Rubber for oil seal, oil seal structure, and shock absorber

Abstract

The application discloses a rubber for oil seal, an oil seal structure and a shock absorber, and relates to the technical field of sealing. The rubber for oil seal is provided with a pressure relief lip, so that the pressure relief function of the oil seal can be realized, the impact of high-pressure oil injection and the like on the oil seal is reduced, and the service life of the oil seal is prolonged, thereby solving the problem that the service life of the ordinary oil seal is short due to the fact that the ordinary oil seal cannot relieve pressure. In addition, the high-pressure oil injection is difficult to open the lip opening of the pressure relief lip, so that the subsequent oil sealing lip opening does not need too large a holding force, and therefore the spring holding outside the oil sealing lip opening can be selected, and the problem that the holding force of the oil seal lip opening is too large due to the use of a metal retainer can be avoided. The oil seal structure and the shock absorber both comprise the above-mentioned rubber for oil seal, and have all the characteristics of the above-mentioned rubber for oil seal, and details are not described herein again.

Description

Technical Field

[0001] This invention relates to the field of sealing technology, and in particular to a rubber seal for oil seals, an oil seal structure, and a shock absorber. Background Technology

[0002] Oil seals are commonly used sealing components, often found in structures such as shock absorbers. Taking the oil seal in a shock absorber as an example... Figure 1 As shown, the shock absorber comprises a piston rod 1, an oil seal 2, a guide 3, a shock absorber working cylinder 4, and an oil reservoir 5. The piston rod 1 is connected to a piston at its end and reciprocates during operation. When the shock absorber is stretched, the piston, driven by the piston rod 1, compresses the damping oil 6 in the shock absorber working cylinder 4, increasing the oil pressure and generating damping force. During this process, the high-pressure damping oil is sprayed through the gap between the piston rod 1 and the guide 3 onto the lip of the oil seal 2. The structure of a conventional oil seal 2 is as follows... Figure 2 As shown, the oil seal 2 consists of three parts: a spring 2-1, a rubber 2-2, and a metal frame 2-3. The rubber 2-2 and the metal frame 2-3 are vulcanized together. The oil sealing lip 2-4 of the rubber 2-2 is externally fitted with the spring 2-1. Under high-pressure oil injection, the lip of the oil seal 2-4 will open, causing the oil seal 2 to lose its sealing ability and resulting in oil leakage. Therefore, it cannot seal the high-pressure injected oil in the shock absorber.

[0003] Currently, there are some existing technologies for heavy-duty shock absorber oil seal structures, such as Figure 3 As shown, a metal retainer 2-6 is designed outside the sealing lip 2-4 to replace the spring 2-1. The metal retainer 2-6 can be vulcanized integrally with the rubber 2-2, or it can be assembled onto the rubber 2-2. This structure increases the clamping force between the sealing lip 2-4 and the piston rod 1 to counteract the impact of high-pressure injected oil on the lip of the sealing lip 2-4, thus achieving a seal for high-pressure oil. However, the disadvantages of this structure are also very obvious: it cannot achieve pressure relief, the lip is subjected to large impact forces, affecting the service life of the oil seal; moreover, the large clamping force between the sealing lip 2-4 and the piston rod 1 leads to excessive friction between the two, accelerating lip wear, further shortening the service life of the oil seal, and resulting in poor sealing performance in the later stages of use. Summary of the Invention

[0004] The purpose of this invention is to provide a rubber seal for oil seals, an oil seal structure, and a shock absorber to solve the problem of short service life of existing oil seals due to their inability to release pressure.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] The application provides a rubber for oil seal, which is a hollow annular structure, wherein a pressure relief lip, an oil sealing lip and a dust lip are sequentially arranged on an inner annular surface of the rubber for oil seal along an oil leakage direction, the pressure relief lip is inclined in a converging manner towards a direction away from the oil sealing lip, an included angle alpha between the pressure relief lip and an axis of the inner annular surface is 45-90 degrees, and in a radial direction of the inner annular surface, the pressure relief lip protrudes from the oil sealing lip, and in an axial direction of the inner annular surface, the pressure relief lip protrudes from an edge of the rubber for oil seal.

[0007] Optionally, the thickness t of the pressure relief lip is 0.5-1.5 mm.

[0008] Optionally, an axial height h1 of the pressure relief lip protruding from the edge of the rubber for oil seal is 0.2-2 mm.

[0009] Optionally, an oil scraping lip is further arranged on the inner annular surface, the oil scraping lip is located between the oil sealing lip and the dust lip, and is arranged close to the dust lip.

[0010] Optionally, an axial height h2 between a lip of the oil scraping lip and a lip of the dust lip is 0.5-2 mm.

[0011] The application further provides an oil seal structure, which comprises a framework, a rubber holding member and the rubber for oil seal, the framework is embedded in an outer periphery of the rubber for oil seal, the oil sealing lip is externally fitted with the rubber holding member, and the rubber holding member is used for providing a holding force for the rubber for oil seal.

[0012] Optionally, the rubber holding member is a spring.

[0013] Optionally, the framework is a metal framework.

[0014] Optionally, the metal framework is integrated with the rubber for oil seal by vulcanization.

[0015] The application further provides a shock absorber, which comprises a piston rod, a guide and the oil seal structure, the oil seal structure is fitted at a gap between the piston rod and the guide, the piston rod passes through a hollow inner ring of the rubber for oil seal, and the piston rod is dynamically sealed with the inner annular surface of the rubber for oil seal.

[0016] The application has the following technical effects relative to the prior art:

[0017] The oil seal rubber provided by the application can realize the pressure relief function of the oil seal by setting the pressure relief lip, reduces the impact of high-pressure oil injection and the like on the oil seal, thereby improving the service life of the oil seal, and solves the problem of short service life of the ordinary oil seal caused by the inability of the ordinary oil seal to relieve pressure.

[0018] In some technical solutions disclosed in the application, an oil scraping lip is further arranged between the oil sealing lip and the dustproof lip of the oil seal rubber, the oil scraping lip can cooperate with the dustproof lip to play a double dustproof role, and can scrape the oil film on the piston rod, thereby reducing the thickness of the oil film taken out by the piston rod, and the oil film can be taken back into the shock absorber in the compression process of the shock absorber, so that the oil loss amount can be effectively reduced.

[0019] The oil seal structure and the shock absorber provided by the application both comprise the oil seal rubber described above, and have all the characteristics of the oil seal rubber described above, and details are not described herein again. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0021] Figure 1 It is a structural schematic diagram of the prior shock absorber;

[0022] Figure 2 It is a structural schematic diagram of the prior oil seal based on spring clamping;

[0023] Figure 3 It is a structural schematic diagram of the prior oil seal based on metal retainer clamping;

[0024] Figure 4 It is a structural schematic diagram of the oil seal structure disclosed in the embodiments of the application;

[0025] Figure 5 It is a parameter marking schematic diagram of the oil seal structure disclosed in the embodiments of the application;

[0026] Figure 6 It is an installation principle diagram of the oil seal structure disclosed in the embodiments of the application.

[0027] In the drawings, the reference signs are as follows:

[0028] Piston rod 1, oil seal 2, spring 2-1, rubber 2-2, metal skeleton 2-3, oil sealing lip 2-4, dustproof lip 2-5, metal cage 2-6, guide 3, shock absorber working cylinder 4, oil reservoir 5, shock absorber oil 6;

[0029] 7. Oil seal structure; 8. Rubber for oil seal; 8-1. Pressure relief lip; 8-2. Oil scraper lip; 9. Rubber clamping part; 10. Skeleton. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] One of the objectives of this invention is to provide a rubber for oil seals to solve the problem of short service life of existing oil seals due to their inability to release pressure.

[0032] Another object of the present invention is to provide an oil seal structure comprising the above-mentioned oil seal rubber.

[0033] Another object of the present invention is to provide a shock absorber comprising the above-described oil seal structure.

[0034] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] like Figures 4 to 6 As shown, this embodiment provides a rubber 8 for oil seals, which is a traditional hollow annular ring, with the hollow inner ring used for the piston rod and other sealing components to pass through. The difference from existing technologies lies in that this solution has a pressure relief lip 8-1, an oil sealing lip 2-4, and a dustproof lip 2-5 sequentially arranged on the inner ring surface of the rubber 8 along the oil leakage direction. The pressure relief lip 8-1 is inclined in a constricted shape, facing away from the oil sealing lip 2-4, and the angle α between the pressure relief lip 8-1 and the axis of the inner ring surface is 45° to 90°. Figure 4 and Figure 5 As shown, the pressure relief lip 8-1 is generally a structure with uniform thickness. The angle α between it and the axis of the inner ring surface can be taken as the reference of the axis of the pressure relief lip 8-1 perpendicular to the thickness direction. For the specific position of the angle α, please refer to [reference needed]. Figure 5 In the radial direction of the inner annular surface, the pressure relief lip 8-1 protrudes beyond the oil sealing lip 2-4, and in the axial direction of the inner annular surface, the pressure relief lip 8-1 protrudes beyond the edge of the oil seal rubber 8.

[0037] As a preferred solution, the thickness t of the pressure relief lip 8-1 is 0.5mm-1.5mm.

[0038] Further, in this embodiment, the axial height h1 of the pressure relief lip 8-1 protruding from the edge of the oil seal rubber 8 is preferably 0.2mm-2mm.

[0039] The working principle and effects of the oil seal rubber 8 will be described in detail below by taking the application of the above-mentioned oil seal rubber 8 in the oil seal of a shock absorber as an example.

[0040] As shown in Figure 6 the assembled state, the pressure relief lip 8-1, the oil seal lip 2-4 and the dust seal lip 2-5 on the inner ring surface of the oil seal rubber 8 are all in dynamic sealing with the outer wall of the piston rod 1 of the shock absorber. The pressure relief lip 8-1 itself has an inclined structure, and after assembly, it is pressed by the piston rod 1 with the end face downward, forming a lip opening against high-pressure injection, which can play a role in pressure relief of the oil seal lip opening. High-pressure oil injection is difficult to open the lip opening of the pressure relief lip 8-1, so that the two oil seal lips 2-4 behind it do not need excessive holding force, and therefore the outer lip opening of the oil seal lip 2-4 can be held by a spring, which can avoid the problem of excessive holding force of the oil seal lip opening caused by the use of a metal retainer.

[0041] The unique structural arrangement of the pressure relief lip 8-1 in the above-mentioned oil seal rubber 8, including the arrangement of the included angle a with the axis of the inner ring surface, the thickness t and the axial protruding height h1, can realize the pressure relief function of the oil seal, reduce the impact of high-pressure oil injection and other pressures on the oil seal, thereby improving the service life of the oil seal and solving the problem of short service life of ordinary oil seals caused by the inability to relieve pressure.

[0042] Embodiment Two

[0043] On the basis of the above-mentioned embodiment one, this embodiment further provides a scraping oil lip 8-2 on the inner ring surface of the oil seal rubber 8, which is located between the oil seal lip 2-4 and the dust seal lip 2-5 and is arranged close to the dust seal lip 2-5. As shown in Figure 4 and Figure 5 the axial height h2 between the lip opening of the scraping oil lip 8-2 and the lip opening of the dust seal lip 2-5 is preferably 0.5mm-2mm. After assembly, the scraping oil lip 8-2 is in sealing contact with the outer wall of the piston rod, and the scraping oil lip 8-2 has two main functions:

[0044] (1) It cooperates with the dust seal lip 2-5 to play a double dustproof role. The dust seal lip 2-5 provides the main dustproof function, and the scraping oil lip 8-2 can further block the entering dust between the dust seal lip 2-5 and the scraping oil lip 8-2, reducing the dust entering the oil seal lip opening.

[0045] (II) The oil scraping lip 8-2 can scrape the oil film on the piston rod 1, reduce the thickness of the oil film taken out by the piston rod 1, and bring the oil film back into the shock absorber during the compression of the shock absorber, thereby further reducing the oil loss.

[0046] Embodiment Three

[0047] The oil seal structure 7 disclosed in the embodiment comprises a skeleton 10, a rubber holding member 9, and the oil seal rubber 8 disclosed in Embodiment One or Embodiment Two. The skeleton 10 is embedded in the outer periphery of the oil seal rubber 8, and the rubber holding member 9 is assembled outside the oil seal lip 2-4. The rubber holding member 9 is used to provide a holding force for the oil seal rubber 8.

[0048] In the embodiment, the oil seal rubber 8 is provided with the pressure relief lip 8-1. In the normal sealing state, it is difficult for the high-pressure oil jet to open the lip of the pressure relief lip 8-1, so that the two oil seal lips 2-4 behind the pressure relief lip 8-1 do not need excessive holding force. Therefore, the rubber holding member 9 outside the oil seal lip 2-4 can be selected as a spring holding member, which can avoid the problem of excessive holding force of the oil seal lip caused by the use of a metal retainer. The holding force between the oil seal rubber 8 and the piston rod is greatly reduced, which can improve the friction between the lip of the oil seal lip 2-4 or the pressure relief lip 8-1 and the piston rod, reduce the wear of the lip, and further improve the service life of the oil seal structure 7 and the oil sealing effect.

[0049] In the embodiment, the skeleton 10 is preferably a metal skeleton, and the oil seal rubber 8 can be nitrile rubber, fluororubber, silicone rubber, acrylate rubber, polyurethane, polytetrafluoroethylene, etc. The metal skeleton is preferably integrated with the oil seal rubber 8 by vulcanization.

[0050] Embodiment Four

[0051] The shock absorber disclosed in the embodiment comprises a piston rod 1, a guide 3, and the oil seal structure 7 disclosed in Embodiment Three. The oil seal structure 7 is assembled at the gap between the piston rod 1 and the guide 3. The piston rod 1 passes through the hollow inner ring of the oil seal rubber 8 and dynamically seals with the pressure relief lip 8-1, the oil scraping lip 8-2, the oil seal lip 2-4, and the dust lip 2-5 on the inner ring surface of the oil seal rubber 8. The overall structure of the shock absorber is known in the prior art, and can be found in Figure 1 The specific structure of the oil seal structure 7 and the sealing principle of the oil seal rubber 8 are disclosed in Embodiments One to Three, and will not be described here.

[0052] It is to be understood that the application is not limited to the details of the above-exemplified embodiments and that the present application can be carried out in other concrete ways without departing from the spirit or essential characteristics of the application. Consequently, all changes and modifications that can suggest themselves to one skilled in the art have to be seen as being within the scope of the present application as defined by the following claims. The embodiments are to be considered in all respects as illustrative only and not restrictive of the application described and claimed herein. The application is therefore not to be limited to the specific embodiments described herein, but only by the scope of the appended patent claims and their equivalents.

[0053] The above examples are illustrative of the principles and embodiments of the application. They are not meant to limit the scope of the application, which is defined by the claims. The application is not limited to the specific details described herein.

Claims

1. A rubber for an oil seal, which is a hollow ring, characterized by, The inner ring surface is sequentially provided with a pressure relief lip, an oil sealing lip and a dustproof lip in the oil leakage direction, the pressure relief lip is inclined in a converging manner towards a direction away from the oil sealing lip, an included angle a between the pressure relief lip and an axis of the inner ring surface is 45°-90°, in the radial direction of the inner ring surface, the pressure relief lip is protruded from the oil sealing lip, in the axial direction of the inner ring surface, the pressure relief lip is protruded from the edge of the oil sealing rubber, a thickness t of the pressure relief lip is 0.5mm-1.5mm, an axial height h1 of the edge of the oil sealing rubber protruded from the pressure relief lip is 0.2mm-2mm, the inner ring surface is further provided with an oil scraping lip, the oil scraping lip is located between the oil sealing lip and the dustproof lip and is arranged close to the dustproof lip, an axial height h2 between a lip of the oil scraping lip and a lip of the dustproof lip is 0.5mm-2mm.

2. An oil seal structure characterized by comprising: The oil seal structure comprises a skeleton, a rubber holding member and the oil sealing rubber as claimed in claim 1, the skeleton is embedded in the outer periphery of the oil sealing rubber, the oil sealing lip is externally fitted with the rubber holding member, the rubber holding member is used to provide holding force for the oil sealing rubber, and the rubber holding member is a spring.

3. The oil seal structure according to claim 2, characterized by The skeleton is a metal skeleton.

4. The oil seal structure according to claim 3, characterized by The metal skeleton is integrated with the oil sealing rubber through vulcanization.

5. A shock absorber characterized by The oil seal structure is fitted at a gap between the piston rod and the guide, the piston rod passes through the hollow inner ring of the oil sealing rubber and dynamically seals with the inner ring surface of the oil sealing rubber.

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