Oil seal for single-cylinder shock absorber and single-cylinder shock absorber

Abstract

The oil seal comprises an oil seal body and a compensation framework arranged in the oil seal body, the compensation framework is provided with a sharp point, the oil seal body can swing left and right around the sharp point along with the compensation framework when bearing oil liquid pressure, a compensation structure is designed for a guider through the compensation framework, and the oil seal body is connected with the oil seal body through the compensation framework. The oil seal has sufficient compensation space, friction force between the oil seal and the piston rod is reduced to the maximum extent on the premise that sealing of the oil seal is guaranteed, motion starting of the piston rod is smoother, driving feeling of a vehicle is more comfortable, abrasion of the piston rod and the oil seal is greatly reduced due to the fact that the friction force is small, and the service life of the oil seal is prolonged. Therefore, the overall service life of the oil seal, the piston assembly and the single-cylinder shock absorber is greatly prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of single-tube shock absorbers, in particular to a force oil seal for a single-tube shock absorber and a single-tube shock absorber. Background Art

[0002] An oil seal is the customary name for a general seal. Simply put, it is the seal of lubricating oil and is a mechanical component used to seal grease. It isolates the components that need to be lubricated in the transmission components from the output components, so as to prevent the leakage of lubricating oil. A combined oil seal is composed of multiple oil seals combined by interference fit. Due to its multiple sealing properties, the combined oil seal is widely used in the sealing of shock absorbers.

[0003] In a single-tube shock absorber, the piston rod penetrates through the center of the oil seal, and high-pressure oil is stored inside the oil seal. The movement of the piston rod easily destroys the interference fit between the outer oil seal and the inner oil seal of the combined oil seal, thereby destroying the sealing performance of the combined oil seal and shortening the service life of the combined oil seal. At the same time, in order to maintain the sealing performance, the combined oil seal is designed to have a large enough radial force in its structure. However, the large radial force will increase the friction between the combined oil seal and the shaft, and the combined oil seal is easily damaged under long-term wear. Summary of the Utility Model

[0004] The purpose of the utility model is to provide an oil seal for a single-tube shock absorber and a single-tube shock absorber with small friction and long service life.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme: An oil seal for a single-tube shock absorber, the single-tube shock absorber includes a cylinder barrel, a piston assembly movably inserted into the cylinder barrel, and a guide arranged inside the upper end of the cylinder barrel. The piston assembly includes a piston rod and a piston connected to the lower end of the piston rod. Among them, the oil seal is arranged at the bottom end of the guide, the piston rod passes through the guide and the oil seal to be connected to the piston. The oil seal includes an oil seal body and a compensation skeleton arranged inside the oil seal body. The compensation skeleton has a pointed tip, and when the oil seal body bears the oil pressure, it can swing left and right around the pointed tip along with the compensation skeleton.

[0006] In one embodiment, the longitudinal section of the compensation skeleton is in an inverted V shape, and the vertex of the compensation skeleton forms the pointed tip.

[0007] In one embodiment, the compensation skeleton is integrally in a circular ring shape.

[0008] In one embodiment, the oil seal body includes an installation section and a sealing section. There is a transition step between the installation section and the sealing section. An installation groove for installing the oil seal is arranged on the inner side wall of the lower end of the guide.

[0009] In one embodiment, the compensation skeleton is embedded in the sealing section.

[0010] In one embodiment, the inner sidewall of the sealing section is gradually inclined inward from top to bottom so as to form an interference fit between the inner sidewall of the sealing section and the outer sidewall of the piston rod.

[0011] In one embodiment, the mounting section is in a circular ring shape.

[0012] In one embodiment, a buffer groove is provided on the lower end surface of the sealing section.

[0013] In one embodiment, there is a clearance fit between the inner sidewall of the mounting section and the outer sidewall of the piston rod; and / or, a compensation gap is provided between the outer sidewall of the sealing section and the mounting groove.

[0014] In the present utility model, a single-tube shock absorber is further disclosed, which includes a cylinder barrel, a piston assembly movably inserted into the cylinder barrel, a guide provided inside the upper end of the cylinder barrel, and an oil seal provided at the bottom end of the guide. Among them, the oil seal is the oil seal for the single-tube shock absorber in any of the above technical solutions.

[0015] After adopting the above technical solutions, the present utility model has the following advantages:

[0016] 1. In the present utility model, by adding a compensation skeleton inside the oil seal body and designing a compensation structure for the guide, the oil seal has sufficient compensation space. On the premise of ensuring the sealing of the oil seal, the friction between the oil seal and the piston rod is minimized to the greatest extent, which not only makes the movement start of the piston rod smoother, but also makes the driving and riding experience of the vehicle more comfortable. Also, due to the small friction, the wear between the piston rod and the oil seal is greatly reduced, thus greatly improving the overall service life of the oil seal, the piston assembly and the single-tube shock absorber.

[0017] 2. By setting the longitudinal section of the compensation skeleton in an inverted V shape, the vertex of the compensation skeleton forms the pointed point, and the side of the compensation skeleton close to the piston rod is shorter while the side close to the guide is longer. In this way, when the oil seal bears the oil pressure, the oil seal body can swing left and right around the V-shaped pointed point along with the compensation skeleton, so as to achieve the purpose of reducing the normal pressure between the oil seal and the piston rod, and further reducing the friction between the piston rod and the oil seal; specifically, when the piston rod reciprocates, the oil cavity pressure will increase or decrease, but the pressure direction received by the oil seal always points to the outside of the oil seal. As the oil pressure changes, the oil seal will swing inward or outward around the fulcrum of the V-shaped compensation skeleton, increasing or decreasing the pressure between the oil seal and the piston rod, ensuring that the normal pressure between the oil seal and the piston rod remains unchanged, and further keeping the friction unchanged.

[0018] 3. By setting the compensation skeleton as a whole in a circular ring shape, it is not only convenient for the processing and forming of the compensation skeleton, but also convenient for the shape matching between the compensation skeleton and the oil seal body, so as to facilitate the embedding of the compensation skeleton into the oil seal body to improve the production and processing efficiency of the two.

[0019] 4. By setting the oil seal body to include an installation section and a sealing section, and providing a transition step between the installation section and the sealing section, it is convenient for the transition connection between the installation section and the sealing section, and the connection is smooth, ensuring the integrity and smoothness of the integral structure. An installation groove for installing the oil seal is provided on the inner side wall at the lower end of the guide, which not only facilitates the installation of the oil seal, but also can well limit the oil seal, ensuring that the oil seal will not easily loosen, and thus ensuring the sealing effect of the oil seal.

[0020] 5. By embedding the compensation skeleton in the sealing section, the sealing effect of the sealing section can be well improved, while reducing the friction force at the sealing section, reducing wear, and greatly increasing the service life of the oil seal.

[0021] 6. By setting the inner side wall of the sealing section to be gradually inclined inward from top to bottom, the inner side wall of the sealing section can better form an interference fit with the outer side wall of the piston rod, so as to ensure good sealing effect of the oil seal.

[0022] 7. By setting the installation section to be circular ring-shaped, it is convenient for the cooperation with the installation groove, improving the production and assembly efficiency of the oil seal, not easily loosening, and the sealing performance can also be improved.

[0023] 8. By providing a buffer groove at the lower end of the sealing section, when the oil fluid impacts upward from below, the buffer groove can buffer the oil fluid, preventing the oil fluid from breaking through into the installation gap between the oil seal and the guide and causing the oil fluid to enter the guide and affecting the normal function effect of the guide.

[0024] 9. By setting the inner side wall of the installation section and the outer side wall of the piston rod to be in clearance fit, it is convenient for the oil seal body to swing left and right around the tip of the compensation skeleton, so as to automatically compensate the internal oil pressure of the shock absorber, reducing the friction force, and even keeping the friction force constant. It can also make the friction force of the shock absorber the same at different positions, and can automatically adjust the compensation amount of the contact between the oil seal and the piston rod according to the oil pressure, thus increasing the service life; and / or, a compensation gap can also be provided between the outer side wall of the sealing section and the installation groove. When the oil pressure increases, the oil seal fills the compensation gap of the guide with the deflection of the compensation skeleton, which is more conducive to the realization of the compensation function of the compensation skeleton; and, the cross-sectional shape of the compensation gap structure is not limited to a semi-circular groove, and can also be other grooves with cross-sectional shapes such as rectangular grooves, triangular grooves, and arc grooves.

[0025] 10. The present utility model also discloses a single-tube shock absorber. After adopting the oil seal in any of the above technical solutions, it can ensure that the friction force of the shock absorber remains unchanged at different stroke positions, thereby increasing the service life of the oil seal and the shock absorber. Brief Description of the Drawings

[0026] The present utility model will be further described below in conjunction with the accompanying drawings:

[0027] Figure 1 It is a three-dimensional structural schematic diagram of the single-tube shock absorber described in the present utility model.

[0028] Figure 2 It is the front view of the single-tube shock absorber described in the present utility model.

[0029] Figure 3 It is the sectional view of the single-tube shock absorber described in the present utility model.

[0030] Figure 4 It is Figure 3 the enlarged view of A in

[0031] Figure 5A It is the structural schematic diagram of the oil seal described in the present utility model.

[0032] Figure 5B It is the structural schematic diagram of the oil seal from another angle described in the present utility model.

[0033] Figure 5C It is the sectional view of the oil seal described in the present utility model.

[0034] Figure 6A It is the structural schematic diagram of the compensation skeleton described in the present utility model.

[0035] Figure 6B It is the structural schematic diagram of the compensation skeleton from another angle described in the present utility model.

[0036] Figure 6C It is the sectional view of the compensation skeleton described in the present utility model.

[0037] The names of the components marked in the figure are as follows:

[0038] 1. Cylinder barrel; 11. Cylinder body; 12. Dust cover; 13. Bottom cover of the cylinder barrel; 21. Piston rod; 22. Piston; 3. Guide; 31. Installation groove; 32. Compensation gap; 4. Oil seal; 41. Oil seal body; 411. Installation section; 412. Sealing section; 4121. Buffer groove; 413. Transition step; 42. Compensation skeleton; 421. Tip; 5. Baffle; 6. Buffer block; 7. Floating piston; 8. Suspension ring; 9. Bushing. Specific embodiments

[0039] In order to more clearly illustrate the overall concept of the present utility model, the following will be further described in detail by way of examples in conjunction with the accompanying drawings of the specification.

[0040] It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present utility model. However, the present utility model may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present utility model is not limited by the specific embodiments disclosed below.

[0041] In addition, in the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present utility model.

[0042] In the present utility model, unless otherwise clearly defined and limited, the terms "mounted", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected, or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. However, indicating a direct connection means that there is no connection relationship constructed through an excessive structure between the two connected main bodies, and they are only connected through the connection structure to form a whole. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0043] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0044] Such as Figures 1 to 6CAs shown in the figure, the utility model provides a single-tube shock absorber, which comprises a cylinder barrel 1, a piston assembly movably inserted into the cylinder barrel 1, a guide 3 arranged inside the upper end of the cylinder barrel 1, and an oil seal 4 arranged at the bottom end of the guide 3. The piston assembly includes a piston rod 21 and a piston 22 connected to the lower end of the piston rod 21. The cylinder barrel 1 includes a cylinder body 11, a dust cover 12 arranged at the top end of the cylinder body 11, and a cylinder bottom cover 13 arranged at the bottom of the cylinder body 11. One end of the piston rod 21 passes through the top end of the dust cover 12 and the central hole of the guide 3 to be connected with the piston 22. A sealing ring is arranged between the dust cover 12 and the piston rod 21. The guide 3 is fixed inside the cylinder body 11 through a snap ring. A lifting ring 8 is connected to the bottom of the cylinder bottom cover 13, and a bushing 9 is nested inside the lifting ring 8. In this way, the overall structure of the shock absorber is simple, which is convenient for production and assembly.

[0045] In this embodiment, the oil seal 4 is arranged at the bottom end of the guide 3. The piston rod 21 passes through the guide 3 and the oil seal 4 to be connected with the piston 22. The oil seal 4 includes an oil seal body 41 and a compensation skeleton 42 arranged inside the oil seal body 41. The compensation skeleton 42 has a pointed tip 421. When the oil seal body 41 bears the oil pressure, it can swing left and right around the pointed tip 421 along with the compensation skeleton 42. By adding a compensation skeleton inside the oil seal body and designing a compensation structure for the guide, sufficient compensation space is provided for the oil seal. On the premise of ensuring the sealing of the oil seal, the friction force between the oil seal and the piston rod is minimized, which not only makes the movement start of the piston rod smoother, but also makes the driving and riding experience of the vehicle more comfortable. Also, due to the small friction force, the wear between the piston rod and the oil seal is greatly reduced, thus greatly improving the service life of the oil seal, the piston assembly and the single-tube shock absorber as a whole.

[0046] In some embodiments, the longitudinal section of the compensation skeleton 42 is in an inverted V shape, and the vertex of the compensation skeleton 42 forms the pointed tip 421. By setting the longitudinal section of the compensation skeleton in an inverted V shape, the vertex of the compensation skeleton forms the pointed tip, and the side of the compensation skeleton close to the piston rod is shorter, while the side close to the guide is longer. In this way, when the oil seal bears the oil pressure, the oil seal body can swing left and right around the V-shaped pointed tip along with the compensation skeleton, so as to achieve the purpose of reducing the normal pressure between the oil seal and the piston rod, and further reducing the friction force between the piston rod and the oil seal. Specifically, when the piston rod reciprocates, the oil chamber pressure will increase or decrease, but the pressure direction received by the oil seal always points to the outside of the oil seal. As the oil pressure changes, the oil seal will swing inwards or outwards around the V-shaped compensation skeleton fulcrum, increasing or decreasing the pressure between the oil seal and the piston rod, ensuring that the normal pressure between the oil seal and the piston rod remains unchanged, and further keeping the friction force unchanged.

[0047] In some embodiments, the compensation skeleton 42 is integrally annular, which not only facilitates the processing and forming of the compensation skeleton, but also facilitates the shape matching between the compensation skeleton and the oil seal body, thereby facilitating the embedding of the compensation skeleton into the oil seal body to improve the production and processing efficiency of both; and, the oil seal body 41 is made of rubber material, and the oil seal body 41 includes an installation section 411 and a sealing section 412. A transition step 413 is provided between the installation section 411 and the sealing section 412, which facilitates the transition connection between the installation section and the sealing section, and the connection is smooth, ensuring the integrity and smoothness of the integral structure. The inner side wall of the lower end of the guide 3 is provided with an installation groove 31 for installing the oil seal 4, which not only facilitates the installation of the oil seal, but also can well limit the oil seal to ensure that the oil seal will not easily become loose, thereby ensuring the sealing effect of the oil seal.

[0048] And, the compensation skeleton 42 is embedded in the sealing section 412, specifically by secondary injection molding, that is, first fabricate the compensation skeleton 42 and place it in the mold for forming the oil seal body 41, and inject the rubber material for forming the oil seal body 41 into the mold to finally form the oil seal 4. The oil seal formed in this way can well improve the sealing effect of the sealing section, at the same time reduce the friction force at the sealing section, reduce wear, and greatly improve the service life of the oil seal.

[0049] In some embodiments, the inner side wall of the sealing section 412 is gradually inclined inward from top to bottom so that an interference fit is formed between the inner side wall of the sealing section 412 and the outer side wall of the piston rod 21, so that the inner side wall of the sealing section can better form an interference fit with the outer side wall of the piston rod to ensure good sealing effect of the oil seal. And the installation section 411 is circular and annular, which is convenient for the cooperation with the installation groove, improves the production and assembly efficiency of the oil seal, is not easy to become loose, and the sealing performance can also be improved.

[0050] In some embodiments, a buffer groove 4121 is provided on the lower end surface of the sealing section 412. The buffer groove 4121 is annular and is arranged to match the outer contour shape of the sealing section 412. In this way, when the oil fluid impacts from the bottom upwards, the buffer groove can buffer the oil fluid to prevent the oil fluid from breaking through into the installation gap between the oil seal and the guide and causing the oil fluid to enter the guide and affect the normal function effect of the guide. Of course, it can be understood that multiple buffer grooves 4121 can also be provided, and the multiple buffer grooves 4121 are arranged along the circumferential direction of the sealing section 412.

[0051] In some embodiments, a clearance fit may be provided between the inner sidewall of the installation section 411 and the outer sidewall of the piston rod 21. This facilitates the left and right swinging of the oil seal body around the tip of the compensation skeleton, thereby automatically compensating for the internal oil pressure of the shock absorber, reducing the frictional force, and even keeping the frictional force constant. It can also make the frictional force of the shock absorber consistent at different positions, and automatically adjust the compensation amount of the contact between the oil seal and the piston rod according to the oil pressure, thereby increasing the service life; and / or, a compensation gap 32 may be provided between the outer sidewall of the sealing section 412 and the installation groove 31. When the oil pressure increases, the oil seal fills the compensation gap of the guide with the deflection of the compensation skeleton, which is more conducive to the realization of the compensation function of the compensation skeleton; and, the cross-sectional shape of the compensation gap structure is not limited to a semi-circular groove, and may also be other grooves with any cross-sectional shape such as a rectangular groove, a triangular groove, an arc groove, etc.

[0052] In some embodiments, a baffle 5 may be provided at the lower end of the oil seal 4, and a buffer block 6 may be provided at the lower end of the baffle 5. In this way, when the piston rod moves, it drives the magnetorheological fluid to move, and the buffer block can effectively block the impact force of the buffer magnetorheological fluid, thereby better preventing the magnetorheological fluid from entering the hollow cavity of the guide.

[0053] In some embodiments, the single-tube shock absorber further includes a floating piston 7. The floating piston 7 is installed in the cylinder barrel 1 and is located below the piston 22, so as to better reduce wear and improve efficiency. A first cavity is formed between the guide 3 and the floating piston 22, and the first cavity is filled with magnetorheological fluid. The piston 22 reciprocates in the first cavity, so that a magnetic induction change occurs between the piston 22 and the magnetorheological fluid when the piston 22 moves in the first cavity, thereby changing the damping force during compression and recovery to achieve a shock absorption effect. A second cavity is formed between the floating piston 7 and the bottom of the cylinder barrel 1 (i.e., the cylinder bottom cover 13), and a high-pressure gas (such as nitrogen) is filled in the second cavity to enhance the shock absorption effect of the shock absorber.

[0054] In addition to the above preferred embodiments, the technical solutions protected by the present invention are not limited to the above embodiments. It should be noted that the combination of the technical solutions of any one embodiment with the technical solutions of one or more other embodiments is within the protection scope of the present invention. Although the present invention has been described in detail with general descriptions and specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope required to be protected by the present invention.

Claims

1. An oil seal for a mono-tube shock absorber. The mono-tube shock absorber includes a cylinder barrel, a piston assembly movably inserted into the cylinder barrel, and a guide installed inside the upper end of the cylinder barrel. The piston assembly includes a piston rod and a piston connected to the lower end of the piston rod. It is characterized in that, The oil seal is installed at the bottom end of the guide. The piston rod passes through the guide and the oil seal to be connected with the piston. The oil seal includes an oil seal body and a compensation skeleton arranged inside the oil seal body. The compensation skeleton has a pointed tip, and when the oil seal body bears the oil pressure, it can swing left and right around the pointed tip along with the compensation skeleton.

2. The oil seal for a single-tube shock absorber according to claim 1, wherein, The longitudinal section of the compensation skeleton is in an inverted V shape, and the vertex of the compensation skeleton forms the pointed tip.

3. The oil seal for a single-tube shock absorber according to claim 1, characterized in that, The compensation skeleton is integrally in a circular ring shape.

4. The oil seal for a single-tube shock absorber according to claim 1, wherein The oil seal body includes an installation section and a sealing section. A transition step is provided between the installation section and the sealing section. An installation groove for installing the oil seal is provided on the inner side wall of the lower end of the guide.

5. The oil seal for a single-tube shock absorber according to claim 4, wherein The compensation skeleton is embedded in the sealing section.

6. The oil seal for a single-tube shock absorber according to claim 4, wherein, The inner side wall of the sealing section is gradually inclined inward from top to bottom so that an interference fit is formed between the inner side wall of the sealing section and the outer side wall of the piston rod.

7. The oil seal for a single-tube shock absorber according to claim 4, characterized in that, The installation section is in a circular ring shape.

8. The oil seal for a single-tube shock absorber according to claim 4, characterized in that, A buffer groove is provided on the lower end face of the sealing section.

9. The oil seal for a single-tube shock absorber according to claim 4, wherein, A clearance fit is provided between the inner side wall of the installation section and the outer side wall of the piston rod; and / or, a compensation clearance is provided between the outer side wall of the sealing section and the installation groove.

10. A single-tube shock absorber, comprising a cylinder barrel, a piston assembly movably inserted into the cylinder barrel, a guide arranged inside the upper end of the cylinder barrel, and an oil seal arranged at the bottom end of the guide, characterized in that, The oil seal is the oil seal for a single-tube shock absorber as described in any one of claims 1 to 9.

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