JP6718734B2 - Sealing device - Google Patents

Description

The present invention relates to a sealing device, for example, a sealing device used in an environment such as a drive system of a vehicle that is easily exposed to muddy water or the like from the outside.

Conventionally, as shown in FIG. 5, as a general sealing device 510 used in an environment where it is easily exposed to muddy water or the like from the outer side A, an inner peripheral surface 550a of a housing 550 and a rotating shaft 560 inserted into the housing 550 are used. The oil seal 520 is mounted in the annular space 570 between the outer peripheral surface 560a of the rotating shaft 560 and the dust cover 540 attached to the outer peripheral surface 560a of the rotating shaft 560 at the outer side A of the oil seal 520. It is known that the dust cover 540 has a side lip 524 slidably contacting the end surface portion 542.

According to this sealing device 510, the dust cover 540 rotates together with the rotating shaft 560, so that the leading edge 524b of the side lip 524 slidably contacts the end surface portion 542 of the dust cover 540 and the dust cover 540. By virtue of the centrifugal force shaving action in (3), the muddy water on the outside A of the machine is prevented from entering the inside B of the machine.

Further, in the sealing device 510 according to the conventional technique, the axial length of the side lip 524 is allowed to have a margin as shown by the chain double-dashed line in FIG. 5, so as to follow the axial displacement of the rotary shaft 560.

JP, 2013-113319, A

However, the sealing device 510 according to the related art may be assembled with the dust cover 540 and the oil seal 520 being closer to each other in the axial direction than the original assembly position, depending on the dimensional tolerance of the members used for assembly. Then, as shown in FIG. 6, the surface pressure between the tip edge 524b of the side lip 524 having a margin in the axial direction and the end surface portion 542 of the dust cover 540 is greatly increased, and thus the tip of the side lip 524 is increased. The edge 524b was deformed so as to be separated from the end surface portion 542 of the dust cover 540, and foreign matter such as muddy water might enter the inside B of the machine from between the tip edge 524b and the end surface portion 542.

The present invention has been made in view of the above points, and a technical problem thereof is to provide a sealing device capable of preventing deformation of the tip edge of the side lip.

As a means for effectively solving the above-mentioned technical problem, a sealing device of the present invention is mounted in an annular space between an inner peripheral surface of a housing and a rotary shaft inserted into a shaft hole formed in the housing. A sealing device comprising an oil seal and a dust cover, wherein the oil seal is an oil lip that slidably contacts the outer peripheral surface of the rotating shaft, and an end surface of the dust cover attached to the outer peripheral surface of the rotating shaft. It has a side lip in contact with the part, and the end face of the outboard of the oil seal, the deformation of the leading edge of the side lip by contact from the rear side of the side lip to the distal edge of the side lip It is characterized in that an auxiliary lip for restricting is formed. The auxiliary lip extends from the end surface on the outer side of the oil seal toward the rear surface side of the tip edge of the side lip, and the auxiliary lip is located on the side lip side in a state of not being in contact with the side lip. It may be curved so as to be convex.

Further, the deformation restricting portion forms an axial gap with the tip edge of the side lip, and when the tip edge of the side lip is deformed so as to be separated from the end surface portion of the dust cover, the side lip of the side lip is deformed. Deformation of the tip edge of the side lip may be regulated by supporting the tip edge from the back surface.

Further, the deformation restricting portion may be a protrusion protruding toward the tip edge of the side lip.

Further, the deformation restricting portion may be an annular lip formed from the end surface of the oil seal on the machine outer side toward the rear surface of the tip edge of the side lip.

According to the sealing device configured as described above, the deformation regulating portion contacts the tip edge of the side lip, so that the tip edge of the side lip can be prevented from being deformed.

It is a sectional view showing a normal assembled state of the sealing device according to the first embodiment. Dust cover and the oil seal in the sealing device according to the first embodiment is a sectional view showing a state in which close. It is a sectional view showing a normal assembled state of the sealing device according to the second embodiment. Dust cover and the oil seal in the sealing device according to the second embodiment is a sectional view showing a state in which close. It is sectional drawing of the sealing device which concerns on a prior art. FIG. 9 is a cross-sectional view showing a state in which a dust cover and an oil seal are close to each other in the sealing device according to the conventional technique.

In the following, it is described in detail with reference to the accompanying drawings a sealing device 10 according to the implementation embodiments. FIG. 1 is a cross-sectional view showing a normal assembled state of the sealing device 10 according to the first embodiment, and FIG. 2 is a state in which the dust cover 40 and the oil seal 20 in the sealing device 10 according to the first embodiment are close to each other. It is sectional drawing which shows.

As shown in FIG. 1, the sealing device 10 according to the present embodiment is an oil seal mounted in an annular space 70 between an inner peripheral surface 50a of a housing 50 and an outer peripheral surface 60a of a rotary shaft 60 inserted into the housing 50. 20 and a dust cover 40 attached to the outer peripheral surface 60a of the rotating shaft 60 on the outer side A of the oil seal 20.

The oil seal 20 is formed by integrally molding a rubber-like elastic body 22 on a metal ring 21 made of metal. Of these, the metal ring 21 has an L-shaped cross section, and extends from the tubular portion 21a concentric with the rotating shaft 60 and the axial outer side A end portion of the tubular portion 21a toward the inner diameter direction. The flange portion 21b is integrally molded. The rubber-like elastic body 22 is attached to the outer peripheral surface of the cylindrical portion 21a of the metal ring 21, and is fitted to the inner peripheral surface 50a of the housing 50 to seal the metal ring 21 and the housing 50 from each other. 22a, an end face rubber part 22b attached to the end face of the outer side A of the flange part 21b, and an inner peripheral end of the end face rubber part 22b extending toward the inner side B of the machine and sliding on the outer peripheral face 60a of the rotary shaft 60. The oil lip 22c is movably in contact with the oil lip 22c, and the dust lip 22d extends from the inner peripheral end of the end face rubber portion 22b toward the outer side A and contacts the outer peripheral surface 60a of the rotary shaft 60. On the outer peripheral surface of 22c, a garter spring 23 for applying a tightening force toward the inner diameter direction is attached. In the middle of the radial length of the end face rubber portion 22b of the oil seal 20 (in the vicinity of the end portion in the inner diameter direction of the flange portion 21b), the end face rubber portion 22b serves as the root portion 24a and extends in the opposite direction to the oil lip 22c. The side lip 24 has a conical cylindrical shape whose diameter increases toward the tip edge 24b, and the tip edge 24b slidably contacts the end surface portion 42 of the dust cover 40.

The dust cover 40 is made of metal, extends in the axial direction, is located on the outer side A with respect to the oil seal 20, and is fitted to the outer peripheral surface 60 a of the rotating shaft 60 to fix the dust cover 40 to the inner peripheral side. A cylindrical portion 41, an end surface portion 42 that develops in a disk shape from the end portion on the machine outer side A of the inner peripheral side cylindrical portion 41 toward the outer diameter direction, and an axial direction from the outer diameter direction end portion of the end surface portion 42. An outer peripheral side cylindrical portion 43 extending toward the oil seal 20 side is integrally formed.

A protrusion 30 made of a rubber-like elastic material is integrally formed with the end rubber portion 22b of the oil seal 20. The protruding portion 30 is located on the outer peripheral side of the root portion 24a of the side lip 24 and protrudes toward the tip edge 24b of the side lip 24, and its cross section has a square shape. Further, an axial gap 35 is set between the rear surface 24c of the tip edge 24b of the side lip 24 and the end portion 31 of the protrusion 30 as shown in FIG. The protrusion 30 according to the present embodiment corresponds to the deformation restricting portion described in the claims.

The sealing device 10 configured as described above brings the dust cover 40 closer to the side lip 24 of the oil seal 20 to bring the tip edge 24b of the side lip 24 into contact with the end surface portion 42 of the dust cover 40. As a result, the dust cover 40 is attached to the oil seal 20. Then, the sealing device 10 according to the present embodiment exhibits the following functions depending on the assembly position of the dust cover 40 and the oil seal 20.

That is, when the dust cover 40 and the oil seal 20 are in the original assembly position, the tip edge 24b of the side lip 24 slidably contacts the end surface portion 42 of the dust cover 40 as shown in FIG. On the other hand, the protrusion 30 does not contact the back surface 24c of the tip edge 24b of the side lip 24, and forms an axial gap 35 with the back surface 24c of the tip edge 24b. On the other hand, when the dust cover 40 and the oil seal 20 are assembled in a state in which they are close to each other in the axial direction, the tip edge 24b of the side lip 24 is slidable with the end surface portion 42 of the dust cover 40 as shown in FIG. To contact. The end 31 of the protrusion 30 contacts the back surface 24c of the tip edge 24b of the side lip 24, and the tip edge 24b of the side lip 24 deforms only up to the position of contacting the end 31 of the protrusion 30. I can't.

As described above, according to the sealing device 10 of the present embodiment, the tip edge 24b of the side lip 24 of the oil seal 20 slidably contacts the end surface portion 42 of the dust cover 40, and the centrifugal force of the dust cover 40 is increased. By exerting the shake-off action of, the muddy water on the outside A of the machine is prevented from entering the inside B of the machine.

In addition, when the dust cover 40 and the oil seal 20 are in the original assembling position, the protrusion 30 does not come into contact with the back surface 24c of the tip edge 24b of the side lip 24, so that the tip edge 24b of the side lip 24 relative to the dust cover 40. Surface pressure does not rise. Therefore, the sliding torque of the tip edge 24b of the side lip 24 is equal to the sliding torque of the sealing device 510 according to the conventional technique.

In addition, when the dust cover 40 and the oil seal 20 are assembled in a state in which they are close to each other in the axial direction, the axial gap 35 between the rear surface 24c of the tip edge 24b of the side lip 24 and the end 31 of the protrusion 30 is formed. Disappears, and the tip edge 24b of the side lip 24 can be deformed only up to the position where it contacts the end 31 of the protrusion 30. Therefore, it is possible to prevent the tip edge 24b of the side lip 24 from being deformed away from the end surface portion 42 of the dust cover 40, and thus the end surface portion 42 of the dust cover 40 and the tip edge 24b of the side lip 24 are separated from each other. It is possible to prevent foreign matter such as muddy water from entering the inside B of the machine from the gap.

Next, the sealing device 10 according to the second embodiment will be described in detail with reference to the drawings. FIG. 3 is a cross-sectional view showing a normal assembled state of the sealing device 10 according to the second embodiment, and FIG. 4 is a state in which the dust cover 40 and the oil seal 20 in the sealing device 10 according to the second embodiment are close to each other. It is sectional drawing which shows.

That is, in the sealing device 10 according to the present embodiment, the annular auxiliary lip 32 made of a rubber-like elastic material is integrally formed with the end surface rubber portion 22b of the oil seal 20. The base portion 33 of the auxiliary lip 32 is located on the outer peripheral side of the root portion 24a of the side lip 24, and has a conical cylindrical shape whose diameter increases from the base portion 33 of the auxiliary lip 32 toward the tip edge 24b of the side lip 24. It is a thing. Further, as shown in FIG. 3, an axial gap 35 is set between the back surface 24c of the tip edge 24b of the side lip 24 and the tip portion 34 of the auxiliary lip 32, and the auxiliary lip 32 is dusty. It is set so as to exert an elastic restoring force toward the end surface portion 42 of the cover 40. The auxiliary lip 32 according to the present embodiment corresponds to the deformation restricting portion described in the claims.

The sealing device 10 having the above configuration brings the dust cover 40 close to the side lip 24 of the oil seal 20 to bring the tip edge 24b of the side lip 24 into contact with the end surface portion 42 of the dust cover 40. As a result, the dust cover 40 is attached to the oil seal 20. Then, the sealing device 10 according to the present embodiment exhibits the following functions depending on the assembly position of the dust cover 40 and the oil seal 20.

That is, when the dust cover 40 and the oil seal 20 are in the original assembly position, the leading edge 24b of the side lip 24 slidably contacts the end surface portion 42 of the dust cover 40 as shown in FIG. On the other hand, the tip end portion 34 of the auxiliary lip 32 does not come into contact with the back surface 24c of the tip edge 24b of the side lip 24, and the tip end portion 34 of the auxiliary lip 32 and the back surface 24c of the tip edge 24b of the side lip 24 do not contact each other. A directional gap 35 is formed. On the other hand, when the dust cover 40 and the oil seal 20 are assembled so as to be close to each other in the axial direction, the tip edge 24b of the side lip 24 is deformed so as to be separated from the end surface portion 42 of the dust cover 40, as shown in FIG. Thus, the tip edge 24 b of the side lip 24 contacts the tip portion 34 of the auxiliary lip 32. Since the auxiliary lip 32 exerts an elastic restoring force toward the end surface portion 42 of the dust cover 40, the tip portion 34 of the auxiliary lip 32 presses the tip edge 24b of the side lip 24.

As described above, according to the sealing device 10 of the present embodiment, the tip edge 24b of the side lip 24 of the oil seal 20 slidably contacts the end surface portion 42 of the dust cover 40, and the centrifugal force of the dust cover 40 is increased. By exerting the shake-off action of, the muddy water on the outside A of the machine is prevented from entering the inside B of the machine.

In addition, when the dust cover 40 and the oil seal 20 are in the original assembly position, the tip portion 34 of the auxiliary lip 32 does not come into contact with the back surface 24c of the tip edge 24b of the side lip 24, so that the side lip 24 with respect to the dust cover 40 is in contact. The surface pressure of the tip edge 24b of the above does not rise. Therefore, the sliding torque of the tip edge 24b of the side lip 24 is equal to the sliding torque of the sealing device 510 according to the conventional technique.

In addition, when the dust cover 40 and the oil seal 20 are assembled in the axially close state, the tip edge 24b of the side lip 24 is pressed by the elastic restoring force of the auxiliary lip 32. Therefore, it is possible to prevent the tip edge 24b of the side lip 24 from being deformed away from the end surface portion 42 of the dust cover 40, and thus the end surface portion 42 of the dust cover 40 and the tip edge 24b of the side lip 24 are separated from each other. It is possible to prevent foreign matter such as muddy water from entering the inside B of the machine from the gap.

Further, since the auxiliary lip 32 according to the present embodiment has a shape that extends in the outer diameter direction, it can be easily elastically deformed. Therefore, the force with which the auxiliary lip 32 presses the tip edge 24b of the side lip 24 can be reduced, and thus energy loss and the like due to an increase in the sliding torque of the side lip 24 can be suppressed.

The protrusion 30 according to the present embodiment may be annular, and a plurality of protrusions 30 may be formed at predetermined intervals in the circumferential direction.

10 Sealing device 20 Oil seal 21 Metal ring 21a Cylindrical part 21b Flange part 22 Rubber-like elastic body 22a Outer peripheral seal part 22b End surface rubber part 22c Oil lip 22d dust lip 23 Garter spring 24 Side lip 24a Root part 24b Tip edge 24c Rear surface 30 Protrusion 31 End 32 Auxiliary Lip 33 Base 34 Tip 35 Axial Gap 40 Dust Cover 41 Inner Circular Cylinder 42 End Face 43 Outer Circular Cylinder 50 Housing 50a Inner Surface 60 Rotating Shaft 60a Outer Surface 70 Annular Space Outside of machine A Inside of machine B

Claims (3)

A sealing device comprising an oil seal and a dust cover mounted in an annular space between an inner peripheral surface of a housing and a rotary shaft inserted into a shaft hole formed in the housing,
The oil seal has an oil counter lip that slidably contacts the outer peripheral surface of the rotating shaft, and a side lip that contacts the end surface portion of the dust cover attached to the outer peripheral surface of the rotating shaft,
Wherein the end face of the outboard side of the oil seal are the leading edge auxiliary lip to restrict the deformation of the formation of the side lip by contact from the rear side of the side lip to the distal edge of the side lip,
The auxiliary lip extends from the end surface on the outer side of the oil seal toward the rear surface side of the tip edge of the side lip, and the auxiliary lip is located on the side lip side in a state of not being in contact with the side lip. A sealing device which is curved so as to be convex . The sealing device according to claim 1,
The auxiliary lip forms an axial gap with the tip edge of the side lip,
When the tip edge of the side lip is deformed so as to be separated from the end surface portion of the dust cover, the tip edge of the side lip is supported from the back surface to restrict the deformation of the tip edge of the side lip. Sealing device. The sealing device according to claim 1 or 2, wherein the auxiliary lip has a conical cylindrical shape whose diameter increases from a base portion toward the tip edge of the side lip.

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