CN113565961A

CN113565961A - Sealing device

Info

Publication number: CN113565961A
Application number: CN202110854575.XA
Authority: CN
Inventors: 刘鑫; 吴丽娟; 王为华; 杨树升; 贾宪林; 司德纯
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2021-07-28
Filing date: 2021-07-28
Publication date: 2021-10-29

Abstract

The present invention relates to a sealing device. The sealing device is used for dynamically sealing between a first rotating component and a second rotating component which can rotate relatively, and comprises a floating ring and an elastic sealing ring which are arranged around a rotating axis. Wherein, this sealing device still includes the skeleton of arranging around axis of rotation, elastic sealing body and sealed lid, the skeleton is used for fixing on radial outside's first rotating member, the elastic sealing body is fixed on the skeleton and includes the at least one seal lip that extends towards radial inboard and seal the second rotating member, sealed lid is fixed on the elastic sealing body, make a part of elastic sealing body support between skeleton and sealed lid in the axial, the floating ring along axial butt sealed lid in the opposite side of skeleton, and can rotate for sealed lid, the floating ring is radial outside and in the axial direction butt elastic sealing ring of sealed lid dorsad. The sealing device of the present invention has improved performance.

Description

Sealing device

Technical Field

The invention relates to the technical field of sealing. In particular, the present invention relates to a sealing device for dynamically sealing a rotating part.

Background

Currently, floating seal devices are mainly used in various construction and engineering machines, such as excavators, bulldozers, tunnel boring machines, mining machines, agricultural machines, heavy trucks, etc. These machines are subject to very severe operating conditions that can cause severe wear.

The floating sealing device is composed of two metal floating rings which are mutually abutted in an independent cavity along the axial direction, and two elastic sealing rings are respectively distributed in the respective cavities. Such a floating seal device is disclosed in patent documents CN101479509A and the like, for example. The elasticity of the elastic sealing ring generates uniform axial load to the floating ring. The inner side surface and the outer side surface of the elastic sealing ring are statically sealed, the floating rings are prevented from rotating along with the shaft, and torque is prevented from being transmitted between the two floating rings through the sliding fit of the end surfaces. Only one of the two floating rings is rotating while the other is stationary, forming a leak-proof seal. This can effectively prevent intrusion of external contaminants and prevent leakage of internal grease.

The floating seal assembly must be installed to ensure that the elastomeric seal ring does not distort or otherwise leak or even fail, causing the elastomeric seal ring to fail prematurely. After a period of operation of the two floating rings, the end faces for abutment will wear out so that the fit is no longer tight, thereby causing leakage. In addition, the friction torque between the two metal floating rings is also increased, so that the static floating ring is forced to rotate, the elastic sealing ring installed on the static floating ring is distorted and even damaged, and leakage is caused between the static floating ring and the elastic sealing ring.

Disclosure of Invention

The invention is therefore based on the object of providing a sealing device with improved properties.

The above-mentioned technical problem is solved by a sealing device according to the present invention. The sealing device is used for dynamically sealing between a first rotating component and a second rotating component which can rotate relatively, and comprises a floating ring and an elastic sealing ring which are arranged around a rotating axis. Wherein, this sealing device still includes the skeleton of arranging around axis of rotation, elastic sealing body and sealed lid, the skeleton is used for fixing on radial outside's first rotating member, the elastic sealing body is fixed on the skeleton and includes the at least one seal lip that extends towards radial inboard and seal the second rotating member, sealed lid is fixed on the elastic sealing body, make a part of elastic sealing body support between skeleton and sealed lid in the axial, the floating ring along axial butt sealed lid in the opposite side of skeleton, and can rotate for sealed lid, the floating ring is radial outside and in the axial direction butt elastic sealing ring of sealed lid dorsad. The sealing device adopts the design of combining the fixed sealing structure with the floating sealing structure, and the fixed sealing structure consisting of the framework, the elastic sealing body and the sealing cover can provide stable axial support for the floating sealing structure, thereby ensuring the sealing effect of the floating sealing structure.

According to a preferred embodiment of the invention, the resilient sealing body may comprise a support portion axially supported between the skeleton and the sealing cover, which support portion may have an axial thickness larger than the thickness of the remaining section of the resilient sealing body. Elastic supporting part supports between sealed lid and skeleton, and sealed lid is along axial butt floating ring, and when the skew takes place or wearing and tearing as floating seal ring, the supporting part can provide the compensation for floating seal structure through elastic deformation.

According to a further preferred embodiment of the invention, the sealing cover may comprise a radial section which may axially abut an end face of the support facing the floating ring, and an axial section which may radially inwardly abut a radially outer side face of the support. The axial section serves to provide axial support for the floating ring, while the radial section ensures radial positioning of the sealing cap relative to the elastic sealing body and prevents the sealing cap from falling off the elastic sealing body.

According to a further preferred embodiment of the invention, the skeleton may comprise a fixing portion for radially abutting the first rotational part, the fixing portion may extend axially radially outside the axial section and be radially spaced apart from the axial section. The bobbin may be fixed to the first rotating member by interference fit of the fixing portion with the first rotating member. Preferably, the elastic sealing body may cover a radially outer side surface of the fixing portion such that the fixing portion indirectly abuts the first rotating member via the elastic sealing body.

According to another preferred embodiment of the present invention, the seal cover may include a seal cover coating layer, and the floating ring and the seal cover coating layer may be respectively made of low friction materials, and the seal cover may abut against the floating ring in an axial direction via the seal cover coating layer, thereby reducing wear of the seal cover and the floating ring. Preferably, such a low friction material may be, for example, polytetrafluoroethylene.

According to another preferred embodiment of the invention, the sealing device may further comprise a spring, the at least one sealing lip may comprise a primary sealing lip, the spring may be mounted radially outside the sealing lip and press the primary sealing lip inwards, thereby ensuring that the primary sealing lip is in close abutment and seals the radially inside second rotational part. Preferably, the at least one sealing lip may further comprise a secondary sealing lip, the secondary sealing lip being axially closer to the floating ring than the primary sealing lip.

According to another preferred embodiment of the present invention, the primary seal lip may have a seal lip coating layer made of a low friction material, the primary seal lip being able to contact the second rotating member via the seal lip coating layer, thereby reducing wear on the primary seal lip.

According to another preferred embodiment of the invention, the sealing device may further comprise an anti-rotation pin, a part of which may be inserted into the floating ring and another part of which may be used for insertion into the second rotating member. The rotation of the floating ring relative to the second rotating member can be reliably prevented by the rotation preventing pin.

Drawings

The invention is further described below with reference to the accompanying drawings. Identical reference numbers in the figures denote functionally identical elements. Wherein:

FIG. 1 shows a cross-sectional view of a seal arrangement according to an embodiment of the invention when installed in a bearing;

FIG. 2 shows a perspective cross-sectional view of the sealing device shown in FIG. 1;

FIG. 3 shows a cross-sectional view of a sealing device according to another embodiment of the invention when installed in a bearing; and

fig. 4 shows a perspective cross-sectional view of the sealing device shown in fig. 3.

Detailed Description

Hereinafter, a specific embodiment of the sealing device according to the present invention will be described with reference to the accompanying drawings. The following detailed description and drawings are included to illustrate the principles of the invention, which is not to be limited to the preferred embodiments described, but is to be defined by the appended claims.

According to an embodiment of the present invention, a sealing device for dynamic sealing is provided. Such sealing devices are used for sealing between two relatively rotatable parts, for example between an outer ring and an inner ring of a bearing.

Fig. 1 and 2 show an exemplary embodiment of a sealing device according to the invention. In fig. 1, the sealing device is mounted in a bearing. In this embodiment, one of the two rotating components sealed by the sealing device is the outer ring 2 of the bearing and a component fixedly connected with the outer ring 2, such as the hub 1 or the like supported radially outward of the outer ring 2 in an interference fit manner, while the other is the inner ring 3 and a component fixedly connected with the inner ring 3, such as a shaft mounted radially inward of the inner ring 3 in an interference fit manner and the end cover 5 or the like fixed beyond an axial end of the inner ring 3. A plurality of rolling elements 4 of the bearing are arranged between the outer ring 2 and the inner ring 3 such that relative rotation between the outer ring 2 and the inner ring 3 is possible about the rotational axis of the bearing.

The sealing device includes a fixed sealing portion and a floating sealing portion. Fig. 2 shows a perspective cross-sectional view of the stationary seal part. As shown in fig. 2, the stationary seal portion includes a frame 6, an elastic seal body 7, a seal cover 8, and a spring 9, which are all of annular structures arranged around the rotational axis of the seal device. As shown in fig. 1, the outer portion of the frame 6 is fixed to the radially outer side of the outer ring 2 by, for example, interference fit, and therefore, the axial length of the outer ring 2 is extended as compared with the prior art. The remaining portion of the bobbin 6 extends radially inward beyond the end of the outer ring 2. The carcass 6 may be made of a rigid material, such as metal, for example, to provide support for the elastomeric seal 7.

The elastic sealing body 7 is fixed to the frame 6, for example, by a vulcanization process. The elastic sealing body 7 is made of an elastic material such as rubber. The radially inner edge of the elastomeric sealing body 7 continues inwardly from the carcass 6 to form at least one annular sealing lip. In the present embodiment, the elastic sealing body 7 has a primary sealing lip 16. The primary seal lip 16 is provided with an annular spring 9 on the radially outer side, and the spring 9 presses the primary seal lip 16 radially inwardly so that the primary seal lip 16 is tightly abutted on the outer side surface of the inner race 3 in the radial direction. The elastic sealing body 7 may also have an annular secondary sealing lip 17, the secondary sealing lip 17 extending obliquely on the side of the primary sealing lip 16 facing away from the rolling bodies 4. The free end of the secondary sealing lip 17 may or may not contact the inner ring 3.

The seal cover 8 is an annular member that is mounted on the side of the frame 6 away from the outer ring 2 in the axial direction. A part of the elastic sealing body 7 is supported between the bobbin 6 and the seal cover 8 in the axial direction, and this part is referred to as a support portion 13. The support portion 13 is thus located on the side of the skeleton 6 away from the outer ring 2 in the axial direction. The support 13 preferably has an axial thickness greater than the thickness of the remaining section of the elastic sealing body 7. In particular, the axial thickness of the support 13 can be much greater than the thickness of the sealing lip. Preferably, the support portion 13 may cover a region from a middle position of the bobbin 6 to a radially outer side in the radial direction, and in particular may pass over an axial section of the bobbin 6 for interference fit with the inner outer ring 2 to the radially outer side and cover the axial section from the radially outer side.

The sealing cover 8 may be fixed with the elastic sealing body 7 by, for example, vulcanization or other processes. The sealing cover 8 may be made of a rigid material such as metal, for example. The sealing cover 8 may have a radial section extending in the radial direction, which axially abuts an end face of the support 13 facing away from the outer ring 2. Furthermore, the seal cover 8 may also have an axial section extending axially from the outer edge of the radial section towards the outer ring 2, which axial section is located radially outside the support 13 and radially inwards abuts the radially outer side face of the support 13. The axial section of the sealing cover 8 makes it possible to position the sealing cover 8 radially with respect to the elastic sealing body 7, reducing the risk of the sealing cover 8 falling off.

The floating seal portion includes a floating ring 10 and an elastic seal ring 11. The floating ring 10 and the elastic sealing ring 11 are both annular structures arranged around the axis of rotation. When the sealing device is installed in the bearing, the floating ring 10 abuts axially against the side of the sealing cover 8 facing away from the skeleton 6, in particular against a radial section of the sealing cover 8. The end surface of the floating ring 10 for abutting against the seal cover 8 is formed as a flat and smooth surface extending perpendicular to the rotation axis, thereby being in flat contact with the seal cover 8.

The elastic seal ring 11 may be made of an elastic material such as rubber, for example. The floating ring 10 abuts the elastic sealing ring 11 radially outwards and in an axial direction facing away from the sealing cover 8, so that the elastic sealing ring 11 is pressed obliquely onto the end cap 5. In order to achieve such an oblique pressing direction, the floating ring 10 can be formed with an obliquely oriented annular recess on the side facing away from the sealing cover 8.

When the seal is installed in a bearing, the components of the stationary seal section remain stationary with respect to the outer ring 2 and the hub 1, and the components of the floating seal section remain stationary with respect to the inner ring 3 and the end cap 5. Therefore, when there is relative rotation between the outer ring 2 and the inner ring 3, there is also relative rotation between the fixed seal portion and the floating seal portion. Specifically, the seal cover 8 and the floating ring 10 are relatively rotatable, and therefore sliding friction occurs on the axial end surfaces abutting each other. In order to reduce such a frictional force, a seal cover coating layer 15 may be formed on the seal cover 8, and both the seal cover coating layer 15 and the floating ring 10 may be made of a low-friction material, for example, Polytetrafluoroethylene (PTFE). Such materials can reduce friction and have sufficient hardness and strength. Similarly, a seal lip coating layer 18 made of a low friction material such as PTFE may also be formed on the primary seal lip 16, and the primary seal lip 16 may contact the inner ring 3 via the seal lip coating layer 18.

Fig. 3 and 4 show another embodiment of a sealing device according to the invention. This embodiment changes the structure of the hub 1 and the end cap 5 to which the bearing is mounted. The difference between this embodiment and the embodiment shown in fig. 1 and 2 is mainly that the frame 6 further comprises a fixing portion 14. The securing portion 14 extends axially radially outside the axial section of the sealing cover 8 and is radially spaced apart from the axial section of the sealing cover 8. The fixing portion 14 radially abuts the hub 1 so as to be fixed radially inside the hub 1, for example, with an interference fit. In this case, the frame 6 does not need to be directly fixed to the outer ring 2, and therefore the axial length of the outer ring 2 can be shortened. Preferably, the elastic sealing body 7 may cover a radially outer side surface of the fixing portion 14 so that the fixing portion 14 abuts against the hub 1 via the material of the elastic sealing body 7, whereby the sealing effect may be enhanced. An annular groove may be additionally formed in the material of this portion of the elastic sealing body 7. Furthermore, an anti-rotation pin 12 may be provided, a portion of the anti-rotation pin 12 being inserted into the floating ring 10 and another portion being inserted into the end cap 5. The anti-rotation pin 12 ensures that the floating ring 10 remains stationary relative to the second rotating part. Furthermore, the mating surfaces of the end cap 5 and the hub 1 may be modified to form a mating stepped cross-sectional profile as shown in fig. 3 to further prevent external contaminants from entering the interior of the seal.

The seal assembly according to the present invention combines a fixed seal portion with a floating seal portion to provide axial support for the seal cover by a portion of the elastomeric seal body secured to the armature. The support portion of the elastic sealing body is compressed in the axial direction, and therefore, an opposite elastic force is applied to the sealing cover, so that the sealing cover and the floating ring are tightly abutted together. Because the sealing cover is fixed on the elastic sealing body, the elastic sealing body is fixed on the framework, and the framework is fixed on the first rotating part, the mounting position of the sealing cover is not easy to deviate. When the elastic sealing ring or the floating ring of the floating sealing part is worn, the supporting part of the elastic sealing body can provide compensation through elastic deformation, so that the sealing effect of the floating sealing part is ensured. In addition, the sealing device is easy to produce and install, and contributes to reducing the processing cost.

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 hub

2 outer ring

3 inner ring

4 rolling element

5 end cap

6 skeleton

7 elastic sealing body

8 sealing cover

9 spring

10 floating ring

11 elastic sealing ring

12 anti-rotation pin

13 support part

14 fixed part

15 seal cover coating

16 primary sealing lip

17 auxiliary sealing lip

18 seal lip coating

Claims

1. A sealing device for dynamic sealing between a first and a second relatively rotatable component, comprising a floating ring (10) and an elastic sealing ring (11) arranged around an axis of rotation,

it is characterized in that the preparation method is characterized in that,

the sealing device also comprises a framework (6) arranged around the rotation axis, an elastic sealing body (7) and a sealing cover (8), said skeleton (6) being intended to be fixed to said first rotating part radially on the outside, said elastic sealing body (7) being fixed to said skeleton (6) and comprising at least one sealing lip extending towards the radially inside for sealing said second rotating part, the sealing cover (8) is fixed to the elastic sealing body (7) such that a part of the elastic sealing body is supported in the axial direction between the frame (6) and the sealing cover (8), the floating ring (10) is abutted against the sealing cover (8) along the axial direction at the side opposite to the framework (6), and is rotatable relative to the sealing cover (8), the floating ring (10) abutting the elastic sealing ring (11) radially outwards and in an axial direction facing away from the sealing cover (8).

2. A sealing arrangement according to claim 1, characterised in that the resilient sealing body (7) comprises a support portion (13) axially supported between the skeleton (6) and the sealing cover (8), the support portion (13) having an axial thickness greater than the thickness of the remaining section of the resilient sealing body (7).

3. A sealing arrangement according to claim 2, characterized in that the sealing cover (8) comprises a radial section which axially abuts an end face of the support portion (13) facing towards the floating ring (10), and an axial section which radially inwardly abuts a radially outer side face of the support portion (13).

4. A sealing arrangement according to claim 3, characterized in that the frame (6) comprises a fixing portion (14) for radially abutting the first rotational member, the fixing portion extending axially radially outside the axial section and being radially spaced from the axial section.

5. A sealing arrangement according to claim 4, characterized in that the elastic sealing body (7) covers a radially outer side of the fixing portion (14).

6. The sealing arrangement according to claim 1, characterized in that the seal cap (8) comprises a seal cap coating (15), the floating ring (10) and the seal cap coating (15) each being made of a low friction material, the seal cap (8) axially abutting the floating ring (10) via the seal cap coating (15).

7. A sealing arrangement according to claim 6, characterized in that the sealing arrangement further comprises a spring (9), the at least one sealing lip comprising a main sealing lip (16), the spring (9) being mounted radially outside the main sealing lip (16) and pressing the main sealing lip (16) inwards.

8. The sealing arrangement according to claim 7, characterized in that the at least one sealing lip further comprises a secondary sealing lip (17), the secondary sealing lip (17) being axially closer to the floating ring (10) than the primary sealing lip (16).

9. A sealing arrangement according to claim 7, characterized in that the primary sealing lip (16) has a sealing lip coating (18) made of a low friction material, via which sealing lip coating (18) the primary sealing lip (16) can contact the second rotating part.

10. A sealing arrangement according to any one of claims 1 to 9, characterized in that the sealing arrangement further comprises an anti-rotation pin (12), a part of the anti-rotation pin (12) being inserted into the floating ring (10) and another part being intended to be inserted into the second rotating part.