F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
F04C14/18—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber
F04C14/22—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members