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CN-121993500-A - Seal assembly and bearing device

CN121993500ACN 121993500 ACN121993500 ACN 121993500ACN-121993500-A

Abstract

The invention relates to a seal assembly for forming a dynamic seal between a first component and a second component, wherein the seal assembly comprises a first seal body for fixing to the first component and a second seal body for fixing to the second component, wherein the first seal body has a first receiving portion and the second seal body has a second receiving portion, which together form an annular receiving cavity in a non-contact manner, wherein the annular receiving cavity is used for filling magnetic fluid, and the first seal body or the second seal body has a magnetic element for holding the magnetic fluid in the annular receiving cavity by magnetic force, so that the first seal body and the second seal body form a non-contact dynamic seal to replace a contact lip between the first seal body and the second seal body.

Inventors

  • LIU XIN
  • ZHANG YUELIN

Assignees

  • 舍弗勒技术股份两合公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. A seal assembly (3) for forming a dynamic seal between a first component (1) and a second component (2), wherein the seal assembly (3) comprises a first seal body (31) for fixing to the first component and a second seal body (32) for fixing to the second component, wherein the first seal body (31) has a first receiving portion (311, 312), the second seal 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 contactless manner, wherein the annular receiving cavity (35) is for filling with a magnetic fluid (36), the first seal body (31) or the second seal body (32) has a magnetic element (34, 37) for holding the magnetic fluid (36) within the annular receiving cavity (35) by magnetic force.
  2. 2. The seal assembly (3) according to claim 1, wherein the second receiving portion (321) has an open-ended bottle-like cross-section (321), and the first receiving portion (311) extends into an opening formed by the second receiving portion (321).
  3. 3. The sealing assembly (3) according to claim 2, wherein the magnetic element (34) is fixed outside the annular housing cavity (35).
  4. 4. A seal assembly (3) according to claim 3, wherein the seal assembly (3) has a magnetic encoder, the magnetic member (34) being a component realization of the magnetic encoder.
  5. 5. A seal assembly (3) according to claim 3, wherein the first receiving portion (311) and the second receiving portion (321) are composed of a rubber material.
  6. 6. The sealing assembly (3) according to claim 1, wherein the second housing portion (322) has an L-shape, the first housing portion (312) comprising two sealing lips (314) facing the second housing portion (322) and forming the annular housing cavity (35) with the L-shaped second housing portion (322).
  7. 7. The sealing assembly (3) according to claim 6, wherein the magnetic element (37) is fixed within the second housing (322) or is realized by the second housing (322).
  8. 8. The sealing assembly (3) according to claim 7, wherein if the magnetic element (37) is fixed in the second housing (322), the radial dimension of the magnetic element (37) becomes progressively larger in the axial direction, and if the magnetic element (37) is realized by the second housing (322), the radial dimension of the second housing (322) becomes progressively larger in the axial direction.
  9. 9. The seal assembly (3) according to any one of claims 1 to 8, wherein the magnetic fluid (36) is a grease containing magnetic particles.
  10. 10. Bearing arrangement, characterized in that it has a sealing assembly (3) according to any one of claims 1 to 9.

Description

Seal assembly and bearing device Technical Field The invention relates to a sealing technology, in particular to a dynamic sealing technology, and particularly relates to a sealing assembly for a hub bearing. Bearings in hub drive systems generally use a typical seal assembly structure made of a backbone, rubber, seal lips, mounted between the inner and outer rings of the bearing. Such a seal assembly is used to seal grease inside the bearing and to retain contaminants and muddy water outside the bearing. Background Such conventional seal assemblies are used to prevent contamination and muddy water from entering the bearing. In order to obtain good sealing performance, it is necessary to design a larger sealing lip for sealing contact with the contact surface, or to design more sealing lips to prevent intrusion of external contamination. Therefore, such conventional seal assemblies have a very large sealing friction torque, waste a lot of energy and make the sealing lips susceptible to wear. To address this problem, solutions have been developed in the prior art that utilize a magnet assembly to attract magnetic fluid in place of a contact lip for dynamic sealing, as disclosed in CN 104632899A. A ring magnet is provided between an inner ring and an outer ring of the bearing to hold a magnetic fluid, and a plurality of rolling elements are sealed. However, this solution still has many drawbacks, such as complex structure of the magnet assembly, large space occupation and excessive cost, and the magnetic fluid directly contacts the internal grease and the external environment, which causes the internal grease to be easily polluted, and the magnetic fluid to be easily diffused outwards into the external environment. The magnetic fluid is often diluted by contaminants and loses its sealing function. Disclosure of Invention The object of the present invention is to provide an improved seal assembly which avoids the friction problems associated with contact seals while ensuring that the magnetic fluid of the seal assembly does not readily diffuse, providing a reliable seal in complex operating environments. To achieve the above objects, the present invention provides an improved seal assembly mounted between a first member and a second member for dynamic sealing with relative rotation therebetween. The sealing assembly comprises a first sealing body fixed on the first component and a second sealing body fixed on the second component, wherein the first sealing body is provided with a first accommodating part, the second sealing body is provided with a second accommodating part, and the first accommodating part and the second accommodating part form an annular accommodating cavity in a non-contact mode. The annular accommodating cavity is filled with magnetic fluid, and the first sealing body or the second sealing body is provided with a magnetic piece for keeping the magnetic fluid in the annular accommodating cavity through magnetic force, so that a non-contact dynamic seal is formed between the first sealing body and the second sealing body, and a contact sealing lip is not required to be arranged between the first sealing body and the second sealing body. The design of the non-contact seal effectively solves the friction and abrasion problems caused by the contact lip in the prior art, greatly reduces friction moment and prolongs the service life of the seal assembly. In addition, the annular accommodating cavity formed by the first accommodating part and the second accommodating part can be used for fixing the magnetic fluid inside the sealing assembly, so that the application of the magnetic fluid is more reliable, and the magnetic fluid can be prevented from being diffused into the external environment while external pollutants are effectively prevented from entering the bearing device. In a preferred embodiment of the present invention, the second receiving portion of the second sealing body has an open-ended bottle-shaped axial cross section, 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 receiving the magnetic fluid, and the first receiving portion extends into the bottle cavity, so that a dynamic seal can be formed between the first receiving portion and the second receiving portion by the magnetic fluid. This design can further reduce the diffusion of the magnetic fluid, and in particular, even if there is a small loss of grease during long-term operation, the grease at the bottom of the bottle-shaped cavity can be replenished to the bottleneck portion, thereby ensuring the long-term sealing performance of the bearing device. It is further preferred that the magnetic member is fixed outside the annular receiving cavity. The design of external magnetic part is favorable to avoiding the magnetic part to receive the inside high temperature of annular chamber or the direc