A sealing structure of a hub bearing

Abstract

This utility model discloses a sealing structure for a wheel hub bearing, relating to the field of rolling bearing technology. It includes a wheel hub bearing, comprising an inner ring and an outer ring. A first metal skeleton is fitted onto the inner ring near the outer ring, and a second metal skeleton is fitted onto the outer ring near the inner ring. A rubber ring body is fitted onto the side of the first and second metal skeletons close to each other. A rubber clamp is fitted onto the outer ring near the top of the second metal skeleton. The rubber ring body and the rubber clamp are used to reduce friction and prevent grease leakage. This utility model combines nitrile rubber with a double-contact lip and a radial labyrinth structure through an outer rubber lip, a middle rubber lip, and an inner rubber lip, reducing friction while ensuring sealing reliability through material properties.

Description

Technical Field

[0001] This utility model relates to the field of rolling bearing technology, and in particular to a sealing structure for a wheel hub bearing. Background Technology

[0002] In the automotive industry, wheel bearing units, as key components, bear the load and ensure precise transmission; their performance directly affects the energy efficiency and operational stability of vehicles. With the advancement of the "carbon peak and carbon neutrality" goals, reducing the frictional power consumption of automotive components to improve energy efficiency has become an important research direction.

[0003] In current wheel hub bearing applications, fluororubber materials and three-contact lip seals are commonly used. While this structure offers stable sealing performance, it generates significant frictional torque, impacting the bearing's frictional power consumption. Increased frictional torque directly leads to higher bearing frictional power consumption; this energy loss not only reduces the efficiency of the automotive transmission system but also increases fuel consumption. While fluororubber seals possess excellent chemical corrosion resistance and aging resistance, their high frictional torque can potentially disrupt the lubrication state inside the bearing.

[0004] To address the issue of high frictional torque impacting bearing frictional power consumption, the traditional three-contact lip seal structure was improved by reducing one contact lip, combining a double-contact lip with a radial labyrinth structure. A tortuous small gap is formed between the stationary seal and the inner ring, creating a radial labyrinth seal. This structure utilizes the labyrinth gap to create a flow channel with extremely high flow resistance, preventing grease leakage and the entry of external contaminants, while simultaneously reducing frictional losses in contact seals. The reduction in frictional torque directly decreases bearing frictional power consumption, improving the energy utilization efficiency of the transmission system. Furthermore, the labyrinth structure effectively blocks solid particles such as dust and moisture, reducing wear on the contact lips caused by impurities and extending the seal's lifespan.

[0005] However, in the current use of sealing rings, there is still a problem of rapid aging of fluororubber sealing rings. After aging, the elasticity, resilience, and sealing performance of fluororubber sealing rings will significantly decrease, leading to grease leakage or the intrusion of external contaminants into the bearing. Moreover, seal failure will lead to poor bearing lubrication, accelerated wear and heat generation, and in turn, cause bearing burns, cracks, and other failures. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a sealing structure for wheel hub bearings, which solves the problem of high frictional torque affecting bearing frictional power consumption.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A sealing structure for a wheel hub bearing includes a wheel hub bearing, an inner bearing ring, and an outer bearing ring. A first metal skeleton is fitted onto the inner bearing ring near the outer bearing ring, and a second metal skeleton is fitted onto the outer bearing ring near the inner bearing ring. A rubber ring body is fitted onto the side of the first and second metal skeletons close to each other. A rubber clamp is fitted onto the outer bearing ring near the top of the second metal skeleton. The rubber ring body and the rubber clamp are used to reduce friction and prevent grease leakage. The sealing performance far exceeds that of traditional single-lip or double-lip seals, significantly extending the service life of the grease and reducing bearing dry friction, burning, and other failures caused by grease leakage.

[0009] As a further improvement of this utility model, the rubber ring body also includes a rubber outer lip, a rubber middle lip, and a rubber inner lip. The rubber outer lip is fitted to the side of the rubber clamp near the second metal frame, the rubber middle lip is located in the middle of the second metal frame, and the rubber inner lip is fitted to the side of the second metal frame away from the inner ring of the bearing. Through the rubber outer lip, rubber middle lip, and rubber inner lip, the overall rubber ring body is designed with a radial labyrinth formed by zigzag gaps.

[0010] As a further improvement of this utility model, the rubber ring body and the rubber clamp are made of nitrile rubber, and the temperature resistance range of the nitrile rubber is -40~+120℃. This prevents grease leakage due to seal failure.

[0011] As a further improvement of this invention, the sealing surfaces of the rubber ring body are designed with a tortuous gap to form a radial labyrinth. This radial labyrinth improves sealing performance while reducing frictional torque. The radial labyrinth forces grease or contaminants to leak or infiltrate through a series of narrow bends, thereby further enhancing the sealing effect.

[0012] As a further improvement of this utility model, the lip inclination angle of the rubber intermediate lip is set between 60° and 70°, the lip thickness of the rubber intermediate lip is set between 0.5° and 0.7mm, the lip length of the rubber intermediate lip is set between 3.6° and 4.0mm, and the interference fit of the rubber intermediate lip is set between 0.30° and 0.40mm. The 60° to 70° inclination angle allows the contact surface between the sealing lip and the inner / outer ring of the bearing to be wedge-shaped, generating uniform radial contact pressure under the action of the interference fit.

[0013] As a further improvement of this utility model, the tortuous gap is used to form a flow channel with extremely high flow resistance.

[0014] Compared with the prior art, the advantages of this utility model are as follows:

[0015] 1. By combining nitrile rubber with a double-contact lip and a radial labyrinth structure through an outer rubber lip, a middle rubber lip, and an inner rubber lip, friction is reduced while ensuring reliable sealing through material properties. The tortuous, narrow-gap design forces grease to traverse a series of narrow bends before leakage. Each time the fluid passes through a bend, the inertial impact on the wall causes energy dissipation and a sharp drop in flow velocity. Simultaneously, some fluid is trapped, forming an "oil seal," significantly increasing leakage resistance. The double-contact lip design ensures contact sealing through elastic deformation of the lip even under static or low-speed conditions, forming the first line of defense. The labyrinth structure acts as the second line of defense; even if the contact lips develop tiny gaps due to wear, the labyrinth can still prevent leakage through physical barrier.

[0016] 2. The rubber intermediate lip, with a lip thickness of 0.5~0.7mm, a lip length of 3.6~4.0mm, and an interference fit of 0.30~0.40mm, ensures that the sealing lip has sufficient rigidity to resist the impact of high-pressure grease while also possessing sufficient elasticity to accommodate minor deformations during bearing operation. The lip length of 3.6~4.0mm creates a longer sealing path, requiring grease to pass through a longer, more tortuous channel to leak, significantly increasing fluid resistance. The 60~70° tilt angle allows the sealing lip to wedge against the inner / outer ring of the bearing, preventing grease leakage and avoiding lip wear or tear caused by excessive local pressure. The synergistic design of the tilt angle, lip thickness, lip length, and interference fit ensures that the seal maintains a low leakage rate under both static and dynamic conditions. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0018] Figure 2 This utility model Figure 1 A magnified three-dimensional structural diagram at point A in the middle.

[0019] In the diagram: 101, bearing inner ring; 102, bearing outer ring; 103, metal skeleton one; 104, metal skeleton two; 201, rubber ring body; 202, rubber clamp; 203, rubber outer lip; 204, rubber middle lip; 205, rubber inner lip. Detailed Implementation

[0020] To make the above-mentioned objectives, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0021] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0022] See attached document Figure 1 -Appendix Figure 2 A sealing structure for a wheel hub bearing includes an inner bearing ring 101, an outer bearing ring 102, a first metal skeleton 103, a second metal skeleton 104, a rubber ring body 201, a rubber clamp 202, a rubber outer lip 203, a rubber middle lip 204, and a rubber inner lip 205.

[0023] This utility model includes a hub bearing, which further includes an inner bearing ring 101 and an outer bearing ring 102. A metal skeleton 103 is fitted onto the side of the inner bearing ring 101 near the outer bearing ring 102, and a metal skeleton 204 is fitted onto the side of the outer bearing ring 102 near the inner bearing ring 101. A rubber ring body 201 is fitted onto the side of the metal skeletons 103 and 204 close to each other. A rubber clamp 202 is fitted onto the top of the metal skeleton 204 on the side of the outer bearing ring 102 near the metal skeleton 204. The rubber ring body 201 and the rubber clamp 202 are used to reduce friction and prevent grease leakage. The rubber ring body 201 serves as the main sealing layer, closely adhering to the metal skeletons 103 and 204, forming the first line of defense to prevent grease from leaking from the inside of the bearing. The rubber clamp 202 serves as an auxiliary seal or labyrinth structure, creating a tortuous flow channel at the top of the outer ring 102 of the bearing to increase the resistance of the grease leakage path while preventing external contaminants from entering.

[0024] Its sealing performance far exceeds that of traditional single-lip or double-lip seals, significantly extending the service life of grease and reducing bearing dry friction, burning and other failures caused by grease leakage.

[0025] The rubber ring body 201 and rubber clamp 202 are made of nitrile rubber, which has a temperature resistance range of -40 to +120℃. The sealing surfaces of the rubber ring body 201 are designed with a tortuous gap to form a radial labyrinth. The radial labyrinth is used to improve sealing performance and reduce frictional torque, while the tortuous gap is used to form a flow channel with extremely high flow resistance. The traditional three-contact lip seal structure is improved by reducing one contact lip and combining a double-contact lip with a radial labyrinth structure. Specifically, a radial labyrinth seal is formed by creating a tortuous small gap between the stationary seal and the bearing outer ring 102. This structure utilizes the labyrinth gap to form a flow channel with extremely high flow resistance, preventing grease leakage and the entry of external contaminants, while reducing frictional losses of the contact seal. By designing a tortuous small gap between the stationary seal and the bearing outer ring 102, grease must pass through a series of narrow bends to leak.

[0026] The rubber ring body 201 also includes a rubber outer lip 203, a rubber intermediate lip 204, and a rubber inner lip 205. The rubber outer lip 203 is fitted onto the side of the rubber clamp 202 closest to the metal skeleton 104. The rubber intermediate lip 204 is located in the middle of the metal skeleton 104. The rubber inner lip 205 is fitted onto the side of the metal skeleton 104 furthest from the bearing inner ring 101. The lip inclination angle of the rubber intermediate lip 204 is set between 60° and 70°. This inclination angle allows the sealing lip to be wedge-shaped against the contact surface of the bearing inner ring 101 or bearing outer ring 102, generating uniform radial contact pressure under the interference fit. This design prevents grease leakage and avoids lip wear or tear caused by excessive local pressure. The thickness of the rubber intermediate lip 204 is set between 0.5 and 0.7 mm. This thickness ensures sufficient rigidity to resist the impact of high-pressure grease while providing enough elasticity to accommodate minor deformations during bearing operation, preventing buckling due to excessive thinness or increased frictional torque due to excessive thickness. The lip length of the rubber intermediate lip 204 is set between 3.6 and 4.0 mm. This length creates a longer sealing path, requiring grease to pass through a longer, more tortuous channel to leak, significantly increasing fluid resistance. Furthermore, the longer lip traps more contaminants, preventing them from entering the bearing. The interference fit of the rubber intermediate lip 204 is set between 0.30 and 0.40 mm. This interference fit ensures sufficient initial contact pressure between the sealing lip and the bearing surface after installation, forming an effective seal. The coordinated design of tilt angle, lip thickness, lip length and interference fit enables the seal to maintain a low leakage rate under both static and dynamic conditions.

[0027] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A sealing structure for a hub bearing, comprising a hub bearing, characterized in that, The hub bearing also includes an inner bearing ring (101) and an outer bearing ring (102). A metal skeleton one (103) is attached to the side of the inner bearing ring (101) near the outer bearing ring (102). A metal skeleton two (104) is attached to the side of the outer bearing ring (102) near the inner bearing ring (101). A rubber ring body (201) is attached to the side of the metal skeleton one (103) and the metal skeleton two (104) close to each other. A rubber clamp (202) is attached to the top of the metal skeleton two (104) on the side of the outer bearing ring (102) near the metal skeleton two (104). The rubber ring body (201) and the rubber clamp (202) are used to reduce friction and prevent grease leakage.

2. The sealing structure of a wheel hub bearing according to claim 1, characterized in that, The rubber ring body (201) also includes a rubber outer lip (203), a rubber middle lip (204) and a rubber inner lip (205). The rubber outer lip (203) is attached to the side of the rubber clamp (202) close to the metal frame two (104). The rubber middle lip (204) is located in the middle of the metal frame two (104). The rubber inner lip (205) is attached to the side of the metal frame two (104) away from the bearing inner ring (101).

3. The sealing structure of a wheel hub bearing according to claim 1, characterized in that, The rubber ring body (201) and the rubber clamp (202) are made of nitrile rubber, and the temperature resistance range of the nitrile rubber is -40~+120℃.

4. The sealing structure of a wheel hub bearing according to claim 1, characterized in that, The sealing surfaces of the rubber ring body (201) are designed with a tortuous gap to form a radial labyrinth, which is used to improve sealing performance and reduce friction torque.

5. The sealing structure of a wheel hub bearing according to claim 2, characterized in that, The lip tilt angle of the rubber intermediate lip (204) is set between 60 and 70°, the lip thickness of the rubber intermediate lip (204) is set between 0.5 and 0.7 mm, the lip length of the rubber intermediate lip (204) is set between 3.6 and 4.0 mm, and the interference of the rubber intermediate lip (204) is set between 0.30 and 0.40 mm.

6. The sealing structure of a wheel hub bearing according to claim 4, characterized in that, The tortuous gaps are used to form flow channels with extremely high flow resistance.

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