An electric power steering mechanism based on a lead screw drive

Abstract

The utility model relates to a kind of electric power steering mechanism based on screw drive, including motor, screw, nut pair and tooth fan;The screw butt joint in the output end of motor, the nut pair is at the outer periphery of screw, the upper portion of the nut pair is equipped with guiding mechanism;The upper surface of the guiding mechanism is provided with tooth slot one, the tooth fan is at the upper position of guiding mechanism, wherein the axis of tooth fan is connected with EPS output shaft.This scheme is by screw, nut pair and slider rigid connection, slider bearing tooth slot one is meshed with tooth fan, avoid the problem that traditional nut pair tooth structure is complex, processing difficulty is big and cost is high, thereby significantly reduce overall manufacturing cost and process complexity.

Description

Technical Field

[0001] This utility model belongs to the field of steering technology, specifically an electric power steering mechanism based on lead screw drive. Background Technology

[0002] Most mainstream steering gears adopt a recirculating ball structure. This structure transmits steering force through helical grooves and recirculating balls on the steering shaft and hydraulic power assist. The recirculating ball steering gear has a mature structure and is widely used.

[0003] However, during the transmission process, there is a certain amount of sliding friction between the balls and the spiral grooves, resulting in low transmission efficiency. At the same time, there are mechanical gaps inside the structure, which affect the sensitivity of steering response and the smoothness of the feel. In addition, the transmission components of the recirculating ball structure are subjected to uneven force, which is prone to wear during long-term use, reducing the reliability and life of the system. Furthermore, directly cutting the grooves on the hollow cylinder (lead screw and nut pair) will significantly weaken the polar inertia and section modulus of the cross section, resulting in a decrease in torque / thrust and fatigue life. If the grooves are cut after heat treatment, they will also destroy the original surface hardened layer and microstructure, introducing residual tensile stress and microcrack sources.

[0004] In view of this, an electric power steering mechanism based on lead screw drive is proposed. Utility Model Content

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the present invention.

[0006] Given the following technical problems in the existing technology: during the transmission process, there is a certain amount of sliding friction between the ball and the spiral groove, resulting in low transmission efficiency. At the same time, there is mechanical clearance inside the structure, which affects the sensitivity of steering response and the smoothness of the feel. In addition, the transmission components of the recirculating ball structure are subjected to uneven force, which is prone to wear during long-term use, reducing the reliability and life of the system. Furthermore, directly cutting the groove on the hollow cylinder (lead screw and nut pair) will significantly weaken the polar inertia and section modulus of the cross section, resulting in a decrease in torque / thrust and fatigue life. If the groove is cut after heat treatment, it will also destroy the original surface hardened layer and microstructure, introducing residual tensile stress and microcrack sources.

[0007] To solve the above-mentioned technical problems, this utility model provides the following technical solution: an electric power steering mechanism based on a lead screw drive, comprising a motor, a lead screw, a nut pair, and a gear sector;

[0008] The lead screw is connected to the output end of the motor, the nut assembly is located on the outer periphery of the lead screw, and a guide mechanism is provided on the upper part of the nut assembly;

[0009] The upper surface of the guide mechanism is provided with a toothed groove, and the toothed sector is located above the guide mechanism, wherein the axis of the toothed sector is connected to the EPS output shaft.

[0010] As a preferred technical solution for an electric power steering mechanism based on a lead screw drive, a planetary reducer is installed between the motor and the lead screw.

[0011] As a preferred technical solution for an electric power steering mechanism based on a lead screw drive, the nut pair has a threaded groove, and the lead screw is threaded into the threaded groove.

[0012] As a preferred technical solution for an electric power steering mechanism based on a lead screw drive, the guiding mechanism includes a slider and a guide rail. The slider is located on the outer periphery of the guide rail, wherein the guide rail is fixedly installed at a designated position, and the slider is located on the upper surface of a nut pair, wherein the nut pair and the slider are integrally formed.

[0013] As a preferred technical solution for an electric power steering mechanism based on a lead screw drive, the slider is provided with a guide groove, which is adapted to and slidably connected to the guide rail.

[0014] As a preferred technical solution for an electric power steering mechanism based on a lead screw drive, the slider is square, and the upper surface of the slider is provided with a toothed groove.

[0015] As a preferred technical solution for an electric power steering mechanism based on a lead screw drive, the protruding part of the gear sector is provided with a second tooth groove, which meshes with the first tooth groove.

[0016] The beneficial effects of this utility model are:

[0017] 1. This solution rigidly connects the lead screw, nut pair, and slider, and the slider carries the tooth groove to achieve meshing with the tooth sector, avoiding the problems of complex tooth structure, high processing difficulty and high cost of traditional nut pair, thus significantly reducing the overall manufacturing cost and process complexity.

[0018] 2. This solution makes the meshing of the gear slot and the gear sector more stable by the linear reciprocating motion of the slider along the guide rail, reducing the backlash and lag in the transmission, improving the rigidity and response speed of the system, and enhancing the precision and handling feel of the power steering.

[0019] 3. In this design, the slider and guide rail share the meshing load, reducing wear on the nut pair, extending the service life of the transmission components, and the structure is easier to maintain and replace, thus improving the overall reliability of the system.

[0020] 4. The simplified transmission structure facilitates integration with existing planetary reducers and motor systems, adapts to various vehicle models and power steering requirements, and enhances the product's versatility and promotional value.

[0021] 5. Compared with the traditional recirculating ball steering system, the present invention reduces the transmission links and ball circulation channels, reduces mechanical inertia, makes the power steering system more responsive, and provides a more comfortable driving experience.

[0022] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objectives and other advantages of this invention can be realized and obtained by means of the structures particularly pointed out in the description and the drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them:

[0024] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0025] Figure 2 This is a schematic diagram on the right side of the present invention.

[0026] Figure label:

[0027] 100. Motor; 101. Lead screw; 102. Planetary reducer; 200. Guide rail; 300. Nut pair; 301. Slider; 302. Gear groove one; 303. Thread groove; 304. Guide groove; 400. Gear sector; 401. Gear groove two. Detailed Implementation

[0028] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single embodiment or an embodiment selectively excluded from other embodiments.

[0031] Secondly, this utility model is described in detail with reference to the schematic diagrams. When describing the embodiments of this utility model, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this utility model. In addition, actual manufacturing should include the three-dimensional spatial dimensions of length, width, and depth.

[0032] Example, refer to Figure 1 and 2 An electric power steering mechanism based on lead screw drive includes a motor 100, a lead screw 101, a nut pair 300, and a gear sector 400.

[0033] The lead screw 101 is connected to the output end of the motor 100, the nut assembly 300 is located on the outer periphery of the lead screw 101, and a guide mechanism is provided on the upper part of the nut assembly 300; a planetary reducer 102 is installed between the motor 100 and the lead screw 101.

[0034] The upper surface of the guide mechanism is provided with a toothed groove 302, and the toothed sector 400 is located above the guide mechanism. The axis of the toothed sector 400 is connected to the EPS output shaft. The nut pair 300 is provided with a threaded groove 303, and the lead screw 101 is threaded into the threaded groove 303.

[0035] The guiding mechanism includes a slider 301 and a guide rail 200. The slider 301 is located on the outer periphery of the guide rail 200, and the guide rail 200 is fixedly installed at a designated position. The slider 301 is located on the upper surface of the nut assembly 300, and the nut assembly 300 and the slider 301 are integrally formed. A guide groove 304 is provided on the slider 301, and the guide groove 304 is adapted to and slidably connected to the guide rail 200. The slider 301 is square, and a toothed groove 302 is provided on the upper surface of the slider 301.

[0036] When the lead screw 101 rotates, it drives the nut assembly 300 to move axially by means of the threaded groove 303. Under the guidance of the guide rail 200 and the guide groove 304, the nut assembly 300 and the slider 301 can move axially.

[0037] The protruding part of the gear sector 400 is provided with a second tooth groove 401, which meshes with the first tooth groove 302.

[0038] This implementation achieves the following: the rotation of motor 100 is transmitted to lead screw 101 via planetary reducer 102. The rotation of lead screw 101 causes nut assembly 300 to reciprocate along the axis. Nut assembly 300 drives slider 301 to reciprocate along guide rail 200. The first tooth groove 302 on slider 301 meshes with the second tooth groove 401 on gear sector 400, converting the reciprocating linear motion into the rotational output of gear sector 400, thus completing the steering assist.

[0039] It should be understood that numerous specific implementation decisions can be made during the development of any actual implementation method, and in any engineering or design project. Such development efforts may be complex and time-consuming, but for those of ordinary skill in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0040] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An electric power steering mechanism based on a lead screw drive, characterized in that: Includes a motor (100), a lead screw (101), a nut assembly (300), and a gear sector (400); The lead screw (101) is connected to the output end of the motor (100), the nut pair (300) is located on the outer periphery of the lead screw (101), and the upper part of the nut pair (300) is provided with a guide mechanism; The upper surface of the guide mechanism is provided with a toothed groove (302), and the toothed sector (400) is located above the guide mechanism.

2. The electric power steering mechanism based on a lead screw drive according to claim 1, characterized in that: A planetary reducer (102) is installed between the motor (100) and the lead screw (101).

3. The electric power steering mechanism based on a lead screw drive according to claim 1, characterized in that: The nut assembly (300) has a threaded groove (303), and the lead screw (101) is threaded into the threaded groove (303).

4. The electric power steering mechanism based on a lead screw drive according to claim 1, characterized in that: The guiding mechanism includes a slider (301) and a guide rail (200). The slider (301) is located on the outer periphery of the guide rail (200), wherein the guide rail (200) is fixedly installed at a designated position. The slider (301) is located on the upper surface of the nut pair (300), and the nut pair (300) and the slider (301) are integrally formed.

5. The electric power steering mechanism based on a lead screw drive according to claim 4, characterized in that: The slider (301) is provided with a guide groove (304), which is adapted to and slidably connected to the guide rail (200).

6. The electric power steering mechanism based on a lead screw drive according to claim 4, characterized in that: The slider (301) is square, and a toothed groove (302) is provided on the upper surface of the slider (301).

7. The electric power steering mechanism based on a lead screw drive according to claim 1, characterized in that: The protruding part of the toothed sector (400) is provided with a second toothed groove (401), which meshes with a first toothed groove (302).

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