JP2566426Y2 - Ceramic bearing rings - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION This ceramic bearing ring constitutes a rolling bearing incorporated in a rotary support portion of various types of machinery.

[0002]

2. Description of the Related Art Various types of mechanical devices are incorporated into a rotary support portion,
As a bearing for supporting a rotating member such as a rotating shaft, a rolling bearing as shown in FIG. 3 is widely used. The rolling bearing 1 is provided so as to roll freely between an inner race 3 having an inner raceway 2 on an outer peripheral surface, an outer race 5 having an outer raceway 4 on an inner peripheral surface, and the inner raceway 2 and the outer raceway 4. It is composed of a plurality of rolling elements 6, 6 and a retainer 7 for holding the plurality of rolling elements 6, 6 so as to freely roll.

[0003] The relative rotation between the inner race 3 and the outer race 5 is free based on the rolling motion of the plurality of rolling elements 6, 6. Therefore, the inner race 3 is externally fixed to a rotating shaft, and the outer race 5 is fixed. If the rotation shaft is fixed inside the housing, the rotation shaft can be rotatably supported inside the housing.

[0004] Of the rolling bearings 1 used in a high temperature region, the components 3, 3
In some cases, the inner ring 3, the outer ring 5, the rolling element 6, and the inner ring 3, the outer ring 5, and the rolling elements 6, 6 are made of ceramic.
The shape 6 and the dimensional accuracy of the members 3, 5, and 6 are insufficient if only the shape 6 is used.

[0005] For this reason, conventionally, the inner ring 3, the outer ring 5, and the rolling elements 6, 6 slightly larger than desired values have been manufactured by sintering ceramic powder.
By applying a polishing process to the surface of each member, the shape accuracy and dimensional accuracy of each of the members 3, 5, and 6 were regulated to desired values.

[0006]

However, it is difficult to finish the shape accuracy and dimensional accuracy of each of the members 3, 5, and 6 to desired values by polishing the ceramic which is harder than the bearing steel and which is polished. Inevitably, it takes a long time for the machining operation. For this reason, the manufacturing costs of the members 3, 5, and 6 increase, and the rolling bearing formed by combining the members 3, 5, and 6 becomes expensive.

The toughness of each of the members 3, 5, 6 made of ceramic, especially the races such as the inner race 3 and the outer race 5, is as follows.
Because the toughness of the bearing ring made of bearing steel is lower than that, if the corner of the ceramic bearing ring collides with the corner of another product during transportation work, the corner of the bearing ring will be chipped. Is liable to occur.

Further, since the coefficient of linear expansion of ceramic is lower than the coefficient of linear expansion of metal, due to the difference in coefficient of linear expansion, the fitting between the raceway ring made of ceramic and the rotating shaft or housing made of metal is performed. The joint strength may be reduced and creep may occur on the mating surface.

The ceramic race of the present invention eliminates any of the above disadvantages.

[0010]

SUMMARY OF THE INVENTION The ceramic race of the present invention is formed in a ring shape entirely of ceramic, and has a raceway formed on one peripheral surface. Further, at the ceramic bearing ring of the present invention, on the other peripheral surface and the end face, to form a sprayed coating of metal, Rutotomoni finishing the surface of the sprayed coating to the desired dimensional accuracy, even after finishing the Spray coating
It is characterized by leaving it on the surface.

[0011]

In the case of the ceramic race of the present invention configured as described above, the shape and dimensional accuracy of the race can be regulated to desired values by processing the surface of the metal spray coating.
The finish processing of the ceramic race is easy, and the production cost can be reduced.

Further, since the other peripheral surface and the end surface, which are likely to collide with other articles, are covered with a sprayed coating of a metal having high toughness, the rolling bearing formed of the ceramic race is transported and the like. In addition, the possibility that the corner of the ceramic race is chipped is reduced.

Further, since the other outer peripheral surface of the rotating shaft and the inner peripheral surface of the housing, which are fitted with the inner peripheral surface of the housing, are covered with a metal sprayed coating, the outer peripheral surface is fitted based on a difference in thermal expansion (thermal contraction). The mating portion is not easily loosened, and creep is less likely to be generated on the mating surface, so that the rolling bearing is reliably supported.

[0014]

FIG. 1 shows a first embodiment of the present invention. The inner ring 3 and the outer ring 5 that constitute the rolling bearing 1 together with the plurality of rolling elements 6 are both made of ceramic. Of these, the inner peripheral surface 3a and both end surfaces 3b and 3b of the inner race 3 and the outer peripheral surface 5a and both end surfaces 5b and 5b of the outer race 5 are all
It is covered with thermal spray coatings 8a and 8b of a metal having sufficient heat resistance such as stainless steel.

When forming each of the thermal spray coatings 8a and 8b, first, a thermal spray coating having a thickness dimension larger than necessary is formed, and then the surface of each thermal spray coating is polished to thereby form each of the thermal spray coatings 8a and 8b. Shape and dimensions are as desired. The desired shape and size of each of the sprayed coatings 8a and 8b are obtained, and the sprayed coating is finished even after finishing.
The films 8a and 8b are left on the processing surface .

That is, the sprayed coating 8a on the surface of the inner ring 3 is first formed to have an inner diameter smaller than the desired inner diameter R and a width larger than the desired width W, and then the surface of the sprayed coating 8a is polished. The inner diameter of the sprayed coating 8a is R, and the width is W.
And finish each. Needless to say, the inner diameter of the ceramic constituting the main body portion of the inner ring 3 is larger than the inner diameter R, and the width of the ceramic is also smaller than the width W.

The thermal spray coating 8b on the surface of the outer ring 5 is first formed into an outer diameter larger than a desired outer diameter D and a width larger than a desired width W, and then the surface of the sprayed coating 8b is polished. Therefore, the outer diameter of the thermal spray coating 8b is D, the width is W,
Finish each. Needless to say, the outer diameter of the ceramic constituting the main body of the outer ring 5 is smaller than the outer diameter D, and the width of the ceramic is also smaller than the width W.

A plurality of rolling elements 6 are attached to the inner race 3 and the outer race 5 which are the ceramic races of the present invention constructed as described above.
The operation itself of the rolling bearing configured by adding the rotatable shaft inside the housing so as to be rotatable is the same as that of the above-described conventional rolling bearing.

Particularly, in the case of the rolling bearing 1 constituted by the inner ring 3 and the outer ring 5 according to the embodiment of the present invention, the inner ring 3
In addition, the shape accuracy and dimensional accuracy of the outer ring 5 can be regulated to desired values by polishing the surfaces of the metal spray coatings 8a and 8b covering the respective surfaces. The operation of polishing the metal surface is much easier than the operation of polishing the ceramic surface, so that the finish processing of the ceramic race is facilitated and the production cost can be reduced.

Also, when the rolling bearing 1 is transported or the like, even if the inner peripheral edge of the inner ring 3 or the outer peripheral corner of the outer ring 5 collides with other articles, each of the corners has a high toughness metal spray coating. 8a, 8
b, the possibility that the corners of the inner ring 3 and the outer ring 5 are chipped is reduced.

Further, the inner race 3 is fitted to the outer peripheral surface of the rotating shaft.
And the outer peripheral surface of the outer ring 5 fitted inside the inner peripheral surface of the housing are covered with the metal spray coatings 8a and 8b. The fitting portion is not easily loosened, and creep is less likely to be generated on the fitting surface, so that the rolling bearing 1 is reliably supported on the rotating shaft and the housing.

FIG. 2 shows a second embodiment of the present invention. In the above-described first embodiment, the rolling elements 6 constituting the rolling bearing 1 together with the inner ring 3 and the outer ring 5 are balls, whereas in the present embodiment, the rolling elements 6 are rollers. Other configurations and operations are the same as those of the first embodiment.

[0023]

[Effect of the Invention] Since the ceramic race of the present invention is constructed and operates as described above, the production cost of the ceramic rolling bearing used for the high-temperature portion and the like can be reduced and the failure due to the defect after completion can be achieved. It is possible to reduce the non-defective product occurrence rate and to ensure the fitting support.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a first embodiment of the present invention.

FIG. 2 is a partial sectional view showing the second embodiment.

FIG. 3 is a perspective view showing an example of the entire configuration of the rolling bearing by cutting a part thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rolling bearing 2 Inner raceway 3 Inner race 3a Inner peripheral surface 3b End surface 4 Outer raceway 5 Outer race 5a Outer peripheral surface 5b End surface 6 Rolling element 7 Cage 8a Thermal spray coating 8b Thermal spray coating

Claims (1)

(57) [Scope of request for utility model registration] 1. A ceramic orbit formed entirely of ceramic in an annular shape and having a raceway surface formed on one circumferential surface, wherein a metal spray coating is formed on the other circumferential surface and an end surface, Ru finishing the surface of the sprayed coating to the desired dimensional accuracy
In addition, a ceramic bearing ring characterized in that the sprayed coating is left on the machined surface even after raising .