DIAPHRAGM PUMP Russian patent published in 2014 - IPC F04B43/02 

FIELD: engines and pumps.

SUBSTANCE: proposed pump comprises membrane head with two chambers composed by membrane with case and cover with membrane edge secured between flanges on the latter, and moving rod displacing relative to case and cover for membrane center part to be rigidly secured thereat. Membrane head is equipped with two pressure valves and two suction valves. Case with rod are furnished with two seal rings fitted in the case coaxial grooves spaced apart along rod axis and accumulation chamber arranged there between and separated by baffles. Said case has cylindrical chamber accommodating piston of the same diameter communicated via channel with accumulation vessel on the side facing said rod. The side opposite said rod is communicated via opening and check valve with one of the membrane head chambers. Accumulation chamber and part of cylindrical chamber communicated with the latter are filled with grease. Piston diameter D is defined by the formula: $$D\ge \sqrt{\frac{4\left(F_{mp}+F_c\right)}{\pi P}}$$ where D is piston diameter, F_mp is the force of piston friction against chamber wall; F_c is the force of adhesion of grease with chamber wall; P is pressure inside membrane head chamber.

EFFECT: longer life owing to additional lubing of moving rod seals.

2 dwg