Dynamic seal assembly and hub bearing

Abstract

The invention relates to the technical field of vehicle charging, in particular to a dynamic seal assembly and a hub bearing. The dynamic sealing assembly comprises a first sealing unit and a second sealing unit. The first sealing unit comprises an inner framework part, a first sealing ring, a first sealing lip, a second sealing lip and a third sealing lip, and the inner framework part is embedded in the first sealing ring. The third sealing lip, the first sealing lip and the second sealing lip are integrally formed with the first sealing ring, the sealing effect is weakened in sequence, and an ordered abutting force gradient can be formed. The second sealing unit comprises an outer framework part and a second sealing ring. When the movable sealing assembly is in the assembled state, the first sealing ring abuts against the outer framework part. The hub bearing comprises a dynamic sealing assembly, an inner ring assembly, an outer ring assembly and a rolling assembly. The second sealing unit in the dynamic sealing assembly can rotate along with rotation of the inner ring unit, and therefore the dynamic sealing effect is achieved. In this way, the problems that a dynamic sealing assembly is prone to sealing failure and poor in abrasion resistance are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle charging, and in particular to a dynamic sealing assembly and a wheel hub bearing. Background Art

[0002] Dynamic seals are often used on automobile wheel hub bearings because they can rotate with the high-speed rotation of the bearing, thereby maintaining the relative stability of the sealing space to achieve a better sealing effect. Common seals require a large clamping force to ensure sealing, so a supporting frame or a contact point of the seal is added to the inside of the seal. At the same time, as the clamping force increases, the friction between the seal and the bearing will also increase, causing the seal to wear and affect the sealing. For this reason, common designs often optimize the materials of the seal or the seal frame, select more wear-resistant materials or thicken the seal. There are also solutions to improve the structure and adopt multi-layer sealing, but the interaction between its sealing and wear is still a difficult problem to solve.

[0003] The sealing performance and wear degree of the wheel hub bearing affect each other, and it is difficult to find a balance between them with the existing technology, so that the sealing ring has good sealing performance and a certain wear resistance. Therefore, it is necessary to improve the structure of the sealing ring. Summary of the invention

[0004] In order to solve the problems of easy seal failure and poor wear resistance of dynamic seal components in conventional wheel hub bearings, the present invention provides a dynamic seal component and a wheel hub bearing.

[0005] In a first aspect, the present invention provides a dynamic seal assembly, the dynamic seal assembly comprising: A first sealing unit, the first sealing unit comprises an inner frame portion, a first sealing ring, a first sealing lip, a second sealing lip and a third sealing lip; the inner frame portion, the first sealing ring, the first sealing lip, the second sealing lip and the third sealing lip are all annular and coaxial; the inner frame portion comprises a first inner frame and a second inner frame, the second inner frame and the first inner frame are integrally formed; the first inner frame is embedded in the first sealing ring; the diameter of the second inner frame gradually increases in a direction away from the first inner frame; the first sealing lip, the second sealing lip and the third sealing lip are respectively integrally formed with the first sealing ring; the axis of the first sealing ring is perpendicular to a reference plane; the reference plane is located between the first sealing lip and the second sealing lip; the diameter of the first sealing lip gradually decreases in a direction away from the reference plane; the second sealing lip and the third sealing lip are located on the same side of the reference plane; the diameter of the third sealing lip gradually increases in a direction away from the reference plane; the maximum diameter of the second sealing lip is smaller than the minimum diameter of the third sealing lip; the second inner frame is embedded in the third sealing lip; A second sealing unit, the second sealing unit comprises an outer frame portion and a second sealing ring; the outer frame portion and the second sealing ring are both annular; the outer frame portion comprises a first outer frame portion and a second outer frame portion; the first outer frame portion is embedded in the second sealing ring; the projections of the first outer frame portion and the first inner frame portion along the axial direction overlap; the second outer frame portion is integrally formed with the inner circumferential surface of the first outer frame portion; Wherein, when the dynamic seal assembly is in an assembled state, the first sealing lip and the second sealing lip abut against the second outer frame, and the third sealing lip abuts against the first outer frame.

[0006] In some embodiments, the radial thickness of the second inner skeleton gradually decreases in a direction away from the first inner skeleton.

[0007] In some embodiments, the taper of the second inner skeleton gradually increases in a direction away from the first inner skeleton.

[0008] In some embodiments, the taper of the second sealing lip is smaller than the taper of the first sealing lip.

[0009] In some embodiments, a radial thickness of the second sealing lip is greater than a radial thickness of the first sealing lip.

[0010] In some embodiments, the radial thickness of the third sealing lip is greater than the radial thickness of the first sealing lip; the radial thickness of the third sealing lip is less than the radial thickness of the second sealing lip.

[0011] In some embodiments, a buffer groove is formed on a side of the second sealing lip facing away from the second outer skeleton.

[0012] In some embodiments, the dynamic sealing assembly further includes a first grease ring and a second grease ring; when the dynamic sealing assembly is in an assembled state, the first grease ring is filled between the second sealing lip and the third sealing lip; the second grease ring is filled between the first sealing lip and the second sealing lip, and the volume of the first grease ring is greater than that of the second grease ring.

[0013] In some embodiments, the first sealing unit also includes a fourth sealing lip, which is integrally formed with the first sealing ring; the fourth sealing lip and the third sealing lip are located on the same side of the reference plane; the diameter of the fourth sealing ring gradually increases in a direction away from the first sealing ring.

[0014] In a second aspect, the present invention provides a wheel hub bearing, the wheel hub bearing comprising any one of the dynamic seal assemblies in the first aspect, the wheel hub bearing further comprising: An inner ring assembly, the inner ring assembly comprising a first inner ring body, an inner ring flange and a second inner ring body; the first inner ring body and the inner ring flange are integrally formed; the second inner ring body is detachably connected to the first inner ring body; An outer ring assembly, the outer ring assembly comprising an outer ring body and an outer ring flange; the outer ring body and the outer ring flange are integrally formed; the first inner ring body is located inside the outer ring body; the inner ring flange is located outside the outer ring body; the dynamic seal assembly is located between the second inner ring body and the outer ring body; the first sealing unit of the dynamic seal assembly is detachably connected to the outer ring body; the second sealing unit of the dynamic seal assembly is detachably connected to the second inner ring body; Rolling assembly; the inner ring assembly and the outer ring assembly are rotationally connected via the rolling assembly; the first sealing lip of the dynamic sealing assembly is located on the side of the second sealing lip facing the rolling assembly.

[0015] In order to solve the problem that the dynamic seal assembly has easy seal failure and poor wear resistance, the present invention has the following advantages: On the basis of multi-layer sealing, the shape and position of the first sealing lip, the second sealing lip and the third sealing lip are designed so that the sealing effects of the third sealing lip, the first sealing lip and the second sealing lip are weakened in sequence, and an orderly pressing force gradient can be formed, so that the grease can better lubricate and dissipate heat for the three sealing lips inside the third sealing lip and is not easy to leak, and the grease inside the second sealing lip can be appropriately supplemented to the outside to achieve the effect of dynamic balance of grease. The first sealing lip and the second sealing lip are small in size and compact in structure, which improves the tightness of the dynamic sealing assembly and improves the sealing performance. By improving the structure of the sealing assembly, it is divided into different functional areas, thereby complementing each other's defects, so that the dynamic sealing assembly can achieve a balance between sealing and wear resistance to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of a hub bearing according to an embodiment is shown; Figure 2 Shows Figure 1 The enlarged view of part A in the figure is used to illustrate the dynamic seal assembly.

[0017] Figure markings: 10 dynamic sealing assembly; 11 first sealing unit; 111 inner skeleton; 1111 first inner skeleton; 1112 second inner skeleton; 1113 third inner skeleton; 112 first sealing ring; 113 first sealing lip; 114 second sealing lip; 115 third sealing lip; 116 cache groove; 117 fourth sealing lip; 12 second sealing unit; 121 outer skeleton; 1211 first outer skeleton; 1212 second outer skeleton; 1213 third outer skeleton; 122 second sealing ring; 20 inner ring assembly; 201 first inner ring body; 202 inner ring flange; 203 second inner ring body; 30 outer ring assembly; 301 outer ring body; 302 outer ring flange; 40 rolling assembly. DETAILED DESCRIPTION

[0018] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, rather than implying any limitation on the scope of the present disclosure.

[0019] As used herein, the term "including" and its variants are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal" and the like is based on the orientation or position relationship shown in the accompanying drawings. These terms are mainly for better describing the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation. In addition, in addition to being used to indicate an orientation or position relationship, some of the above terms may also be used to indicate other meanings, such as the term "upper" may also be used to indicate a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to the specific circumstances. In addition, the terms "install", "set", "provided with", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or it can be an internal connection between two devices, elements or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0020] The dynamic seal assembly 10 commonly used in wheel hub bearings needs to have sufficient clamping force to ensure its sealing performance. The increase in clamping force will cause more wear, and the wear of the seal assembly will lead to a decrease in sealing performance. A common design is to optimize the material or structure of the seal assembly, select more wear-resistant materials, increase the sealing frame or increase the sealing points, which can improve the sealing performance and wear resistance to a certain extent, but there is no obvious effect on the balance between the two. In this regard, a dynamic seal assembly 10 is disclosed in this embodiment, such as Figure 2 As shown, the dynamic sealing assembly 10 may include a first sealing unit 11 and a second sealing unit 12 .

[0021] The first sealing unit 11 includes an inner skeleton portion 111, a first sealing ring 112, a first sealing lip 113, a second sealing lip 114 and a third sealing lip 115. The inner skeleton portion 111, the first sealing ring 112, the first sealing lip 113, the second sealing lip 114 and the third sealing lip 115 are all annular and coaxial. The inner skeleton portion 111 includes a first inner skeleton 1111 and a second inner skeleton 1112, and the second inner skeleton 1112 is integrally formed with the first inner skeleton 1111. The first inner skeleton 1111 is embedded in the first sealing ring 112, and the existence of the first inner skeleton 1111 can improve the rigidity of the first sealing ring 112. The diameter of the second inner skeleton 1112 gradually increases in the direction away from the first inner skeleton 1111. In this embodiment, the inner skeleton portion 111 also includes a third inner skeleton 1113, and the third inner skeleton 1113 is integrally formed with the inner circumferential surface of one end of the first inner skeleton 1111 close to the outer ring unit 30. The first sealing lip 113, the second sealing lip 114 and the third sealing lip 115 are respectively formed integrally with the first sealing ring 112, so that the sealing effect of the first sealing ring 112 can be strengthened layer by layer. The axis of the first sealing ring 112 is perpendicular to the reference plane, and the reference plane is located between the first sealing lip 113 and the second sealing lip 114. The diameter of the first sealing lip 113 gradually decreases in the direction away from the reference plane. The second sealing lip 114 and the third sealing lip 115 are located on the same side of the reference plane, and the first sealing lip 113 is located on the other side. The first sealing lip 113 is the one closest to the innermost side of the hub bearing. When the rolling body generates heat during operation and causes the grease to expand, the pressure generated by the grease is perpendicular to the extension direction of the first sealing lip 113, so that the greater the internal pressure of the chamber where the rolling body is located, the greater the force of the sealing lip pressing toward the inner ring of the bearing, so that the sealing effect is better and it is not easy to cause a large amount of oil leakage. The diameter of the second sealing lip 114 gradually decreases in the direction away from the reference plane, and the maximum diameter of the second sealing lip 114 can be smaller than the minimum diameter of the third sealing lip 115, so that when the grease in the cavity between the first sealing lip 113 and the second sealing lip 114 reaches a certain amount, the pressure generated by the grease can easily push the end of the second sealing lip 114 away from the first sealing lip 113 to relieve pressure. In addition, the grease flows from the cavity between the first sealing lip 113 and the second sealing lip 114 to the cavity between the second sealing lip 114 and the third sealing lip 115 to make up for the leakage of grease between the second sealing lip 114 and the third sealing lip 115, and the cavity between the second sealing lip 114 and the third sealing lip 115 is larger and has more grease, thereby improving the heat dissipation and lubrication effect of the dynamic seal assembly 10. The diameter of the third sealing lip 115 gradually increases in the direction away from the reference plane. The second inner frame 1112 is embedded in the third sealing lip 115, so that the strength and bending resistance of the third sealing lip 115 can be improved.

[0022] The second sealing unit 12 includes an outer skeleton portion 121 and a second sealing ring 122. The outer skeleton and the second sealing ring 122 are both annular. The outer skeleton portion 121 includes a first outer skeleton 1211 and a second outer skeleton 1212, and the first outer skeleton 1211 is embedded in the second sealing ring 122. The projections of the first outer skeleton 1211 and the first inner skeleton 1111 along the axial direction partially overlap, so that the first sealing unit 11 and the second sealing unit 12 partially overlap, and the two cooperate to achieve the sealing of the oil in the chamber where the rolling body is located. The second outer skeleton 1212 is integrally formed with the inner circumference of the first outer skeleton 1211, so that Figure 2 As shown, the cross-sections of both are L-shaped.

[0023] Among them, when the dynamic seal assembly 10 is assembled, the third inner frame 1113 abuts against the outer ring unit 30, the first sealing lip 113 and the second sealing lip 114 abut against the second outer frame 1212, and the third sealing lip 115 abuts against the first outer frame 1211. The third sealing lip 115 is embedded with the second inner frame 1112, so that the rigidity of the third sealing lip 115 is improved, thereby increasing the abutting force of the third sealing lip 115 on the first outer frame 1211, so that the sealing effect of the third sealing lip 115 is the best, impurities are not easily invaded, and a better seal for grease is achieved.

[0024] Thus, the sealing effects of the third sealing lip 115, the first sealing lip 113 and the second sealing lip 114 are weakened in sequence, and an orderly pressing force gradient can be formed, which has a good anti-wear effect, and the grease can be well lubricated and dissipated for the three sealing lips in the chamber formed between the second sealing ring 122 and the third sealing ring without leaking easily, and the grease between the second sealing lip 114 and the first sealing lip 113 can be appropriately supplemented to the outside to achieve the effect of dynamic balance of the grease. The first sealing lip 113 and the second sealing lip 114 are small in size and compact in structure, which improves the tightness of the dynamic seal assembly 10 and improves the sealing performance.

[0025] In another embodiment, the exoskeleton portion 121 may further include a third exoskeleton 1213 , and the third exoskeleton 1213 may be integrally formed with the inner circumferential surface of the first exoskeleton 1211 at one end away from the second exoskeleton 1212 , thereby blocking most pollutants from intruding.

[0026] In this embodiment, if Figure 2As shown, the radial thickness of the second inner skeleton 1112 can gradually decrease in the direction away from the first inner skeleton 1111, thereby avoiding to a certain extent the excessive strength and rigidity of the third sealing lip 115 and the resulting excessive clamping force on the first outer skeleton 1211. Therefore, the second inner skeleton 1112 structure with a gradually decreasing thickness can make the strength and rigidity of the third sealing lip 115 at an optimal level, which can not only ensure a better clamping force to achieve sealing, but also avoid the clamping force exceeding a certain level causing excessive wear during operation, resulting in premature failure of the third sealing lip 115. Therefore, this embodiment can increase the life of the third sealing lip 115.

[0027] In this embodiment, if Figure 2 As shown, the taper of the second inner skeleton 1112 can gradually increase in the direction away from the first inner skeleton 1111, that is, the second inner skeleton 1112 is Figure 2 The cross-sectional profile in the figure is curved. The second inner frame 1112 is a hard support structure in the third sealing lip 115. The increase in its taper can further maintain the vertical force of the third sealing lip 115 on the second outer frame 1212, that is, the pressing force, within a certain range, thereby avoiding premature failure of the third sealing lip 115. In addition, while the second inner frame 1112 provides rigidity and strength for the third sealing lip 115, the structure of the second inner frame 1112 with a gradually changing taper can also provide a certain avoidance space for the appropriate elastic deformation of the third sealing lip 115, thereby avoiding internal interference failure.

[0028] In this embodiment, if Figure 2 As shown, the taper of the second sealing lip 114 can be smaller than the taper of the first sealing lip 113, so as to further reduce the pressing force of the second sealing lip 114 on the second outer frame 1212, avoid excessive wear, and at the same time improve the dynamic replenishment effect of grease between the second sealing lip 114 and the third sealing lip 115, thereby ensuring that there is sufficient grease in the cavity between the second sealing lip 114 and the third sealing lip 115 to achieve better heat dissipation and lubrication effects.

[0029] In this embodiment, if Figure 2 As shown, the radial thickness of the second sealing lip 114 can be greater than the radial thickness of the first sealing lip 113, so that the second sealing lip 114 has better wear resistance. Even in the case that the third sealing lip 115 fails, based on the shape characteristics of the second sealing lip 114, the second sealing lip 114 can achieve a higher sealing effect and is not easily invaded by external sewage.

[0030] In this embodiment, if Figure 2As shown, the radial thickness of the third sealing lip 115 can be greater than the radial thickness of the first sealing lip 113, and the radial thickness of the third sealing lip 115 can be less than the radial thickness of the second sealing lip 114. The thicknesses of the three form a certain gradient, matching the pressing force gradient of the three. The third sealing lip 115, as the first-level seal to prevent external pollution from invading, can ensure a certain degree of wear resistance and elasticity, and increase the service life.

[0031] In this embodiment, if Figure 2 As shown, a cache groove 116 may be formed on one side of the second sealing lip 114 away from the second outer frame 1212. The cache groove 116 is located in the chamber between the second sealing lip 114 and the third sealing lip 115, and the curved inner wall of the cache groove 116 may be used to cache more grease. In addition, the structural design of the cache groove 116 increases the contact area between the grease and the second sealing lip 114, thereby improving the heat dissipation effect of the second sealing lip 114.

[0032] In this embodiment, if Figure 2 As shown, the dynamic seal assembly 10 also includes a first grease ring and a second grease ring; when the dynamic seal assembly 10 is assembled, the first grease ring is filled between the second sealing lip 114 and the third sealing lip 115, and the second grease ring is filled between the first sealing lip 113 and the second sealing lip 114, and the volume of the first grease ring is greater than that of the second grease ring. The chamber between the second sealing lip 114 and the third sealing lip 115 is larger than the chamber between the first sealing lip 113 and the second sealing lip 114, and the wear path of the third sealing lip 115 is longer. Increasing the grease between the second sealing lip 114 and the third sealing lip 115 helps to improve the lubricity and heat dissipation of the third seal, and helps to reduce wear and increase service life.

[0033] In this embodiment, the first sealing unit 11 may further include a fourth sealing lip 117. The fourth sealing lip 117 is integrally formed with the first sealing ring 112. The fourth sealing lip 117 and the third sealing lip 115 are located on the same side of the reference plane, and the diameter of the fourth sealing ring gradually increases in the direction away from the first sealing ring 112. The fourth sealing lip 117 is closer to the external space than the third sealing lip 115, and can block most of the external pollutants before the third sealing lip 115, while reducing the possibility of the third sealing lip 115, which mainly plays a sealing role, being corroded and failing due to contamination, thereby increasing the service life of the first sealing ring 112.

[0034] In this embodiment, a wheel hub bearing is disclosed. The wheel hub bearing includes the dynamic seal assembly 10 in any of the above embodiments, such as Figure 1 As shown, the wheel hub bearing further includes an inner ring assembly 20 , an outer ring assembly 30 and a rolling assembly 40 .

[0035] The inner ring assembly 20 includes a first inner ring body 201, an inner ring flange 202 and a second inner ring body 203; the first inner ring body 201 and the inner ring flange 202 are integrally formed, and the second inner ring body 203 is detachably connected to the first inner ring body 201. The inner ring flange 202 is used to be detachably connected to a brake disc on a vehicle. The outer ring assembly 30 includes an outer ring body 301 and an outer ring flange 302; the outer ring body 301 and the outer ring flange 302 are integrally formed, and the outer ring flange 302 is used to be detachably connected to a suspension on a vehicle. The first inner ring body 201 is located inside the outer ring body 301, and the inner ring flange 202 is located outside the outer ring body 301.

[0036] The dynamic seal assembly 10 is located between the second inner ring body 203 and the outer ring body 301. The first sealing unit 11 of the dynamic seal assembly 10 is detachably connected to the outer ring body 301, and the second sealing unit 12 of the dynamic seal assembly 10 is detachably connected to the second inner ring body 203. The second sealing unit 12 in the dynamic seal assembly 10 can rotate with the rotation of the inner ring unit, thereby achieving a dynamic sealing effect.

[0037] The inner ring assembly 20 and the outer ring assembly 30 are rotatably connected through the rolling assembly 40. The rolling assembly 40 is provided with two groups, one of which is located between the second inner ring body 203 and the outer ring body 301, and the other is located between the first inner ring body 201 and the outer ring body 301. The first sealing lip 113 of the dynamic seal assembly 10 is located on the side of the second sealing lip 114 facing the rolling assembly 40, so that the first sealing lip 113 can prevent the oil leakage in the chamber where the rolling assembly 40 is located.

[0038] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made thereto in form and detail without departing from the scope of the present disclosure.

Claims

1. A dynamic sealing assembly, characterized in that: The dynamic seal assembly comprises: A first sealing unit, the first sealing unit comprises an inner frame portion, a first sealing ring, a first sealing lip, a second sealing lip and a third sealing lip; the inner frame portion, the first sealing ring, the first sealing lip, the second sealing lip and the third sealing lip are all annular and coaxial; the inner frame portion comprises a first inner frame and a second inner frame, the second inner frame and the first inner frame are integrally formed; the first inner frame is embedded in the first sealing ring; the diameter of the second inner frame gradually increases in a direction away from the first inner frame; the first sealing lip, the second sealing lip and the third sealing lip are respectively integrally formed with the first sealing ring; the axis of the first sealing ring is perpendicular to a reference plane; the reference plane is located between the first sealing lip and the second sealing lip; the diameter of the first sealing lip gradually decreases in a direction away from the reference plane; the second sealing lip and the third sealing lip are located on the same side of the reference plane; the diameter of the third sealing lip gradually increases in a direction away from the reference plane; the maximum diameter of the second sealing lip is smaller than the minimum diameter of the third sealing lip; the second inner frame is embedded in the third sealing lip; A second sealing unit, the second sealing unit comprises an outer frame portion and a second sealing ring; the outer frame portion and the second sealing ring are both annular; the outer frame portion comprises a first outer frame portion and a second outer frame portion; the first outer frame portion is embedded in the second sealing ring; the projections of the first outer frame portion and the first inner frame portion along the axial direction overlap; the second outer frame portion is integrally formed with the inner circumferential surface of the first outer frame portion; Wherein, when the dynamic seal assembly is in an assembled state, the first sealing lip and the second sealing lip abut against the second outer frame, and the third sealing lip abuts against the first outer frame.

2. A dynamic seal assembly according to claim 1, characterized in that: The radial thickness of the second inner skeleton gradually decreases in a direction away from the first inner skeleton.

3. A dynamic seal assembly according to claim 2, characterized in that: The taper of the second inner skeleton gradually increases in a direction away from the first inner skeleton.

4. A dynamic seal assembly according to claim 1, characterized in that: The taper of the second sealing lip is smaller than the taper of the first sealing lip.

5. A dynamic seal assembly according to claim 4, characterized in that: A radial thickness of the second sealing lip is greater than a radial thickness of the first sealing lip.

6. A dynamic seal assembly according to claim 5, characterized in that: The radial thickness of the third sealing lip is greater than the radial thickness of the first sealing lip; the radial thickness of the third sealing lip is less than the radial thickness of the second sealing lip.

7. A dynamic seal assembly according to claim 6, characterized in that: A buffer groove is formed on a side of the second sealing lip away from the second outer frame.

8. A dynamic seal assembly according to claim 1, characterized in that: The dynamic seal assembly also includes a first grease ring and a second grease ring; when the dynamic seal assembly is in an assembled state, the first grease ring is filled between the second sealing lip and the third sealing lip; the second grease ring is filled between the first sealing lip and the second sealing lip, and the volume of the first grease ring is greater than that of the second grease ring.

9. A dynamic seal assembly according to claim 8, characterized in that: The first sealing unit also includes a fourth sealing lip, which is integrally formed with the first sealing ring; the fourth sealing lip and the third sealing lip are located on the same side of the reference plane; the diameter of the fourth sealing ring gradually increases in a direction away from the first sealing ring.

10. A wheel hub bearing, characterized in that: The wheel hub bearing comprises: The dynamic sealing assembly according to any one of claims 1 to 9; An inner ring assembly, the inner ring assembly comprising a first inner ring body, an inner ring flange and a second inner ring body; the first inner ring body and the inner ring flange are integrally formed; the second inner ring body is detachably connected to the first inner ring body; An outer ring assembly, the outer ring assembly comprising an outer ring body and an outer ring flange; the outer ring body and the outer ring flange are integrally formed; the first inner ring body is located inside the outer ring body; the inner ring flange is located outside the outer ring body; the dynamic seal assembly is located between the second inner ring body and the outer ring body; the first sealing unit of the dynamic seal assembly is detachably connected to the outer ring body; the second sealing unit of the dynamic seal assembly is detachably connected to the second inner ring body; Rolling assembly; the inner ring assembly and the outer ring assembly are rotationally connected via the rolling assembly; the first sealing lip of the dynamic sealing assembly is located on the side of the second sealing lip facing the rolling assembly.

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