Electric power steering gear and worm gear and worm meshing clearance adjusting mechanism thereof

Abstract

One end of an adjusting rod is rotationally connected with a first shell, the other end, namely the free end, of the adjusting rod abuts against a first bearing, and when a gap between a worm and a worm gear is too large, the adjusting rod is rotated to push the first bearing in the direction close to the worm gear, so that the worm gear and the worm gear are meshed with each other. Therefore, the worm is close to the worm gear, the gap between the worm and the worm gear is reduced, the effect of eliminating the transmission gap between the worm gear and the worm is achieved, and the force transmission performance condition is guaranteed. When the gap between the worm and the worm gear is too small, the adjusting rod is rotated reversely to push the first bearing in the direction away from the worm gear, the worm is made to be away from the worm gear, the gap between the worm and the worm gear is increased, and the gap between the worm gear and the worm can be flexibly adjusted.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicles, in particular to an electric power steering device and a worm gear meshing clearance adjusting mechanism thereof. Background Art

[0002] The reducer mechanism is the most critical component mechanism in the automobile electric power steering system. A worm wheel and a worm are arranged inside the reducer mechanism. After long-term engagement, the worm wheel and the worm will cause wear. This wear will cause a gap between the meshing tooth surfaces of the worm wheel and the worm gear, which are relatively fixed on the rotating shaft core, which may affect the force transmission performance. In addition, when the steering wheel is changed and the vehicle passes through bumpy roads, the worm wheel and the worm gear will mesh and make abnormal noises, making the driver feel uncomfortable. Utility Model Content

[0003] In response to the technical problem of clearance between the meshing tooth surfaces of the worm wheel and the worm, the utility model provides an electric power steering gear and a worm wheel meshing clearance adjustment mechanism thereof, by which the clearance between the worm and the worm wheel is reduced by pushing the first bearing toward the worm wheel through an adjusting rod, thereby eliminating the transmission clearance between the worm wheel and the worm.

[0004] To solve the above problems, the technical solution provided by the utility model is: a worm gear meshing clearance adjustment mechanism, comprising a first shell for installing the worm and a second shell for installing the worm wheel, the first shell and the second shell are connected to each other, a first bearing for being sleeved on one end of the worm is provided in the first shell, an adjustment rod is rotatably provided in the first shell, and the free end of the adjustment rod abuts against the side of the first bearing facing away from the worm wheel.

[0005] Optionally, the adjusting rod is a screw rod, and the first shell is provided with a screw hole rotatably connected to the screw rod, and the center line of the screw hole is perpendicular to the axis of the first bearing.

[0006] Optionally, a first sleeve is provided on the outer peripheral wall of the first bearing, the first housing is provided with a mounting cavity for mounting the first sleeve, and the free end of the adjusting rod passes through the first sleeve and abuts against the first bearing.

[0007] Optionally, a second bearing is further provided in the first housing, and the second bearing is used to be sleeved on the outer peripheral wall of the end where the worm is connected to the motor, and a second shaft sleeve is sleeved on the outer peripheral wall of the second bearing.

[0008] The utility model also discloses an electric power steering device, including a worm wheel, a worm, a motor and the worm wheel and worm meshing clearance adjustment mechanism mentioned above, wherein the worm wheel is located inside a first housing, the worm wheel is located inside a second housing, the worm wheel is meshed with the worm, the first bearing sleeve is arranged at one end of the worm, and the other end of the worm is connected to the motor.

[0009] Optionally, the worm is connected to the motor through a coupling. The input end of the worm and the output shaft of the motor are respectively inserted into both ends of the coupling, and an elastic pad is sleeved on the outer peripheral wall of the coupling.

[0010] Optionally, it further includes a spring. One end of the spring elastically abuts against the input end of the worm, and the other end of the spring passes through the coupling and supports on the output shaft of the motor. The worm, the coupling, the spring, and the output end of the motor are coaxially arranged.

[0011] Optionally, an end cover and a lock nut are further arranged in the first housing. The end cover cooperates with the end of the worm away from the motor, and the lock nut abuts against the lower end surface of the second bearing.

[0012] Adopting the technical solution provided by the present utility model, compared with the prior art, it has the following beneficial effects: One end of the adjusting rod is rotatably connected to the first housing, and the other end of the adjusting rod, that is, the free end, abuts against the first bearing. When the gap between the worm and the worm gear is too large, rotate the adjusting rod to push the first bearing in the direction close to the worm gear, so as to make the worm approach the worm gear, reduce the gap between the worm and the worm gear, and play a role in eliminating the transmission gap between the worm gear and the worm, thereby ensuring the force transmission performance. And when the gap between the worm and the worm gear is too small, rotate the adjusting rod in the reverse direction to push the first bearing in the direction away from the worm gear, make the worm away from the worm gear, and increase the gap between the worm and the worm gear, so as to flexibly adjust the gap between the worm gear and the worm. Description of the Drawings

[0013] Figure 1 is a schematic structural diagram of a worm gear and worm meshing clearance adjusting mechanism proposed by an embodiment of the present utility model;

[0014] Figure 2 is a cross-sectional view of an electric power steering gear proposed by an embodiment of the present utility model.

[0015] The marks in each drawing are: 1. First housing; 2. Second housing; 3. First bearing; 4. Adjusting rod; 5. First bushing; 6. Second bearing; 7. Second bushing; 8. Worm gear; 9. Worm; 10. Motor; 11. Elastic pad; 12. Spring; 13. End cover; 14. Lock nut; 15. Oil seal. Detailed Embodiments

[0016] To further understand the content of the present utility model, the present utility model will be described in detail in combination with the drawings and embodiments.

[0017] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant utility model, rather than to limit the utility model. It should also be noted that, for ease of description, only the parts related to the utility model are shown in the accompanying drawings. Multiple technical solutions in the same embodiment, and multiple technical solutions in different embodiments, can be arranged and combined to form new technical solutions that do not have contradictions or conflicts, all of which are within the scope of protection required by the present utility model.

[0018] Combined with Figure 1 The present embodiment provides a worm gear meshing clearance adjustment mechanism, comprising a first housing 1 for mounting a worm 9 and a second housing 2 for mounting a worm wheel 8, the first housing 1 and the second housing 2 are connected to each other, a first bearing 3 for sleeved on one end of the worm 9 is arranged in the first housing 1, an adjustment rod 4 is rotatably arranged in the first housing 1, and the free end of the adjustment rod 4 abuts against the side of the first bearing 3 away from the worm wheel 8. One end of the adjustment rod 4 is rotatably connected to the first housing 1, and the other end of the adjustment rod 4, i.e., the free end, abuts against the first bearing 3. When the clearance between the worm 9 and the worm wheel 8 is too large, the adjustment rod 4 is rotated to push the first bearing 3 in the direction close to the worm wheel 8, thereby making the worm 9 close to the worm wheel 8, reducing the clearance between the worm 9 and the worm wheel 8, thereby eliminating the transmission clearance between the worm wheel 8 and the worm 9, and thereby ensuring the force transmission performance. When the gap between the worm 9 and the worm wheel 8 is too small, the adjusting rod 4 is rotated in the opposite direction to push the first bearing 3 away from the worm wheel 8, so that the worm 9 is away from the worm wheel 8, and the gap between the worm 9 and the worm wheel 8 is increased, so that the gap between the worm wheel 8 and the worm 9 can be flexibly adjusted. The adjusting rod 4 is a screw rod, and the first housing 1 is provided with a screw hole rotatably connected to the screw rod, and the center line of the screw hole is perpendicular to the axis of the first bearing 3.

[0019] In this embodiment, combined with the attached Figure 1 The outer peripheral wall of the first bearing 3 is sleeved with a first sleeve 5, the first housing 1 is provided with a mounting cavity for mounting the first sleeve 5, and the free end of the adjusting rod 4 passes through the first sleeve 5 and abuts against the first bearing 3. The outer ring of the first bearing 3 contacts the first sleeve 5, the inner ring of the first bearing 3 contacts the worm 9, and the first sleeve 5 provides support for the first bearing 3 and the worm 9. The first sleeve 5 is made of a flexible material.

[0020] In this embodiment, combined with the attached Figure 1 A second bearing 6 is also provided in the first housing 1. The second bearing 6 is used to be sleeved on the outer peripheral wall of the end where the worm 9 is connected to the motor 10. The outer peripheral wall of the second bearing 6 is sleeved with a second sleeve 7. The first bearing 3 and the second bearing 6 support the worm 9 respectively.

[0021] The utility model also discloses an electric power steering device, as shown in the attached Figure 2, including a worm wheel 8, a worm 9, a motor 10, and the worm wheel 8 and worm 9 meshing clearance adjusting mechanism described above. The worm wheel 8 is located inside the first housing 1, the worm wheel 8 is located inside the second housing 2, the worm wheel 8 meshes with the worm 9, the first bearing 3 is sleeved on one end of the worm 9, and the other end of the worm 9 is connected to the motor 10.

[0022] In this embodiment, as shown in the attached Figure 2 , the worm 9 and the motor 10 are connected by a coupling. The input end of the worm 9 and the output shaft of the motor 10 are respectively inserted into both ends of the coupling. An elastic pad 11 is sleeved on the outer peripheral wall of the coupling. The input end of the worm 9 is connected to the output shaft of the motor 10 through the coupling. The coupling can eliminate the jamming caused by the non - concentricity of the axis of the output shaft of the motor 10 and the axis of the worm 9. The material of the elastic pad 11 can be rubber.

[0023] In this embodiment, as shown in the attached Figure 2 , it further includes a spring 12. One end of the spring 12 elastically abuts against the input end of the worm 9, and the other end of the spring 12 passes through the coupling and supports on the output shaft of the motor 10. The worm 9, the coupling, the spring 12, and the output end of the motor 10 are coaxially arranged. The spring provides an axial pre - tightening force to the worm 9, so that the meshing force between the worm 9 and the worm wheel 8 can be adjusted adaptively, and assembly stress can be avoided.

[0024] In this embodiment, as shown in the attached Figure 2 , an end cover 13 and a locking nut 14 are further provided inside the first housing 1. The end cover 13 cooperates with the end of the worm 9 away from the motor 10, and the locking nut 14 abuts against the lower end face of the second bearing 6. The first bearing 3 in this embodiment is a deep groove ball bearing, and the second bearing 6 is a self - aligning four - point ball bearing. The end cover 13 axially fixes the worm 9, and the locking nut 14 axially fixes the second bearing 6. An oil seal 15 can be provided inside the locking nut 14.

[0025] The above has schematically described the present invention and its embodiments. This description is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the creation of the present invention, design similar structural forms and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A worm gear meshing clearance adjustment mechanism, characterized in that: It includes a first housing for installing a worm and a second housing for installing a worm wheel. The first housing is connected to the second housing. A first bearing for sleeved on one end of the worm is arranged in the first housing. An adjusting rod is rotatably arranged in the first housing. The free end of the adjusting rod abuts against a side of the first bearing away from the worm wheel.

2. The worm gear meshing clearance adjustment mechanism according to claim 1, characterized in that: The adjusting rod is a screw rod, and the first housing is provided with a screw hole rotatably connected to the screw rod, and the center line of the screw hole is perpendicular to the axis of the first bearing.

3. The worm gear meshing clearance adjustment mechanism according to claim 1, characterized in that: The outer peripheral wall of the first bearing is sleeved with a first shaft sleeve, the first housing is provided with a mounting cavity for mounting the first shaft sleeve, and the free end of the adjusting rod passes through the first shaft sleeve and abuts against the first bearing.

4. The worm gear meshing clearance adjustment mechanism according to claim 1, characterized in that: A second bearing is also provided in the first housing. The second bearing is used to be sleeved on the outer peripheral wall of one end of the worm connected to the motor. A second shaft sleeve is sleeved on the outer peripheral wall of the second bearing.

5. An electric power steering device, characterized in that: It includes a worm wheel, a worm, a motor and a worm wheel and worm meshing clearance adjustment mechanism as described in any one of claims 1 to 4, wherein the worm wheel is located inside a first housing, the worm wheel is located inside a second housing, the worm wheel is meshed with the worm, the first bearing sleeve is arranged at one end of the worm, and the other end of the worm is connected to the motor.

6. The electric power steering device according to claim 5, characterized in that: The worm and the motor are connected via a coupling, the input end of the worm and the output shaft of the motor are respectively inserted at two ends of the coupling, and an elastic pad is sleeved on the outer peripheral wall of the coupling.

7. The electric power steering device according to claim 6, characterized in that: It also includes a spring, one end of which elastically abuts against the input end of the worm, and the other end of the spring passes through the coupling and is supported on the output shaft of the motor. The worm, the coupling, the spring and the output end of the motor are coaxially arranged.

8. The electric power steering device according to claim 5, characterized in that: An end cover and a locking nut are also provided in the first housing. The end cover cooperates with an end of the worm away from the motor, and the locking nut abuts against the lower end surface of the second bearing.

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