| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a vehicular motor drive device that enables smooth acceleration and high-speed travel, comfortable traveling, and highly efficient motor drive through optimal gear selection even with a small motor without causing an abrupt torque change when switching between speed reduction ratios. <P>SOLUTION: This device includes an electric motor 10, and a speed reducer 20 with two gear trains 23, 24 that enable switching between fixed gear ratios. For each of the gear trains 23, 24, drive power curves L1, L2, indicating the relationship between an output rotation speed and a maximum output torque obtained at the output rotation speed, as determined by the output characteristics of the electric motor 10, both have constant-torque curve sections L1a, L2a, gradually decreasing-torque curve sections L1b, L2b, and constant-speed curve sections L1c, L2c. Each of the gear trains 23, 24 has the speed reduction ratios such that the drive power curves L1, L2 of both the gear trains 23, 24 are contiguous with an overlap section Lba in the gradually decreasing-torque curve sections L1b, L2b. <P>COPYRIGHT: (C)2013,JPO&INPIT |
