Preparation And Performance Research Of Insulation Coating On Bearing Outer Ring

There is current across the bearing when the traction motor is using, the bearing appear pitting, and makes bearing surface damage seriously. So, insulation bearing is usually used in the traction motor, the insulation bearing is divided into four kinds, such as the whole bearing is insulation, the rolling is insulation, the inner and outer ring is insulation and the inner and outer ring with insulation coating. We decide to select the way of making insulation coating on the inner and outer ring by plasma spraying.This paper research the preparation process of insulation, summarize the pretreating on substrate before the spraying, in order to improve the bond strength between the coating and substrate, and gind and polishing the original coating surface, in order to reduce the roughness of the original coating. The analysis of microstructure and phase composition of coating, and micro hardness of substrate bear out that the organization of coating is compact,αAl2O3 is transformed toγAl2O3, the micro hardness of bearing outer ring is lower a little.In connection with the coating on the bearing outer ring, draw up the test method about the insulation performance, simulate the situation of coating in humid environment by neutral salt spray test, the test result proves the insulation performance of coating meets the requirement when the coating is dry, and its resistance would be reduced when it suffers cycle influencing thermal load.Draw up the test method of bond strength between the coating and substrate, include the tensile and yield strength test of coating, the test result proves that the yield strength of coating meets the requirement, but the tensile strength is a little weak, and the weakest place is the contact surface between the coating and substrate.According to the radiation situation of bearing, this paper examinates the thermal shock resistance of coating, the result bears out the coating don't appear cracking or flake when the coating suffers cycle influencing of thermal load, and the insulation performance also meets the requirement.This paper analyzed the reason of residual stresses in coating, summary the theory analysis model of residual stresses in coating, and calculates the distributed situation of residual stresses in coating by ansys, compares the magnitude and distributed situation of residual stresses in single coating, add the adhesive coating and the gradient coating.