JPH0225977Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to an oil seal used for gas sealing, and particularly when removed from a housing.
The purpose is to facilitate the removal work.

[Conventional technology]

Conventionally, as an oil seal, as shown in Fig. 5, airtightness is maintained between the inner diameter flanges a' and b' of an outer ring a and an inner ring b fitted on its inner periphery by a gasket c. It has a structure in which the outer diameter part of the seal lip d is held between
There is one in which a snap spring h is used to prevent the shaft from coming off to the atmosphere A, and the inner diameter end of the seal lip d is brought into sliding contact with the outer peripheral surface of the shaft e for shaft sealing.

[Problem that the invention attempts to solve]

When replacing the oil seal with the above configuration, remove the snap spring h, remove the housing f from the equipment body, and push out the outer ring a in the direction of arrow The oil seal is pulled out by hooking it from the atmosphere A side with a suitable jig, but the former method requires a lot of effort to remove the oil seal, and the latter method requires a large amount of force to attach the oil seal to the housing f. If it is large, the inner diameter flange a' of the outer ring a or the hooking part of the jig may be deformed, making it impossible to remove it.

[Means for solving problems]

Therefore, in order to solve the above problem, the oil seal of the present invention has an engaging protrusion that extends in the axial direction and is formed by punching out or cutting up toward the inner diameter on the atmospheric side end of the outer ring. A gap is formed on the inside in the axial direction.

[Effect]

When removing the oil seal from the inner circumference of the housing, use a removal jig with an appropriate hook protruding from it, and attach the hook to the atmosphere-side end of the outer ring. All you have to do is insert it into the gap on the inside of the formed engagement protrusion (on the seal lip side), engage it with the engagement protrusion in the axial direction, and then pull it strongly.At this time, since the engagement protrusion has a structure that extends in the axial direction, , it is difficult to deform due to resistance during pulling out, and can be pulled out reliably.

〔Example〕

Hereinafter, the oil seal of the present invention will be explained with reference to the illustrated embodiments.

First, the oil seal of the first embodiment shown in FIGS. 1 and 2 has a pair of axially extending cylindrical surfaces punched out toward the inner diameter side at 180-degree symmetrical positions on the end facing the atmosphere A. On the inner periphery of the outer ring 1 having the engaging protrusions 2a, 2a, in order from the engaging protrusion 2a side, an inner ring 3 having an L-shaped cross section, an annular gasket 5, an outer diameter part of the seal lip 6, and another ring having an L-shaped cross section. One inner ring 4 is inserted therein, and the end portion 1a of the outer ring 1 facing the sealing liquid B is bent radially inward to form an integrally caulked structure.

That is, the outer diameter portion of the seal lip 6 is fixed to the inner circumference of the outer ring 1 while being airtightly sandwiched between the inner diameter flanges 3a and 4a of the inner rings 3 and 4 facing each other in the axial direction via the gasket 5. and the engaging protrusions 2a, 2
a and the inner diameter flange 3a of the inner ring 3 located on the inside in the axial direction.
There is a gap 7 between them.

This oil seal is press-fitted from the atmosphere A side into the inner periphery of a housing 8 having a stepped portion 8a whose inner diameter is larger on the atmosphere A side, and the sealing liquid side end 1a of the outer ring 1 is inserted into the stepped portion 8a. 8a through the O-ring 9, and the sealing fluid B The shaft 1 is inserted into the housing 8 at the inner diameter end of the seal lip 6 which curves and protrudes to the side.
It slides into contact with the outer circumferential surface of 1 and performs a shaft sealing function.

When removing the oil seal from the above-mentioned installed state, for example, a cylindrical removal jig 12 as shown in FIG. 3 is used. This removal jig 12 is attached to the tip of a cylindrical rod portion 13 that can be inserted onto the shaft 11.
Engagement projections 2a, 2a of the outer ring 1 of the oil seal
In other words, after the snap spring 10 is removed from the inner periphery of the housing 8, the removal jig 12 is attached to the flanged hook portion. 15
With the side first, insert it onto the shaft 11 from the atmosphere A side, and adjust the positions of the notches 14, 14 to the engagement protrusions 2a, 2a.
Move the flanged hook part 15 to the axially inner position of the engaging protrusion 2a, and turn the cylindrical rod part 13 to axially align the flanged hook part 15 to the engaging protrusion 2a, 2a. After the oil seal is engaged in the direction, the jig 12 is pulled out to take out the oil seal from the inner periphery of the housing 8. At this time, since the engaging protrusions 2a, 2a have a structure extending in the axial direction, the flanged hook portion 15 of the removal jig 12
It does not easily deform due to loads from
Moreover, the large hook part 15 as shown in Fig. 3 above
Since the removal jig 12 can be used, even if the fitting force of the oil seal to the housing 8 is large, the oil seal can be removed reliably.

Next, a second embodiment shown in FIG. 4 has a cylindrical engagement protrusion 2a,
2a, the end of the outer ring 1 facing the atmosphere A
It has engaging protrusions 2b, 2b, each consisting of two cut-and-raised pieces extending in the axial direction, which are cut and raised toward the inner diameter side at 180-degree symmetrical positions. The procedure and its effects are the same as above.

[Effect of idea]

As described above, since the oil seal of the present invention has a structure in which the engaging protrusion formed on the end of the outer ring on the atmosphere side extends in the axial direction, deformation due to resistance during pull-out is less likely to occur. Since a jig having a hanging portion can be used, an excellent effect is achieved in that even if the fitting force of the oil seal to the housing is large, it is possible to reliably extract the oil seal.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view of the installed state of the oil seal showing the first embodiment of the present invention, Fig. 2 is a left side view, Fig. 3 is a perspective view of the removal jig, and Fig. 4 is the second embodiment. FIG. 5 is a left side view of an example oil seal, and FIG. 5 is a half-cut cross-sectional view of the conventional structure of the oil seal in an installed state. 1 Outer ring, 2a, 2a engagement protrusion, 6 seal lip, 7 gap, 8 housing, 11 shaft, 12
Removal jig.

Claims (1)

[Scope of utility model registration request] On the inner periphery of the outer ring that is hermetically inserted into the housing,
An oil seal carrying a seal lip that closely slides on the outer circumferential surface of the shaft, the outer ring having an engagement protrusion extending in the axial direction formed by punching out or cutting up toward the inner diameter at the end of the outer ring on the atmosphere side; An oil seal characterized in that a gap is formed inside the engagement protrusion in the axial direction.