An efficient, compact and low-cost Dual Cylinder Hydrostatic Actuator (DCHA)

Abstract

Pump-controlled systems are highly efficient alternatives to the high throttling losses of valve-controlled systems. Closed-circuit systems have been widely adopted for rotary loads, but the asymmetrical nature of linear actuators has limited their acceptance. Hydrostatic linear actuators typically are costly or complex, inefficient or exhibit low force density. This paper presents a Dual Cylinder Hydrostatic Actuator, which is highly efficient for both resistive and overrunning loads, uses commercially available low-cost components, and provides the same high force of a conventional system in a similarly sized system. A steady-state model is presented, along with an experimental validation on a small-scale apparatus. An analysis of a full-scale application is performed, including strategies for mitigation of energy losses.

Keywords:

• Efficiency
• pump control
• hydrostatic
• energy recovery

Acknowledgements

This work was partially funded by a University of Saskatchewan Forge Ahead Fund grant. The author would also like to acknowledge the assistance during experimental work of Douglas Bitner, Debdatta Das, Hanming Luan and Kyle Mostat.