Patent ID: 8044628

Claim:
A controller for a permanent magnet field motor comprising a first rotor and a second rotor concentrically provided around a rotating shaft and a phase changing device for changing an angle of relative displacement in a circumferential direction between the first rotor and the second rotor to serve as a power source for driving driven wheels of an all-wheel drive vehicle having two main driving wheels and at least two driven wheels, the controller comprising: a drive control portion to control driving of the motor according to a drive mode of the all-wheel drive vehicle; and a phase instruction portion to issue an instruction, when the drive mode of the all-wheel drive vehicle is a main-driving-wheel drive mode in which the all-wheel drive vehicle is driven only by the main driving wheels, to set the angle of relative displacement at an angle at which a magnetic flux generated at each of the first and second rotors is weakened, as compared with that generated at each of the first and second rotors in an all-wheel drive mode in which the all-wheel drive vehicle is driven by the main driving wheels and the drive wheels.