The Use of Cold Spraying and Micro-Arc Oxidation Techniques for the Repairing and Wear Resistance Improvement of Motor Electric Bearing Shields

Abstract

Reliability is one of the most important requirements for electric motor installations. Bearing assembly is a common source of failure for most electric motors. One of the main reasons for such failures is the wear of the bearing seat of the end shield. This paper presents a combined technology for increasing the durability of the bearing bores of electric motor bearing shields made of aluminum alloys. The technological concept is that a worn-out end-shield bore is firstly restored by supersonic gas-dynamic spraying, and secondly, in order to improve anti-wear properties, it is strengthened by micro-arc oxidation. The adhesion of coatings has been studied, and the wear resistance of the formed coatings has been evaluated. Based on the performed studies, it can be assumed that the service life of the bearing assembly of an electric motor restored by gas-dynamic spraying with the novel technology of micro-arc oxidation in real operating conditions will increase on average by 3–4 times. The developed technology is recommended for repair, maintenance, or other technical services dealing with the restoration and hardening of worn-out parts.