Patent ID: 7309220

Claim:
A back pressure apparatus for orbiting vane compressors, comprising: an inlet port provided at a predetermined position on a circumferential portion of a cylinder and configured for allowing refrigerant gas to be introduced into the cylinder through the inlet port; an annular space defined between an inner ring and an inner wall of the cylinder; an orbiting vane disposed in the annular space of the cylinder for compressing the refrigerant gas introduced into the cylinder and for discharging the compressed refrigerant gas from the cylinder, the orbiting vane having a vane plate and a circular vane integrally formed at an upper part of the vane plate; and a back pressure mechanism disposed under a lower surface of the vane plate and containing low-pressure refrigerant gas, a pressure of the low-pressure refrigerant gas being lower than a pressure of the compressed refrigerant gas; wherein the back pressure mechanism comprises: a back pressure chamber provided at an upper surface of a main frame, the back pressure chamber configured to be in tight contact with the lower surface of the vane plate; and a low-pressure gas communication part for introducing the low-pressure refrigerant gas into the back pressure chamber; wherein the back pressure chamber is configured as a circular groove.