Experimental analysis of slewing energy recovery potential of large hydraulic excavator

Large hydraulic excavators, characterized by large inertia of slewing movement, frequent accelerating and braking, have ideal working conditions for energy recovery and reuse. This paper investigates the slewing energy-saving potential of large hydraulic excavators via experiments conducted under different working conditions. Firstly, the working principle and energy flow of the slewing system of the hydraulic excavator are analyzed, and the evaluation indexes for energy-saving potential are proposed. Additionally, a 50 ton slewing experimental prototype is established, and comparative experiments are conducted. The energy flow analysis demonstrates that the energy loss due to slewing overflow is the primary factor for the low energy utilization rate of the slewing system. Finally, the influence of engine speed, slewing angle, and load on the potential of slewing energy recovery are analyzed. The experiential results reveal that the energy-saving contribution rates of accelerating and braking range from 42% to 45.36% while the energy regeneration rate is 56% under the single-action condition. And the comprehensive contribution rate of accelerating and braking energy is about 9.2% under the compound-action working condition, which has a significant energy-saving potential.