CN204726501U - Electric boosting steering system - Google Patents

Abstract

The utility model provides an electric power steering system, which includes a deceleration mechanism, the deceleration mechanism is composed of a worm gear, and the two ends of the worm are supported by a special elastic structure, so that the worm gear mechanism is pre-biased to compensate for long-term wear and tear resulting meshing gap. The steering assist system of the utility model has the advantages of simple structure, convenient assembly and good performance.

Description

Electric Power Steering System

technical field

The utility model belongs to the technical field of automobile steering, in particular, the utility model relates to an electric power steering system with an innovative support structure.

Background technique

At present, the electric power steering system (EPS-Electric Power Steering) has gradually replaced the traditional mechanical or hydraulic power steering system and has become the development direction of the automobile steering system. The column-type electric power steering system (that is, the power-assisted motor is integrated on the steering column) is a main form of electric power steering system. Its cost is low and it is easy to install. It is now widely used in small and medium-sized vehicles. The steering power of the column steering system is provided by the motor. Since the motor generally has a high speed and a low torque, a reduction mechanism is needed to increase the output torque. At present, the commonly used reduction mechanism is a worm gear reduction device. However, due to the inevitable errors in manufacturing and assembly, there is a gap when the worm gear is meshing, and when the car is driving or turning on a bumpy road, the meshing gap will change suddenly due to the excitation of the road surface, which can produce various abnormal noises , and the change of the meshing gap of the worm gear will also affect the meshing performance of the worm gear, which will cause a feeling of pinching when driving and affect the driving comfort.

Chinese Invention Patent No. CN102765418A discloses an automatic adjustment mechanism for the gap between worm gear and worm, in which one end of the worm is supported by a self-aligning ball bearing, and the other end is supported by a spring device arranged in the counterbore of the shell, so that the meshing of the worm gear and worm The gap is compensated, but the support structure is relatively complicated and requires multiple openings on the housing.

Chinese Invention Patent Publication No. CN103818471A discloses a worm anti-abnormal noise support structure, in which the two ends of the worm are combined with the bearings through O-rings, thereby avoiding the collision noise caused by the gap. However, due to its structural characteristics, the movement of the worm Limited range, unable to compensate for increased backlash due to long-term wear.

Utility model content

The purpose of this utility model is to provide an electric power steering system, the deceleration mechanism of which has an original worm support method, has a simple structure, and can automatically compensate the meshing gap caused by durable wear.

According to an aspect of the utility model, there is provided an electric power steering system, which includes a reduction mechanism, the reduction mechanism includes a housing, a worm and a worm wheel accommodated in the housing and engaged with each other, the worm includes a first end and a second end, the first end of the worm fits in an auxiliary bearing which in turn is inserted in a bearing bush which is fixed in a hole in the housing, the The bearing bushing includes an inner ring engaged with the auxiliary bearing, an outer ring engaged with a hole in the housing, and elastic connecting ribs connecting the inner ring and the outer ring such that the inner ring radially movable relative to the outer ring, the second end of the worm fits in a main bearing which in turn is inserted in a bearing bracket comprising a body engaging the main bearing and A support for fixing to the housing, the main body is connected to the support through upper and lower elastic connecting ribs, and the support is fixed on the housing.

Optionally, the first end of the worm is interference fit with the auxiliary bearing, and the second end of the worm is interference fit with the main bearing.

Optionally, both the auxiliary bearing and the main bearing are deep groove ball bearings.

Optionally, the worm, the auxiliary bearing, the main bearing and the bearing bracket are fixed as one.

Optionally, there is play in the engagement of the auxiliary bearing with the inner race of the bearing bush.

Optionally, there is a gap between the bracket main body and the housing.

Optionally, the support has positioning blocks corresponding to the positioning holes in the housing.

Optionally, the bearing bush also has a positioning block.

Optionally, a washer is provided in the bracket body.

Optionally, the support member is fixed on the housing through a locking nut.

According to the electric power steering system of the utility model, the structure is simple and the assembly is convenient, and in the steering system, the worm is fixedly connected with the main bearing and the auxiliary bearing, which avoids the noise generated by their collision with each other, and the three as a whole It is elastically biased in advance, and with durable wear, the elastic bias will be able to compensate for the meshing gap caused by wear, so as to avoid the steering noise and hairpin feeling caused by the meshing gap.

Description of drawings

With reference to the accompanying drawings, the disclosure of the present utility model will become easier to understand. Those skilled in the art can easily understand that: these drawings are only for the purpose of illustration, and are not intended to limit the protection scope of the present utility model. In addition, like numerals are used to designate like parts in the drawings, wherein:

Fig. 1 is a cross-sectional view of a deceleration mechanism of an electric power steering system according to the present invention;

Fig. 2a and Fig. 2b are respectively the sectional view and the front view of the bearing bush according to the utility model;

Fig. 3a and Fig. 3b are respectively a sectional view and a front view of the bearing bracket according to the present invention.

Specific implementation methods :

It is easy to understand that, according to the technical solution of the present utility model, those skilled in the art can propose various interchangeable structural modes and implementation modes without changing the spirit of the present utility model. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the utility model, and should not be regarded as the whole of the utility model or as a limitation or restriction on the technical solution of the utility model.

The directional terms such as up, down, left, right, front, back, front, back, top, and bottom that are mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings, and they are It is a relative concept, so it may change accordingly according to its different positions and different usage states. Accordingly, these or other directional terms should not be construed as limiting terms.

Referring to Fig. 1, it shows a reduction mechanism of an electric power steering system according to the present invention, the reduction mechanism includes a housing 1, a worm 3 and a worm wheel 2 accommodated in the housing 1 and engaged with each other, in the figure Among them, the worm 3 is basically horizontal, which includes a first end on the left side and a second end on the right side in the figure, the first end of the worm 3 fits in the auxiliary bearing 4, and the auxiliary bearing 4 is then inserted In a bearing bush 5, said bearing bush 5 is fixed in a hole in said housing 1 (for example press-fit fixed), said bearing bush 5 comprises an inner ring 5a engaged with said auxiliary bearing 4 ( Referring to Fig. 2b), the outer ring 5b engaged with the hole in the housing 1 and the elastic connecting rib 5c, the elastic connecting rib 5c connects the inner ring 5a and the outer ring 5b, so that the inner ring 5a can be opposite The outer ring 5b moves radially, the second end of the worm 3 fits in the main bearing 6, and the main bearing 6 is then inserted into the bearing bracket 7, and the bearing bracket 7 includes a The joined main body 7a, the support 7b for fixing to the housing 1 and the washer 7c installed in the main body 7a, the main body 7a and the support 7b are connected by upper and lower elastic connecting ribs (see Figure 3b), the The support member 7b is fixed on the housing 1 by a lock nut 8 .

According to one embodiment of the present utility model, the first end of the worm 3 is in interference fit with the auxiliary bearing 4, and the second end of the worm 3 is in interference fit with the main bearing 6, so that the three are opposite to each other. Fix them together so as to avoid the noise caused by their collision with each other.

According to an embodiment of the present utility model, the auxiliary bearing 4 and the main bearing 6 are both deep groove ball bearings.

According to an embodiment of the present utility model, the bearing bush 5 is press-fitted in the housing 1, and the worm 3, the auxiliary bearing 4, the main bearing 6 and the bearing bracket 7 are fixed as one, And inserted into the bearing bushing 5 together, such a design is convenient for assembly.

As shown in Figure 1, the axis A' of the assembled worm 3 (together with the auxiliary bearing 4, the main bearing 6 and the bearing bracket 7) is slightly angled to the horizontal axis A, due to the Due to the support provided by the sleeve 5 and the bearing bracket 7, the upper and lower elastic connecting ribs connecting the bracket main body 7a of the bearing bracket and the support piece 7b are slightly deformed, and the inner ring 5a of the bearing bush 5 is relatively larger than the outer ring 5b of the bushing. Radial movement allows for such elastic biasing. This elastic bias automatically compensates for the play between the worm gears after long-term wear of the worm gears, thus preventing steering noise and hairpins.

In one embodiment, there is play in the engagement of the auxiliary bearing 4 with the inner ring 5a of the bearing bush 5, making assembly easier.

In one embodiment, there is a gap between the bracket body 7a and the housing 1, thereby allowing the above described worm overall to be biased.

In one embodiment, the support member 7b has a positioning block corresponding to the positioning hole in the housing 1, and/or the bearing bush 5 further has a positioning block 5d. So that the bearing bush 5 and the bearing bracket 7 can be positioned accurately in the circumferential direction.

In one embodiment, the bearing bush 5 is made of elastic material, such as non-metallic material, plastic and so on.

Reference is now made to Figures 2a and 2b, which more clearly illustrate the structure of the bearing bush 5. The bearing bush 5 is generally an elastic component, made of non-metallic material, for example, it can be manufactured integrally by injection molding. The outer ring 5b joined by the hole in 1 and the elastic connecting rib 5c, the elastic connecting rib 5c connects the inner ring 5a and the outer ring 5b, so that the inner ring 5a can be moved relative to the outer ring 5b within a certain range radial movement. The bearing bush 5 also includes positioning blocks 5d for accurate circumferential positioning.

Referring now to Figures 3a and 3b, which more clearly illustrate the construction of a bearing bracket 7 comprising a body 7a engaging said bearing 6 (preferably enclosing the bearing 6 as shown), A support 7b for fixing to the housing 1 and a washer 7c mounted in a main body 7a enclosing the bearing 6 and the washer 7c in one piece. The main body 7 a is connected to the supporting member 7 b through two upper and lower elastic connecting ribs, and the supporting member 7 b is then fixed on the housing 1 through a locking nut 8 . The support member 7b of the shown bearing bracket 7 also includes a positioning block 7d, which matches with a corresponding hole on the housing 1 for accurate circumferential positioning.

According to the utility model, the speed reduction mechanism of the electric power steering system can be assembled as follows, the worm 3, the auxiliary bearing 4, the main bearing 5 and the bearing bracket 7 are preassembled into one body, and the four are matched without gaps to prevent them from colliding with each other. Noise, and then inserted as a whole into the inner ring 5a of the bearing bush 5 that is pre-press fitted to the housing 1, and the auxiliary bearing 4 has a certain gap with the inner ring 5a for installation. Due to the action of the elastic connecting rib 5c, it can make a certain radial movement relative to the outer ring of the bush 5b, thereby absorbing the vibration, thereby avoiding the sound of the auxiliary bearing 4 and the worm 3 colliding with the housing 1 when they move as a whole. Subsequently, the support 7 b is fixed to the housing 1 by means of nuts 8 . After the worm gear is pre-tightened, the above-mentioned whole is inclined at a certain angle relative to the center line of the worm installation cavity of the housing 1, so that the upper and lower connecting ribs of the elastic support 7b are elastically deformed, and under the reaction of the elastic deformation, the worm gear The worm remains snug at all times, automatically compensating for any backlash that may occur due to wear. This structure can set the initial inclination angle of the worm according to the actual needs, avoiding the steering noise and the stuck feeling caused by the meshing gap, and improving the driving comfort.

The specific embodiments described above are only to describe the principle of the present utility model more clearly, and each component is embodied to make the principle of the present utility model easier to understand. Those skilled in the art can easily make various modifications to the present invention without departing from the scope of the present invention. Therefore, it should be understood that the scope of the present invention should not be limited by the above specific examples.

Claims (10)

1. an electric boosting steering system, it comprises speed reduction gearing, it is characterized in that, described speed reduction gearing comprises housing (1), to be contained in described housing (1) and the worm screw be engaged with each other (3) and worm gear (2), described worm screw (3) comprises first end and the second end, the first end of described worm screw (3) is engaged in auxiliary bearing (4), described auxiliary bearing (4) is plugged in bearing lining (5) then, described bearing lining (5) is fixed in the hole in described housing (1), described bearing lining (5) comprises the inner ring (5a) engaged with described auxiliary bearing (4), the outer ring (5b) engaged with the hole in described housing (1) and elasticity dowel (5c), described elasticity dowel (5c) connects described inner ring (5a) and outer ring (5b), make described inner ring (5a) relatively described outer ring (5b) radial motion can be done, second end of described worm screw (3) is engaged in main bearing (6), described main bearing (6) is plugged in bearing support (7) then, described bearing support (7) comprises the main body (7a) that engages with described main bearing (6) and the strut member (7b) for being fixed to housing (1), described main body (7a) is connected by upper and lower elasticity dowel with described strut member (7b), described strut member (7b) is fixed on described housing (1).

2. electric boosting steering system according to claim 1, it is characterized in that, the first end of described worm screw (3) and described auxiliary bearing (4) interference fit, and second end of described worm screw (3) and described main bearing (6) interference fit.

3. electric boosting steering system according to claim 1, is characterized in that, described auxiliary bearing (4) and described main bearing (6) are deep groove ball bearing.

4. electric boosting steering system according to claim 1, is characterized in that, described worm screw (3), described auxiliary bearing (4), and described main bearing (6) and described bearing support (7) are fixed as one.

5. electric boosting steering system according to claim 4, is characterized in that, described auxiliary bearing (4) exists gap with the joint of the inner ring (5a) of described bearing lining (5).

6. electric boosting steering system according to claim 5, is characterized in that, there is gap between described rack body (7a) and described housing (1).

7. electric boosting steering system according to claim 1, is characterized in that, described strut member (7b) has the locating piece corresponding with the knock hole in described housing (1).

8. electric boosting steering system according to claim 1, is characterized in that, described bearing lining (5) also has locating piece (5d).

9. electric boosting steering system according to claim 1, is characterized in that, is provided with packing ring (7c) in described rack body (7a).

10. electric boosting steering system according to claim 1, is characterized in that, described strut member (7b) is fixed on housing (1) by jam nut (8).