To provide a motor-driven fan system for a vehicle improved in service life, while reducing unevenness of wind velocity distribution.
The motor-driven fan system for a vehicle is structured by arranging two motor-driven blowers, which circulate cooling air to a radiator and a capacitor, in parallel with each other in the vehicle width direction. Each of the motor-driven blowers is driven by a brushless motor and a motor with a brush. First driving voltage V1 for driving the brushless motor is set to be increased in response to increase of water temperature Tw of the radiator and coolant pressure Pc of the capacitor. At the same time, second driving voltage V2 for driving the motor with a brush is set to be lower than the first driving voltage and to be monotonously increased. With this structure, the two motor-driven blowers can be always rotated at the same time, and unevenness of wind velocity distribution can be reduced. Since the driving voltage for the motor with a brush is set to be low, service life can be improved.
ODA SHINICHI
Takahiro Miura
Fumihiro Mizuno