Experimental Characteristics of Frequency Modulated Noise of Compressor

摘要

The electric motor, pump system and acoustic cavity resonances are the noise sources of a hermetic reciprocating compressor and there are radiated from inside to outside of the compressor. In the compresso'r, Frequency Modulated Noise(FMN) occurred, like a pure tone and sweeps from a frequency band to other frequency band. The FMN affects the sound quality of some acoustic field so it has to control the FMN to increase the sound quality of household compressor. In this study, the characteristics and radiating mechanism of FMN are identified by experimental methods, such as analysis of the acoustic frequency response characteristics of a compressor accordance with the change of the amount of oil, and those of the transmitted vibration from the motor and pump to the supporting snubber on the lower-shell. We can controlled the FMN characters by some modifying or eliminating the source and paths of compressor. Especially, it is revealed that the higher mode as a local cavity resonance of the compressor due to the oil surface pattern is the main source of the FMN.