Patent ID: 8042920

Claim:
A fluid supply apparatus comprising: a cylinder having a first supply/discharge opening and a second supply/discharge opening for supplying or discharging a fluid; a piston movably disposed in the cylinder, the piston forming a chamber with the cylinder; a rotating channel open/close unit movably disposed within the cylinder and configured to open or close a channel that communicates the first or the second supply/discharge opening with the chamber in the cylinder, wherein the rotating channel open/close unit closes at least one of the first and the second supply/discharge openings at any time; and a linking unit configured to link a rotation of the channel open/close unit and a movement of the piston, wherein the fluid is caused to enter the chamber via the first supply/discharge opening and exit via the second supply/discharge opening by the rotation of the channel open/close unit in one direction, and wherein the fluid is caused to enter the chamber via the second supply/discharge opening and exit the chamber via the first supply/discharge opening by the rotation of the channel open/close unit in another direction.