Adjustable Linkage Pump: Efficiency Modeling and Experimental Validation

Abstract

Variable displacement pumps are a key component to a variety of mobile and industrial hydraulic systems, yet the efficiency of existing pump architectures is poor at low displacement. As a solution to this issue, a new pump architecture is proposed that eliminates the planar hydrodynamic joints of a conventional architecture with rollingelement pin joints in an adjustable linkage. This new architecture uses an adjustable sixbar linkage that reaches true zero displacement and has the same topdeadcenter (TDC) position regardless of displacement. In this work, the linkage kinematics and dynamics are discussed, an energy loss model is developed and used to drive design decisions of a first generation prototype, and experimental results are presented to validate the model. It is shown that this linkagebased, variable, positive displacement architecture shows promise as a highly efficient alternative to existing pump architectures across a wide range of displacements.