| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce power consumption and noise of an electric oil pump.SOLUTION: A controller 24 controls an electric oil pump 22 in such a way that a driving torque of an electric oil pump 22 enabling hydraulic pressure required by a hydraulic element to be attained is set to a desired driving torque, an actual driving torque may become a desired driving torque and an actual rotational speed may become more than a lower limit rotational speed required for supplying hydraulic pressure required by the hydraulic element. A hydraulic pressure selection circuit 30 selects a higher value of a discharging pressure of a mechanical oil pump 21 and a discharging pressure of the electric oil pump 22 and supplies it to the hydraulic element. The controller 24 decreases the lower limit rotational speed to a waiting rotational speed lower than a rotational speed required for supplying hydraulic pressure required at the hydraulic pressure element as long as the rotational speed of the electric oil pump 22 is the lower limit rotational speed and the discharging pressure of the electric oil pump 22 is not selected by the hydraulic pressure selection circuit 30.</p> |
