Abstract
These days, the capacity controlling method of automotive air conditioning (A/C) systems is changing from the cycling clutch type (on-off) to the variable displacement compressor type. The reasons are that the variable displacement type provides higher cooling performance as well as improved fuel economy and driveability when A/C is on. Considering the use of direct injection lean burn engines that will require a minimization in torque changes, we believe that the variable displacement compressor type will be of the major use in the next generation.
Due to the improvements made into the vehicle in terms of noise and comfort, noise requirements at A/C operation is getting increasingly severer, which will require advanced noise reduction technologies. This paper presents an analysis of noise mechanism and a noise reduction method in the use of variable displacement compressor.