| 摘要 |
The present invention provides an apparatus for electrically and hydraulically driving a hydraulic cylinder, including a hydraulic pump rotatable in opposite directions, an electric motor for driving the hydraulic pump, a reservoir tank containing hydraulic fluid therein, and a servo-valve. The hydraulic cylinder makes fluid-communication at a head-sided hydraulic chamber with a first port of the hydraulic pump, and makes fluid-communication at a rod-sided hydraulic chamber with a second port of the hydraulic pump. The servo-valve allows ones of the head-sided hydraulic chamber and the rod-sided hydraulic chamber to make fluid-communication to the reservoir tank in accordance with a direction in which the hydraulic pump rotates, and varies a degree at which one of the head-sided hydraulic chamber and the rod-sided hydraulic chamber makes fluid-communication with the reservoir tank, to a designated degree. |
