A 7 -Cylinder IVD Compressor for Automotive Air Conditioning

A 7-cylinder, wobble plate type, infinitely variable displacement, (IVD), compressor has been developed to meet the following requirements as set forth by the world automotive manufacturers:

1. 1
   Wide range of capacity control to eliminate clutch cycling which causes temperature and humidity fluctuations of louver outlet air and unexpected engine load variations
2. 2
   Near perfect protection of the evaporator against icing
3. 3
   Reliability under all field operating conditions
4. 4
   Quiet operation in a compact and lightweight package to suit the new trends in automotive design.

A simpler mechanism has been applied to the variable angle cam drive and wobble plate rotation prevention method than with the conventional IVD compressor. The 7-cylinder design, with fewer parts for the piston drive mechanism, enables a quiet compressor of 161.3 cc displacement in a 118 mm diameter casing. An internal control valve is integrated in the center of the valve plate assembly. Mass flow rate compensation is attained using a discharge pressure sensing rod which modulates the opening pressure of the bellows valve.