Technical Information

Typical Bearing Materials and Temperature Limits - Many problems with bearing applications revolve around operating a standard bearing product in heat related applicatons. The typical bearing has been processed in a heat treatment cycle that provides dimensional control only up to 250°F or 300°F (121°C - 148°C). Bearing steel grows when heat is applied to it. It contracts to the original size, when cooled. Operating above the heat stabilization temperature may allow changes to the metallurgical structure, thus permanently deforming the product and limiting its ability to return to its original size. It also affects the hardness and operating clearances.

It is always important to examine the temperature limit of each component in a bearing. The component with the lowest temperature is the maximum limit at which the bearing can be operated at. As an example, the maximum temperature for a typical sealed bearing with nitrile rubber seals is 250°F(121°C). Therefore, a standard sealed bearing will not operate properly above 250°F(121°C). Don't forget to include the grease or oil temperature limits into your analysis.

Ceramic Hybrid Bearing Performance Advantages

• Higher Speeds
  • The low density of the silicon nitride balls reduces the load applied due to centrifugal forces, thereby allowing for increase operational speeds.
• Higher Stiffness
  • A 50% higher elastic modulus of silicon nitride over bearing steel results in a stiffer, more rigid bearing, which is advantageous to high precision machine tools.
• Reduce Heat Generation
  • Low frictional characteristics of the silicon nitride ball results in lower heat generation and lower operating temperatures.
• Thermal Stability
  • With thermal expansion being 1/3 that of steel, the silicon nitride ball reduces the effects of thermal gradiants across the bearing thus reducing the risk of bearing seizure.
• Corrosion Resistance
  • Excellent resistance to corrosive media allows for extended bearing life over standard steel balls. Corrosive solutions that enter the bearing cause the ball to deteriorate and corrode to the the raceway surfaces during static operation. Silicon nitride balls with their resistance to corrosion and high hardness levels allow for continued use and self healing of the deteriorated raceway surfaces.
• Non-Conductive
  • Silicon nitride is a nonconductive material thus reducing the potential of current flow through the bearing and the resulting electrical arcing or fluting damage that is associated with it.