WO2021213138A1

WO2021213138A1 - Low friction sealing system for shock absorber

Info

Publication number: WO2021213138A1
Application number: PCT/CN2021/083524
Authority: WO
Inventors: 杜杰; 陈小芳; 李玉胜
Original assignee: 烟台润蚨祥油封有限公司
Priority date: 2020-04-21
Filing date: 2021-03-29
Publication date: 2021-10-28
Also published as: CN212106763U; PL130369U1

Abstract

A low friction sealing system for a shock absorber, comprising an oil seal, a dust-proof seal and a support ring (8) provided between the oil seal and the dust-proof seal; the oil seal comprises an oil seal body and a positioning framework (4), and the oil seal body comprises at least one sealing lip (7); the dust-proof seal comprises a dust-proof seal body and a support framework (2) for supporting the dust-proof seal body; the dust-proof seal body comprises at least one dust-proof lip (1), the support framework (2) is provided on the positioning framework (4), the support ring (8) comprises at least two support ring lip ports (11), and the oil seal body is made of a rubber material; and the support ring (8) is made of a PTFE material. A main sealing lip section of the sealing system is divided into two parts made of different materials, keeping the high sealing performance of a rubber material, and improving the high pressure resistance and the low friction performance of the PTFE material. Compared with an existing sealing piece of a single-cylinder shock absorber, the friction force between the sealing system and a shock absorber shaft can be reduced by 50% or more, improving the response speed of the shock absorber, and prolonging the service life of the sealing system.

Description

A low-friction sealing system of shock absorber

Technical field

The invention relates to a low-friction sealing system of a shock absorber, belonging to the technical field of monotube shock absorber sealing.

Background technique

The advantages of monotube shock absorbers are simple structure, fast response speed and good shock absorption effect. However, because the air and oil chambers of the single-tube shock absorber are arranged in-line, the seal is directly subjected to the pressure of the piston upper chamber, so the seal is required to have a high pressure bearing capacity, and sometimes it is even required to reach a pressure above 20 MPa at room temperature. . Considering the pressure requirements, the thickness of the waist rubber will be increased in the design of the single-tube shock absorber seal, which will also obtain a larger radial holding force than the general structural seal, which will also bring greater friction. Negative impact. In the single-tube shock absorber, in addition to the greater axial holding force brought by the seal structure, the high pressure acting on the rubber body at the waist of the seal further increases the axial holding force. The two work together to make the single-tube shock absorber The friction between the seal and the shaft is abnormally large.

Under the action of the internal pressure of the shock absorber, the seal of the single-tube shock absorber will fit the inner hole of the seal closer to the shock absorber shaft, which means that the main sealing position of the inner hole of the seal and the shock absorber There is a larger contact area between the shafts. Large friction and large contact area will make the main sealing lip of the single-tube shock absorber seal more severely worn, and the consequence is that the sealing performance and service life of the seal will be reduced.

In addition, the existing seals of the existing single-tube shock absorbers mainly have two structures, respectively, as shown in Figure 1 for the combined structure and Figure 2 for the integrated structure. In the two existing seal structures, the main sealing lip area is made of rubber, and the friction coefficient of rubber is much larger than that of PTFE.

Summary of the invention

Aiming at the shortcomings of the prior art, the present invention provides a low-friction sealing system for shock absorbers with simple structure, convenient assembly, high sealing performance, high pressure resistance and low friction.

The technical solution of the present invention to solve the above technical problems is as follows: a low-friction sealing system of a shock absorber, comprising an oil seal, a dust seal, and a support ring arranged between the oil seal and the dust seal, the oil seal including an oil seal body And a positioning frame, the oil seal body includes at least one sealing lip; the dust seal includes a dust seal body and a support frame for supporting the dust seal body, the dust seal body includes at least one dust lip, so The support frame is arranged on the positioning frame, the support ring includes at least two support ring lips, the oil seal body is made of rubber, and the support ring is made of PTFE.

The beneficial effect of the present invention is that the main sealing area of the lip of the sealing system includes a first sealing lip section A and a second sealing lip section B of different materials. Among them, the first sealing lip section A is made of rubber material with a thinner thickness structure, which has the auxiliary effect of holding the spring; the second sealing lip section B is made of PTFE material with low friction coefficient, which reduces the shock absorber shaft The friction force between them also guarantees the pressure requirements of the sealing system. The main sealing lip section of the sealing system is set as two parts with different materials, which not only retains the high sealing performance of rubber material, but also increases the high pressure resistance and low friction of PTFE material. Compared with the existing seals of single-tube shock absorbers, this patented solution can reduce the friction between the sealing system and the shock absorber shaft by more than 50%, improve the response speed of the shock absorber, and also extend the seal The service life of the system.

On the basis of the above technical solution, the present invention can also be improved as follows.

Further, an installation space for accommodating the support ring is formed between the dust seal and the oil seal body.

The beneficial effect of adopting the above-mentioned further solution is that the support ring is installed in the dust seal body, the bottom of the support frame and the inside of the oil seal body to ensure that the support ring is partially surrounded by the dust seal and the oil seal, and the installation is stable.

Further, the inner side of the oil seal body is provided with an annular groove, and the outer circumference of the support ring is provided with an inclined surface matching the annular groove.

The beneficial effect of adopting the above-mentioned further solution is that the inclined surface of the outer circumference of the support ring is assembled into a sealing system and closely fits with the annular groove of the inner hole of the waist of the oil seal rubber body.

Further, the diameter of the second support ring lip close to the sealing lip is the smallest, and the diameter of the other support ring lip is at least 0.1 mm larger than the diameter of the second support ring lip. .

The beneficial effect of adopting the above-mentioned further solution is that it not only satisfies the requirements of high sealing performance, but also satisfies the requirements of low friction.

Further, the included angle between the air surface of the second support ring lip and the shock absorber shaft is 20-36°.

The beneficial effect of adopting the above-mentioned further solution is that the lip of the support ring and the axis are at a certain angle to meet the requirements of support and sealing.

Further, the included angle between the air surface of the second support ring lip and the shock absorber shaft is 28°.

The beneficial effect of adopting the above-mentioned further solution is that not only the sealing effect is better, but also the supporting effect is better.

Further, the oil seal body further includes a lower end surface annular static seal, and the lower end surface annular static seal is arranged at the bottom of the positioning frame.

The beneficial effect of adopting the above-mentioned further solution is that the annular static seal on the lower end surface is similar to the O-ring structure design, and is in interference fit with a plane of the guide, which becomes the first guarantee for the outer diameter seal of the sealing system.

Further, the dust-proof seal body further includes an upper end surface annular static seal, and the upper end surface annular static seal is arranged on the outside of the support frame.

The beneficial effect of adopting the above-mentioned further solution is that the annular static seal on the upper end surface is another guarantee for the outer diameter seal of the sealing system.

Further, an inner concave annular groove is provided on the outer circumference of the oil seal body, and a holding spring is arranged in the inner concave annular groove.

The beneficial effect of adopting the above-mentioned further solution is to increase or compensate the sealing force.

Further, the positioning frame has an L-shaped structure, and a positioning space for accommodating the support frame is provided on the positioning frame.

The beneficial effect of adopting the above-mentioned further solution is that the horizontal and numerical contact parts of the L-shaped positioning frame form a positioning angle space, which is convenient for stable positioning and supporting the frame.

Description of the drawings

Figure 1 is a schematic view of the structure of the existing combined monotube shock absorber seal;

Figure 2 is a schematic view of the structure of the existing one-piece single-tube shock absorber seal;

Figure 3 Schematic diagram of the low-friction sealing system of the present invention;

4 is a schematic diagram of the structure of the dust seal in the sealing system of the present invention;

Figure 5 is a schematic diagram of the structure of the oil seal in the sealing system of the present invention;

Figure 6 is a schematic structural diagram of a support ring in the sealing system of the present invention;

Figure 7 is a schematic structural diagram of the sealing system of the present invention in use;

In the figure, 1. Dust lip; 2. Support frame; 3. Upper end face annular static seal; 4. Positioning frame; 5. Lower end face annular static seal; 6. Hold spring; 7. Seal lip; 8. Support ring ; 9. Guide; 10. Shock absorber shaft; 11. Support ring lip; 12. Inclined surface.

Detailed ways

The principles and features of the present invention will be described below in conjunction with examples. The examples cited are only used to explain the present invention and are not used to limit the scope of the present invention.

As shown in Figure 3-7, a low-friction sealing system for a shock absorber includes an oil seal, a dust seal, and a support ring 8 arranged between the oil seal and the dust seal. The oil seal includes an oil seal body and The positioning frame 4, the oil seal body includes at least one sealing lip 7; the dust seal includes a dust seal body and a support frame 2 for supporting the dust seal body, the dust seal body includes at least one dust lip 1. The support frame is arranged on the positioning frame, the support ring includes at least two support ring lips 11, the oil seal body is made of rubber, and the support ring is made of PTFE. The oil seal body is vulcanized and connected to the positioning frame, and the dust seal body is vulcanized and fixedly connected to the support frame.

An installation space for accommodating the support ring is formed between the dust seal and the oil seal body. The support ring is installed in the dust seal body, the bottom of the support frame and the inside of the oil seal body to ensure that the support ring part is surrounded by the dust seal and the oil seal, and the installation is stable.

The inner side of the oil seal body is provided with an annular groove, and the outer circumference of the support ring is provided with an inclined surface 12 that matches with the annular groove. The inclined surface of the outer circumference of the support ring is assembled into a sealing system and closely fits with the annular groove of the inner hole of the waist of the oil seal rubber body.

The position marked on the support ring lip 11 in Figures 3 and 4 is the position of the second support ring lip. The second support ring lip close to the sealing lip has the smallest diameter size, and the other support ring lip The diameter of the mouth is at least 0.1 mm larger than the diameter of the lip of the second support ring. It not only meets the requirements of high tightness, but also meets the requirements of low friction.

The angle between the air surface of the second support ring lip and the shock absorber shaft is 20-36°. The lip of the support ring is at a certain angle with the axis to meet the requirements of support and sealing.

The angle between the air surface of the second support ring lip and the shock absorber shaft is 28°. Not only the sealing effect is better, but also the supporting effect is better.

The oil seal body also includes a lower end surface annular static seal 5, and the lower end surface annular static seal is arranged at the bottom of the positioning frame. The annular static seal on the lower end surface is similar to the O-ring structure design, and is matched with a plane interference of the guide 9 to become the first guarantee for the outer diameter seal of the sealing system.

The dust-proof seal body also includes an upper end surface annular static seal 3, and the upper end surface annular static seal is arranged on the outside of the support frame. The annular static seal on the upper end face is another guarantee for the outer diameter seal of the sealing system.

An inner concave annular groove is provided on the outer circumference of the oil seal body, and a holding spring 6 is arranged in the inner concave annular groove. Increase or compensate the sealing force.

The positioning frame 4 has an L-shaped structure, and a positioning space for accommodating the supporting frame is provided on the positioning frame. The level of the L-shaped positioning frame and the numerical value contact position form a positioning angle space, which is convenient for stable positioning and supporting the frame.

The oil seal, dust seal and support ring are assembled into a sealing system through structural positioning. The main sealing section of the lip of the sealing system includes a first sealing lip section A and a second sealing lip section B of different materials, as shown in Figs. 3 and 7. The first sealing lip section is made of rubber material and has a thinner thickness structure, which has the auxiliary effect of holding the spring. The second sealing lip section B is made of PTFE with a low friction coefficient, which reduces the friction with the shock absorber shaft and at the same time ensures the pressure requirement of the sealing system. The patented solution not only retains the high sealing performance of the rubber sealing lip, but also increases the high pressure resistance and low friction of the PTFE sealing lip.

The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

A low-friction sealing system for a shock absorber, which is characterized in that it includes an oil seal, a dust seal, and a support ring arranged between the oil seal and the dust seal. The oil seal includes an oil seal body and a positioning frame. The body includes at least one sealing lip; the dust-proof seal includes a dust-proof seal body and a support frame for supporting the dust-proof seal body, the dust-proof seal body includes at least one dust-proof lip, and the support frame is arranged on the On the positioning framework, the support ring includes at least two support ring lips, the oil seal body is made of rubber, and the support ring is made of PTFE.
The low-friction sealing system for a shock absorber according to claim 1, wherein an installation space for accommodating the support ring is formed between the dust seal and the oil seal body.
The low-friction sealing system of a shock absorber according to claim 1, wherein the inner side of the oil seal body is provided with an annular groove, and the outer circumference of the support ring is provided with an inclined surface matching the annular groove.
The low-friction sealing system of the shock absorber according to claim 2, wherein the inner side of the oil seal body is provided with an annular groove, and the outer circumference of the support ring is provided with an inclined surface matching the annular groove.
The low-friction sealing system of the shock absorber according to claim 1, wherein the diameter of the second support ring lip near the sealing lip is the smallest, and the diameter of the other support ring lip is It is at least 0.1mm larger than the diameter of the second support ring lip.
The low-friction sealing system of the shock absorber according to claim 5, wherein the included angle between the air surface of the second support ring lip and the shock absorber shaft is 20-36°.
The low-friction sealing system of the shock absorber according to claim 6, wherein the included angle between the air surface of the second support ring lip and the shock absorber shaft is 28°.
The low-friction sealing system of a shock absorber according to claim 1, wherein the oil seal body further comprises a lower end surface annular static seal, and the lower end surface annular static seal is arranged at the bottom of the positioning frame.
The low-friction sealing system of a shock absorber according to claim 1, wherein the dust-proof seal body further comprises an upper end surface annular static seal, and the upper end surface annular static seal is arranged on the outside of the support frame.
The low-friction sealing system of a shock absorber according to claim 1, wherein an inner concave annular groove is provided on the outer circumference of the oil seal body, and a holding spring is provided in the inner concave annular groove.
The low-friction sealing system of a shock absorber according to claim 1, wherein the positioning frame is an L-shaped structure, and a positioning space for accommodating the support frame is provided on the positioning frame.