WO2018149274A1 - Lip seal - Google Patents

Abstract

A lip seal comprises an annular main body (10) and sealing lips (20, 30) surrounding the main body (10). The sealing lips (20, 30) have tip portions (21, 31) for contact and sealing and opening portions (22, 32) which open in an axial direction. Protection members (50) are securely provided at the sealing lips (20, 30). The protection members (50) have protection layers (51) covering the tip portions (21, 31). The protection layers (51) extend in the axial direction from the tip portions (21, 31) toward the opening direction of the opening portions (22, 32). Moreover, the protection layers (51) form an annulus coaxial with the sealing lips (20, 30). The lip seal can prevent sealing performance of the sealing lips from deteriorating due to wear.

Description

Lip seal

The present application claims priority to Chinese Patent Application, filed Jan.

Technical field

The present invention relates to the field of sealing, and in particular to a lip seal.

Background technique

The lip seal is a self-sealing contact seal that is widely used between relatively moving mechanical components, such as a housing and a rotating shaft that is threaded through the housing. Taking an engine or a gearbox as an example, in order to achieve heat dissipation or lubrication, a lubricant or a coolant is usually provided in the housing, and a lip seal is mounted on the housing and sleeved outside the rotating shaft to isolate the inside of the housing from the outside. To achieve internal sealing and external dustproof effect.

The lip seal is able to operate well in a clean coolant or lubricant environment. However, due to the influence of the manufacturing process, storage and transportation environment, the surface of each mechanical component inevitably adheres to metal particles or other particle impurities. When these particles enter the lubricant or coolant, they will follow the rotation axis. Gathering around the sealing lip of the lip seal causes wear on it, resulting in failure of the seal of the lip seal.

Summary of the invention

The problem addressed by the present invention is that existing lip seals typically fail due to wear of particulate impurities in the coolant or lubricant.

In order to solve the above problems, the present invention provides a lip seal comprising an annular body and a sealing lip surrounding the body, the sealing lip having a lip for contacting the seal and a lip opening toward the axial end a protective member is disposed on the sealing lip, the protective member has a protective layer covering the lip tip, and the protective layer extends axially from the lip tip to the opening direction of the lip, and A ring that is coaxial with the sealing lip.

Optionally, the sealing lip further includes a first surface and a second surface respectively located on two axial sides of the lip tip, where the first surface and the second surface intersect to form the lip tip; In the first surface, the second surface is axially closer to the lip of the sealing lip, and the protector is fixed to the first surface.

Optionally, the protective layer is provided with a groove on an end surface away from one end of the lip tip.

Optionally, the grooves have a plurality of grooves arranged in the circumferential direction.

Optionally, a plurality of the grooves are circumferentially connected to form a waveform.

Optionally, the sealing lip has a plurality of sealing lips corresponding to one of the protective layers.

Optionally, among the plurality of the sealing lips, the opening of the lip of a part of the sealing lip faces the one end in the axial direction, and the opening of the lip of the other part of the sealing lip faces the other end in the axial direction.

Optionally, the protective layer on each of the sealing lips is integrally formed on the same protective member.

Optionally, the protection member is vulcanized to the sealing lip.

Optionally, the protection member has a lower coefficient of friction than the rubber.

Optionally, the protection member is polytetrafluoroethylene.

Compared with the prior art, the technical solution of the present invention has the following advantages:

The sealing lip of the solution is provided with a protective member having a protective layer covering the lip tip and having an annular shape, and the protective layer extends axially from the lip tip of the sealing lip to the opening of the lip.

After the lip seal is sleeved on the rotating shaft, the sealing lip is pressed on the outer peripheral surface of the rotating shaft, and the protective layer is parallel to the rotating shaft and is in contact with the outer peripheral surface of the rotating shaft to separate the rotating shaft from the lip of the sealing lip. Open, avoiding the contact of the lip tip with the rotating shaft, thereby avoiding the wear of the sealing lip in frictional contact with the particles.

Further, a groove is provided on an end surface of the protective layer away from the end of the lip tip of the sealing lip, and when the lip seal is mounted on the rotating shaft, the fluid (for example, lubricant, coolant or air) in the groove is concave The grooves act in a circumferential direction relative to the lip seal, whereby particles accumulated in the vicinity of the protective layer can be detached from the protective layer, thereby ensuring cleaning of the fluid environment near the sealing lip to further avoid wear of the sealing lip.

DRAWINGS

Figure 1 is a cross-sectional view showing a lip seal of a first embodiment of the present invention in a three-dimensional state;

Figure 2 is a cross-sectional view of a lip seal of a first embodiment of the present invention;

Figure 3 is an exploded view of the first sealing lip and the protective member of the lip seal of the first embodiment of the present invention;

Figure 4 is a cross-sectional view of a lip seal of a second embodiment of the present invention;

Figure 5 is a cross-sectional view of a lip seal of a third embodiment of the present invention.

detailed description

The above described objects, features, and advantages of the present invention will be more apparent from the aspects of the invention.

First embodiment

The present embodiment provides a lip seal comprising an annular body 10 and a sealing lip surrounding the body 10, as shown in Figures 1-3. Wherein, for the lip seal, the number of the sealing lips may be one or more. When there are a plurality of sealing lips, the opening directions of the lips of the respective sealing lips may be the same or vice versa.

The lip seal shown in FIG. 1 and FIG. 2 includes two sealing lips and are located on the radially inner side of the main body 10, respectively defined as a first sealing lip 20 and a second sealing lip 30, wherein the first sealing lip 20 The opening of the lip of the second sealing lip 30 is opposite. The lip seal can be used to be sleeved on a rotating shaft (not shown), and the main body 10 is fixed on the non-rotating member, and the first sealing lip 20 and the second sealing lip 30 are in contact with the outer peripheral surface of the rotating shaft. Dynamic seal. A skeleton 11 may be embedded in the interior of the main body 10 for reinforcing the strength of the main body. In this embodiment, the sealing lip is disposed radially inward of the lip seal to form a seal with the rotating shaft disposed in the lip seal. In other embodiments, the sealing lip may also be disposed radially outward of the lip seal to form a seal with the rotating component that is sleeved outside the lip seal.

Wherein the first sealing lip 20 has a first lip 21 for contacting the seal and a first lip 22 opening toward the axial end, the second sealing lip 30 having a second lip 31 for contacting the seal and facing the shaft A second lip 32 that opens to the other end. The opening direction of the first lip 22 faces the sealing cavity requiring sealing, and the opening direction of the second lip 32 is directed away from the sealing cavity. Thus, the first sealing lip 20 serves as a main sealing lip, which can be used to seal the lubricant or coolant inside the sealing cavity to prevent leakage thereof; the second sealing lip 20 serves as a secondary sealing lip and can be used for the sealing cavity. Impurities such as dust and water vapor outside the body are blocked to prevent them from entering the sealed cavity.

The coil spring 40 can be embedded coaxially in the first sealing lip 20. When the lip seal is sleeved on the rotating shaft, the coil spring 40 provides a tensioning force to press the first sealing lip 20 on the rotating shaft.

As shown in FIG. 1 and FIG. 2 , a protective member 50 is disposed on the first sealing lip 20 , and the protective member 50 has a protective layer 51 covering the first lip 21 . The protective layer 51 is coaxial with the first sealing lip 20 . Ring. The protective layer 51 extends in the axial direction from the first lip tip 21 toward the opening direction of the first lip 22, and as can be seen from FIG. 2, the protective layer 51 extends rightward from the first lip tip 21.

When the lip seal is sleeved on the rotating shaft, the first sealing lip 20 is press-fitted on the outer peripheral surface of the rotating shaft, and the protective layer 51 is parallel to the rotating shaft and is in contact with the outer peripheral surface of the rotating shaft. Thereby, the protective layer 51 separates the rotating shaft from the first lip 21 of the first sealing lip 20, and the first lip 21 does not contact the rotating shaft, and the first sealing lip 20 can be prevented from being in the lubricant or the coolant. The particles are in contact with the friction and wear.

The first sealing lip 20 is a rubber member. In order to avoid increasing the contact friction between the lip seal and the rotating shaft, the protective member 50, particularly the protective layer 51, has a lower coefficient of friction than the rubber. In this embodiment, the protective member 50 is formed of polytetrafluoroethylene. The self-lubricating properties of PTFE can effectively reduce the friction between the lip seal and the rotating shaft.

In this embodiment, the protective member 50 is fixed to the first sealing lip 20, and its fixed position at the first sealing lip 20 is preferably on the side of the first lip 21 facing away from the sealing cavity. As shown in FIG. 3, the first sealing lip 20 includes a first surface 23 and a second surface 24 respectively located on both axial sides of the first lip tip 21, and the first surface 23 and the second surface 24 intersect to form a first portion. Lip tip 21. The second surface 24 is closer to the first lip 22 of the first sealing lip 20 in the axial direction than the first surface 23, and the protective member 50 is fixed to the first surface 23.

Specifically, the protective member 50 has a fixing layer 52 fixed to the first surface 23, and the fixing layer 52 may be vulcanized in the rubber member of the first sealing lip 20 by a vulcanization process.

Second embodiment

The difference between this embodiment and the first embodiment is that, as shown in FIG. 4, the protective layer 51 is provided with a recess 53 on the end surface away from the end of the first lip tip 21. As can be seen from FIG. 4, the groove 53 is provided at the end face of the free end of the protective layer 51.

A groove 53 is provided in the protective layer 51. When the lip seal is mounted on the rotating shaft, the groove 53 faces the sealing cavity and is in contact with the lubricant or the coolant in the sealing cavity, and drives the lubricant when the rotating shaft rotates. Or the coolant rotates relative to the protective layer 51. The lubricant or the coolant collides with the groove wall of the groove 53 due to the relative movement, thereby flowing away from the protective layer under the action of the collision force, so that the particles accumulated at the free end of the protective layer flow in a direction away from the protective layer. Thereby, the groove 53 can act to pump the lubricant or coolant located in the groove 53 in a direction away from the first lip tip 22 to move the lubricant or coolant in the groove 53 away from the lip. The seal is pumped, whereby particles accumulated in the vicinity of the protective layer 51 can be separated from the protective layer 51, thereby ensuring cleaning of the fluid environment in the vicinity of the first sealing lip 20 to further avoid wear of the first sealing lip 20.

The number of the grooves 53 may be set as needed, and may be one or more. In the present embodiment, the grooves 53 have a plurality of grooves arranged in the circumferential direction and are connected in a circumferential direction in a wave shape. As shown in FIG. 4, the free end of the protective layer 51 has a corrugated shape which is undulating in the circumferential direction, wherein each of the troughs is formed as a groove 53, and the wall surface of the groove 53 is curved.

In other embodiments, the shape of the groove 53 may also be a square groove, a triangular groove or a groove of other shapes, and the shape of the groove is not limited as long as it is recessed at the end surface of the free end of the protective layer.

Third embodiment

The difference between this embodiment and the first embodiment and the second embodiment is that, as shown in FIG. 5, the protection member 50 extends from the first sealing lip 20 to the second sealing lip 30, and the protective member 50 simultaneously covers the second lip tip 31. . When the lip seal is sleeved on the rotating shaft, the protector 50 contacts the rotating shaft instead of the second lip 31 to protect the second sealing lip 30 from frictional wear.

As shown in FIG. 5, the protective member 50 is simultaneously vulcanized on the first sealing lip 20 and the second sealing lip 30.

In other embodiments, the first sealing lip and the second sealing lip may respectively be provided with protective members that are separated from each other (ie, independent of each other), and are formed to protect the first lip tip and the second lip tip respectively. Floor. Wherein, the end faces of the free ends of the protective layers corresponding to the first lip tip and the second lip tip may be planar or provided with grooves.

Although the present invention has been disclosed above, the present invention is not limited thereto. Any changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be determined by the scope defined by the appended claims.

Claims (10)

A lip seal comprising an annular body and a sealing lip surrounding the body, the sealing lip having a lip for contacting the seal and a lip opening toward the axial end; The sealing lip is fixed with a protective member, and the protective member has a protective layer covering the lip tip, and the protective layer extends from the lip tip to the opening direction of the lip in the axial direction. And in a ring shape coaxial with the sealing lip. The lip seal according to claim 1, wherein said sealing lip further comprises a first surface, a second surface, respectively, on said axial sides of said lip tip, said first surface, said second The portion where the surfaces intersect forms the lip tip; The second surface is axially closer to the lip of the sealing lip than the first surface, and the protector is fixed to the first surface. The lip seal of claim 1 wherein said protective layer is provided with a recess on an end surface remote from an end of said lip. A lip seal according to claim 3, wherein said groove has a plurality of circumferentially arranged. A lip seal according to claim 4, wherein a plurality of said grooves are circumferentially connected in a wave shape. A lip seal according to any one of claims 1 to 5, wherein the sealing lip has a plurality of one, and one of the sealing lips corresponds to one of the protective layers. A lip seal according to claim 6, wherein, among the plurality of said sealing lips, the opening of the lip of a part of the sealing lip faces one end in the axial direction, and the opening of the lip of the other part of the sealing lip faces the axial direction. One end. A lip seal according to claim 6, wherein said protective layer on each of said sealing lips is integrally formed on the same protective member. The lip seal of claim 1 wherein said protective member has a lower coefficient of friction than rubber. The lip seal of claim 1 wherein said protective member is polytetrafluoroethylene.

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