A hydraulically driven diaphragm pump with a diaphragm clamped at its edge between
a pump body and a pump cover separating a delivery chamber from a hydraulic chamber
and pretensioned in the direction of its intake stroke by spring force. A hydraulic
diaphragm drive in the form of an oscillating displacement piston is displaceable
in the pump body between a reservoir chamber for the hydraulic fluid and the hydraulic
chamber. The diaphragm is so strongly pretensioned by spring force that it exerts
a substantial compressive force on the hydraulic fluid in the hydraulic chamber.
Therefore a substantial hydrostatic pressure is built up in the hydraulic chamber
relative to the delivery chamber.
