Numerical research on dynamic responses of the emulsion pump crankshaft under multiple working conditions

The stability and safety of emulsion pumps are significantly influenced by crankshafts. However, the crankshaft of the emulsion pump bears complex torsional and bending stresses during operation; thus, it is prone to failure. The purpose of this paper is to determine the dynamic response of the crankshaft under various working conditions. The mechanical model of the power end of the emulsion pump is constructed, and the dynamic model is established by LS-DYNA. The stress distribution characteristics of the surface element of the crankpin in the pulsating impact cycle are analysed, and the dynamic response of the crankpin under multiple working conditions is studied. The results show that under the action of pulsating impact, the edge position of the crankpin is more likely to fail, especially at the second crankpin, and the maximum stress can reach 213 MPa. The dynamic impact of the connecting rod on the crankpin is positively correlated with the flow of the emulsion pump and the hydraulic pressure on the plunger, and the crankshaft vibration becomes more noticeable as the flow rate rises. Doubling the flow rate increases the vibration by 73.9 %. Our research results provide a reference for avoiding the failure of the crankshaft and optimizing the design.