Electric power steering device and synchronous belt tension adjusting mechanism thereof

Abstract

The utility model discloses an electric power steering device and a synchronous belt tension adjusting mechanism thereof, the electric power steering device comprises a cam, a bearing, a roller and a positioning piece used for being movably connected with a speed reduction shell, the positioning piece is fixedly connected with the cam, and the axis of the positioning piece and the axis of the cam are not on the same straight line. The inner ring of the bearing is in fastening fit with the outer circumferential wall of the cam, the outer ring of the bearing is in fastening fit with the inner circumferential wall of the roller, and the outer circumferential wall of the roller is used for abutting against a synchronous belt in a rolling mode. When the tension force of the synchronous belt needs to be adjusted, the positioning piece is rotated, the cam is driven to rotate, the cam, the bearing and the roller form an eccentric adjusting whole, the large diameter or the small diameter of the eccentric adjusting whole abuts against the synchronous belt, then the tension force of the synchronous belt is adjusted, and after adjustment is completed, the positioning piece is fixed to the speed reduction shell again. The center distance between the driving wheel and the driven wheel does not need to be adjusted, and operation difficulty is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of steering gear, concretely relates to electric power steering device and synchronous belt tension adjusting mechanism thereof. BACKGROUND

[0002] Parallel shaft type electric power steering gear is one of the mainstream steering gears applied to the current vehicle steering system, and has the advantages of simple structure and flexible assembly. When the parallel shaft type electric power steering gear is assembled, the tension of the belt needs to be adjusted. The existing adjustment mode is as follows: the fixed position of the power assist motor is adjusted before assembly, so as to change the center distance between the driving wheel and the driven wheel, and the purpose of adjusting the belt tension is achieved. In this adjustment mode, when the fixed position of the power assist motor is searched, the power assist motor is in a suspended state, and the displacement of the motor is not easy to control, which leads to low adjustment precision of the belt tension and low assembly efficiency. SUMMARY

[0003] In view of the above technical problems, the utility model provides an electric power steering device and a synchronous belt tension adjusting mechanism thereof. The positioning member is rotated to drive the cam to rotate, so that the large diameter or small diameter of the eccentric adjusting body abuts against the synchronous belt, and the tension of the synchronous belt is adjusted without adjusting the center distance between the driving wheel and the driven wheel.

[0004] The technical scheme adopted by the utility model is as follows: a synchronous belt tension adjusting mechanism, comprising a cam, a bearing, a roller and a positioning member used for movably connecting with a reduction shell, the positioning member is fixedly connected with the cam, and the shaft center of the positioning member is not on the same straight line as the shaft center of the cam, the inner ring of the bearing is tightly matched with the outer peripheral wall of the cam, the outer ring of the bearing is tightly matched with the inner peripheral wall of the roller, and the outer peripheral wall of the roller is used for rolling abutting against the synchronous belt.

[0005] Optionally, the positioning member is a screw, and the positioning member passes through the cam and the reduction shell in sequence and is matched with a nut.

[0006] Optionally, the axial length of the roller is greater than the axial length of the bearing.

[0007] The utility model also discloses an electric power steering device, which comprises a driving wheel, a driven wheel, a driving member, a synchronous belt, a reduction shell and the synchronous belt tension adjusting mechanism described above, the driving member is coaxially connected with the driving wheel, the synchronous belt is arranged on the outer peripheral wall of the driving wheel and the driven wheel, the driving wheel, the driven wheel, the driving member and the synchronous belt are arranged in the reduction shell, the positioning member movably matches with the reduction shell, and the outer peripheral wall of the roller rolls against the synchronous belt.

[0008] Optionally, the speed reduction shell comprises a ring-shaped plate, a first sealing plate matched with one side of the ring-shaped plate, and a second sealing plate matched with the other side of the ring-shaped plate, the ring-shaped plate, the first sealing plate and the second sealing plate jointly form a cavity for accommodating the driving wheel, the driven wheel and the synchronous belt, the output end of the driving member is coaxially connected with the driving wheel through the second sealing plate, and the positioning member is mounted on the second sealing plate.

[0009] Optionally, the driven wheel is coaxially connected with a steering screw, the steering screw is arranged in a steering shell, and the steering shell is detachably connected with the speed reduction shell.

[0010] Optionally, the second sealing plate is provided with a through hole for the steering screw to pass through, the second sealing plate is provided with a plurality of first protrusions on the side away from the first sealing plate, the plurality of first protrusions are arranged in a circumferential direction of the through hole, the steering shell is provided with a plurality of second protrusions in the circumferential direction, and the first protrusions and the second protrusions are connected in one-to-one correspondence.

[0011] Optionally, the driving member is a rotary motor.

[0012] The utility model discloses beneficial effects are: positioning member and cam eccentricity set, need to adjust the tension of synchronous belt, rotate positioning member, drive cam rotation, cam, bearing, roller eccentricity adjustment whole, make eccentricity adjustment whole's big diameter or small diameter abut synchronous belt, and then adjust the tension of synchronous belt, adjust good, repositioning member fixed on the speed reduction shell can, need not to adjust the center distance between driving wheel and driven wheel, reduce the operation difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 The structure diagram of the synchronous belt tension adjusting mechanism is provided for the utility model embodiment.

[0014] Figure 2 The structure diagram of the electric power steering device is provided for the utility model embodiment.

[0015] The marks in each drawing are: 1, cam; 2, bearing; 3, roller; 4, positioning member; 5, driving wheel; 6, driven wheel; 7, driving member; 8, synchronous belt; 9, ring-shaped plate; 10, first sealing plate; 11, second sealing plate; 12, steering shell; 13, first protrusion; 14, second protrusion. DETAILED DESCRIPTION

[0016] The application will be further described in detail in combination with the drawings and embodiments.

[0017] As Figure 1As shown, the embodiment discloses a synchronous belt tensioning adjusting mechanism, which comprises a cam 1, a bearing 2, a roller 3 and a positioning piece 4 for active connection with a reduction shell, the positioning piece 4 is fixedly connected with the cam 1, and the shaft center of the positioning piece 4 is not in the same straight line with the shaft center of the cam 1, the inner ring of the bearing 2 is tightly matched with the outer peripheral wall of the cam 1, the outer ring of the bearing 2 is tightly matched with the inner peripheral wall of the roller 3, and the outer peripheral wall of the roller 3 is used for rolling abutting with the synchronous belt 8. The positioning piece 4 is eccentrically arranged with the cam 1, when the tension of the synchronous belt 8 needs to be adjusted, the positioning piece 4 is rotated to drive the cam 1 to rotate, the cam 1, the bearing 2 and the roller 3 form an eccentric adjusting whole, the large diameter or the small diameter of the eccentric adjusting whole abuts against the synchronous belt 8, and then the tension of the synchronous belt 8 is adjusted, after adjustment, the positioning piece 4 is fixed on the reduction shell, and the center distance between the driving wheel 5 and the driven wheel 6 does not need to be adjusted. The positioning piece 4 is a screw, and the positioning piece 4 passes through the cam 1 and the reduction shell in sequence and is matched with a nut. The screw is installed on the reduction shell through cooperation with the nut. The axial length of the roller 3 is greater than the axial length of the bearing 2. The contact area of the roller 3 and the synchronous belt 8 is increased.

[0018] The utility model discloses an electric power-assisted steering device, like Figure 2 As shown, comprising driving wheel 5, driven wheel 6, drive piece 7, synchronous belt 8, reduction shell and the synchronous belt 8 tensioning adjusting mechanism described above, the drive piece 7 is coaxial connection with driving wheel 5, the synchronous belt 8 is around and is arranged on the outer peripheral wall of driving wheel 5 and driven wheel 6, driving wheel 5, driven wheel 6, drive piece 7, synchronous belt 8 all are arranged in the reduction shell inside, the positioning piece 4 is active cooperation with reduction shell, the outer peripheral wall of roller 3 is rolling abutted with synchronous belt 8. Drive piece 7 drives driving wheel 5 to rotate, and driving wheel 5 drives driven wheel 6 to rotate through synchronous belt 8, when the tension of synchronous belt 8 needs to be adjusted, unscrews the nut, rotates the positioning piece 4, and the large diameter or the small diameter of eccentric adjusting whole abuts against synchronous belt 8, and the tension of synchronous belt 8 is adjusted, and the center distance between driving wheel 5 and driven wheel 6 does not need to be adjusted.

[0019] In the embodiment, as Figure 2As shown, the speed reduction housing comprises an annular plate 9, a first sealing plate 10 matched with one side of the annular plate 9, and a second sealing plate 11 matched with the other side of the annular plate 9, the annular plate 9, the first sealing plate 10 and the second sealing plate 11 form a cavity accommodating the driving wheel 5, the driven wheel 6 and the synchronous belt 8, the output end of the driving member 7 is coaxially connected with the driving wheel 5 through the second sealing plate 11, and the positioning member 4 is installed on the second sealing plate 11. The first sealing plate 10 and the second sealing plate 11 can be connected with the annular plate 9 through screws. The driven wheel 6 is coaxially connected with a steering screw, the steering screw is arranged in a steering housing 12, and the steering housing 12 is detachably connected with the speed reduction housing. The second sealing plate 11 is provided with a through hole through which the steering screw passes, the second sealing plate 11 away from the first sealing plate 10 is provided with a plurality of first protrusions 13, the plurality of first protrusions 13 are arranged in a circumferential direction of the through hole, the steering housing 12 is provided with a plurality of second protrusions 14 in the circumferential direction, and the first protrusions 13 and the second protrusions 14 are connected one by one. The first protrusions 13 and the second protrusions 14 are detachably connected through bolts. The assembly and disassembly of the driving wheel 5, the driven wheel 6, the synchronous belt 8 and the synchronous belt 8 tension adjusting mechanism are facilitated. The driving member 7 is a rotary motor.

[0020] It can be understood that the specific embodiments described above are only used to explain the related utility model, and are not limited to the utility model. In addition, it should be noted that, for the convenience of description, only the parts related to the utility model are shown in the drawings. The technical solutions in the same embodiment and the technical solutions in different embodiments can be arranged and combined to form new technical solutions without contradiction or conflict. Any equivalent structural transformation, direct or indirect application in other related technical fields, is also included in the protection scope of the utility model.

Claims

1. A synchronous belt tension adjustment mechanism, characterized in that, It includes a cam, a bearing, a roller, and a positioning element for movably connecting with the reduction gear housing. The positioning element is fixedly connected to the cam, and the axis of the positioning element is not on the same straight line as the axis of the cam. The inner ring of the bearing is fastened to the outer peripheral wall of the cam, and the outer ring of the bearing is fastened to the inner peripheral wall of the roller. The outer peripheral wall of the roller is used to roll against the synchronous belt.

2. The synchronous belt tension adjustment mechanism according to claim 1, characterized in that, The positioning element is a screw, which passes through the cam and the reduction housing in sequence and is fitted with a nut.

3. The synchronous belt tension adjustment mechanism according to claim 1, characterized in that, The axial length of the roller is greater than the axial length of the bearing.

4. An electric power steering device, characterized in that, The device includes a driving pulley, a driven pulley, a driving component, a synchronous belt, a reduction housing, and a synchronous belt tension adjustment mechanism as described in any one of claims 1 to 3. The driving component is coaxially connected to the driving pulley, the synchronous belt is wound around the outer peripheral walls of the driving pulley and the driven pulley, the driving pulley, the driven component, and the synchronous belt are all located inside the reduction housing, the positioning component is movably engaged with the reduction housing, and the outer peripheral wall of the roller rolls against the synchronous belt.

5. The electric power steering device according to claim 4, characterized in that, The deceleration housing includes an annular plate, a first sealing plate that mates with one side of the annular plate, and a second sealing plate that mates with the other side of the annular plate. The annular plate, the first sealing plate, and the second sealing plate together form a cavity that accommodates the driving wheel, the driven wheel, and the timing belt. The output end of the drive component passes through the second sealing plate and is coaxially connected to the driving wheel. The positioning component is installed on the second sealing plate.

6. The electric power steering device according to claim 5, characterized in that, The driven wheel is coaxially connected to a steering screw, which is located inside the steering housing. The steering housing and the reduction housing are detachably connected.

7. The electric power steering device according to claim 6, characterized in that, The second sealing plate has a through hole for the steering screw to pass through. The side of the second sealing plate opposite to the first sealing plate has a plurality of first protrusions. The plurality of first protrusions are arranged circumferentially along the through hole. The steering housing has a plurality of second protrusions circumferentially. The first protrusions and the second protrusions are connected in a one-to-one correspondence.

8. The electric power steering device according to claim 4, characterized in that, The driving component is a rotary motor.

Images