Development of Super-Low Friction Torque Tapered Roller Bearing for Improved Fuel Efficiency

To achieve high efficiency in rear axle differentials, the reduction in friction torque of the tapered roller bearings supporting the pinion was investigated. The effects of internal geometry, and oil flow within the bearing, on friction torque were clarified. The friction torque of a newly developed bearing optimized considering various performance characteristics was 70-75% lower than that of a conventional bearing. This is equivalent to a friction torque reduction of about 80% from that of a standard bearing. This is expected to have a remarkable effect on vehicle fuel efficiency.