Novel shaft seal

Abstract

The invention belongs to the technical field of shaft seals, and particularly relates to a novel shaft seal which comprises a main framework, an auxiliary framework is arranged on the inner wall of the main framework, a partition frame is installed on the auxiliary framework, a first sealing lip is installed between the auxiliary framework and the partition frame, and a spring is installed in an inner cavity of the first sealing lip. A second sealing lip is installed between the partition frame and the main framework, and a sealing gasket is installed between the second sealing lip and the main framework. According to the shaft seal, the overall structural design is optimized, and a composite sealing structure that the double sealing lips are matched with spring pre-tightening, integrated framework supporting and auxiliary sealing gaskets is adopted, so that multiple sealing protection is achieved, and the sealing reliability is improved; meanwhile, the structural forms of the sealing lips and the framework are optimized, the attaching precision and stability of the sealing lips are guaranteed, the sealing redundancy stability of the shaft seal is improved, frictional wear is reduced, high-temperature shaping of the shaft seal is prevented, the sealing performance of the shaft seal is prevented from being affected, the service life is prolonged, and the shaft end sealing device is suitable for shaft end sealing scenes under various complex working conditions.

Description

Technical Field

[0001] This invention relates to the field of shaft seal technology, specifically a novel shaft seal. Background Technology

[0002] Traditional skeleton oil seals can only operate under lubrication conditions; they are prone to wear and aging when there is no lubrication or only a small amount of lubrication. Traditional PTFE shaft seals are also susceptible to unstable redundancy due to temperature changes, leading to seal deformation, media leakage, and disruption of equipment operation. Furthermore, the design of traditional oil seals is often flawed, with a small lip-shaft contact area and high requirements for shaft runout. Under long-term equipment vibration, high temperatures, and alternating loads, this can easily result in uneven preload distribution of the sealing lip, decreased sealing surface fit accuracy, and coaxiality deviations, further accelerating lip wear and shortening the oil seal's service life.

[0003] In view of the shortcomings of the existing technology, there is an urgent need to develop a new type of shaft seal with reasonable structural design, reliable sealing performance, strong load-bearing capacity and long service life, so as to solve the problems of unstable sealing redundancy, easy aging without lubrication, rapid wear of sealing lip and easy leakage of existing shaft seals, and meet the sealing needs of various mechanical equipment under complex working conditions. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the current shaft seal, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the defects of existing shaft seals, such as poor sealing performance, easy wear of sealing lips, and short service life, and to provide a new type of shaft seal. This shaft seal, through optimized overall structural design, adopts a composite sealing structure with double sealing lips, spring preload, integrated skeleton support, and auxiliary sealing gaskets, achieving multiple sealing protections and improving sealing reliability. Simultaneously, it optimizes the structural morphology of the sealing lips and skeleton, ensuring the sealing lip fitting accuracy and stability, increasing the stability of the shaft seal's sealing redundancy, reducing friction and wear, preventing high-temperature deformation of the shaft seal that could affect its sealing performance, and extending its service life. It is suitable for shaft end sealing scenarios under various complex working conditions.

[0007] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: A novel shaft seal includes a main frame; A secondary frame is provided on the inner wall of the main frame, a partition is installed on the secondary frame, a first sealing lip is installed between the secondary frame and the partition, a spring is installed in the inner cavity of the first sealing lip, a second sealing lip is installed between the partition and the main frame, and a sealing gasket is installed between the second sealing lip and the main frame.

[0008] In a preferred embodiment of the novel shaft seal described in this invention, the main frame and the secondary frame have L-shaped cross-sections, and the secondary frame and the main frame are integrally formed.

[0009] In a preferred embodiment of the novel shaft seal described in this invention, the spacer is an annular structure, and the first sealing lip and the second sealing lip are located at the bottom and top of the spacer, respectively.

[0010] In a preferred embodiment of the novel shaft seal described in this invention, a hollow cavity is provided in the middle of the first sealing lip, and the spring is located within the hollow cavity.

[0011] In a preferred embodiment of the novel shaft seal described in this invention, the sealing gasket has an annular structure and is fixedly connected to the second sealing lip and the main frame.

[0012] In a preferred embodiment of the novel shaft seal described in this invention, the inner sides of the first and second sealing lips are bent downwards, and the bends are arc-shaped.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. Compared to traditional rubber shaft seals, it offers superior sealing performance: Utilizing a composite sealing structure of a first sealing lip, a second sealing lip, and a sealing gasket, it forms a double sealing barrier. Combined with spring preload, this effectively prevents media leakage, significantly improving sealing reliability. Even with slight wear or damage to the first sealing lip, the second sealing lip can still provide a seal, preventing seal failure and significantly increasing the sealing redundancy of the shaft seal. It is suitable for high-pressure and leak-prone operating conditions.

[0014] 2. Compared with other seals, it has a longer service life: The main frame and the secondary frame adopt an integrated L-shaped structure design, which has high rigidity, good coaxiality, and no assembly gap. It can effectively resist the effects of working condition vibration, pressure and temperature changes, and avoid frame deformation or loosening of sealing components; the spring has elastic compensation capability, which can compensate for the wear of the sealing lip and extend the service life of the sealing lip.

[0015] 3. Compared with external spring PTFE shaft seals, friction is lower: Due to the built-in spring, there is no need to increase the thickness of the PTFE sheet, and the arc-shaped bending structure on the inner side of the sealing lip reduces the contact friction area with the rotating shaft, thus reducing frictional resistance. At the same time, the annular sealing groove on the inner side of the first sealing lip can form a lubricating oil film, further reducing friction and wear, reducing equipment operating energy consumption, and preventing the sealing lip from aging due to overheating. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a top view of the structure of the present invention; Figure 3 This is a cross-sectional structural diagram of the present invention.

[0017] In the diagram: 100 main frame, 110 secondary frame, 120 spacer, 130 first sealing lip, 140 second sealing lip. Lip sealing, 150 spring, 160 sealing gasket. Detailed Implementation

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0019] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0020] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0022] This invention provides the following technical solution: a novel shaft seal, which, compared to traditional rubber shaft seals, exhibits superior sealing performance during use. It employs a composite sealing structure consisting of a first sealing lip, a second sealing lip, and a sealing gasket, forming a double sealing barrier. Combined with spring preload, this effectively prevents media leakage, significantly improving sealing reliability. Even if the first sealing lip experiences slight wear or damage, the second sealing lip can still function as a seal, preventing seal failure and significantly enhancing the sealing redundancy of the shaft seal. This makes it suitable for high-pressure, leak-prone operating conditions.

[0023] Compared to other seals, this seal has a longer service life: the main and secondary skeletons adopt an integrated L-shaped structure design, which is rigid, has good coaxiality, and no assembly gaps. It can effectively resist the effects of vibration, pressure and temperature changes in the working conditions, and avoid skeleton deformation or loosening of sealing components; the spring has elastic compensation capability, which can compensate for the wear of the sealing lip and extend the service life of the sealing lip.

[0024] Compared to external spring PTFE shaft seals, friction is lower: due to the built-in spring, there is no need to increase the thickness of the PTFE sheet, and the arc-shaped bending structure on the inner side of the sealing lip reduces the contact friction area with the rotating shaft, thus reducing frictional resistance. At the same time, the annular sealing groove on the inner side of the first sealing lip can form a lubricating oil film, further reducing friction and wear, reducing equipment operating energy consumption, and preventing the sealing lip from aging due to overheating.

[0025] Example 1: A novel shaft seal suitable for general hydraulic equipment This embodiment provides a novel shaft seal suitable for ordinary hydraulic equipment. The hydraulic equipment has a working pressure of 0.5-2MPa, a working temperature of -20℃ to 80℃, uses 46# anti-wear hydraulic oil as the medium, and has a rotating shaft speed of 500-2000r / min.

[0026] 1. Component structure and material selection: The main frame 100 and the secondary frame 110 are made of carbon steel and are formed into an integrated L-shaped structure by stamping. The main frame 100 has an outer diameter of 80mm, an inner diameter of 60mm, and an axial length of 12mm. The secondary frame 110 is located on the upper part of the inner wall of the main frame 100, with a radial length of 78mm and an axial length of 5mm. The inner wall of the secondary frame 110 is provided with an annular positioning groove with a depth of 1mm.

[0027] The partition 120 is made of 45# steel in a ring structure with an outer diameter of 78mm, an inner diameter of 65mm, and a thickness of 3mm. The outer circular surface of the partition 120 is provided with a flange with a thickness of 1mm, which is installed in conjunction with the positioning groove of the sub-frame 110 with a fitting clearance of 0.05mm.

[0028] The first sealing lip 130 and the second sealing lip 140 are made of modified polytetrafluoroethylene with a Shore hardness of 60-70 degrees. The inner side of the sealing lip is bent downward at a bending angle of 30° and the radius of the arc at the bend is 2mm. The first sealing lip 130 has a hollow cavity in the middle with a diameter of 58mm and a length of 8mm. Two annular sealing grooves are provided on the inner side of the cavity, with a groove depth of 0.2mm and a groove width of 0.5mm. The structure of the second sealing lip 140 is the same as that of the first sealing lip 130, except that the cavity size is adapted to the installation position of the spacer 120.

[0029] The spring 150 is made of 304 stainless steel wire with a diameter of 1.2mm. It has a ring structure with an inner diameter of 76mm, an outer diameter of 79mm, 8 coils, and a spring force of 5-8N. After the spring 150 is installed into the cavity of the first sealing lip 130, it is fixed by a 0.3mm thick PTFE retaining ring, which is bonded to the cavity.

[0030] The sealing gasket 160 is made of nitrile rubber in a ring structure with an outer diameter of 78 mm, an inner diameter of 65 mm, and a thickness of 1 mm. It is fixed in the gap between the second sealing lip 140 and the main skeleton 100 by strong extrusion.

[0031] 2. Assembly process: First, the sealing gasket 160 is embedded into the sealing groove of the main frame 100; then the second sealing lip 140 is installed between the spacer 120 and the sealing gasket 160; then the spacer 120 is placed on the second sealing lip 140; next, the spring 150 is installed into the hollow cavity of the first sealing lip 130; the position of the spring 150 is adjusted to be centered; then the first sealing lip 130 is installed between the sub-frame 110 and the spacer 120; so that the first sealing lip 130 and the spacer 120 on the inner wall of the sub-frame 110 are tightly fitted; finally, the inner frame 110 is embedded into the main frame 100; all components are pressed tightly together by the spinning sealing technology; the overall assembly of the shaft seal is completed.

[0032] Example 2: A novel shaft seal suitable for high-temperature and corrosive conditions This embodiment provides a novel shaft seal suitable for high-temperature and corrosive operating conditions. This condition is applied to chemical pump equipment with a working pressure of 2-5 MPa, a working temperature of 80℃~150℃, a medium containing corrosive chemical solutions, and a rotating shaft speed of 1000-3000 r / min.

[0033] 1. Component structure and material selection: The main frame 100 and the secondary frame 110 are made of 304 or 316L stainless steel and are formed into an integrated L-shaped structure by casting. The main frame 100 has an outer diameter of 100mm, an inner diameter of 80mm, and an axial length of 30mm. The secondary frame 110 is located on the upper part of the inner wall of the main frame 100, with a radial length of 12mm and an axial length of 18mm. The inner wall of the secondary frame 110 is provided with an annular positioning groove with a depth of 1.5mm.

[0034] The spacer 120 is made of polytetrafluoroethylene (PTFE) in a ring structure with an outer diameter of 98 mm, an inner diameter of 85 mm, and a thickness of 6 mm. The outer circular surface of the spacer 120 is provided with a flange with a thickness of 1.5 mm, which is installed in conjunction with the positioning groove of the sub-frame 110 with a fitting clearance of 0.03 mm. The polytetrafluoroethylene material has excellent corrosion resistance.

[0035] The first sealing lip 130 and the second sealing lip 140 are made of pure polytetrafluoroethylene (PTFE) with a Shore hardness of 58-65. Pure PTFE has excellent high temperature resistance and corrosion resistance, and can adapt to chemical solution media and high temperature conditions. The inner side of the sealing lip is bent downward with a bending angle of 25° and an arc radius of 3mm. The hollow cavity of the first sealing lip 130 has a diameter of 72mm and a length of 10mm. Three annular sealing grooves are provided on the inner side of the cavity, with a groove depth of 0.3mm and a groove width of 0.8mm, to enhance the sealing effect and lubrication performance.

[0036] The spring 150 is made of 316 stainless steel wire with a diameter of 1.5mm. It has a ring structure with an inner diameter of 75mm, an outer diameter of 78mm, 10 coils, and a spring force of 8-12N. It has good corrosion resistance and elastic stability and can work for a long time in high-temperature and corrosive environments.

[0037] The sealing gasket 160 is made of polytetrafluoroethylene (PTFE), with an outer diameter of 98 mm, an inner diameter of 87 mm, and a thickness of 1 mm. It is installed between the second sealing lip 140 and the main frame 100 by compression and fixing. The PTFE gasket has strong corrosion resistance and can effectively prevent the penetration of corrosive media.

[0038] The main frame 100 is provided with a positioning boss with a height of 3mm on the outside. The sealing groove is 4mm wide and 2.5mm deep. Fluororubber O-rings (outer diameter 100mm, wire diameter 2.5mm) are installed in the groove to ensure the sealing performance between the main frame 100 and the equipment shell and to adapt to high temperature and corrosion conditions.

[0039] 2. Assembly process: First, the sealing gasket 160 is embedded into the sealing groove of the main frame 100; then the second sealing lip 140 is installed between the spacer 120 and the sealing gasket 160; then the spacer 120 is placed on the second sealing lip 140; next, the spring 150 is installed into the hollow cavity of the first sealing lip 130; the position of the spring 150 is adjusted to be centered; then the first sealing lip 130 is installed between the sub-frame 110 and the spacer 120; so that the first sealing lip 130 and the spacer 120 on the inner wall of the sub-frame 110 are tightly fitted; finally, the inner frame 110 is embedded into the main frame 100; all components are pressed tightly together by the spinning sealing technology; the overall assembly of the shaft seal is completed.

[0040] Example 3: A novel shaft seal suitable for high-speed motors This embodiment provides a novel shaft seal suitable for high-speed motors with a speed of 3000-5000 r / min, a working pressure of 0.1-0.5 MPa, a working temperature of -30℃ to 100℃, and a medium of motor lubricating oil. It has high requirements for friction resistance and sealing performance.

[0041] 1. Component structure and material selection: The main frame 100 and the secondary frame 110 are made of 6061 aluminum alloy and are formed into an integrated L-shaped structure through extrusion molding. The aluminum alloy material is lightweight and can reduce the inertial force during high-speed rotation. The main frame 100 has an outer diameter of 60mm, an inner diameter of 45mm, and an axial length of 12mm; the secondary frame 110 has a radial length of 58mm, an axial length of 4mm, and an annular positioning groove with a depth of 0.8mm is set on the inner wall.

[0042] The partition 120 is made of 1060 aluminum plate to form a ring structure with an outer diameter of 58mm, an inner diameter of 50mm, and a thickness of 3mm. The 1060 aluminum plate has good sealing and lightweight performance. The outer circular flange of the partition 120 has a thickness of 0.8mm, and the gap between it and the positioning groove of the sub-frame 110 is 0.04mm.

[0043] The first sealing lip 130 and the second sealing lip 140 are made of modified graphite with a Shore hardness of 55-65. Modified graphite has good high and low temperature resistance and elasticity, and a low coefficient of friction, making it suitable for high-speed operation. The inner side of the sealing lip is bent downward at a bending angle of 35° and the radius of the arc at the bend is 1.5mm, reducing the frictional contact area. The hollow cavity of the first sealing lip 130 has a diameter of 40mm and a length of 7mm. An annular sealing groove is provided on the inner side of the cavity, with a groove depth of 0.2mm and a groove width of 0.6mm, to store a lubricating oil film.

[0044] The spring 150 is made of 304 stainless steel wire with a diameter of 1.0mm. It has a ring structure with an inner diameter of 43mm and an outer diameter of 45mm. It has 7 coils and a spring force of 3-5N. The spring force is moderate, which can ensure a tight seal and reduce frictional resistance.

[0045] The sealing gasket 160 is made of silicone, with an outer diameter of 52mm, an inner diameter of 45mm, and a thickness of 1.5mm. It is fixed by vulcanization bonding. The silicone gasket has good elasticity and can absorb the impact of motor vibration on the sealing structure.

[0046] The outer positioning boss of the main frame 100 has a height of 1.5mm, a sealing groove width of 2.5mm and a depth of 1.5mm, and a silicone O-ring (outer diameter 60mm, wire diameter 1.5mm) is installed in the groove.

[0047] 2. Assembly process: First, the sealing gasket 160 is embedded into the sealing groove of the main frame 100; then the second sealing lip 140 is installed between the spacer 120 and the sealing gasket 160; then the spacer 120 is placed on the second sealing lip 140; next, the spring 150 is installed into the hollow cavity of the first sealing lip 130; the position of the spring 150 is adjusted to be centered; then the first sealing lip 130 is installed between the sub-frame 110 and the spacer 120; so that the first sealing lip 130 and the spacer 120 on the inner wall of the sub-frame 110 are tightly fitted; finally, the inner frame 110 is embedded into the main frame 100; all components are pressed tightly together by the spinning sealing technology; the overall assembly of the shaft seal is completed.

[0048] Working principle: During assembly, the novel shaft seal is first installed by inserting the spring 150 into the hollow cavity of the first sealing lip 130 and fixing its position with a retaining ring. Then, the first sealing lip 130 is installed between the sub-frame 110 and the spacer 120, ensuring that the outer side of the first sealing lip 130 is tightly fitted against the inner wall of the sub-frame 110 and the bottom of the spacer 120. Next, the second sealing lip 140 is installed between the top of the spacer 120 and the main frame 100. Then, the sealing gasket 160 is embedded in the gap between the second sealing lip 140 and the main frame 100 and fixed by vulcanization bonding or compression. Finally, the assembled shaft seal is installed into the mounting hole of the equipment housing, achieving precise positioning through the positioning boss of the main frame 100. The main frame 100 and the housing are sealed by an O-ring. Under the preload of the spring 150, the inner sides of the first sealing lip 130 and the second sealing lip 140 of the shaft seal are tightly fitted against the rotating shaft surface, forming a double sealing surface.

[0049] During equipment operation, the rotating shaft drives the sealing lip to perform slight frictional movement synchronously. Under the preload of the spring 150, the first sealing lip 130 always adheres to the shaft surface, preventing most of the medium from leaking outward and forming the first sealing barrier. A small amount of medium that may have penetrated through the first sealing lip 130 will be blocked by the spacer 120 in the buffer cavity between the two sealing lips, preventing further leakage outward. At the same time, the second sealing lip 140 and the sealing gasket 160 form the second sealing barrier, completely blocking the medium leakage path and achieving double sealing protection.

[0050] When the sealing lip experiences slight wear due to prolonged operation, the elastic compensation capability of the spring 150 pushes the sealing lip towards the shaft surface to compensate for the wear, ensuring that the sealing lip always remains in contact with the shaft surface and maintaining sealing performance. The arc-shaped bending structure of the sealing lip can adapt to slight eccentricity and vibration of the shaft, reducing frictional resistance and wear, while also reducing the generation of frictional heat. The integrated skeleton structure ensures overall rigidity and stability, preventing skeleton deformation or loosening of sealing components due to vibration or load. The sealing gasket 160 effectively seals the gap between the second sealing lip 140 and the main skeleton 100, eliminating potential leakage channels.

[0051] Furthermore, the annular sealing groove inside the first sealing lip 130 can store a small amount of lubricating medium, forming a lubricating oil film. This not only reduces friction and wear between the sealing lip and the shaft, extending the service life of the sealing lip, but also further enhances the sealing effect and prevents medium leakage. The O-ring auxiliary seal between the main frame 100 and the housing prevents medium leakage from the mating surface between the shaft seal and the housing, ensuring the reliability of the overall sealing performance of the shaft seal.

[0052] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A novel shaft seal, characterized in that: Including the main frame (100); A secondary frame (110) is provided on the inner wall of the main frame (100). A partition (120) is installed on the secondary frame (110). A first sealing lip (130) is installed between the secondary frame (110) and the partition (120). A spring (150) is installed in the inner cavity of the first sealing lip (130). A second sealing lip (140) is installed between the partition (120) and the main frame (100). A sealing gasket (160) is installed between the second sealing lip (140) and the main frame (100).

2. The novel shaft seal according to claim 1, characterized in that: The main frame (100) and the secondary frame (110) have L-shaped cross-sections, and the secondary frame (110) and the main frame (100) are an integral structure.

3. The novel shaft seal according to claim 1, characterized in that: The partition (120) has an annular structure, with the first sealing lip (130) and the second sealing lip (140) located at the bottom and top of the partition (120), respectively.

4. A novel shaft seal according to claim 1, characterized in that: The first sealing lip (130) has a hollow cavity in the middle, and the spring (150) is located in the hollow cavity.

5. A novel shaft seal according to claim 1, characterized in that: The sealing gasket (160) has an annular structure and is fixedly connected to the second sealing lip (140) and the main frame (100).

6. A novel shaft seal according to claim 1, characterized in that: The inner sides of the first sealing lip (130) and the second sealing lip (140) are bent downwards, and the bend is arc-shaped.

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