The invention relates to an internal-drive internal indirect feedback type digital
hydraulic cylinder structure. The internal-drive internal indirect feedback type digital
hydraulic cylinder structurecomprises a cylinder body, a hollow
piston rod, a large-lead spiral body, a valve element, a valve body and a stepping motor; the hollow
piston rod is slidably mounted in the cylinder body, the valvebody is mounted on a cylinder body rear end cover and coaxially connected with the cylinder body, the valve element is arranged in the valve body, and one end of the valve element is coaxially and rotatably connected with the large-lead spiral body; the large-lead spiral body enters a hollow cavity of the hollow
piston rod through the cylinder body rear end cover and a cylinder rear cavity; a nutis fixedly mounted at the position, at an inlet of the large-lead spiral body, of the end of the hollow
piston rod, and the nut is engaged with the large-lead spiral body; and the other end of the valve element is fixedly connected with the output end of the stepping motor. The internal-drive internal indirect feedback type digital
hydraulic cylinder structure has the advantages that the hydraulic cylinder
stroke reaches 0.5-1.0 m or even more, the
operating speed is higher, and the price is lower relatively; and through structural optimization and the
layout design of the space position of oil holes, the valve structure becomes compact, and the overall structure size of a hydraulic cylinder is smaller under the situation that a certain
stroke is met.