Produce motor NSK bearing rust is very complicated, may be NSK import bearing rust treatment is not good, may also be water caused by rust, and by the paint mist caused by rust.

Most of the insulating paint used in the motor factory volatilised out of the acid components are mainly four kinds:
① low molecular paint raw material acid components did not react (anhydrous isophthalic and terephthalic acid, anhydrous cis-butenedioic acid, trans-butenedioic acid).
(ii) The acid component generated when the paint is cured (when using phenolic denaturing paint, the formaldehyde water becomes formic acid).
(iii) Low-grade fatty acids (formic acid and acetic acid) generated by heat or oxidative decomposition.
(iv) The acid component generated by the water decomposition of the paint curing material. The main acid component produced by insulating paint is formic acid, and there is a close relationship between the amount of formic acid and the degree of rust occurrence.
Lubricating grease adsorption of the paint volatilised out of the acidic components, causing deterioration of the grease, and this acidic components and promote the hydrolysis of the grease, the result is that the concentration of acidic components increases, causing NSK bearing corrosion.

The working principle of grease is to use the grease layer to separate the steel ball from the inner and outer raceway, using the viscosity characteristics of the grease, adhering to the steel ball and raceway surface, separating the steel ball and the inner and outer raceway of the metal interface to reduce the wear and tear of the metal surface and to protect the metal from the corrosion of the air and water, reduce vibration and noise, so that NSK bearings can rotate smoothly.
But after the deterioration of grease, viscosity will change, the oil film broken through, grease separation function and adhesion characteristics will disappear, so the consequences.

One is to make the acidic components produced by the insulating varnish directly oxidised metal surfaces, causing bearing corrosion.
The second is to cause the steel ball and the inner and outer raceway direct contact contact, rotating wear, thus causing noise increase.