JPH0634054A - Oil seal - Google Patents

Abstract

PURPOSE:To improve a lubricating condition between the elastic body and the sliding contact fellow, and improve the service life in a contact type oil seal. CONSTITUTION:An oil seal 2 is formed by coating an annular core metal 3 having an approximately L shape upper half cross section with an elastic body 4 such as rubber. On the inner periphery of a main lip 6 being a part of the elastic body 4, a plurality of lubricating oil storing recessed parts 10 are formed on a sliding surface 9 being brought into pressure contact with an outer peripheral surface of a rotary shaft 1. Lubricating oil stored in these recessed parts 10 is transferred to the rotary shaft 1, and forms a lubricating oil film between the rotary shaft 1 and the sliding surface 9 of the main lip 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact type oil seal such as used inside a transmission of an automobile.

[0002]

2. Description of the Related Art Conventionally, in a contact type oil seal, a method of adding a material having wear resistance or low friction property to a material has been adopted in order to suppress wear of the lip or to reduce friction. Countermeasures using such materials are almost limited.

On the other hand, for example, Japanese Utility Model Laid-Open No. 60-974.
As shown in Japanese Patent Laid-Open No. 60, it is considered that a film of a solid lubricant is formed on a sliding contact surface of an oil seal to reduce frictional resistance.

[0004]

By the way, it is pointed out that, in the above-mentioned conventional example, the solid lubricating film is worn out in a relatively short period of time and has a short life.

The present invention was devised in view of the above circumstances, and improves the lubrication state between the elastic body of the oil seal and its sliding contact partner to reduce the friction torque and improve the service life. Is intended.

[0006]

In order to achieve the above-mentioned object, the present invention has the following structure in an oil seal in which an elastic body is attached to an annular core metal.

In the first oil seal of the present invention, a plurality of oil reservoir recesses are provided on the surface of the elastic body that directly contacts the sliding contact.

In the second oil seal of the present invention, the fine particles that peel off due to the abrasion are dispersed and mixed in at least in the vicinity of the sliding contact surface of the elastic body.

In the third oil seal of the present invention, a plurality of oil-storing recesses are provided on the sliding surface of the elastic body that directly contacts the sliding contact partner, and at least the vicinity of the sliding surface of the elastic body is provided. , Fine particles that are separated due to the wear are dispersed and mixed.

[0010]

In the first and third oil seals, the lubricating oil stored in the concave portion of the sliding contact surface of the elastic body is supplied between the sliding contact surface of the elastic body and the sliding contact partner. Therefore, it contributes to the reduction of the frictional resistance of the sliding contact portion, the reduction of the temperature rise of heat generation and the suppression of the wear.

Further, in the case of the second oil seal, since the fine particles are peeled off by the sliding contact partner in the initial stage of use, a concave portion corresponding to the outer shape of the fine particles is formed on the peeling trace. become. This recess functions as described above.

Further, in the case of the third oil seal, when the sliding contact surface of the elastic body is worn away with use, the fine particles mixed in the elastic body are exposed.
As in the case of the second oil seal described above, the fine particles eventually peel off to form a recess.

[0013]

1 and 2 show an embodiment of the present invention. In the figure, 1 is a rotating shaft, and 2 is an oil seal. The oil seal 2 is composed of an annular core metal 3 whose upper half has a substantially L-shaped cross section and which is covered with an elastic body 4 such as rubber. The elastic body 4 has an outer peripheral covering portion 5 for preventing a gap from being formed on a fitting surface of the oil seal 2 with a housing (not shown).
It has a main lip 6 and an auxiliary lip 7.
A garter spring 8 is attached to the outer periphery of the main lip 6, and the main lip 6 is pressed against the outer peripheral surface of the rotary shaft 1 by the tightening force of the garter spring 8 as shown in FIG. There is.

A plurality of recesses 10 for storing lubricating oil are formed in the sliding contact surface 9 that is pressed against the outer peripheral surface of the rotary shaft 1 on the inner periphery of the main lip 6, and is stored in the recesses 10. The lubricating oil is effective in suppressing wear and heat generation of the sliding contact surface 9 of the main lip 6. This recess 10
Can be formed as follows, for example. That is, by forming a plurality of protrusions in a portion corresponding to the sliding contact surface 10 of the molding die, the recesses 10 corresponding to the protrusions are transferred and formed simultaneously with molding. In addition to this, as shown in FIG. 3, fine particles 11 are mixed in advance inside the main lip 6 at the time of manufacturing the oil seal, and cutting in the manufacturing process is performed along a dashed line in the drawing. When this cutting is performed, some of the fine particles 11 are exposed on the sliding contact surface 9 of the main lip 6, so that the exposed fine particles 11 are peeled off at the initial stage of use, and the peeling marks are left. It becomes the recess 10.

The size of the above-mentioned fine particles is preferably set to 0.001 to 0.05 mm, and the material is preferably plastics, bakelite, carbon or the like. With such fine particles, there is no adverse effect on the peripheral mechanical portion after peeling during use.

Further, in addition to forming the concave portion 10 on the sliding contact surface 9 as shown in the drawing, the above-mentioned fine particles 11 may be mixed inside the main lip 6. With this configuration, in the initial stage of use, the lubricating oil in the concave portion 10 of the sliding contact surface 9 is supplied to the sliding contact portion with respect to the rotating shaft 1 to perform lubrication and temperature rise suppression. Then, when the depth of the concave portion 10 becomes shallow due to wear of the sliding surface 9 with time, the fine particles 11 inside the main lip 6 are exposed accordingly, and finally, the fine particles 11 are peeled off and peeled off. The trace becomes a new recess 10. For this reason, the lubricating oil is stored in the newly formed recess 10 and is supplied to the sliding contact portion from here as in the case described above, thereby exhibiting a semipermanently good effect from the initial use. .

The present invention is not limited to the above embodiment. For example, the shape of the core metal 1 and the shapes and numbers of the lips 6 and 7 are arbitrary. The present invention can also be applied to a thrust type oil seal. Further, the shape of the fine particles 11 is arbitrary, and by specifying the shape, the shape of the recess 10 can be appropriately set.

[0018]

As described above, according to the present invention, since the lubricating oil stored in the concave portion of the sliding contact surface is supplied to the sliding contact portion with the counterpart, the sliding contact surface of the elastic body A lubricating oil film is formed between the sliding contact and its sliding contact, which reduces frictional resistance and suppresses wear, which contributes to longer life.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an upper half of an embodiment of an oil seal of the present invention.

FIG. 2 is an enlarged view of a sliding contact portion between the oil seal and the rotary shaft.

FIG. 3 is a vertical sectional view of the upper half showing a state in which the oil seal is being manufactured.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating shaft 2 oil seal 3 annular core metal 4 elastic body 6 main lip 9 sliding contact surface 10 concave portion 11 fine particles

Claims (3)

[Claims] 1. An oil seal comprising a ring-shaped cored bar covered with an elastic body, wherein a plurality of oil-storing recesses are provided on a surface of the elastic body which is in direct sliding contact with a sliding contact partner. An oil seal that is characterized. 2. An oil seal comprising a ring-shaped cored bar covered with an elastic body, wherein fine particles peeling off due to abrasion are dispersed and mixed in at least near the sliding contact surface of the elastic body. The oil seal that is characterized by 3. An oil seal comprising a ring-shaped cored bar covered with an elastic body, wherein a plurality of oil-storing recesses are provided on a surface of the elastic body that directly slides on a sliding contact partner. ,
An oil seal, characterized in that, at least in the vicinity of a sliding contact surface of the elastic body, fine particles that are separated by abrasion are dispersed and mixed.