JPH01112026A - Bearing - Google Patents

Abstract

PURPOSE:To obtain a bearing with advantages of both metal and ceramics by applying thermal spray of ceramics on the surfaces in contact with balls or rollers, polishing the surfaces and constituting balls or rollers with ceramics. CONSTITUTION:Ceramics layers 11, 21, 42 subjected to thermal spray of ceramics and polishing are arranged on the surfaces where an inner race 1, an outer race 2, a retainer 4 made of metal come in contact with a ball 3. Consequently, contact takes place between ceramics materials themselves and the wear of the surface is decreased extremely down to a level same as the level of a bearing using ceramics in its entire parts. While, as the parts except balls 3 are made of metal substantially and big elastic deformation and thermal expansion of metal can be utilized in its assembly, its assembly is carried out by push fit or shrinkage/expansion fit. Therefore, the bearing with the advantages of both metal and ceramics can be obtained.

Description

[Detailed description of the invention]

1 skin five times upright

[Industrial application field]

The present invention relates to improvements in bearings including ball bearings and roller bearings.

[Conventional technology]

Bearings that support rotating bodies are conventionally made of steel, and their basic components are an inner ring, an outer ring, and a plurality of balls or rollers as rolling elements arranged between the two.
and a retainer for holding these rolling elements in a fixed position. In recent years, with advances in fine ceramics technology, various attempts have been made to use ceramics as materials for bearings. Ceramics are generally suitable as bearing materials because they have excellent wear resistance, and they also have high heat resistance and chemical resistance, so they can withstand harsh usage conditions. When using ceramics as a bearing material, one problem is strength, especially toughness, and the other problem is the difficulty of assembling the bearing. Although the former problem has been largely overcome through technological advances, ceramics have not yet reached the level where they can rival metals. The problem arises from the physical properties of the material, as the amount of elastic deformation and degree of thermal expansion of ceramics is smaller than that of metals, so bearings cannot be made using conventional assembly methods. In order to avoid this, it is necessary to give the bearing components a special shape, which places restrictions on the shape of the bearing and also affects the cost.

[Problems to be solved by the invention]

The purpose of the present invention is to solve the technical problems of bearings using ceramics as described above, and to create a bearing that combines a metal with no concerns about mechanical strength and ceramics, and takes advantage of the advantages of both. Our goal is to provide the following. Composition of the invention

[Means for Solving the Problems] The bearing of the present invention includes an inner ring 1, an outer ring 2, a plurality of balls 3 or rollers disposed between the two, and as illustrated in FIGS. 1 and 2. Those retainers-4
In the bearing composed of
As shown in the figure, the inner ring 1, the outer ring 2I3, and the retainer 4 are made of metal, and the surfaces in contact with the balls or rollers are sprayed and polished with ceramics, and the balls 3 or rollers are made of ceramics. It is characterized by In FIG. 3, parts indicated by numerals 11 and 21 are metal inner and outer rings, and parts 12 and 22 are layers coated with ceramics and polished. Similarly, in FIG. 4, reference numeral 41 is a retainer made of a metal plate, and 42 is a ceramic sprayed and polished layer provided on the surface thereof. The material of the metal parts is arbitrary, but conventional structural steel will usually be suitable. Depending on the application, AJ like duralumin! alloy, stainless steel, or N1 alloy,
Other materials such as MO alloys may also be used. Any ceramic may be used as long as it is strong and suitable for thermal spraying, including AN 203 and Zr 02. S! 3N4 is preferred. Thermal spraying and polishing may be performed according to known techniques. The appropriate thickness of the ceramic layer is 10 to 200 μm after polishing. [Function] Needless to say, the ceramic ball 3 (or roller) has much higher wear resistance than metal. However, when this is used in combination with a metal inner ring, outer ring, and retainer, the metal parts wear out significantly.
Bearings become a problem with low durability. According to the present invention, by providing a sprayed and polished layer of ceramics on the surfaces of metal parts that come into contact with the balls or rollers, the rolling contact between the ceramics is achieved, so wear on the surfaces is significantly reduced, and all parts are It will be on the same level as bearings using ceramics. On the other hand, when assembling, the parts other than the ball are essentially made of metal, and metal's large elastic deformation and thermal expansion can be utilized, so assembly is performed by push-fitting, shrink-fitting, or cold-shrinking. can. [Example] A ball bearing having the structure shown in the drawings was manufactured according to the following specifications. Inner ring Inner diameter 25M, height 15 feet, steel outer ring
Inner diameter 52 m, height 15 m, steel retainer press-molded steel plate x 2 pieces, riveted balls 8 m x 8 pieces, ZrO2 inner ring, outer ring, and inner surface of the ball pocket of the retainer are Zr
02 was thermally sprayed and polished to provide a ceramic layer with a finished thickness of approximately 100 μm. Since the bearing of the present invention is essentially made of metal except for rolling elements such as balls and rollers, it is equivalent to conventional bearings in terms of mechanical properties such as strength and toughness. level, and its assembly can be done using conventional methods. On the other hand, since the rolling elements are made of ceramics and the surfaces that come into contact with those of other parts have a ceramic layer,
The bearing of the present invention has the same performance as a ceramic bearing in terms of wear resistance.

[Brief explanation of the drawing]

1 and 2 show an example of the bearing of the present invention, with FIG. 1 being a plan view and FIG. 2 being a longitudinal sectional view passing through the shaft. Figure 3 is an enlarged view of the main parts of Figure 2, and Figure 4 is an enlarged view of the main parts of Figure 2.
It is a sectional view of the II direction in a figure. 1... Inner ring 2... Outer ring 3... Ball 4... Retainer 11.21.41... Ceramic layer Patent applicant Hisao Kobayashi Agent Takeshige Imai Patent attorney Souo Suga Summary 1 Figure 2 t! 1 Figure 3 Figure 4

Claims (3)

[Claims] (1) A bearing consisting of an inner ring, an outer ring, a plurality of balls or rollers placed between the two, and their retainer, where the inner ring, outer ring, and retainer are made of metal and come into contact with the balls or rollers. It is made by spraying ceramics on the surface and polishing it.
A bearing characterized in that the balls or rollers are made of ceramics. (2) The bearing according to claim 1, wherein the metal is structural steel. (3) The bearing according to claim 1, wherein the ceramic is selected from AL_2O_3, ZrO_2 and Si_3N_4.