NSK recently developed a series of new ceramic coated bearings. These ceramic coated bearings play an insulating role which used in inverter motor which , and is suitable for all general industrial machinery. The purpose of designing these insulated bearings is to help support the ever-expanding application of inverter-controlled motors, which are becoming more popular as factory power costs decrease. All common mechanical parts will all benefit from this new development, including pumps, compressors and fan.
The key to ceramic-coated bearings is that the motors currently used with frequency converter speed control are expanding. However the bearings used for such applications are susceptible to certain types of damage known as galvanic corrosion. When current passes through the contact points of the bearing race and the rolling element during rotation of the bearing, a spark is created in the thin lubricant film causing the surface to locally melt into an irregular shape. One way to prevent galvanic corrosion is to use non-conductive ceramic balls in the bearings. However, this may have a negative impact on productivity. Another option is to have an insulating housing in the motor, but this requires special parts and assembly processes. To overcome these problems, NSK has developed a new ceramic coated bearing that is insulated, highly productive and compatible with all standard inverter controlled motors.
Aluminum ceramic materials are used to coat the outer surface of the outer ring, and the insulation properties are typically increased by about 10 times by combining optimized additives. In addition, the coating has excellent heat dissipation, while durability is also enhanced compared to ordinary bearing components, film impact resistance increased by three times. NSK offers ceramic coatings in deep groove ball bearings and cylindrical roller bearing series, including 50 to 110 mm bearing bore diameters.