Sealing structure of electric power steering gear

Abstract

The utility model discloses an electric power steering gear sealing structure, and relates to the technical field of electric power steering gear sealing, the electric power steering gear sealing structure comprises a shell and an input shaft, a double-sealing assembly is arranged at the joint of the input shaft and the shell, the double-sealing assembly comprises a first sealing ring, a second sealing ring, a third sealing ring and a fourth sealing ring, the second sealing ring is arranged on the input shaft in a sleeving mode and located at the inner side end of the shell; and the dustproof cover is connected to the outer side of the shell. The first sealing ring and the second sealing ring form a double-sealing defensive line, dynamic sealing and static sealing are combined, the leakage probability of lubricating grease is remarkably reduced, meanwhile, multi-stage blocking is formed on external pollutants, the protection capacity of internal components of the steering gear is improved, the corrugated pipe dust cover is matched with a hoop to be fixed, the exposed part of the input shaft is tightly wrapped, and the service life of the steering gear is prolonged. The telescopic structure adapts to movement of the input shaft, long-term dustproof and waterproof effects are guaranteed through wear-resistant and weather-resistant materials, and damage of pollutants to the interior of the steering gear is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to electric power assisted steering gear seal technical field, concretely relates to a kind of electric power assisted steering gear sealing structure. BACKGROUND

[0002] With the development of automobile industry, electric power assisted steering gear (EPS) is widely applied due to energy saving, fast response and other advantages. However, its sealing problem has been the focus of the industry:

[0003] Single sealing structure: most electric power assisted steering gears only use single seal, such as single lip oil seal or ordinary O-ring. Single seal is easily affected by vehicle driving vibration and temperature change during long-term use. For example, the sealing material expands and deforms in high temperature environment, and shrinks and hardens at low temperature, resulting in sealing gap and increased risk of grease leakage. At the same time, single sealing surface has insufficient protection ability when facing external complex environment (such as dust and water splashing), and pollutants can easily enter the inside of the steering gear, destroy the lubrication environment and accelerate the wear of parts.

[0004] Design defect of dustproof structure: although some steering gears are provided with dust cover, the structure design is simple. For example, the dust cover is not firmly connected with the input shaft, and it is easy to loosen during vehicle driving, so dust and water can still enter through the gap. In addition, the traditional dust cover has poor wear resistance, and the surface is worn out after long-term use, losing the dustproof function.

[0005] Insufficient protection of grease cavity: as a key lubricating medium inside the steering gear, the existing sealing structure has limited protection for the grease cavity. Once the sealing fails, not only the grease leakage will cause waste, but also the lubrication of the input shaft and other parts will be poor, which will cause abnormal wear and even affect the normal operation of the motor, increasing the maintenance cost.

[0006] Therefore, the development of an electric power assisted steering gear sealing structure becomes the key to solving the above problems. INVENTION CONTENTS

[0007] The utility model aims at providing an electric power assisted steering gear sealing structure to solve the problems raised in the background.

[0008] To solve the above technical problems, the utility model adopts the technical scheme of:

[0009] An electric power assisted steering gear sealing structure, comprising a housing and an input shaft, a double sealing assembly is provided at the connection between the input shaft and the housing, and the double sealing assembly comprises:

[0010] A first sealing ring is sleeved on the input shaft and located at the outer side end of the housing.

[0011] A second sealing ring is sleeved on the input shaft and located at the inner side end of the housing.

[0012] A dust cover is connected to the outside of the housing and covers the exposed part of the input shaft.

[0013] Preferably, the first sealing ring is a double-lip skeleton oil seal, comprising a main lip and a secondary lip, the main lip is in interference fit with the input shaft, and the secondary lip faces the outside of the housing.

[0014] Preferably, the second sealing ring is an O-shaped sealing ring, which is embedded in an annular groove on the inside of the housing and is in clearance fit with the input shaft.

[0015] Preferably, the dust cover is a bellows structure, one end of which is fixed to the housing, and the other end is fixed to the input shaft through a clamp.

[0016] Preferably, a grease cavity is further arranged between the housing and the input shaft, which is located on the inside of the second sealing ring.

[0017] Preferably, the dust cover is a bellows structure, and the surface of the bellows is provided with a wear-resistant coating, and the material of the wear-resistant coating is polytetrafluoroethylene.

[0018] Compared with the prior art, the technical progress achieved by the utility model is:

[0019] 1. The utility model provides a kind of electric power assisted steering gear sealing structure, and first sealing ring and second sealing ring form double sealing defense line, dynamic sealing is combined with static sealing, significantly reduce the probability of grease leakage, while forming multistage barrier to external pollutants, improve the protection capability of the internal components of steering gear.

[0020] 2. The utility model provides a kind of electric power assisted steering gear sealing structure, and bellows dust cover cooperates clamp and is fixed, tightly wraps exposed part of input shaft, telescopic structure adapts to the movement of input shaft, and wear-resistant weather-resistant material ensures long-term dustproof and waterproof effect, reduces the damage of pollutants to the inside of steering gear.

[0021] 3. The utility model provides a kind of electric power assisted steering gear sealing structure, and grease cavity is maintained under double sealing protection, and internal grease stock is stable, reduces the lubrication problem caused by leakage, prolongs steering gear maintenance cycle, and reduces use cost. DETAILED DESCRIPTION

[0022] Figure 1 It is the partial structure schematic view of the housing and dust cover of the utility model;

[0023] Figure 2 It is the partial structure schematic view of the right view of the housing of the utility model;

[0024] Figure 3 It is the structure schematic view of double sealing assembly of the utility model;

[0025] Figure 4 It is the first sealing ring structure detail schematic view of the utility model.

[0026] In the drawing: 1, shell; 2, input shaft; 3, double sealing assembly; 4, first sealing ring; 5, second sealing ring; 6, dust cover; 7, clamp; 8, lubricating grease cavity; 11, annular groove; 41, main lip; 42, auxiliary lip. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model.

[0028] Embodiment 1

[0029] As shown in the drawing, Figures 1-4 The utility model provides a kind of electric power steering gear sealing structure, including shell 1 and input shaft 2, input shaft 2 and shell 1 junction are provided with double sealing assembly 3, and double sealing assembly 3 includes:

[0030] First sealing ring 4, is set on input shaft 2, is located at the outside end of shell 1;

[0031] Second sealing ring 5, is set on input shaft 2, is located at the inside end of shell 1;

[0032] Dust cover 6 is connected to the outside of shell 1, and is covered on the exposed part of input shaft 2.

[0033] Embodiment 2

[0034] As shown in the drawing, Figures 1-4 On the basis of embodiment 1, the utility model provides a kind of technical scheme: preferably, first sealing ring 4 is double-lip skeleton oil seal, including main lip 41 and auxiliary lip 42, and main lip 41 is interference fit with input shaft 2, forms dynamic seal in the process of input shaft 2 rotation, effectively prevents lubricating grease from leaking to the outside of shell 1.Auxiliary lip 42 is towards the outside of shell 1, and utilizes lip structure to block external dust, moisture and other pollutants, plays the role of preliminary dustproof waterproof.Bone frame of the inside of skeleton oil seal provides structural support for oil seal, prevents oil seal from deforming under high-speed rotation or stress, ensures sealing stability.

[0035] Auxiliary lip 42 is towards the outside of shell 1.

[0036] Second sealing ring 5 is O-shaped sealing ring, is embedded in the annular groove 11 of the inside of shell 1, and is gap fit with input shaft 2.O-shaped sealing ring is gap fit with input shaft 2, forms static seal defense line in the inside of shell 1.The design of annular groove 11 can accurately position O-shaped sealing ring, ensure that it remains stable state after assembly, make up the possible tiny leakage of first sealing ring 4, further improve sealing effect.

[0037] The dust cover 6 is a bellows structure, which has good flexibility and can adapt to the slight displacement of the input shaft 2 in operation. One end of the dust cover 6 is fixed to the housing 1, and the other end is fixed to the input shaft 2 through the clamp 7. The adjustability of the clamp 7 ensures that the dust cover 6 closely fits the input shaft 2, avoiding the occurrence of gaps. The bellows material has weather resistance and can resist the influence of environmental factors such as ultraviolet rays and high and low temperatures. The surface can be further sprayed with a wear-resistant coating to prolong the service life of the dust cover 6 and effectively block the intrusion of external pollutants into the inside of the steering gear.

[0038] A lubricating grease cavity 8 is further arranged between the housing 1 and the input shaft 2 and is located inside the second sealing ring 5. The lubricating grease stored in the lubricating grease cavity 8 can continuously lubricate the contact area between the input shaft 2 and the housing 1, thereby reducing the friction loss of the components. The design of the double sealing assembly 3 can effectively protect the lubricating grease cavity 8 and prevent the leakage of lubricating grease, thereby maintaining the stability of the internal lubricating environment.

[0039] The dust cover 6 is a bellows structure, and the surface of the bellows is provided with a wear-resistant coating. The material of the wear-resistant coating is polytetrafluoroethylene.

[0040] Example 3

[0041] As shown in Figures 1-4 Based on the embodiment 1, the utility model provides a technical scheme: preferably, the following steps are carried out in the use process:

[0042] Component preparation:

[0043] Check whether the double-lip structure of the first sealing ring 4 is complete, whether the main lip 41 and the auxiliary lip 42 are damaged, and whether the metal skeleton of the skeleton oil seal is deformed.

[0044] Confirm that the size of the O-shaped sealing ring of the second sealing ring 5 matches the annular groove 11 inside the housing 1, and that the surface is free of scratches.

[0045] The bellows of the dust cover 6 has no creases, the clamp 7 has no rust, and the adjustment function is normal.

[0046] Assembly process:

[0047] Embed the second sealing ring 5 into the annular groove 11 inside the housing 1 to ensure that the O-shaped sealing ring falls completely into the groove without distortion.

[0048] Sleeve the first sealing ring 4 on the input shaft 2, with the main lip 41 facing the inside of the housing 1 and the auxiliary lip 42 facing the outside of the housing 1. Press-fit through a special tool to ensure that the main lip 41 tightly fits the input shaft 2 with interference.

[0049] Assemble the input shaft 2 to the housing 1, and at this time, the second sealing ring 5 forms a static seal inside the housing 1.

[0050] Install one end of the dust cover 6 on the preset mounting position on the outside of the housing 1, and fix the other end to the exposed part of the input shaft 2 by the clamp 7. Adjust the tightness of the clamp 7 to make the dust cover 6 tight and wrinkle-free, so as to ensure the sealing and dust prevention effect.

[0051] The working principle of the sealing structure of this electric power steering system will be explained in detail below.

[0052] like Figures 1-4 As shown, when the electric power steering is working, the input shaft 2 rotates, and the main lip 41 of the first sealing ring 4 rotates with the input shaft 2, preventing grease in the grease cavity 8 from leaking to the outside of the housing 1 through an interference fit; the secondary lip 42 blocks external dust and moisture. The second sealing ring 5 inside the housing provides secondary protection against any minor leaks that may occur through the first sealing ring 4, ensuring the grease cavity 8 is sealed. The dust cover 6 extends and retracts with the movement of the input shaft 2, and its bellows structure cooperates with the clamp 7 to prevent external contaminants from contacting the sealing area between the input shaft 2 and the housing 1, forming multiple layers of protection.

[0053] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sealing structure for an electric power steering system, comprising a housing (1) and an input shaft (2), characterized in that: A double sealing assembly (3) is provided at the connection between the input shaft (2) and the housing (1), the double sealing assembly (3) comprising: The first sealing ring (4) is sleeved on the input shaft (2) and located at the outer end of the housing (1); The second sealing ring (5) is sleeved on the input shaft (2) and located on the inner end of the housing (1); A dust cover (6) is attached to the outside of the housing (1) and covers the exposed part of the input shaft (2).

2. The sealing structure for an electric power steering system according to claim 1, characterized in that: The first sealing ring (4) is a double-lip skeleton oil seal, including a main lip (41) and a secondary lip (42). The main lip (41) is interference-fitted with the input shaft (2), and the secondary lip (42) faces the outside of the housing (1).

3. The sealing structure of an electric power steering system according to claim 1, characterized in that: The second sealing ring (5) is an O-ring, which is embedded in the annular groove (11) on the inner side of the housing (1) and has a clearance fit with the input shaft (2).

4. The sealing structure of an electric power steering system according to claim 1, characterized in that: The dust cover (6) is a corrugated pipe structure, with one end fixed to the housing (1) and the other end fixed to the input shaft (2) by a clamp (7).

5. The sealing structure of an electric power steering system according to claim 1, characterized in that: A grease cavity (8) is also provided between the housing (1) and the input shaft (2), located inside the second sealing ring (5).

6. The sealing structure of an electric power steering system according to claim 1, characterized in that: The dust cover (6) is a corrugated pipe structure, and the surface of the corrugated pipe is provided with a wear-resistant coating, which is made of polytetrafluoroethylene.

Images