Skeleton oil seal with dual mode compensation system
By using a skeleton oil seal with a dual-mode compensation system, combined with ordinary metal springs and SMA shape memory alloy springs, the problem of radial force reduction in skeleton oil seals at high temperatures is solved, achieving effective sealing and optimized thermal management under extreme temperatures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- XINGHUA DAIYAO YONGSHENG RUBBER PROD FACTORY
- Filing Date
- 2025-08-12
- Publication Date
- 2026-06-23
AI Technical Summary
When the rubber of the skeleton oil seal softens under extreme high temperatures, the radial force decreases, which ordinary self-tightening springs cannot effectively compensate for, thus affecting the sealing performance.
The system employs a dual-mode compensation system, using a combination of ordinary metal springs and SMA shape memory alloy springs. The ordinary springs provide the main radial force at low temperatures, while the SMA springs compensate for the radial force through phase change expansion at high temperatures. Combined with a wave-shaped sealing lip structure, the system enhances the convection and heat dissipation of the lubricating oil film.
It maintains good sealing performance in both high and low temperature environments, extends service life and optimizes thermal management, and solves the problems of rubber softening and the impact on the performance of self-tightening springs.
Smart Images
Figure CN224397128U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to skeleton oil seals, and more particularly to a skeleton oil seal with a dual-mode compensation system. Background Technology
[0002] In mechanical equipment, oil seals are typically used to isolate lubricated components from the external environment, preventing lubricant leakage. Skeleton oil seals, on the other hand, consist of a skeleton made by adding metal or other materials to the sealing rubber component, reinforcing and supporting the oil seal to maintain its shape and tension. However, with industrial development, there is a need for equipment operating in extreme environments. The performance of ordinary skeleton oil seals is significantly affected by temperature. At excessively low temperatures, the rubber material hardens, leading to increased wear; at excessively high temperatures, the rubber material softens, resulting in a loss of resilience. Both high and low temperatures affect sealing performance. When the rubber's performance is affected, the self-tightening spring inside the sealing lip needs to function to tighten the sealing lip and maintain the oil seal's sealing performance. However, with industrial development, the operating temperature limits of equipment are being broken. Extreme high temperatures also affect the performance of the self-tightening spring. Furthermore, the radial force decreases after the rubber softens, thus the sealing performance of the skeleton oil seal is still significantly affected. Summary of the Invention
[0003] This invention addresses the problem that the radial force of a skeleton oil seal decreases due to rubber softening at extreme high temperatures, and that ordinary self-tightening springs cannot compensate for the high temperature effect. Therefore, it proposes a skeleton oil seal with a dual-mode compensation system.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] A skeleton oil seal with a dual-mode compensation system includes a metal skeleton, a rubber layer, a first self-tightening spring, and a second self-tightening spring. The rubber layer wraps around the metal skeleton. A dustproof lip and a sealing lip are provided on one side of the rubber layer located on the inner periphery of the skeleton oil seal. The dustproof lip is located on the side away from the lubricating oil after the skeleton oil seal is installed. The sealing lip is located on the side of the skeleton oil seal facing the inner periphery, with a first sealing lip and a second sealing lip. A wavy structure exists between the first and second sealing lips. A circumferential groove is provided on the side of the sealing lip facing the outer periphery of the skeleton oil seal. Both the first and second self-tightening springs are installed within the circumferential groove. The first self-tightening spring is a common metal spring, and the second self-tightening spring is an SMA shape memory alloy spring. The diameter of the second self-tightening spring is smaller than the diameter of the first self-tightening spring, and the second self-tightening spring is nested inside the first self-tightening spring.
[0006] Preferably, the first sealing lip is located between the second sealing lip and the dustproof lip, and the axial thickness of the first sealing lip is greater than the axial thickness of the second sealing lip.
[0007] Preferably, a recessed structure is formed between the first sealing lip and the second sealing lip, and the included angle A between the first sealing lip and the second sealing lip is 60°-120°.
[0008] Preferably, the surfaces of the first sealing lip and the second sealing lip are coated with a PTFE and molybdenum disulfide coating.
[0009] Preferably, the first self-tightening spring is made of SWP high-carbon steel wire.
[0010] Preferably, the second self-tightening spring is made of NiTiNb alloy.
[0011] Preferably, when the operating temperature of the skeleton oil seal is below 150°C, the first self-tightening spring provides at least 80% of the radial force; when the operating temperature of the skeleton oil seal is above 150°C, the second self-tightening spring provides at least 90% of the radial force.
[0012] Preferably, when the working temperature of the skeleton oil seal is higher than 150°C, the phase change expansion of the second self-tightening spring increases the radial compensation force to 120%.
[0013] Compared with existing technologies, the beneficial effects of this invention are as follows: Two self-tightening springs are incorporated, with the SMA shape memory alloy spring nested inside a regular stainless steel spring, forming a dual-mode compensation system. At low temperatures, the regular spring provides most of the radial force, preventing overpressure wear caused by SMA low-temperature embrittlement. At high temperatures, the SMA shape memory alloy spring provides most of the radial force, and the SMA undergoes phase transformation and expansion, increasing the compensation force to 120%, thus solving the problem of rubber softening at high temperatures. Furthermore, the sealing lips are designed as two wavy shapes at their contact with the sealing surface, generating micro-vortices during shaft rotation, which enhances the convection and heat dissipation of the lubricating oil film. Attached Figure Description
[0014] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0015] Figure 1 This is a schematic diagram of the axial cross-sectional structure of a skeleton oil seal with a dual-mode compensation system;
[0016] Figure 2This is an enlarged schematic diagram of the axial cross-sectional structure of a skeleton oil seal with a dual-mode compensation system.
[0017] The components include a metal skeleton 1, a rubber layer 2, a first self-tightening spring 3, a second self-tightening spring 4, a dustproof lip 21, a sealing lip 22, a first sealing lip 221, and a second sealing lip 222. Detailed Implementation
[0018] To provide a better understanding of the purpose, structure, features, and functions of this utility model, detailed descriptions are provided below with reference to specific embodiments.
[0019] In the description of this utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0020] Please refer to the reference. Figure 1 and Figure 2 A skeleton oil seal with a dual-mode compensation system includes a metal skeleton 1, a rubber layer 2, a first self-tightening spring 3, and a second self-tightening spring 4. The rubber layer 2 is wrapped around the metal skeleton 1. A dustproof lip 21 and a sealing lip 22 are provided on the side of the rubber layer 2 located on the inner periphery of the skeleton oil seal. The dustproof lip 21 is located on the side away from the lubricating oil after the skeleton oil seal is installed, and the sealing lip 22 is located on the side of the skeleton oil seal close to the lubricating oil after the skeleton oil seal is installed. A first sealing lip 221 and a second sealing lip 222 are provided on the side of the sealing lip 22 facing the inner periphery of the skeleton oil seal. The first sealing lip 221 and the second sealing lip 222 have a wavy structure. A circumferential groove is provided on the side of the sealing lip 22 facing the outer periphery of the skeleton oil seal. The first self-tightening spring 3 and the second self-tightening spring 4 are both installed in the circumferential groove. The first self-tightening spring 3 is a common metal spring, and the second self-tightening spring 4 is an SMA shape memory alloy spring. The diameter of the second self-tightening spring 4 is smaller than the diameter of the first self-tightening spring 3, and the second self-tightening spring 4 is nested inside the first self-tightening spring 3.
[0021] This utility model discloses a skeleton oil seal with a dual-mode compensation system. Specifically, the dual-mode compensation system consists of two springs: a first self-tightening spring 3 (a common metal spring) and a second self-tightening spring 4 (an SMA shape memory alloy spring). These two springs differ in size and material; the common metal spring is larger and plays a primary self-tightening sealing role in normal or low-temperature environments. Especially in low-temperature environments, the common metal spring is mainly responsible for preventing overpressure wear caused by low-temperature embrittlement of the SMA. In high-temperature environments, the SMA shape memory alloy spring is mainly responsible for operation. The SMA undergoes phase change expansion, increasing the compensation force to 120%, effectively solving the problem of rubber softening at high temperatures. The two self-tightening springs cooperate and complement each other in both high and low-temperature environments, achieving a good dual-mode compensation effect.
[0022] In some embodiments, when the operating temperature of the skeleton oil seal is below 150°C, the first self-tightening spring 3 provides at least 80% radial force; when the operating temperature of the skeleton oil seal is above 150°C, the second self-tightening spring 4 provides at least 90% radial force.
[0023] In some embodiments, when the working temperature of the skeleton oil seal is higher than 150°C, the phase change expansion of the second self-tightening spring 4 increases the radial compensation force to 120%, and the phase change contraction of the SMA memory alloy at high temperature provides a larger radial force to offset the reduction in radial force caused by the softening of the rubber layer 2, ensuring that the radial force of the skeleton oil seal is similar to that at room temperature.
[0024] In some embodiments, the first self-tightening spring 3 is made of SWP high-carbon steel wire, which has strong anti-creep properties and can perform better in normal temperature and low temperature environments.
[0025] In some implementations, the second self-tightening spring 4 is made of NiTiNb alloy with a phase transformation temperature of 120°C. Under high-temperature conditions, the phase transformation expands, which can greatly improve its compensation capacity.
[0026] This utility model discloses a skeleton oil seal with a dual-mode compensation system. Its sealing lips 22 are configured as two, forming a wavy or multi-segmented curved surface at their contact with the sealing surface. During shaft rotation, micro-vortices are generated, enhancing the convective heat dissipation of the lubricating oil film. This reduces wear on the rubber layer 2 caused by rotational friction, extends the service life of the skeleton oil seal, and the improved thermal management is beneficial for its operation in high-temperature environments. Depending on the actual size and application of the skeleton oil seal, more than two seals can also be designed.
[0027] In some embodiments, the first sealing lip 221 is located between the second sealing lip 222 and the dustproof lip 21. The axial thickness of the first sealing lip 221 is greater than that of the second sealing lip 222. The first sealing lip 221 has the largest contact area with the sealing surface and plays the main sealing role. The second sealing lip 222 can block iron filings or oil stains from the wear of internal parts of the equipment from the skeleton oil seal. On the other hand, it can form a wave-shaped structure with the first sealing lip 221, generating micro-vortices when the shaft rotates, which can enhance the convection heat dissipation of the lubricating oil film and optimize the thermal management of the skeleton oil seal.
[0028] In some embodiments, a recessed structure is formed between the first sealing lip 221 and the second sealing lip 222, and the included angle A between the first sealing lip 221 and the second sealing lip 222 is 60°-120°.
[0029] In some embodiments, the surfaces of the first sealing lip 221 and the second sealing lip 222 are coated with PTFE and molybdenum disulfide coatings, which effectively reduces the coefficient of friction and alleviates the wear of the skeleton oil seal.
[0030] This utility model has been described by the above-described embodiments; however, these embodiments are merely examples for implementing this utility model. It must be noted that the disclosed embodiments do not limit the scope of this utility model. Conversely, any modifications and refinements made without departing from the spirit and scope of this utility model are within the scope of patent protection of this utility model.
Claims
1. A skeleton oil seal with a dual-mode compensation system, characterized in that: The device includes a metal skeleton, a rubber layer, a first self-tightening spring, and a second self-tightening spring. The rubber layer wraps around the metal skeleton. A dustproof lip and a sealing lip are provided on one side of the rubber layer located on the inner periphery of the skeleton oil seal. The dustproof lip is positioned on the side away from the lubricating oil after the skeleton oil seal is installed. The sealing lip is positioned on the side of the skeleton oil seal closest to the lubricating oil after installation. A first sealing lip and a second sealing lip are provided on the side of the sealing lip facing the inner periphery of the skeleton oil seal. A wavy structure exists between the first and second sealing lips. A circumferential groove is provided on the side of the sealing lip facing the outer periphery of the skeleton oil seal. Both the first and second self-tightening springs are installed within the circumferential groove. The first self-tightening spring is a common metal spring, and the second self-tightening spring is an SMA shape memory alloy spring. The diameter of the second self-tightening spring is smaller than the diameter of the first self-tightening spring, and the second self-tightening spring is nested inside the first self-tightening spring.
2. The skeleton oil seal with a dual-mode compensation system as described in claim 1, characterized in that: The first sealing lip is located between the second sealing lip and the dustproof lip, and the axial thickness of the first sealing lip is greater than the axial thickness of the second sealing lip.
3. The skeleton oil seal with a dual-mode compensation system as described in claim 1, characterized in that: A recessed structure is formed between the first sealing lip and the second sealing lip, and the included angle A between the first sealing lip and the second sealing lip is 60°-120°.
4. The skeleton oil seal with a dual-mode compensation system as described in claim 1, characterized in that: The surfaces of the first sealing lip and the second sealing lip are coated with PTFE and molybdenum disulfide.
5. The skeleton oil seal with a dual-mode compensation system as described in claim 1, characterized in that: The first self-tightening spring is made of SWP high carbon steel wire.
6. The skeleton oil seal with a dual-mode compensation system as described in claim 1, characterized in that: The second self-tightening spring is made of NiTiNb alloy.
7. The skeleton oil seal with a dual-mode compensation system as described in claim 1, characterized in that: When the operating temperature of the skeleton oil seal is below 30°C, the first self-tightening spring provides at least 80% of the radial force; when the operating temperature of the skeleton oil seal is above 150°C, the second self-tightening spring provides at least 90% of the radial force.
8. The skeleton oil seal with a dual-mode compensation system as described in claim 7, characterized in that: When the working temperature of the skeleton oil seal is higher than 150°C, the second self-tightening spring undergoes phase change expansion, and the radial compensation force increases to 120%.