JPH0552223A - Electrocorrosion preventive rolling bearing - Google Patents

Abstract

PURPOSE:To keep high insulation performance of a hole-sealing treatment layer formed on a flame coating layer even if water enters or temperature rises, in case that the flame coating film made of insulation body is formed on an outer surface of a bearing ring of a rolling bearing so as to prevent, electrocorrosion. CONSTITUTION:A hole-sealing treatment layer 9 made of an insulation resin with good impregration performance and a hole-sealing treatment layer 10 made of an insulation resin with incomplete impregnation performance are combined, and the resultant layer is formed on a flame coating film 7. The holes on a surface is thus sealed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing used as a motor bearing or an axle bearing of a railway vehicle.

[0002]

2. Description of the Related Art In a rolling bearing used as a motor bearing of a railroad vehicle, the current of the motor flows through the rolling bearing when the grounding current collector of the vehicle is incomplete.
At this time, electric discharge may occur between the bearing rolling element and the outer ring rolling surface or between the inner ring rolling surface, and electrolytic corrosion may occur in the discharged portion.

In order to prevent such electrolytic corrosion, it has been conventionally known that forming a thermal spray coating of an insulating material such as ceramics on the outer surface of the bearing ring is an effective means. Further, in order to prevent a conductive material such as water from penetrating into the pores in the thermal spray coating by causing cracks in the thermal spray coating, it is possible to impregnate the pores of the thermal spray coating with a synthetic resin and perform a sealing treatment. It is known (Japanese Utility Model Publication No. 60-85626).

[0004]

When an insulating resin having low viscosity and good permeability such as methacrylic acid ester resin is used as the synthetic resin used for the above-mentioned sealing treatment,
Insulation resistance decreases due to infiltration of water and temperature rise, and there is a problem that prevention of electrolytic corrosion is incomplete.

When an insulating resin having a high viscosity and imperfect permeability such as an epoxy resin is used, there is a problem that the insulation resistance is lowered by the temperature rise, but the insulation resistance is hardly lowered by the infiltration of water.

[0006] Therefore, it is an object of the present invention to provide an electrolytic corrosion-preventing rolling bearing which can eliminate the effects of moisture infiltration and temperature rise when a thermal spray coating is subjected to sealing treatment, and can maintain high insulation performance. To do.

[0007]

In order to solve the above-mentioned problems, the present invention provides an electrolytic corrosion-preventive rolling bearing in which a sprayed coating of an insulating material such as ceramics is formed on the outer surface of a bearing ring. The sealing layer is formed by forming a combination layer of a sealing treatment layer made of an insulating resin having a good permeability and an insulating resin sealing treatment layer having a poor permeability.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, an electrolytic corrosion-preventing rolling bearing of the present invention is one in which a large number of rollers 4 held by a cage 3 are interposed between an inner ring 1 and an outer ring 2. The outer ring 2 is housed in the bearing box 5, and the shaft 6 is fixed to the inner diameter of the inner ring 1.

On the outer surface of the outer ring 2, there is a sprayed coating 7 formed by spraying an electrically insulating ceramic such as alumina, gray alumina or zirconia.
This thermal spray coating 7 itself is porous, and its pores 8 (see FIG.
Insulating resin is used to seal (see).

In the case of the present invention, as the insulating resin used for sealing, an insulating resin having good permeability (for example, methacrylic acid ester resin) and an insulating resin having incomplete permeability (for example, epoxy resin) are used in combination. For example, as shown in FIG. 2, the method of combining the two is such that the sealing treatment layer 9 made of an insulating resin having good permeability is formed as a lower layer, and the sealing treatment layer 10 made of an insulating resin having incomplete permeability is formed thereon. Or
Alternatively, as shown in FIG. 3, there is a method of turning upside down.

Further, any of the sealing treatment layers 9 and 10 is not limited to one treatment, but may be performed twice, and one sealing treatment layer 9 (or 10) is treated twice and the other treatment is performed. A combination of performing the treatment once for the sealing treatment layer 10 (or 9) is also possible.

In the case of the outer ring rotating type rolling bearing,
The thermal sprayed coating 7 having the sealing layer as described above is the inner ring 1
Formed on the outer surface of the.

In both the inner ring rotation and the outer ring rotation, similar treatment layers may be formed on the outer surfaces of both the inner ring 1 and the outer ring 2.

[Experimental Example] A ceramic bearing coating having a thickness of 0.5 mm was formed and sealed with a methacrylic ester resin twice and then with an epoxy resin. The result of measuring the temperature dependence of resistance is shown in FIG. Curves A and B in FIG. 4 are comparative examples, and curve C is the case of the present invention. Curve A shows the case where only silica resin is used as the sealing agent, and curve B shows the case where only epoxy resin is used.

[0015]

As described above, according to the present invention, since the insulating resin which is not completely permeable prevents the infiltration of moisture, it is possible to avoid the reduction of the insulation resistance due to the infiltration of moisture. As for the insulation resistance due to temperature rise, the combination of an insulating resin having good permeability and an insulating resin having imperfect permeability can significantly reduce the decrease in insulation resistance due to temperature rise.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view of an embodiment.

FIG. 2 is a schematic cross-sectional view of the sealing portion of the above.

FIG. 3 is a schematic cross-sectional view of the sealing portion of the above.

FIG. 4 is a graph of experimental results of temperature dependence of insulation resistance.

[Explanation of Codes] 1 Inner ring 2 Outer ring 3 Cage 4 Roller 5 Bearing box 6 Shaft 7 Thermal spray coating 8 Pore 9 Sealing layer 10 Sealing layer

Claims (1)

[Claims] 1. An electrolytic corrosion-preventing rolling bearing in which a sprayed coating of an insulating material such as ceramics is formed on the outer surface of a bearing ring, wherein the sprayed coating has a sealing treatment layer made of an insulating resin having good permeability and An electrolytic corrosion-prevention type rolling bearing characterized in that it is sealed by forming a combination layer with a sealing treatment layer made of an imperfect insulating resin.