The Dynamic Analysis Of Reciprocating Air Compressor Crankshaft

Reciprocating compressor plays an important role in industry,but it also produces severe vibration and noise while it is running.With the development of society,tolerances on allowable vibration levels are becoming more and more stringent due to continuously improving human comfort.To keep the dominate position in the competitive market,manufacturers have to deal with the issue of vibration and noise immediately.To reduce vibration of air compressor,cylinder pressure is the key parameter of dynamic analysis which is usually difficult to directly measure.Based on this situation,in order to obtain the cylinder pressure,a way to identify the excitation of the torsional vibration of the air compressor was developed by means of force identification.In this thesis,some researches were conducted aiming at obtaining the cylinder pressure.Firstly,the torsional vibration test of the air compressor was carried out,and the test result of free vibration and forced vibration was obtained,which provided data for the subsequent force identification.And a problem of the torsional vibration measurement was solved which was caused by the uneven adhesion of the zebra belt at the interface of shaft.Secondly,the torsional vibration analysis model of the gear pair and the the crankshaft with multiple gears were studied which was the foundation for force identification.Then,a method of on-line identification of the dynamic torsional stiffness of elastic coupling based on the natural frequency measurement was developed which provided an accurate parameter for torsional vibration analysis.Then,in order to obtain the cylinder pressure,the excitation for the forced vibration of the crankshaft was recognized,and the cylinder pressure was calculated using the recognized torque.Finally,the orbit of shaft center of the air compressor was tested and compared with the calculated results to verify the correctness of the obtained cylinder pressure.