Patent ID: 6398515
Filing Date: 2002-06-04
Classification: F04B

Abstract:
A variable displacement type compressor comprising:a housing; an intake chamber located within the housing; a discharge chamber located within the housing; an operating chamber located within the housing; a reciprocating-piston compressing mechanism located within the housing, wherein a piston draws refrigerant gas from the intake chamber and discharges the refrigerant gas to the discharge chamber; a swash plate for driving the piston, wherein the swash plate is located in the operating chamber; a drive shaft extending between the interior of the housing and the exterior of the housing, wherein the drive shaft drives the swash plate, and the swash plate inclines with respect to the axis of the drive shaft in accordance with the pressure difference between the operating chamber and the intake chamber; a first connecting passage having a fixed opening amount for connecting the operating chamber to the intake chamber; a second connecting passage for connecting the operating chamber to the discharge chamber, wherein the displacement of the compressor is varied by controlling the opening amount of the second connecting passage; a seal for preventing leakage of refrigerant gas from the interior of the housing to the atmosphere, wherein the seal seals a gap between the drive shaft and the housing, and one side of the seal is exposed to the atmosphere; an isolation chamber formed in the housing to surround a portion of the drive shaft, wherein the isolation chamber is separate from the operating chamber, one side of the seal is exposed to the interior of the isolation chamber, a pressure difference is applied to the seal by the difference between the pressure of the isolation chamber and the atmosphere; a pressure reducing passage connected to the isolation chamber; and a pressure reducing device for reducing the pressure in the isolation chamber when the compressor is operating by drawing refrigerant gas from the isolation chamber through the pressure reducing passage, wherein the pressure reducing device reduces the pressure difference applied to the seal and lowers the pressure in the isolating chamber with respect to the pressure of the operating chamber, by removing refrigerant gas from the isolation chamber through the pressure reducing passage.