Roller bearings — also calls rolling-element bearings — which are similar to ball bearings because they are also designed to carry loading when minimizing friction . The only difference is roller bearings transmit loads using cylinder rolling elements, not balls, to maintain the separation between moving parts of the bearing.
Ball bearing is a spherical unit that accomplishes the same objective as a roller bearing. The real difference has to do with the contact surface between the bearing and the rail .
For ball bearings (assuming a perfectly spherical bearing and no deformation), the contact surface is just a single point. Even once deformation is accounted for, the amount of surface where the ball is contacting the rail is limited. This creates an inherent strength limit for the balls. Roller bearings on the other hand, have an entire line of contact. This greatly increases the rigidity, stability, and maximum load capacity of the system.
WSBC bearing is the professional roller bearing manufacturer , can supply high quality roller bearings in variety roller bearings , if you interested , welcome you contact us freely .