Compressor HVAC: Description and Operation

A/C Compressor and A/C Clutch Assemblies

The FS-10 is a swash-plate design 10-cylinder aluminum compressor utilizing the tangential design of mount. The compressor mainshaft is driven by a belt from the engine crankshaft pulley. A one-piece lip-type seal (replaceable from the front of the compressor) is used to seal the A/C compressor at the shaft opening of the A/C compressor assembly. Five double-acting pistons, positioned axially around the compressor shaft, operate within the cylinder assembly. The pistons are actuated by a swash plate that is pressed on the compressor shaft. The swash plate changes the rotating action of the shaft to provide a reciprocating driving force to each of the five pistons. This driving force is applied, through shoes, to the midpoint of each of the double-ended pistons. Reed-type discharge valves are assembled on the valve plate that is located with the suction reed valve between the cylinder assembly and the head at each end of the A/C compressor. The heads are connected to each other by gas-tight passageways through the cylinder assembly, that direct the refrigerant gas to the suction and discharge. ports located in the rear head.

A magnetic clutch is used to drive the compressor shaft. When voltage is applied to the clutch field coil, the clutch plate and hub assembly (which is solidly coupled to the compressor shaft) is drawn rearward by magnetic force toward the pulley that rotates freely on the compressor front head casting. The magnetic force locks the clutch plate and hub assembly and the pulley together as one unit. The compressor shaft then turns with the pulley. When voltage is removed from the clutch field coil, springs in the clutch plate and hub assembly move the clutch plate away from the pulley. As a result, the clutch plate and hub assembly and the compressor shaft cease to rotate.