A steering transmission shaft

Abstract

The present invention relates to the field of vehicle technology, and in particular, to a steering transmission shaft. The device comprises: a first shaft assembly, a second shaft assembly, and a third shaft assembly. The second shaft assembly comprises an outer sleeve unit, a middle sleeve unit, and an inner sleeve unit. The outer sleeve unit comprises an outer sleeve module, an outer limit groove, and an outer retaining spring. The middle sleeve unit comprises a middle sleeve module, a middle boss, a middle retaining spring, and a middle limit groove. The outer sleeve module is sleeved on the outer peripheral side of the middle sleeve module. The middle sleeve module comprises a middle torsion portion and a middle side wall. The inner sleeve unit comprises an inner sleeve module and an inner boss. The middle sleeve module is sleeved on the outer peripheral side of the inner sleeve module. The steering transmission shaft comprises an extended state. The extended state comprises that the middle boss moves along the axial direction of the outer sleeve module to abut against one end of the outer retaining spring close to the first shaft assembly, the resistance of the middle retaining spring to the inner boss is greater than the friction between the middle side wall and the outer sleeve module, and the inner boss is arranged in the space surrounded by the middle retaining spring. In this way, the problem of how to improve the service life of the steering transmission shaft is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicles, and in particular to a steering transmission shaft. Background Art

[0002] The main function of the steering transmission shaft is to transmit the force and movement output by the steering gear to the universal joint, thereby realizing the steering movement of the wheel. At the same time, it can transmit a certain torque to ensure that the vehicle can drive smoothly and accurately according to the driver's intention during the steering process. The steering transmission shaft can usually be composed of two universal joints, an outer spline sleeve, an intermediate spline sleeve, and an inner spline sleeve. The outer spline sleeve can be sleeved on the outer circumference of the intermediate spline sleeve, and the intermediate spline sleeve can be sleeved on the outer circumference of the inner spline sleeve. One universal joint is connected to one end of the outer spline sleeve, and the other universal joint is connected to one end of the inner spline sleeve.

[0003] One end of the steering shaft is connected to the steering wheel, and the other end is connected to the steering gear. During the use of the vehicle, the steering shaft needs to be extended or shortened. For example, the vehicle's wheels will extend or shorten as the road surface rises and falls, and adjusting the height of the steering wheel will extend or shorten the steering shaft. For example, when used in heavy trucks and other vehicles, the cab must be turned over during maintenance. The turning of the cab will increase the distance between the steering wheel and the steering gear, and the steering shaft will extend or shorten accordingly. The inner spline sleeve may move relative to the outer spline sleeve and the middle spline sleeve. Due to the small diameter of the inner spline sleeve, it is more easily damaged when subjected to a certain force than the outer spline sleeve with a larger diameter, which will reduce the service life and the strength of the spline sleeve, affecting the bearing capacity of the steering shaft, thereby reducing the steering stability and driving safety of the vehicle. Summary of the invention

[0004] In order to solve the problem of how to improve the service life of a steering transmission shaft, the present invention provides a steering transmission shaft, comprising:

[0005] A first shaft assembly;

[0006] A second shaft assembly, the second shaft assembly comprises an outer sleeve unit, a middle sleeve unit, and an inner sleeve unit; the outer sleeve unit comprises 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 circumferential wall of the outer sleeve module toward the outer circumferential wall of the outer sleeve module; the outer retaining spring is detachably connected to the inner circumferential wall of the outer sleeve module 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 peripheral side of the middle sleeve module; the middle sleeve module includes a middle torsion portion and a middle side wall; the middle torsion portion and the middle side wall surround to form a tubular body; one end of the middle torsion portion is fixedly connected to the middle side wall, and the other end extends toward the outer limiting groove; the middle torsion portion is arranged in the outer limiting groove; the middle boss is detachably connected to the outer peripheral wall of the middle sleeve module near the outer limiting groove; the middle boss is arranged on the side of the middle sleeve module near the first shaft assembly; the middle retaining spring is connected to the middle sleeve module The inner circumferential wall of the block is detachably connected; the middle retaining spring is arranged on the middle sleeve module on the side close to the first shaft assembly; the middle limiting groove extends from the inner circumferential wall of the middle side wall toward the middle torsion portion; the inner sleeve unit includes an inner sleeve module and an inner boss; the middle sleeve module is sleeved on the outer circumference 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 direction close to the middle sleeve module; the inner torsion portion is arranged in the middle limiting groove; the inner boss is detachably connected to the outer circumferential wall of the inner sleeve module on the side close to the first shaft assembly;

[0008] A third shaft assembly; the third shaft assembly is detachably connected to an end of the inner sleeve module away from the first shaft assembly;

[0009] The steering transmission shaft includes an extended state; the extended state includes the middle boss moving along the axial direction of the outer sleeve module to abut against an end of the outer retaining spring close to the first shaft assembly, the resistance of the middle retaining spring on the inner boss is greater than the friction between the middle side wall and the outer sleeve module, and the inner boss is arranged in the space surrounded by the middle retaining spring.

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

[0011] In some embodiments, the middle module further includes a middle weight-reducing hole; the middle weight-reducing hole penetrates the middle torsion portion on a side away from the middle side wall in a radial direction of the middle side wall.

[0012] In some embodiments, 0<A≤0.8B; wherein A is the size of the middle weight-reducing hole along the circumference of the middle side wall, and B is the size of the middle torsion portion along the circumference of the middle side wall close to the outer limiting groove.

[0013] In some embodiments, a plurality of the middle torsion portions are arranged at intervals along the circumference of the middle side wall; and the outer limiting grooves are arranged corresponding to the middle torsion portions.

[0014] In some embodiments, the middle weight-reducing holes on two adjacent middle torsion portions are spaced apart along the axial direction of the middle side wall.

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

[0016] The middle sleeve module also includes a mounting hole; the mounting hole penetrates the middle sleeve module in the radial direction of the middle side wall; the movement track of part of the inner boss is within the area where the mounting hole is projected toward the inner sleeve module.

[0017] In some embodiments, the mounting hole and the middle weight-reducing hole on the adjacent middle torsion portion are spaced apart from each other along the axial direction of the middle side wall.

[0018] In some embodiments, the inner sleeve module further includes an inner weight-reducing hole; the inner weight-reducing hole penetrates the inner torsion portion along the radial direction of the inner side wall and is away from the inner side wall.

[0019] In some embodiments, 0<D≤0.7E; wherein D is the size of the inner weight-reducing hole along the circumference of the inner wall, and E is the size of the inner torsion portion along the circumference of the inner wall close to the outer limiting groove.

[0020] In order to solve the problem of how to improve the service life of the steering transmission shaft, the present invention has the following advantages:

[0021] The steering transmission 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 limit groove, and an outer retaining spring. The middle sleeve unit may include a middle sleeve module, a middle boss, a middle retaining spring, and a middle limit groove. The middle sleeve module may include a middle torsion portion and a middle side wall. The middle boss may be arranged on a side of the middle sleeve module close to the first shaft assembly, so that when the outer sleeve module moves toward the first shaft assembly relative to the middle sleeve module, the middle boss may be moved into the space surrounded by the outer retaining spring, thereby realizing engagement with the outer retaining spring, fixing the relative position of the middle sleeve unit and the outer sleeve unit, and the middle boss may move toward the outer retaining spring on the side away from the first shaft assembly, so that the distance between the first shaft assembly and the third shaft assembly becomes larger. 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 side wall. The inner boss may be used to cooperate with the middle retaining spring to control the relative movement of the middle sleeve unit and the inner sleeve unit. The steering transmission shaft may include an extended state. The extended state may include the middle boss moving from being spaced apart from the outer retaining spring along the axial direction of the outer jacket module to abutting against one end of the outer retaining spring close to the first shaft assembly, the resistance of the middle retaining spring to the inner boss is greater than the friction between the middle side wall and the outer jacket module, and the inner boss is in the space surrounded by the middle retaining spring. In this way, when the spacing between the first shaft assembly and the third shaft assembly increases during the use of the vehicle, the inner sleeve unit and the middle sleeve unit can be relatively fixed, and the outer jacket unit moves relative to the inner sleeve unit and the middle sleeve unit respectively. Since the outer jacket unit has a larger diameter and can withstand a larger force, the steering transmission shaft is not easily damaged, and the strength of the steering transmission shaft after being stretched can be improved, thereby solving the problem of how to improve the life of the steering transmission shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of a steering transmission shaft according to an embodiment is shown;

[0023] Figure 2 A schematic diagram of a second shaft assembly according to an embodiment is shown;

[0024] Figure 3 A schematic diagram of a second shaft assembly of another embodiment is shown;

[0025] Figure 4 A schematic diagram of a steering transmission shaft in another embodiment is shown;

[0026] Figure 5 A partial schematic diagram of a jacket unit of an embodiment is shown;

[0027] Figure 6 A schematic diagram of a jacket unit according to an embodiment is shown;

[0028] Figure 7 A partial schematic diagram of a middle set unit of an embodiment is shown;

[0029] Figure 8 A partial schematic diagram of a middle set unit of another embodiment is shown;

[0030] Fig. 9 A partial schematic diagram of a middle set unit of another embodiment is shown;

[0031] Fig.10 A partial schematic diagram of an inner sleeve unit of an embodiment is shown;

[0032] Fig.11 A schematic diagram of an inner sleeve unit according to an embodiment is shown;

[0033] Fig.12 A schematic diagram of an inner sleeve unit of another embodiment is shown.

[0034] Figure markings: 01 first shaft assembly; 02 second shaft assembly; 21 outer sleeve unit; 211 outer sleeve module; 2111 outer torsion portion; 2112 outer side wall; 212 outer limiting groove; 213 outer retaining spring; 22 middle sleeve unit; 221 middle sleeve module; 2211 middle torsion portion; 2212 middle side wall; 2213 mounting hole; 2214 middle weight reduction hole; 226 middle limiting groove; 227 middle boss; 228 block; 229 middle retaining spring; 23 inner sleeve unit; 231 inner sleeve module; 2311 inner torsion portion; 2312 inner side wall; 2313 inner weight reduction hole; 2314 inner weight reduction groove; 232 inner boss; 03 third shaft assembly. DETAILED DESCRIPTION

[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, rather than implying any limitation on the scope of the present disclosure.

[0036] As used herein, the term "including" and its variants are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "based at least in part 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 orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like is based on the orientation or position relationship shown in the accompanying drawings. These terms are mainly for better describing the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to being used to indicate an orientation or position relationship, some of the above terms may also be used to indicate other meanings, such as the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances. In addition, the terms "install", "set", "provided with", "connected" and "connected" should be understood in a broad sense. 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 directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, 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 and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0037] The steering shaft will lengthen or shorten when the wheels of the vehicle go up and down with the road surface, when the steering wheel height is adjusted, or when the cab of a heavy truck is being repaired. This may cause the inner spline sleeve to move relative to the outer spline sleeve and the middle spline sleeve. Since the inner spline sleeve has a small diameter, it is more easily damaged when subjected to a certain force than the outer spline sleeve with a larger diameter, thereby reducing its service life and the strength of the spline sleeve. This affects the bearing capacity of the steering shaft, thereby reducing the steering stability and driving safety of the vehicle. In order to solve the problem of how to increase the life of the steering shaft, this embodiment provides a steering shaft, such as Figure 1 As shown, the steering transmission shaft may include a first shaft assembly 01 , a second shaft assembly 02 , and a third shaft assembly 03 .

[0038] like Figure 4As shown, the second shaft assembly 02 may include an outer sleeve unit 21, a middle sleeve unit 22, and an inner sleeve unit 23. Figure 6 As shown, the jacket unit 21 may include a jacket module 211, an outer limiting groove 212, and an outer retaining spring 213. Figure 5 As shown, the outer sleeve module 211 can be a tubular body, so that the outer sleeve module 211 is hollow in this way, and there can be enough space to install the middle sleeve unit 22 and the inner sleeve unit 23. The outer sleeve module 211 can be detachably connected with the first shaft assembly 01, which is convenient for the disassembly and installation of the outer sleeve module 211. The outer limit groove 212 can extend from the inner peripheral wall of the outer sleeve module 211 toward the outer peripheral wall of the outer sleeve module 211, and the outer limit groove 212 can be used to cooperate with the middle sleeve unit 22, so as to transmit torque. The outer retaining spring 213 can be detachably connected to the inner peripheral wall of the outer sleeve module 211 away from one side of the first shaft assembly 01, which is convenient for the disassembly and connection of the outer retaining spring 213, and the outer retaining spring 213 can be replaced separately when maintenance is needed. The outer retaining spring 213 can be used to cooperate with the middle sleeve unit 22, so as 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 limit groove 226. The outer sleeve module 211 may be sleeved on the outer peripheral side of the middle sleeve module 221, so that the outer sleeve module 211 can move relative to the middle sleeve module 221. The middle sleeve module 221 may include a middle torsion portion 2211 and a middle side wall 2212. The middle torsion portion 2211 may be surrounded with the middle side wall 2212 to form a tubular body, so that the middle sleeve module 221 may be hollow so that there is enough space to install the inner sleeve unit 23. One end of the middle torsion portion 2211 may be fixedly connected to the middle side wall 2212, so as to improve the structural strength of the middle sleeve module 221 and prevent deformation or damage. The other end of the middle torsion portion 2211 may extend toward the outer limit groove 212, and the middle torsion portion 2211 may be arranged in the outer limit groove 212. The first shaft assembly 01 drives the outer side wall 2112 and the outer limit groove 212 to rotate, and the middle torsion portion 2211 disposed in the outer limit groove 212 can rotate along 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 close to the outer limit groove 212 can be detachably connected, which is convenient for the removal and installation of the middle boss 227. When maintenance is required, the middle boss 227 can be replaced separately. The middle boss 227 can be arranged on the side of the middle sleeve module 221 close to the first shaft assembly 01, so that when the outer sleeve module 211 moves relative to the middle sleeve module 221 toward the first shaft assembly 01, the middle boss 227 can be moved into the space surrounded by the outer retaining spring 213, thereby achieving engagement with the outer retaining spring 213 to fix the relative position of the middle sleeve unit 22 and the outer sleeve unit 21. The middle boss 227 can move in the direction of the outer retaining spring 213 away from the side of the first shaft assembly 01, so that the distance between the first shaft assembly 01 and the third shaft assembly 03 becomes larger. The middle retaining spring 229 can be detachably connected to the inner circumferential wall of the middle sleeve module 221 to facilitate the removal and installation of the middle retaining spring 229. The middle retaining spring 229 can be arranged on the side of the middle sleeve module 221 close to the first shaft assembly 01, and the middle limit groove 226 can extend from the inner circumferential wall of the middle side wall 2212 toward the middle torsion portion 2211. The middle limit groove 226 can be used to cooperate with the inner sleeve unit 23 to transmit torque. Fig.10As shown, 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 peripheral side of the inner sleeve module 231, so that the middle sleeve module 221 can move relative to the inner sleeve module 231. The inner sleeve module 231 may include an inner twisting portion 2311 and an inner side wall 2312. One end of the inner torsion portion 2311 can be fixedly connected to the inner wall 2312, and the other end can extend toward the direction close to the middle set module 221. The inner torsion portion 2311 can be set in the middle limit groove 226, and the middle limit groove 226 can be used for guiding. The first shaft assembly 01 drives the outer wall 2112 and the outer limit groove 212 to rotate. The middle torsion portion 2211 set in the outer limit groove 212 can rotate with the outer wall 2112, thereby driving the middle limit groove 226 and the middle side wall 2212 to rotate. The inner torsion portion 2311 set in the middle limit groove 226 can rotate with the middle side wall 2212, thereby driving the inner wall 2312 to rotate. The inner boss 232 can be detachably connected to the outer wall of the inner sleeve module 231 close to the first shaft assembly 01, so that the inner boss 232 can be freely removed 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 one end away from the first shaft assembly 01, which is convenient for the removal and installation of the third shaft assembly 03. The outer retaining spring 213 can have an opening at one end close to the first shaft assembly 01, which is convenient for the middle boss 227 to enter or leave the space surrounded by the outer retaining spring 213 from the opening of the outer retaining spring 213. The middle retaining spring 229 can have an opening at one end away from the first shaft assembly 01, which is convenient for the inner boss 232 to enter or leave the space surrounded by the middle retaining spring 229 from the opening of the middle retaining spring 229.

[0041] The steering transmission shaft may include an extended state. The extended state may include the middle boss 227 moving from being spaced apart from the outer retaining spring 213 along the axial direction of the outer jacket module 211 to abutting against one end of the outer retaining spring 213 close to the first shaft assembly 01, the resistance of the middle retaining spring 229 to the inner boss 232 is greater than the friction between the middle side wall 2212 and the outer jacket module 211, and the inner boss 232 is arranged in the space surrounded by the middle retaining spring 229. In this way, when the spacing between the first shaft assembly 01 and the third shaft assembly 03 increases during the use of the vehicle, the inner sleeve unit 23 and the middle sleeve unit 22 can be relatively fixed, and the outer jacket unit 21 moves relatively with the inner sleeve unit 23 and the middle sleeve unit 22 respectively. Since the outer jacket unit 21 has a larger diameter and can withstand a larger force, the steering transmission shaft is not easily damaged, and the strength of the steering transmission shaft after being stretched can be improved, thereby improving the life of the steering transmission shaft.

[0042] In other embodiments, the middle limit groove 226 can be matched with the middle torsion portion 2211, the symmetric plane of the middle limit groove 226 along the circumference of the middle side wall 2212 can coincide with the symmetric plane of the middle torsion portion 2211 along the circumference of the middle side wall 2212, and the radial dimension of the middle limit groove 226 along the middle side wall 2212 can be greater than the radial dimension of the middle side wall 2212 along the middle side wall 2212, so that the weight of the steering transmission shaft can be reduced. The inner torsion portion 2311 can be surrounded by the inner side wall 2312 to form a tubular body, so that the inner sleeve module 231 is hollow to achieve weight reduction and improve vehicle performance. Multiple inner torsion parts 2311 can be evenly spaced along the circumference of the inner side wall 2312, and the middle limit grooves 226 can be arranged corresponding to the number and position of the inner torsion parts 2311. In this way, the strength of the steering transmission shaft can be strengthened, and the mass distribution of the steering transmission shaft can be as balanced as possible when the steering transmission shaft rotates, so as to avoid vibration and noise caused by uneven mass distribution. Letting multiple groups of middle limit grooves 226 cooperate with the inner torsion parts 2311 helps to disperse the force. Fig.12 As shown, the inner sleeve module 231 may further include an inner weight reduction groove 2314, which may extend from the inner circumferential wall of the inner side wall 2312 toward the inner torsion portion 2311, thereby reducing the weight of the inner sleeve module 231. Figure 3 As shown, the outer retaining spring 213 can be arranged on the inner peripheral wall of the outer torsion portion 2111 away from the middle sleeve module 221. The outer retaining spring 213 is away from the central axis of the inner sleeve module 231, and the torque is small, which can enhance the strength of the outer sleeve unit 21. Fig. 9 As shown, the middle boss 227 can be arranged on the side of the middle torsion portion 2211 away from the inner sleeve module 231. The middle boss 227 is away from the central axis of the inner sleeve module 231, bears less torque, and can enhance the strength of the middle sleeve unit 22.

[0043] In some embodiments, the outer jacket module 211 may include an outer twisting portion 2111 and an outer sidewall 2112. The outer twisting portion 2111 may be surrounded with the outer sidewall 2112 to form a tubular body, so that the outer jacket module 211 is hollow and can achieve weight reduction and has enough space to install the middle jacket unit 22 and the inner jacket unit 23. One end of the outer twisting portion 2111 may be fixedly connected to the outer sidewall 2112, and the other end of the outer twisting portion 2111 may extend away from the outer sidewall 2112, and the outer limit groove 212 may extend from the inner peripheral wall of the outer sidewall 2112 toward the outer twisting portion 2111, so that the outer limit groove 212 can be used to cooperate with the middle jacket unit 22. The outer limit groove 212 can be adapted to the outer twisting portion 2111, so as to transmit torque. The outer limit groove 212 can overlap with the outer twisting portion 2111 along the symmetric plane of the outer sidewall 2112 circumferential direction and the symmetric plane of the outer twisting portion 2111 along the outer sidewall 2112 circumferential direction. The radial dimension of the outer limit groove 212 along the outer wall 2112 can be larger than the radial dimension of the outer wall 2112 along the outer wall 2112. In this way, the outer jacket module 211 can have sufficient structural strength and the wall thickness of part of the outer jacket module 211 can be reduced to achieve weight reduction.

[0044] In some other embodiments, the outer jacket module 211 may further include an outer weight-reducing hole, which may penetrate the outer torsion portion 2111 away from the outer jacket wall 2112 in the radial direction of the outer jacket wall 2112, thereby reducing the weight of the outer jacket module 211.

[0045] In some embodiments, Figure 8 As shown, the middle sleeve module 221 may further include a middle weight reduction hole 2214. The middle weight reduction hole 2214 may penetrate the side of the middle torsion portion 2211 away from the middle side wall 2212 along the radial direction of the middle side wall 2212. Since the side of the middle torsion portion 2211 away from the middle side wall 2212 is far from the central axis of the inner sleeve module 231, and the torque transmitted between the outer sleeve module 211, the middle sleeve module 221 and the inner sleeve module 231 is transmitted through the two sides of the middle torsion portion 2211 along the circumferential direction of the middle side wall 2212, 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 middle weight-reducing hole 2214 along the circumference of the middle side wall 2212 can be greater than 0 and less than or equal to 0.8 times the dimension B of the middle torsion portion 2211 along the circumference of the middle side wall 2212 close to the outer limit groove 212. Within this range, the weight of the middle sleeve module 221 can be reduced to improve the working efficiency of the vehicle while ensuring the strength of the middle sleeve module 221, avoiding the influence of excessive size on the strength of the middle sleeve module 221, and avoiding the influence of excessive size on the weight-reducing effect of the middle sleeve module 221.

[0047] In other embodiments, the axial dimension C of the middle weight reduction hole 2214 along the middle side wall 2212 may be 4 to 5 times the circumferential dimension A of the middle weight reduction hole 2214 along the middle side wall 2212. Within this range, the weight of the middle sleeve module 221 can be further effectively reduced while ensuring the strength of the middle sleeve module 221.

[0048] In some embodiments, multiple middle torsion parts 2211 can be arranged at intervals along the circumference of the middle side wall 2212, and the outer limit grooves 212 can be arranged corresponding to the middle torsion parts 2211, and the outer limit grooves 212 can cooperate with the middle torsion parts 2211 to transmit torque. In this way, multiple groups of middle torsion parts 2211 and outer limit grooves 212 cooperate with each other to disperse the force, and the strength of the middle sleeve module 221 can be strengthened, thereby strengthening the strength of the steering transmission shaft.

[0049] In other embodiments, a plurality of middle torsion portions 2211 may be evenly spaced along the circumference of the middle side wall 2212, and the outer limit grooves 212 may be arranged corresponding to the number and positions of the middle torsion portions 2211, so that when the steering drive shaft rotates, the mass distribution of the steering drive shaft can be as balanced as possible to avoid vibration and noise caused by uneven mass distribution.

[0050] In some embodiments, the middle weight-reducing holes 2214 on two adjacent middle torsion portions 2211 can be arranged at axial intervals along the middle side wall 2212 to avoid excessive weakening of the material in a local area of ​​the middle torsion portion 2211, thereby improving the overall structural strength of the middle sleeve module 221, and also improving the heat dissipation performance of the middle sleeve module 221 and the service life of the middle sleeve module 221.

[0051] In some embodiments, Figure 7 As shown, the middle sleeve unit 22 may further include a stopper 228, and the stopper 228 may be detachably connected to the inner peripheral wall of the middle sleeve module 221, so as to facilitate the installation and removal of the stopper 228. The stopper 228 may be arranged on the side of the middle sleeve module 221 away from the first shaft assembly 01. The stopper 228 may be used for limiting, so as to prevent the second shaft assembly 02 from exceeding the range of motion, and to protect the second shaft assembly 02 from damage. When the inner boss 232 abuts against the stopper 228, the resistance of the stopper 228 to the inner boss 232 may cause the middle boss 227 to move into the space surrounded by the outer retaining spring 213, so as to achieve engagement with the outer retaining spring 213, and fix the relative position of the outer sleeve unit 21 and the middle sleeve unit 22.

[0052] like Figure 2As shown, the middle sleeve module 221 may also include a mounting hole 2213. The mounting hole 2213 may penetrate the middle sleeve module 221 along the radial direction of the middle side wall 2212, and the movement trajectory of part of the inner boss 232 is within the area projected by the mounting hole 2213 toward the inner sleeve module 231. Since the middle sleeve module 221 is provided with a middle retaining spring 229 on the side close to the first shaft assembly 01, and the middle sleeve module 221 is provided with a stopper 228 on the side away from the first shaft assembly 01, when the inner sleeve module 231 provided with the inner boss 232 is inserted into the middle sleeve module 221 axially along the middle sleeve module 221, it will be blocked and cannot be assembled. Therefore, the mounting hole 2213 is provided, so that the inner sleeve module 231 can be inserted into the middle sleeve module 221 axially along the middle sleeve module 221, and then the inner boss 232 is connected to the outer peripheral wall of the inner sleeve module 231 through the mounting hole 2213, so that the inner sleeve module 231 can be smoothly installed to the middle sleeve module 221.

[0053] In other embodiments, when the inner boss 232 continues to move toward the third shaft assembly 03 after contacting the stopper 228, the resistance of the stopper 228 to the inner boss 232 is large, so that the middle boss 227 can be moved into the space surrounded by the outer retaining spring 213, thereby engaging with the outer retaining spring 213 to fix the relative position of the outer sleeve unit 21 and the middle sleeve unit 22. The mounting hole 2213 can be mounted on the middle torsion portion 2211, and the inner boss 232 can be arranged on the side of the inner torsion portion 2311 close to the middle limiting groove 226. When the middle torsion portion 2211 cooperates with the inner torsion portion 2311, it is convenient to install the inner boss 232 from the mounting hole 2213. The torque transmitted between the outer sleeve module 211, the middle sleeve module 221 and the inner sleeve module 231 is transmitted through the middle torsion portion 2211 along the circumferential sides of the middle side wall 2212, so this arrangement can ensure the strength of the middle sleeve module 221.

[0054] In some embodiments, the mounting hole 2213 and the middle weight reduction hole 2214 on the adjacent middle torsion portion 2211 can be arranged at axial intervals along the middle side wall 2212, so as to avoid the mounting holes 2213 and the middle weight reduction holes 2214 being concentrated in the same area to cause low strength. The interval arrangement can improve the strength of the middle sleeve module 221.

[0055] In other embodiments, the axial dimension of the mounting hole 2213 along the middle side wall 2212 may be larger than the axial dimension of the middle lightening hole 2214 along the middle side wall 2212 , so that the operating space is large when installing the inner boss 232 and the installation efficiency is improved.

[0056] In some embodiments, Fig.11As shown, the inner sleeve module 231 may further include an inner weight-reducing hole 2313. The inner weight-reducing hole 2313 may penetrate the inner torsion portion 2311 away from the inner sidewall 2312 along the radial direction of the inner sidewall 2312, and 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 circumference of the inner sidewall 2312 may be greater than 0 and less than or equal to 0.7 times the dimension E of the inner torsion portion 2311 along the circumference 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 bears a greater torque, so that 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 appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present disclosure.

Claims

1. A steering transmission shaft, characterized in that: The steering transmission shaft comprises: A first shaft assembly; A second shaft assembly, the second shaft assembly comprises an outer sleeve unit, a middle sleeve unit, and an inner sleeve unit; the outer sleeve unit comprises 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 circumferential wall of the outer sleeve module toward the outer circumferential wall of the outer sleeve module; the outer retaining spring is detachably connected to the inner circumferential wall of the outer sleeve module 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 peripheral side of the middle sleeve module; the middle sleeve module includes a middle torsion portion and a middle side wall; the middle torsion portion and the middle side wall surround to form a tubular body; one end of the middle torsion portion is fixedly connected to the middle side wall, and the other end extends toward the outer limiting groove; the middle torsion portion is arranged in the outer limiting groove; the middle boss is detachably connected to the outer peripheral wall of the middle sleeve module near the outer limiting groove; the middle boss is arranged on the side of the middle sleeve module near the first shaft assembly; the middle retaining spring is connected to the middle sleeve module The inner circumferential wall of the block is detachably connected; the middle retaining spring is arranged on the middle sleeve module on the side close to the first shaft assembly; the middle limiting groove extends from the inner circumferential wall of the middle side wall toward the middle torsion portion; the inner sleeve unit includes an inner sleeve module and an inner boss; the middle sleeve module is sleeved on the outer circumference 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 direction close to the middle sleeve module; the inner torsion portion is arranged in the middle limiting groove; the inner boss is detachably connected to the outer circumferential wall of the inner sleeve module on the side close to the first shaft assembly; A third shaft assembly; the third shaft assembly is detachably connected to an end of the inner sleeve module away from the first shaft assembly; The steering transmission shaft includes an extended state; the extended state includes the middle boss moving along the axial direction of the outer sleeve module to abut against an end of the outer retaining spring close to the first shaft assembly, the resistance of the middle retaining spring on the inner boss is greater than the friction between the middle side wall and the outer sleeve module, and the inner boss is arranged in the space surrounded by the middle retaining spring.

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

3. A steering transmission shaft according to claim 1, characterized in that: The middle sleeve module further comprises a middle weight-reducing hole; the middle weight-reducing hole penetrates the middle torsion portion on a side away from the middle side wall in a radial direction of the middle side wall.

4. A steering transmission shaft according to claim 3, characterized in that: 0<A≤0.8B; wherein A is the size of the middle weight-reducing hole along the circumferential direction of the middle side wall, and B is the size of the middle torsion portion close to the outer limiting groove along the circumferential direction of the middle side wall.

5. The steering transmission shaft according to claim 3, characterized in that: A plurality of the middle torsion portions are arranged at intervals along the circumferential direction of the middle side wall; and the outer limiting grooves are arranged corresponding to the middle torsion portions.

6. A steering transmission shaft according to claim 5, characterized in that: The middle weight-reducing holes on two adjacent middle torsion portions are arranged at intervals along the axial direction of the middle side wall.

7. The steering transmission shaft according to claim 5, characterized in that: The middle sleeve unit further comprises a stopper; the stopper is detachably connected to the inner peripheral wall of the middle sleeve module; the stopper is arranged on a side of the middle sleeve module away from the first shaft assembly; The middle sleeve module also includes a mounting hole; the mounting hole penetrates the middle sleeve module in the radial direction of the middle side wall; the movement track of part of the inner boss is within the area where the mounting hole is projected toward the inner sleeve module.

8. The steering transmission shaft according to claim 7, characterized in that: The mounting hole and the middle weight-reducing hole on the adjacent middle torsion portion are arranged axially spaced apart from each other along the middle side wall.

9. The steering transmission shaft according to claim 1, characterized in that: The inner sleeve module further comprises an inner weight-reducing hole; the inner weight-reducing hole penetrates the inner torsion portion in a radial direction of the inner side wall and is away from the inner side wall.

10. The steering transmission shaft according to claim 9, characterized in that: 0<D≤0.7E; wherein D is the size of the inner weight-reducing hole along the circumferential direction of the inner wall, and E is the size of the inner torsion portion along the circumferential direction of the inner wall close to the outer limiting groove.

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