JP2000009235A - Oil seal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil seal that holds improved adhesion of a lubricative resin layer to its seal lip part and thus avoids peeling of the lubricative resin layer to the utmost even when used under severe conditions. SOLUTION: A seal lip part 2 is provided with uniformly rugged parts 6 in its surface coated with a lubricative resin layer 5. This increases the contact area of the lubricative resin layer 5 with the seal lip part 2 and provides an anchor effect where the lubricative resin layer 5 gets in the rugged parts 6 to thereby improve the mutual adhesion of the lubricative resin layer 5 and the seal lip part 2 and avoid their peeling off each other to the utmost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal, and more particularly to an oil seal having a seal lip coated with a lubricating material layer.

[0002]

2. Description of the Related Art In an oil seal, generally, a seal lip portion made of an elastic material such as rubber comes into contact with a mating member to obtain a sealing property. Conventionally, as shown in a sectional view of FIG. , Seal lip 2 and mating member S
In order to reduce friction torque and improve abrasion resistance, a seal lip 2 coated with a lubricating resin layer such as polytetrafluoroethylene (PTFE) resin has been commercialized. (For example, Jikken 57
-27961).

[0003]

Incidentally, in the oil seal coated with the lubricating resin layer 5 as described above, if the degree of adhesion of the lubricating resin layer 5 is insufficient, it may be peeled off depending on the use conditions. There is a problem. Conventionally, in order to increase the degree of adhesion of the lubricating resin layer 5 to the seal lip portion 2, the coated surface of the seal lip portion 2 is washed with a solvent or the like prior to the coating process of the lubricating resin layer 5. However, the above-mentioned problems have not been completely solved.

An object of the present invention is to provide an oil seal in which the degree of adhesion of a lubricating resin layer to a seal lip portion is improved and the lubricating resin layer is less likely to be peeled off even under severe use conditions. It is in.

[0005]

The structure for achieving the above object will be described with reference to FIG. 1 showing an embodiment. The oil seal according to the present invention comprises a seal lip 2 made of an elastic material. In the oil seal coated with the lubricating resin layer 5, the lubricating resin layer 5
Are formed on the surface to be coated by the method described above.

Here, the size (surface roughness) of the unevenness in the present invention is not particularly limited, but is preferably about several μm to several tens μm.

In the structure of the present invention, the unevenness 6 formed on the surface of the seal lip portion 2 to be coated with the lubricating resin layer 5 reduces the contact area between the seal lip portion 2 and the lubricating resin layer 5. At the same time, the adhesion is improved by increasing the adhesion, and at the same time, the anchoring effect due to the penetration of the lubricating resin layer 5 is brought about to improve the adhesion.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part showing a configuration of an embodiment of the present invention.

An inwardly protruding seal lip 2 is integrally formed with a seal body 1 formed of an elastic material such as rubber into an annular shape, and a reinforcing metal core 3 is fixed thereto. A garter spring 4 is fitted around the outer periphery of the seal lip 2.

The sliding surface of the seal lip portion 2 with the mating member S is coated with a lubricating resin layer 5 made of a resin having high lubricity such as PTFE. The surface to be coated of the seal lip portion 2 with the lubricating resin layer 5 includes a surface tens of μm in a predetermined region including the tip (edge portion) of the seal lip portion 2 toward the base side. Small asperities 6 are uniformly formed. The lubricating resin layer 5 is in close contact with the irregularities 6.

The unevenness 6 formed on the surface to be coated of the seal lip portion 2 is transferred by forming a corresponding portion of a molding die on the uneven surface, and the lubricating resin layer 5 is 6 is formed by applying and solidifying a liquid material on the surface to be coated of the seal lip portion 2 where the seal lip 6 is formed.

The surface to be coated of the seal lip portion 2 on which the irregularities 6 are formed is subjected to an acid / alkali treatment or a laser / electron beam irradiation before a coating liquid application step for forming the lubricating resin layer 5. The surface is cleaned by a treatment or a plasma treatment.

Further, as shown in FIG. 2, the cutting step for forming the edge of the tip of the seal lip portion 2 is performed after forming the lubricating resin layer 5 on the seal lip portion 2 on which the irregularities 6 are formed. .

According to the above-described embodiment of the present invention, since the lubricating resin layer 5 penetrates into the irregularities 6 and is in close contact with the seal lip portion 2, the contact area between the two increases and the close contact is made. In addition to the improvement in the degree, the adhesiveness of the lubricating resin layer 5 is greatly improved by the anchor effect, and the possibility of peeling is greatly reduced.

In the above embodiment, the radial type oil seal has been described. However, the present invention is not limited to this, and is widely applied to an oil seal having a seal lip portion which comes into sliding contact with a mating member. Needless to say, the shape of the seal body and the core metal, the presence or absence of a garter spring, and the like are not particularly limited.

[0016]

As described above, according to the present invention, since the surface of the seal lip portion to be coated with the lubricating resin layer is formed with uniform irregularities, the seal lip portion and the lubricating resin layer are As the contact area between them increases, the degree of adhesion between the two improves, and the lubricating resin layer is joined to the seal lip in a state of being stuck in the unevenness, so that the adhesion between the two is enhanced by the anchor effect. improves. As a result, even if oil that easily swells the elastic material forming the seal lip is used or the lubricating resin layer is peeled off even when used at high temperature, the risk of peeling is greatly reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part showing a configuration of an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an example of a manufacturing process according to the embodiment of FIG. 1;

FIG. 3 is a sectional view of a main part of a conventional oil seal in which a lubricating resin layer is formed on a seal lip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Seal main body 2 Seal lip part 3 Core metal 4 Garter spring 5 Lubricity resin layer 6 Unevenness

Claims (1)

[Claims] 1. An oil seal in which a lubricating resin layer is coated on a seal lip portion made of an elastic material, the surface of the seal lip portion to be coated with the lubricating resin layer having uniform unevenness. Characteristic oil seal.