Prevent rubber body from falling out configuration nut pre-tightening structure and electric power steering system

Abstract

The utility model discloses a kind of prevent rubber body from being configured nut pre-tightening structure that comes out, including nut body, rubber body and wave spring;The head of the rubber body is fixedly connected by embedding corresponding groove of nut body with its outer peripheral protrusion;The wave spring is arranged between the tail of the rubber body and nut body;The inner hole diameter of the wave spring is greater than the head outer diameter of rubber body, less than the tail outer diameter of rubber body.The configured nut pre-tightening structure of the utility model is reliable and prevents from coming out, eliminates noise source;Glue-free environmental protection, improve cleanliness;Enhance pre-tightening, performance is more optimal.

Description

Technical Field

[0001] This utility model relates to a pre-tightening nut structure for preventing rubber body from coming off, and an electric power steering system using this pre-tightening nut structure. Background Technology

[0002] In electric power steering systems, the nut serves as a crucial connecting component between the steering gear servo housing and the support bearing, undertaking functions of fixing, adjustment, and cushioning. For ease of explanation, its structure can be divided into two parts:

[0003] The configuration nut subassembly consists of a configuration nut body and a configuration nut rubber body. In the servo housing subassembly, the worm and worm wheel within the bracket bearing initially have a clearance fit. By tightening the configuration nut body, the thread engagement depth can be changed, precisely adjusting the meshing tightness between the worm wheel and worm, thus meeting specific customer requirements for the meshing state (excessive loose meshing easily generates noise, while excessive tight meshing accelerates worm wheel and worm wear, affecting lifespan).

[0004] like Figure 3 As shown, in the current configuration of the nut sub-assembly, the rubber body is fixed to the main body by adhesive. This process has a significant defect:

[0005] 1. Risk of rubber body detachment: Improper control of rubber quantity (insufficient or aged rubber) can easily cause the rubber body to detach from the main body. The detached rubber body cannot provide the preload required by the design. After the vehicle has undergone fatigue and vibration endurance conditions, the nuts may loosen, which may lead to noise problems.

[0006] 2. Cleanliness issues: Increasing the amount of adhesive to prevent detachment can easily lead to adhesive overflow. Overflowing adhesive, once cured, poses a risk of detachment, contaminating the system and severely impacting product cleanliness.

[0007] 3. The existing structure of the nut configuration relies solely on the rubber body to provide the initial preload. As the rack force required by the steering gear increases, this single source of preload is becoming insufficient. Utility Model Content

[0008] To solve the above-mentioned technical problems, this utility model provides a pre-tightening structure for a nut to prevent the rubber body from coming off, including a nut body, a rubber body, and a wave spring; the head of the rubber body is fixedly connected by its outer peripheral protrusion being embedded in the corresponding groove of the nut body; the wave spring is disposed between the tail of the rubber body and the nut body; the inner diameter of the wave spring is larger than the outer diameter of the head of the rubber body and smaller than the outer diameter of the tail of the rubber body.

[0009] Preferably, the outer end face of the tail of the rubber body is higher than the outer end face of the wave spring.

[0010] Preferably, the outer peripheral protrusion of the head of the rubber body has a trapezoidal cross section.

[0011] Preferably, the outer peripheral protrusion of the head of the rubber body has a semi-circular cross section.

[0012] Preferably, the stiffness coefficient of the wave spring is greater than the stiffness coefficient of the rubber body.

[0013] This utility model also provides an electric power steering system, including the aforementioned pre-tightening structure for preventing rubber body dislodgement, wherein the pre-tightening nut is disposed on the housing of the electric power steering system and is used to adjust the meshing tightness of the worm gear and worm of the electric power steering system. Attached Figure Description

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0015] Figure 1 This is a schematic diagram of the pre-tightening nut structure for preventing the rubber body from coming off in Example 1;

[0016] Figure 2 This is a schematic diagram of the electric power steering system structure in Example 2;

[0017] Figure 3 This is a schematic diagram of a structure with a nut configured in the background art. Detailed Implementation

[0018] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can fully understand the other advantages and technical effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. The following exemplary embodiments of this utility model can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of this utility model thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art.

[0019] Example 1

[0020] like Figure 1As shown, this embodiment provides a pre-tightening nut structure to prevent the rubber body from coming off, including a nut body 1, a rubber body 2, and a wave spring 3; the head 21 of the rubber body is fixedly connected by its outer peripheral protrusion being embedded into the corresponding groove of the nut body 1; the wave spring 3 is disposed between the tail 22 of the rubber body and the nut body 1; the inner diameter of the wave spring 3 is larger than the outer diameter of the head 21 of the rubber body and smaller than the outer diameter of the tail 22 of the rubber body.

[0021] The outer end face of the tail portion 22 of the rubber body is higher than the outer end face of the wave spring 3. The outer peripheral protrusion cross-section of the head portion 21 of the rubber body is trapezoidal in this embodiment, but it can also be semi-circular or other shapes.

[0022] The cross-section of the tail portion 22 of the rubber body is trapezoidal in this embodiment, but it can also be semi-circular or other shapes.

[0023] Preferably, the stiffness coefficient of the wave spring is greater than that of the rubber body. The rubber body provides initial flexible preload, while the wave spring provides subsequent rigid support, significantly improving the reliability and durability of the preload force.

[0024] When installing the nut, the wave spring 3 is first inserted into the rubber body 2, and then the rubber body 2 is fixed to the nut body 1 by pressure. The head 21 of the rubber body forms a mechanical interlock (the head of the rubber body undergoes elastic deformation during assembly, passes through the inlet, and after reset, the straight edge fills the groove to form an irreversible interlock), thereby ensuring that the rubber body 2 does not come out, and the wave spring is fixed by the structure of the tail 22 of the rubber body.

[0025] Compared with the prior art, the configuration of the nut preload structure in this embodiment has the following technical advantages:

[0026] 1. By optimizing the structure of the assembly area between the nut body and the rubber body (such as improving the geometric configuration), the risk of the rubber body coming off during use is eliminated. This design abandons the traditional glue fixing process, ensuring reliable fixing of the rubber body while also reducing manufacturing costs (eliminating the glue application process / glue cost) and ensuring product cleanliness (avoiding glue overflow and contamination);

[0027] 2. Improved preload performance of the mounting nut: By adding a wave spring, a secondary preload force is provided to the mounting nut. This design effectively solves the problem of insufficient preload force relying solely on the rubber body, thereby completely avoiding the risk of the mounting nut loosening and generating noise due to insufficient preload force.

[0028] Example 2

[0029] like Figure 2 As shown, this embodiment provides an electric power steering system, including a housing 5, a bracket bearing 6, a worm gear 7, a worm 8, and a nut 9 as described in Embodiment 1.

[0030] The configuration nut 9 is mounted on the housing 5 of the electric power steering system and is used to adjust the meshing tightness between the worm gear 7 and the worm 8 of the electric power steering system. Specifically, during assembly and tightening, the rubber body of the configuration nut 9 first contacts and compresses with the bracket bearing, providing an initial preload; when the rubber body is compressed to the point that its end face is lower than the end face of the wave spring, the wave spring begins to contact the bearing and provides a secondary preload.

[0031] The present invention has been described in detail above through specific embodiments and examples, but these are not intended to limit the present invention. Many modifications and improvements can be made by those skilled in the art without departing from the principles of the present invention, and these should also be considered within the scope of protection of the present invention.

Claims

1. A pre-tightening nut structure for preventing rubber body from coming off, characterized in that, It includes a nut body, a rubber body, and a wave spring; the head of the rubber body is fixedly connected to the nut body by embedding its outer peripheral protrusion into a corresponding groove; the wave spring is disposed between the tail of the rubber body and the nut body; the inner diameter of the wave spring is larger than the outer diameter of the head of the rubber body and smaller than the outer diameter of the tail of the rubber body.

2. The pre-tightening nut structure for preventing rubber body detachment according to claim 1, characterized in that, The outer end face of the tail of the rubber body is higher than the outer end face of the wave spring.

3. The pre-tightening nut structure for preventing rubber body detachment according to claim 1, characterized in that, The outer periphery of the head of the rubber body has a trapezoidal cross-section.

4. The pre-tightening nut structure for preventing rubber body detachment according to claim 1, characterized in that, The outer periphery of the head of the rubber body has a semi-circular protrusion.

5. The pre-tightening nut structure for preventing rubber body detachment according to claim 1, characterized in that, The stiffness coefficient of the wave spring is greater than that of the rubber body.

6. An electric power steering system, characterized in that, Includes a pre-tightening structure for preventing rubber body dislodgement as described in any one of claims 1 to 5, wherein the pre-tightening nut is disposed on the housing of the electric power steering system and is used to adjust the meshing tightness of the worm gear and worm of the electric power steering system.

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