Hydraulic power conversion device

A hydraulic power conversion device comprising:

• a main oil container having an inlet for supplementing hydraulic oil;
• a pair of hydraulic pumps connected to said main oil container;
• a motor drivingly connected with said hydraulic pumps;
• a twin-circuitry hydraulic cylinder mechanism including a first hydraulic cylinder, a first piston, a piston rod, a sealer, a second piston, a high pressure leakage proof packing and a second hydraulic cylinder, said first hydraulic cylinder having same length as said second hydraulic cylinder but having a smaller diameter than said second hydraulic cylinder, said first hydraulic cylinder being connected with said second hydraulic cylinder by screws, said sealer being fitted between said first and second hydraulic cylinders to form two regions, said second hydraulic cylinder having an inlet provided with a first check valve and an outlet provided with a second check valve;
• an oil retrieving container connected with said inlet of said second hydraulic cylinder;
• and
• a hydraulic pressure storage trough connected with said outlet of said second hydraulic cylinder;
• said hydraulic pressure storage trough being provided with a relief valve which is in turn connected with said oil retrieving container;
• each of said first and second check valves including a packing ring, a steel ball, and a spring urging said steel ball against said packing ring;
• a third hydraulic cylinder which has same stricture as said second hydraulic cylinder and arranged on another side of said first hydraulic cylinder.