CN112303187A - Bearing bush, EPSc worm end part pre-tightening structure and worm and gear assembly structure - Google Patents

Abstract

The invention discloses a bearing bush, an EPSc worm end part pre-tightening structure and a worm and gear assembly structure. The bearing bush includes: the buffer part comprises a bushing body and a buffer part fixed on the bushing body; the buffer member comprises a spring piece, the spring piece is arranged at the top of the bushing body, the spring piece comprises an extending part and a fixing part, and the extending part extends obliquely downwards from two opposite sides of the fixing part. The bearing bush provides special pretightening force through deformation of the extension part of the spring piece relative to the fixed part, so that the robustness of pretightening design is enhanced, the friction torque is reduced, and the meshing noise of the worm and gear under various working conditions is reduced. The EPSc worm end part pre-tightening structure and the worm gear assembly structure have the same effects.

Description

Bearing bush, EPSc worm end part pre-tightening structure and worm and gear assembly structure

The present application claims priority from chinese patent applications 201921212066.1, 201921212057.2, 201921212059.1 filed on 7/30/2019. The present application refers to the above-mentioned chinese patent application in its entirety.

Technical Field

The invention relates to the technical field of production and manufacturing of automobile parts, in particular to a bearing bush, an EPSc worm end part pre-tightening structure and a worm and gear assembly structure.

Background

The EPSc of the automobile electric column steering system generally comprises a steering wheel, a steering column, a driving unit, an intermediate shaft, a steering gear, a tie rod and the like. The pipe column type electric power steering system is EPSc, belongs to one kind of automobile steering system, and has the main function of converting the rotation motion of the steering wheel into the left and right swinging of the wheels, so as to realize the power steering function of the automobile. The EPSc provides power-assisted torque through a power-assisted motor arranged at the driving unit, and the power-assisted torque is reduced and increased through a worm and gear speed reducing mechanism to provide corresponding power-assisted torque for a steering system, so that the designed power-assisted function is realized. Generally, the reduction mechanism employs a worm gear to increase torque.

When the worm gear and the worm are meshed in a moving mode, in order to ensure good transmission efficiency and reduce noise risks, a pre-tightening device is arranged on the worm. When the worm is installed, the pre-tightening device provides a radial force to the worm against the worm wheel, so that the worm and the worm wheel are always kept in a proper meshing position. Under the multiple operating modes of worm wheel shaking, large worm wheel excircle runout, worm wheel reverse impact worm and the like, the device can limit the swing amplitude of the worm, so that the worm is properly pressed on the worm wheel, the meshing efficiency of the speed reducing mechanism is ensured, and various noises generated by the worm wheel and the worm due to meshing are reduced.

At present, the EPSc worm gear mechanism has the problems of overlarge friction torque or overlarge free clearance and the like due to the reasons of tolerance, installation error and the like existing in part manufacturing, and finally, the rotating friction torque is overlarge to influence steering hand feeling or generate worm gear knocking noise when driving a bad road. The current solutions include a bracket bearing solution, a solution of adding a separate compression spring at one end of the worm, etc., but all have many disadvantages, such as: tolerance accumulation caused by excessive parts and low robustness; the requirement on the processing technology of the parts is too high, so that the cost is too high; the requirement on the machining precision of the parts is too high, so that the quality is not stable, and the like.

Therefore, it is necessary to design a bearing bush with a simple structure and a pre-tightening structure which can better adjust the pre-tightening effect of the worm and gear, reduce the friction torque and reduce the meshing noise of the worm and gear under various working conditions.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a bearing bush, an EPSc worm end part pre-tightening structure and a worm and gear assembly structure.

The invention solves the technical problems through the following technical scheme:

a bearing cartridge, comprising: the buffer part comprises a bushing body and a buffer part connected with the bushing body;

the buffer member comprises a spring piece, the spring piece is arranged at the top of the bushing body, the spring piece comprises an extending part and a fixing part, and the extending part extends obliquely downwards from two opposite sides of the fixing part.

Preferably, the fixed portion is erected on the top surface of the bushing body, and one end of the extending portion, which is far away from the fixed portion, abuts against two sides of the bushing body respectively.

Preferably, the fixing portion is a C-shaped clip portion.

Preferably, the outer edge of the upper piece of the C-shaped clip part is tilted upwards to form a fin, and two ends of the lower piece of the C-shaped clip part are respectively connected with the extending part.

Preferably, an end of the extension portion remote from the fixing portion is bent toward the bushing body to form a bent portion.

Preferably, the fixed portion is fixed to the top surface of the bushing body, and one end of the extending portion, which is far away from the fixed portion, is tilted outward with respect to both sides of the bushing body.

Preferably, the buffer member further includes a top elastic pad disposed on the top surface of the bushing body, and the fixing portion is provided with a hole that is fitted over the top elastic pad so that the fixing portion is fixed with respect to the bushing body.

Preferably, an end of the extension portion remote from the fixing portion is provided with a contact projection.

Preferably, the buffer further comprises: the top elastic pad is fixed on the top surface of the bearing bush and/or the side elastic pads are fixed on two side surfaces of the bearing bush.

Preferably, the side elastic member is a concave-shaped member.

Preferably, the side elastic member extends along a circumferential direction of the bushing body.

Preferably, the bushing body is a circular ring shaped member.

An EPSc worm end pretensioning arrangement comprising a bearing bush as described above.

Preferably, the EPSc worm end pretensioning structure further comprises a bearing, the bearing being disposed inside the bearing bush.

A worm gear assembly comprising an EPSc worm end pretensioning arrangement as described above.

Preferably, the worm and gear assembly structure further comprises a bearing support module arranged at one end of the worm, and the EPSc worm end pre-tightening structure is arranged in the bearing support module and between the worm and the bearing support module.

Preferably, the bearing support module is provided at the small end of the worm.

Preferably, the fixed part is erected on the top surface of the bushing body, and one end of the extending part, which is far away from the fixed part, abuts against two sides of the bushing body respectively;

the fixing portion is fixed to the bearing support module.

Preferably, the fixing portion is a C-shaped clip portion;

the fixing portion is clamped to an upper portion of the bearing support module.

Preferably, the fixed part is fixed on the top surface of the bushing body, and one end of the extending part, which is far away from the fixed part, is tilted outwards relative to two sides of the bushing body;

the bearing support module is characterized in that insertion holes are formed in two sides of an inner hole of the bearing support module, the bearing bush is arranged in the inner hole, the extending portion is inserted into the insertion holes, and the top surface of the bearing bush is abutted to the top surface of the inner hole.

An improved bearing bush of an EPSc worm end pre-tightening structure, comprising: the rubber pad is divided into a top rubber pad and a side rubber pad, the top rubber pad is injected at the top of the shell, the side rubber pads are injected at two sides of the shell, and the spring piece is erected on the outer side face of the shell above the side rubber pads; the spring piece comprises a C-shaped clamping part and two wings, the outer edge of the upper piece of the C-shaped clamping part is tilted upwards to form a warped piece, two ends of the lower piece of the C-shaped clamping part are respectively connected with the top ends of the two wings, the bottom ends of the two wings are bent inwards to form bent parts, and the bent parts are tightly attached to the shell, so that the C-shaped clamping part is suspended above the top rubber pad.

Preferably, the C-shaped clamp portion of the spring plate is embedded and fixed on a shell of the driving device, the end portion of the worm is divided into a large end and a small end, a pendulum bearing is sleeved on the large end, the pendulum bearing and the large end are in interference fit, a deep groove ball bearing is arranged on the small end in interference press fit, the deep groove ball bearing is sleeved in the bearing bush, and the outer edge of the pendulum bearing is fixed on the shell of the driving device.

Preferably, the top rubber pad is in a shape of a circular sheet, and the side rubber pads are in a shape of a concave.

Preferably, the spring plate is a leaf spring.

A bearing bush for an EPSc worm end radial pre-tightening structure comprises a shell, rubber pads and spring pieces, wherein the rubber pads are divided into top rubber pads and side rubber pads, the top rubber pads are injected on the top of the shell, the side rubber pads are injected on two sides of the shell, and the spring pieces are embedded and fixed on the top of the shell;

the spring piece comprises a middle part and two wings, the two wings are respectively fixed on two sides of the middle part by utilizing transition areas, the middle part is a plane rectangle, the two wings are in a downward-inclined strip shape, and the free ends of the two wings are respectively fixed with concave reeds.

Preferably, the end portion of the worm is divided into a large end and a small end, a pendulum bearing is sleeved on the large end, the pendulum bearing and the large end are in interference fit, a bearing is sleeved on the small end, the bearing bush is sleeved on the outer edge of the bearing, and the outer edge of the pendulum bearing is fixed on a shell of the driving device.

Preferably, the top of the shell is provided with a raised platform, and the middle part of the spring piece is fixed on the raised platform by the top rubber pad.

Preferably, the top rubber pad is disc-shaped.

Preferably, the lateral rubber pad is in a shape of a concave.

Preferably, the spring plate is a leaf spring.

A worm gear assembly structure comprising: the shell is a separable shell, the shell comprises a worm wheel shell, the worm shell, a connecting support shell, a plastic end cover and a bearing support module, the worm shell is fixed above the worm wheel shell, one end of the worm shell is fixed with the connecting support shell, the worm shell is communicated with the worm wheel shell and the connecting support shell, the plastic end cover is fixedly installed on the worm wheel shell, the other end of the worm shell is connected with the bearing support module through screws, the worm wheel is installed in the worm wheel shell, the worm is installed in the worm shell, the worm wheel and the worm are meshed with each other, the connecting support shell is connected with a steering column support, and the pre-tightening structure is arranged at one end of the worm, and a pendulum bearing is sleeved at the other end of the worm.

Preferably, the plastic end cover is provided with a mounting through hole, a metal ring is press-mounted in the mounting through hole in an interference manner, and a self-tapping screw penetrates through the metal ring to fix the plastic end cover on the surface of the worm gear shell.

Preferably, the pretensioning structure comprises a bearing and a bearing bush;

the bearing sleeve is arranged on the worm, the bearing bush sleeve is arranged on the bearing, the bearing bush comprises a shell, a rubber pad and a spring piece, the rubber pad is divided into a top rubber pad and a side rubber pad, the top rubber pad is injected at the top of the shell, the side rubber pads are injected at two sides of the shell, and the spring piece is arranged on the shell.

Preferably, the spring piece comprises a middle part and two wings, the two wings are respectively fixed on two sides of the middle part by using transition areas, the middle part is a plane rectangle, the two wings are in a downward-inclined strip shape, and the free ends of the two wings are respectively fixed with concave reeds.

Preferably, the middle part of the spring plate is fixed on the raised platform of the shell by the top rubber pad.

Preferably, the spring piece consists of a C-shaped clip part and two wing inclined sides, the outer edge of an upper piece of the C-shaped clip part is tilted upwards to form a warped piece, two ends of a lower piece of the C-shaped clip part are respectively connected with the top ends of the two wing inclined sides, and the bottom ends of the two wing inclined sides are bent inwards to form bent parts.

Preferably, the C-shaped clamp-shaped part of the spring plate is embedded and fixed on the worm shell, and the bent part is tightly attached to the shell, so that the C-shaped clamp-shaped part is suspended and fixed above the top rubber pad.

Preferably, the top rubber pad is in a shape of a circular sheet, and the side rubber pads are in a shape of a concave.

Preferably, the spring plate is a leaf spring.

Preferably, the inner hole of the bearing support module is a square hole or a circular hole.

The positive progress effects of the invention are as follows:

the bearing bush provides a special pretightening force as shown in the following figure 5 through the deformation of the extension part of the spring sheet relative to the fixed part, so that the robustness of a pretightening design is enhanced, the friction torque is reduced, and the meshing noise of the worm and gear under various working conditions is reduced. The EPSc worm end part pre-tightening structure and the worm gear assembly structure have the same effects.

Compared with the prior art, one end of the spring piece is in contact with the shell, and the other end of the spring piece is tightly pressed on the bushing, so that the spring piece is deformed when the worm swings, thereby applying pretightening force, and the worm is always pressed to the radial force of the worm wheel, thereby enhancing the robustness of the pretightening design, reducing the friction torque and reducing the meshing noise of the worm wheel and the worm under various working conditions.

Drawings

Fig. 1 is a perspective view schematically showing a bearing cartridge according to embodiment 1 of the present invention.

Fig. 2 is a schematic perspective view of a spring plate according to embodiment 1 of the present invention.

Fig. 3 is a schematic view of a structure in which a bearing cartridge is fitted to a housing according to embodiment 1 of the present invention.

Fig. 4 is an exploded structural view of a worm and gear assembly structure according to embodiment 1 of the present invention.

FIG. 5 is a graph of the amount of compression versus force for a spring plate according to embodiment 1 of the present invention.

Fig. 6 is a perspective view schematically illustrating a bearing cartridge according to embodiment 2 of the present invention.

Fig. 7 is a perspective view of a spring plate according to embodiment 2 of the invention.

Fig. 8 is a schematic view of a structure in which a bearing cartridge is fitted to a housing according to embodiment 2 of the present invention.

Fig. 9 is an exploded structural view of a worm and gear assembly structure according to embodiment 2 of the present invention.

FIG. 10 is a graph of the amount of compression versus force for a spring plate according to embodiment 2 of the present invention.

Fig. 11 is a schematic structural view of a worm and gear assembly structure according to embodiment 3 of the present invention.

Fig. 12 is another structural schematic view of a worm and gear assembly structure according to embodiment 3 of the present invention.

Fig. 13 is a perspective view schematically illustrating a bearing cartridge according to embodiment 3 of the present invention.

Fig. 14 is a perspective view of the spring plate in fig. 13.

Fig. 15 is a schematic structural view of a bearing cartridge and a bearing support module according to embodiment 3 of the present invention.

FIG. 16 is a graph of the amount of compression versus force for a spring plate according to embodiment 3 of the present invention.

Fig. 17 is a perspective view schematically illustrating a bearing cartridge according to embodiment 4 of the present invention.

Fig. 18 is a perspective view of the spring plate in fig. 16.

Fig. 19 is a schematic view of a structure in which a bearing cartridge is fitted with a bearing support module according to embodiment 4 of the present invention.

Detailed Description

The present invention is further illustrated by way of example and not by way of limitation in the scope of the described embodiments in connection with the accompanying drawings.

Example 1

Referring to fig. 1-4, the embodiment provides an improved bearing bush of an EPSc worm end pre-tightening structure, which includes a housing, a rubber pad and a spring leaf, wherein the rubber pad is divided into a top rubber pad 1 and a side rubber pad 2, the top rubber pad 1 is injection-molded on the top of the housing 3, the side rubber pads 2 are injection-molded on two sides of the housing 3, and the spring leaf 4 is erected on the outer side surface of the housing 3 above the side rubber pads 2; the spring piece 4 consists of a C-shaped clamp part 4-1 and two wings 4-2, the outer edge of the upper piece of the C-shaped clamp part 4-1 is tilted upwards to form a fin 4-3, two ends of the lower piece of the C-shaped clamp part 4-1 are respectively connected with the top ends of the two wings 4-2, the bottom ends of the two wings 4-2 are bent inwards to form a bent part 4-4, and the bent part 4-4 is tightly attached to the shell 3, so that the C-shaped clamp part 4-1 is suspended above the top rubber pad 1.

Referring to fig. 3, in this embodiment, the C-shaped clamp portion 4-1 of the spring piece 4 is fixed to the housing 5 in an embedded manner, the end portion of the worm 6 that clamps the housing 5 is divided into a large end and a small end, the large end is sleeved with the pendulum bearing 7, the pendulum bearing 7 and the large end are in interference fit, the small end is press-fitted with the deep groove ball bearing 8 in interference fit, the deep groove ball bearing 8 is further sleeved into the bearing bushing 9, the outer edge of the pendulum bearing 7 is fixed to the housing 5 of the driving device, the worm 6 can swing back and forth with the pendulum bearing 7 as a fulcrum, the radial play of the pendulum bearing 7 is large, and the inner race adopts a special circular arc transition, and when the worm and gear are engaged, the pendulum bearing 7 will effectively guide the worm 6 to swing at a certain angle relative to the housing 5 on the axis.

In the embodiment, the top rubber pad 1 is in a circular sheet shape, the side rubber pad 2 is in a concave shape, when the worm 6 swings left and right greatly, the bulges at the two ends of the side rubber pad 2 contact the shell 5 firstly, and the worm 6 is buffered firstly due to small contact surface and small rigidity. When the worm 6 continues to swing, the middle part of the rubber finally presses the shell in a large area, and buffering with high rigidity is provided, so that the noise risk of the worm 6 knocking the shell is reduced in two steps, and meanwhile, a hard limit point is provided for the swing of the worm 6.

When the worm 6 swings, the bearing bush 9 swings along with the worm, when the worm 6 swings left and right, the lateral rubber pads 2 and the spring pieces 4 limit and buffer the movement, when the worm 6 swings up and down, the upper ends of the spring pieces 4 abut against the shell 5, the two ends of the spring pieces press the bearing bush 9, the bearing bush 9 deforms under stress, damping is provided, and the movement trend of the spring pieces far away from the worm wheel is limited.

In the embodiment, the spring piece 4 is a leaf spring, the relation between the elastic force and the displacement (compression amount) of the leaf spring is marked by a solid line shown in fig. 5, the spring force and the displacement curve of the leaf spring are different from those of other springs in that the compression rigidity can be reduced after the compression displacement reaches a certain value, so that the pretightening force of the spring is basically stable in a large displacement range, and the compression amount fluctuates greatly when the spring is assembled in place due to various accumulated tolerances in the assembling process. If a common spring is adopted for pre-tightening, the pre-tightening force provided can fluctuate greatly, and the preset pressing force cannot be well achieved, as shown by the broken line stress of fig. 5. In this case, the spring with this shape can also maintain the pretensioning force within a predetermined range even with large assembly tolerances.

In addition, the shape of the spring piece 4 is specially designed, so that the stress direction of the bearing bush 9 always points to the central axis of the worm 6. When the worm 6 swings, the spring piece 4 can compress the bearing bush 9 from the upper direction and the left direction and the right direction through deformation, so that the free swinging amplitude of the worm 6 in a certain range is allowed, the swinging of the worm 6 is well limited, and damping is provided. Meanwhile, the required pretightening force can be adjusted by adjusting the rigidity of the spring piece 4, so that the meshing requirements of various worm gears and worms are met.

Example 2

Referring to fig. 6-9, the embodiment provides a bearing bush for a worm end radial pre-tightening structure of EPSc, which includes a housing 6-1, rubber pads and spring pieces 6-4, wherein the rubber pads are divided into a top rubber pad 6-2 and a side rubber pad 6-3, the top rubber pad 6-2 is injection-molded on the top of the housing 6-1, the side rubber pads 6-3 are injection-molded on two sides of the housing 6-1, and the spring pieces 6-4 are embedded and fixed on the top of the housing 6-1;

the spring piece 6-4 comprises a middle part 6-4-1 and two wings 6-4-2, the two wings 6-4-2 are respectively fixed on two sides of the middle part 6-4-1 by utilizing transition areas 6-4-3, the middle part 6-4-1 is a plane rectangle, the two wings 6-4-2 are in a downward-inclined strip shape, and the free ends of the two wings 6-4-2 are respectively fixed with concave reeds 6-4-4.

In the embodiment, the end part of the worm 1 is divided into a large end 2 and a small end 3, the large end 2 is sleeved with a pendulum bearing 4, the pendulum bearing 4 is in interference fit with the large end 2, the small end 3 is sleeved with a bearing 5, the outer edge of the bearing 5 is sleeved with a bearing bush 6, the outer edge of the pendulum bearing 4 is fixed on a shell 7 of the driving device, the radial clearance of the pendulum bearing 4 is large, the inner ring raceway adopts special circular arc transition, and when the worm and gear are meshed to work, the pendulum bearing 4 can effectively guide the worm to enable the worm to swing on the axis of the worm and gear at a certain angle relative to the shell 7.

In this embodiment, the top of the shell 6-1 is provided with a raised platform, and the middle part 6-4-1 of the spring piece 6-4 is fixed on the raised platform by a top rubber pad 6-2.

In this embodiment, the top rubber pad 6-2 is a disk.

In the embodiment, the lateral rubber pad 6-3 is concave, when the worm swings left and right greatly, the bulges at the two ends of the lateral rubber pad 6-3 contact the shell 6-1 firstly, the worm is buffered firstly due to small contact surface and small rigidity, and finally the middle part of the lateral rubber pad 6-3 presses the shell 6-1 in a large area to provide buffer with larger rigidity when the worm swings continuously, so that the noise risk of the worm knocking the shell is reduced in two steps, and a hard limiting point is provided for the worm swinging.

The spring plate 6-4 in this embodiment is a leaf spring, and the relationship between the spring force and the displacement is shown in fig. 10, and the difference between the spring force and the displacement curve of the leaf spring and other springs is that the compression stiffness becomes small when the compression displacement reaches a certain value, as shown by the solid line in fig. 10. Therefore, the pretightening force of the spring can be ensured to be basically stable within a large displacement range. During assembly, the amount of compression fluctuates widely as the spring is assembled into position due to various cumulative tolerances. If a common spring is used for pre-tightening, the pre-tightening force provided will also fluctuate greatly, and the preset pressing force cannot be achieved well, as shown by the broken line stress in fig. 10. In this case, the spring with this shape can also maintain the pretensioning force within a predetermined range even with large assembly tolerances.

When the worm is installed, the bearing bush 6 is wholly sleeved into the outer ring of the worm small-end bearing 5 and then is installed in the shell 7 together, when the worm swings, the bearing bush 6 swings along with the worm, and when the worm swings left and right, the side rubber pads 6-3 and the spring pieces 6-4 limit and buffer the movement; when the worm rocks up and down, the upper end of the spring piece 6-4 is propped against the shell 7, and the two ends of the spring piece are pressed on the shell 6-1 and deform under stress, so that damping is provided, and the movement trend of the spring piece far away from the worm wheel is limited.

In addition, after the shape of the spring piece 6-4 is matched with the shell 6-1, not only can up-and-down swinging pretightening force be provided, but also left-and-right swinging pretightening force can be provided, the free swinging amplitude of the worm in a certain range is allowed, the swinging of the worm is well limited, damping is provided, and meanwhile, the required pretightening force can be adjusted by adjusting the rigidity of the spring piece 6-4, so that the meshing requirements of various worm gears and worms are met.

Example 3

Referring to fig. 11 to 16, the present embodiment provides a worm gear assembly structure including: the worm wheel, the worm, the pretension structure and the shell are separable shells, wherein the shell comprises a worm wheel shell 1, a worm shell 2, a connecting support shell 3, a plastic end cover 4 and a bearing supporting module 5, the worm shell 2 is fixed above the worm wheel shell 1, one end of the worm shell 2 is fixed with the connecting support shell 3, the worm shell 2 is communicated with the worm wheel shell 1 and the connecting support shell 3, the plastic end cover 4 is fixedly installed on the worm wheel shell 1, the other end of the worm shell 2 is connected with the bearing supporting module 5 through screws, the worm wheel 6 is installed in the worm wheel shell 1, the worm 7 is installed in the worm shell 2, the worm wheel 6 and the worm 7 are meshed with each other, the connecting support shell 3 is connected with a steering column support, the pretension structure is arranged at one end of the worm 7, and the pendulum bearing 8 is sleeved at the other end.

In the embodiment, the plastic end cover 4 is provided with a mounting through hole, the metal ring 9 is press-fitted in the mounting through hole in an interference manner, and the self-tapping screw penetrates through the metal ring 9 to fix the plastic end cover 4 on the surface of the worm gear housing 1.

In this embodiment, the pre-tightening structure includes a bearing 10 and a bearing bush 11, the bearing 10 is sleeved on the worm 7, and the bearing bush 11 is sleeved on the bearing 10. The bearing bush 11 comprises a shell (bush body) 11-1, rubber pads and spring pieces 11-2, wherein the rubber pads are divided into a top rubber pad 11-3 and a side rubber pad 11-4, the top rubber pad 11-3 is injected on the top of the shell 11-1, the side rubber pads 11-4 are injected on two sides of the shell 11-1, and the spring pieces 11-2 are installed on the shell 11-1. The rubber pad and the spring piece are buffer parts with a buffering effect. The embodiment uses a rubber pad, but alternatively, other alternative materials of elastic pads may be used to achieve cushioning of the top and sides of the bearing bushing. The spring plate is arranged between the shell 11-1 and the bearing support module 5. As is apparent from fig. 13, the spring piece 11-2 is provided on the top of the housing 11-1, and the spring piece 11-2 includes an extension portion and a fixing portion, the extension portion extending obliquely downward from opposite sides of the fixing portion.

Fig. 13 illustrates the bearing bush 11 of the present embodiment. The bearing cartridge 11 includes a housing 11-1 and a buffer member attached to the housing 11-1.

As shown in fig. 14, the spring plate 11-2 includes a middle portion 11-2-1a (fixed portion) and two wings 11-2-2a (extended portion), the two wings 11-2-2a are respectively fixed on two sides of the middle portion 11-2-1a by using transition regions, the middle portion 11-2-1a is a plane rectangle, the two wings 11-2-2a are downward inclined strips, and the free ends (the ends of the extended portions far from the fixed portion) of the two wings 11-2-2a are respectively fixed with concave reeds 11-2-3 a. The concave spring piece forms a protrusion (contact protrusion) by being concave on the surface facing the housing 11-1, and the contact area of the concave spring piece 11-2-3a and the housing can be reduced by the protrusion, so that the friction force between the concave spring piece 11-2-3a and the housing can be reduced, and the concave spring piece 11-2-3a can slide relative to the housing. The free ends of the two wings 11-2-2a are tilted outward with respect to both sides of the housing 11-1.

In the bearing bush, the middle portion 11-2-1a of the spring piece 11-2 is fixed on the boss platform by the top rubber pad 11-3. Specifically, the middle portion 11-2-1a of the spring piece 11-2 is provided with a hole, and the spring piece 11-2 is fixed relative to the top rubber pad 11-3 by the cooperation of the top rubber pad 11-3 and the hole.

In the embodiment, the top rubber pad 11-3 is in a circular sheet shape, the side rubber pad 11-4 is in a concave shape, when the worm swings left and right greatly, the bulges at the two ends of the side rubber pad contact the shell firstly, the worm is buffered in the first step due to small contact surface and small rigidity, and when the worm swings continuously, the middle part of the side rubber pad presses the shell in a large area finally, so that the buffer with larger rigidity is provided, the noise risk that the worm knocks the shell is reduced in two steps, and meanwhile, a hard limiting point is provided for the swing of the worm. As shown, the lateral rubber pads 11-4 extend along the circumferential direction of the housing 11-1, and the housing 11-1 is a circular ring-shaped member.

The spring plate 11-2 in this embodiment is a leaf spring, and the relationship between the spring force and the displacement (compression amount or deformation amount) is shown in fig. 16, and the spring force and displacement curve of the leaf spring is different from that of other springs in that the compression stiffness becomes small when the compression displacement reaches a certain value, as shown by the solid line in fig. 16. Therefore, the pretightening force of the spring can be ensured to be basically stable within a large displacement range. During assembly, the amount of compression fluctuates widely as the spring is assembled into position due to various cumulative tolerances. If a common spring is used for pre-tightening, the pre-tightening force provided can fluctuate greatly, and the preset pressing force cannot be well achieved, as shown by the broken line stress in fig. 16. In this case, the spring with this shape can also maintain the pretensioning force within a predetermined range even with large assembly tolerances.

The inner hole of the bearing support module 5 in this embodiment is an adjustable hole, and may be a square hole, a circular hole, or other complex-shaped inner holes.

The pre-tightening structure is arranged in the bearing support module 5 and between the worm and the bearing support module 5. As shown in fig. 15, insertion holes 5-1 are formed at both sides of an inner hole of the bearing support module 5, a bearing bush is provided in the inner hole, two wings 11-2-2a are inserted into the insertion holes 5-1, and a top surface of the bearing bush abuts against a top surface of the inner hole, thereby confining the spring piece 11-2 between an upper portion of the bearing support module 5 and the housing 11-1. When the worm vibrates or deflects, the top rubber pad 11-3 and the side rubber pads 11-4 buffer the bearing bush in the vertical direction and the horizontal direction, namely, realize the pretightening adjustment of the worm (preferably the small end of the worm), and meanwhile, the spring pieces 11-2 abut against the wall surface of the insertion hole 5-1, so that the bearing bush is buffered in the vertical direction and the horizontal direction, namely, realize the pretightening adjustment of the worm (preferably the small end of the worm). Since the insertion hole 5-1 extends obliquely downward at an angle different from the angle of inclination of the two wings 11-2-2a of the spring plate 11-2, i.e., the extending direction of the insertion hole 5-1 and the extending direction of the two wings 11-2-2a form a certain angle, when the housing 11-1 moves left and right or moves up and down, the two wings 11-2-2a deform by abutting against the inner wall of the insertion hole 5-1, thereby achieving the buffering of the bearing bush in the up-down direction and the left-right direction.

In specific implementation, the metal ring is in interference fit with the plastic end cover through press fitting, then the plastic end cover is matched and fixed with the worm gear shell through 3 self-tapping screws, and the press-fitted metal ring is mainly used for bearing the screwing torque of the self-tapping screws and protecting the plastic end cover.

Referring to fig. 11, the worm wheel of the present embodiment does not require special machining of threaded holes in the housing, and different overall interface sizes are met by using different plastic end cap designs, so that the housing body can remain unchanged for use in a plurality of projects.

The bearing support module is fixed on the shell body 4 through 3 or 4 screws, so that the shape of an inner hole of the bearing support module is selectively adjusted according to the adopted bearing under the condition that the outer structure of the shell is not changed, and the bearing assembled inside obtains pretightening force in different directions to restrain a worm gear and worm transmission mechanism.

The shell of the embodiment adopts a modular design, different vehicle types can support the module by matching different plastic end covers and bearing seats, and the main body part of the shell is kept unchanged, so that the design variation is greatly reduced, the labor cost and the part purchasing cost are reduced, the flexible design is realized, the management is convenient, and the main body part of the shell is kept unchanged, so that the shell can be applied to a plurality of projects, the development period is greatly reduced, and the project period is shortened; the whole complex shell design is changed into the modularized shell composed of a plurality of small parts at present, so that the design of a supplier mold can be simplified, the difficulty in manufacturing the shell is greatly reduced, the product percent of pass is greatly improved, and the quality stability and the robustness are improved; the detachable bearing seat support module can provide different pretightening forces for the bearing by changing the design structure of the support, and is favorable for assembling the bearing seat.

The pendulum bearing in the embodiment has larger radial play, and the inner ring raceway adopts special circular arc transition, so that when the worm gear and the worm are meshed to work, the pendulum bearing can effectively guide the worm to swing at a certain angle relative to the shell on the axis of the pendulum bearing.

When the pre-tightening structure of the embodiment is installed, the bearing bush is wholly sleeved into the outer ring of the bearing at the small end of the worm and then is installed into the shell together, when the worm swings, the bearing bush swings along with the worm, and when the worm swings left and right, the side rubber pads and the spring pieces limit and buffer the movement; when the worm rocks up and down, the upper end of the spring piece props against the shell, the two ends of the spring piece are pressed on the shell, the spring piece deforms under stress, damping is provided, and the movement trend of the spring piece far away from the worm wheel is limited. In the implementation, the pre-tightening device is adjusted from the large end of the worm to the small end of the worm, so that a better pre-tightening effect on the worm and gear can be realized. And the large end of the worm is provided with a pendulum bearing.

Example 4

The present embodiment provides a worm gear assembly structure, which is substantially the same as the worm gear assembly structure of embodiment 3, except that:

as shown in fig. 17 to 19, the spring plate 11-2 of the present embodiment is composed of a C-shaped clip portion 11-2-1b (a fixed portion) and two wing inclined sides 11-2-2b (extended portions), an outer edge of an upper piece of the C-shaped clip portion 11-2-1b is tilted upward to form a fin 11-2-3b, two ends of a lower piece of the C-shaped clip portion 11-2-1b are respectively connected to top ends of the two wing inclined sides 11-2-2b, and bottom ends of the two wing inclined sides 11-2-2b (ends of the extended portions far from the fixed portion) are bent inward (toward the bushing body) to form a bent portion 11-2-4 b. The bending part is a smooth hook-shaped structure. By forming the bent portion, further cushioning can be formed without forming a sharp portion that damages the bushing body. Alternatively, the bottom ends of the two wing inclined sides 11-2-2b may not be formed with a bent portion, and may be flat, etc., without affecting the implementation of the present invention. The C-shaped clamp portion 11-2-1b is erected above the top surface of the bushing body.

In this embodiment, the C-shaped clamp portion 11-2-1b of the spring piece 11-2 is fitted and fixed to the housing. The spring piece 11-2 is tightly held on the housing (bearing support module 5) by elastic clamping between the upper piece and the lower piece of the C-shaped clamp portion 11-2-1 b. The upper part of the bearing support module 5 may also form a recess for the C-shaped clamp portion 11-2-1b to clamp, and the recess may further achieve the position limitation of the C-shaped clamp portion 11-2-1b in the left-right direction.

The bent part 11-2-4b is tightly attached to the shell 11-1, so that the C-shaped clamp-shaped part 11-2-1b is suspended and fixed above the top rubber pad 11-3.

In specific implementation, the structure of the spring plate shown in embodiment 3 or 4 can be selectively adopted, the spring plate shown in embodiment 3 or 4 can provide pre-tightening force for up-and-down swinging, and can also provide pre-tightening force for left-and-right swinging, so that the free swinging amplitude of the worm in a certain range is allowed, the swinging of the worm is well limited, damping is provided, and meanwhile, the required pre-tightening force can be adjusted by adjusting the rigidity of the spring plate, so that the meshing requirements of various worm gears and worms are met.

In the description of the present invention, it is to be understood that, for the convenience of description, the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, that is, orientations or positions or relative positions only when the members and devices are in the postures shown in the drawings, and do not indicate or imply that the devices or elements referred to must have the specific orientations, be configured and operated in the specific orientations as described in the description of the present invention at any time and in any case, and thus, should not be construed as limiting the present invention in this respect.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims (40)

1. A bearing cartridge, comprising: the buffer part comprises a bushing body and a buffer part connected with the bushing body;

the buffer member comprises a spring piece, the spring piece is arranged at the top of the bushing body, the spring piece comprises an extending part and a fixing part, and the extending part extends obliquely downwards from two opposite sides of the fixing part.

2. The bearing bushing of claim 1, wherein the fixed portion is erected above the top surface of the bushing body, and one ends of the extension portions, which are away from the fixed portion, abut against both sides of the bushing body, respectively.

3. The bearing cartridge as in claim 2, wherein the fixed portion is a C-shaped clip portion.

4. The bearing bush according to claim 3, wherein an outer edge of the upper piece of the C-shaped clamp portion is raised upward to form a fin, and both ends of the lower piece of the C-shaped clamp portion are respectively connected to the extension portions.

5. The bearing bushing according to claim 2, wherein an end of the extension portion remote from the fixing portion is bent toward the bushing body to form a bent portion.

6. The bearing bush according to claim 1, wherein the fixed portion is fixed to the top surface of the bush body, and an end of the extension portion remote from the fixed portion is turned outward with respect to both sides of the bush body.

7. The bearing cartridge of claim 6, wherein said buffer member further comprises a top resilient pad provided on a top surface of said cartridge body, said stationary portion being provided with a hole, said hole being fitted over said top resilient pad to secure said stationary portion relative to said cartridge body.

8. The bearing cartridge as claimed in claim 1, wherein an end of the extension portion remote from the fixing portion is provided with a contact projection.

9. The bearing cartridge as in claim 1, wherein the buffer further comprises: the top elastic pad is fixed on the top surface of the bearing bush and/or the side elastic pads are fixed on two side surfaces of the bearing bush.

10. The bearing cartridge as in claim 9, wherein the lateral spring member is a "female" shaped member.

11. The bearing cartridge as in claim 10, wherein the lateral spring member extends along a circumferential direction of the cartridge body.

12. The bearing bushing of claim 1, wherein the bushing body is a circular ring-shaped member.

13. An EPSc worm end pretensioning arrangement, characterised in that it comprises a bearing bush according to any one of claims 1 to 12.

14. The EPSc worm end pretensioning structure according to claim 13, further comprising a bearing disposed inside the bearing bushing.

15. A worm gear assembly comprising an EPSc worm end pretensioning arrangement according to claim 13 or claim 14.

16. The worm and gear assembly as claimed in claim 15, further comprising a bearing support module disposed at one end of the worm, wherein the EPSc worm end pretension structure is disposed in the bearing support module and between the worm and the bearing support module.

17. The worm gear assembly structure as claimed in claim 16, wherein the bearing support module is provided to the small end of the worm.

18. The worm gear assembly structure as claimed in claim 16, wherein the fixing portion is erected on a top surface of the bushing body, and one ends of the extension portions, which are away from the fixing portion, abut against both sides of the bushing body, respectively;

the fixing portion is fixed to the bearing support module.

19. The worm gear assembly structure as claimed in claim 18, wherein the fixing portion is a C-shaped clip portion;

the fixing portion is clamped to an upper portion of the bearing support module.

20. The worm gear assembly structure as claimed in claim 16, wherein the fixing portion is fixed to a top surface of the bushing body, and an end of the extension portion remote from the fixing portion is turned up outward with respect to both sides of the bushing body;

the bearing support module is characterized in that insertion holes are formed in two sides of an inner hole of the bearing support module, the bearing bush is arranged in the inner hole, the extending portion is inserted into the insertion holes, and the top surface of the bearing bush is abutted to the top surface of the inner hole.

21. An improved bearing bush of an EPSc worm end pre-tightening structure, comprising: casing, rubber pad and spring leaf, its characterized in that: the rubber pad is divided into a top rubber pad and a side rubber pad, the top rubber pad is injected at the top of the shell, the side rubber pads are injected at two sides of the shell, and the spring leaf is erected on the outer side surface of the shell above the side rubber pads; the spring piece comprises a C-shaped clamping part and two wings, the outer edge of the upper piece of the C-shaped clamping part is tilted upwards to form a warped piece, two ends of the lower piece of the C-shaped clamping part are respectively connected with the top ends of the two wings, the bottom ends of the two wings are bent inwards to form bent parts, and the bent parts are tightly attached to the shell, so that the C-shaped clamping part is suspended above the top rubber pad.

22. The improved EPSc worm end pretension configuration bearing bushing as claimed in claim 21 wherein: the C-shaped clamp-shaped part of the spring piece is embedded and fixed on a shell of the driving device, the end part of the worm is divided into a large end and a small end, a pendulum bearing is sleeved on the large end, the pendulum bearing and the large end are in interference fit, a deep groove ball bearing is arranged on the small end in interference press fit, the deep groove ball bearing is sleeved in the bearing bushing, and the outer edge of the pendulum bearing is fixed on the shell of the driving device.

23. The improved EPSc worm end pretension configuration bearing bushing as claimed in claim 21 wherein: the top rubber pad is in a circular sheet shape, and the side rubber pads are in a concave shape.

24. An improved EPSc worm end pretension configuration bearing bushing according to claim 21, wherein: the spring piece is a leaf spring.

25. The utility model provides a bearing bush that is used for radial pretension structure of EPSc's worm tip, includes casing, rubber pad and spring leaf, its characterized in that: the rubber pad is divided into a top rubber pad and a side rubber pad, the top rubber pad is injected at the top of the shell, the side rubber pads are injected at two sides of the shell, and the spring pieces are embedded and fixed at the top of the shell;

the spring piece comprises a middle part and two wings, the two wings are respectively fixed on two sides of the middle part by utilizing transition areas, the middle part is a plane rectangle, the two wings are in a downward-inclined strip shape, and the free ends of the two wings are respectively fixed with concave reeds.

26. The bearing bushing for a worm end radial pretension configuration for EPSc as in claim 25, wherein: the end part of the worm is divided into a large end and a small end, a pendulum bearing is sleeved on the large end, the pendulum bearing and the large end are in interference fit, a bearing is sleeved on the small end, the outer edge of the bearing is sleeved with the bearing bush, and the outer edge of the pendulum bearing is fixed on a shell of the driving device.

27. The bearing bushing for a worm end radial pretension configuration for EPSc as in claim 25, wherein: the top of the shell is provided with a raised platform, and the middle part of the spring piece is fixed on the raised platform by the top rubber pad.

28. The bearing bushing for a worm end radial pretension configuration for EPSc as in claim 25, wherein: the top rubber pad is in a shape of a circular sheet.

29. The bearing bushing for a worm end radial pretension configuration for EPSc as in claim 25, wherein: the lateral rubber pad is concave.

30. The bearing bushing for a worm end radial pretension configuration for EPSc as in claim 25, wherein: the spring piece is a leaf spring.

31. A worm gear assembly structure, comprising: the shell is a separable shell, and the shell comprises a worm wheel shell, a worm rod shell, a connecting support shell, a plastic end cover and a bearing supporting module, the worm shell is fixed above the worm gear shell, one end of the worm shell is fixed with the connecting bracket shell, the worm shell, the worm gear shell and the connecting bracket shell are communicated, the plastic end cover is fixedly arranged on the worm gear shell, the other end of the worm shell is connected with the bearing support module by screws, the worm wheel is arranged in the worm wheel shell, the worm is arranged in the worm shell, the worm wheel and the worm are meshed with each other, the connecting support shell is connected with the steering column support, one end of the worm is provided with a pre-tightening structure, and the other end of the worm is sleeved with a pendulum bearing.

32. The assembly structure of a worm and gear according to claim 31, wherein the plastic end cap has a mounting through hole, a metal ring is press-fitted into the mounting through hole, and a tapping screw penetrates the metal ring to fix the plastic end cap to the surface of the worm gear housing.

33. The worm gear assembly structure as claimed in claim 31, wherein the pre-tensioning structure includes a bearing and a bearing bushing;

the bearing sleeve is arranged on the worm, the bearing bush sleeve is arranged on the bearing, the bearing bush comprises a shell, a rubber pad and a spring piece, the rubber pad is divided into a top rubber pad and a side rubber pad, the top rubber pad is injected at the top of the shell, the side rubber pads are injected at two sides of the shell, and the spring piece is arranged on the shell.

34. The assembly structure of a worm gear and worm according to claim 33, wherein the spring plate includes a middle portion and two wings, the two wings are respectively fixed to both sides of the middle portion by a transition area, the middle portion is a flat rectangle, the two wings are in a downwardly inclined strip shape, and the free ends of the two wings are respectively fixed with concave reeds.

35. The worm-gear assembly structure as claimed in claim 34, wherein the middle portion of the spring plate is secured to the raised platform of the housing by the top rubber pad.

36. The assembly structure of a worm and gear according to claim 33, wherein the spring plate is composed of a C-shaped clip portion and two hypotenuses, an outer edge of an upper piece of the C-shaped clip portion is tilted upward to form a fin, two ends of a lower piece of the C-shaped clip portion are respectively connected with top ends of the two hypotenuses, and bottom ends of the two hypotenuses are bent inward to form a bent portion.

37. The worm-gear assembly structure as claimed in claim 36, wherein the C-shaped clamp portion of the spring plate is embedded and fixed on the worm casing, and the bent portion is tightly attached to the casing, so that the C-shaped clamp portion is suspended and fixed above the top rubber pad.

38. The worm-gear assembly structure as claimed in claim 33, wherein the top rubber pad is in the shape of a circular disk, and the side rubber pads are in the shape of a "concave" shape.

39. The worm gear assembly structure as claimed in claim 33, wherein the spring plate is a leaf spring.

40. The worm gear assembly structure as claimed in claim 31, wherein the inner hole of the bearing support module is a square hole or a circular hole.

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