CN219029536U - Electric power steering mechanism - Google Patents

Abstract

The utility model provides an electric power steering mechanism, which comprises a first bearing, a shell with a first bearing hole, a worm wheel and a coupler, wherein the first bearing is positioned in the first bearing hole, is in interference fit with the first bearing hole, and is arranged around the worm in a surrounding manner so as to be used for supporting the worm; the coupling is coupled to the external motor and to a first end of the worm for transmitting torque generated by the external motor to the worm, the worm engaging the worm gear for driving the worm gear in motion. The electric power steering mechanism can simplify the fixed structure of the bearing, has large bearing capacity, small strength weakening of the bearing and the bearing hole and good impact resistance.

Description

Electric power steering mechanism

Technical Field

Embodiments of the present utility model relate to an electric power steering mechanism.

Background

An electric power steering system (Electric Power Steering, abbreviated as EPS) is a power steering system that directly relies on an electric motor to provide assist torque, and has many advantages over conventional hydraulic power steering systems, and thus has been increasingly used. The electric power steering system mainly comprises a torque sensor, a vehicle speed sensor, an electric motor, a speed reducing mechanism, an electronic control unit and the like, wherein the speed reducing mechanism comprises a worm gear mechanism, and the worm needs to be supported through at least one bearing. EPS includes a column electric power steering system (Column Electric Power Steering, abbreviated as C-EPS) in which a power assist motor directly applies power assist to a steering column. Current C-EPS generally use large nuts or snap rings to secure the bearings to the motor end, and the structure is complex and the bearings are subject to wear.

In view of this, the present utility model provides an electric power steering mechanism.

It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the utility model and thus may include information that does not form the prior art that is already known to those of ordinary skill in the art.

Disclosure of Invention

The utility model aims to provide an electric power steering mechanism, which avoids complex connection modes such as nuts, clamping rings and the like by interference fit of a first bearing for supporting a worm and a first bearing hole of a shell.

At least one embodiment of the utility model provides an electric power steering mechanism, which comprises a first bearing, a shell with a first bearing hole, a worm wheel and a coupler, wherein the first bearing is positioned in the first bearing hole, is in interference fit with the first bearing hole, and is arranged around the worm in a surrounding manner so as to be used for supporting the worm; the coupling is coupled to the external motor and to a first end of the worm for transmitting torque generated by the external motor to the worm, the worm engaging the worm gear for driving the worm gear in motion.

For example, in an electric power steering mechanism provided by at least one embodiment of the present utility model, the inner diameter of the first bearing hole is smaller than the outer diameter of the first bearing.

For example, in an electric power steering mechanism provided by at least one embodiment of the present utility model, the outer diameter of the first bearing ranges between 23.991mm and 24.000 mm.

For example, in an electric power steering mechanism provided by at least one embodiment of the present utility model, the first bearing bore has an inner diameter in the range of 23.975mm to 23.990 mm.

For example, in an electric power steering mechanism provided by at least one embodiment of the present utility model, the worm includes a helical tooth portion that mates with the worm wheel, and the first bearing is enclosed at a position between the helical tooth portion and the first end of the worm.

For example, in an electric power steering mechanism provided in at least one embodiment of the present utility model, a worm, a first bearing, and a coupling are coaxially disposed.

For example, in an electric power steering mechanism provided in at least one embodiment of the present utility model, a surface of the worm is provided with a first stopper, and the first stopper is located on a side of the first bearing facing away from the coupling.

For example, in an electric power steering mechanism provided by at least one embodiment of the present utility model, the worm is at least partially located inside the housing.

For example, at least one embodiment of the present utility model provides an electric power steering mechanism further comprising a second bearing and a snap ring, the housing further having a second bearing aperture, the second bearing being positioned in the second bearing aperture and surrounding the second end of the worm, the snap ring being positioned on a side of the second bearing facing away from the first end of the worm.

For example, in the electric power steering mechanism provided in at least one embodiment of the present utility model, the surface of the worm is further provided with a second stopper, and the second stopper is located on a side of the second bearing toward the first end of the worm.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the utility model as claimed.

The electric power steering mechanism has the following beneficial effects:

according to the electric power steering mechanism, the first bearing is in interference fit with the first bearing hole, so that the fixing structure of the bearing can be simplified, the bearing capacity is high, the strength of the bearing and the bearing hole is reduced, and the impact resistance is good.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model. It is evident that the drawings in the following description are only some embodiments of the present utility model and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

FIG. 1 is a cross-sectional view of a housing of an electric power steering mechanism according to at least one embodiment of the present utility model;

FIG. 2 is a partial schematic view of a cross-sectional view of a housing of the electric power steering mechanism shown in FIG. 1;

fig. 3 is a partial cross-sectional view of an electric power steering mechanism provided in at least one embodiment of the present utility model.

Reference numerals

101. First bearing hole

102. Shell body

201. First bearing hole

301. First bearing

302. Shell body

303. Worm screw

304. Worm wheel

305. Coupling device

306. First limiting piece

307. Second bearing

308. Clasp ring

309. Second limiting piece

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present utility model more clear, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. It will be apparent that the described embodiments are some, but not all, embodiments of the utility model. All other embodiments, which can be made by a person skilled in the art without creative efforts, based on the described embodiments of the present utility model fall within the protection scope of the present utility model.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model belongs. The terms "first," "second," and the like, as used herein, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. Likewise, the terms "a," "an," or "the" and similar terms do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprising" or "comprises", and the like, means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof, but does not exclude other elements or items. The terms "connected" or "connected," and the like, are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate relative positional relationships, which may also be changed when the absolute position of the object to be described is changed.

In order to solve the technical problems, the utility model provides a novel electric power steering mechanism, which can simplify the fixing structure of a bearing by interference fit of a first bearing for supporting a worm and a first bearing hole of a shell, has high bearing capacity, small strength weakening of the bearing and the bearing hole and good impact resistance.

Embodiments of the present utility model will be described in detail below with reference to the accompanying drawings, but the present utility model is not limited to these specific embodiments.

Fig. 1 is a cross-sectional view of a housing of an electric power steering mechanism according to at least one embodiment of the present utility model.

As shown in fig. 1, the electric power steering mechanism includes a housing 102, and the housing 102 includes a first bearing hole 101. The thickened frame portion shown in fig. 1 can realize the connection between the first bearing (not shown in fig. 1) and the first bearing hole 101, and the electric power steering mechanism provided by the utility model has a simple structure, unlike the connection by a nut or a snap ring in the prior art.

For example, in the process of manufacturing the electric power steering mechanism provided by the utility model, the first bearing is pressed into the first bearing hole 101 of the housing 102, so that interference fit between the first bearing and the first bearing hole 101 is realized, and the first bearing hole 101 can be fastened together without nuts or snap rings.

Fig. 2 is a partial schematic view of a cross-sectional view of a housing of the electric power steering mechanism shown in fig. 1. Fig. 2 is a schematic view of an interference fit portion of a bearing and a bearing hole.

As shown in fig. 2, in the present utility model, a first bearing (not shown in fig. 2) is located in the first bearing hole 201 and is interference-fitted with the first bearing hole 201.

For example, in some embodiments of the utility model, the inner diameter of the first bearing bore is smaller than the outer diameter of the first bearing.

For example, in some embodiments of the utility model, the outer diameter of the first bearing ranges between 23.991mm and 24.000 mm.

For example, in some embodiments of the utility model, the inner diameter of the first bearing bore ranges between 23.975mm and 23.990mm, the inner diameter of the first bearing bore 201 being shown in fig. 2.

The outer diameter range of the first bearing and the inner diameter range of the first bearing hole are only examples, and the outer diameter of the first bearing and the inner diameter of the first bearing hole may be sized according to actual conditions, as long as the interference fit can be satisfied.

Because the inner diameter of the first bearing hole is smaller than the outer diameter of the first bearing, the elastic pressure is generated between the surfaces of the first bearing hole and the first bearing hole after the first bearing hole is assembled by the interference value of the first bearing and the first bearing hole, so that the fastening connection is obtained. For example, a special tool is used to press the first bearing into the first bearing hole. For example, the first bearing hole is heated to expand the aperture and sleeved on the bearing by utilizing the characteristic of thermal expansion and contraction, and the first bearing hole are fastened together after cooling and contraction.

For example, in some embodiments of the utility model, the pressure applied to press the first bearing into the first bearing bore during installation of the first bearing ranges from 1000N to 2500N.

For example, in some embodiments of the utility model, the pressure of the first bearing bore against the first bearing after assembly is complete ranges between 3000N and 3500N.

Fig. 3 is a partial cross-sectional view of an electric power steering mechanism 300 in accordance with at least one embodiment of the present utility model.

As shown in fig. 3, the electric power steering mechanism includes a first bearing 301, a housing 302 having a first bearing hole, a worm 303, a worm wheel 304, and a coupling 305. The first bearing 301 is located in and interference fit with a first bearing bore (indicated by solid double arrow in fig. 3) and is not coupled by a nut or snap ring as in the prior art. The first bearing 301 is disposed around the worm 303 to support the worm 303, reduce a friction coefficient during movement of the worm 303, and ensure rotation accuracy. Both ends of the coupling 305 are coupled with an external motor (not shown) and a first end of the worm 303, respectively, for transmitting torque generated by the external motor to the worm 303. The worm 303 is engaged with the worm wheel 304 for driving the worm wheel 304 to move. The worm 303 includes a helical tooth portion that mates with the worm wheel 304, and the first bearing 301 is enclosed at a position between the helical tooth portion and the first end of the worm 303. The worm 303, the first bearing 301 and the coupling are coaxially arranged. The surface of the worm 303 is provided with a first stop 306, the first stop 306 being located on the side of the first bearing 301 facing away from the coupling 305. The worm 303 is at least partially located inside the housing 302.

For example, in manufacturing the electric power steering mechanism 300, the first bearing 301 is pressed into the first bearing hole, and then the worm 303 is mounted to cooperate with the worm wheel 304.

For example, in this embodiment, the electric power steering mechanism 300 further includes a second bearing 307 and a snap ring 308, the housing 302 is further provided with a second bearing hole (indicated by a dashed double arrow in fig. 3), the second bearing 307 is located in the second bearing hole and is circumferentially located around the second end of the worm 303, and the snap ring 308 is located on a side of the second bearing 307 facing away from the first end of the worm 303.

For example, in this embodiment, the inner diameter of the second bearing hole is greater than the outer diameter of the second bearing 307.

In this embodiment, the first bearing needs to transmit a larger torque, so that the first bearing is in interference fit with the first bearing hole, the second bearing is connected by using a universal snap ring, and the connection mode of the second bearing is not limited in the utility model.

For example, in this embodiment, the surface of the worm 303 is further provided with a second stop 309, the second stop 309 being located on the side of the second bearing 307 facing the first end of the worm 303.

In summary, the electric power steering mechanism provided by the utility model can simplify the fixing structure of the bearing, has large bearing capacity, small strength weakening of the bearing and the bearing hole and good impact resistance.

The foregoing is a further detailed description of the utility model in connection with the preferred embodiments, and it is not intended that the utility model be limited to the specific embodiments described. It will be apparent to those skilled in the art that several simple deductions or substitutions may be made without departing from the spirit of the utility model, and these should be considered to be within the scope of the utility model.

Claims (10)

1. An electric power steering mechanism is characterized by comprising a first bearing, a shell with a first bearing hole, a worm wheel and a coupler, wherein,

the first bearing is positioned in the first bearing hole, is in interference fit with the first bearing hole, and is arranged around the worm in a surrounding manner so as to be used for supporting the worm;

the coupling is coupled with an external motor and a first end of the worm for transmitting torque generated by the external motor to the worm;

the worm is meshed with the worm wheel for driving the worm wheel to move.

2. The electric power steering mechanism of claim 1, wherein an inner diameter of the first bearing bore is smaller than an outer diameter of the first bearing.

3. An electric power steering mechanism according to claim 2, wherein the first bearing has an outer diameter in the range 23.991mm to 24.000 mm.

4. An electric power steering mechanism according to claim 2, wherein the first bearing bore has an inner diameter in the range 23.975mm to 23.990 mm.

5. The electric power steering mechanism of claim 1, wherein the worm includes a helical tooth portion that mates with the worm wheel, the first bearing being enclosed at a location between the helical tooth portion and the first end of the worm.

6. An electric power steering mechanism according to claim 5, wherein the worm, the first bearing and the coupling are coaxially arranged.

7. An electric power steering mechanism according to claim 5, wherein the surface of the worm is provided with a first stop member, the first stop member being located on a side of the first bearing facing away from the coupling.

8. An electric power steering mechanism according to claim 1, wherein the worm is at least partially located inside the housing.

9. The electric power steering mechanism of claim 1, further comprising a second bearing and a snap ring, the housing further having a second bearing aperture, the second bearing being positioned in the second bearing aperture and surrounding the second end of the worm, the snap ring being positioned on a side of the second bearing facing away from the first end of the worm.

10. The electric power steering mechanism of claim 9, wherein the surface of the worm is further provided with a second stop, the second stop being located on a side of the second bearing facing the first end of the worm.

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