JP3760327B2 - Sealing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sealing device used for a shaft seal portion of various hydraulic devices, and more particularly to a sealing device that seals a high-pressure fluid.
[0002]
[Prior art]
Conventionally, as this type of sealing device, there is an oil seal 101 as shown in FIG. The oil seal 101 is formed by integrally forming a covering portion 102 and a metal ring 103. In the oil seal 101, the truncated conical cylinder-shaped cage 104 and the seal lip portion 105 are configured to be non-bonded, and the cage 104 is in an unconstrained state in the radial direction.
[0003]
Under actual use conditions, mounting eccentricity, shaft eccentricity, and the like occur, and the seal lip 105 is pressed against the shaft by the pressure of the fluid to be sealed.
[0004]
[Problems to be solved by the invention]
FIG. 5 shows a state in which such shaft eccentricity has occurred. On the eccentric minus side (below the axis in FIG. 5), the cylinder lip 104a of the cage 104 (dashed line in FIG. 5) when not eccentric due to the fall of the seal lip 105 and the pressure acting on the seal lip 105. Excessive force acts on the. On the other hand, on the eccentric plus side (the upper side of the axis in FIG. 5), the seal lip portion 105 and the shaft 106 are deformed in a direction in which a gap is generated. The force acting on the cage 104 in the direction perpendicular to the axis is greater on the eccentric minus side than on the eccentric plus side. Therefore, actually, the cage 104 (solid line portion in FIG. 5) moves to the eccentric plus side and cannot be maintained at the intended position.
[0005]
As described above, since the cage 104 cannot perform the original function, the base portion 105a of the seal lip portion 105 is greatly deformed and the seal lip portion 105 is damaged due to the action of pressure (generally fluctuating pressure). The sealing performance is deteriorated due to a change in the contact state between the lip portion 105 and the sealing lip portion 105.
[0006]
In addition, the radial restriction of the cage 104 by the covering portion 102 on the outer diameter side of the flange portion 104a of the cage 104 is because the seal body is made of an elastic body such as rubber, and there is a sag due to deterioration of the rubber. It is not valid.
[0007]
In addition, when a high pressure is applied to the seal lip portion 105, the cage 104 is deflected 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 is reduced. .
[0008]
The present invention has been made to solve the problems of the prior art, and the object of the present invention is to stabilize the contact state between the shaft and the seal lip, to prevent damage to the seal lip and to improve the sealing performance. The goal is to improve.
[0009]
[Means for solving problems]
In order to achieve the above object, according to the present invention, there is provided a sealing device for sealing between a housing and a shaft assembled concentrically, the sealing device having a reinforcing ring assembled to the housing, and the reinforcing ring Is provided with a cylindrical portion assembled to the housing, a flange portion extending in the inner diameter direction from the end portion on the anti-sealing target fluid side of the cylindrical portion, and a support ring support portion extending from the inner diameter end portion of the flange portion toward the sealing target fluid side. A seal lip made of a rubber-like elastic body provided integrally with the reinforcing ring and in sealing contact with the shaft;
A cylinder portion extending toward the fluid to be sealed on the anti-sealing fluid side of the seal lip, and an inner diameter side end extending from the sealing fluid side end of the cylinder to the inner diameter side at right angles to the axis. The seal is mounted on the support ring support portion so as to be movable relative to the support ring support portion. The seal ring has a flat surface and includes an axial end portion of the support ring support portion and an inward flange portion having a gap. A support ring that supports the lip and an inner diameter side end provided on the support ring are formed on the inner diameter side of the seal lip on the side opposite to the fluid to be sealed, and the cylindrical portion of the support ring is formed on the reinforcing ring. The radial movement is restricted by fitting with the inner diameter portion, and 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.
[0010]
In this way, when eccentricity occurs between the two members assembled concentrically, the support ring and the reinforcement ring are fitted, and the radial movement of the support ring is restricted by the reinforcement ring. Therefore, 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 stabilized, and the sealing performance is improved. Further, it is possible to prevent the seal lip from being damaged due to the biting of the support ring into the seal lip.
[0011]
The second invention is characterized in that, in the first invention, an inner diameter side end portion provided in the support ring is formed on an inner diameter side of an anti-sealing target fluid side edge portion of the seal lip .
[0012]
If the inner diameter side end provided on the support ring is formed on the inner diameter side with respect to the anti-sealing target fluid side edge of the seal lip , a seal is formed when eccentricity occurs between two concentrically assembled members. Even if the lip and the support ring can move relative to each other, it is possible to prevent the seal lip from being damaged due to the biting of the support ring into the reel lip.
[0014]
As described above, by providing the reinforcing ring support portion that supports the anti-seal lip side 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 and the pressure of the fluid to be sealed is increased. The deformation of the support ring accompanying the deformation of the seal lip due to is suppressed, and the deformation of the seal lip becomes small. Therefore, the contact state between one member of the two members and the seal lip is stabilized, and the sealing performance is improved.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on the illustrated embodiments.
[0016]
(First embodiment)
FIG. 1 shows an oil seal 1 as a sealing device according to a first embodiment of the present invention.
[0017]
The oil seal 1 mainly includes a metal ring 3 having a substantially J-shaped cross section 3, a covering portion 2 made of a rubber-like elastic body, and an annular cage 4, and is concentrically assembled in the same manner as the oil seal 101 according to the prior art. The annular gap between the housing (not shown) and the shaft (not shown) is sealed.
[0018]
The metal ring 3 as the reinforcing ring is sealed from the cylindrical portion 31 extending in the axial direction, the flange portion 32 extending in the inner diameter direction from the anti-sealing target fluid side (A) end portion of the cylindrical portion 31, and the inner diameter side end portion of the flange portion 32. It consists of an inner diameter part 33 extending to the target fluid side (O).
[0019]
The covering portion 2 is formed integrally with the metal ring 3. Covering the inner and outer peripheral sides of the cylindrical portion 31 from the end of the sealing target fluid side (O) of the cylindrical portion 31 of the metal ring 3, and continuously sealing the flange portion 32 from the end of the anti-sealing target fluid side (A) 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 portion of the inner diameter portion 33 of the metal ring 3, and the inner diameter side end portion extends to the inner diameter direction anti-sealing target fluid side (A) and has a shaft. A dust lip 21 is provided for sliding and sealing (not shown). The sealing target fluid side (O) of the covering portion 2 covers the vicinity of the inner diameter side end of the flange portion 32 of the metal ring 3, and the inner diameter end extends to the inner diameter direction sealing target fluid side (O). A main seal lip portion 22 is provided as a seal lip that slides and seals on the shaft. On the inner diameter side of the base portion of the main seal lip portion 22, a recess 23 into which the cage 4 is fitted is formed. Further, an annular spring 5 for pressing the distal end portion 22a to the shaft side is attached to the groove 24 provided on the outer diameter side of the distal end portion 22a of the main seal lip portion 22.
[0020]
The retainer 4 as a support ring has a substantially S-shaped cross section, and extends from the axial direction toward the sealed fluid side (O) slightly in the inner diameter direction, and the sealed fluid side (O) of the tubular portion 41. The inward flange portion 42 extends from the end portion toward the inner diameter side, and the outward flange portion 43 extends in the outer diameter direction from the anti-sealing target fluid side (A) end portion of the cylindrical portion 41. The inner diameter portion 33 of the metal ring 3 is formed in the inner diameter direction slightly from the axial direction from the inner diameter side end portion of the flange portion 32 toward the fluid to be sealed (O), and is fitted to the cylindrical portion 41 of the cage 4. ing. The anti-sealing target fluid side (A) end surface 43 a of the outward flange portion 43 is in contact with the sealing target fluid side (O) end surface 32 a of the flange portion 32 of the metal ring 3. Thus, in this embodiment, the inner diameter part 33 and the flange part 32 of the metal ring 3 constitute a support ring support part that supports the cage as a support ring from the inner diameter side and the anti-sealing target fluid side (A). The cage 4 is mounted in a recess 23 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 covering portion 2, but the cage 4 and the covering portion 2 are not bonded. Relative movement is possible. Further, the inner diameter side end portion 42 a of the inward flange portion 42 of the cage 4 is located slightly on the inner diameter side with respect to the anti-sealing target fluid side (A) edge portion of the main seal lip portion 22. Thus, if the inner diameter side end portion 42a of the inward flange portion 42 of the cage 4 is formed slightly on the inner diameter side from the anti-sealing target fluid side (A) edge portion of the main seal lip portion, the main seal lip portion Therefore, the inner flange 22 is not damaged by the inner diameter side of the inward flange portion 42. The cage 4 and the metal ring 3 are not limited to being closely fitted, and may be fitted with a slight gap.
[0021]
In this way, by fitting the retainer 4 with the inner diameter portion 33 of the metal ring 3 whose outer diameter side is fixedly held by the housing via the covering portion 2 and whose radial movement is restricted, the retainer 4 is fitted. Since the movement in the radial direction is restricted, the contact state between the shaft and the main seal lip portion 22 does not become unstable even if mounting eccentricity, shaft eccentricity, or the like occurs. Therefore, it is possible to prevent damage to the main seal lip portion 22 and improve the sealing performance.
[0022]
Further, the anti-sealing target fluid side (A) and the inner diameter side of the cage 4 are supported by the flange portion 32 and the inner diameter portion 33 of the metal ring 3 to improve rigidity, and deformation of the cage due to the pressure of the fluid to be sealed is suppressed. Therefore, the deformation of the main seal lip portion 22 is reduced, and the contact state between the shaft and the main seal lip portion 22 is stabilized. Accordingly, the sealing performance is improved.
[0023]
(Second Embodiment)
FIG. 2 shows a second embodiment of the present invention.
[0024]
The oil seal 6 according to the present embodiment except for the shape of the cage 7, the shape of the inner diameter portion 34 of the metal ring 3, and the shape of the concave portion 25 on the inner diameter side of the base portion of the main seal lip portion 22 of the covering portion 2. Since it is the same as that of 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.
[0025]
The cage 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 sealing target fluid side (O) end of the cylindrical portion 71 toward the inner diameter side. The anti-sealing target fluid side (A) end surface 71 a of the cylindrical portion 71 is in contact with the sealing target fluid side (O) end surface 32 a of the metal ring 3. The cage 7 is fitted to the inner diameter portion 34 of the metal ring 3 formed in the axial direction so as to follow 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 constitute a support ring support portion that supports the cage 7 as a support ring from the inner diameter side and the anti-sealing target fluid side (A). The cage 7 and the metal ring 3 are not limited to being closely fitted, and may be fitted with a slight gap. The cage 7 is mounted in a recess 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 covering portion 2, but the cage 7 and the covering portion 2 are not bonded. The relative movement is possible. Further, the inner diameter side end 72 a of the inward flange portion 72 of the cage 7 is located slightly on the inner diameter side with respect to the anti-sealing target fluid side (A) edge of the main seal lip portion 22. Thus, if the inner diameter side end portion 72a of the inward flange portion 72 of the cage 7 is formed slightly on the inner diameter side with respect to the anti-sealing target fluid side (A) edge portion of the main seal lip portion 22, the main seal lip The portion 22 does not get caught and damaged by the inner diameter side of the inward flange portion 72.
[0026]
In this manner, the cage 7 is fitted by fitting the inner diameter portion 34 of the metal ring 3 whose outer diameter side is fixedly held in the housing via the covering portion 2 and whose movement in the radial direction is restricted, and the cage 7. Therefore, 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. Therefore, it is possible to prevent damage to the main seal lip portion 22 and improve the sealing performance.
[0027]
Further, the anti-sealing target fluid side (A) and the inner diameter side of the cage 7 are supported by the flange portion 32 and the inner diameter portion 34 of the metal ring 3 to improve rigidity, and deformation of the cage due to the pressure of the fluid to be sealed is suppressed. Therefore, the deformation of the main seal lip portion 22 is reduced, and the contact state between the shaft and the main seal lip portion 22 is stabilized. Accordingly, the sealing performance is improved.
[0032]
【The invention's effect】
According to the first invention, when the eccentricity occurs between the two members 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 possible, 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 the biting of the support ring into the seal lip.
[0033]
According to the second invention, the support ring and the reinforcement ring are fitted and the radial movement of the support ring is restricted, so that when an eccentricity occurs between two concentrically assembled members, Even if the lip and the support ring are 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 the biting of the support ring into the reel lip.
[Brief description of the drawings]
FIG. 1 is a cross-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 the structure of an oil seal according to a second embodiment of the present invention.
FIG. 3 is a half sectional view showing a configuration of an oil seal according to the prior art.
FIG. 4 is a diagram for explaining a problem of an oil seal according to the prior art.

Claims (1)

A sealing device that seals between a housing and a shaft that is concentrically assembled. The sealing device includes a reinforcing ring that is assembled to the housing, and the reinforcing ring includes a cylindrical portion that is assembled to the housing, and a reaction portion of the cylindrical portion. A flange portion extending in the inner diameter direction from the end portion on the fluid target side to be sealed, and a support ring support portion extending from the inner diameter end portion of the flange portion to the target fluid side to be sealed are provided. A seal lip made of a rubber-like elastic body provided integrally with the reinforcing ring and in sealing contact with the shaft; A cylinder portion extending toward the fluid to be sealed on the side opposite to the fluid to be sealed of the seal lip, and extending from the end on the fluid to be sealed side of the tube to the inner diameter side at right angles to the axis. The seal is mounted on the support ring support portion so as to be relatively movable between the support ring support portion and an inward flange portion having a gap. A support ring that supports the lip; The inner diameter side end provided in the support ring is formed on the inner diameter side of the anti-sealing target fluid side edge of the seal lip, The cylindrical portion of the support ring is engaged with the inner diameter portion of the reinforcing ring to restrict radial movement, and deformation of the support ring due to deformation of the seal lip due to the pressure of the fluid to be sealed is suppressed. A sealing device characterized by that.

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