A cylinder driving system capable of reducing the number of hydraulic devices
and
the amount of energy loss and an energy regenerating method thereof are provided.
To this end, the system includes i) a hydraulic cylinder, ii) a hydraulic pump
having three suction/discharge ports of a first port for supplying oil to a bottom
chamber of the hydraulic cylinder or draining oil from the bottom chamber, a second
port for draining oil from a head chamber of the hydraulic cylinder or supplying
oil to the head chamber, and a third port for draining oil from a tank or supplying
oil to the tank, the suction rate or the discharge rate in the first port being
the sum of the respective discharge rates or suction rates in the second port and
the third port, and iii) a driving source for driving the hydraulic pump.
