JPS6243178Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seal device, and more particularly to a seal installation for a fluid pressure cylinder or the like that prevents blow-through leakage.

Conventional sealing devices have relatively rotary and/or reciprocating motion as shown in FIG.
An annular mounting groove 3 with a substantially rectangular cross section is provided on the outer surface 2 of the shaft side member 1 made of steel, light alloy, etc., and a seal ring with a substantially rectangular cross section made of synthetic rubber, synthetic resin, etc. is provided in the mounting groove 3. 4 was installed.

Since the seal ring 4 made of a polymer material such as synthetic rubber or synthetic resin has a larger coefficient of linear expansion than the shaft side member 1 made of metal such as steel or light alloy, it In FIG. 2, the inner periphery 5 of the seal ring 4 and the bottom surface 6 of the mounting groove 3 are in close contact with each other. Further, there is a gap 10 between the outer periphery 7 of the seal ring 4 and the inner surface 9 of the mating hole side member 8 made of metal such as steel or light alloy.
occurs.

Therefore, when fluid pressure is applied from one side 11 of the sealing device in the above-mentioned state, fluid leaks from the gap 10 toward the other side 12. Moreover, since it is impossible for the fluid that has entered the mounting groove 3 to enter between the inner periphery 5 of the seal ring 4 and the bottom surface 6 of the mounting groove 3, the seal ring 4 cannot be moved into the hole side member 8. There is no effect of pressing against the inner surface 9 of the hole to stop the blow-through leakage. Therefore, there was a drawback that leakage could not be prevented.

The present invention eliminates the disadvantage of blow-through leakage at low temperatures of the conventional sealing device described above, and ensures that fluid pressure is applied between the inner circumferential surface of the seal ring and the bottom of the mounting groove even at low temperatures. The object of the present invention is to provide a sealing device that completely prevents blow-through leakage.

The purpose is to provide an annular mounting groove 3 with a substantially rectangular cross section provided on one of the opposing surfaces of two cylindrical members that rotate and/or reciprocate relative to each other.
and a seal ring 4 having a substantially rectangular cross section mounted in the mounting groove, the bottom surface 6 of the annular mounting groove 3 is provided with an annular groove adjacent to the groove side surface 15 on the side into which fluid pressure flows. This is achieved by providing the recess 13.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The sealing device of the present invention will be described below with reference to embodiments shown in the drawings.

In FIG. 3, a bottom surface 6 of a mounting groove 3 having a substantially rectangular cross section formed in an annular shape on the outer surface 2 of a shaft side member 1 made of steel or light alloy, etc., is adjacent to a groove side surface 15 on the side into which fluid pressure flows. Therefore, the axial width W is equal to the axial width G of the mounting groove 3 and the axial width T of the seal ring.
An annular recess 13 that is larger than the difference between the two and smaller than 1/2 of the axial width G of the mounting groove 3.
A seal ring 4 having a substantially rectangular cross section is mounted in the mounting groove 3.

When the temperature decreases, the inner periphery 5 of the seal ring 4 and the bottom surface 6 of the mounting groove 3 come into close contact with each other in FIG. 4, and the outer periphery 7 of the seal ring 4 is made of metal such as steel or light alloy. Mating hole side member 8
A gap 10 is created between the inner surface 9 and the inner surface 9.

Next, when fluid pressure is applied from one side 11 of the sealing device in the above state, the mounting groove 3
The fluid that has entered passes between the seal ring 4 and the side surface 15 of the annular mounting groove 3, enters the annular recess 13 provided in the bottom surface 6 of the mounting groove 3, and as shown in FIG. The outer periphery 7 of the hole side member 8 is pressed against the inner surface 9 of the hole side member 8 to prevent blow-through leakage. Therefore, blow-through leakage is completely prevented.

Incidentally, as shown in FIG. 6, when an annular recess 13 is provided on the bottom surface 6 of the mounting groove 3 and at the same time a notch 14 is provided at the corner of the edge of the mounting groove, blow-through leakage can be more quickly and completely prevented. It has the effect of

Further, the cross-sectional shape of the annular recessed portion 13 is not limited to the above embodiment, and may be formed into a polygon such as a quadrangle, a circle, etc., and the cross-sectional shape of the first notch 14 is also limited to the above embodiment. It may be formed into a rectangular shape, a circular shape, or the like.

Further, although the annular recess 13 is provided only on one side of the mounting groove bottom surface 6 in the embodiment, under conditions where fluid pressure is applied from both directions of the sealing device, the annular recess 13 is provided on both sides of the mounting groove bottom surface 6 in the axial direction. They may be provided close to each other.

As described above, in the sealing device of the present invention, the annular recess 13 is provided in the bottom surface 6 of the annularly formed mounting groove 3 having a substantially rectangular cross section, in close proximity to the groove side surface 15 on the side into which fluid pressure flows. In addition, since the seal ring 4 having a substantially rectangular cross section is mounted in the mounting groove 3, leakage from the blow-through can be completely prevented.

[Brief explanation of the drawing]

1 and 2 show a conventional example, and FIGS. 3 to 6 show embodiments of the present invention. FIG. 1 is a partial cross-sectional view, FIG. 2 is a partial cross-sectional view explaining the action of FIG. 1, FIG. 3 is a partial cross-sectional view, and FIGS. 4 and 5 are cross-sectional views explaining the action of FIG. 3. FIG. 6 is a partial cross-sectional view. DESCRIPTION OF SYMBOLS 1... Shaft side member, 3... Mounting groove, 4... Seal ring, 8... Hole side member, 13... Recess, 14...
...Notch, 15...Groove side surface on the pressure inflow side.

Claims (1)

[Claims for Utility Model Registration] (1) An annular mounting groove 3 with a substantially rectangular cross section provided on one of the opposing surfaces of two cylindrical members that rotate and/or reciprocate relative to each other; In a sealing device consisting of a seal ring 4 having a substantially rectangular cross section mounted in the mounting groove, an annular recess 13 is formed in the bottom surface 6 of the annular mounting groove 3 adjacent to the groove side surface 15 on the side into which fluid pressure flows. A sealing device comprising: (2) The axial width W of the annular recess 13 is
The axial width G of the seal ring and the axial width T of the seal ring
The sealing device according to claim 1, wherein the sealing device is larger than the difference between the width G of the mounting groove 3 and smaller than 1/2 of the axial width G of the mounting groove 3.