Structural Dynamics Analysis and Optimization of an Oil-Free Piston Air Compressor Based on Vibration and Noise Characteristics

Air compressors play an important role in energy, mining, civil engineering, and transportation engineering. However, the abnormal vibration and noise of air compressors may pose a serious threat to the structural stability and smooth operation of these types of engineering equipment. To address the broadband noise and vibration problems of a new oil-free piston air compressor, we developed a hybrid optimization method that combines experimental testing, theoretical evaluation, and numerical simulation. Firstly, we conduct noise experiment testing, identify the frequency band of aerodynamic noise using a coherence analysis method, and design orthogonal experiments to further optimize pipeline noise. Then, the vibration characteristics were discussed from both theoretical and simulation perspectives. The dynamic balance has been redesigned on the spindle counterweight plate to reduce the force on the bearings, and a multi-body dynamics model has been constructed to demonstrate the effectiveness of the optimization. Subsequently, a finite element model of the compressor housing was established to analyze the radiation noise characteristics. Finally, three weak points in the structure were selected as key objects, and the structural stiffness was increased to improve vibration stability. The simulation results of radiated noise show that the proposed design scheme can effectively reduce vibration and noise, with a maximum noise reduction rate of 7.45%.