Patent ID: 7841842
Filing Date: 2010-11-30
Classification: F04B

Abstract:
1. A chemical liquid supplying apparatus comprising: a pump provided with an elastically deformable partition film for partitioning a pump-side drive chamber and a pump chamber communicating with a liquid inflow port and a liquid outflow port; a cylinder connected to the pump, a large-diameter cylinder hole and a small-diameter cylinder hole being formed in the cylinder; a piston having a large-diameter piston portion fitted into the large-diameter cylinder hole and a small-diameter piston portion fitted into the small-diameter cylinder hole, mounted axially reciprocably inside the cylinder, forming in the cylinder a piston-side drive chamber communicating with the pump-side drive chamber, and supplying/exhausting an incompressible medium to/from the pump-side drive chamber; a bellows cover provided between, and coupled to, the large-diameter piston portion and the cylinder, and forming a first seal chamber continuous to a sliding face of the large-diameter piston portion; an elastic deformable member provided between, and coupled to, the small-diameter piston portion and the cylinder, and forming a second seal chamber continuous to a sliding face of the small-diameter piston portion, the second seal chamber communicating with the first seal chamber; the incompressible medium enclosed in the first and second seal chambers; a drive means for axially reciprocating the piston to expand/contract the pump chamber by moving the incompressible medium in the piston-side drive chamber and the pump-side drive chamber; and a pressure detecting means for detecting pressure in at least one of the seal chamber and the drive chamber.