JP2021167641A - Sealing device - Google Patents

Abstract

To provide a sealing device capable of suppressing a side lip from being turned over in installation.SOLUTION: A side lip 124 has a belly part 124b whose diameter increases as fluid to be sealed moves from a sealed region side to the opposite side, and a tip part 124c provided on the tip side of the belly part 124b, and is configured such that the belly part 124b has a greater degree of diameter expansion than the tip part 124c. On the outer peripheral surface of the side lip 124, a plurality of protrusions 124d provided so as to straddle the boundary between the belly part 124b and the tip part 124c is provided at intervals in a circumferential direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sealing device that seals an annular gap between a rotating shaft and a housing.

In various devices such as a differential device, a sealing device for sealing an annular gap between the rotating shaft and the housing is provided. A sealing device according to a conventional example will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view of the sealing device according to the conventional example. The illustrated sealing device 500 is provided in the differential mechanism in the differential device.

The sealing device 500 includes a reinforcing ring 510 and an elastic sealing device main body 520 integrally provided on the reinforcing ring 510. The sealing device main body 520 includes an outer peripheral sealing portion 521 and a seal lip slidably provided with respect to the rotating shaft 200. In this illustrated example, the seal lip is provided with a main lip 522 and a dust strip 523. Further, the sealing device main body 520 also includes a side lip 524 slidably provided on the end surface of the deflector 300, which is a rotating member that rotates together with the rotating shaft 200. The side lip 524 is configured such that its inner peripheral surface side slides with respect to the deflector 300 as shown by the side lip 524a shown by the dotted line in the drawing.

However, when the sealing device 500 is incorporated into the rotating shaft 200, the side lip 524 may be turned over as shown by a solid line in the drawing. That is, the assembling work is performed so that the rotating shaft 200 is relatively inserted from the left side to the right side in the drawing with respect to the sealing device 500. In this process, the deflector 300 abuts on the tip of the side lip 524, and the rotating shaft 200 is further inserted, so that the tip of the side lip 524 usually bends while sliding with respect to the end face of the deflector 300. The side lip 524a shown by the dotted line is in the state. However, due to frictional resistance at the tip of the side lip 524 or the like, the tip of the side lip 524 may be turned up so as to bend inward in the radial direction without sliding on the end surface of the deflector 300.

Therefore, workability may be reduced, for example, the assembly work must be redone. Further, if the side lip 524 is not noticed that it has been turned over, the performance of the sealing device 500 is not sufficiently exhibited, so that the durable life of the sealing device 500 may be shortened.

In addition, in order to suppress the turning of the side lip 524, it is conceivable to adopt a configuration in which the tip of the side lip 524 expands more radially outward. However, if such a configuration is adopted, there is a drawback that the desired sealing property cannot be obtained because it slides with the deflector 300 near the root of the side lip 524 (see Patent Document 1). Therefore, it cannot be said to be the best measure.

International Publication No. 2017/51920

An object of the present invention is to provide a sealing device capable of suppressing the side lip from being turned over at the time of assembling.

The present invention employs the following means to solve the above problems.

That is, the sealing device of the present invention
A sealing device that seals an annular gap between a rotating shaft and a housing having a shaft hole through which the rotating shaft is inserted.
Reinforcing ring and
Elasticity having a seal lip integrally provided on the reinforcing ring and slidably provided with respect to the rotating shaft, and a side lip slidably provided on the end face of a rotating member rotating with the rotating shaft. Body-made sealing device body and
With
The side lip has an abdomen whose diameter increases as the fluid to be sealed is sealed from the sealed region side to the opposite side, and a tip portion provided on the tip side of the abdomen, and the abdomen is the tip portion. In addition to being configured so that the degree of diameter expansion is greater than
The outer peripheral surface of the side lip is characterized in that a plurality of protrusions provided so as to straddle the boundary portion between the abdomen and the tip portion are provided at intervals in the circumferential direction.

According to the present invention, a plurality of protrusions provided on the outer peripheral surface of the side lip so as to straddle the boundary portion between the abdomen and the tip portion of the side lip are provided at intervals in the circumferential direction. Therefore, even if the end face of the rotating member abuts against the tip of the side lip and a force that bends the tip inward in the radial direction acts on the side lip at the time of assembly, the resistance force is increased by the plurality of protrusions. work. As a result, it is possible to prevent the tip of the side lip from bending inward in the radial direction, and the side lip is deformed so as to bend outward in the radial direction while smoothly sliding on the end surface of the rotating member. Therefore, it is possible to prevent the side lip from being turned over.

As described above, according to the present invention, it is possible to prevent the side lip from being turned over at the time of assembling.

FIG. 1 is a schematic cross-sectional view of a sealing device according to an embodiment of the present invention. FIG. 2 is an explanatory view at the time of incorporating the sealing device according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the sealed structure according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of the sealing device according to the conventional example.

Hereinafter, embodiments for carrying out the present invention will be described in detail exemplarily based on examples with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention to those unless otherwise specified. ..

(Example)
The sealing device according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a schematic cross-sectional view of a sealing device according to an embodiment of the present invention. FIG. 2 is an explanatory view at the time of incorporating the sealing device according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the sealed structure according to the embodiment of the present invention. The sealing device according to the present embodiment has a rotationally symmetric shape except for a part of the configuration, and the sealing device in FIGS. 1 to 3 has a schematic cross section obtained by cutting the sealing device on a surface including the central axis. Is shown. In the following embodiment, the sealing device 100 provided in the differential mechanism in the differential device will be described as an example.

<Sealed structure>
In particular, with reference to FIG. 3, a sealing structure including the sealing device 100 according to the present embodiment will be described. The sealing structure according to this embodiment includes a rotating shaft 200, a housing 400 having a shaft hole through which the rotating shaft 200 is inserted, and a sealing device 100 that seals an annular gap between the rotating shaft 200 and the housing 400. Consists of. The rotating shaft 200 is provided with a deflector 300 as a rotating member that rotates together with the rotating shaft 200.

<Seal device>
In particular, the configuration of the sealing device 100 according to the present embodiment will be described with reference to FIGS. 1 and 3. The sealing device 100 according to the present embodiment includes a reinforcing ring 110 made of metal or the like, and an elastic sealing device main body 120 integrally provided with the reinforcing ring 110. The reinforcing ring 110 includes a cylindrical portion 111 and an inward flange portion 112 provided on one end side of the cylindrical portion 111.

The sealing device main body 120 is made of an elastomer material such as rubber. The sealing device main body 120 according to the present embodiment is provided on the outer peripheral surface side of the cylindrical portion 111 of the reinforcing ring 110, and has an outer peripheral sealing portion 121 fixed to the inner peripheral surface of the shaft hole of the housing 400 by fitting. I have. Further, the sealing device main body 120 is provided with a sealing lip that is slidably provided with respect to the rotating shaft 200. In this embodiment, as the seal lip, the main lip 122 for suppressing the leakage of the fluid to be sealed (oil, etc.) and the sealing area (on the right side in FIG. 3) in which the fluid to be sealed is sealed with foreign matter such as dust. A dust strip 123 is provided to prevent the region from invading the region.

The main lip 122 is configured to extend from the vicinity of the tip of the inward flange portion 112 of the reinforcing ring 110 toward the sealed region side. The main lip 122 according to this embodiment is provided with a plurality of screw protrusions 122a for returning the leaked fluid to be sealed to the sealing region. Further, in this embodiment, a garter spring 130 for pressing the lip tip of the main lip 122 against the surface of the rotating shaft 200 is mounted on the outer peripheral surface side of the main lip 122.

Further, the dust strip 123 is configured to extend from the vicinity of the tip of the inward flange portion 112 of the reinforcing ring 110 toward the atmospheric region (the region on the left side in FIG. 3) opposite to the sealing region. In this embodiment, a plurality of protrusions 123a are provided on the surface of the dust strip 123 in order to prevent the main lip 122 and the dust strip 123 from hitting the rotating shaft 200 in a solid manner. As a result, when the space between the main lip 122 and the dust strip 123 becomes a negative pressure state, a gap is formed in the vicinity of each protrusion 123a due to the deformation of the dust strip 123, and the gas enters the space. It flows in and the negative pressure state is eliminated.

Further, the sealing device main body 120 according to the present embodiment includes a side lip 124 slidably provided on the end surface of the deflector 300. The side lip 124 is provided to prevent dust, muddy water, and the like from entering the seal lip (main lip 122 and dust strip 123) side. Then, the side lip 124 has a root portion 124a, an abdomen 124b, and a tip portion 124c (a tip portion 124c provided on the tip side of the abdomen 124b) in order from the side closer to the reinforcing ring 110 to the side farther away. It is a configuration that is integrally provided with. The root portion 124a is composed of a substantially cylindrical portion. The abdomen 124b and the tip 124c are composed of tapered portions whose diameters increase from the sealed region side to the opposite side of the sealed fluid. Further, the abdomen 124b is configured so that the degree of diameter expansion is larger than that of the tip portion 124c (in a state where the sealing device 100 is not subjected to an external force), that is, the taper angle is larger (in a state where the sealing device 100 is not subjected to an external force). (See FIG. 1). In this embodiment, the configuration having a cylindrical portion (root portion 124a) is shown, but a configuration without a cylindrical portion can also be adopted. According to the side lip 124 configured as described above, since the tip portion 124c is configured to bend inward in the radial direction from the abdomen 124b, the rigidity can be increased. Therefore, it is possible to prevent the contact pressure from dropping even when the contact area becomes large when the inner peripheral surface of the tip of the side lip 124 is in contact with the deflector 300.

Then, on the outer peripheral surface of the side lip 124 according to the present embodiment, a plurality of protrusions 124d provided so as to straddle the boundary portion between the abdominal portion 124b and the tip portion 124c are provided at intervals in the circumferential direction. Note that FIG. 1 shows an enlarged view of a part of the outer peripheral surface of the side lip 124 in a circled portion. It is desirable that the plurality of protrusions 124d are provided at equal intervals. The number of protrusions 124d may be appropriately set depending on the dimensions of each part of the sealing device 100, the usage environment, and the like. Further, the dimensions of each protrusion 124d may be appropriately set depending on the number of protrusions 124d, the distance between the protrusions 124d, the usage environment, and the like. For example, the length in the axial direction is set to about 3 mm, the length in the width direction (circumferential direction) is set to about 1.5 mm, and the height (the height of protrusion from the surface on which the protrusion 124d is not provided) is set to about 0.5 mm. can do.

It is desirable to apply a lubricant such as grease to the sliding surfaces of the seal lip (main lip 122 and dust strip 123) and the side lip 124.

<Incorporation of sealing device>
In particular, the procedure for incorporating the sealing device 100 according to the present embodiment will be described with reference to FIG. The assembling work is performed so that the rotating shaft 200 is inserted relative to the sealing device 100 from the left side to the right side in the drawing (see the arrow in the drawing). In this process, the deflector 300 abuts on the tip of the side lip 124, and the rotation shaft 200 is further inserted, so that the tip of the side lip 124 slides with respect to the end face of the deflector 300 and flexes outward in the radial direction. nothing. As a result, the side lip 124 is in the state shown in FIG.

<Advantages of the sealing device according to this embodiment>
According to the sealing device 100 according to the present embodiment, protrusions 124d provided on the outer peripheral surface of the side lip 124 so as to straddle the boundary between the abdomen 124b and the tip 124c of the side lip 124 are spaced apart in the circumferential direction. There are multiple spaces. Therefore, even if the end surface of the deflector 300 as a rotating member abuts on the tip of the side lip 124 and a force is applied to the side lip 124 to bend the tip in the radial direction at the time of assembly, a plurality of of them. Resistance works by the protrusion 124d of. As a result, it is possible to prevent the tip of the side lip 124 from bending inward in the radial direction, and the side lip 124 is deformed so as to bend outward in the radial direction while smoothly sliding on the end face of the deflector 300. Therefore, it is possible to prevent the side lip 124 from being turned over.

Further, since a configuration in which a plurality of protrusions 124d are provided at intervals in the circumferential direction is adopted, it is possible to prevent the strength of the boundary portion between the abdominal portion 124b and the tip portion 124c from becoming too high. As a result, at the time of assembling, the tip of the side lip 124 does not hinder the behavior of being deformed so as to bend outward in the radial direction while sliding on the end surface of the deflector 300. In addition, it is possible to prevent the side lip 124 from increasing the sliding resistance of the deflector 300 with respect to the end surface.

(others)
In the above embodiment, the case where the sealing device is used for the differential mechanism has been described as an example. However, the present invention may also be applied to other uses. For example, the sealing device of the present invention can also be applied to devices such as hub bearings.

100 Sealing device 110 Reinforcing ring 111 Cylindrical part 112 Inward flange part 120 Sealing device main part 121 Outer peripheral sealing part 122 Main lip 122a Screw protrusion 123 Dustrip 123a Protrusion 124 Side lip 124a Root part 124b Abdomen 124c Tip part 124d Protrusion 130 Gata spring 200 Rotating shaft 300 Deflector 400 Housing

Claims (1)

A sealing device that seals an annular gap between a rotating shaft and a housing having a shaft hole through which the rotating shaft is inserted.
Reinforcing ring and
Elasticity having a seal lip integrally provided on the reinforcing ring and slidably provided with respect to the rotating shaft, and a side lip slidably provided on the end face of a rotating member rotating with the rotating shaft. Body-made sealing device body and
With
The side lip has an abdomen whose diameter increases as the fluid to be sealed is sealed from the sealed region side to the opposite side, and a tip portion provided on the tip side of the abdomen, and the abdomen is the tip portion. In addition to being configured so that the degree of diameter expansion is greater than
A sealing device characterized in that a plurality of protrusions provided on the outer peripheral surface of the side lip so as to straddle the boundary portion between the abdomen and the tip portion are provided at intervals in the circumferential direction.

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