Study on the vibration characteristic of crankshaft of single cylinder compressor based on crosshead settlement

HUANG Zhiqiang; WANG Cheng; LI Tao; ZHANG Guoxu; LI Gang

doi:10.16579/j.issn.1001.9669.2025.11.007

Abstract：The acceleration of the reciprocating parts of the compressor with the crosshead settlement fluctuates violently,and the comprehensive piston force becomes larger,which leads to the increase of the vibration amplitude of the crankshaft and the instability of the vibration.Therefore,this paper firstly studied the kinematic law of the crosshead settlement on the crank-connecting rod structure,and established the differential equation of the torsional vibration of the crankshaft.Subsequently,the vibration response characteristics of the crankshaft were solved by the mean filtering-Runge-Kutta method.Finally,the influence of the crosshead settlement,motor speed and reciprocating mass of the piston assembly on the crankshaft vibration amplitude,phase trajectory and amplitude-frequency diagram was discussed.The results show that with the increase of the crosshead settlement,the"serrated"fluctuation of the crankshaft phase space trajectory line is intensified,and the torsional angular velocity shows an upward trend.When d=0.25 mm,the torsional angular velocity amplitude increases by 23.6%compared with that without the settlement,and the crankshaft vibration state changes from frequency doubling period to chaos.As the motor speed decreases,the torsional angle and vibration state fluctuation of the crankshaft are controlled.As the reciprocating mass of the piston assembly decreases,the peak frequency response decreases,which helps to control the crankshaft torsion angle.The research can provide a theoretical guidance for predicting the vibration state of the crankshaft and the torsional vibration control of the crankshaft under the condition of the crosshead settlement,and ensure the stable operation of the crankshaft.