Precision displacement non-contact hydraulic oil cylinder

The utility model discloses a precision displacement non-contact hydraulic oil cylinder which comprises a cylinder barrel, a piston rod which extends into the cylinder barrel through a cylinder cover, and a piston. A hollow hole channel is formed in the center of the piston rod, and a position magnet is installed at the end face of the piston rod. The position magnet is isolated from the piston rod through a non-magnetic gasket. A digital quantity sensor is installed at the bottom of the cylinder barrel, a displacement sensing rod is installed on the digital quantity sensor, the displacement sensing rod extends into the hollow hole channel so that the displacement sensing rod and the hollow hole channel can generate relative non-contact axial displacement along with moving of the piston. Compared with the prior art, an original contact sensor and an external displacement sensor are replaced by the internal non-contact sensor, the oil cylinder is installed in a non-friction mode, the non-contact position magnet is used for measuring the displacement of the oil cylinder, and the precision displacement non-contact hydraulic oil cylinder has the advantages of being simple in technology, accurate in displacement measuring and long in service life.