Hybrid Ceramic Ball Bearings
Hybrid Bearings have steel rings and ceramic balls. Si3N4 Ball is the most popular for the balls as it has only 40 percent of the density of bearing steel but is much harder giving greater wear resistance. Zirconia is heavier with 75 percent of the density of steel so is less suitable for hybrid bearings. Hybrid bearings are also capable of higher speeds. Sometimes, excessive claims are made about the high speed capabilities of hybrid bearings. They can run faster than all steel bearings due to the lower centrifugal force generated by the ceramic balls but this is partially counteracted by the lower elasticity of the balls. As the balls are harder, the contact area between the balls and the raceway is smaller which causes a higher contact pressure. Under load, this can cause the raceways to wear faster than they would with steel balls. The speed increase for hybrid bearings is approximately 30 percent with adequate lubrication. Hybrid bearings can also operate better with limited lubrication as the lower friction material generates less heat but running speed should be reduced. Hybrid bearings are also less subject to ball skidding under initial acceleration due to the lower ball density.
Sinoma hybrid ceramic balls bearings are featured with:
1) High precision bearings, P4, P5 and P6.
2) Rings are made of refined chrome steel and stainless steel
3) Cage: PEEK & PTFE --can assure constant working under 250 centigrade--and peek cage is the ideal cage for the high speed as it can provide the lubrication during bearing working, and it has the property of self-lubrications. However for normal applications, steel cage and Nylon cage are enough.
4) Balls: Sinoma uses G5 Si3N4 balls for high speed bearings
5) Radial clearance: Normal C0, or C3.
6) Not only characterized by high speed, Sinoma hybrid ceramic ball bearings also have insulation functions. Hence for the small size of bore dia. 40mm, also can be used for the insulation bearing purpose.