Abstract: During the running of the motor, the vibration is caused by the unbalance of the bearing driven by the rotating blades, which is transmitted to the wall by the motor bracket, and then reverberation is produced on the wall surface of the reverberation room, and low-frequency resonance sound is produced, which causes the discomfort of consumers. The low-frequency resonance noise of outdoor motor of air-conditioner is analyzed and studied. Through noise source identification and frequency spectrum analysis, noise source is weakened, noise transmission path and noise radiation angle are optimized, such as improving the motor structure mode, speed, blade matching and other measures, effectively improve the low-frequency resonance motor noise, improve the sound quality.

Key words: Air-conditioning motor, Noise source, Low-frequency noise, FTA analysis