PISTON COMPRESSOR Russian patent published in 2000 - IPC

FIELD: gaseous medium compression or vacuum generation. SUBSTANCE: inlet and outlet ports of cylinder are connected to suction and delivery valves. Piston rise to upper dead center forms dead space of cylinder under it whose effect should be reduced. Inlet ports of suction valves are axially arranged on cylinder section so that their upper edge is level with or close to butt-end edge of piston when it is at point where gas coming from volume dead space expands to suction pressure value. Additional ports are made at cylinder section in axial direction above or below butt-end edge of piston in its lower dead center which directly communicate with suction chamber. Transfer channel is made in piston to provide communication between inlet ports of suction valves and additional ports as piston approaches upper dead center. EFFECT: improved capacity and higher vacuum due to reduced effect of cylinder dead volume. 3 cl, 5 dwg