VEHICULAR MOTOR DRIVE DEVICE AND AUTOMOBILE

摘要

A vehicular motor drive device is provided with an electric motor and a speed reducer having two gear trains capable of switching a fixed gear ratio. Driving force curves, which are determined depending on an output characteristic of the motor and represent a relationship between an output rotation speed in the respective gear train and an output torque, which is obtainable maximally at such output rotation speed, have a constant torque curve section, a gradually decreasing torque curve section and a constant speed curve section. The gear trains have respective speed reduction ratios such that the driving force curve of a gear train having a larger speed reduction ratio and the driving force curve of a gear train having a smaller speed reduction ratio continue to and partially overlap with each other in the gradually decreasing torque curve sections.