Patent ID: 8047814
Filing Date: 2011-11-01
Classification: F04B

Abstract:
1. A chemical liquid supplying apparatus comprising: a pump provided with an elastically deformable partition membrane for partitioning a pump chamber and a driving chamber, the pump chamber communicating with a liquid inflow port and a liquid outflow port, and the driving chamber filled with a first quantity of incompressible medium for expanding and contracting the deformable partition membrane to pump chemical liquid from the liquid inflow port to the liquid outflow port; a cylinder assembly having an outlet fluidly connected with the driving chamber, and having a piston reciprocally mounted in the cylinder for supplying a second quantity of incompressible medium from the cylinder to the driving chamber to contract the deformable partition membrane and for exhausting the second quantity of incompressible medium from the driving chamber to the cylinder to expand the deformable partition membrane; driving means for reciprocating the piston to expand and contract the pump chamber via the incompressible medium; and a diaphragm, which has an elastically deformable portion provided between the piston and the cylinder having an axially reversibly deformable hemi-toroidal shape and forming a seal space continuous with a sliding portion between an outer peripheral face of the piston and an inner peripheral face of the cylinder, a third quantity of incompressible medium being enclosed in the seal space, wherein the elastically deformable portion stretches to absorb a volume change of the seal space caused by leakage of the incompressible medium between the piston and the cylinder.