JPH07190075A - Solid lubricated rolling bearing - Google Patents

Abstract

PURPOSE:To provide a solid lubricated rolling bearing minimized in generation of dust, suitably usable to a device requiring a pure atmosphere such as a semiconductor manufacturing device, and also usable even in the vacuum state. CONSTITUTION:A plurality of rolling bodies 4 are rotatably held between an inner ring 2 and an outer ring 3 through a holder 5, and a shield plate 6 containing at least fluorine resin is arranged to make contact with the holder 5 to constitute a rolling bearing 1. According to the rotation of the rolling bearing 1, abrasive grains cut from the shield plate 6 are transferred to the raceway surfaces of the inner ring 2 and the outer ring 3, the pocket inner circumferential surface of the holder 5 and the rolling surfaces of the rolling bodies 4 to form a lubricating film.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid lubrication rolling bearing, and more particularly to a solid lubrication rolling bearing which is suitable for use in semiconductor manufacturing equipment and other equipment that requires a clean atmosphere and which can be used even in a vacuum state.

[0002]

2. Description of the Related Art A rolling bearing having a structure that uses oil or grease as a lubricant can withstand high speed rotation and a large load because of its excellent lubricity, but on the other hand, oil and grease scatter as the bearing rotates, Alternatively, it has the drawback that it cannot be used when it is exposed to a vacuum condition or a device that requires a clean environment such as a clean room or semiconductor manufacturing device, because it pollutes the external environment of the bearing due to vaporization due to temperature rise. There is.

Therefore, in a clean room, a semiconductor manufacturing apparatus, or a vacuum state, a bearing having a solid lubricating film formed on the raceway surface or the surface of the rolling element is used. As the solid lubricating film, gold, silver, lead, molybdenum disulfide, tungsten disulfide or fluororesin is generally used.
Among these lubricating films, gold, silver, lead and fluororesin are gradually scraped off from the original film-forming surface by the frictional force generated by the rotation of the bearing, and the wear particles scraped off against each other. Lubrication is performed by transferring to a surface and forming a thin film on the surface.

On the other hand, molybdenum disulfide and tungsten disulfide are layered and have a cleavage plane by themselves, and the cleavage plane gradually wears to exhibit lubricity.

[0005]

By the way, in recent years, various electronic devices such as semiconductor devices have tended to be miniaturized and highly integrated, and accordingly, a small amount of particles has a great influence on product performance and reliability. Has become. For this reason, there is a tendency for the demand for low dust generation to increase more and more for bearings used in a clean environment such as semiconductor manufacturing equipment.

However, all the above solid lubricating films are self-sacrificing type lubrication, and the generation of wear particles is unavoidable.
The situation is not sufficient to meet the above demands. Therefore, it is an object of the present invention to provide a solid lubrication rolling bearing which is suitable for use in an apparatus that requires a clean atmosphere, such as a semiconductor manufacturing apparatus, which produces little dust, and which can be used even in a vacuum state.

[0007]

The above object is to rotatably hold a plurality of rolling elements through a retainer between an outer ring and an inner ring, and further to provide a shield plate containing at least a fluororesin to the retainer. A rolling bearing arranged so as to come into contact with the rolling bearing, and wear particles scraped off from the shield plate as the rolling bearing rotates, raceway surfaces of the outer ring and the inner ring, and a pocket inner peripheral surface of the cage. And a solid lubricated rolling bearing characterized by forming a lubricating coating by transferring to the rolling surface of the rolling element.

Further, for the same purpose, a plurality of rolling elements are rotatably held between the outer ring and the inner ring, and a shield plate containing at least fluororesin is disposed so as to come into contact with the rolling elements. In the rolling bearing, wear particles scraped off from the shield plate with the rotation of the rolling bearing are transferred to the raceways of the outer ring and the inner ring and the rolling surfaces of the rolling elements to form a lubricating coating. It is also achieved by a solid lubricated rolling bearing characterized by.

[0009]

[Operation] According to the present invention, since the cage and the shield plate or the rolling element and the shield plate are in contact with each other, the shield plate is gradually scraped as the bearing rotates, and wear particles are generated inside the bearing. . The wear particles are a lubricating substance such as fluororesin contained in the shield plate, and are transferred to the raceway surface and the rolling element surface to form a thin film having lubricity. Moreover, since wear particles are continuously generated with the rotation of the bearing, a stable lubricating action can be maintained.

Further, since the wear particles are prevented from scattering outside the bearing by the shield plate, the environment outside the bearing is not polluted.

[0011]

EXAMPLES The present invention will be described in detail based on examples. However, the present invention is not limited to the following examples. FIG. 1 is a cross-sectional view of essential parts showing a first embodiment of a solid lubrication rolling bearing according to the present invention. Rolling bearing 1
Includes a plurality of rolling elements 4 arranged between the inner ring 2 and the outer ring 3, and the corrugated press retainer 5 holds the rolling elements 4 at equal intervals along the circumference of the bearing 1.

The present invention is further characterized in that a shield plate 6 which comes into contact with the corrugated press holder 5 is additionally provided. The shield plate 6 has a substantially convex cross-section protruding toward the corrugated press cage 5 as shown in the drawing, and has an inner ring 2 and an outer ring 3
It is an annular plate-like member whose width is the difference in diameter from. The shield plate 6 contains a solid lubricant such as fluororesin, and the corrugated press cage 5 rotates as the rolling bearing 1 rotates,
By sliding on the cage 5, the surface of the shield plate 6 is scraped and wear particles composed of a solid lubricant are generated.
The generated wear particles are applied to the outer peripheral surface (raceway surface) of the inner ring 2, the inner peripheral surface (raceway surface) of the outer ring 3, the inner peripheral surface of the pocket of the corrugated press cage 5 and the surface (rolling surface) of the rolling elements 4. It is transformed to form a film having lubricity. Moreover, since the wear particles are gradually and continuously generated as the rolling bearing 1 rotates, the lubricant is replenished at any time, and the lubricating action is stably maintained.

The solid lubricating rolling bearing 1 according to the present invention
Has a lubricating effect with the rotation of the bearing 1, so that sufficient lubricity may not be obtained in the initial stage of use. In that case, the surface of the rolling element 4 and the inner ring 2 and the outer ring 3 may be preliminarily prepared. By forming a solid lubricating film similar to the conventional one on the raceway surface and the inner peripheral surface of the pocket of the corrugated press holder 5,
The lubricity at the beginning of use can be improved.

Further, since the wear particles are prevented from scattering by the shield plate 6 to the outside of the rolling bearing 1, the environment outside the bearing 1 is not polluted. Since there is a gap (labyrinth) 7 having a minute width between the inner ring 2 side end portion of the shield plate 6 and the inner ring 2, there is no contact friction and
Since it is a minute space, scattering of wear particles to the outside is suppressed.

Although FIG. 1 shows an example in which the shield plate 6 is fixed to the outer ring 3, the same effect as above can be obtained by fixing the shield plate 6 to the inner ring 2 as shown in FIG. Although both the shield plates 6 are in sliding contact with the cage 5 in the embodiments of FIGS. 1 and 2, only one of them may be in contact. FIG. 3 is a half cross-sectional view of a main part showing a modified example of the rolling bearing 1 shown in FIGS. 1 and 2, in which a spacing body (separator) 8 is used in place of the corrugated press cage 5 for rolling elements. 4 shows a structure holding 4. The spacing body 8 is a member made of metal and holds the rolling elements 4 at equal intervals along the circumference of the bearing 1, and functions similarly to the corrugated press cage 5.

The shield plate 6 is attached to the inner ring 2 or the outer ring 3 so as to come into contact with the spacer 8, and as the rolling bearing 1 rotates, the shield plate 6 and the spacer 8 slide to generate wear particles. Then, the wear particles are transferred to the outer peripheral surface of the inner ring 2, the inner peripheral surface of the outer ring 3, the inner peripheral surfaces of the pockets of the spacers 8 and the surface of the rolling elements 4 to form a coating having lubricity. Figure 4
FIG. 4 is a cross-sectional view of a main part showing a second embodiment of the solid lubrication rolling bearing 1 according to the present invention. The rolling bearing 1 does not require the corrugated press retainer 5 or the spacer 8 in the configuration of the first embodiment. That is, the rolling bearing 1 has a structure in which a plurality of rolling elements 4 are arranged between the inner ring 2 and the outer ring 3, and the rolling elements 4 are directly held by the shield plate 6.
Here, although the shield plate 6 is fixed to the outer ring 3 in the illustrated example, it may be fixed to the inner ring 2.

At least one of the shield plates 6 is in contact with the rolling element 4, and the surface of the shield plate 6 is scraped by sliding on the rolling element 4 as the rolling bearing 1 rotates. Wear particles made of a solid lubricant are generated, and these wear particles are transferred to the outer peripheral surface of the inner ring 2, the inner peripheral surface of the outer ring 3, and the surface of the rolling elements 4 to form a film having lubricity, thereby exhibiting a lubricating action. To do.

FIG. 5 is a schematic view of the dust test apparatus used in the present invention. The test bearings 9 are mounted in pairs in the housing 11 via the spring 10, and are rotated by the rotation introducing machine 12 with a magnetic fluid seal. The dust generated from the test bearing 9 due to the rotation is collected in a funnel 13 provided at the lower part of the device, and then sent to a light scattering type particle counter 14 to count the number of dust particles. (Examples 1 to 3 and Comparative Examples 1 to 4)
The inner ring 2 and the outer ring 3 were made common, and the shield plate 6 was made by changing the material and shape thereof as shown in Table 1, and a dusting test was conducted using the dust tester shown in FIG. The test results are also shown in Table 1.

[0019]

[Table 1]

The above test conditions are as follows.・ Test bearing 608 ・ Axial load 9.8N ・ Rotational speed 300rpm ・ Atmosphere In the air From the above test results, a shield plate containing fluororesin (PTFE: polytetrafluoroethylene, PFA: tetrafluoroethylene / perfluoroalkyl vinyl ether polymer) 6 and the corrugated press holder 5, or the shield plate 6
Rolling bearing 1 configured to contact the rolling element 4 with the rolling element 4
It can be seen that (Examples 1 to 3) are remarkably superior in the amount of dust generation and the life of dust generation as compared with the case where both members are not in contact (Comparative Examples 1 to 4).

[0021]

According to the present invention, since the cage of the bearing and the shield plate or the rolling element and the shield plate are in contact with each other, the shield plate is gradually scraped as the bearing rotates,
Wear particles made of a lubricating substance such as fluororesin contained in the shield plate are generated inside the bearing, and the wear particles are transferred to the raceway surface and the rolling element rolling surface to form a thin film having lubricity.
Moreover, since the wear particles are continuously generated in association with the rotation of the bearing, a stable lubricating action can be maintained.

Further, since the wear particles are prevented from scattering to the outside of the bearing by the shield plate, they are not used to pollute the environment outside the bearing, and are suitable for use in semiconductor manufacturing equipment and the like which require a clean atmosphere. It can also be used in a vacuum state. Further, since the shield plate is simply attached to a conventional bearing, and the shield plate itself can be easily manufactured by scraping or injection molding, the cost performance is excellent.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing a first embodiment of a solid lubrication rolling bearing according to the present invention.

2 is a cross-sectional view of essential parts showing a modified example of the solid lubrication rolling bearing shown in FIG.

3 is a half cross-sectional view of essential parts showing another modified example of the solid lubrication rolling bearing shown in FIG.

FIG. 4 is a cross-sectional view of essential parts showing a second embodiment of the solid lubrication rolling bearing according to the present invention.

FIG. 5 is a schematic view showing a dust test apparatus used in the present invention.

[Explanation of symbols]

 1 rolling bearing 2 inner ring 3 outer ring 4 rolling element 5 retainer 6 shield plate 7 gap 8 spacing element 9 test bearing 10 spring 11 housing 12 rotation induction machine with magnetic fluid seal 13 rotor 14 particle counter

Claims (2)

[Claims] 1. A plurality of rolling elements are rotatably held via a cage between an outer ring and an inner ring, and a shield plate containing at least fluororesin is disposed so as to come into contact with the cage. In the rolling bearing, wear particles scraped off from the shield plate as the rolling bearing rotates, race particles of the outer ring and the inner ring, an inner peripheral surface of a pocket of the cage, and a rolling surface of the rolling element. A solid lubrication rolling bearing characterized in that it forms a lubricating coating by being transferred to. 2. A rolling bearing in which a plurality of rolling elements are rotatably held between an outer ring and an inner ring, and a shield plate containing at least a fluororesin is disposed so as to come into contact with the rolling elements. Wear particles scraped off from the shield plate as the rolling bearing rotates, transfer to the raceways of the outer ring and the inner ring and the rolling surfaces of the rolling elements to form a lubricating coating. Lubricated rolling bearing.