Effect of pump leakage on slip and pressure loss in a hydraulic cylinder drive

Abstract

Pump leakage plays a critical role in the safety as well as the functioning of hydraulic drives. Studying the effect of pump leakage on the dynamics of hydraulic drive can improve the drive safety by giving insight into dynamic symptoms of leakage fault and can improve the functioning range of drive by giving insight into the slip and pressure losses of the drive during steady and transient states. This article aims at dynamic characteristic analysis of pump leakage in a hydrostatic drive with linear actuator and lever mechanism. Such hydraulic drives are used in several earth moving machines e.g. crane, dumper truck, front loader etc. To carry out this analysis, the system model is developed using the Bond graph technique and validated using real measurements. Finally, the developed model is utilized to generate and analyse the system dynamics under different intensities of pump leakage. The steady state portion of the results indicate that the pump leakage results in significant slip or flow loss as compared to pressure loss. However, the transient portion of the result indicates that effect of pump leakage is almost same on both slip loss as well as pressure loss of the drive.