In a roller bearing, where do the rollers roll?

• A. Outer Race
• B. Inner Race
• C. Cage
• D. Lubricant Film

Answer: (B)

Rolling elements transmit load by rolling on raceways. In a typical radial roller bearing, the inner race is the moving surface attached to the shaft, so the rollers roll along its raceway as the shaft turns, carrying the load and transferring motion. The outer race provides the fixed opposing surface and keeps the rollers aligned, while a lubricant film keeps the surfaces separated to enable smooth rolling rather than sliding.