Reciprocating pump with no crank - has hollow piston element driven by eccentric disc rotated by internal planetary gearing

摘要

The pump drive system is for pumps handling liquids or gases or producing a vacuum, and produces reciprocating movement of the piston element without the need for a crank housing. This is achieved by driving the sliding hollow piston element by means of a rotating eccentric disc inside this element. The disc has internal gear teeth engaged by planetary gear wheels driven by the pump shaft. Valving is provided by spring biassed ball valves in the inlet and outlet ports. The eccentric movement of the drive is converted to reciprocate by use of idler planetary gears.