Hydraulic jacks’ hydraulic pump is driven by human or electric power, through the hydraulic system transmission, with the cylinder or piston as the top pieces. Hydraulic jacks can be divided into integral and separate type. Integral pump and hydraulic cylinder combine into one; separate pump and hydraulic cylinder separate, in middle with high pressure hose associated. The structure of Hydraulic Jack is compact, can steadily lift the weight, its maximum weight has reached 1,000 tons, travel 1 meter, transmission efficiency is high, so the application is wider. But it is easy to leak, not long-term support heavy objects. If needing long-term support we could use self-locking top. Screw jack and hydraulic jack to further reduce the height of the shape or increase the distance, can be made into multi-level telescopic.
