JP2577216Y2 - Rolling bearings for use in magnetic field environments - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing which can be suitably used as a bearing for a mechanical oscillating part even in a magnetic field environment, and is particularly characterized by the material of the inner and outer rings and the rolling element between these two wheels. Related to rolling bearings.

[0002]

2. Description of the Related Art Such a rolling bearing is generally used as a component of a mechanical oscillating portion in a special environment such as a magnetic field environment. And beryllium copper such that all parts such as rolling elements between these two wheels are not affected by magnetism,
Alternatively, it is formed of a metal such as non-magnetic stainless steel (SUS304).

[0003]

By the way, in a conventional rolling bearing in which parts are made of metal as described above, in a conventional rolling bearing, a minute area is rapidly shaken in a magnetic field environment like a valve opening / closing actuator, for example. When used as a bearing for a moving oscillating part, so-called pseudo indents are generated at a relatively early stage in a minute area that comes into contact with the rolling elements, particularly on the raceway surfaces of the inner and outer rings, and this pseudo indentation is a cause. An operation failure may occur, and it is desired to investigate the cause of the failure.

As a cause of such pseudo indentation, the present inventors have studied and found that the rolling bearing is used to support a high-speed oscillating portion in a minute area, so that the inner and outer rings and the rolling bearing are used. It has been speculated that this is because sliding contact occurs between the moving object and the rolling object, instead of rolling contact.

The present invention has been made to solve the problem of such a rolling bearing, that is, an early operation failure due to a false indentation based on the above guess, and is a special case of a magnetic field environment. In a harsh environment, such as supporting a high-speed oscillating portion in a small area, the purpose is to be able to stably support the oscillating portion without causing malfunction for a long period of time. I have.

[0006]

In order to achieve the above object, the present invention has the following configuration.

In the present invention, the inner and outer races are made of beryllium copper .
It is characterized in that the rolling elements provided between the two wheels are formed of non-magnetic ceramics.

[0008]

The inner and outer races and the rolling elements that are in contact with each other are made of different materials. Moreover, since the rolling elements are made of ceramics, the weight of the rolling elements is smaller than that of the inner and outer rings (beryllium copper). Therefore, the rolling element can easily follow the high-speed swing, so that the rolling element comes into rolling contact with the inner and outer rings. In addition, since the rolling elements are ceramics, the fact that the rolling elements themselves are hard and have low frictional resistance with a contact partner is also effective in suppressing wear. In addition,
Outer ring (Beryllium copper) is better than rolling element (ceramic)
Shaft to which inner and outer rings are attached due to large linear expansion coefficient
Metal with high coefficient of linear expansion is used for the part and housing part
Even if it is, the circle that causes damage on the inner ring side
No circumferential stress is applied.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. In this embodiment, a deep groove ball bearing is taken as an example. In the figure, 1 is a rotating shaft, 2 is a bearing housing, and 3 is a deep groove ball bearing. The deep groove ball bearing 3 includes an inner ring 4 and an outer ring 5.
, A plurality of balls 6, and a waveform holder 7. The inner ring 4 and the outer ring 5 are formed of beryllium copper, and the balls 6 are ceramics (a sintered body mainly composed of silicon nitride).
It is formed with. The retainer 7 is made of non-magnetic stainless steel (S
US304).

FIG. 2 shows the result of an operation test of the deep groove ball bearing having this configuration. FIG. 3 shows test results when all of the inner / outer rings and the balls were formed of beryllium copper. These results are obtained by measuring the roughness of the raceway surfaces of the inner and outer rings 4 and 5 and the outer peripheral surface of the ball 6 after high-speed rocking in a minute area. 2A and 3A show the measurement results of the inner raceway surface, and FIGS.
(B) shows the measurement result of the outer raceway surface, and (c) of FIGS. 2 and 3 show the measurement result of the ball outer peripheral surface.

The bearing used is model number 686. The test conditions are as shown in FIG. 1, with a radial load of 2 kgf, a swing angular velocity of 230 deg / sec, and a lubricant used for jet engine oil. And in this embodiment, 5
The measurement was performed at the time when 00 hours had elapsed, and in the comparative example, the measurement was performed at the time when 200 hours had elapsed.

As is apparent from the drawing, in the case of this embodiment,
Although almost no pseudo indentations are generated, in the case of the comparative example, it can be seen that large pseudo indents are generated although the test time is much shorter than in this example. From this result, in the case of the present embodiment, the ball 6 is made of ceramics, and its mass is smaller than half that of beryllium copper or bearing steel, so that the ball 6 can easily follow high-speed oscillation. It can be assumed that the rolling contact is made almost regularly without sliding on the inner and outer rings 4 and 5.

The present invention is not limited to the above embodiment. For example, the present invention can be applied to a configuration in which the cage 7 is not used, or a roller bearing that uses a roller as a rolling element .

[0015]

[Effects of the Invention] As described above, according to the present invention,
By specifying the material of the bearing components, the rolling elements can regularly contact the inner and outer rings even during high-speed swinging, so that false indentations are less likely to occur on the inner and outer rings and the rolling elements. The swinging portion can be stably supported without causing malfunction. As described above, the rolling bearing of the present invention exhibits sufficient durability even under severe use conditions.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a deep groove ball bearing of the present invention.

FIG. 2 is an explanatory diagram showing test results of the present embodiment.

FIG. 3 is an explanatory diagram showing test results of a conventional example.

[Explanation of symbols]

 4 inner ring 5 outer ring 6 ball 7 cage

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-112820 (JP, A) JP-B 64-2815 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16C 33/32 F16C 33/62 C04B 33/00 C22C 9/00

Claims (1)

(57) [Scope of request for utility model registration] The inner and outer rings are both made of beryllium copper , and the rolling elements disposed between the two wheels are non-magnetic.
A rolling bearing for use in a magnetic field environment, which is made of ceramics.