JPH10325470A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize the contact state of a shaft with a seal lip and improve the damage prevention and seal performance of the seal lip by regulating the movement of a diameter direction foa support ring for supporting the seal lip by a reinforcement ring. SOLUTION: A holder 4 as a support ring with a nearly S letter shape section is composed of a cylinder part 41 extending to a little inner diameter direction toward a seal object fluid side O, an inward flange part 42 extending to the inner diameter side from the seal object fluid side O end of the cylinder part 41 and an outward flange part 43 extending to the outer diameter direction from the counter seal object fluid side A end of the cylinder part 41. The inner diameter part 33 of a metal ring 3 is formed to a little inner diameter direction from the inner diameter end part of a flange 32 toward the seal object fluid side O and fitted into the cylinder part 41 of the holder 4. Thus, by fitting the inner diameter part 33 of the metal ring 3 regulated the movement in the diameter direction with the holder 4, as the movement of the diameter direction of the holder 4 is regulated, the contact state of the shaft which a main seal lip 22 is not unstabilized, even if an installation eccentricity and a shaft eccentricity are generated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used for a shaft sealing portion of various hydraulic devices, and more particularly to a sealing device for sealing a high-pressure fluid.

[0002]

2. Description of the Related Art Conventionally, as this kind of sealing device, FIG.
There is an oil seal 101 as shown in FIG. The oil seal 101 is formed by integrally forming a coating portion 102 and a metal ring 103. In the oil seal 101, the truncated conical cylindrical retainer 104 and the seal lip portion 105 are configured to be non-adhered, and the retainer 104 is not restrained in the radial direction.

Under actual conditions of use, mounting eccentricity, shaft eccentricity, etc. occur, and the seal lip 105 is pressed against the shaft by the pressure of the fluid to be sealed.

[0004]

FIG. 5 shows a state in which such shaft eccentricity has occurred. On the eccentric minus side (the lower side of the axis line in FIG. 5), the cylinder end 104a of the retainer 104 (the broken line in FIG. 5) without eccentricity is formed by the falling of the seal lip 105 and the pressure acting on the seal lip 105. Excessive force acts on On the other hand, on the eccentric plus side (the upper side of the axis in FIG. 5), the seal lip 105 and the shaft 106 are deformed in a direction in which a gap is generated. The force acting on the retainer 104 in the direction perpendicular to the axis is larger on the eccentric minus side than on the eccentric plus side. Accordingly, in practice, the retainer 104 (solid line in FIG. 5) moves to the eccentricity plus side, and cannot be maintained at the expected position.

As described above, since the retainer 104 cannot perform its initial function, the base 1 of the seal lip 105
The deformation of 05a increases and the action of pressure (generally, fluctuating pressure) causes breakage of the seal lip portion 105 and lowers sealing performance due to a change in the contact state between the shaft 106 and the seal lip portion 105.

[0006] The radial restriction of the retainer 104 by the covering portion 102 on the outer diameter side of the flange portion 104a of the retainer 104 is such that the seal is made of an elastic material such as rubber, and the set due to deterioration of the rubber is reduced. It is not effective because it is.

Further, when a high pressure acts on the seal lip portion 105, the retainer 104 bends due to insufficient strength, so that the contact state between the shaft 106 and the seal lip portion 105 becomes unstable, and the sealing performance deteriorates. Is caused.

The present invention has been made to solve the problems of the prior art, and has as its object to stabilize a contact state between a shaft and a seal lip, to prevent breakage of the seal lip and to prevent the seal lip from being damaged. The purpose is to improve the sealing performance.

[0009]

According to a first aspect of the present invention, there is provided a sealing device for sealing between two members concentrically assembled, wherein one of the two members is sealed. A sealing lip made of a rubber-like elastic body, which is integrally formed with the reinforcing ring, and a supporting ring which is mounted on the opposite side of the sealing lip opposite to the fluid to be sealed and which supports the sealing lip. In the sealing device, the support ring may be restricted from moving in the radial direction by the reinforcing ring.

[0010] With this configuration, when eccentricity occurs between two members that are assembled concentrically, the radial movement of the support ring is restricted by the reinforcing ring, so that the seal lip and the support ring move relative to each other. Even if it is movable, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved. Further, it is possible to prevent the seal lip from being damaged due to, for example, biting of the support ring into the seal lip.

A second invention is characterized in that, in the first invention, the movement in the radial direction is restricted by fitting the support ring with the reinforcing ring.

If the support ring and the reinforcing ring are fitted to restrict the radial movement of the support ring, the concentrically assembled two
Even if the seal lip and the support ring can move relative to each other when eccentricity occurs between the members, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved.
In addition, it is possible to prevent the seal lip from being damaged due to, for example, biting of the support ring into the reel lip.

According to a third aspect of the present invention, in the first or second aspect, the reinforcing ring has a support ring supporting portion for supporting a side opposite to the seal lip of the support ring.

As described above, by providing the reinforcing ring supporting portion that supports the side opposite to the seal lip of the support ring, that is, the side that receives the deformation of the seal lip due to the pressure of the fluid to be sealed,
The rigidity of the support ring is improved, the deformation of the support ring due to the deformation of the seal lip due to the pressure of the fluid to be sealed is suppressed, and the deformation of the seal lip is reduced, so that the contact state between one of the two members and the seal lip. And the sealing performance is improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

(First Embodiment) FIG. 1 shows an oil seal 1 as a sealing device according to a first embodiment of the present invention.

The oil seal 1 mainly includes a metal ring 3 having a substantially J-shaped cross section, a covering portion 2 made of a rubber-like elastic body, and an annular retainer 4.
In the same manner as described above, the annular gap between the housing (not shown) and the shaft (not shown) which are assembled concentrically is sealed.

The metal ring 3 as a reinforcing ring includes a cylindrical portion 31 extending in the axial direction, a flange portion 32 extending in the radial direction from the end of the cylindrical portion 31 on the side of the fluid to be sealed (A), and a flange portion 32.
The inner diameter portion 33 extends from the inner diameter side end to the sealed fluid side (O).

The cover 2 is formed integrally with the metal ring 3. The inner and outer circumferences of the cylindrical portion 31 are covered from the fluid-side (O) end of the cylindrical portion 31 of the metal ring 3, and the flange 32 is continuously sealed from the fluid-side (A) end of the anti-sealing target. The fluid side (O) and the anti-sealing target fluid side (A) are covered to the inner diameter side. The anti-sealing target fluid side (A) of the covering portion 2 covers up to the base of the inner diameter portion 33 of the metal ring 3, and the end on the inner diameter side extends toward the anti-sealing target fluid side (A) in the inner diameter direction and has a shaft. (Not shown) is provided with a dust lip 21 for sliding sealing. The sealing target fluid side (O) of the covering portion 2 covers up to the vicinity of the inner diameter side end of the flange portion 32 of the metal ring 3, and the inner diameter side end extends toward the inner diameter direction sealing target fluid side (O). Main seal lip part 2 as seal lip for sliding sealing to shaft
2 are provided. A concave portion 23 into which the retainer 4 fits is formed on the inner diameter side of the base portion of the main seal lip portion 22. Also, the tip portion 22a of the main seal lip portion 22
An annular spring 5 for pressing the distal end portion 22a toward the shaft side is mounted in the groove 24 provided on the outer diameter side of the spring.

The retainer 4 serving as a support ring has a substantially S-shaped cross section, and has a cylindrical portion 41 extending slightly inward from the axial direction toward the fluid side (O) to be sealed, and the fluid side of the cylindrical portion 41 to be sealed. (O) Inward flange 4 extending from the end to the inner diameter side
2 and an outward flange 43 extending in the outer radial direction from the end (A) end of the cylinder 41 opposite to the fluid to be sealed. Metal ring 3
The inner diameter portion 33 is formed from the inner diameter side end of the flange portion 32 toward the fluid to be sealed (O) in a slightly inner diameter direction from the axial direction, and is fitted with the cylindrical portion 41 of the retainer 4. The end face 43 of the outward flange portion 43 on the side opposite to the fluid to be sealed (A)
“a” is in contact with an end surface 32 a of the flange portion 32 of the metal ring 3 on the fluid side (O) to be sealed. Thus, in the present embodiment, the inner diameter portion 33 and the flange portion 32 of the metal ring 3 are
A support ring supporting portion for supporting the retainer as a support ring from the inner diameter side and the side of the fluid to be sealed (A). Cage 4
Is a concave portion 2 on the inner diameter side of the base portion of the main seal lip portion 22.
3, the outer diameter side is covered with the covering portion 2, but the retainer 4 and the covering portion 2 are not bonded and can move relatively. Further, the inner diameter side end 42a of the inward flange portion 42 of the retainer 4 is located slightly inner diameter side than the edge of the main seal lip portion 22 on the side of the fluid to be sealed (A). If the inner end 42a of the inward flange 42 of the retainer 4 is formed slightly inner than the edge of the main seal lip opposite to the fluid to be sealed (A), the main seal lip is formed. There is no possibility that the recess 22 is caught in the inside of the inward flange portion 42 and is not damaged. The retainer 4 and the metal ring 3 are not limited to the case where they are closely fitted, and may be fitted with a slight gap.

As described above, by fitting the holder 4 to the inner diameter portion 33 of the metal ring 3 whose outer diameter side is fixed and held by the housing via the covering portion 2 and whose movement in the radial direction is restricted. Since the movement of the retainer in the radial direction is restricted, even if mounting eccentricity, shaft eccentricity, or the like occurs, the contact state between the shaft and the main seal lip portion 22 does not become unstable. Accordingly, it is possible to prevent breakage of the main seal lip portion 22 and improve sealing performance.

Further, the fluid side (A) of the cage 4 opposite to the fluid to be sealed.
And a flange portion 32 and an inner diameter portion 33 of the metal ring 3 on the inner diameter side.
And the deformation of the retainer due to the pressure of the fluid to be sealed is suppressed, so that the deformation of the main seal lip 22 is reduced, and the shaft and the main seal lip 22
The contact state with is stabilized. Therefore, the sealing performance is improved.

(Second Embodiment) FIG. 2 shows a second embodiment of the present invention.

The oil seal 6 according to the present embodiment includes the shape of the retainer 7, the shape of the inner diameter portion 34 of the metal ring 3, and the covering portion 2.
Concave portion 2 on the inner diameter side at the base of the main seal lip portion 22
Since it is the same as the first embodiment except for the shape of No. 5,
The same reference numerals are given and the description is omitted.

The retainer 7 of the oil seal 6 includes a cylindrical portion 71 extending in the axial direction, and an inward flange portion 72 extending from the end of the cylindrical portion 71 on the fluid side (O) to be sealed to the inside diameter.
The end surface 71a of the cylinder portion 71 on the side of the fluid to be sealed (A) is in contact with the end surface 32a of the metal ring 3 on the side of the fluid to be sealed (O).
The retainer 7 is fitted with the inner diameter portion 34 of the metal ring 3 formed in the axial direction along the cylindrical portion 34 on the inner diameter side. In the present embodiment, the inner diameter portion 34 and the flange portion 32 of the metal ring 3 are provided.
Constitute a support ring support portion that supports the retainer 7 as a support ring from the inner diameter side and the side of the fluid to be sealed (A). The retainer 7 and the metal ring 3 are not limited to being tightly fitted, but may be fitted with a slight gap. The retainer 7 is mounted in the concave portion 25 on the inner diameter side of the base portion of the main seal lip portion 22 and the outer diameter side is covered with the coating portion 2, but the retainer 7 and the coating portion 2 are not bonded. Are relatively movable. Further, the inward flange portion 7 of the cage 7
The inner diameter side end 72a of the second seal lip 22 is located slightly inner diameter than the edge of the main seal lip portion 22 on the side of the fluid to be sealed (A). In this way, if the inner diameter side end 72a of the inward flange 72 of the retainer 7 is formed slightly inner diameter than the edge (A) of the main seal lip 22 opposite to the fluid to be sealed (A), the main seal lip is formed. The portion 22 does not get caught in the inner diameter side of the inward flange portion 72 and is not damaged.

As described above, by fitting the retainer 7 to the inner diameter portion 34 of the metal ring 3 whose outer diameter side is fixed and held by the housing via the covering portion 2 and whose movement in the radial direction is restricted. Since the movement of the retainer 7 in the radial direction is restricted, even if mounting eccentricity, shaft eccentricity, or the like occurs, the contact state between the shaft and the main seal lip portion 22 does not become unstable. Accordingly, it is possible to prevent breakage of the main seal lip portion 22 and improve sealing performance.

Further, the fluid side (A) of the cage 7 opposite to the fluid to be sealed.
And a flange portion 32 and an inner diameter portion 34 of the metal ring 3 on the inner diameter side.
And the deformation of the retainer due to the pressure of the fluid to be sealed is suppressed, so that the deformation of the main seal lip 22 is reduced, and the shaft and the main seal lip 22
The contact state with is stabilized. Therefore, the sealing performance is improved.

(Third Embodiment) FIG. 3 shows a third embodiment of the present invention.

The oil seal 8 according to this embodiment is the same as the first embodiment except for the shape of the flange portion 35 of the metal ring 3, so that the same reference numerals are given and the description is omitted.

The flange 3 of the metal ring 3 of the oil seal 8
5 has an inner diameter portion 37 formed with a step portion 36 on the inner diameter side. The inner peripheral surface 36a of the step portion 36 and the outer diameter side end surface 42b of the outward flange portion 42 of the retainer 4 are fitted. The retainer 4 and the metal ring 3 are not limited to the case where they are closely fitted, and may be fitted with a slight gap.
The retainer 4 is mounted in the concave portion 23 on the inner diameter side of the base portion of the main seal lip portion 22 and the outer diameter side is covered by the covering portion 2, but the retainer 4 and the covering portion 2 are not bonded. Are relatively movable.

As described above, by fitting the step portion 36 of the metal ring 3 whose outer diameter side is fixed and held to the housing via the covering portion 2 and whose movement in the radial direction is restricted to the retainer 4, Since the movement of the retainer 4 in the radial direction is restricted, even if mounting eccentricity, shaft eccentricity, or the like occurs, the contact state between the shaft and the main seal lip portion 22 does not become unstable. Accordingly, it is possible to prevent breakage of the main seal lip portion 22 and improve sealing performance.

[0032]

According to the first aspect of the present invention, when eccentricity occurs between two members that are assembled concentrically, the radial movement of the support ring is restricted by the reinforcing ring, so that the seal lip and the support lip are supported. Even when the ring is relatively movable, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved. Further, it is possible to prevent the seal lip from being damaged due to, for example, biting of the support ring into the seal lip.

According to the second aspect, since the support ring and the reinforcing ring are fitted to each other and the movement of the support ring in the radial direction is restricted, when eccentricity occurs between the two members assembled concentrically. Even if the seal lip and the support ring are relatively movable, the contact state between one of the two members and the seal lip is stable,
The sealing performance is improved. In addition, it is possible to prevent the seal lip from being damaged due to, for example, biting of the support ring into the reel lip.

According to the third aspect of the present invention, the rigidity of the support ring is improved by providing the reinforcing ring support portion for supporting the side opposite to the seal lip of the support ring, that is, the side receiving the deformation of the seal lip due to the pressure of the fluid to be sealed. However, since the deformation of the support ring due to the deformation of the seal lip due to the pressure of the fluid to be sealed is suppressed and the deformation of the seal lip is reduced, the contact state between one of the two members and the seal lip is stabilized, and the sealing performance is improved. Is improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an oil seal according to a first embodiment of the present invention.

FIG. 2 is a half sectional view showing a structure of an oil seal according to a second embodiment of the present invention.

FIG. 3 is a half sectional view showing a structure of an oil seal according to a third embodiment of the present invention.

FIG. 4 is a half sectional view showing a configuration of an oil seal according to the related art.

FIG. 5 is a diagram for explaining a problem of the oil seal according to the related art.

[Explanation of symbols]

 1, 6, 8, 101 Oil seal 2, 102 Coating part 21 Dustrip part 22 Main seal lip part 3, 103 Metal ring 31 Tube part 32 Flange part 33, 34, 37 Inner part 4, 4, 7, 104 Cage 41 , 71 Tube part 42, 72 Inward flange part 43 Outward flange part

Claims (3)

[Claims] 1. A sealing device for sealing between two members assembled concentrically, wherein the sealing member is made of a rubber-like elastic body and formed integrally with a reinforcing ring, which sealingly contacts one of the two members. A sealing ring having a lip and a support ring mounted on the opposite side of the seal lip so as to be relatively movable to support the seal lip, wherein the support ring restricts radial movement by the reinforcing ring. Sealing device characterized by being done. 2. The sealing device according to claim 1, wherein the support ring is restricted from moving in the radial direction by fitting with the reinforcing ring. 3. The sealing device according to claim 1, wherein the reinforcing ring has a support ring supporting portion for supporting a side opposite to the seal lip of the support ring.