Innovative Hybrid Powertrain for Energy Consumption Reduction of Hydraulic Excavators

This paper proposes an innovative powertrain to improve energy efficiency in hydraulic excavators. The powertrain combines an engine with an electric motor/generator to drive the main pump. By adjusting the gear ratios, the working point of the engine can be optimized to stay in its high-efficiency region. Additionally, during the boom cylinder's moving down process, pressurized hydraulic energy is converted to electrical energy and stored in a battery using energy conversion devices. The stored electrical energy can then be used to compensate for any power deficiencies in subsequent cycles. An experimental test bench was constructed to evaluate the advantages of the proposed system. The experimental results showed a 54% improvement in energy-saving efficiency compared to a conventional system.