Rotor Dynamics Analysis Of High Pressure Small Flow Gear Compressor

High pressure and small flow gear compressor is a new kind of centrifugal compressor. It has the characteristics of small flow rate, high outlet pressure, large transmission ratio in the gear transmission system and high rotor speed, etc. There is no such products on the domestic market at present, belongs to the development of new products.In the gear transmission system, the interaction between the two rotor gears makes the gear rotor vibration to the coupling of torsional vibration and bending vibration. Therefore, the rotor dynamics analysis of high pressure and small flow gear compressor is essential in the design and development stages.In the analysis of dynamic characteristics of rotor, we should not only analyze the single rotor, but also establish the coupled bending and torsional vibration model of rotor system as a whole to analyze the dynamic characteristics of the rotor system.In this paper, the mathematical model is set up by using the lumped mass method. According to the mathematical model, use the modified Riccati transfer matrix method to compile the transfer matrix, use the MATLAB software to solve the transfer matrix equation, and obtain the three rotor critical speed in the uncoupled case, mode of vibration and static unbalance response. According to the mathematical model, use the whole transfer matrix method, compile the transfer matrix for the rotor system, and use the MATLAB software to solve the transfer matrix equation, obtain the critical speed of the rotor system in the coupled case, mode of vibration and unbalance response.The results show that, with the existing design parameters, the rated speed of the compressor rotor system are far away from the critical speed, the steady imbalance response are in the allowed range. Therefore, the rotor system of the compressor can be smooth and safe operation with the existing design parameters.