U-shaped frameless oil seal with protection function

Abstract

The utility model relates to the technical field of oil seals, in particular to a U-shaped frameless oil seal with a protection function, which comprises an outer ring, a sealing lip is fixedly connected in the outer ring, the sealing lip comprises a waist part, a plurality of protection bosses are fixedly connected on the inner side of the waist part, a spiral flow guide groove is arranged on the outer side of the outer ring, and the spiral flow guide groove is communicated with the outer ring. A plurality of through holes are formed between the spiral flow guide groove and the waist portion, a medium in the spiral flow guide groove enters a gap between the sealing lip and a rotating shaft through the through holes under the action of centrifugal force, a layer of lubricating film is formed, the cleaning and lubricating effects are achieved, friction and abrasion between the sealing lip and the shaft are reduced, and the service life of the sealing lip is prolonged. The protection boss blocks most impurities in a medium entering the gap between the sealing lip and the rotating shaft, the protection performance of the oil seal is further improved, the surface of the shaft is protected against damage, and the running reliability of equipment is improved.

Description

Technical Field

[0001] This utility model relates to the field of oil seal technology, specifically to a U-shaped frameless oil seal with protective function. Background Technology

[0002] U-shaped frameless oil seals are one of the core components in the field of mechanical seals, widely used in rotary shaft sealing applications in automobiles, industrial equipment, aerospace, and rail transportation. Their core advantages lie in their compact structure, convenient installation, and low cost, making them particularly suitable for space-constrained or lightweight design requirements. However, with the increasing automation of industry and the development of mechanical equipment towards higher speeds, higher pressures, and greater intelligence, the performance bottlenecks of traditional U-shaped frameless oil seals are becoming increasingly apparent.

[0003] There are many existing technologies for oil seals, such as:

[0004] Chinese Patent (Application No.: CN202021931139.5) discloses a high-low pressure bidirectional oil seal structure, including an oil seal skeleton. A spacer ring is fixed in the middle of the oil seal skeleton, which divides the inner cavity of the oil seal skeleton into a low-pressure chamber and a high-pressure chamber. An oil seal body is provided at one end of the oil seal skeleton. The oil seal body includes an oil seal pressure plate. A connecting part is integrally formed in the middle of the bottom surface of the oil seal pressure plate. A slot for inserting the spacer ring is opened in the center of the bottom surface of the connecting part. A low-pressure oil seal pressing part is integrally formed on one side of the bottom surface of the connecting part. A high-pressure oil seal pressing part is integrally formed on the other side of the bottom surface of the connecting part. U-shaped slots are opened on the top surfaces of the low-pressure oil seal pressing part and the high-pressure oil seal pressing part. A positioning spring is engaged in the U-shaped slot. The structure of this utility model is reasonable. Its low-pressure oil seal pressure part and high-pressure oil seal pressure part are integrally formed, which helps to reduce processing costs. At the same time, it realizes oil seals at both low-pressure and high-pressure ends, which is stable and reliable in use, highly applicable and practical.

[0005] Traditional U-shaped frameless oil seals are usually made of a single rubber material and rely on the interference fit between the sealing lip and the surface of the rotating shaft to achieve a seal. The sealing lip is in direct contact with the rotating shaft. During long-term high-speed rotation, it is prone to wear due to friction, which leads to thinning of the sealing lip and reduced sealing performance. Moreover, there is a lack of effective protection measures. When the working medium contains particulate impurities, the impurities can easily enter the gap between the sealing lip and the shaft, aggravating wear and even scratching the shaft surface. Utility Model Content

[0006] This utility model addresses the technical problems existing in the prior art by providing a U-shaped frameless oil seal with protective function. It solves the problems that traditional oil seals are prone to wear due to friction during long-term use, resulting in thinning of the sealing lip and reduced sealing performance. It also addresses the problem that traditional oil seals have insufficient protective capabilities, allowing impurities to easily enter the gap between the sealing lip and the shaft, exacerbating wear and even scratching the shaft surface.

[0007] To achieve the above objectives, this utility model provides a U-shaped frameless oil seal with protective function, comprising an outer ring, wherein a sealing lip is fixedly connected inside the outer ring, wherein: the sealing lip includes a waist, and a plurality of protective protrusions are fixedly connected to the inner side of the waist; a spiral guide groove is provided on the outer side of the outer ring, and a plurality of through holes are provided between the spiral guide groove and the waist; the medium in the spiral guide groove, under the action of centrifugal force, enters the gap between the sealing lip and the rotating shaft through the through holes, forming a lubricating film; the protective protrusions block most of the impurities in the medium entering the gap between the sealing lip and the rotating shaft.

[0008] The beneficial effects of this utility model are:

[0009] 1. When the rotating shaft rotates, the spiral guide groove generates centrifugal force, which throws out particulate impurities attached to the surface of the oil seal. At the same time, the medium in the spiral guide groove, under the action of centrifugal force, enters the gap between the waist, lip and shaft through the through hole, forming a lubricating film, which plays a role in cleaning and lubrication, reducing friction and wear between the sealing lip and the shaft, and extending the service life of the oil seal.

[0010] 2. During the sealing process, when the medium contains particulate impurities, the protective boss can block most of the impurities from entering the lip area, further improving the protective performance of the oil seal, protecting the shaft surface from damage, and improving the reliability of equipment operation.

[0011] Based on the above technical solution, the present invention can be further improved as follows.

[0012] Preferably, the top of the waist section is provided with a lip, and the lower end of the inner side of the waist section is fixedly connected with a dustproof lip.

[0013] The beneficial effect of adopting the above-mentioned further solution is that the dust lip and the protective protrusion work together to form a dual protection system of "coarse filtration + fine blocking". The dust lip first intercepts larger particulate impurities, and the protective protrusion then filters fine particles, reducing the wear of impurities on the lip opening.

[0014] Preferably, a U-shaped cavity is formed between the outer ring and the sealing lip, with a groove provided on one side of the U-shaped cavity and a spring groove provided on the other side of the U-shaped cavity.

[0015] The advantages of adopting the above-mentioned further solution are that the groove design facilitates rapid demolding during oil seal production, and the addition of a helical spring inside the spring groove allows for compensation of lip wear through elastic force, maintaining long-term sealing pressure.

[0016] Preferably, both the outer ring and the sealing lip are provided with composite components. The composite components include a sealing layer, a buffer protection layer, and a support layer. The sealing layer is located in the innermost layer of the structure and is made of high-performance fluororubber material. The buffer protection layer is located in the middle layer of the structure and is made of polyurethane elastomer material. The support layer is located in the outermost layer of the structure and is made of fiber-reinforced rubber material.

[0017] The beneficial effects of adopting the above-mentioned further solutions are that the buffer protective layer effectively reduces the friction and wear between the sealing lip and the rotating shaft, extends the service life of the oil seal, and the sealing layer and support layer enable the oil seal to work stably under harsh conditions such as high temperature, high pressure, and strong corrosion.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] By setting a spiral guide groove on the outer side of the outer ring, and connecting the spiral guide groove with the sealing lip through several through holes, when the rotating shaft rotates, the spiral guide groove generates centrifugal force, which throws out particulate impurities attached to the oil seal surface. At the same time, the medium in the spiral guide groove, under the action of centrifugal force, enters the gap between the waist, lip and shaft through the through holes, forming a lubricating film, which plays a role in cleaning and lubrication, reducing friction and wear between the sealing lip and shaft, and extending the service life of the oil seal. In addition, a small gap is left between the protective boss and the shaft. When the medium contains particulate impurities, the protective boss can block most of the impurities from entering the lip area, further improving the protective performance of the oil seal, protecting the shaft surface from damage, and improving the reliability of equipment operation. Attached Figure Description

[0020] Figure 1 This is an isometric view of one side of the overall structure of this utility model;

[0021] Figure 2 This is an isometric view of the other side of the overall structure of this utility model;

[0022] Figure 3 This is a front cross-sectional view of the present invention.

[0023] Figure 4 This is a schematic diagram of the material structure of the outer ring and sealing lip of this utility model.

[0024] The meanings of the labels in the diagram are as follows:

[0025] 1. Outer ring;

[0026] 2. Sealing lip; 21. Waist; 22. Lip opening; 23. Protective protrusion; 24. Dustproof lip;

[0027] 3. Spiral guide groove; 31. Through hole;

[0028] 4. U-shaped cavity; 41. Groove; 42. Spring groove;

[0029] 5. Composite component; 51. Sealing layer; 52. Buffer protection layer; 53. Support layer. Detailed Implementation

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

[0031] Please see Figures 1-4 As shown, considering that traditional oil seals are prone to wear due to friction during long-term use, resulting in thinning of the sealing lip and reduced sealing performance, and that traditional oil seals have insufficient protective capabilities, impurities can easily enter the gap between the sealing lip and the shaft, aggravating wear and even scratching the shaft surface, this embodiment provides a U-shaped frameless oil seal with protective function, including an outer ring 1, with a sealing lip 2 fixedly connected inside the outer ring 1, wherein: the sealing lip 2 includes a waist 21, and several protective bosses 23 are fixedly connected to the inner side of the waist 21, with a small gap between the protective bosses 23 and the shaft, and a spiral guide groove 3 is provided on the outer side of the outer ring 1, with several through holes 31 provided between the spiral guide groove 3 and the waist 21, the medium in the spiral guide groove 3 enters the gap between the sealing lip 2 and the rotating shaft through the through holes 31 under the action of centrifugal force, forming a lubricating film, reducing friction and wear between the sealing lip 2 and the shaft, and the protective bosses 23 block most of the impurities in the medium entering the gap between the sealing lip 2 and the rotating shaft, avoiding damage to the shaft by impurities.

[0032] In summary, the improvement of this embodiment lies in:

[0033] The spiral guide groove 3 on the outer side of the outer ring 1, combined with the through hole 31, uses centrifugal force to throw some impurities in the medium away from the sealing area, while guiding the clean medium into the gap between the sealing lip 2 and the shaft to form a lubricating film and reduce wear. A protective boss 23 is set on the inner side of the waist 21 of the sealing lip 2. The boss structure forms a physical barrier against impurities in the medium, reducing the entry of impurities into the sealing core area (the contact point between the lip 22 and the shaft), further improving the protective performance of the oil seal, protecting the shaft surface from damage, and improving the reliability of equipment operation.

[0034] Based on the above, other structures also need to be disclosed in detail, such as:

[0035] To ensure the sealing performance of the oil seal, a lip 22 is provided at the top of the waist section 21, and a dustproof lip 24 is fixedly connected to the lower inner end of the waist section 21. The lip 22, located at the top of the waist section 21, is a key sealing part that directly contacts the rotating shaft. Through an interference fit, radial contact pressure is formed to prevent media such as lubricating oil and hydraulic oil from leaking outward. The dustproof lip 24 faces outward and forms a non-contact sealing gap or slight contact with the shaft surface to prevent external dust, mud, water vapor, and other impurities from entering the oil seal. Together with the protective boss 23, it forms a dual protection system of "coarse filtration + fine blocking". The dustproof lip 24 first intercepts larger particles of impurities, and the protective boss 23 then filters fine particles, reducing the wear of impurities on the lip 22.

[0036] Considering that oil seals are prone to tearing or deformation when separated from the mold during production, which reduces the yield of oil seal production, a U-shaped cavity 4 is formed between the outer ring 1 and the sealing lip 2. A groove 41 is provided on one side of the U-shaped cavity 4. The groove 41 cooperates with the convex ring in the inner mold, so that when the inner mold moves upward, the oil seal can be directly "carried out" through the convex ring, reducing frictional resistance and the risk of adhesion, and reducing the scrap rate of oil seal production.

[0037] To improve the sealing performance of the sealing lip 2, a spring groove 42 is provided on the other side of the U-shaped cavity 4. A helical spring is installed inside the spring groove 42 to compensate for the wear of the lip 22 through elastic force, maintain long-term sealing pressure, and avoid leakage caused by the aging of the lip 22.

[0038] Considering that traditional oil seals are mostly made of a single material and are prone to aging and wear in high-speed, high-temperature, and corrosive media, affecting their service life, composite components 5 are set inside both the outer ring 1 and the sealing lip 2. Composite components 5 include a sealing layer 51, a buffer protection layer 52, and a support layer 53. The sealing layer 51 is located in the innermost layer of the structure and is made of high-performance fluororubber material, which has excellent oil resistance, temperature resistance, and chemical corrosion resistance, and can maintain good sealing performance in various complex media environments. The buffer protection layer 52 is located in the middle layer of the structure and is made of polyurethane elastomer material, which has good elasticity and buffering properties. When there are particulate impurities between the sealing lip 2 and the rotating shaft, the buffer protection layer 52 can buffer the impurities and reduce damage to the sealing lip 2 and shaft surface. The support layer 53 is located in the outermost layer of the structure and is made of fiber-reinforced rubber material, enhancing the overall structural strength and stability of the oil seal. Under high-temperature and high-pressure conditions, the support layer 53 can effectively prevent oil seal deformation and ensure that the sealing layer 51 and the buffer protection layer 52 function properly.

[0039] In summary, the working principle of this solution is as follows:

[0040] During operation, the oil seal is installed between the rotating shaft and the equipment cavity. The outer ring 1 is fixed to the cavity, and the inner side of the sealing lip 2 contacts the shaft surface. The sealing lip includes a waist 21, a lip 22, a protective boss 23, and a dustproof lip 24. The lip 22 forms the main sealing surface through an interference fit with the shaft, directly preventing media leakage. The spring groove 42 is located in the U-shaped cavity 4. The continuous elastic force of the spring in the spring groove 42 compensates for the wear of the lip 22, maintains the contact pressure, and ensures long-term sealing reliability. The design of 3 and 31 achieves self-lubrication. When the shaft rotates, the guide groove generates centrifugal force, throwing the external medium (such as lubricating oil) into the groove. The medium flows into the gap between the sealing lip 2 and the shaft through the through hole 31, forming a lubricating film, reducing friction and wear, and reducing heat generation. The protective boss 25 and the dustproof lip 24 form a dual protection system. The protective boss is located on the inner side of the waist and blocks particulate impurities in the medium through the annular protrusion; the dustproof lip is located at the lower end of the waist and prevents external dust and moisture from entering, reducing the wear of impurities on the sealing lip. The elastic deformation of the U-shaped cavity 4 can adapt to shaft vibration and eccentricity, ensuring the oil seal maintains structural integrity under harsh conditions such as high pressure and high temperature. The composite component 5 consists of a sealing layer 51, a buffer protection layer 52, and a support layer 53. The sealing layer 51 is made of fluororubber, which is in direct contact with the medium and provides excellent oil and corrosion resistance; the buffer protection layer 52 uses polyurethane to absorb vibration and shock; and the support layer 53 uses fiber-reinforced rubber to enhance the overall strength, together ensuring the stable operation of the oil seal under complex conditions.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A U-shaped frameless oil seal with protective function, comprising an outer ring (1), characterized in that: The outer ring (1) is fixedly connected to a sealing lip (2), wherein: the sealing lip (2) includes a waist (21), and a number of protective protrusions (23) are fixedly connected to the inner side of the waist (21). A spiral guide groove (3) is provided on the outer side of the outer ring (1), and a number of through holes (31) are provided between the spiral guide groove (3) and the waist (21). Under the action of centrifugal force, the medium in the spiral guide groove (3) enters the gap between the sealing lip (2) and the rotating shaft through the through holes (31) to form a lubricating film. The protective protrusions (23) block most of the impurities in the medium entering the gap between the sealing lip (2) and the rotating shaft.

2. The U-shaped frameless oil seal with protective function according to claim 1, characterized in that: The waist (21) is provided with a lip (22) at the top, and a dustproof lip (24) is fixedly connected to the lower end of the inner side of the waist (21).

3. The U-shaped frameless oil seal with protective function according to claim 1, characterized in that: A U-shaped cavity (4) is formed between the outer ring (1) and the sealing lip (2), and a groove (41) is provided on one side of the inside of the U-shaped cavity (4).

4. A U-shaped frameless oil seal with protective function according to claim 3, characterized in that: A spring groove (42) is provided on the other side of the U-shaped cavity (4).

5. A U-shaped frameless oil seal with protective function according to claim 1, characterized in that: The outer ring (1) and the sealing lip (2) are both provided with a composite component (5), which includes a sealing layer (51), a buffer protection layer (52), and a support layer (53).

6. A U-shaped frameless oil seal with protective function according to claim 5, characterized in that: The sealing layer (51) is located in the innermost layer of the structure and is made of high-performance fluororubber material. The buffer protection layer (52) is located in the middle layer of the structure and is made of polyurethane elastomer material. The support layer (53) is located in the outermost layer of the structure and is made of fiber-reinforced rubber material.

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