Seal assembly and bearing device

Abstract

The invention relates to a sealing assembly for forming a dynamic seal between a first component and a second component, the sealing assembly comprising a first sealing body for fastening to the first component and a second sealing body for fastening to the second component, the first sealing body having a first receiving portion, the second sealing body having a second receiving portion, and the second sealing body having a second receiving portion. The first sealing body is provided with a first containing part, the second sealing body is provided with a second containing part, the first containing part and the second containing part jointly form an annular containing cavity in a non-contact mode, and the annular containing cavity is used for being filled with magnetic fluid. The first sealing body or the second sealing body is provided with a magnetic piece used for keeping the magnetic fluid in the annular containing cavity through magnetic force, so that the first sealing body and the second sealing body form non-contact dynamic sealing, and a contact lip between the first sealing body and the second sealing body is replaced.

Description

Technical Field

[0001] This invention relates to sealing technology, specifically a dynamic sealing technology, and more particularly to a sealing assembly for wheel hub bearings. Bearings in wheel hub drive systems typically use a seal assembly structure consisting of a skeleton, rubber, and a sealing lip, installed between the inner and outer rings of the bearing. This sealing assembly is used to seal grease inside the bearing and retain contaminants and mud on the outside. Background Technology

[0002] This traditional sealing assembly is used to prevent contamination and murky water from entering the bearing. To achieve good sealing performance, a larger sealing lip is required to make sealing contact with the contact surface, or even more sealing lips are needed to prevent external contamination from entering. Therefore, this traditional sealing assembly has a very large sealing friction torque, which wastes a lot of energy and makes the sealing lip prone to wear.

[0003] To address this issue, existing technologies have employed methods such as using magnetic assemblies to attract magnetic fluid and replace contact lips for dynamic sealing, as disclosed in CN 104632899 A. A ring magnet is placed between the inner and outer rings of the bearing to hold the magnetic fluid and seal multiple rolling elements. However, this approach still has many drawbacks. For example, the magnetic assembly structure is complex, occupies a large space, and is too costly; the magnetic fluid comes into direct contact with internal grease and the external environment, leading to easy contamination of the internal grease and easy diffusion of the magnetic fluid into the external environment. Furthermore, the magnetic fluid is often diluted by contaminants, losing its sealing function. Summary of the Invention

[0004] The purpose of this invention is to provide an improved sealing assembly that avoids the friction problems associated with contact seals, while ensuring that the magnetic fluid in the sealing assembly does not easily diffuse, thus providing a reliable seal in complex working environments.

[0005] To achieve the above objectives, the present invention provides an improved sealing assembly installed between a first component and a second component, capable of dynamic sealing as the two components rotate relative to each other. The sealing assembly includes a first sealing body fixed to the first component and a second sealing body fixed to the second component. The first sealing body has a first receiving portion, and the second sealing body has a second receiving portion. The first and second receiving portions together form an annular receiving cavity in a non-contact manner. The annular receiving cavity is filled with a magnetic fluid. Either the first or second sealing body has a magnetic element for retaining the magnetic fluid within the annular receiving cavity by magnetic force, thereby forming a non-contact dynamic seal between the first and second sealing bodies. Therefore, no contact sealing lip is required between the first and second sealing bodies. This non-contact sealing design effectively solves the friction and wear problems caused by contact lips in the prior art, significantly reducing frictional torque and extending the service life of the sealing assembly. Furthermore, the annular receiving cavity formed by the first and second receiving portions can retain the magnetic fluid inside the sealing assembly, making the application of the magnetic fluid more reliable and effectively preventing external contaminants from entering the bearing assembly while avoiding the diffusion of the magnetic fluid into the external environment.

[0006] In a preferred embodiment of the invention, the axial cross-section of the second receiving portion of the second sealing body is open-bottomed, and the first receiving portion of the first sealing body extends into the second receiving portion. The bottle cavity of the second receiving portion forms an annular receiving cavity for accommodating magnetic fluid. The first receiving portion extends into this bottle cavity, thereby utilizing the magnetic fluid to form a dynamic seal between the first and second receiving portions. This design further reduces the diffusion of magnetic fluid, especially during long-term operation. Even if a small amount of grease is lost, the grease at the bottom of the bottle-shaped cavity can be replenished to the bottleneck portion, thus ensuring the long-term sealing performance of the bearing assembly. More preferably, the magnetic component is fixed outside the annular receiving cavity. The external magnetic component design helps to avoid the magnetic component being directly affected by the high temperature or grease inside the annular receiving cavity, thereby improving the service life and adsorption stability of the magnetic component. By fixing the magnetic component outside the annular receiving cavity, the size and shape of the magnetic component can be adjusted more flexibly to enhance the adsorption force on the magnetic fluid, thereby improving the sealing effect. More preferably, the sealing assembly has a magnetic encoder, and the aforementioned magnetic component is a component implementation of the magnetic encoder, particularly a component implementation near the second receiving portion of the sealing assembly. This design not only simplifies the structure of the bearing assembly but also eliminates the need for a separate magnetic component, reducing the number of components and cost. It utilizes the magnetic components of a magnetic encoder to maintain the hold of the magnetic fluid. This integrated design effectively reduces material and installation costs while ensuring the stability and effectiveness of the magnetic fluid within the annular cavity. Furthermore, it is also possible that the first and second receiving sections are constructed of rubber material, thereby preventing the magnetic components from adversely affecting the shape of the first and second receiving sections, allowing the annular cavity to hold the magnetic fluid more stably.

[0007] In another preferred embodiment of the invention, the second receiving portion of the second sealing body has an L-shaped structure, and the first receiving portion of the first sealing body has two sealing lips extending toward both ends of the second receiving portion, forming an annular receiving cavity with the L-shape. Magnetic fluid is filled within this annular receiving cavity and held in place by a magnetic component, forming a stable, contactless dynamic seal. More preferably, the magnetic component is fixed to or implemented by the second receiving portion. By directly fixing the magnetic component within the annular receiving cavity or implementing it by the second receiving portion, the flow direction of the magnetic fluid can be better controlled, ensuring that the magnetic fluid is always maintained in the optimal sealing position. This design effectively utilizes the support provided by the L-shaped structure, enhances the adsorption force of the magnetic component, and ensures that the magnetic fluid within the annular receiving cavity does not undergo unnecessary displacement or leakage under high-speed rotation conditions. Even more preferably, the radial dimension of the magnetic component or the second receiving portion gradually increases along the axial direction. If the magnetic component is a separate part, a ramp structure can be formed from the magnetic component; if the magnetic component is implemented by the second receiving portion, a ramp structure can be directly formed from the second receiving portion; of course, such a ramp structure can also be formed by the combination of the magnetic component and the shape of the second receiving portion, and the invention does not impose strict limitations on this. This sloping structure enhances the flow management of the magnetic fluid. During operation, the magnetic fluid is affected by centrifugal force and flows upward along the sloping structure to seal, ensuring that the grease can still effectively replenish and maintain the stability of the annular cavity under different operating conditions, thus extending the service life of the grease.

[0008] In another preferred embodiment of the invention, the magnetic fluid used is a grease containing magnetic particles. This grease not only has excellent fluidity but also adheres firmly to the annular cavity under the action of magnetic components, effectively preventing the entry of external contaminants. Even if the grease flows into the bearing assembly, it will not affect the lubrication performance of the bearing assembly. The magnetic particles, such as iron powder particles, are inexpensive and maintain good performance even in complex working environments, making them particularly suitable for high-speed, high-temperature operating conditions.

[0009] Furthermore, the object of the present invention can also be achieved by a bearing assembly having a sealing component as described above. This sealing component is disposed between the bearing rings of the bearing assembly for dynamic sealing, preventing grease leakage from the bearing and also preventing external impurities from entering the bearing contents. Attached Figure Description

[0010] Preferred embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0011] Figure 1 It is a cross-sectional view of the sealing assembly of a bearing device based on existing technology;

[0012] Figure 2This is a cross-sectional view of a sealing assembly according to a first embodiment of the present invention;

[0013] Figure 3 This is a cross-sectional view of a sealing assembly according to a second embodiment of the present invention.

[0014] In the figures, the same reference numerals indicate components with the same or similar functions. The directions such as "axial" and "radial" used in this invention are relative to the bearing. Radial outward / radial outer side refers to the direction radially away from the bearing assembly; radial inward / radial inner side refers to the direction radially toward the interior of the bearing assembly; axial inner side refers to the direction axially toward the interior of the bearing assembly; and axial outer side refers to the direction axially toward the exterior of the bearing. Detailed Implementation

[0015] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0016] Figure 1 A cross-sectional view of a bearing assembly sealing component in the prior art is shown. The bearing assembly includes a first component 1 and a second component 2. The first component 1 and the second component 2 rotate relative to each other, and a sealing assembly 3 is provided between the first component 1 and the second component 2. The sealing assembly 3 has a first sealing body 31 fixed to the first component 1 and a second sealing body 32 fixed to the second component 2. The bearing assembly according to the invention is preferably installed on a hub drive system, therefore the relative movement between the first sealing body 31 and the second sealing body 32 is generally relatively fast. A receiving cavity is formed between the first sealing body 31 and the second sealing body 32, within which the first sealing body 31 has a contact lip 33 that forms a contact seal with the second sealing body 32, for better preventing foreign objects from entering the bearing assembly. Figure 1 (Left side blank). However, due to the high-speed relative movement between the first sealing body 31 and the second sealing body 32, the contact lip will generate a large frictional torque, which will affect the rotation of the bearing device and reduce the life of the sealing assembly 3. Therefore, how to ensure the sealing requirements are met while minimizing the contact lip is the core technical problem to be solved by this invention.

[0017] The present invention addresses this technical problem by having a first sealing body 31 with first receiving portions 311 and 312, and a second sealing body 32 with second receiving portions 321 and 322. The first and second receiving portions 311 and 312, and the second receiving portions 321 and 322, together form an annular receiving cavity 35 in a non-contact manner. A magnetic fluid 36 is filled within this annular receiving cavity 35. The first or second sealing body 31 has magnetic elements 34 and 37 for holding the magnetic fluid 36 within the annular receiving cavity 35 by magnetic force. By using magnetic elements 34 and 37, either within or outside the annular receiving cavity 35, the magnetic fluid 36 can be held between the first and second receiving portions 311 and 312, and the second receiving portions 321 and 322, thereby replacing the contact lip 33 to form a non-contact dynamic seal between the first and second sealing bodies 31 and 32. Two specific embodiments of the sealing assembly 3 are given below. However, those skilled in the art should understand that the first receiving portion 311, 312 and the second receiving portion 321, 322 of the sealing assembly 3 can have many more configurations, and are not limited to the specific shapes in the two embodiments given below.

[0018] Figure 2A cross-sectional view of a sealing assembly 3 according to a first embodiment of the present invention is shown. The sealing assembly 3 is composed of a first sealing body 31 and a second sealing body 32. The first sealing body 31 has a first receiving portion 311, and the second sealing body 32 has a second receiving portion 321. In this embodiment, the second receiving portion 321 is made of a rubber body with an axial cross-section in the shape of an open bottle, the bottle cavity forming an annular receiving cavity 35, and the first receiving portion 311 extends into the second receiving portion 321. A magnetic fluid 36 is contained in the second receiving portion 321, and a magnetic element 34 is fixed to the outside of the sealing assembly 3 to fix the magnetic fluid 36 within the bottle cavity formed by the second receiving portion 321, thereby forming a non-contact dynamic seal between the first receiving portion 311 and the second receiving portion 321. The magnetic fluid 36 is preferably a grease containing a magnetic material, such as a grease containing iron powder particles. This grease fills the bottle-shaped cavity formed by the second receiving portion 321 and is attracted by the magnetic element 34. The bottle-shaped chamber reduces the diffusion of the magnetic fluid 36, and even if a small amount of grease is lost during prolonged operation, the grease at the bottom can replenish the neck. This grease completely separates the environment from the bearing cavity, achieving superior sealing performance. In this sealing assembly, all sealing lips 313 are non-contact lips. The only contact material is the grease with magnetic material extending from the first receiving portion 311 into the second receiving portion 321, ensuring a very low frictional torque. The grease completely separates the environment from the bearing cavity, providing superior sealing performance. Preferably, the sealing assembly 3 has a magnetic encoder that incorporates a magnetic element 34. The magnetic encoder detects magnetic signals, providing them to a sensor to detect wheel speed, and is itself magnetic, attracting the magnetic fluid 36. The magnetic component of the encoder is close to or abuts against the second receiving portion 321 of the second seal 32, eliminating the need for a separate magnetic element outside the annular receiving cavity 35, reducing the number of components and lowering costs.

[0019] Figure 3 A cross-sectional view of a sealing assembly according to a second embodiment of the present invention is shown. The sealing assembly 3 is composed of a first sealing body 31 and a second sealing body 32. The first sealing body 31 has a first receiving portion 312, and the second sealing body 32 has a second receiving portion 322. In this embodiment, as... Figure 3As shown, the first receiving portion 312 and the second receiving portion 322 form a receiving space using their respective shapes. A magnetic component 37 is placed in this receiving space, and a magnetic fluid 36 is filled within it. The magnetic fluid 36 is fixed within the receiving space by the magnetic component 37. The second receiving portion 322 is part of the metal skeleton of the second sealing body 32, for example, it is an L-shaped portion of the metal skeleton. The first receiving portion 312 extends two non-contact sealing lips 314, forming a receiving space with the L-shaped second receiving portion 322. The magnetic component 37 can be adsorbed onto the L-shaped metal skeleton. Preferably, the magnetic component 37 is fixed to a stationary sealing body, thereby avoiding the influence of centrifugal force on the magnetic component 37. The grease contains components that attract magnetic materials, making it attractive to magnetic materials. The magnetic fluid 36 is preferably a grease containing magnetic materials, such as a grease containing iron powder particles. This grease fills the receiving cavity formed by the second receiving portion 322 and the first receiving portion 312 and is attracted and held by the magnetic component 37. The radial dimension of the magnetic component 37 gradually increases along the axial direction. For example... Figure 3 As shown, the magnetic component 37 has a stepped ramp structure, which ensures that even with minor grease loss during prolonged operation, the grease on the upper part of the ramp can replenish the lower part. During operation, the magnetic fluid 36, under the influence of centrifugal force, can also move better along the radial direction of the ramp to seal the radially outer gap and prevent external impurities from entering the annular cavity. Alternatively, the magnetic component 37 can be implemented by the second receiving portion 322, which is itself magnetic. Therefore, the second receiving portion 322 can also be designed with a radial dimension that gradually increases along the axial direction, thus eliminating the need for a separate magnetic component 37. In this sealing assembly 3, all sealing lips are non-contact lips. The only contact material is the grease and the sealing lip 314, ensuring that this seal has a very low frictional torque.

[0020] While possible embodiments have been described exemplarily in the foregoing description, it should be understood that numerous variations of embodiments exist through combinations of all known and readily conceived technical features and implementation methods. Furthermore, it should be understood that the exemplary embodiments are merely examples and do not in any way limit the scope, application, or construction of the invention. For instance, the specific shapes of the first and second receiving portions can also be varied in many ways. The foregoing description is more of a technical guide for those skilled in the art to transform at least one exemplary embodiment, wherein various changes can be made, particularly regarding the function and structure of the components, without departing from the scope of the claims.

[0021] List of reference numerals

[0022] 1 First Component

[0023] 2 Second Component

[0024] 3 Sealing components

[0025] 31 First sealing body

[0026] 311, 312 First Containment Department

[0027] 313, 314 Sealing Lid

[0028] 32 Second sealing body

[0029] 321, 322 Second Containment Department

[0030] 33 Contact lips

[0031] Magnetic components 34 and 37

[0032] 35 Annular Reception Cavity

[0033] 36 Magnetic Fluids

Claims

1. A sealing assembly (3) for forming a dynamic seal between a first component (1) and a second component (2), wherein, The sealing assembly (3) includes a first sealing body (31) for fixing to the first component and a second sealing body (32) for fixing to the second component. The first sealing body (31) has a first receiving portion (311, 312), and the second sealing body (32) has a second receiving portion (321, 322). The first receiving portion (311, 312) and the second receiving portion (321, 322) together form an annular receiving cavity (35) in a non-contact manner. The annular receiving cavity (35) is used to fill magnetic fluid (36). The first sealing body (31) or the second sealing body (32) has magnetic elements (34, 37) for holding the magnetic fluid (36) in the annular receiving cavity (35) by magnetic force.

2. The sealing assembly (3) according to claim 1, characterized in that, The axial section (321) of the second receiving part (321) is in the shape of an open bottle, and the first receiving part (311) extends into the opening formed by the second receiving part (321).

3. The sealing assembly (3) according to claim 2, characterized in that, The magnetic component (34) is fixed outside the annular receiving cavity (35).

4. The sealing assembly (3) according to claim 3, characterized in that, The sealing assembly (3) has a magnetic encoder, and the magnetic element (34) is a component implementation of the magnetic encoder.

5. The sealing assembly (3) according to claim 3, characterized in that, The first receiving section (311) and the second receiving section (321) are made of rubber material.

6. The sealing assembly (3) according to claim 1, characterized in that, The second receiving portion (322) has an L-shaped shape, and the first receiving portion (312) includes two sealing lips (314) facing the second receiving portion (322) and together with the L-shaped second receiving portion (322) forms the annular receiving cavity (35).

7. The sealing assembly (3) according to claim 6, characterized in that, The magnetic component (37) is fixed inside or by the second receiving part (322).

8. The sealing assembly (3) according to claim 7, characterized in that, If the magnetic element (37) is fixed inside the second receiving portion (322), the radial dimension of the magnetic element (37) gradually increases along the axial direction; if the magnetic element (37) is implemented by the second receiving portion (322), the radial dimension of the second receiving portion (322) gradually increases along the axial direction.

9. The sealing assembly (3) according to any one of claims 1 to 8, characterized in that, The magnetic fluid (36) is a grease containing magnetic particles.

10. A bearing assembly, characterized in that, The bearing assembly has a sealing component (3) according to any one of claims 1 to 9.

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