Development of a Variable Displacement Adjustable Linkage Pump

Achievement date: 

Researchers at the NSF-funded Engineering Research Center (ERC) for Compact and Efficient Fluid Power (CCEFP) at the University of Minnesota—in partnership with the Georgia Institute of Technology, Purdue University, the University of Illinois at Urbana-Champaign, and Vanderbilt University—have developed a functional prototype of a multi-cylinder, variable-displacement linkage pump.


The adjustable linkage pump is capable of filling numerous commercial needs for a hydraulic pump with high efficiency at low volumetric displacement. Novel features of the adjustable linkage pump not only improve efficiency, but also allow the pump to be used in a wide range of applications and environments where current variable-displacement hydraulic pumps are unsuitable.


The variable-displacement adjustable linkage pump emerged as part of an affiliated research project at CCEFP focused on compressed air energy storage. The current pump prototype uniquely features the use of low-friction pin joints; the ability to reach both true zero displacement and the same top-dead-center position regardless of displacement; and the option to pump corrosive fluids.

The CCEFP team is exploring additional commercial applications as part of an NSF Partnerships for Innovation Accelerating Innovation Research (PFI:AIR) Technology Translation project. As use of the variable-linkage pump evolves, it will address several current gaps in the state-of-the-art: construction of a dynamic model of the pump; construction of a framework for multi-domain, multi-objective optimization of machines with mechanisms and applied optimization methods for water pumping applications; design of a multi-cylinder prototype for water pumping with low flow ripple; and prototype testing in industrial applications.