Patent ID: 7871250
Filing Date: 2011-01-18
Classification: F04B

Abstract:
1. A chemical liquid supplying apparatus comprising: a pump provided with an elastically deformable partition film for partitioning a drive chamber and a pump chamber communicating with a liquid inflow port and a liquid outflow port; a cylinder incorporating reciprocably, into the drive chamber, a piston for supplying/exhausting an incompressible medium to/from the drive chamber, the cylinder having a sliding face on which a sliding face of the piston slides; a driving means for reciprocating axially the piston to expand/contract the pump chamber via the incompressible medium; and an elastic deformable member provided between the piston and the cylinder and forming a seal chamber for enclosing the incompressible medium so as to be contiguous to the sliding face of the piston, the elastic deformable member being formed by a bellows cover, the average effective diameter of the bellows cover being set so as to be approximately equal to an outer diameter of the sliding face of the piston.