JPH0215080Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a lip seal that seals around the rotating shaft of various devices such as car coolers.

[Conventional technology]

Conventionally, lip seals such as those shown in FIG. 2, for example, have been known.

This lip seal is attached to the inner periphery of metal case a.
A gasket b and a lip member c made of an elastic material are fitted, and the gasket b and lip member c are sandwiched between an inner diameter flange portion a' of the case a and a retainer d fitted to the inner periphery of the case a. This is what I did.

This lip seal is attached to the inner circumferential surface of the large diameter side of the inner circumferential stepped portion i of the device housing e in the case a.
e' through a packing h such as an O-ring held in the circumferential groove g of the inner circumferential surface e', and the stepped portion i and the large diameter inner circumferential surface e' A lip member c fixed between the metal snap ring j fitted into the lip member c and extending bent toward the sealed space A side.
The inner diameter end c' of the housing e is in sliding contact with the outer circumferential surface of the shaft f inserted into the housing e, and prevents the sealing fluid from leaking from the sealed space A.

[Problem that the invention attempts to solve]

However, since the lip seal described above has a circumferential groove g for holding the packing h provided on the inner circumferential surface e' of the housing e, it is difficult to process the circumferential groove g, especially with high precision. Ta.

Therefore, it is conceivable to provide the circumferential groove g on the case a side, but in this case, when attaching the packing h to the circumferential groove g, it is necessary to widen the inner diameter of the packing h to the outer diameter of the housing e, and As a result, there was a risk that the packing h would be damaged.

[Means for solving problems]

In order to solve the above problems, the lip seal of the present invention has an annular recess with an L-shaped cross section that is open toward the inner circumferential step of the housing and the inner circumferential surface of the large diameter side of the step at one end of the metal case. A packing is attached to the annular recess, and a flange portion extending radially inward from the open axial end of the annular recess and facing the step portion is bent.

[Effect]

According to the present invention, an annular recess into which a packing for maintaining airtightness between the housing and the metal case is attached is formed at one end of the metal case in a shape that opens in the axial direction toward the stepped portion of the housing. Therefore, when installing the packing, there is no need to expand the inner diameter of the packing to the outer diameter of the metal case, and the flange portion is bent from the open axial end of the annular recess toward the inner diameter side. Because of this, the packing can be smoothly inserted into the annular recess without biting the end. Further, the flange portion positions the lip seal by coming into contact with the step portion, and an appropriate compression in the axial direction of the packing can be set depending on the position where the lip seal extends from the annular recess.

〔Example〕

Hereinafter, the specific structure of the lip seal according to the present invention will be explained with reference to an embodiment shown in FIG.

That is, in the lip seal of this example,
1 is an O-ring 7 as a packing on the large-diameter inner circumferential surface 8a of the housing 8 in which the inner circumferential stepped portion 9 is formed.
This is a metal case that is fitted through a metal case 1 and fixed with a snap spring 10 to prevent it from coming off.The end of the case 1 on the inner circumferential stepped portion 9 side has the inner circumferential stepped portion 9 and the large diameter side inner circumferential surface 8a. An annular recess 2 with an L-shaped cross section for attaching and holding the O-ring 7; A flange portion 3 is formed, the portion of which faces the stepped portion 9 in the axial direction.

A gasket 4 and a lip member 5 whose inner diameter end 5a closely slides on the outer peripheral surface of the shaft 11 are fitted into the inner periphery of the metal case 1. The retainer 6 is crimped and held between the radial wall surface 2b of the recess 2 and a retainer 6 fitted to the inner periphery of the metal case 1 at an end opposite to the inner circumferential stepped portion 9.

According to the above configuration, when the O-ring 7 is press-fitted into the outer periphery of the annular recess 2 from the open end 2a side of the annular recess 2 provided in the case 1, the outer surface of the end 2a forms an R shape due to bending. Therefore, the O-ring 7 is not damaged by galling. Further, the flange portion 3 positions the lip seal in the axial direction by coming into contact with the inner circumferential stepped portion 9 of the housing 8. The crushing margin in the axial direction can be set appropriately.

[Effect of idea]

As described above, according to the present invention, the annular recess that holds the packing interposed between the housing and the metal case is provided at one end of the metal case in a shape that is open in the axial direction, and is bent from the open end. Since the flange portion extending toward the inner diameter side is provided, the packing can be easily attached to the outer periphery of the annular recess without expanding the packing to the outer diameter of the case.Moreover, at that time, since the packing does not get caught on the edge of the case, the packing damage can be prevented. Furthermore, the flange has an excellent effect in that appropriate compression in the axial direction of the packing can be set depending on the position where it extends from the annular recess.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view showing an embodiment of the lip seal of the present invention in a used state, and FIG. 2 is a half-cut sectional view showing an example of a conventional structure in a used state. DESCRIPTION OF SYMBOLS 1... Case, 2... Annular recess, 2a... Open end, 3... Flange, 5... Lip member, 7... O-ring (packing), 8... Housing, 9... Inside Circumference step part, 11...shaft.

Claims (1)

[Scope of utility model registration request] A lip seal consisting of a lip member whose inner diameter end slides closely against the shaft outer circumferential surface on the inner circumference of an annular metal case that is fitted to the large diameter inner circumferential surface of the inner circumferential stepped portion of the housing via packing. In,
An annular recess with an L-shaped cross section that is open toward the inner circumferential stepped portion of the housing and the inner circumferential surface of the larger diameter side of the stepped portion is formed at one end of the case, and the packing is mounted in the annular recessed portion. A lip seal characterized in that a flange portion extending from the open axial end of the annular recess toward the inner diameter side and facing the step portion is bent.