Hiroaki Inoue and Hiroshi Yoshida

Abstract:
More than 90% of the CO₂ emissions in the lifecycle of machinery, from production to scrapping, are caused by its fuel consumption at the time of operation, and any decrease in fuel consumption is directly linked to a decrease in greenhouse gas emissions. For this reason, we have developed a hybrid system for a hydraulic excavator – construction machinery with the highest number in use in Japan. This system uses an electric motor for the revolving upper structure and regenerates, using a capacitor, energy hitherto released as heat when braking. Sales of the 20 ton class hydraulic excavator PC200-8E0 started in 2008 [1]. We confirmed an average decrease of 25% in fuel consumption using data from an on-board vehicle management system. This corresponds to a 20 ton decrease in CO₂ emissions per vehicle per year. For further popularization of hybrid excavators, we updated the hybrid components in late 2010 and carried out a full model change. This is presented below in greater detail.

Keywords: hydraulic excavator, hybrid