The permissible speed of a bearing depends on the frictional heat generated by the bearing, any externally applied heat and the amount of heat that can be transferred away from the bearing. In applications where heat dissipation is not adequate, either because of design considerations or high ambient temperatures, additional cooling methods might be needed in order to keep bearing temperatures within a permissible range.
Cooling can be accomplished through different lubrication methods. In oil jet and circulating oil systems, for example, the oil is filtered and, if required, cooled before being returned to the bearing.
The product tables list attainable speeds, but not speed limits, because the permissible speed is influenced by factors other than the bearing.