Tribology Related to Power Transmission Devices for Electric Vehicles

Abstract

Electric vehicles do not require any clutch, torque convertor or multi-speed transmission, and their powertrain can be designed with a simple combination of an electric motor and a constant gear ratio reducer. High rotational speed of motors causes issues of noise, vibration and tribology. Countermeasures on gear tooth and surface finish design, lubrication and cooling system including oil characteristics, and design of bearings and oil seals are explained.