Rotary compressor with communication between chambers to provide supercharging

A method of compressing fluid using a rotary fluid compressor including a housing defining a cavity therewithin having inlet and outlet ports, a rotor rotatable in said cavity, said rotor having a pair of opposed apexes wiping the wall of said cavity to divide the latter into a pair of chambers, an inlet port check valve for permitting fluid communication into said cavity but preventing communication of fluid from said cavity through said inlet port, an outlet port check valve for permitting fluid communication from said cavity but preventing fluid communication into said cavity through said outlet port, said method comprising the steps of communicating one of the chambers with the inlet port and the other chamber with the outlet port, rotating said rotor with both of said check valves open to compress the fluid in said other chamber until the rotor attains a dead-center position in which the volume of said other chamber is minimized and the volume of said one chamber is maximized, closing both of said check valves at substantially the same time as said rotor rotates past said dead-center position, opening a bypass passage around the tip of at least one of said apexes while said check valves are closed to permit communication between said chambers, and closing said bypass passage after the pressures in said chamber equalize.

In a rotary air compressor, a housing defining a cavity therewithin having a peripheral wall, an inlet port and an outlet port in said peripheral wall, a rotor rotatable in said cavity, said rotor having a pair of opposed apexes wiping said peripheral wall to divide said cavity into a pair of chambers, one of said chambers being communicated to said inlet port and the other chamber being communicated to the outlet port, said inlet and outlet ports being located in said peripheral wall such that the tip of each of said apexes wipes across one of said ports when the other apex wipes across the other of said ports, at least one of said inlet and outlet ports communicating with both of said chambers when the rotor is in a predetermined angular position in which said apexes wipe across the ports, an inlet port check valve permitting communication into said cavity through said inlet port but preventing communication in the reverse direction, and an outlet port check valve permitting communication from said cavity through said outlet port but preventing communication in the reverse direction, said inlet and outlet ports being located on said peripheral wall such that the pressure differentials across the check valves hold said check valves closed when the apexes of the rotor wipe across said ports.