Causes of motor bearing rust

The deep groove ball bearing often appears poor operation and increased noise used by the motor. It is found that the bearing has rusted under the microscope after removing the seals, cleaning and drying.

We will discuss the causes of motor bearing rust today:

(1) It will often appear, when the motor is placed in the warehouse where the humidity is relatively large and the temperature is relatively high in one week.

(2) Block rust often appears on the surface layer near the motor rotor side, and black spot-like rust often appears on the outer surface layer of bearings with serious conditions.

(3) Oil color changes, while there is a pungent paint odor.

(4) Rust spots loose and porous, very easy to fall off automatically for very serious cases.

This rusting phenomenon of motor bearings is very similar to the "lacquer rust" reported abroad.

The rust occurs frequently in sealed ball bearings for medium and small motors according to market feedback. Therefore, it is necessary to find out the root cause and take certain effective measures to prevent it.

Principle and characteristics of bearing paint rust:

Lacquer rust is affected by internal and external overall factors: motor stator insulation paint volatilized acid molecules and moisture together by grease absorption reaction caused.   This phenomenon is related to the type of insulating paint, the drying process of the stator and the storage environment of the motor.

The use of amino or phenolic insulating paint, paint in the hardening process of molecular chain instability will have low molecular substances escape:  such as formaldehyde, in the temperature and humidity of the appropriate time, formaldehyde and water molecules in the weather reaction to produce formic acid, formic acid will make grease hydrolysis, corrosion bearing paint rust.

Paint rust mainly often appears in enclosed motor or enclosed packaging placed motor.  This is mainly closed motor paint gas is not easy to escape the reason.  The characteristics of paint rust are as follows:  

Usually in the high temperature and high humidity of southern areas and high humidity of coastal areas.  In the muggy season, most of the motors are placed within 1 ~ 3 months after production, and some serious motors are placed 2-3 weeks after painting rust phenomenon;  Paint rust is generally manifested as normal noise during motor assembly test, and noise is unqualified after being placed for a period of time or sent to the customer for detection;  Lacquer rust phenomenon mostly appears in the case of solvent-based insulating paint, sometimes the use of solvent-free paint will also appear (insufficient drying time or drying temperature).

Kent Bearing is an enterprise focusing on the research and manufacture of ball bearings with high precision and low noise, and has rich experience in the production and sales of bearings. At present, our products are widely used in motor, automobile, household appliances, power tools, garden tools, fitness equipment, medical equipment, water pumps, mechanical equipment and other fields. We have been well received by many customers adhering to the business philosophy of "the real quality is more durable, so that the bearing rotation is quieter". Welcome to inquiry and feel free let me know if you any interesting.