JPH10131971A - Ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely realize a shock vibration countermeasure, attain improvement of lubricating reliability and attain promoting of extension of a life. SOLUTION: This constitution is formed such that in a ball guide groove 10a of an inner ring 10, ball slide contact surface of a ball 12 and a ball, slide contact surface of a ball guide groove 14b of an outer ring 14, a molybdenum disulfide coating 12a is formed, in an internal peripheral wall of the inner ring 10 and a peripheral wall of the outer ring 14, a molybdenum disulfide coating 10a, 14b is formed, the molybdenum disulfide coating 10a in the internal peripheral wall of the inner ring 10 and the molybdenum disulfide coating 14b in the peripheral wall of the outer ring 14 are respectively brought into direct contact with each metal part of a rotary shaft 11 and a housing 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball bearing suitable for use in an extreme environment such as a space or vacuum environment.

[0002]

2. Description of the Related Art As is well known, an outer space has an ultra-high thermal vacuum environment, and oil or grease used on the ground is used for a rotating mechanism of space-borne equipment mounted on a space vehicle such as an artificial satellite. It is difficult to use a lubrication system. Therefore, a so-called solid lubrication method has been adopted for ball bearings used in outer space, in which a solid lubricant such as molybdenum disulfide is formed on the ball guide grooves and balls of the inner and outer rings to lubricate. .

[0003] When such a solid lubrication type ball bearing is launched into space using a rocket or the like, the assembled equipment flies at a large acceleration against the gravity of the earth and is exposed to a vibration environment. . At this time, vibration occurs in the ball bearing between the balls and the raceway surfaces of the inner and outer races, and between the inner and outer races, the rotating shaft and the fixed housing.

However, in the above-described ball bearing, although a solid lubricant film exists between the raceway surfaces of the inner ring and the outer ring and the ball, damage and the like are effectively prevented.
The vibration between the inner ring and the outer ring, the rotating shaft, and the housing may cause damage, or even if not damaged, may cause abnormal friction (fretting) due to friction caused by contact between the metals.

Therefore, conventionally, a method of applying vacuum grease between an inner ring and an outer ring, a rotating shaft, and a housing to a ball bearing used in outer space to prevent damage and abnormal occurrence due to vibration applied during launching. Is adopted.

However, in the above-described prevention method, there is a possibility that the applied vacuum grease may melt for a long time and may melt between the inner and outer rings and the ball to deteriorate or peel off the solid lubricant film. In addition, there is a problem that the configuration becomes complicated because measures such as a shield structure must be taken. Further, even if measures such as a shield structure are taken, it is difficult to effectively prevent such a problem, and there is a problem that the bearing performance is reduced and the life is shortened.

[0007]

As described above, the conventional ball bearing must be provided with means for preventing vibration and impact, which complicates the construction and reduces the bearing performance and life. Have a problem.

The present invention has been made in view of the above circumstances, and can realize a reliable shock and vibration countermeasure with a simple configuration, improve the reliability of lubrication, and extend the life. It is an object of the present invention to provide a ball bearing as described above.

[0009]

According to the present invention, there is provided a ring-shaped inner ring in which a ball guide groove is provided in an outer peripheral wall, and one of a rotating body and a fixed body is fitted in the inner peripheral wall, and the inner ring is formed in the inner peripheral wall. A ring-shaped outer ring, wherein the other of the rotating body or the fixed body is fitted on the outer peripheral wall, and a ball guide groove is provided on the inner peripheral wall corresponding to the ball guide groove of the inner ring. A ball slidably interposed between the ball guide groove of the inner ring and the ball guide groove of the outer ring, a ball sliding contact surface of the ball guide groove of the inner ring, and a ball sliding contact of the ball guide groove of the outer ring A first solid lubricating film formed on at least one portion of a surface or an outer peripheral surface of a ball; and a second solid lubricating film formed on at least one of an inner peripheral wall of the inner ring and an outer peripheral wall of the outer ring. It consists of ball bearings That.

According to the above structure, when vibration and impact are applied from the outside, the inner ring, the outer ring and the ball are brought into contact via the first solid lubricating film friction to prevent direct contact between the metals. In addition, the inner ring and the outer ring are brought into contact with the rotating shaft and the fixed body via the second solid lubricating film, thereby preventing mutual metal contact. As a result, damage to the inner ring, the outer ring, and the ball due to impact and vibration is effectively prevented, a reliable lubrication operation is ensured, and the life can be extended.

In the present invention, the first solid lubricating film and the second solid lubricating film are formed of the same or similar material. According to the above configuration, if the second solid lubricating film falls off as abrasion powder due to impact or vibration, even if the abrasion powder enters between the inner ring, the outer ring, and the ball, the abrasion powder is not removed. 1 has the same lubricating function as the solid lubricating film, and as a result, the amount of lubricant is increased,
The wear powder is used for the lubrication operation in cooperation with the first solid lubricating film, and the life can be further extended.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a ball bearing according to an embodiment of the present invention. A ring-shaped inner ring 10 has a solid lubricating film for preventing impact and vibration, for example, a molybdenum disulfide coating 10a on its inner peripheral wall.
Is applied, for example, by a sputtering method. A rotating shaft 11 that forms a rotating mechanism (not shown) is fitted to the inner peripheral portion of the inner ring 10. Thus, when the rotating shaft 11 is fitted to the inner peripheral portion of the inner ring 10, the outer peripheral portion thereof comes into contact with the molybdenum disulfide coating 10 a, and the molybdenum disulfide coating 10 a directly contacts the metal portion of the inner ring itself. Is prevented from contacting.

A ball guide groove 10b is formed in the outer peripheral wall of the inner race 10 in the circumferential direction.
, A plurality of balls 12 are slidably accommodated via a retainer 13. Then, on the outer peripheral portion of the ball 12,
A ring-shaped outer ring 14 is provided. A ball guide groove 14 a is formed on the inner peripheral wall of the outer ring 14.
b, and is provided in the ball guide groove 14a.
The ball 12 is slidably housed.

The outer ring 14 has a solid lubricating film for preventing impact and vibration, for example, a molybdenum disulfide coating 14 on its outer peripheral wall.
b is applied, for example, by a well-known sputtering method. A housing 15 of, for example, a space-borne device is fixed to an outer peripheral portion of the outer ring 14. Thus, the housing 15 is partially in contact with the molybdenum disulfide coating 14a in a state where the outer ring 14 is fixed, and the housing 15 can directly contact the metal portion of the outer ring itself by the molybdenum disulfide coating 14a. Will be blocked.

The ball guide groove 10b of the inner race 10
A solid lubricating film for bearing lubrication, for example, a molybdenum disulfide coating 12a (in FIG. 1, For convenience, ball 12
Is shown). Thereby, the rotating shaft 1
1 is driven to rotate, the inner ring 10 is driven to rotate, and in conjunction with this, the ball 12 is moved to the ball guide groove 10 b of the inner ring 10.
And the inner ring 10, the ball 12, and the outer ring 14 are lubricated through the molybdenum disulfide coating 12a (only the portion of the ball 12 is shown), and the ball is stably moved. A rotation drive is performed.

With the above configuration, the inner ring 10 and the outer ring 14
When launched into space with the rotating shaft 11 and the housing 15 assembled, excessive impact and vibration are applied during the launch. Then, the inner ring 10 vibrates with the rotating shaft 11, but does not directly contact the metal part of the rotating shaft 11 due to the action of the molybdenum disulfide coating 10 a. At the same time, vibration occurs between the outer ring 14 and the housing 15, but similarly, the outer ring 14 does not come into direct contact with the metal part of the housing 15 due to the action of the molybdenum disulfide coating 14a.

At this time, it is assumed that frictional powder of the molybdenum disulfide coatings 10a and 14b on the inner peripheral wall of the inner ring 10 and the outer peripheral wall of the outer ring 14 is generated, and the abrasion powder enters between the inner ring 10, the ball 12 and the outer ring 14. The molybdenum disulfide coating 1
Since the wear powders 0a and 14b have a fixed lubrication function, they do not adversely affect the subsequent lubrication function, but rather contribute to an increase in the amount of lubricating material, thereby improving the lubrication life.

As described above, in the ball bearing, the molybdenum disulfide coating 12a (the ball 12) is formed on the ball guide groove 10a of the inner race 10, the ball sliding surface of the ball 12, and the ball sliding surface of the ball guide groove 14b of the outer race 14. Are formed, and the molybdenum disulfide coatings 10a and 14b are formed on the inner peripheral wall of the inner race 10 and the outer peripheral wall of the outer race 14.
The molybdenum disulfide coating 10a on the inner peripheral wall of the inner ring 10 and the molybdenum disulfide coating 14b on the outer peripheral wall of the outer ring 14 are configured to be in direct contact with the metal parts of the rotating shaft 11 and the housing 15, respectively.

According to this, the inner ring 10 and the outer ring 14 are coated with the molybdenum disulfide coatings 10a, 1 even when an excessive impact / vibration is applied, for example, when launching into outer space.
By contacting the rotating shaft 11 and the metal part of the housing 15 via the 4b and not directly, the inner ring 10 and the outer ring 14 are prevented from being abnormally worn (fretting) or damaged, and the reliability is improved. Since a high lubrication operation is ensured and a reliable operation over a long period of time is realized, the life can be extended.

In the above embodiment, a solid lubricating film formed on the inner peripheral wall of the inner race 10 and the outer peripheral wall of the outer race 14 for preventing impact and vibration, the ball sliding contact surface of the ball guide groove 10b of the inner race 10, and the ball 12 and ball guide groove 14 of outer ring 14
Although the molybdenum disulfide coating 12a is formed by a sputtering method as a solid lubricating film for bearing lubrication formed on the ball sliding contact surface a, the present invention is not limited thereto.

That is, the solid lubricating film for preventing shock and vibration is formed on the inner peripheral wall of the inner race and / or the outer peripheral wall of the outer race according to the mounting structure of the rotating shaft 11 and the housing 15. May be configured.

As the solid lubricating film for bearing lubrication, for example, the ball sliding contact surface of the ball guide groove 10b of the inner race 10, the ball 1
If it is formed on at least one of the ball sliding surfaces of the ball guide grooves 14a of the outer ring 14 and the outer ring 14, a desired lubrication function may be able to be secured.

The molybdenum disulfide coatings 10a, 14
As a method for forming b and 12a, a known ion plating method may be used instead of the sputtering method.

Further, in the above embodiment, the molybdenum disulfide coatings 10a, 14b and 12a are used as the solid lubricating films for impact / vibration prevention and bearing lubrication. However, the present invention is not limited to this. May be formed by a sputtering method or an ion plating method.

Also, the solid lubricating film for shock / vibration prevention and bearing lubrication may be formed by bonding and firing the inner peripheral wall of the inner race 10 and the outer peripheral wall of the outer race 14 with molybdenum disulfide as a main component and a binder. You may comprise.

Further, the solid lubricating film for preventing impact / vibration and lubricating the bearing may be formed so as to form a coating of a soft metal material such as gold, silver, lead and the like. The coating of the soft metal material is formed by a plating method, a sputtering method, or an ion plating method.

Further, in the above-described embodiment, the case where the solid lubricating films for impact / vibration prevention and bearing lubrication are formed of the same material has been described. However, the present invention is not limited to this. May be formed using the same kind of different materials.

In the above-described embodiment, the case where the present invention is applied to equipment used in outer space has been described as a representative. However, the present invention is not limited to this, and can be applied to an extreme environment where oil or grease is difficult to use. And an almost similar effective effect is expected.

Further, in the above embodiment, the rotating shaft 11 is fitted to the inner race 10 and the fixed housing 1 is fitted to the outer race 14.
Although the description has been given of the case in which the fixed member 5 is fixed, the present invention is not limited to this, and the fixed side may be fixed to the inner ring 10 and the rotating shaft may be attached to the outer ring 14. Therefore, it is needless to say that the present invention is not limited to the above-described embodiment, and that various modifications can be made without departing from the spirit of the present invention.

[0030]

As described in detail above, according to the present invention, a simple countermeasure against shock and vibration can be realized with a simple configuration.
It is possible to provide a ball bearing capable of improving the lubrication reliability and extending the life.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view of a ball bearing according to an embodiment of the present invention.

[Explanation of symbols]

 10 ... inner ring. 10a, 12a, 14b: Molybdenum disulfide coating. 10b, 14a ... ball guide grooves. 11 ... Rotary axis. 12 ... Ball. 13 ... Cage. 14 ... Outer ring. 15 ... Housing.

Claims (10)

[Claims] A ring-shaped inner ring in which a ball guide groove is provided in an outer peripheral wall, and one of a rotating body and a fixed body is fitted to an inner peripheral wall; the inner ring is inserted into the inner peripheral wall; A ring-shaped outer ring provided with a ball guide groove on the inner peripheral wall corresponding to the ball guide groove of the inner ring, and a ball guide groove of the inner ring; A ball slidably interposed between the ball guide groove of the outer ring and at least a ball sliding contact surface of the ball guide groove of the inner ring, a ball sliding contact surface of the ball guide groove of the outer ring, or an outer peripheral surface of the ball; A ball bearing comprising: a first solid lubricating film formed at one place; and a second solid lubricating film formed on at least one of an inner peripheral wall of the inner ring and an outer peripheral wall of the outer ring. 2. The ball bearing according to claim 1, wherein said first solid lubricant film and said second solid lubricant film are formed of the same or similar material. 3. The ball bearing according to claim 2, wherein the first and second solid lubricating films are formed of a molybdenum disulfide coating or a tungsten disulfide coating. 4. The ball bearing according to claim 3, wherein the molybdenum disulfide coating or the tungsten disulfide coating is formed by a sputtering method. 5. The ball bearing according to claim 3, wherein the molybdenum disulfide coating or the tungsten disulfide coating is formed by an ion plating method. 6. The ball bearing according to claim 1, wherein the first and second solid lubricating films are mainly composed of molybdenum disulfide, and are formed by bonding or firing with a binder. 7. The ball bearing according to claim 1, wherein the first solid lubricant film and the second solid lubricant film are formed of a soft metal material. 8. The ball bearing according to claim 7, wherein the coating of the soft metal material is formed by plating. 9. The ball bearing according to claim 7, wherein the coating of the soft metal material is formed by a sputtering method. 10. The ball bearing according to claim 7, wherein the coating of the soft metal material is formed by an ion plating method.