Sealing device and sealing assembly

Abstract

The invention relates to a sealing device and a sealing assembly. The sealing device comprises a rigid annular piece and an elastic sealing ring. The elastic sealing ring is arranged on the radial inner side of the rigid annular piece. The elastic sealing ring comprises a main body part and a main sealing lip. The main body part is fixed to the rigid annular piece, and the main sealing lip is a free end extending from the main body part and is provided with a lip opening used for contact sealing. The main sealing lip is provided with a two-way oil-driven return part located on the radial outer side of a lip opening, the two-way oil-driven return part comprises a pair of protruding arc surfaces relatively close to the surface of the lip opening, and the arc surfaces are arranged in an axial symmetry mode and obliquely extend from the radial inner side to the radial outer side towards the two sides in the circumferential direction respectively. By the adoption of the sealing device, lubricating oil or lubricating grease can be well kept on the surface of the main sealing lip, the sealing performance of the sealing device is improved, the service life of the sealing device is prolonged, and cost is lower.

Description

Technical Field

[0001] The present invention relates to the field of sealing technology, and in particular to a sealing device and a sealing assembly for dynamic sealing. Background Art

[0002] Sealing devices need to be installed in many rotating parts of machinery. In particular, in the field of vehicle wheel bearings, dynamic seals with high sealing performance and low friction torque are required. These sealing devices are usually annular and include an outer rigid annular member, an elastic sealing body and an oil retaining ring; the sealing lips of the elastic sealing body include a dustproof lip, a main lip and a centrifugal lip, and the above-mentioned sealing lips are in sealing contact with the oil retaining ring fixed on the sealed part to perform sealing.

[0003] However, a high friction torque is generated between the sealing lip and the relatively rotating component in a conventional sealing device. In particular, a spring structure is provided on the sealing lip to ensure the sealing performance of the sealing lip, which results in a large contact area between the sealing lip and the relatively rotating component, causing a large amount of energy loss and making the sealing lip easy to wear. Therefore, it is necessary to develop a sealing device with low friction torque. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a sealing device and a sealing assembly.

[0005] In a first aspect, a sealing device is provided according to an embodiment of the present invention, comprising: a rigid annular member and an elastic sealing ring; the elastic sealing ring is arranged on the radial inner side of the rigid annular member. The elastic sealing ring comprises a main body and a main sealing lip. The main body is fixed on the rigid annular member, and the main sealing lip is a free end extending from the main body, and has a lip for contact sealing. Wherein, the main sealing lip is provided with a bidirectional oil drive return portion located radially outside the lip, and the bidirectional oil drive return portion comprises a pair of arc surfaces protruding relatively close to the lip surface, and the pair of arc surfaces are arranged in an axially symmetrical manner, and extend obliquely from the radial inner side to the radial outer side toward both sides of the circumferential direction respectively.

[0006] According to an embodiment of the present invention, the arc surface is perpendicular to the surface close to the lip, and the angle between the pair of arc surfaces and the circumferential direction gradually decreases along both sides.

[0007] According to an embodiment of the present invention, ends on both sides of the pair of arc surfaces are parallel to the circumferential direction.

[0008] According to an embodiment of the present invention, there are a plurality of bidirectional oil drive-back portions, which are evenly distributed on the main sealing lip along the circumferential direction.

[0009] According to an embodiment of the present invention, the side of the bidirectional oil drive back portion facing the main body portion includes a straight surface perpendicular to the main sealing lip surface and parallel to the circumferential direction.

[0010] According to an embodiment of the present invention, the elastic sealing ring is made of rubber material.

[0011] According to an embodiment of the present invention, the main body, the main sealing lip and the bidirectional oil drive back portion are an integrally formed structure.

[0012] According to one embodiment of the present invention, an annular tension spring is provided on a side of the main sealing lip facing away from the surface where the bidirectional oil drive return portion is provided.

[0013] In a second aspect, a sealing assembly is also provided according to an embodiment of the present invention, the sealing assembly comprising a sealing device as described above and an element rotating relative to the sealing device, the lip of the main sealing lip contacts the circumferential surface of the element, and the element is a bearing inner ring, an end cover or a shaft.

[0014] According to an embodiment of the present invention, two sides of the lip in the axial direction are respectively a grease side and an air side, and the bidirectional oil drive back portion is located on the air side.

[0015] By providing a bidirectional oil drive back portion on the main sealing lip, the bidirectional oil drive back portion of the lubricating oil or grease oil seal can produce a pumping oil return effect during the forward and reverse rotation of the shaft. The bidirectional oil drive back portion includes a pair of arc surfaces perpendicular to the surface of the main sealing lip, which can not only prevent the accumulation and dissipation of the lubricating oil or grease, but also maintain a slightly thick oil film on the surface of the main sealing lip, thereby reducing the wear of the main sealing lip and producing suction and oil return effects. In addition, the side of the bidirectional oil drive back portion facing the main body includes a straight surface perpendicular to the surface of the main sealing lip and parallel to the circumferential direction. The straight surface facing the grease side allows the rotating lubricating oil or grease to flow smoothly, and can provide a good guiding effect. In summary, the sealing device of the present invention can keep the lubricating oil or grease well on the surface of the main sealing lip, improve the sealing performance and service life of the sealing device, and have lower cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 A perspective view of a sealing device according to an embodiment of the present invention is shown;

[0018] Figure 2 Shown as Figure 1 A partial enlarged schematic diagram of the elastic sealing ring in the middle A area;

[0019] Figure 3 A partial cross-sectional view showing a sealing device according to an embodiment of the present invention; and

[0020] Figure 4 A partial schematic diagram of an elastic sealing ring according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0022] According to an embodiment of the present invention, a sealing device is provided. The sealing device is used to seal between various rotating parts that need to be sealed, and can be installed between the outer ring and the inner ring of the sealed rotating mechanism (such as a bearing), or between the bearing and the rotating shaft. The sealing device can seal lubricating oil or grease inside, and block pollutants such as muddy water outside.

[0023] Figure 1 FIG. 1 shows a three-dimensional view of a sealing device 1 according to an embodiment of the present invention. The central axis of the sealing device 1 is arranged to substantially coincide with the rotation axis of the bearing. Figure 1 As shown, the sealing device 1 includes: a rigid annular member 11 and an elastic sealing ring 12. The elastic sealing ring 12 is arranged on the radial inner side of the rigid annular member 11, and is used to relatively rotatably contact with the inner ring or the rotating shaft to form an axial rotation seal. The interior of the bearing has lubricating oil or grease, which can wrap the surface of the elastic sealing ring 12, thereby lubricating and protecting the sealing device 1.

[0024] Further, Figure 2 Shown as Figure 1 A partial enlarged schematic diagram of the elastic sealing ring 12 in the middle A area, Figure 3 A partial cross-sectional view of a sealing device 1 according to an embodiment of the present invention is shown. Figure 3 The up-down direction is the axial direction A, and the left-right direction is the radial direction R. The elastic sealing ring 12 is made of rubber material. Figure 2-3As shown, the elastic sealing ring 12 includes a main body 121 and a main sealing lip 122. The main body 121 is fixed to the radial inner side of the rigid annular member 11 by, for example, interference fit, and the main sealing lip 122 is a free end extending from the main body 121 and has a lip 122a for contact sealing. The main sealing lip 122 generally extends in a direction away from the rigid annular member 11. The main sealing lip 122 can be in relatively rotatable contact with the inner ring or the rotating shaft to form an axial rotation seal.

[0025] Figure 4 FIG. 2 shows a partial schematic diagram of an elastic sealing ring according to an embodiment of the present invention. Figure 2-4 As shown, the main sealing lip 122 is provided with a bidirectional oil drive return portion 123 located radially outside the lip opening 122a. The bidirectional oil drive return portion 123 includes a pair of arc surfaces 123a protruding from the surface close to the lip opening 122a. The pair of arc surfaces 123a are arranged in an axisymmetric manner, and extend obliquely from the radial inner side to the radial outer side toward both sides of the circumferential direction C. For example, Figure 4 As shown in FIG. 1 , a pair of arc surfaces 123 a form a symmetrical double-wing structure.

[0026] Optionally, in some embodiments, the arc surface 123a can be arranged perpendicular to the surface near the lip 122a, so as to facilitate the processing and manufacturing of the sealing device. In other embodiments, the arc surface 123a can be arranged at an acute angle with the surface near the lip 122a, so that the arc surface 123a can have a better oil return effect on the lubricating oil or grease. In some other embodiments, the angle of the arc surface 123a relative to the surface of the lip 122a can also be in other forms, such as a curved shape with a gradually changing angle, or a shape in which a straight portion at a certain angle is combined with a curved portion with a gradually changing angle, which is not limited here.

[0027] Furthermore, the angle between the pair of arc surfaces 123a and the circumferential direction C gradually decreases along both sides, that is, the more the pair of arc surfaces 123a extend toward both sides of the circumferential direction C, the smaller the angle between the arc surfaces 123a and the circumferential direction C. In particular, the angle between the direction in which the pair of arc surfaces 123a extend toward both sides and the circumferential direction C gradually becomes 0, that is, the ends of both sides of the pair of arc surfaces 123a gradually become parallel to the circumferential direction C. In this way, the lubricating oil or lubricating grease at the end of the main sealing lip 122 can be better retained at the end of the main sealing lip 122, forming a thicker oil seal, and reducing the lubricating oil or lubricating grease at the end of the main sealing lip 122 from flowing back toward the main body 121.

[0028] In some optional embodiments, there are multiple bidirectional oil drive back parts 123, and they are evenly distributed on the main sealing lip 122 along the circumferential direction C. The number of bidirectional oil drive back parts 123 can be determined according to the size of the sealing device 1. There is an appropriate distance between two adjacent bidirectional oil drive back parts 123, so that the lubricating oil or grease inside the bearing can pass through the gap between the two adjacent bidirectional oil drive back parts 123 from the grease side to the end of the main sealing lip 122; however, if the distance between the two adjacent bidirectional oil drive back parts 123 is too large, it will also cause the lubricating oil or grease at the end of the main sealing lip 122 to be easily lost and flow back to the grease side.

[0029] In some optional embodiments, such as Figure 4 As shown, the surface of the two-way oil drive back portion 123 facing the main body 121 (i.e., the side away from the lip 122a) can be a straight surface 123b perpendicular to the surface of the main sealing lip 122 and parallel to the circumferential direction C, so as to guide a very small amount of lubricating oil or grease thrown out to the side of the two-way oil drive back portion 123 away from the lip 122a to move along the circumferential direction C. The surface of the two-way oil drive back portion 123 facing the main body 121 can also be a surface of other shapes, which is not limited here. It should be understood that the straight surface 123b should have a certain height in the direction perpendicular to the surface of the main sealing lip 122, so as to ensure that the arc surface 123a has a certain height in the direction perpendicular to the surface of the main sealing lip 122, thereby ensuring the arc surface 123a intercepts and guides the lubricating oil or grease near the lip 122a.

[0030] In some optional embodiments, such as Figure 3 As shown, the main body 121 is further provided with an annular secondary sealing lip 124 on one side close to the rigid annular member 11. The secondary sealing lip 124 can further seal the lubricating oil or grease inside the bearing and block pollutants such as muddy water from the outside.

[0031] It should be understood that a bidirectional oil drive return portion may also be provided on the secondary sealing lip 124 , which is similar to the bidirectional oil drive return portion structure in the aforementioned embodiment and will not be described in detail herein.

[0032] In some optional embodiments, the main body 121, the main sealing lip 122 and the two-way oil drive back portion 123 can be an integrally formed structure manufactured by molding. Of course, the main body 121, the main sealing lip 122, the two-way oil drive back portion 123 and the auxiliary sealing lip 124 can also be an integrally formed structure manufactured by molding.

[0033] In some optional embodiments, such as Figure 3As shown, in order to make the main sealing lip 122 fit more closely with the inner ring or the radial inner shaft, an annular tension spring 13 is provided on the side of the main sealing lip 122 facing away from the surface provided with the bidirectional oil drive return portion 123. The tension spring 13 can surround and be installed on the radial outer side of the main sealing lip 122 and press the main sealing lip 122 radially inward, so that the main sealing lip 122 is closely abutted against the inner ring or the shaft.

[0034] According to an embodiment of the present invention, a sealing assembly is further provided. The sealing assembly comprises the sealing device 1 described in any one of the above embodiments and an element rotating relative to the sealing device 1. The lip 122a of the main sealing lip 122 contacts the circumferential surface of the element. The element may be a bearing inner ring, an end cover or a shaft, etc.

[0035] In some optional embodiments, the two sides of the lip 122a in the axial direction A are the grease side and the air side, respectively, and the bidirectional oil drive back portion 123 is located on the air side, so that the bidirectional oil drive back portion 123 can pump the lubricating oil or grease thrown out from the grease side to the air side back to the grease side during the forward and reverse rotation of the element.

[0036] It should be noted that the present invention aims to improve the sealing lip in the sealing device, so the technical solution of the present invention can be applied to various sealing devices, and is not limited to the specific components of the specific sealing device shown in the embodiment. The number, shape and arrangement of the sealing lips are not limited to the limitations in the above description. In addition, the present invention can also be applied to other non-annular sealing devices for dynamic sealing.

[0037] Although possible embodiments are described by way of example in the above description, it should be understood that there are still a large number of variations of embodiments through the combination of all known and other technical features and embodiments that are easily conceivable to the skilled person. It should also be understood that the exemplary embodiment is only an example and that such an embodiment in no way limits the scope of protection, application and configuration of the present invention. The above description is more to provide the skilled person with a technical guide for converting at least one exemplary embodiment, wherein various changes can be made, especially changes in the functions and structures of the components, as long as they do not depart from the scope of protection of the claims.

[0038] Reference numerals list

[0039] 1. Sealing device;

[0040] 11. Rigid annular parts;

[0041] 12. Elastic sealing ring; 121. Main body; 122. Main sealing lip; 122a. Lip opening; 123. Two-way oil drive return portion; 123a. Arc surface; 123b. Flat surface; 124. Secondary sealing lip;

[0042] 13. Tension the spring.

Claims

1. A sealing device, characterized in that: include: A rigid annular component (11) and an elastic sealing ring (12); the elastic sealing ring (12) is arranged radially inside the rigid annular component (11); The elastic sealing ring (12) comprises a main body (121) and a main sealing lip (122), wherein the main body (121) is fixed on the rigid annular member (11), and the main sealing lip (122) is a free end extending from the main body (121) and has a lip (122a) for contact sealing; The main sealing lip (122) is provided with a bidirectional oil drive return portion (123) located radially outside the lip opening (122a), and the bidirectional oil drive return portion (123) includes a pair of arc surfaces (123a) protruding from the surface relatively close to the lip opening (122a), and the pair of arc surfaces (123a) are arranged in an axisymmetric manner and extend obliquely from the radial inner side to the radial outer side respectively toward both sides of the circumferential direction (C).

2. The sealing device according to claim 1, characterized in that: The arc surface (123a) is perpendicular to the surface of the lip (122a), and the angle between the pair of arc surfaces (123a) and the circumferential direction (C) gradually decreases along both sides.

3. The sealing device according to claim 1, characterized in that: The ends of both sides of the pair of arc surfaces (123a) are parallel to the circumferential direction (C).

4. The sealing device according to claim 1, characterized in that: The two-way oil drive-back portion (123) is provided in plurality and is evenly distributed on the main sealing lip (122) along the circumferential direction (C).

5. The sealing device according to claim 1, characterized in that: The bidirectional oil drive-back portion (123) includes a straight surface (123b) perpendicular to the surface of the main sealing lip (122) and parallel to the circumferential direction (C) on a side facing the main body portion (121).

6. The sealing device according to claim 1, characterized in that: The elastic sealing ring (12) is made of rubber material.

7. The sealing device according to claim 1, characterized in that: The main body (121), the main sealing lip (122) and the bidirectional oil drive-back portion (123) are an integrally formed structure.

8. The sealing device according to claim 1, characterized in that: An annular tension spring (13) is provided on the side of the main sealing lip (122) facing away from the surface on which the bidirectional oil drive return portion (123) is provided.

9. A sealing assembly, comprising a sealing device (1) as described in any one of claims 1 to 8 and an element rotating relative to the sealing device (1), wherein the lip (122a) of the main sealing lip (122) contacts the circumferential surface of the element, and the element is a bearing inner ring, an end cover or a shaft.

10. The sealing assembly according to claim 9, characterized in that: The two sides of the lip (122a) in the axial direction (A) are respectively a grease side and an air side, and the bidirectional oil drive return portion (123) is located on the air side.

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