CN113757379A

CN113757379A - Sealing device

Info

Publication number: CN113757379A
Application number: CN202110962446.2A
Authority: CN
Inventors: 刘鑫; 张岳林
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2021-12-07

Abstract

The present invention relates to a sealing device. The sealing arrangement comprises an annular frame arranged around the axis of rotation and an elastic sealing body which is fixed to the frame and comprises at least one sealing lip extending radially inwards, the elastic sealing body separating a first sealing side and a second sealing side in the axial direction. Wherein the elastomeric seal body further comprises at least one wiper lip extending towards the radially inner side, each wiper lip having an elongated strip-like structure and being axially closer to the first sealing side than the at least one seal lip. The sealing device of the present invention has an improved sealing effect.

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 dynamic sealing.

Background

Sealing devices are required to be installed in the rotating parts of many machines. These seals are generally annular in shape and include a rigid backbone and an elastomeric seal body. The frame is made of a metal material so as to be fixed to the radially outer rotating member by interference fit. The elastomeric seal body is secured to the frame and extends beyond one or more of the seal lips. These sealing lips may form a sealing engagement with the radially inner further rotating part. Some of the sealing lips can be pressed against the surface of the sealed off piece by means of an annular spring. A sealing device having such a typical structure is disclosed in patent documents CN 104747726 a and the like, for example.

In a vehicle hub or the like application scenario, the two sides of the seal may be different liquid environments, e.g. oil on one side and grease on the other side. However, sometimes the oil is not necessarily absolutely clean, for example there may be many metal particles from the transmission in the oil. Metal particles may enter the interface between the seal lip and the sealed piece, causing wear of the seal lip. Due to this wear, conventional sealing devices of this type may rapidly fail, resulting in leakage.

Disclosure of Invention

Therefore, the technical problem to be solved by the present invention is to provide a sealing device capable of improving the sealing effect.

The above-mentioned technical problem is solved by a sealing device according to the present invention. The sealing arrangement comprises an annular frame arranged around the axis of rotation and an elastic sealing body which is fixed to the frame and comprises at least one sealing lip extending radially inwards, the elastic sealing body separating a first sealing side and a second sealing side in the axial direction. Wherein the elastomeric seal body further comprises at least one wiper lip extending towards the radially inner side, each wiper lip having an elongated strip-like structure and being axially closer to the first sealing side than the at least one seal lip. The elongated configuration of the wiping lip is such that it creates a wiping effect when rotating with the radially outer sealed piece, forcing contaminants, in particular particulate contaminants, that are close to the sealing lip from the first sealing side away from the sealing lip, thereby reducing the risk of contaminants from the first sealing side penetrating into the second sealing side. Therefore, the sealing device is mainly suitable for application scenes with different working conditions at two axial sides, and is particularly beneficial to protecting the sealing lip and prolonging the service life of the sealing device under the condition that more particle pollutants are likely to be generated at the first sealing side.

According to a preferred embodiment of the present invention, the at least one sweeping lip may comprise a plurality of sweeping lips circumferentially spaced apart. Preferably, the plurality of sweeping lips are evenly distributed in the circumferential direction. The sweeping lips distributed along the circumferential direction enable the capability of the sealing device for sweeping away particle pollutants to be obviously improved, and the good antifouling effect is achieved in the whole circumferential direction.

According to another preferred embodiment of the invention, each sweeping lip may taper from the root to the free end. This allows the wiping lip to have a gradually increasing elasticity from the root to the free end, which is more easily elastically deformed during rotation, resulting in a better wiping effect.

According to a further preferred embodiment of the invention, the free end of each wiper lip, in a section through the axis of rotation, can be inclined with respect to the radial direction towards the first sealing side. This allows the sweeping lip to have a longer extension and a better sweeping effect.

According to a further preferred embodiment of the invention, each sweeping lip may have a rectangular cross-sectional profile. The sweeping lip with the shape is easier to process and contributes to reducing the production cost.

According to a further preferred embodiment of the invention, the free end of each wiper lip is able to contact the radially inner sealed piece in the mounted state. This results in no radial clearance between the wiper lip and the radially inner sealed member, further reducing the likelihood of particulate contaminants from intruding into the seal lip.

According to a further preferred embodiment of the invention, the at least one sealing lip may comprise an annular main sealing lip which is closest to the first sealing side in the axial direction, the main sealing lip being intended to contact the radially inner sealed piece. The primary sealing lip prevents liquid from leaking between the first sealing side and the second sealing side by contact sealing. Preferably, the sealing device may further include an annular spring mounted radially outward of the primary seal lip and pressing the primary seal lip radially inward to improve the tightness of fit between the primary seal lip and the sealed member.

According to a further preferred embodiment of the invention, the at least one sealing lip may further comprise an annular secondary sealing lip which is closest to the second sealing side in the axial direction, a free end of which may extend obliquely towards the radial inner side and towards the first sealing side. Since most of the particulate contaminants are swept away by the sweep lip, less particulate contaminants can penetrate from the first seal side to the secondary seal lip, and therefore the secondary seal lip is less worn and the service life is improved.

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 sealing device according to an exemplary embodiment of the present invention; and

fig. 2 shows a perspective view of a sealing device according to an exemplary embodiment of the present invention.

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. The seal is adapted to be mounted in an annular space between two relatively rotatable components for dynamic sealing, for example between an outer race and an inner race of a bearing.

Fig. 1 and 2 show an exemplary embodiment of a sealing device according to the invention. Fig. 1 shows a cross-sectional view of a sealing device according to the present embodiment. The sealing device is annular as a whole. In fig. 1, the sealing device is mounted in the annular space between two rotating parts. The two rotating parts may be, for example, the outer ring 10 and the inner ring 20 of the bearing. The outer ring 10 and the inner ring 20 are relatively rotatable about an axis of rotation. The sealing device is also arranged around an axis of rotation, the central axis of which substantially coincides with the axis of rotation. The section shown in fig. 1 is a section through the axis of rotation.

As shown in fig. 1, the seal assembly includes a skeletal frame 30 and an elastomeric seal body 50. The frame 30 is an annular member arranged around the rotational axis, and is made of a rigid material such as metal. The cage 30 is fixed to a radially outer rotating member, and in the present embodiment, the cage 30 may be fixed to a radially inner side of the outer ring 10 by interference fit, for example, so as to be rotatable together with the outer ring 10 relative to the inner ring 20.

The elastic sealing body 50 is also an annular member arranged around the rotational axis, and is made of an elastic material such as rubber. The elastic sealing body 50 is fixed to the frame 30 by, for example, vulcanization. The elastomeric seal body 50 includes a base 51 for securing to the armature 30 and at least one sealing lip extending from the base 51. The sealing lips of the elastic sealing body 50 each have an annular configuration about the axis of rotation. In the present embodiment, two seal lips, a primary seal lip 52 and a secondary seal lip 53, are schematically shown. In the mounted state, the primary seal lip 52 and the secondary seal lip 53 each extend toward the radially inner ring 20, and form a sealing engagement with the outer surface of the inner ring 20. Wherein at least the primary seal lip 52 contacts the outer surface of the inner race 20.

In order to provide a closer fit of the primary seal lip 52 against the outer surface of the inner race 20, the seal may also include an annular spring 40. The spring 40 surrounds the primary seal lip 52 radially outward and presses the primary seal lip 52 radially inward, so that the primary seal lip 52 abuts tightly on the inner race 20.

The secondary seal lip 53 may be an annular sheet seal lip, and a free end of the secondary seal lip 53 may extend obliquely toward the radially inner side and toward one side of the primary seal lip 52 as viewed in a cross section passing through the rotational axis. By these seal lips, the elastic seal body 50 is partitioned in the axial direction into a first seal side S1 close to the primary seal lip 51 and a second seal side S2 close to the secondary seal lip 53.

In the seal arrangement according to the invention, the elastomeric seal body 50 also includes a wiper lip 54. The wiper lip 54 is an elongated strip-like structure extending radially inward from the elastomeric seal body 50. The wiper lip 54 is a resilient structure integrally formed with the resilient seal body 50. The elastomeric seal body 50 may include one or more wiper lips 54. When the elastomeric seal body 50 includes a plurality of wiper lips 54, the wiper lips 54 may be circumferentially spaced, and particularly circumferentially evenly spaced. The wiper lip 54 is axially closer to the first sealing side S1 than all the seal lips.

Fig. 2 shows a perspective view of the sealing device. As shown in fig. 2, each wiper lip 54 extends substantially in a plane passing through the axis of rotation, that is to say without inclination in the circumferential direction. Meanwhile, as shown in fig. 1, in a cross section passing through the rotational axis, the free end of each sweeping lip 54 is inclined toward the first sealing side S1 with respect to the radial direction. When the bearing is installed in, for example, a hub of a truck, liquid may be present in both the first sealing side S1 and the second sealing side S2, grease is typically present in the second sealing side S2 inside the bearing, and oil and particulate contaminants, such as swarf from friction, etc., may be present in the first sealing side S1 outside the bearing. Since the wiper lip 54 is closer to the first sealing side S1 than all the seal lips, particulate contaminants can be blocked before they invade the seal lips. When there is relative rotation between the outer ring 10 and the inner ring 20, there is also relative rotation between the sealing means fixed to the outer ring 10 and the inner ring 20. The rotating wiper lip 54 creates a wiping effect such that particulate contaminants near the seal lip move toward the first sealing side S1 and thus away from the seal lip. Since the wiping lip 54 has elasticity, it is deformed obliquely in the circumferential direction during rotation, thereby further improving the wiping effect.

Preferably, the free end of the wiper lip 54 is able to contact the radially inner sealed element, i.e. the inner ring 20 in this embodiment, in the mounted state. Therefore, there is no gap between the free end of the sweeping lip 54 and the inner ring 20 in the radial direction, thereby effectively sweeping particulate contaminants on the surface of the inner ring 20.

Preferably, each wiper lip 54 tapers from the root towards the free end, i.e. the cross-sectional area becomes smaller. This makes the wiping lip 54 more elastic as it approaches the free end, and is more likely to be elastically deformed, so that the wiping effect can be improved. The cross-sectional profile of the wiping lip 54 may be rectangular. The cross section here refers to a section perpendicular to the elongate extension of the wiper lip 54. Furthermore, the free end of the wiper lip 54 may have a flat end surface. The wiper lip 54 of this configuration is easier to machine.

The sealing device of the invention eliminates the particle pollutants close to the sealing lip from the first sealing side S1 through the sweeping lip 54, reduces or even avoids the possibility that the particle pollutants invade the sealing lip and the second sealing side S2, thereby reducing the abrasion of the sealing lip and effectively improving the service life and the sealing effect of the sealing device.

It is noted that the present invention is intended to remove particle contamination close to the sealing lip by means of the wiping lip closest to one sealing side, and therefore the solution of the present invention can be applied to all kinds of possible sealing arrangements where there is wear by particle contamination. In this case, the specific shape and number of the seal lips may be variously changed, and are not limited to the types described in the embodiments and shown in the drawings.

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

10 outer ring

20 inner ring

30 framework

40 spring

50 elastic sealing body

51 base

52 Primary seal lip

53 auxiliary sealing lip

54 sweeping lip

S1 first sealing side

S2 second sealing side

Claims

1. A sealing arrangement comprising an annular skeleton (30) arranged about an axis of rotation and an elastic sealing body (50), the elastic sealing body (50) being fixed to the skeleton (30) and comprising at least one sealing lip extending towards a radially inner side, the elastic sealing body (50) axially separating a first sealing side (S1) and a second sealing side (S2),

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

the elastomeric seal body (50) further includes at least one wiper lip (54) extending radially inward, each wiper lip (54) having an elongated strip-like configuration and being axially closer to the first seal side than the at least one seal lip (S1).

2. The sealing arrangement of claim 1, wherein the at least one wiper lip (54) includes a plurality of wiper lips (54) spaced circumferentially.

3. The sealing arrangement according to claim 2, characterized in that the plurality of wiping lips (54) are evenly distributed in the circumferential direction.

4. A sealing arrangement according to claim 1, characterized in that each wiper lip (54) tapers from a root portion to a free end.

5. Sealing arrangement according to claim 1, characterized in that in a section through the axis of rotation the free end of each wiper lip (54) is inclined with respect to the radial direction towards the first sealing side (S1).

6. The sealing arrangement according to claim 1, characterized in that each wiper lip (54) has a rectangular cross-sectional profile.

7. A sealing arrangement according to claim 1, characterized in that the free end of each wiper lip (54) is able to contact the radially inner sealed piece in the mounted state.

8. The sealing arrangement according to any one of claims 1 to 7, characterized in that the at least one sealing lip comprises an annular main sealing lip (52) closest to the first sealing side (S1) in the axial direction, the main sealing lip (52) being adapted to contact a radially inner sealed piece.

9. The sealing arrangement according to claim 8, characterized in that the sealing arrangement further comprises an annular spring (40), the spring (40) being mounted radially outside the primary sealing lip (52) and pressing the primary sealing lip (52) radially inside.

10. The sealing arrangement, as set forth in claim 9, characterized in that the at least one sealing lip further comprises an annular secondary sealing lip (53) closest to the second sealing side (S2) in the axial direction, the free end of the secondary sealing lip (53) extending obliquely towards the radial inside and towards the first sealing side (S1).