Patent ID: 6185956
Filing Date: 2001-02-13
Classification: F04C,F25B

Abstract:
A plural rotor displacement machine for expanding and compressing a refrigerant, said machine comprising:a first rotor having a plurality of helical lobes disposed about a rotor periphery;at least one second rotor in meshing contact with said first rotor and having a plurality of helical grooves disposed about at least one second rotor periphery for receiving the lobes of said first rotor during rotation of said rotors in opposite directions; anda housing defining a chamber enclosing the rotors and having an inlet port at one end and an outlet port at an opposite end;said housing including an intermediate port formed in a side wall of said chamber between the inlet port and the outlet port and wherein said rotors and said housing define during rotation of said first rotor in one direction an effectively closed expanding working chamber between the inlet and intermediate ports and an effectively closed contracting working chamber between the intermediate and outlet ports.