What features of the CVC compressor distinguish it from other compressors?
An OE compressor with the pistons still inside and then the pistons removed. This is a typical set up, using pistons fixed to the swash plate.
Very light pistons float, as in they are not fixed, on the swash plate. In essence, this reduces weight, friction and pumping losses, which allows the output of the comparison with less emission, less heat and more efficiency. This also means they are quieter and more durable.
Fixed displacement compressors have a swash plate, which is set at a fixed angle. That means, whenever the compressor is turning the pistons are always moving through the same travel, compressing the gas.
The only variables, therefore, are compressor speed and quantity of refrigerant in the system. Fixed displacement compressors have a clutch which turns it on and off.
Variable Displacement CVC
Variable displacement compressors have a swash plate, which is held at an angle with two springs.
These will react to pressure, and the swash plate can be adjusted. The actuator (by which you can identify this as a variable compressor) controls the pressure to the swash plate. This means that there is a variable output for this compressor.
It is so effective that in some cases there is no clutch fitted to these and they spin continuously, varying the refrigerant compression according to demand. The variables therefore are compressor speed, quantity of refrigerant in the system and swash angle. Variable displacement piston compressors are either swash plate (CVC) or wobble plate (V5 and V7).