JPH0612874U - Sealing device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a contact-type sealing device, a lubricating film is constantly formed on the outer peripheral surface of the inner rotating body such as the inner ring and rotating shaft to increase friction resistance and premature wear of the lip. Prevent. In a sealing device having a contact lip 1 with an outer peripheral surface of an inner rotating body 2, a lip sliding contact surface of the inner rotating body 2 is
The fine protrusions 3 and 4 having a shape that is long in the axial direction or a shape that does not have directionality are formed in a surface state in which there are discrepancies in the rotation direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a contact-type sealing device that is mounted inside a bearing or in the vicinity of the bearing, and more particularly to a fine structure of a surface portion of an inner rotating body with which a lip slides.

[0002]

[Prior art]

 Conventionally, a bearing is often equipped with a sealing device as shown in FIG. In the figure, reference numeral 21 is an inner ring, 22 is an outer ring, 23 is a ball as a rolling element, and 24 is a cage. The sealing device 25 includes a fixed ring 26 fixed to the outer ring 22 as a core metal, and a seal body 28 having a lip 27 integrally attached thereto by baking, and the lip 27 is in sliding contact with the outer peripheral surface of the inner ring 21. It is like this.

[0003]

[Problems to be solved by the device]

 By the way, in the above-mentioned sealing device, the outer peripheral surface of the inner ring 21 with which the lip 27 is slidably contacted is polished along the circumferential direction during the surface processing, so that the surface is rotated as shown in FIG. There are innumerable minute projections 29 that are long in the direction, and the recesses are linearly continuous between the projections 29.

In such a sealing device, a lubricant is filled on the inner side in the axial direction. The lubricant passes through the concave portion between the convex portions 29 on the outer peripheral surface of the inner ring 21 with which the lip 27 slides. It tends to flow in the rotation direction, and as a result, it is often pushed out from the sliding contact path of the lip 27. Therefore, at the lip sliding contact portion of the inner ring 21, it is difficult to form a lubricating film, the frictional resistance increases, and the lip 27 wears faster.

Such a problem also occurs in a sealing device as shown in FIG. 5, which directly seals around the rotating shaft. In the figure, reference numeral 30 is a rotary shaft, 31 is a housing, a bearing 32 is mounted between the two, and a sealing device 33 is provided on the axially outer side of the bearing 32. This sealing device 33 is provided with a fixed ring 34 which is a core metal and a seal body 35 as in the case of FIG. 3, and a lip 36 which is a part of the seal body 35 is provided on the outer peripheral surface of the rotary shaft 30. It is designed to come into sliding contact. 37 is a backup spring.

Also in this sealing device 33, since the outer peripheral surface of the rotary shaft 30 with which the lip 36 is in sliding contact is polished in the rotational direction, it is difficult to form a lubricating film on the surface, and the lip that slides into contact therewith Early wear of 36 is likely to occur.

The present invention addresses the above-mentioned conventional problems and increases the frictional resistance by constantly forming a lubricating film on the outer peripheral surface of the inner rotating body such as the inner ring and the rotating shaft. Another object is to prevent early wear of the lip.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a sealing device having a contact lip that slidably contacts an outer peripheral surface of an inner rotary body, wherein the lip slidable contact surface of the inner rotary body has an axially long shape or a directional property. A fine convex portion having no shape is formed in a surface state in which there is a discrepancy in the rotation direction.

[0009]

[Action]

 In the above-mentioned configuration, on the outer peripheral surface of the inner rotating body, the fine convex portions are arranged in a gap shape, and the concave portions therebetween are divided by the convex portions and are not continuous linearly in a long direction in the rotation direction. Therefore, the lubricant is prevented from flowing in the rotational direction and forms a lubricating film on the spot. Due to the presence of this lubricating film, the lip comes into sliding contact with the inner rotating body with less resistance.

[0010]

【Example】

 Hereinafter, the details of the present invention will be described based on each embodiment shown in FIGS.

FIG. 1 is an enlarged side view of a lip sliding contact portion of a sealing device according to a first embodiment of the present invention. Reference numeral 1 is a lip, and 2 is an inner rotating body such as an inner ring or a rotating shaft. The sealing device of this embodiment is fixed to an outer member such as an outer ring or a housing, and has a lip on its inner diameter side that is in sliding contact with the outer peripheral surface of the inner rotating body. Since it is the same as the sealing device, illustration of the entire structure is omitted.

The sealing device of this embodiment is characterized by the surface state of the lip sliding contact surface of the inner rotating body 2. The lip sliding contact surface is different from the conventional one in that it has a fine shape with a long shape in the axial direction. There are a large number of convex portions 3, and these convex portions 3 are located in a distorted shape with respect to the rotation direction.

In the surface state as described above, for example, the inner rotating body 2 is applied to the rotary grindstone in the axial directions orthogonal to each other, and the outer peripheral surface of the inner rotating body 2 is polished along the axial direction. Therefore, it can be formed. It can also be formed by photoetching.

In the above configuration, on the outer peripheral surface of the inner rotating body 2, the fine convex portions 3 are arranged in a gap in the rotation direction, and the concave portions therebetween are shortly divided or blocked by the convex portions 3 to rotate. The direction is not linear. Therefore, the lubricant is prevented from flowing in the rotation direction on the outer peripheral surface of the inner rotating body 2 and remains there and forms a lubricating film. Due to the presence of this lubricating film, the lip 1 comes into sliding contact with the inner rotating body 2 with little resistance.

In the first embodiment, the fine protrusions 3 having a long shape in the axial direction are provided on the outer peripheral surface of the inner rotating body 2. However, the shape of the protrusions and the arrangement state thereof are such that the recesses between the protrusions are different from each other. Any surface may be used as long as it is not continuous linearly in the rotation direction, and the surface state as shown in FIG.

FIG. 2 is an enlarged side view of a lip sliding contact portion of a sealing device according to a second embodiment of the present invention. In this embodiment, a large number of fine projections 4 having a non-directional shape are formed on the lip sliding surface of the inner rotating body 2, and these projections 4 are randomly arranged so as to be different from the rotation direction. positioned. Such a surface state is formed by, for example, photo etching.

Also in the sealing device of this embodiment, similarly to the first embodiment, the concave portion between the convex portions 4 is divided or blocked on the outer peripheral surface of the inner rotating body 2 to form a linear shape in the rotation direction. Since the lubricant does not continue for a long time, the lubricant is less likely to flow in the rotation direction and forms a lubricant film on the spot. The lubricating film reduces the frictional resistance to the lip 1.

[0018]

[Effect of device]

 As described above, according to the present invention, since the lubricant is retained on the lip sliding contact surface of the inner rotating body and the lubricating film is constantly formed, the frictional resistance is reduced and the lip speed is reduced. Wear can be prevented.

[Brief description of drawings]

FIG. 1 is an enlarged side view of a lip sliding contact portion of a sealing device according to a first embodiment of the present invention.

FIG. 2 is an enlarged side view of a lip sliding contact portion of a sealing device according to a second embodiment of the present invention.

FIG. 3 is a sectional view of an entire sealing device according to a conventional example.

FIG. 4 is an enlarged side view of a lip sliding contact portion of the conventional example.

FIG. 5 is an overall sectional view of a sealing device according to another conventional example.

[Explanation of symbols]

 1 Lip 2 Inner rotator 3, 4 Convex part

Claims (1)

[Scope of utility model registration request] 1. A sealing device having a contact lip slidably contacting an outer peripheral surface of an inner rotating body, wherein a lip slidable contact surface of the inner rotating body is a fine protrusion having a shape elongated in an axial direction or a shape having no directivity. The sealing device is characterized in that the portion is formed in a surface state in which there is a gap in the rotation direction.