JPH0470489B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic fluid sealed rolling bearing. The present invention relates to a rolling bearing suitable for use in a shaft for introducing power into a gas atmosphere with a pressure difference.

[Conventional technology]

Conventionally, for example, bearings that support the load of a rotating shaft, seals that prevent contaminants from entering the bearing, or shaft seals that seal pressure differences at a certain point on the shaft each have their own unique functions. Even if there is a part that has multiple functions, it is usually just a simple combination of parts with individual functions. For example, in the bearing disclosed in Japanese Unexamined Patent Publication No. 57-15152, a magnetic fluid seal having an independent structure is provided between the outer ring and the inner ring.

However, such a structure in which parts with individual functions are simply combined and integrated has difficulties in simplifying and compacting the structure of the product.
If an attempt is made to make the device more compact, for example, there will be problems in designing the magnetic fluid seal, making it difficult to obtain sufficient magnetic flux, or increasing the cost.

[Problem to be solved by the invention]

The technical problem of the present invention is to provide the bearing with the above-mentioned sealing function by organically combining the members for performing each function and to provide the desired function with a simple and compact structure. be.

[Means to solve the problem]

In order to solve the above problems, the magnetic fluid sealed rolling bearing of the present invention is constructed by interposing a permanent magnet between a pair of outer ring split rings made of a magnetic material, in which the outer ring is divided into two at the center thereof,
A non-magnetic rolling element is provided between the outer ring and the inner ring, and a non-magnetic rolling element is provided between the inner edge of the magnetic pole plate in contact with the outer surface of the outer ring and the shoulders near both outer peripheral end surfaces of the inner ring to lubricate the rolling element. It is constructed by intervening a magnetic fluid that isolates the vicinity of the rolling elements from the outside without any involvement.

[Effect]

The magnetic flux from the permanent magnet interposed between the pair of outer ring split rings is transmitted between the outer ring split ring made of magnetic material, the magnetic pole plate in contact with its outer surface, and between the inner edge of the magnetic pole plate and the shoulder of the inner ring. It reaches the inner ring via the magnetic fluid interposed in the magnetic fluid, and returns to the permanent magnet via the magnetic fluid, magnetic pole plate, and outer ring dividing ring. This allows the magnetic fluid to exhibit a stable sealing function.

Since the rolling elements that roll between the outer ring and the inner ring are made of non-magnetic material, they are not affected by magnetic flux.

In this magnetic fluid sealed rolling bearing, the outer ring and inner ring of the bearing, which support the load of the rotating shaft, are used as part of the magnetic fluid seal mechanism, that is, members that function as a bearing and a seal. Since they are organically combined, the overall structure is simple and compact, and it is possible to provide the desired functions.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

In the embodiment shown in FIGS. 1 and 2, the outer cylinder 1
The outer ring 2 press-fitted into the inner ring is composed of a pair of outer ring split rings 2a and 2b that are divided into two at the center, and a ring-shaped permanent magnet 3 interposed between them. A large number of balls 6 held by a cage 5 are interposed between the ball 4 and the ball 4. Therefore, the balls 6 come into contact with the pair of outer ring split rings 2a, 2b and the inner ring 4, forming a three-point contact type. In addition, the outer ring split rings 2a, 2b
Annular magnetic pole plates 7a and 7b are brought into contact with the outer surface of the ring, and a magnetic fluid 8 is interposed between the inner edge thereof and the shoulder of the inner ring 4. Note that grease is injected around the ball 6.

In the bearing having the above configuration, the outer ring split rings 2a, 2b and the inner ring 4 are made of a wear-resistant magnetic material such as conventionally commonly used bearing steel or decarburized steel, and The balls 6 are made of silicon nitride or other non-magnetic ceramic material, and the cage 5 is made of a copper alloy such as brass or bronze, or other non-magnetic material. The outer cylinder 1 is made of a non-magnetic material, and the magnetic pole plates 7a and 7b are made of steel or the like.

Therefore, because of the structure in which the balls 6 are interposed between the outer ring 2 and the inner ring 4, the above-mentioned bearing naturally performs its original function of supporting the load of the rotating shaft and causing it to rotate smoothly. However, magnetic pole plate 7
A magnetic fluid 8 interposed between a, 7b and the inner ring 4
constitutes a magnetic fluid seal by the magnetic flux flowing through them, and this magnetic fluid seal isolates the vicinity of the ball 6 from the outside, preventing contaminants from entering the bearing, and It is possible to seal against the atmospheric gas and the pressure difference between both sides.

Moreover, in the above bearing, the outer ring 2 and the inner ring 4 constitute a part of the magnetic path for the magnetic fluid seal, and the magnetic pole plates 7a and 7b are simply brought into contact with the outer surface of the outer ring 2, and the magnetic pole plates Since a magnetic fluid seal is formed between the inner ring 4 and the inner ring 4, its structure is significantly simplified.

3 and 4 show another embodiment of the present invention, in which balls are used as rolling elements in the previous embodiment, but cylindrical rollers 16 are used, and an outer ring split ring 2a is used. , 2b is composed of a large number of magnet pieces 13, 13, . . . , and these magnet pieces 13 are closely arranged between the outer ring split rings 2a, 2b.

Note that the other configurations and operations are substantially the same as those of the previous embodiment, and therefore, the same or corresponding parts are given the same reference numerals and the explanation thereof will be omitted.

〔Effect of the invention〕

As is clear from the detailed description above, according to the present invention, when adding a magnetic fluid seal function to the load supporting function of a conventional rolling bearing, the magnetic fluid sealing function can be applied to the vicinity of the rolling elements without involving the lubrication of the rolling elements. Since it uses a magnetic fluid that isolates the magnetic fluid from the outside, it is possible to freely select and use lubricants whose lubrication performance has been sufficiently confirmed and magnetic fluids that have stable sealing performance. In order to obtain such a magnetic fluid sealed rolling bearing, the outer ring and inner ring of the bearing that supports the load of the rotating shaft are used as part of the magnetic fluid seal mechanism, thereby functioning as a bearing and as a seal. Since the members for performing the functions are organically combined, the overall structure is simple and compact, and it is possible to provide the desired functions.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views and partial sectional views of an embodiment of the present invention, and FIGS. 3 and 4 are longitudinal sectional views and partial sectional views of other embodiments of the present invention. 2...Outer ring, 2a, 2b...Outer ring split ring, 3...
Permanent magnet, 4...inner ring, 6...ball, 7a, 7b...
Magnetic pole plate, 8...Magnetic fluid, 13...Permanent magnet piece, 16
…around.

Claims (1)

[Claims] 1 The outer ring is divided into two at the center, and a permanent magnet is interposed between a pair of outer ring split rings made of magnetic material, and non-magnetic rolling elements are provided between the outer ring and the inner ring, and the above-mentioned A magnetic fluid is interposed between the inner edge of the magnetic pole plate that contacts the outer surface of the outer ring and the shoulders near both end surfaces of the outer periphery of the inner ring, which isolates the vicinity of the rolling element from the outside without participating in the lubrication of the rolling element. A magnetic fluid sealed rolling bearing characterized by: