Grease the working principle is to use the oil layer and the inner and outer ball raceway separated by oil viscosity characteristics, attached to the ball and raceway surface, separating the ball rolling metal interface with internal and external channels, reducing the metal surface wear and protect the metal from air and water erosion, reduce vibration and noise, the bearing can rotate smoothly. But the deterioration of grease, the viscosity will change, the film broke through, grease separator function and adhesion properties will disappear, the consequences produced. First, make varnish produces acidic components direct oxidation of the metal surface, causing bearing corrosion. Second, causing the ball inside and outside the raceway directly touch, abrasion occurs when rotated, causing the noise increases. Insulating paint out of the volatile acid ingredient used in most of the electrical plant, there are four:
Low molecular weight materials paint
① unreacted acid composition of (anhydrous iso phthalic and terephthalic acid, anhydrous maleic acid, fumaric acid).
②paint curing acid components generated (when using the modified phenolic paint, formaldehyde water into formic acid).
③ thermal or oxidative decomposition of lower fatty acids (formic acid, acetic acid).
Acid composition of the cured paint
④ after hydrolysis generates. The main acid component varnish produced are formic acid, there is a close relationship between the occurrence of the amount of formic acid and the extent of corrosion occurring.
Adsorption grease paint out of the volatile acidic components, causing grease deterioration, and this acidic ingredient also promote hydrolysis of fat, resulting in an increase in the concentration of acidic components, causing bearing corrosion.