DIAPHRAGM PUMP

摘要

The invention relates to a diaphragm pump (1) for delivering and metering an especially liquid medium. Said pump comprises a delivery compartment which can be filled with a liquid medium, a pressure compartment, filled with a hydraulic liquid, a diaphragm (7) that separates the delivery compartment from the pressure compartment and that is fastened to freely oscillate between the two, a piston working compartment (16) provided in the pressure compartment and being fluidically connected to the diaphragm, and a hydraulic diaphragm drive having a piston (15) that can be longitudinally displaced in the direction of the diaphragm. Said piston interacts with the piston working compartment (16) with its lower face facing the diaphragm, the piston (15) being displaceable by a predetermined distance in the direction of the membrane. The piston working compartment (16) has a bottom surface (20) against which the piston (15) abuts with its lower face (34) during its movement inside the piston working compartment (16) so that the piston (15) reaches a lower dead point when contacting the bottom surface (20).