JP2592489Y2 - Reciprocating sealing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating sealing device such as an oil seal used for a shaft sealing portion of various devices, and more particularly to a device having a groove on a sealing sliding surface thereof.

[0002]

2. Description of the Related Art As a conventional sealing device of this kind, for example, there is one as shown in FIG. That is, the reciprocating sealing device 100 seals an annular gap between the housing 101 and the reciprocating shaft 102 as two members which are assembled concentrically and are provided so as to be relatively reciprocable. This fluid does not leak to the atmosphere side A, and has an annular seal body 103 attached to the housing 101.

[0003] The seal main body 103 includes a reciprocating shaft 102.
Is provided with a seal lip 104 in sealing contact with the outer peripheral surface of the seal lip 104. A plurality of grooves 106 for reducing frictional force are provided in parallel on a sealing sliding surface 105 of the seal lip 104.

The shape of the groove 106 is shown in FIGS.
As shown in (d), there are trapezoidal grooves (FIG. (B)), right-angle grooves (FIG. (C)), and semicircular grooves (FIG. (D)).

[0005]

However, in the case of the above-mentioned prior art, there is no angle difference between the sealed fluid side O and the atmosphere side A in the shape of the groove 106, and the shapes are almost the same. There is a disadvantage that the flow of the fluid interposed between the groove 106 and the reciprocating shaft 102 tends to be unstable, and the sealing property is unstable.

Therefore, in order to stabilize the flow by regulating the flow of the fluid, a groove 1 is formed in the sealing sliding surface 105.
6, parallel projections 107 are provided on the sealing sliding surface 105 as shown in FIG.
There is provided a difference in the angle theta ₂ of one axial side of the slope 107A of the angle theta ₁ and the other side of the slope 107B (see JP-real-Open No. 5-27430) is, the sealing lip 104 by parallel projection 107 The surface pressure of the seal is likely to be unstable because the tip of the seal is lifted. In addition, since the projections are used, the angles θ ₁ and θ ₂ may fluctuate during operation, which may prevent the flow of the fluid from being maintained.

The present invention has been made to solve the above-mentioned problems of the prior art, and aims at stabilizing the sealing performance by stabilizing the flow of a fluid on a sealing sliding surface. An object of the present invention is to provide a reciprocating sealing device capable of improving the sealing performance by keeping the sealing surface pressure constant.

[0008]

In order to achieve the above object, according to the present invention, an annular gap between two members which are assembled concentrically and are relatively reciprocally movable is sealed. An annular seal body is attached to one of the two members, and a rubber bullet is slidably abutted on the seal body with the other member of the two members.
In a sealing device for reciprocating movement provided with a sealing sliding member made of a body, the sealing sliding member has a tip end in a cross section in the axial direction.
Has a wedge-shaped seal lip, and the tip of the seal lip
A plurality of annular grooves with a predetermined width are formed on the slope on one side in the axial direction of the
Comprising a sealing sliding surface having through surface portion, said plurality of annular
Angle of the slope on one side in the axial direction in the groove of the other side
Characterized by being provided smaller than the angle of the slope .

[0009]

In the sealing device having the above-described structure, the angle of the slope on one axial side of the groove provided on the sealing sliding surface is set to the angle of the slope on the other side.
Since the angle is smaller than the angle , the direction of the flow of the fluid is generated on the sealed sliding surface during operation, and the flow is stabilized.

Further, since the groove is provided on the sealing sliding surface, the lip tip of the sealing lip is always in contact, so that the sealing surface pressure can be kept constant and the sealing property is improved.

Further, since a flat portion having a predetermined width is provided between the grooves, the angle of the slope in each groove is stabilized even during operation, so that the angle difference can be maintained and the directionality of the fluid flow is maintained. be able to.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1 showing a reciprocating sealing device according to an embodiment of the present invention, reference numeral 1 denotes a reciprocating sealing device, and the reciprocating sealing devices 1 are assembled concentrically with each other and are relatively reciprocally movable. An annular gap between the housing 2 as a two-member member and the reciprocating shaft 3 is sealed so that the fluid on the sealed fluid side O does not leak to the atmosphere side A. And an annular seal body 4.

The seal body 4 has a substantially inverted h-shaped cross section.
A reinforcement ring 5 having an L-shaped cross section is provided. The reinforcing ring 5 is a cylindrical member having a flange portion 51 extending inward in the radial direction. A main seal lip 6 and a sub seal lip 7 made of a rubber-like elastic material are integrally printed on the inner end of the flange portion 51. Fixed. A rubber-like elastic body 8 is integrally fixed to the outer periphery of the cylindrical portion 52 of the reinforcing ring 5 by baking.
The rubber-like elastic body 8 is a fitting and fixing portion to be fitted to the inner peripheral surface of the housing 2.

The main seal lip 6 extends from the inner end of the flange portion 51 of the reinforcing ring 5 to the sealed fluid side O in the axial direction, and has a stepped seal composed of a first lip 61 and a second lip 62. It is a lip. These first and second lips 6
Numerals 1 and 62 have a wedge-shaped cross section, and each lip tip slidably and sealingly contacts the outer peripheral surface of the reciprocating shaft 3, and each slope on the atmosphere side A forms a sealing sliding surface 63, 64. A plurality of annular grooves 9 are provided on the sealing sliding surfaces 63 and 64 in parallel.

The groove 9 has a substantially trapezoidal cross section, and a reciprocating shaft includes a sealed fluid side tapered surface 91 as one axially inclined surface and an atmosphere side tapered surface 92 as the other inclined surface in the groove 9. In order to provide a difference in the pressure gradient on FIG.
As shown in (c), the angle α between the one axial end of the so-called upper base 93 and the tapered surface 91 on the sealed fluid side in the groove 9 is set to 45 ° in the present embodiment, whereas the axis of the upper base 93 is set. In this embodiment, the angle β between the other end in the direction and the atmosphere-side tapered surface 92 is set to 10 ° or less to provide an angle difference.
A straight portion 94 as a flat portion having a predetermined width is provided between the grooves 9, and the length 1 is set to 0.15 mm in this embodiment. Also, the depth t of the groove 9
Is set to 0.05 mm in this embodiment. Although the angle β is set to 10 ° or less, this is due to workability, and 0 ° is most desirable from the viewpoint of sealability.

On the outer periphery of the main seal lip 6,
A main coil spring 10 for applying a tightening force to the reciprocating shaft 3 is mounted.

On the other hand, the auxiliary seal lip 7 is for preventing dust and the like from entering from the atmosphere side A, and extends from the inner end of the flange portion 51 of the reinforcing ring 5 toward the atmosphere side A in the axial direction. , And is slightly smaller than the main seal lip 6. The lip tip 71 of the sub-seal lip 7 has a wedge-shaped cross-section, and comes into slidable sealing contact with the outer peripheral surface of the reciprocating shaft 3. A sub coil spring 11 smaller than the main coil spring 10 is also mounted on the outer periphery of the sub seal lip 7.

In the reciprocating sealing device having the above structure,
When the reciprocating shaft 3 reciprocates, the first and second seal lips 6
The respective sealing sliding surfaces 63, 6 of the second lips 61, 62
Since the sealing fluid is interposed between the groove 9 provided in the reciprocating shaft 3 and the outer periphery of the reciprocating shaft 3, the width of contact between the outer peripheral surface of the reciprocating shaft 3 and the sealing sliding surfaces 63 and 64 is small. Thus, the frictional force between the reciprocating shaft 3 and the outer peripheral surface is reduced.

The angle α of the tapered surface 91 on the sealed fluid side and the angle β of the tapered surface 92 on the atmosphere side in the groove 9 provided on the sealing sliding surfaces 63, 64 of the first and second lips 61, 62. , A difference is generated in the pressure gradient on the reciprocating shaft 3, the direction of the flow of the sealed fluid is generated, and the flow of the sealed fluid is stabilized. In addition, the sealing performance can be stabilized.

Since the straight portions 94 are provided between the grooves 9, the set values of the angles α and β can be satisfactorily stabilized even during operation, so that the angle difference is maintained. Since the direction of the flow of the sealed fluid can be maintained, the sealing performance is more stable.

Further, since the groove 9 is provided on the sealing sliding surfaces 63, 64, the respective lip tips of the first and second lips 61, 62 are not lifted by the parallel projections as in the prior art. Because it is always in contact,
The sealing surface pressure can be kept constant, and the sealing performance is improved.

As described above, since the sealing property is stabilized, the durability is improved and the quality can be improved.

FIG. 2 shows a second embodiment of the present invention. In the present embodiment, the seal body 4 is provided with a main seal lip 6 having substantially the same configuration as that of the first embodiment and an auxiliary seal lip 7A having a rectangular cross section at the inner end of a reinforcing ring 5A having a rectangular cross section. is there. For other configurations and actions, refer to
Since the configuration is the same as that of the embodiment, the same components are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 3 shows a third embodiment of the present invention. In this embodiment, a seal lip 12 having a wedge-shaped cross section is provided on the inner peripheral side of the seal body 4, and a groove 9 and a straight portion 94 having the same configuration as those in the above embodiments are provided on a sealing sliding surface 13A of the lip tip 13. And seal lip 1
2 is provided with a backup ring 14 on the inner periphery. Other configurations and operations are the same as those of the above-described embodiments, and therefore, the same components are denoted by the same reference numerals and description thereof will be omitted.

It should be noted that the set values of the angles and dimensions of the groove 9 and the straight portion 94 shown in each of the above embodiments are not limited to the above set values, but may be appropriately determined according to the specifications and the like. Also, the shape of the groove is not limited to a substantially trapezoidal cross-sectional shape, but may be a triangular cross-sectional shape or a semicircular cross-sectional shape.

[0026]

[Effect of the Invention] The present invention has the above-described structure and operation. The angle of the inclined surface on one side in the axial direction is different from that of the sealing sliding surface.
Since the groove provided is smaller than the angle of the slope on the side , the direction of flow of the fluid is generated on the sealing sliding surface during operation, and the flow is stabilized, so that the sealing performance is stabilized.

Also, since the groove is provided on the sealing sliding surface, the lip tip of the seal lip is always in contact, so that the sealing surface pressure can be kept constant and the sealing property is improved. Furthermore, since a flat portion having a predetermined width is provided between the grooves, the angle of the slope in each groove is stabilized even during operation, so that the angle difference can be maintained, and the fluid flow directionality can be maintained. . Therefore, the sealing performance is more stable.

[Brief description of the drawings]

FIG. 1 (a) is a longitudinal sectional view of a reciprocating sealing device according to an embodiment of the present invention, and FIG. 1 (b) is an enlarged sectional view of a main part of a main seal lip of FIG. 1 (a). FIG. 3C is an enlarged sectional view of a main part showing the groove of FIG.

FIG. 2 is a longitudinal sectional view of a reciprocating sealing device according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a reciprocating sealing device according to a third embodiment of the present invention.

FIG. 4 (a) is a longitudinal sectional view of a main part of a conventional sealing device for reciprocating motion, and FIGS. 4 (b) to 4 (d) show the groove shape of FIG. 4 (a); FIG. 4B shows a trapezoidal groove, FIG. 4C shows a right-angle groove, and FIG. 5D shows a semicircular groove.

FIG. 5 is a longitudinal sectional view of a main part showing parallel projections of another conventional sealing device for reciprocating motion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reciprocating sealing device 2 Housing 3 Reciprocating shaft 4 Seal body 5, 5A Reinforcement ring 51 Flange part 52 Cylindrical part 6 Main seal lip 61 First lip 62 Second lip 63, 64 Sealing sliding surface 7, 7A Secondary seal lip 71 Lip tip 8 Rubber-like elastic body 9 Groove 91 Sealed fluid side tapered surface (slope) 92 Atmospheric side taper surface (slope) 93 Top bottom 94 Straight portion (flat portion) 10 Main coil spring 11 Sub coil spring 12 Seal lip 13 Lip Tip 13A Sealed sliding surface 14 Backup ring

Claims (1)

(57) [Scope of request for utility model registration] 1. A seal for sealing an annular gap between two members which are assembled concentrically and are relatively reciprocally movable, and an annular seal body is mounted on one of the two members. At the same time, the seal body is made of a rubber-like elastic body that slidably abuts on the other of the two members .
In a reciprocating sealing device provided with a sealing sliding member , the sealing sliding member has a wedge at a tip end in a cross section in an axial direction.
Shape of the seal lip,
A plurality of annular grooves are formed on the slope on one side in the axial direction.
And a slope on one side in the axial direction in the plurality of annular grooves.
Wherein the angle is smaller than the angle of the slope on the other side .