CN112061230A

CN112061230A - Electric power steering apparatus and torque transmission apparatus thereof

Info

Publication number: CN112061230A
Application number: CN202011009558.8A
Authority: CN
Inventors: 朱兴旺; 朱胜峰; 万民伟; 朱忠明; 任培; 黄亮亮
Original assignee: Hangzhou Shibao Auto Steering Gear Co ltd
Current assignee: Hangzhou Shibao Auto Steering Gear Co ltd
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2020-12-11

Abstract

The invention discloses an electric power steering device and a torque transmission device thereof, and relates to the technical field of power transmission. One end of the worm wheel is matched with the first bearing, and the other end of the worm wheel is abutted against a shaft shoulder of the screw section connected with the first smooth section, so that the worm wheel is fixed between the first bearing and the screw section, and when the worm wheel is meshed with the worm, the worm wheel is not easy to slip and has larger transmission torque; the worm wheel is arranged at one end, close to the screw rod section, of the first bearing, and when the worm wheel is meshed with the worm, the matching distance between the worm wheel and the worm is reduced, so that the structure of the torque transmission device is more compact, and the installation area is reduced.

Description

Electric power steering apparatus and torque transmission apparatus thereof

Technical Field

The invention relates to the technical field of power transmission, in particular to an electric power steering device and a torque transmission device thereof.

Background

The electric steering device of the circulating ball is characterized in that a motor drives a steering screw nut to move up and down through a speed reducing mechanism, and the steering screw nut is converted into an output shaft to rotate, so that the purpose of steering is fulfilled. The electric steering gear of the recirculating ball is characterized in that the worm wheel is arranged on the outer sides of the bearing and the end cover, one end of the worm wheel is abutted to the end cover, the other end of the worm wheel has no acting point, the center distance of the worm wheel is easy to change after the worm wheel is stressed, and when the worm wheel is matched with the worm, the worm wheel is easy to slip, so that the driving safety is influenced.

Disclosure of Invention

1. Technical problem to be solved by the invention

Aiming at the technical problem that a worm wheel is matched with a worm and is easy to slip, the invention provides an electric power steering device and a torque transmission device thereof.

2. Technical scheme

In order to solve the problems, the technical scheme provided by the invention is as follows: the utility model provides a torque transmission device, includes lead screw, first bearing and worm wheel, the lead screw includes the screw rod section and locates the first smooth section of screw rod section one end, the cover is equipped with first bearing and worm wheel on the first smooth section, the one end and the first bearing cooperation of worm wheel, the other end of worm wheel supports and leans on the shaft shoulder department that is connected at screw rod section and first smooth section.

One end of the worm wheel is matched with the first bearing, and the other end of the worm wheel is abutted against a shaft shoulder of the screw section connected with the first smooth section, so that the worm wheel is fixed between the first bearing and the screw section, and when the worm wheel is meshed with the worm, the worm wheel is not easy to slip and has larger transmission torque; the worm wheel is arranged at one end, close to the screw rod section, of the first bearing, and when the worm wheel is meshed with the worm, the matching distance between the worm wheel and the worm is reduced, so that the structure of the torque transmission device is more compact, and the installation area is reduced.

Optionally, the worm wheel includes a body and a tooth portion coaxially disposed on the outer periphery of the body, the tooth portion protrudes from the side surface of the body, so that the tooth portion and the side surface of the body form a groove, the tooth portion is engaged with the worm, the first bearing includes an inner ring and an outer ring, the inner ring protrudes outwards to form an annular raceway, the raceway is used for mounting balls, and the inner ring is matched with the body.

Optionally, the worm gear is made of metal.

Optionally, the screw section is coaxially sleeved with a steering nut, and the steering nut is used for being meshed with the output shaft.

Optionally, the lubricating medium of the worm gear is gear oil.

Optionally, the first smooth section is still overlapped and is equipped with the end cover, the end cover is located the one end that the worm wheel was kept away from to first bearing, be equipped with on the end cover with first bearing cooperation ground mounting groove, the mounting groove bottom is equipped with the annular face, first bearing assembly is in the mounting groove, and the outer lane of first bearing offsets with the annular face of mounting groove bottom.

Optionally, one end of the screw section, which is far away from the first smooth section, is provided with a second smooth section, the second smooth section is sleeved with a second bearing, and the first bearing and the second bearing are used for bearing an axial force.

Optionally, a steel ball is arranged between the steering nut and the screw rod, and the steel ball rolls in a ball groove formed by the screw rod and the steering nut.

Optionally, the screw section, the first smooth section and the second smooth section are of an integrally formed structure.

The invention also discloses an electric power steering device which comprises a shell, a worm matched with the worm wheel, a motor connected with the worm and the torque transmission device, wherein the torque transmission device, the worm and the motor are all positioned in the shell.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

(1) the torque transmission device that this application embodiment provided, the one end and the first bearing cooperation of worm wheel, the other end support and lean on the shaft shoulder department that is connected at screw rod section and first smooth section, make the worm wheel fix between first bearing and screw rod section, when worm wheel and worm meshing, the worm wheel is difficult to skid, has bigger transmission moment of torsion.

(2) The torque transmission device that this application embodiment provided, the worm wheel setting is in the one end that first bearing is close to the screw rod section, and when worm wheel and worm meshing, reduced the cooperation distance between worm wheel and the worm, make torque transmission device structure compacter, reduce the installation area.

Drawings

FIG. 1 is a schematic structural diagram of a torque transmitting device according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a worm gear of the torque transmission device according to an embodiment of the present invention;

FIG. 3 is a schematic structural view of a torque transmission end cap according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an electric power steering apparatus according to an embodiment of the present invention.

Detailed Description

For a further understanding of the present invention, reference will now be made in detail to the embodiments illustrated in the drawings.

The present application will be described in further detail with reference to the following drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not restrictive of the invention. It should be noted that, for convenience of description, only the portions related to the present invention are shown in the drawings. The terms first, second, and the like in the present invention are provided for convenience of describing the technical solution of the present invention, and have no specific limiting effect, but are all generic terms, and do not limit the technical solution of the present invention. It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. The technical solutions in the same embodiment and the technical solutions in different embodiments can be arranged and combined to form a new technical solution without contradiction or conflict, and the technical solutions are within the scope of the present invention.

Example 1

With reference to fig. 1-4, the torque transmission device of the present embodiment includes a lead screw 1, a first bearing 2 and a worm wheel 3, the lead screw 1 includes a screw section 11 and a first smooth section 12 disposed at one end of the screw section 11, the first bearing 2 and the worm wheel 3 are sleeved on the first smooth section 12, one end of the worm wheel 3 is matched with the first bearing 2, and the other end of the worm wheel 3 abuts against a shoulder of the screw section 11 connected with the first smooth section 12. The steering wheel is connected with the input shaft, a torque sensor on the input shaft transmits force applied to the steering wheel to the motor 8, the motor 8 applies force to the worm 9, the worm 9 drives the worm wheel 3 to rotate, the worm wheel 3 transmits steering force to the screw rod 1 and the steering nut 14, and the steering nut 14 drives the output shaft 4 assembly to move repeatedly to complete the power assisting function. One end of the worm wheel 3 is matched with the first bearing 2, and the other end of the worm wheel 3 is abutted against a shaft shoulder of the screw section 11 connected with the first smooth section 12, so that the worm wheel 3 is fixed between the first bearing 2 and the screw section 11, when the worm wheel 3 is meshed with the worm 9, the worm wheel 3 is not easy to slip and has larger transmission torque; the worm wheel 3 is arranged at one end, close to the screw section 11, of the first bearing 2, and when the worm wheel 3 is meshed with the worm 9, the matching distance between the worm wheel 3 and the worm 9 is reduced, so that the structure of the torque transmission device is more compact, and the installation area is reduced.

Example 2

With reference to fig. 1-4, the torque transmission device of the present embodiment can be improved as follows compared with the technical solution of embodiment 1: the worm wheel 3 comprises a body 31 and a tooth part 32 coaxially arranged on the periphery of the body 31, the tooth part 32 protrudes relative to the side surface of the body 31, so that the tooth part 32 and the side surface of the body 31 form a groove, the tooth part 32 is meshed with the worm 9, the first bearing 2 comprises an inner ring 21 and an outer ring 22, the inner ring 21 protrudes outwards to form an annular raceway, the raceway is used for installing balls, and the inner ring 21 is matched with the body 31. The inner ring 21 of the first bearing 2 is matched with the worm wheel 3 body 31, so that the connection between the first bearing 2 and the worm wheel 3 is more compact, and the worm wheel 3 is more stable.

Example 3

With reference to fig. 1-4, the torque transmission device of the present embodiment can be improved as follows compared with the solution of embodiment 1 or 2: the worm wheel 3 is made of metal. The metal material can greatly improve the mechanical strength of the worm wheel 3 and meet the requirement of a large-torque transmission device.

Example 4

With reference to fig. 1-4, the torque transmission device of the present embodiment can be modified as follows, compared with any of embodiments 1-3: the screw section 11 is coaxially sleeved with a steering nut 14, and the steering nut 14 is used for being meshed with the output shaft 4. The worm wheel 3 drives the screw rod 1 to rotate, the screw rod 1 drives the steering nut 14 to axially move, and the steering nut 14 enables the output shaft 4 to rotate to finish steering.

Example 5

With reference to fig. 1-4, the torque transmission device of the present embodiment can be modified as follows, compared with any of embodiments 1-4: the lubricating medium of the worm wheel 3 is gear oil. The gear oil can greatly reduce the noise generated by the matching of the worm wheel 3 and the worm 9, the worm wheel 3 is arranged at one end, close to the screw rod section 11, of the first bearing 2, when the gear oil is used, the worm wheel 3 and the steering nut 14 can be simultaneously lubricated, and the gear oil can also effectively reduce the heat generated by the meshing rotation between the worm wheel 3 and the worm 9 and between the steering nut 14 and the screw rod 1.

Example 6

With reference to fig. 1-4, the torque transmission device of the present embodiment can be modified as follows, compared with any of embodiments 1-5: first smooth section 12 still overlaps and is equipped with end cover 5, end cover 5 is located first bearing 2 and keeps away from the one end of worm wheel 3, be equipped with on end cover 5 with first bearing 2 cooperation ground mounting groove 51, the mounting groove 51 bottom is equipped with annular surface 52, first bearing 2 assembles in mounting groove 51, and the outer lane 22 of first bearing 2 offsets with the annular surface 52 of mounting groove 51 bottom. The annular surface 52 of the first bearing 2 mounting groove 51 on the end cover 5 is abutted against the outer ring 22 of the first bearing 2, so that the first bearing 2 is stably and axially positioned on the end cover 5, the first bearing 2 is not easy to axially move, and the reliability of the performance of the speed reducing motor of the worm wheel 3 and the worm 9 is ensured.

Example 7

With reference to fig. 1-4, the torque transmission device of the present embodiment can be modified as follows, compared with any of embodiments 1-6: and a second smooth section 13 is arranged at one end, far away from the first smooth section 12, of the screw section 11, a second bearing 6 is sleeved on the second smooth section 13, and the first bearing 2 and the second bearing 6 are used for bearing axial force. The worm wheel 3 is arranged between the first bearing 2 and the second bearing 6, so that the bearing capacity of the worm wheel 3 is increased, and the worm wheel 3 has better rigidity.

Example 8

With reference to fig. 1-4, the torque transmission device of the present embodiment can be modified as follows, compared with any of embodiments 1-7: a steel ball 16 is arranged between the steering nut 14 and the screw rod 1, and the steel ball 16 rolls in a ball groove 15 formed by the screw rod 1 and the steering nut 14. When the screw rod 1 and the steering nut 14 move relatively, the steel balls 16 roll in the ball grooves 15 in a circulating mode, so that sliding friction is changed into rolling friction, and transmission efficiency is improved.

Example 9

With reference to fig. 1-4, the torque transmission device of the present embodiment can be modified as follows, compared with any of embodiments 1-8: the screw section 11, the first smooth section 12 and the second smooth section 13 are of an integrally formed structure. The integrally formed structure enables the screw rod 1 to be a whole without any connection, and has stronger bearing capacity.

Example 10

With reference to fig. 1 to 4, the electric power steering apparatus of the present embodiment includes a housing 7, a worm 9 engaged with the worm wheel 3, a motor 8 connected to the worm 9, and the torque transmission apparatus according to any one of the technical solutions of embodiments 1 to 9, where the torque transmission apparatus, the worm 9, and the motor 8 are all located inside the housing 7. The worm wheel 3 is sleeved on the screw rod 1, the motor 8 drives the worm wheel 3 to rotate through the worm 9, the worm wheel 3 rotates to drive the screw rod 1 to rotate, the screw rod 1 drives the steering nut 14 to axially move, the steering nut 14 enables the output shaft 4 to rotate to finish steering, and the worm 9 is arranged between the first bearing 2 and the screw rod section 11, so that the shell 7 is compact in structure, and the occupied space is greatly reduced. Steering nut 14 overcoat has steering rack 17, have first gap 171 between casing 7 and the steering rack 17 in the rotation process, have second gap 141 between steering nut 14 and the steering rack 17, and the width of first gap 171 is less than the width of second gap 141, make steering rack contact with casing 7 earlier, casing 7 provides reverse effort for steering rack 17, this effort offsets with radial force, steering nut 14 has been avoided receiving the effect of radial force, and then lead screw 1 has been avoided taking place to warp because of receiving the influence of radial force.

The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching, without departing from the spirit of the invention, the person skilled in the art shall not inventively design the similar structural modes and embodiments to the technical solution, but shall fall within the scope of the invention.

Claims

1. The utility model provides a torque transmission device, its characterized in that, includes lead screw, first bearing and worm wheel, the lead screw includes the screw section and locates the first smooth section of screw section one end, the cover is equipped with first bearing and worm wheel on the first smooth section, the one end and the first bearing cooperation of worm wheel, the other end of worm wheel supports and leans on the shaft shoulder department that is connected at screw section and first smooth section.

2. The torque transmission device of claim 1, wherein the worm gear includes a body and teeth coaxially disposed on an outer periphery of the body, the teeth projecting relative to sides of the body such that the teeth form grooves with the sides of the body, the teeth engaging the worm, the first bearing including an inner race and an outer race, the inner race projecting outwardly to form an annular raceway for receiving balls, the inner race engaging the body.

3. The torque transmission device of claim 2, wherein the worm gear is metal.

4. The torque transmission device according to claim 1, wherein the screw section is coaxially sleeved with a steering nut for engaging with the output shaft.

5. The torque transmitting device of claim 5, wherein the lubrication medium of the worm gear is gear oil.

6. The torque transmission device according to claim 1, wherein the first smooth section is further sleeved with an end cover, the end cover is located at an end of the first bearing far away from the worm wheel, the end cover is provided with a mounting groove matched with the first bearing, the bottom of the mounting groove is provided with an annular surface, the first bearing is mounted in the mounting groove, and an outer ring of the first bearing abuts against the annular surface at the bottom of the mounting groove.

7. The torque transmission device according to claim 1, wherein a second smooth section is arranged at an end of the screw section away from the first smooth section, a second bearing is sleeved on the second smooth section, and the first bearing and the second bearing are used for bearing axial force.

8. The torque transmission device according to claim 1, wherein a steel ball is provided between the steering nut and the lead screw, and the steel ball rolls in a ball groove formed between the lead screw and the steering nut.

9. The torque transmission device of claim 1, wherein the screw section, first smooth section, and second smooth section are of unitary construction.

10. An electric power steering device, comprising a housing, a worm engaged with a worm wheel, a motor connected to the worm, and the torque transmission device of claims 1 to 9, wherein the torque transmission device, the worm and the motor are all located inside the housing.