Analysis of nonlinear vibration response to wear fault of big-end bearing shell of connecting rod in the ultra-high pressure five-cylinder plunger pump

Abstract

The ultra-high-pressure five-cylinder plunger pump is core equipment in multi-field, with its important components, such as big-end bearing shell of connecting rod, being prone to wear under high-intensity operation. However, the vibration characteristics of this type of equipment are complex and are currently not adequately researched. In view of this, this paper takes a certain model of five-cylinder fracturing pump as the research object. A rigid–flex coupling model of fracturing pump considering the wear fault of the big-end bearing shell of connecting rod is established. And taking the pressure-flow variation at the hydraulic end as boundary condition, the influence of wear degree and position on its vibration response is revealed. The results show that the collision force, centroid displacement, and vibration acceleration of the big-end bearing shell of connecting rod are mainly affected by the clearance collision parameters. Among them, the vibration acceleration is also affected by the collision between the connecting rods. For connecting rod big-end bearing shell with abnormal clearances, the collision force average amplitude and the centroid displacement effective value of it, and the vibration acceleration effective value at the corresponding measurement point all increase with the degree of wear increases. The vibration acceleration effective value at remaining measuring point decreases, and the further away from the connecting rod of abnormal clearance, the decline tends to be gentle. The research results provide a theoretical basis for the optimization of structural performance and the development of fault diagnosis technology of the five-cylinder plunger pump.