JPS5851478Y2 - oil seal - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an oil seal.

To explain a conventional oil seal according to FIG. 1, an oil seal 4 press-fitted into a housing 2 includes an elastic member 10 having a sealing lip 8 for a shaft 6, and the elastic member 1.
It is formed from a metal holding member 12 that holds 0.

As shown in FIG. 1A, the outer peripheral surface of the oil seal 4 has a shape in which the holding member 12 is completely exposed and comes into contact with the housing 2, and as shown in FIG. 1B, the elastic member 10 is completely covered. There are two types: one in which the retaining member 12 and the elastic member 10 are exposed in half and in contact with the housing 2, as shown in FIG.

Although the oil seal 4 having the shape shown in FIG. 1A has high durability, it is difficult to work because it requires high pressure to press into the housing 2, and the sealing performance is incomplete. Moreover, if there are scratches on the outer peripheral surface, there are problems such as further deterioration of sealing performance.

The oil seal 4 having the shape shown in FIG. 1B has excellent workability because it requires a small press-fitting pressure, but it is likely to come off from the housing 2 due to elastic deterioration of the elastic member 10.

Although the oil seal 4 having the shape shown in FIG. It was difficult to press fit as it was often damaged.

The present invention has been proposed in view of the above, and is an oil seal comprising an annular holding member and an elastic member held by the holding member and having a sealing lip portion for a rotating wheel formed at the inner peripheral end. The outer circumferential surface of the holding member and the outer circumferential surface of the elastic member are formed substantially on the same plane to form the outer circumferential surface of the oil seal, and the outer circumferential surface of the holding member and the outer circumferential surface of the elastic member are both formed in a continuous portion. The oil seal is characterized in that at least one of its outer circumferential surfaces is formed into a barrel shape concave in the inner circumferential direction, and both of the outer circumferential surfaces are brought into contact with a housing, which improves sealing performance against the housing. The press-fitting process is easy, and the groove provided on the outer circumferential surface provides excellent effects such as preventing damage during press-fitting.

An embodiment of the present invention will be described below with reference to FIG.

Reference numeral 20 denotes an oil seal that is press-fitted into the housing 22, and the figure shows its shape before being press-fitted.

The oil seal 20 includes a metal annular holding member 24 and an elastic member 26 held by the holding member 24,
The elastic member 26 has a sealing lip portion 30 and an auxiliary lip portion 32 formed at its inner circumferential end with respect to the rotating shaft 28, and a coil spring 34 is disposed on the outer circumference of the sealing lip portion 30 to prevent rotation of the sealing lip portion 30. The pressure on the moving shaft 28 is set appropriately.

The outer diameter of the outer circumferential surface 36 of the holding member 24 is approximately the same as the inner diameter of the inner circumferential surface 38 of the housing 22, and the outer diameter of the outer circumferential surface 40 of the elastic member 26 is formed to be press-fitted with appropriate pressure. The outer diameter of the oil seal 20 is approximately the same as or slightly larger than that of the oil seal 20.
Forms the outer peripheral surface of.

42 is a groove formed in a continuous portion of the outer circumferential surface between the circumferential outer circumferential surfaces 36 and 40;
A second groove formed in the groove portion 44 and the outer circumferential surface 40 of the elastic member 21
The groove portion 46 is recessed in the inner periphery along the inner periphery direction.

The oil seal 20 having the above configuration is press-fitted into the inner circumferential surface 38 of the housing 22 and held at a predetermined pressure. Since the housing 2 is formed of
2 has the effect of being held on the inner circumferential surface 38.

Further, sealing performance is improved by elastic deformation of the outer circumferential surface 40 of the elastic member 26, and since the groove 42 is provided between the outer circumferential surface 36 of the holding member 24 and the outer circumferential surface 40 of the elastic member 26, oil This has the effect of allowing elastic deformation of the outer peripheral surface 40 of the elastic member 26 when the seal 20 is press-fitted, and effectively preventing damage, jamming, etc. during the press-fitting.

[Brief explanation of drawings]

FIGS. 1A, B, and C are explanatory views of a conventional oil seal, respectively, and FIG. 2 is a schematic explanatory view showing an embodiment of the present invention. 20 oil seal, 22: housing, 24: holding member, 26: elastic member, 28: shaft, 30: sealing lip part,
36, 40: outer peripheral surface, 42: groove.

Claims (1)

[Scope of utility model registration request] In an oil seal that is press-fitted into a housing and includes an annular holding member and an elastic member that is held by the holding member and has a sealing lip against a rotating shaft formed at the inner peripheral end, the outer peripheral surface of the holding member and The outer circumferential surface of the elastic member is formed substantially on the same plane as the outer circumferential surface of the oil seal, and at least two of the outer circumferential surfaces are formed at the connecting portion between the outer circumferential surface of the holding member and the outer circumferential surface of the elastic member. An oil seal characterized in that it is formed in a groove shape concave in the inner circumferential direction, and both of the outer circumferential surfaces are brought into contact with a housing.