The working process of the ac compressor can be divided into 4, namely compression, exhaust, expansion, inhale. When the crankshaft connecting piston, through the drive, the cylinder wall motion, the cylinder and the piston top form working cubage regular changes will, thus plays in the refrigeration system and compression of refrigerant.

The crankshaft connecting rod type ac compressor is the first generation compressor, it is widely, manufacturing technology, simple structure, and the maturity of materials and the processing requirements, cost low low. Wide adaptability is strong, can adapt to the pressure and large, strong maintainability.

But the crankshaft connecting rod type compressor also have some obvious disadvantages, such as high speed, the machine can achieve large and heavy, not easy to realize the lightweight. Exhaust discontinuous flow volatility, and work to greater vibration.

Because of the crankshaft connecting rod type ac compressor, there has been little by little displacement compressors, crankshaft connecting rod structure type compressor are currently used in passenger cars and trucks in the air conditioning system of large displacement.