CN113606341A

CN113606341A - Sealing device

Info

Publication number: CN113606341A
Application number: CN202110854606.1A
Authority: CN
Inventors: 刘鑫; 吴丽娟; 王星星; 刘志恒
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: 2021-11-05

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 an annular framework, an elastic sealing body and a dustproof cover which are arranged around a rotating axis, wherein the framework is used for being fixed on the first rotating component on the radial outer side, the dustproof cover is used for being fixed on the second rotating component on the radial inner side, the elastic sealing body is fixed on the framework, and a sealing path which is communicated with the sealing side and the outer side is formed between the elastic sealing body and the dustproof cover. The elastic sealing body has a plurality of sealing lips extending toward the dust cover, one of the plurality of sealing lips closest to the sealing side on the sealing path is a radial sealing lip extending in the radial direction, and the radial sealing lip contacts the dust cover in parallel. The sealing device of the present invention has improved sealing 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, metal sealing covers are commonly applied in axle boxes of rail vehicles to prevent external contaminants from intruding into the bearings and grease leakage inside the bearings. Such a sealing cap is disclosed in patent documents CN 108105255 a and the like.

In the prior art, the seal cap is typically press-fit to the inside of the bearing outer race and held stationary relative to the outer race by an interference fit. To avoid generating additional friction torque, the sealing cover and the bearing inner ring should be in clearance fit. Due to such clearance fit, the lubricating grease is liable to leak, and when cleaning a vehicle with a high-pressure water gun, splashed droplets are liable to intrude into the interior of the bearing through the clearance, and external contaminants are also liable to intrude into the interior of the bearing through the clearance. If a sealing device having a contact seal lip is used, the frictional force generated on the contact surface of the seal lip may be excessive.

Disclosure of Invention

The present invention is therefore based on the object of providing an improved sealing arrangement.

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 an annular framework, an elastic sealing body and a dustproof cover which are arranged around a rotating axis, wherein the framework is used for being fixed on the first rotating component on the radial outer side, the dustproof cover is used for being fixed on the second rotating component on the radial inner side, the elastic sealing body is fixed on the framework, and a sealing path which is communicated with the sealing side and the outer side is formed between the elastic sealing body and the dustproof cover. The elastic sealing body has a plurality of sealing lips extending toward the dust cover, and one of the plurality of sealing lips closest to the sealing side on the sealing path is a radial sealing lip extending in the radial direction, and the radial sealing lip contacts the dust cover in parallel. Since the radial sealing lip contacts the dust cap in parallel, the radial sealing lip is not or only slightly elastically deformed, so that the friction between the radial sealing lip and the dust cap is low. Since the radial sealing lip extends in the radial direction, the axial space occupied is small, so that the sealing device can be more compact in the axial direction.

According to a preferred embodiment of the invention, the radial sealing lip can have an annular groove around the axis of rotation in the region of the surface that contacts the dust cap. The presence of the annular groove reduces the contact area between the radial sealing lip and the dust cap and increases the flexibility of the radial sealing lip, thereby further reducing friction. In addition, the annular groove can store a part of leaked lubricating grease, and the leakage is delayed. Preferably, the radial sealing lip may have a plurality of annular grooves arranged at radial intervals, and the annular grooves may be uniformly arranged in the radial direction.

According to another preferred embodiment of the present invention, the dust cap may have a first radial section extending from an end of the first axial section near the seal side toward a radially inner side, a second radial section extending from an end of the first axial section near the outer side toward a radially outer side, and a first axial section, and the radial seal lip may contact a surface of the first radial section toward the seal side in parallel. The sealing device thus constitutes a cartridge sealing device.

According to another preferred embodiment of the present invention, the plurality of seal lips may further include a main seal lip, a sub seal lip, and a second seal lip, the main seal lip and the sub seal lip may respectively extend toward the second radial section and incline toward the radial outside, and the second seal lip may extend toward the first axial section and incline toward the outside side. A plurality of seal lips form sealed cooperation with the different section cooperations of shield respectively to improve sealed effect.

According to a further preferred embodiment of the invention, the primary sealing lip may be located radially inside the secondary sealing lip and in contact with the second radial section. The primary seal lip prevents external contaminants from entering the seal side by contacting the seal face.

According to another preferred embodiment of the present invention, the elastic sealing body may have a waist portion, and the primary seal lip and the secondary seal lip may extend from the waist portion, respectively, and the secondary seal lip may be out of contact with the second radial section when the primary seal lip is in an initial installation state, and may be close to the second radial section as the primary seal lip wears when the primary seal lip wears, and may be in contact with the second radial section when the primary seal lip wears to a predetermined degree. Thus, the secondary seal lip can compensate for the loss of sealing effectiveness due to wear of the primary seal lip without excessively increasing the frictional force.

According to another preferred embodiment of the invention, the elastic sealing body may have a waist portion, and the primary sealing lip and the secondary sealing lip may each extend from the waist portion. Since the primary sealing lip cooperating with the second radial section and the secondary sealing lip cooperating with the first axial section extend from a common waist, the axial space taken up by the sealing device as a whole can be reduced.

According to a further preferred embodiment of the invention, the elastic sealing body may have an outer section extending axially radially outside the second radial section. The outer section narrows the opening of the sealing path communicating with the outer side, ensuring a sealing effect.

According to a further preferred embodiment of the invention, the dust cap may further comprise a second axial section extending from a radially inner edge of the first radial section towards the sealing side, the second axial section may be adapted to be fixed to the second rotational member.

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; and

fig. 3 shows a cross-sectional view of a sealing device according to another embodiment of the invention when mounted in a bearing.

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 between an outer ring 1 and an inner ring 2 of a cylindrical roller bearing. The outer ring 1 and the inner ring 2 are annular members arranged coaxially around the rotational axis of the bearing, wherein the outer ring 1 is located radially outside the inner ring 2. The outer ring 1 and the inner ring 2 are capable of relative rotation about the rotational axis by rolling of rolling bodies 3 arranged therebetween. In the present embodiment, the outer ring 1 serves as a first rotating member on the radially outer side, and the inner ring 2 serves as a second rotating member on the radially inner side.

As shown in fig. 1, the sealing means is installed at an axial end portion of the bearing so as to separate an inner portion of the bearing from an outer space. The space enclosed by the sealing means inside the bearing is referred to herein as the sealing side I, while the opposite external space is referred to as the external side O. The sealing device comprises a framework 4, an elastic sealing body 5 and a dust cover 6, thereby forming a box type sealing structure. The bobbin 4 is an annular member fixed at an axial end portion of the outer ring 1. The skeleton 4 is also arranged around the axis of rotation of the bearing. The skeleton 4 is made of a rigid material such as metal. The radially outer portion of the skeleton 4 may be fixed to the outer ring 1, for example, by interference fit, while the radially inner portion extends radially inwardly beyond the outer ring 1.

The dust cover 6 is also an annular member made of a rigid material such as metal. The dust cover 6 is also arranged around the axis of rotation of the bearing. As shown in fig. 1, the dust cover 6 may have four sections, as viewed in a section through the axis of rotation: a first radial section 61, a second radial section 62, a first axial section 63 and a second axial section 64. The first and second

radial sections

61, 62 extend substantially radially, while the first and second

axial sections

63, 64 extend substantially axially. The sections are all annular structures in the three-dimensional space. The first radial section 61 extends radially inward from an end of the first axial section 63 close to the seal side I, the second radial section 62 extends radially outward from an end of the first axial section 63 close to the outer side O, and the second axial section 64 extends from a radially inner edge of the first radial section 61 toward the seal side I. The dust cover 6 thus has a stepped structure, viewed in a section through the axis of rotation.

The second axial section 64 is located radially innermost of the entire dust cap 6. The second axial section 64 can be fixed to the outer side of the inner ring 2, for example, by interference fit. The first radial section 61 extends substantially in the same radial plane as the radially inner portion of the carcass 4 and is radially spaced apart. The second radial section 62 is closer to the outer side O than the radially inner portion of the skeleton 4, and extends in the radial direction to partially coincide with the radially inner portion of the skeleton 4. The first axial section 63, the second radial section 62 and the radially inner portion of the skeleton 4 thereby form a box-like space of the box seal structure.

The elastic sealing body 5 is an annular member made of an elastic material such as rubber. The elastic sealing body 5 is fixed to the frame 4 by, for example, a vulcanization process or the like. A seal path communicating the seal side I and the outside side O, that is, a path through which the lubricating grease on the seal side I leaks to the outside or contaminants on the outside side O intrude to the inside, is formed between the elastic seal body 5 and the dust cap 6.

The elastic sealing body 5 has a plurality of sealing lips extending toward the skeleton 6. As shown in fig. 2, these seal lips are formed in an annular sheet-like structure, respectively, and thus have good elasticity. One of the plurality of seal lips of the elastic seal body 5 which is closest to the seal side I on the seal path is a radial seal lip 51 extending in the radial direction. The radial sealing lip 51 contacts the side of the first radial section 61 of the dust cover 6 facing the sealing side I substantially in parallel, so that a sealing fit is formed. Since the radial sealing lip 51 is in parallel contact with the first radial section 61, the radial sealing lip 51 is not deformed substantially or only slightly. Accordingly, substantially no or only a small pressing force is generated on the contact surface of the radial seal lip 51 and the first radial section 61, and thus the frictional force between the contact surfaces is small. The radial sealing lip 51 preferably has a thickness of less than 1mm so that it can have a high flexibility.

Furthermore, one or more annular grooves 57 can be formed around the axis of rotation in the surface region of the radial sealing lip 51 which contacts the first radial section 61. The plurality of ring grooves 57 may be radially spaced apart. The annular groove 57 may reduce the contact area between the radial seal lip 51 and the first radial section 61 and increase the flexibility of the radial seal lip 51. In addition, the ring groove 57 may temporarily store the leaked lubricating grease, thereby delaying the occurrence of leakage.

The plurality of seal lips of the elastic seal body 5 further includes a primary seal lip 52 and a secondary seal lip 53 each extending toward the second radial section 62 and inclined toward the radial outside. In the present embodiment, the primary seal lip 52 and the secondary seal lip 53 are joined at the waist portion 55 of the elastic sealing body 5, in other words, the primary seal lip 52 and the secondary seal lip 53 extend from the waist portion 55, respectively. The angle of the waist 55 relative to the axial direction may be about 20 ° to 60 °. Wherein the primary seal lip 52 is located radially inward of the secondary seal lip 53. In the installed state, the primary seal lip 52 is a contact seal lip that is always in contact with the second radial section 62. In the initial installation state, each sealing lip of the elastic sealing body 5 is complete in structure, and the auxiliary sealing lip 53 is not in contact with the second radial section 62, so that clearance type sealing is formed; when the seal is in operation for a certain time, the area where the primary seal lip 52 is in contact with the second radial section 62 wears, so that the waist 55 together with the two seal lips deflects, so that the secondary seal lip 53 extends in a direction closer to the axial direction. In this process, the secondary seal lip 53 will be closer to the second radial section 62 as the primary seal lip 52 wears, and when the primary seal lip 52 wears to a certain predetermined degree, the secondary seal lip 53 will contact the second radial section 62, thereby also forming a contact seal. In the initial installation state, the sealing effect of the main sealing lip 52 is good, so that the auxiliary sealing lip 53 is kept in clearance fit with the second radial section 62, and the friction force is reduced; when the primary seal lip 52 is reduced in sealing effect due to wear, the secondary seal lip 53 and the second radial section 62 may be switched into contact engagement, thereby compensating for the loss of sealing effect of the primary seal lip 52.

The plurality of sealing lips of the elastomeric sealing body 5 further comprises a second sealing lip 54 located between the radial sealing lip 51 and the primary sealing lip 52. The second sealing lip 54 extends towards the first axial section 63 and is inclined towards the outer side O. The second sealing lip 54 serves to enhance the sealing effect and may or may not be in contact with the first axial section 63.

The elastomeric seal body 5 may also include an outer section 56 extending axially radially outward of the second radial section 62. All sealing lips are located radially inside the outer section 56. The outer section 56 further defines a box seal space, and the outer section 56 cooperates with the second radial section 62 to define an outlet of the seal path to the exterior side O.

Fig. 3 shows a sealing device according to another embodiment of the invention. The main difference of the sealing arrangement shown in fig. 3 compared to the embodiment shown in fig. 1 is that extending from the waist 55 is a primary sealing lip 52 and a secondary sealing lip 54. That is, the primary seal lip 52 is joined to the waist portion 55 together with the secondary seal lip 54, not together with the secondary seal lip 53. In this design, the axial length of the sealing means can be further reduced.

The sealing device according to the present invention prevents the leakage of the lubricating grease on the sealing side by contacting the radial seal lip of the dust cap in parallel, and can reduce friction while ensuring the sealing effect. At the same time, the radially extending sealing lip occupies less axial space, making the sealing device more compact.

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 outer ring

2 inner ring

3 rolling element

4 skeleton

5 elastic sealing body

51 radial sealing lip

52 Primary seal lip

53 auxiliary sealing lip

54 second sealing lip

55 waist part

56 outer section

57 ring groove

6 dust cover

61 first radial section

62 second radial segment

63 first axial section

64 second axial section

I sealing side

O outer side

Claims

1. A sealing arrangement for dynamic sealing between a first and a second relatively rotatable component, the sealing arrangement comprising an annular frame (4) arranged around an axis of rotation, an elastic sealing body (5) and a dust cap (6), the frame (4) being intended to be secured to the first radially outer component, the dust cap (6) being intended to be secured to the second radially inner component, the elastic sealing body (5) being secured to the frame (4), a sealing path communicating a sealing side (I) with an outer side (O) being formed between the elastic sealing body (5) and the dust cap (6),

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

the elastic sealing body (5) has a plurality of sealing lips extending toward the dust cover (6), one of the plurality of sealing lips closest to the sealing side (I) on the sealing path being a radial sealing lip (51) extending in a radial direction, the radial sealing lip (51) contacting the dust cover (6) in parallel.

2. A sealing arrangement according to claim 1, characterized in that the radial sealing lip (51) has an annular groove (57) around the axis of rotation in the area of the surface contacting the dust cap (6).

3. A sealing arrangement according to claim 2, characterized in that the radial sealing lip (51) has a plurality of said annular grooves (57) arranged radially at intervals.

4. A sealing arrangement according to claim 2, characterized in that the dust cover (6) has a first radial section (61), a second radial section (62) and a first axial section (63), the first radial section (61) extending from the end of the first axial section (63) close to the sealing side (I) towards the radially inner side, the second radial section (62) extending from the end of the first axial section (63) close to the outer side (O) towards the radially outer side, the radial sealing lip (51) contacting in parallel the surface of the first radial section (61) towards the sealing side (I).

5. The sealing arrangement, as set forth in claim 4, characterized in that the plurality of sealing lips further comprises a primary sealing lip (52), a secondary sealing lip (53) and a second sealing lip (54), the primary sealing lip (52) and the secondary sealing lip (53) respectively extending towards the second radial section (62) and being inclined towards the radial outside, the second sealing lip (54) extending towards the first axial section (63) and being inclined towards the external side (O).

6. The sealing arrangement, as set forth in claim 5, characterized in that the primary sealing lip (52) is located radially inside the secondary sealing lip (53) and is in contact with the second radial section (62).

7. The sealing arrangement as set forth in claim 6, characterized in that said elastic sealing body (5) has a waist portion (55), said primary seal lip (52) and said secondary seal lip (53) each extending from said waist portion (55), said secondary seal lip (53) being out of contact with said second radial section (62) when said primary seal lip (52) is in an initial installation condition, said secondary seal lip (53) approaching said second radial section (62) as said primary seal lip (52) wears and being capable of contacting said second radial section (62) when said primary seal lip (52) wears to a predetermined extent.

8. A sealing arrangement according to claim 6, characterized in that the elastic sealing body (5) has a waist (55), the primary sealing lip (52) and the secondary sealing lip (54) each extending from the waist (55).

9. A sealing arrangement according to claim 4, characterized in that the elastic sealing body (5) has an outer section (56) extending axially radially outside the second radial section (62).

10. The sealing arrangement according to any one of claims 4 to 9, characterized in that the dust cover (6) further comprises a second axial section (64) extending from a radially inner edge of the first radial section (61) towards the sealing side (I), the second axial section (64) being intended to be fixed on the second rotational part.