torsion portion 2111 can be fixedly connected to the outer side wall 2112, and the other end of the outer torsion portion 2111 can extend away from the outer side wall 2112. The outer limiting groove 212 can extend from the inner peripheral wall of the outer side wall 2112 toward the outer torsion portion 2111, so that the outer limiting groove 212 can be used to cooperate with the middle sleeve unit 22. The outer limiting groove 212 can be adapted to the outer torsion portion 2111 to transmit torque. The outer limiting groove 212 can coincide with the circumferential plane of symmetry of the outer side wall 2112 along the circumferential plane of symmetry of the outer torsion portion 2111 along the circumferential plane of symmetry of the outer side wall 2112. The radial dimension of the outer limiting groove 212 along the outer side wall 2112 can be larger than the radial dimension of the outer side wall 2112. In this way, the outer casing module 211 can have sufficient structural strength and reduce the wall thickness of part of the outer casing module 211 to achieve weight reduction.

[0044] In other embodiments, the outer casing module 211 may also include an external weight-reducing hole. The external weight-reducing hole may extend radially through the outer torsion portion 2111 away from the outer wall 2112, thereby reducing the weight of the outer casing module 211.

[0045] In some embodiments, as shown in FIG8, the middle sleeve module 221 may further include a middle weight-reducing hole 2214. The middle weight-reducing hole 2214 may penetrate radially through the middle torsion portion 2211 on the side away from the middle sidewall 2212. Since the side of the middle torsion portion 2211 away from the middle sidewall 2212 is far from the central axis of the inner sleeve module 231, and the torque is transmitted between the outer sleeve module 211, the middle sleeve module 221 and the inner sleeve module 231 through the middle torsion portion 2211 along both sides of the middle sidewall 2212 in the circumferential direction, this arrangement can reduce the weight of the middle sleeve module 221 while ensuring the strength of the middle sleeve module 221.

[0046] In some embodiments, the dimension A of the central weight reduction hole 2214 along the circumferential direction of the central sidewall 2212 can be greater than 0 and less than or equal to 0.8 times the dimension B of the central torsion portion 2211 along the circumferential direction of the central sidewall 2212 near the outer limiting groove 212. Within this range, the weight of the central sleeve module 221 can be reduced to improve vehicle working efficiency while ensuring the strength of the central sleeve module 221. This avoids the central sleeve module 221 being too large, which would affect its strength, and the central sleeve module 221 being too small, which would affect its weight reduction effect.

[0047] In other embodiments, the dimension C of the central weight-reducing hole 2214 along the axial direction of the central sidewall 2212 can be 4 to 5 times the dimension A of the central weight-reducing hole 2214 along the circumferential direction of the central sidewall 2212. Within this range, the weight of the central sleeve module 221 can be further effectively reduced while ensuring the strength of the central sleeve module 221.

[0048] In some embodiments, a plurality of intermediate torsion portions 2211 may be arranged circumferentially along the intermediate sidewall 2212, and an outer limiting groove 212 may be arranged corresponding to the intermediate torsion portions 2211. The outer limiting groove 212 may cooperate with the intermediate torsion portions 2211 to transmit torque. In this way, the cooperation of multiple sets of intermediate torsion portions 2211 and outer limiting grooves 212 can disperse the force and strengthen the strength of the intermediate sleeve module 221, thereby strengthening the strength of the steering drive shaft.

[0049] In other embodiments, multiple intermediate torsion portions 2211 can be evenly spaced along the circumference of the intermediate sidewall 2212, and the outer limiting groove 212 can be configured in accordance with the number and position of the intermediate torsion portions 2211, so that the mass distribution of the steering drive shaft can be as balanced as possible when the steering drive shaft rotates, so as to avoid vibration and noise caused by uneven mass distribution.

[0050] In some embodiments, the weight reduction holes 2214 on two adjacent intermediate torsion portions 2211 can be spaced apart along the axial direction of the intermediate sidewall 2212 to avoid excessive weakening of the material in a local area of ​​the intermediate torsion portion 2211, thereby improving the overall structural strength of the intermediate sleeve module 221, improving the heat dissipation performance of the intermediate sleeve module 221, and increasing the service life of the intermediate sleeve module 221.

[0051] In some embodiments, as shown in FIG7, the middle sleeve unit 22 may further include a stop 228. The stop 228 is detachably connected to the inner peripheral wall of the middle sleeve module 221, facilitating the installation and removal of the stop 228. The stop 228 may be disposed on the side of the middle sleeve module 221 away from the first shaft assembly 01. The stop 228 may be used to limit movement, preventing the second shaft assembly 02 from exceeding its range of motion and protecting the second shaft assembly 02 from damage. When the inner boss 232 abuts against the stop 228, the resistance of the stop 228 to the inner boss 232 allows the middle boss 227 to move into the space surrounded by the outer retaining spring 213, thereby engaging with the outer retaining spring 213 and fixing the relative position of the outer sleeve unit 21 and the middle sleeve unit 22.

[0052] As shown in Figure 2, the middle sleeve module 221 may also include a mounting hole 2213. The mounting hole 2213 can penetrate the middle sleeve module 221 radially along the middle sidewall 2212, and the movement trajectory of part of the inner boss 232 is within the area projected by the mounting hole 2213 onto the inner sleeve module 231. Since a middle retaining spring 229 is installed on the side of the middle sleeve module 221 closest to the first shaft assembly 01, and a stop block 228 is installed on the side of the middle sleeve module 221 away from the first shaft assembly 01, when the inner sleeve module 231 with the inner boss 232 is inserted into the middle sleeve module 221 axially, it will be blocked and cannot be assembled. Therefore, the mounting hole 2213 allows the inner sleeve module 231 to be inserted into the middle sleeve module 221 axially, and then the inner boss 232 is connected to the outer peripheral wall of the inner sleeve module 231 through the mounting hole 2213, thereby realizing the smooth installation of the inner sleeve module 231 into the middle sleeve module 221.

[0053] In other embodiments, when the inner boss 232 continues to move towards the third shaft assembly 03 after abutting against the stop 228, the stop 228 provides significant resistance to the inner boss 232, allowing the middle boss 227 to move into the space surrounded by the outer retaining spring 213, thereby engaging with the outer retaining spring 213 and fixing the relative positions of the outer sleeve unit 21 and the middle sleeve unit 22. The mounting hole 2213 can be installed in the middle torsion part 2211, and the inner boss 232 can be located on the side of the inner torsion part 2311 near the middle limiting groove 226. When the middle torsion part 2211 engages with the inner torsion part 2311, it is convenient to install the inner boss 232 through the mounting hole 2213. The torque is transmitted between the outer sleeve module 211, the middle sleeve module 221, and the inner sleeve module 231 through the middle torsion part 2211 along both sides of the middle sidewall 2212 in the circumferential direction. Therefore, this arrangement can ensure the strength of the middle sleeve module 221.

[0054] In some embodiments, the mounting hole 2213 and the weight-reducing hole 2214 on the adjacent torsional portion 2211 can be spaced apart along the axial direction of the middle sidewall 2212. This avoids the mounting hole 2213 and the weight-reducing hole 2214 from being concentrated in the same area, resulting in low strength. The spaced arrangement can improve the strength of the middle sleeve module 221.

[0055] In other embodiments, the dimension of the mounting hole 2213 along the axial direction of the middle sidewall 2212 can be larger than the dimension of the middle weight reduction hole 2214 along the axial direction of the middle sidewall 2212, thereby increasing the operating space and improving installation efficiency when installing the inner boss 232.

[0056] In some embodiments, as shown in FIG11, the inner sleeve module 231 may further include an inner weight-reducing hole 2313. The inner weight-reducing hole 2313 may penetrate radially through the inner torsion portion 2311 away from the inner sidewall 2312. The inner torsion portion 2311 bears less torque than the inner sidewall 2312, thereby reducing the weight of the inner sleeve module 231 while ensuring strength.

[0057] In some embodiments, the dimension D of the inner weight-reducing hole 2313 along the circumferential direction of the inner sidewall 2312 can be greater than 0 and less than or equal to 0.7 times the dimension E of the inner torsion portion 2311 along the circumferential direction of the inner sidewall 2312 near the outer limiting groove 212. Since the inner sleeve module 231 is closer to the central axis of the second shaft assembly 02 than the middle sleeve module 221, it can withstand a greater torque. In this way, the weight of the inner sleeve module 231 can be reduced as much as possible while ensuring the strength of the inner sleeve module 231.

[0058] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the spirit and scope of this disclosure.

Claims

1. A steering drive shaft, characterized in that, The steering drive shaft includes: First axis assembly; The second shaft assembly includes an outer sleeve unit, a middle sleeve unit, and an inner sleeve unit. The outer sleeve unit includes an outer sleeve module, an outer limiting groove, and an outer retaining spring. The outer sleeve module is a tubular body. The outer sleeve module is detachably connected to the first shaft assembly. The outer limiting groove extends from the inner peripheral wall of the outer sleeve module toward the outer peripheral wall of the outer sleeve module. The outer retaining spring is detachably connected to the inner peripheral wall of the outer sleeve module on the side away from the first shaft assembly. The middle sleeve unit includes a middle sleeve module, a middle boss, a middle retaining spring, and a middle limiting groove; the outer sleeve module is sleeved on the outer periphery of the middle sleeve module; the middle sleeve module includes a middle torsion part and a middle sidewall; the middle torsion part and the middle sidewall surround to form a tubular body; one end of the middle torsion part is fixedly connected to the middle sidewall, and the other end extends toward the outer limiting groove; the middle torsion part is disposed in the outer limiting groove; the middle boss is detachably connected to the outer periphery of the middle sleeve module near the outer limiting groove; the middle boss is disposed on the side of the middle sleeve module near the first shaft assembly; the middle retaining spring and the middle sleeve module... The inner peripheral wall of the block is detachably connected; the central retaining spring is disposed on the central sleeve module near the first shaft assembly; the central limiting groove extends from the inner peripheral wall of the central side wall toward the central torsion portion; the inner sleeve unit includes an inner sleeve module and an inner boss; the central sleeve module is sleeved on the outer peripheral side of the inner sleeve module; the inner sleeve module includes an inner torsion portion and an inner side wall; one end of the inner torsion portion is fixedly connected to the inner side wall, and the other end extends toward the central sleeve module; the inner torsion portion is disposed in the central limiting groove; the inner boss is detachably connected to the outer peripheral wall of the inner sleeve module near the first shaft assembly; The third axis assembly is detachably connected to the end of the inner sleeve module away from the first axis assembly. The steering drive shaft includes an extended state; the extended state includes the middle boss moving axially along the outer casing module to abut against the end of the outer retaining spring near the first shaft assembly, the resistance of the middle retaining spring to the inner boss being greater than the frictional force between the middle sidewall and the outer casing module, and the inner boss being disposed within the space surrounded by the middle retaining spring.

2. A steering drive shaft according to claim 1, characterized in that, The outer casing module includes an outer torsion portion and an outer side wall; the outer torsion portion and the outer side wall surround each other to form a tubular body; one end of the outer torsion portion is fixedly connected to the outer side wall, and the other end extends away from the outer side wall; the outer limiting groove extends from the inner circumferential wall of the outer side wall toward the outer torsion portion; the outer limiting groove is adapted to the outer torsion portion; the symmetry plane of the outer limiting groove along the circumference of the outer side wall coincides with the symmetry plane of the outer torsion portion along the circumference of the outer side wall; the radial dimension of the outer limiting groove along the outer side wall is larger than the radial dimension of the outer side wall.

3. A steering drive shaft according to claim 1, characterized in that, The middle sleeve module also includes a middle weight reduction hole; the middle weight reduction hole penetrates radially through the middle torsion part on the side away from the middle sidewall along the middle sidewall.

4. A steering drive shaft according to claim 3, characterized in that, 0 < A ≤ 0.8B; where A is the circumferential dimension of the weight-reducing hole along the middle sidewall, and B is the circumferential dimension of the torsion part near the outer limiting groove along the middle sidewall.

5. A steering drive shaft according to claim 3, characterized in that, Multiple central torsion portions are arranged circumferentially along the central sidewall; the outer limiting groove is arranged correspondingly to the central torsion portions.

6. A steering drive shaft according to claim 5, characterized in that, The weight-reducing holes on two adjacent torsional sections are spaced apart along the axial direction of the middle sidewall.

7. A steering drive shaft according to claim 5, characterized in that, The middle sleeve unit also includes a stop block; the stop block is detachably connected to the inner peripheral wall of the middle sleeve module; the stop block is disposed on the middle sleeve module on the side away from the first shaft assembly; The middle sleeve module also includes a mounting hole; the mounting hole penetrates the middle sleeve module radially along the middle sidewall; the movement trajectory of part of the inner boss is within the area projected by the mounting hole toward the inner sleeve module.

8. A steering drive shaft according to claim 7, characterized in that, The mounting hole and the weight reduction hole on the adjacent middle torsion section are spaced apart along the axial direction of the middle sidewall.

9. A steering drive shaft according to claim 1, characterized in that, The inner sleeve module also includes an inner weight reduction hole; the inner weight reduction hole penetrates radially through the inner sidewall and extends away from the inner torsion portion on the side away from the inner sidewall.

10. A steering drive shaft according to claim 9, characterized in that, 0 < D ≤ 0.7E; where D is the circumferential dimension of the inner weight-reducing hole along the inner sidewall, and E is the circumferential dimension of the inner torsion part along the inner sidewall near the outer limiting groove.

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