Corrosion principle of motor bearing is analyzed

Causes of motor bearing rust is complex, may be bearing anti-rust treatment is bad, can also be caused by moisture corrosion, and corrosion caused by the mist. Its type, bearing grease pre-filled with insulating paint, motor paint processing method and takes care of the environment, have a close relationship. For example, through analysis of a batch of corrosion inspection of motor bearing, determine the corrosion is the inside of the motor stator line package insulating paint of volatile corrosive acid composition with moisture is absorbed by grease, the grease deterioration failure, especially in the steel ball and raceway contact position, corrosion is more serious. Most used electric insulating paint, volatile acid composition mainly has four kinds: 1) Did not react low molecular paint raw materials acid ( Anhydrous ethanol and terephthalic acid, anhydrous maleic acid, trans butylene acid) 。 2) Paint curing generated when acid composition, Phenolic resin modified with the lacquer, the formaldehyde water into formic acid) 。 3) Low-level fatty acids (generated heated or oxidative decomposition Formic acid, acetic acid) 。 4) Paint curing water decomposition generated after acid composition. Insulating paint produce formic acid is the main acid composition, the number of formic acid has a close relationship with degree of corrosion occurs. Grease adsorption evaporates acidic constituents of the paint cause metamorphism, grease and the acidic component and promote the hydrolysis of oils and fats, acid concentration increased as a result, cause bearing corrosion. The working principle of the grease, is the use of oil layer of steel ball is separated from the internal and external raceway, using viscosity properties of oils and fats, attached to the surface of steel ball and raceway, separating the metal interface of ball and the inner and outer raceway, reduces wear on the metal surface and protect metal from air and water corrosion, reduce the vibration and noise, make the bearing can turn flexibly. But after grease metamorphism, viscosity will change, oil film wear, the separation function and adhesion properties of the grease will disappear, such consequences, one is made of insulating varnish acid composition, direct oxidation of metal surface cause bearing corrosion; 2 it is to cause the steel ball in contact with the inner and outer raceway straight touch, wear and tear occurs when revolving that cause noise increases.