ELECTRICITY-MACHINE CONVERSION DEVICE

PURPOSE:To accurately convert an electrical signal into the amount of a mechanical operation by converting the imputted signal into a small displacement amount of the first movable member by means of a force motor, and also converting the operation amount of the piston moving by hydraulic pressure into a small displacement amount of the second movable member by means of a feedback mechanism, and then conducting control of working fluid of the piston fased on the difference between the above displacement amounts. CONSTITUTION:An electrical signal is inputted to a terminal 1a of a force motor 1, and its driving shaft 1b is displaced leftward, and further a spool 19 is displaced leftward to bring ports 31 and 32 into a condition of communication with each other. This causes pressurized fluid to flow from a port 31 into one introductory chamber 5 through a flow passage 28, and a piston 4 moves leftward. Energized by movement of the piston 4, a feedback rod 12 is rotated leftward, then a sleeve 18 is moved leftward in a manner like pursuing the spool 19. At a point of time when the port 31 is blocked up again by means of the spool 19, the piston 4 is stopped.