CN114542718A - Seal ring and seal unit - Google Patents

Abstract

The invention relates to a seal ring and a seal unit. The seal ring (1) comprises: an elastic sealing part (11) which forms a sealing lip (111) on one radial side, wherein the sealing lip (111) is used for abutting against a component (4) capable of rotating relative to the sealing ring (1) so as to form dynamic sealing between an air side and a fluid side, and a bidirectional fluid return structure is formed on a sealing inclined surface of the sealing lip (111) facing the air side; and leaf springs (12) which are distributed in the circumferential direction at the elastic seal portion (11) and which apply a pressing force to the seal lip (111) toward the member (4). The sealing unit comprises the sealing ring (1) and a component (4) capable of rotating relative to the sealing ring (1), wherein the sealing ring (1) can abut against the component (4) to form dynamic sealing.

Description

Seal ring and seal unit

Technical Field

The invention relates to a sealing technology. The invention particularly relates to a sealing ring of a large bearing, which is particularly used in the field of wind power. The invention also relates to a sealing unit comprising the sealing ring.

Background

At present, sealing rings made of rubber are often arranged at wind power bearings for wind power plants. The sealing ring is mounted, for example, on a sealing seat of the cover ring and forms an interference fit in the axial direction with the inner ring of the bearing and the cover ring, respectively. The sealing ring is configured with a main lip on the grease side and a dust lip on the air side, wherein both sealing lips form a dynamic contact seal with an end cap fixedly connected at the outer ring of the bearing to prevent external contaminants from entering the bearing and to prevent leakage of the grease inside the bearing.

However, since wind turbine bearings for wind turbines have a large diameter, for example a diameter of more than 1.5m, in particular more than 2m, it is very difficult to produce a sealing ring with a metal skeleton that is adapted to the dimensions of such large bearings. Furthermore, even if a seal ring with a metal skeleton is manufactured, it is difficult to install such a large seal ring in a wind turbine generator. In other words, current sealing rings for wind power bearings are made only of rubber. In this case, the sealing ring is not additionally supported or reinforced and is therefore very flexible and easily deformed during assembly. This can result in a number of gaps between the end cap and the sealing lip of the sealing ring, so that grease can leak out.

Disclosure of Invention

The object of the present invention is therefore to provide a sealing arrangement, in particular for large bearings, which provides good sealing properties.

The above object is achieved in a first aspect of the present invention by a seal ring. A seal ring provided herein includes a resilient seal portion and a leaf spring. The elastic sealing part forms a sealing lip on one radial side, the sealing lip is used for abutting against a component capable of rotating relative to the sealing ring, so that a dynamic seal is formed between the air side and the fluid side, wherein a bidirectional fluid return structure is formed on a sealing inclined surface of the sealing lip, which faces the air side. The leaf springs are distributed in the circumferential direction at the elastic sealing portion and apply a pressing force to the sealing lip towards the above-mentioned member rotatable relative to the sealing ring.

The sealing ring can be used in particular for dynamically sealing an annular gap, in particular an annular gap of large diameter, between components that can rotate relative to one another. Here, the members rotatable relative to each other may be a first member and a second member arranged around each other, wherein the sealing ring is fixable at the first member and is relatively slidably abuttable against the second member. The radially outwardly arranged member of the first and second members may be, for example, a housing part of the end cap or an outer ring of the bearing. The radially inner one of the first and second members may be a shaft-like section of a shaft or of a component, for example a housing part of a cover ring or an inner ring of a bearing.

By means of the sealing ring, it is thus possible to dynamically space apart, in particular axially, a fluid chamber which can contain a fluid, for example grease, and a space which is free of fluid or has only a small amount of fluid leaking. The fluid side is here the side facing the fluid chamber containing the fluid, for example oil, and the air side is the side facing the space with no fluid or fluid with only a small amount of leakage.

Within the scope of the present description, the central axes of the sealing ring, the first component and the second component coincide. Unless otherwise indicated, the terms "axial," "radial," and "circumferential" are based on the central axis of the seal ring, where "axial" is a direction parallel to or coincident with the central axis of the seal ring, "radial" is a direction perpendicular to the central axis of the seal ring, and "circumferential" is a direction around the central axis of the seal ring.

Preferably, the elastic sealing portion is made of rubber. The elastic seal comprises a fastening support section, which is formed on one radial side of the sealing ring, for fastening to the first component, and a sealing lip, which is formed on the other radial side of the sealing ring, for abutting against the second component.

Advantageously, the sealing lip is formed radially outside the elastic sealing portion. The sealing ring is fixed to the first component on the radial inner side thereof and forms a dynamic seal with respect to the second component on the radial outer side.

Alternatively, the sealing lip is configured radially inside the elastic sealing portion. The sealing ring is fixed to the first component on the radial outer side thereof and forms a dynamic seal with respect to the second component on the radial inner side.

In this case, advantageously, the contact point of the sealing lip, in particular the sealing lip serving as the main lip, with the second component can be formed on the circumferential surface of the second component. At this time, the seal lip abuts the second member substantially in the radial direction.

Alternatively, a contact point of the sealing lip, in particular the sealing lip serving as the main lip, with the second component may be formed on an axial end face of the second component. At this point, the sealing lip at least partially axially abuts the second component.

Advantageously, the sealing lip, in particular the main lip, has a first sealing bevel facing the air side and a second sealing bevel facing the fluid side, wherein the angle of the first sealing bevel relative to the second component is smaller than the angle of the second sealing bevel relative to the second component. In other words, the first sealing ramp is relatively gentle and the second sealing ramp is relatively steep. It is thereby possible to cause fluid, in particular grease, which has leaked from the fluid side to the air side during dynamic processes to be pumped back to the fluid side, according to the basic mechanism of the pumping effect.

A bidirectional fluid return structure is to be understood here to mean, in particular, a convex ridge-like structure provided at the first sealing bevel for enhancing the pumping effect, in order to pump fluid on the air side back into the fluid side upon a bidirectional relative rotation of the first and second component, which accommodates, for example, a forward and a reverse rotation of the bearing. Within the scope of this document, the shape of each of the fins that make up the bi-directional fluid return structure is not limited. In this case, it is particularly advantageous if the individual ribs are linear, polygonal and/or curved. In embodiments where the fluid is oil or grease, the fluid return structure forms a return line.

Preferably, the leaf spring is made of a resilient metal sheet. Advantageously, the leaf spring is fixed by a vulcanization process at an elastic sealing portion, in particular made of rubber. Preferably, the leaf spring is designed as a bent leaf, wherein one end of the leaf spring rests against the fixed bearing section of the elastic sealing portion and the other end of the leaf spring rests against the rear side of the sealing lip, whereby the leaf spring exerts a pressing force on the sealing lip towards the second component, so that the sealing lip, in particular the first sealing bevel, is in close contact with the second component. Particularly preferably, the curved profile of the leaf spring matches the profile of the resilient sealing portion in the axial and/or radial direction, so that the leaf spring and the resilient sealing portion have a large contact area, which may enhance the firmness of the connection between the leaf spring and the resilient sealing portion. Advantageously, the leaf springs are distributed uniformly in the circumferential direction at least in groups at the elastic sealing portion, whereby the sealing lip, in particular the main lip, can be provided with a uniform contact pressure after installation.

The sealing ring provided herein is easy to manufacture and install at annular gaps with a larger diameter, which is particularly suitable for sealing large bearings, for example in the wind power field. In particular, the play of the sealing ring, in particular the sealing lip serving as the main lip, with respect to the second component can be eliminated by means of the leaf spring, the sealing ring having better sealing properties and being able to compensate for greater eccentricities. Here, the pumping effect when the first member and the second member are rotated relative to each other in both directions can be correspondingly enhanced on the one hand by the bidirectional fluid return structure, so that the fluid having leaked to the air side can be pumped to the return fluid side; on the other hand, the first sealing inclined surface of the sealing lip can be kept with fluid all the time, namely, a uniform lubricating film is formed, so that the abrasion of the sealing ring in the process of rotating relative to the second component in any rotating direction is reduced, and the maintenance cost is reduced. Accordingly, the seal ring provided herein can provide good sealing performance and at a lower cost.

In a preferred embodiment, the sealing ring further comprises a skeleton made of a fabric, so that a good support can be provided for the elastic sealing portion, which is in particular made of rubber. Furthermore, the sealing ring with the carcass made of a fiber fabric is easy to manufacture and is relatively inexpensive. In addition, the seal ring provided by the present embodiment is easier to mount to the first member for a large bearing than a seal ring with a metal skeleton, particularly in a case where the seal ring is fixed to the first member by interference fit. In this case, the skeleton, which is advantageously made of a fiber fabric, is arranged at the fastening support section for fastening to the first component.

In a preferred embodiment, the bidirectional fluid return structure comprises a circumferentially continuous rib at the air side facing sealing ramp, i.e. the first sealing ramp. The seal ring thereby directly blocks fluid flow from the fluid side to the air side, thereby reducing fluid leakage when rotating in either direction relative to the second member.

Particularly preferably, the bidirectional fluid return structure is configured as a grid-like ridge. In this case, a plurality of circumferentially continuous webs surrounded or closed by ribs is formed by the bidirectional fluid return structure. When the seal ring rotates relative to the second member, the fluid leaking from the seal lip can be pumped back to the fluid side in a large amount by the respective meshes from the fluid side to the air side, so that it is difficult for the fluid to continue flowing toward the air side, and thus the leakage of the fluid can be effectively blocked. Further, when the large bearing is in a stationary state for a long time, even if there is leakage of fluid, the leaked fluid can be largely held in each mesh from the fluid side to the air side, thereby reducing the leakage or even preventing the leakage. In addition, the first sealing inclined surface of the sealing lip can be kept with fluid all the time under the condition of ensuring the sealing performance by virtue of the grid-shaped convex edges, for example, a lubricating film is formed all the time, so that the abrasion of the sealing ring in the process of rotating relative to the second component is reduced, and the maintenance cost is reduced.

In an alternative embodiment, the bidirectional fluid return structure may also be configured as two-by-two splayed ridges arranged along the circumferential direction.

In an advantageous embodiment, the elastic sealing part is configured with a pumping groove towards the fluid side, so that the fluid can be pushed towards the fluid side to reduce leakage of the fluid. Preferably, the pumping groove is configured at the sealing lip.

In an advantageous embodiment, the leaf spring is configured with a cutout. Here, the hollowed-out portion may be a circular hole, a rectangular hole, or a through hole of any other shape. The cutout can be formed at any section of the leaf spring, in particular in the form of a bent leaf. During the production of the sealing ring by means of a vulcanization process, some of the semi-solid rubber that is to constitute the elastic sealing portion may pass through the hollowed-out portion of the leaf spring and form a clamping structure after final molding to firmly fix the leaf spring at the elastic sealing portion, thereby preventing the leaf spring from falling off.

In a preferred embodiment, the elastic sealing part is also designed as an additional sealing lip. Within the scope of this document, the number of sealing lips of the sealing ring is not limited. In addition to the sealing lip serving as the main lip, the sealing ring provided here can also have at least one further sealing lip. The additional sealing lip can be arranged here on the air side or on the fluid side relative to the main lip. The further sealing lip may establish a contactless seal and/or a contact seal with the second member.

The above-mentioned technical problem is solved in a second aspect of the present invention by a sealing unit. The sealing unit provided herein comprises a sealing ring according to the above described embodiments and a member rotatable relative to the sealing ring, i.e. a second member, wherein the sealing ring is able to abut against the member, thereby forming a dynamic seal. Here, the second member, which is a member rotatable with respect to the seal ring, may be formed of a member such as a bearing outer ring, a bearing inner ring, an end cap, or a cover ring, depending on the specific arrangement of the seal ring.

In a preferred embodiment, the component rotatable relative to the sealing ring, i.e. the second component, is designed with a collar portion extending in the radial direction towards the sealing ring side, wherein the collar portion is arranged axially on the fluid side of the sealing ring. The annular retainer ring part can block fluid and reduce leakage.

Drawings

Preferred embodiments of the present invention are schematically illustrated in the following with reference to the accompanying drawings. The attached drawings are as follows:

figure 1 is a schematic cross-sectional view of a sealing unit according to a preferred embodiment,

figure 2 is a schematic cross-sectional view of a sealing ring in the sealing unit according to figure 1,

figure 3 is a part of a perspective cross-sectional view of the sealing ring according to figure 2,

figure 4 is a part of a top view of the sealing ring according to figure 2,

fig. 5 is a perspective view of a leaf spring in the sealing ring according to fig. 2, an

Fig. 6 is a perspective view of a part of the sealing ring according to fig. 2.

Detailed Description

Fig. 1 shows a schematic cross-sectional view of a sealing unit according to a preferred embodiment. Here, the sealing unit is used for sealing large bearings in wind turbines. The bearing comprises an outer ring 2 and an inner ring 3 and can perform bidirectional relative rotation according to working conditions. The sealing ring 1 of the sealing unit is fixed on its radial inner side on the sealing seat of the cover ring 5 by interference fit and forms an interference fit with the inner ring 3 of the bearing and the cover ring 5 in the axial direction, respectively. The sealing ring 1 forms a dynamic contact seal on the radially outer side with an end cap 4 which is fixedly connected to the outer ring 2, in order to prevent dirt on the air side from entering the bearing and to prevent leakage of grease on the fluid side, i.e. in this case in the bearing.

Fig. 2 shows a schematic cross-sectional view of the sealing ring 1 in the sealing unit according to fig. 1. The seal ring 1 includes an elastic seal portion 11, a leaf spring 12, and a skeleton 13.

The elastic seal portion 11 is made of rubber. As shown in fig. 2, the elastic seal 11 is formed radially on the inside with a fastening support section for fastening to the cover ring 5. The elastic seal 11 is formed radially on the outside with two sealing lips, namely a main lip 111 arranged on the fluid side and a dust lip 112 arranged on the air side. The main lip 111 abuts substantially radially at the inner peripheral surface of the end cover 4. The main lip 111 has a first sealing slope facing the air side and a second sealing slope facing the fluid side, wherein the first sealing slope has a smaller angle with respect to the inner circumferential surface of the end cap 4 than the second sealing slope has with respect to the inner circumferential surface of the end cap 4.

Fig. 3 shows a detail of the sealing ring 1 according to fig. 2 in a perspective sectional view. Fig. 4 shows a detail of a top view of the sealing ring 1 according to fig. 2. As shown in fig. 2 to 4, a bidirectional fluid return structure 113 is configured at the first sealing slope of the main lip 111. The bidirectional fluid return structure 113 is configured in the present embodiment as ribs arranged in a grid pattern that is continuous in the circumferential direction. Here, a large number of cells surrounded by fins are formed by the bi-directional fluid return structure 113. When the sealing ring 1 is rotated in either direction relative to the end cap 4, for example in the direction shown in fig. 4 by means of arrow 6, grease leaking from the main lip 111 can be pumped back to the fluid side in large amounts by the individual meshes from the fluid side to the air side, as shown by the solid arrows in fig. 4. This makes it difficult for the grease to continue flowing toward the air side, and the seal ring 1 can effectively prevent leakage of the grease. Further, when the large bearing is in a static state for a long time, the base oil and the thickener of the grease may be layered, and at this time, the base oil is easily leaked, and the leaked base oil can be largely stored in each mesh forming the bidirectional fluid return structure 113, thereby reducing the leakage. In addition, the first sealing inclined surface of the main lip 111 can always have a lubricating film by virtue of the latticed convex ribs under the condition of ensuring the sealing performance, so that the abrasion of the sealing ring 1 in the rotating process relative to the end cover 4 is reduced, the service life of the sealing ring 1 can be prolonged, and the maintenance cost is reduced.

As shown in particular in fig. 2, 3 and 6, the elastic sealing portion 11 is configured with a pumping groove 114 facing the fluid side. In this embodiment, the pumping grooves 114 are circumferentially distributed on the fluid side of the main lip 111, so that the grease can be pushed toward the fluid side to reduce leakage of the grease.

Fig. 5 shows a perspective view of the leaf spring 12 in the seal ring 1 of the present embodiment. Fig. 6 shows a perspective view of a part of the seal ring 1 of the present embodiment. As shown in fig. 2, 5 and 6, the leaf spring 12 is composed of a bent elastic metal sheet. The leaf springs 12 are evenly distributed on the fluid side of the elastic seal portion 11 in the circumferential direction. In the present embodiment, the curved profile of the leaf spring 12 matches the fluid-side profile of the resilient sealing portion 11 in the axial as well as in the radial direction. One end of the leaf spring 12 is supported at the fixed support section of the elastic sealing portion 11, and the other end of the leaf spring 12 is supported at the back side of the main lip 111, so that a pressing force, which is radial in this embodiment, toward the end cover 4 is applied to the main lip 111, so that the main lip 111 is brought into close contact with the end cover 4, improving sealing performance.

The leaf spring 12 is fixed at the elastic sealing part 11 by a vulcanization process. The leaf spring 12 is configured with hollowed-out portions 121, 122, 123. During the production of the sealing ring 1 by means of a vulcanization process, some of the semi-solid rubber that is to constitute the elastic sealing portion 11 can pass through the cutouts 121, 122, 123 of the leaf spring 12 and, after the final shaping, form a clamping structure in the form of projections 115, 116 in order to firmly fix the leaf spring 12 at the elastic sealing portion 11, thereby preventing the leaf spring 12 from falling out. Here, the hollow 121 of the projection 115 corresponding to the fixed support section of the elastic sealing part 11 is configured as a rectangular hole, and the hollow 123 of the projection 116 corresponding to the back side of the main lip 111 is configured as a rectangular hole. Furthermore, the cutout 122 in the radial middle region of the leaf spring 12 is configured as a circular hole.

As shown in fig. 2 and 3, the skeleton 13 of the seal ring 1 is made of a fiber fabric, and is disposed radially inside the elastic seal portion 11, so that it is possible to provide good support to the elastic seal portion 11. The sealing ring with the carcass 13 made of a fabric is easy and inexpensive to manufacture. In addition, the framework 13 made of a fiber fabric facilitates a simplified installation and fixing of the sealing ring 1 on the cover ring 5 by means of an interference fit, in particular in comparison to the solution of sealing rings with metal frameworks.

The sealing ring 1 provided herein is easy to manufacture and install at annular gaps with a larger diameter, particularly for large bearings such as those in the field of wind power in this embodiment. In particular, an eccentric arrangement of the sealing ring 1 can advantageously be avoided by means of the leaf spring 12, the clearance of the main lip 111 of the sealing ring 1 with respect to the end cap 4 being effectively eliminated, and the sealing ring 1 having better sealing properties. In this case, in particular by means of the grid-like bidirectional fluid return structure 13, the pumping effect can be correspondingly increased on the one hand when the cover ring 5 and the end cover 4 or the inner ring 3 and the outer ring 2 of the bearing rotate relative to one another in both directions, so that grease which has leaked to the air side can be pumped back to the fluid side; on the other hand, the first sealing inclined surface of the main lip 111 can always keep a lubricating film, so that the abrasion of the sealing ring 1 in relative rotation with respect to the end cover 4 is reduced, and the maintenance cost is reduced. Accordingly, the seal ring 1 provided herein can provide good sealing performance and have a lower cost and longer service life.

Furthermore, in order to further improve the sealing performance of the sealing unit, as shown in fig. 1, a retainer ring portion 41 extending toward the side of the seal ring 1 in the radial direction may be further configured at a member rotatable with respect to the seal ring 1, in the present embodiment, the end cap 4. Here, the retainer ring portion 41 is arranged on the fluid side of the seal ring 1 in the axial direction. Leakage of grease can be reduced by the annular collar portion 41.

Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.

List of reference numerals

1 sealing element

11 elastic seal part

111 major lip

112 dust lip

113 bidirectional fluid return structure

114 pumping trough

115 projection

116 projection

12 leaf spring

121 hollow part

122 hollow out part

123 hollowed-out part

13 skeleton

2 outer ring

3 inner ring

4 second member, end cap

41 retainer ring

5 first component, cover ring

6 arrow head

Claims (10)

1. Sealing ring (1) comprising:

an elastic sealing part (11) which forms a sealing lip (111) on one radial side, wherein the sealing lip (111) is used for abutting against a component (4) which can rotate relative to the sealing ring (1) so as to form dynamic sealing between an air side and a fluid side, and a bidirectional fluid return structure is formed on a sealing inclined surface of the sealing lip (111) facing to the air side; and

leaf springs (12) which are distributed in the circumferential direction at the elastic sealing portion (11) and which apply a pressing force to the sealing lip (111) towards the component (4).

2. The sealing ring (1) according to claim 1, wherein the sealing lip (111) is configured radially outside or radially inside the elastic sealing portion (11).

3. The sealing ring (1) according to claim 1, wherein the sealing ring (1) further comprises a skeleton (13) consisting of a fiber fabric.

4. The sealing ring (1) according to claim 1, wherein the bidirectional fluid return structure (113) comprises a circumferentially continuous ridge at the sealing bevel.

5. Sealing ring (1) according to claim 4, wherein the bidirectional fluid return structure (113) is configured as a grid-like ridge.

6. Sealing ring (1) according to claim 1, wherein the resilient sealing portion (11) is configured with a pumping groove (114) towards the fluid side.

7. The seal ring (1) according to claim 1, wherein the leaf spring (12) is configured with a hollowed-out portion (121, 122, 123).

8. The sealing ring (1) according to claim 1, wherein the elastic sealing portion (11) is further configured with an additional sealing lip (112).

9. A sealing unit, comprising:

-a sealing ring (1) according to any one of claims 1 to 8; and

-a member (4) rotatable relative to the sealing ring (1),

wherein the sealing ring (1) can abut against the component (4) so as to form a dynamic seal.

10. The sealing unit according to claim 9, wherein the member (4) is configured with a collar portion (41) extending radially towards one side of the sealing ring (1), wherein the collar portion (41) is arranged axially on the fluid side of the sealing ring (1).

Images