Oil pump driving device for transmission

An oil pump driving device for driving an oil pump combined with a transmission coupled to an engine for supplying working oil to lubricate the transmission and to make gear shifts, said oil pump driving device comprising:

• an electric motor adapted to be mounted on the transmission;
• a first power transmitting path for connecting an output shaft of said electric motor to a drive shaft of the oil pump;
• a second power transmitting path for connecting an output shaft of the engine to the drive shaft of the oil pump;
• motor control means for variably controlling the rotational speed of said electric motor;
• said motor control means comprising means for rotating said electric motor at a speed corresponding to a predetermined speed of the engine when the rotational speed of the engine is lower than a predetermined speed;
• said motor control means further comprising means for de-energizing said electric motor when the rotational speed of the engine is higher than said predetermined speed;
• drive selection means for selecting one of said first and second power transmitting paths at a time;
• said drive selection means comprising means for selecting said first power transmitting path when the rotational speed of the engine is lower than said predetermined speed;
• said drive selection means further comprising means for selecting said second power transmitting path when the rotational speed of the engine is higher than said predetermined speed;
• and
• wherein said motor control means variably determines said predetermined speed based on the amount of working oil required by an operating condition of the transmission.