With the background of social trends toward energy saving and advances in motor technology, drivetrains for vehicles such as automobiles have been electrified. Generally speaking, the output torque of a motor used as a prime mover with respect to the torque required for the product is small in many cases, so drive systems that combine a motor and a gear unit are often used to amplify the motor torque. Since these drive systems are required to be small and lightweight and to be very quiet, the gear unit must be improved in terms of the load capability and must have its vibration and noise reduced. It was difficult for conventional tooth surface modification design method to simultaneously improve the load capability and reduce vibration and noise. In this study, however, we made this possible by applying a shape representation method using principal component analysis to tooth surface modification design. This report describes an overview of the method and the results of the effectiveness verification.
