Subaru LEGACY 2002 Quick Reference Index page 494

COMPRESSOR
HVAC System (Heater, Ventilator and A/C)
B: RHD MODEL
1. GENERAL
The compressor basically consists of a rotor, radially movable vanes on the rotor, and a cylinder
two. The rotor is excentrically located in the cylinder and driven by the drive shaft to rotate together
with the vanes. Since the gas is compressed by rotation of the vanes, the compressor is called
"through vane rotary" type compressor.
The engine torque is transmitted to the drive shaft through a belt and a magnet clutch.
The two vanes intersect with each other at right angles as shown in the following drawing. As the
rotor rotates, the vanes' ends slide along the internal surface of the cylinder, so the vanes make
reciprocating motions. During rotation, the volume of each closed space formed between two ad-
jacent vane walls (referred to as "cylinder chamber" in the following description) changes and this
provides the compressor with a pumping function consisting of suction, compression and dis-
charge.
The front cylinder head has a discharge port and a discharge valve. When compressed in the cyl-
inder, high-pressure refrigerant gas forces the discharge valve to open and enters the oil separator
case where it is separated from oil it has contained. The cylinder head also has a temperature sen-
sor which prevents overheating that would occur if refrigerant gas is short during compressor op-
eration.
The rear cylinder head has an oil return valve which controls the quantity of oil for lubrication of
the cylinder chambers, and a sludge valve which, when liquid refrigerant is forced into a cylinder
chamber, prevents the liquid compression.
AC-22