JPH05149330A - Bearing - Google Patents

Abstract

PURPOSE:To provide a bearing suitable for use in a vacuum, where degassing is little and generation of abrasion powder is little particularly when used in a vacuum. CONSTITUTION:In a bearing where a hard ball 21a held by a retainer 21d between an inner race 21d and an outer race 21c is rolled for relative rotation between the inner race 21d and the outer race 21c, an alloy 21f made of at least two kinds of metals which are soft and have low vapor pressure is filled between the inner race 21b and the outer race 21c. There is provided a heater 22 for heating the alloy 21f up to an arbitrary temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing suitable for use in a vacuum, and more particularly to a bearing that is less outgassed when used in a vacuum and that produces less friction powder.

Bearings used in a vacuum container of a vacuum apparatus for manufacturing a semiconductor device are indispensably required to have less degassing and less friction powder.

[0003]

2. Description of the Related Art Next, a conventional bearing intended for use in a vacuum will be described with reference to FIG. Figure 2
FIG. 3A is a diagram for explaining a conventional bearing, and FIG.
Is a sectional view of the bearing, and FIG. 6 (b) is an enlarged sectional view of the hard sphere.

A conventional bearing 11 intended for use in a vacuum or the like has an inner ring 11b, an outer ring 11c, an inner ring 11b and an outer ring 1.
1c and a hard ball 11a held by a cage 11d.

As is clear from the above description, the vacuum bearing 11 has an oil-based grease, which is a lubricant, between the inner ring 11b and the outer ring 11c in order to suppress outgassing in vacuum as much as possible. Etc. were not filled.

Therefore, in the conventional bearing 11, the inner ring is
Even if the lubricant is not filled between 11b and the outer ring 11c, the hard balls 11a should be rolled so that the hard balls 11a can roll smoothly.
For example, a gold film 11a ₂ formed by vapor-depositing a soft metal, for example, gold (Au), was formed on the entire surface of a steel ball 11a _{1 made} of special steel.

[0007]

However, as described above, the conventional bearing 11 composed of the hard spheres 11a whose surface is covered with the gold film 11a ₂ and the like has less degassing in vacuum, There is a problem that the gold film 11a ₂ becomes fine friction powder by the rolling of the 11a and is separated from the steel ball 11a ₁ and scattered around.

In addition to this, there is also a problem that the life is shortened due to deterioration of lubricity due to peeling of the gold film 11a ₂ .
The present invention has been made to solve such a problem, and an object thereof is to provide a bearing that is less outgassed when used in a vacuum and is less likely to generate friction powder. .

[0009]

As shown in FIG. 1, the purpose is to roll the hard balls 21a held by the cage 21d between the inner ring 21b and the outer ring 21c to roll the inner ring 21b and the outer ring 21c.
In a bearing in which and are in relative rotation, the inner ring 21b and the outer ring
An alloy 21f consisting of at least two kinds of soft metal with low vapor pressure is filled between the alloy 21c and
This is achieved by a bearing characterized by comprising heating means 22 for heating 21f to an arbitrary temperature.

[0010]

As shown in FIG. 1, the bearing of the present invention has an inner ring 21b and an outer ring 21c filled with an alloy 21f consisting of at least two kinds of soft metal having a low vapor pressure, and this alloy is also used.
A heating means 22 for heating 21f to an arbitrary temperature is provided.

Therefore, the alloy 21f is heated by the heating means 22 to bring the alloy 21f into a semi-molten state, that is, a solid surface,
For example, alloy 21f in the solid state where the adhesion to the hard spheres 21a is strong and alloy 21f in the liquid phase where the shearing force is low.
The alloy 21f in the state of coexisting with f, that is, the semi-molten alloy 21f will function as a lubricant similar to oil-based grease in the state of low vapor pressure.

Thus, the bearing of the present invention is less degassed even when it is used in a vacuum, less friction powder is generated, and longer life.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bearing according to an embodiment of the present invention will be described below with reference to FIG.
Will be described. FIG. 1 is a schematic sectional view for explaining a bearing according to an embodiment of the present invention.

As shown in FIG. 1, a bearing 20 according to an embodiment of the present invention includes a bearing main body 21 and an alloy of at least two kinds of soft metal having a low vapor pressure in the bearing main body 21, for example, a composition component. Is 50 wt% indium (In) and 50 wt% lead (Pb)
% Indium-lead alloy 21f (semi-molten state 182-
The heating means 22 for heating (210 ° C.) to an arbitrary temperature is included.

The bearing body 21 includes an inner ring 21b, an outer ring 21c, and an inner ring.
21b and the hard ball 21a made of only special steel which is held by the retainer 21d in between the outer ring 21c, as well as fitting the outer peripheral portion to the recessed portion 21c ₁ provided at both ends of the inner peripheral surface of the outer ring 21c, the inner ring 21b
And the outer ring 21c, the side cover 21e in the shape of a coin with a hole in which the inner peripheral end surface is brought close to the inner ring 21c, the above-mentioned indium-lead alloy 21f filled in the space surrounded by the inner ring 21b, the outer ring 21c, and the side cover 21e. It is composed of.

The heating means 22 includes a temperature control device 22a,
Band heater around the outer ring 21c of the bearing body 21
22b, a power line 22c whose one end is connected to the temperature control device 22a and the other end is connected to the band heater 22b, and the side surface of the side cover 21e of the bearing main body 21 is penetrated and the contact portion 22d ₁ is immersed in the indium-lead alloy 21f. In addition, the thermocouple having the other end connected to the temperature control device 22a, for example, an alumel-chromel thermocouple 22d is included.

Therefore, when the bearing 20 of one embodiment of the present invention having the above-mentioned structure is used in a vacuum, its heating means is used.
When the indium-lead alloy 21f of the bearing body 21 is heated by 22 and kept at a temperature of 182 to 210 ° C., for example, 200 ° C., the indium-lead alloy 21f is in a liquid state with the indium-lead alloy 21f in the solid state. It becomes a semi-molten state in which the indium-lead alloy 21f coexists, and due to the reason described above, it functions as a lubricant similar to the oil-based grease in the state of low vapor pressure.

Thus, the bearing 20 of one embodiment of the present invention is
Even when used in vacuum, less degassing occurs, less friction powder is generated, and the life is extended. The bearing 20 of the above-described embodiment of the present invention is an example in which an indium-lead alloy is used as an alloy made of a soft metal with a low vapor pressure, but the composition component is indium (In) 5 wt%. And gallium (Ga) 95 wt%, the difference between the freezing point and the melting point is 10
Indium-gallium alloys above ℃ (semi-molten state 1
Of course, it is also possible to configure by using (5.7 to 25 ° C.).

[0019]

As described above, the present invention makes it possible to provide a long-life bearing with less degassing and less generation of frictional powder even when used in a vacuum.

Therefore, if a vacuum apparatus for manufacturing a semiconductor device is constructed by adopting the bearing of the present invention, the performance of the vacuum apparatus is significantly improved and the semiconductor device and the like can be manufactured with high yield.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view for explaining a bearing according to an embodiment of the present invention,

FIG. 2 is a diagram for explaining a conventional bearing.

[Explanation of symbols]

11 is a bearing, 11a is a hard ball, 11a ₁ is a steel ball, 11a ₂ is a gold film, 11b is an inner ring, 11c is an outer ring, 11d is a retainer, 20 is a bearing, 21 is a bearing body. , 21a is hard ball, 21b is an inner ring, 21c is an outer ring, 21c ₁ is recess, 21d may retainer, 21e is a side cover, 21f include indium - lead alloy (alloy), 22, heated means, 22a is a temperature controller, 22b are band heaters, 22c are power lines, 22 d are alumel - chromel thermocouple (thermocouples), 22 d ₁ shows a contact part, respectively.

Claims (1)

[Claims] 1. A cage between the inner ring (21b) and the outer ring (21c).
By rolling the hard ball (21a) held by (21d), the inner ring
In a bearing in which the (21b) and the outer ring (21c) rotate relative to each other, an alloy (21f) consisting of at least two soft metals with low vapor pressure is filled between the inner ring (21b) and the outer ring (21c). And a heating means (22) for heating the alloy (21f) to an arbitrary temperature.