Abstract: Reciprocating vacuum pump working noise, sound quality is not good. In order to improve the sound quality of vacuum pump during operation, the pipe noise of air outlet of reciprocating vacuum pump is studied. Firstly, the near field noise at the outlet of the vacuum pump was collected to obtain the frequency domain characteristics of the vacuum pump noise. It was found that the noise at the outlet of the vacuum pump was mainly concentrated in the 0~4000 Hz frequency band. Then, the noise reduction scheme was designed for the frequency segment, and the muffler series was adopted to eliminate the passing frequency of transmission loss curve, and the Virtual Lab software was used to simulate the performance of the series muffler. Finally, the design scheme was installed at the outlet of the vacuum pump to verify the noise, and the experimental verification of gas flow loss was carried out. The results show that the noise reduction effect of the series muffler on the outlet of the vacuum pump is more than 25 dB(A), and the gas flow loss is 9.8%. The research results can be used for reference to improve the sound quality of vacuum pump.

Key words: Vacuum pump, Muffler, Pipe noise, Acoustic simulation, Transmission loss