JP2519846Y2 - Sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a sealing device for sealing between a housing having a shaft hole and a shaft inserted in the shaft hole.

[Conventional technology]

Conventionally, as a sealing device for sealing between the housing of the reciprocating cylinder and the shaft, as shown in FIG.
The inner peripheral packing (25) that is airtightly fitted to the annular groove (24) formed on the outer peripheral surface of (3) and the outer peripheral surface that is airtightly fitted to the outer peripheral side of the packing (25). A piston (26) having an annular mounting groove (27) on the inside and the mounting groove (27) is mounted airtightly and slides airtightly against the inner wall of the shaft hole (22) of the cylinder (21). The outer packing (28),
A pair of annular spacers (31) arranged on both sides of the piston (26) in the axial direction, and a pair of axial spacers arranged outside the respective spacers (31) and fitted to the shaft (23). It is known to consist of a stop ring (32) and. The packing (28) on the outer peripheral side has a rectangular cross section and has a shaft hole (22).
And a back ring (30) that backs up the seal ring (29) from the inner peripheral side.

[Problems to be solved by the device]

As shown in FIG. 4, in the conventional sealing device described above, when the shaft (23) is eccentric in the radial direction, the packing (2
Since 8) comes into contact with the inner wall of the shaft hole (22) in an unstable state (so-called one-sided contact), there is a problem that a satisfactory sealing property cannot be ensured.

[Means for solving the problem]

In view of the above points, the present invention has been devised in order to solve the problems found in the above-mentioned prior art, and in order to achieve this object, a housing having a shaft hole and the shaft hole are inserted. In a sealing device for sealing between a shaft and a shaft, the shaft is airtightly fitted to the shaft, and the support ring is provided on the outer peripheral surface of the support ring, the support ring having an annular support surface having a concave spherical surface in cross section. The inner peripheral surface thereof is provided with an annular supported surface that has a convex spherical surface in cross section corresponding to the supporting surface and that slides airtightly with respect to the supporting surface, and an outer peripheral surface thereof is provided with an annular mounting groove. An annular piston provided with the packing, a packing airtightly mounted in the mounting groove and sliding airtightly with respect to the inner wall of the shaft hole, and a pair arranged on both sides in the axial direction of the support ring and the piston. Of spacers and the A stop ring of a pair of fitted to said shaft, to provide a more composed sealing device.

[Action]

A support ring fitted to the shaft and a piston carrying the packing are provided with a concave spherical support surface and a convex spherical supported surface which correspond to each other. Sliding to maintain stable contact of packing with shaft hole over the entire circumference.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, a support ring (6) made of a rubber-like elastic material is hermetically fitted in an annular groove (4) having an arcuate cross section formed on the peripheral surface of the shaft (3), and the support ring is formed. (6) An annular fitting surface (7) having a convex spherical surface in cross section corresponding to the groove bottom surface of the annular groove (4) is provided on an inner peripheral surface thereof, and an annular fitting surface having a concave spherical shape in cross section is provided on an outer peripheral surface thereof. And a ring-shaped step (9) at both ends in the axial direction. An annular piston (10) is arranged on the outer peripheral side of the support ring (6), and the piston (10) has an inner peripheral surface having a convex spherical surface in cross section corresponding to the support surface (8) and the support surface. An annular supported surface (11) that slides airtight against (8)
And an annular mounting groove (12) on the outer peripheral surface thereof. A packing (13) is mounted in the mounting groove (12), and the packing (13) has a rectangular cross section and is in surface contact with the inner wall of the shaft hole (2) of the housing (1). And a back ring (15) made of a rubber-like elastic material that backs up the seal ring (14) from the inner peripheral side. An annular metal spacer (16) is arranged on both sides of the support ring (6) and the piston (10) in the axial direction, and a metal stop ring (17) is provided on the outer side of each spacer (16) in the axial direction. Placed,
The stop ring (17) is fitted in an annular mounting groove (5) formed in the shaft (3).

When the shaft is eccentric, the sealing device having the above structure receives the eccentricity of the shaft (3) and tries to make one-sided contact with the inner wall of the shaft hole (2) of the housing (1) as shown in FIG. The movement of 13) is absorbed by the movement of the piston (10) with respect to the support ring (6), which is guided by the sliding movement of the support surface (8) and the supported surface (11), and the elastic deformation associated therewith. Therefore, as a result, the packing (13) does not move, the contact state of the packing (13) with the inner wall of the shaft hole (2) is stably maintained over the entire circumference, and excellent sealing performance is exhibited.

[Effect of device]

As described above, the sealing device of the present invention absorbs the movement of the packing when the shaft is eccentric by the movement of the piston relative to the support ring, which guides the sliding between the supporting surface and the supported surface, and the accompanying elastic deformation. Thus, the contact state of the packing with the inner wall of the shaft hole can be stabilized over the entire circumference, and the sealing performance can be improved.

[Brief description of drawings]

FIG. 1 is a half sectional view of a sealing device according to an embodiment of the present invention;
FIG. 2 is a half-cut sectional view when the shaft is eccentric, FIG. 3 is a half-cut sectional view of a sealing device according to a conventional example, and FIG. 4 is a half-cut sectional view when the shaft is eccentric. (1) …… Housing, (2) …… Shaft hole, (3) …… Shaft (4) …… Annular groove, (5) …… Mounting groove, (6) …… Support ring (7) …… Fitting Mounting surface, (8) …… Supporting surface, (9) …… Step (10) …… Piston, (11) …… Supported surface (12) …… Mounting groove, (13) …… Packing (14)… … Seal ring, (15) …… Back ring (16) …… Spacer, (17) …… Stop ring

Claims (1)

(57) [Scope of utility model registration request] 1. A sealing device for sealing between a housing (1) having a shaft hole (2) and a shaft (3) inserted through the shaft hole (2), wherein the shaft (3) is hermetically sealed. A support ring (6) fitted with an annular support surface (8) having a concave spherical surface in cross section, and an outer peripheral side of the support ring (6). An annular supported surface (11) having a convex spherical surface in cross section corresponding to the supporting surface (8) and sliding in an airtight manner with respect to the supporting surface (8) is provided, and an annular mounting groove is provided on the outer peripheral surface thereof. Annular piston (10) with (12)
And a packing (13) which is airtightly mounted in the mounting groove (12) and slides airtightly on the inner wall of the shaft hole (2).
A pair of spacers (16) arranged on both sides of the support ring (6) and the piston (10) in the axial direction, and an axially outer side of each of the spacers (16), and the shaft (3). A sealing device comprising a pair of stop rings (17) fitted to the above, and a stop ring (17).