Electric energy recovery system for a hydraulic forklift - theoretical and experimental evaluation

Energy efficiency has become a major research issue in all fields of engineering. As electrical drives have fast torque response capability and high controllability, they are penetrating new fields of engineering. Opportunities of utilising electric servo drives in the control of hydraulic lifting systems and enabling energy recovery in them are studied. In this study, the control of the hydraulic lifting and lowering system is carried out directly by an electric-servomotor-driven hydraulic machine. The efficiencies of the experimental drive system and its components are determined. At maximum, 66% of the potential energy was recovered in the low-power drive and improvements could still be achieved.