Positive-displacement rotary pump

摘要

The pump has a stator (1) with a holder (6) and a baseplate (3) whose surface, towards the holder, contains an annular surface extending through part of a circle. An inlet (13) and outlet (15) are connected to the surface (5), which is covered by a membrane (11) whose edges are clamped between the holder and the baseplate. A pumping passage (12) from inlet to outlet is formed between the membrane and baseplate. A driven rotor (2) above the annular surface turns on the axis (4) of the latter, and has one or more rollers (21) locally depressing the membrane and running against individually-depressed transmission members (14), so that the membrane continuously interrupts the path between inlet and outlet. Where the annular surface joins the outlet, the stroke of the membrane is less than elsewhere in the pumping passage. The transmission members at this point can have a shorter stroke than the remainder, and the membrane can be permanently deflected by one of the members at this position.