Corrosion Analysis and Solution of Motor Bearing

Motor manufacturers that are bearing the production of bearing quality and rust treatment problems, they find our bearing product quality inspection station, asked to test the quality of bearings and to help them solve the problem of motor bearing rust.
2 motor bearing sample corrosion accident characteristics
Through the understanding of the production and sales of several motor manufacturing plants, the production environment, the composition of the insulating paint used, the composition of the grease, the assembly process, the packaging materials, the storage of the warehouses and the production and sales of the motor parts and bearing production plants Site investigation and found that the corrosion accident has the following characteristics:
(1) mainly occurs in the ventilation fan, cold fan motor and other household appliances and office machinery, the machinery used by the motor power in the number of watts to several hundred watts, and is basically a closed small motor.
(2) the finished product is not found when the operation of a single motor assembly after the assembly, after a few months after the use of noise will increase the phenomenon. After the motor is disassembled, it is found that the noise is caused by the rust generated inside the bearing.
(3) corrosion of the motor bearing is in the manufacturing process or in the warehouse during storage, just the temperature is higher, the humidity of the annual 3/4 months.
(4) motor factory bearings are generally purchased directly from the bearing factory, the motor factory to buy back by the bearing factory through the rust-proof bearings, self-injection of grease, and then installed on the motor rotor. Most of the grease used in the grease is added in the lithium base oil, the use of solvent-based paint prone to paint rust accident.
(5) the internal bearing is sometimes more serious than the external corrosion, the corrosion and grease types and relative humidity, ester oil grease in the humidity (70% RH), coated with grease parts rust; Water-induced corrosion, in the absence of grease coated on the outer surface of the bearing easy to rust.
(6) Grease with a special paint smell, because the grease has deteriorated.
(7) The corrosion of the bearing has a clear direction, that is, the side of the bearing facing the motor side of the side of the corrosion occurred in the bearing, near the rotor side of the raceway surface and the cage more rust.
3 Motor bearing corrosion analysis
3.1 Corrosion principle
The reason for rusting the motor bearing is complicated, it may be that the rust treatment of the bearing is not good, it may be corrosion caused by moisture, and corrosion caused by paint mist. It is closely related to the type of insulating paint, the prefilled grease of the bearing, the handling method of the motor paint and the storage environment of the motor. Through the test of the corrosion of the motor bearing samples to determine the corrosion of the motor bearing is the stator inside the stator line insulation paint the volatile acid components and moisture together with the grease absorption, resulting in deterioration of grease deterioration Caused, especially in the ball and raceway contact position, corrosion is more serious.