Hybrid in Construction Machinery

Abstract

After second oil shock in 1978, fuel consumption cost has become an important evaluation factor for construction machinery, many improvements have been made to increase machine efficiency[1]. Recent year, as the Kyoto Protocol get effective, further effort on fuel consumption cut or CO2 cut is required for all machine makers. As the success of the hybrid system in automobile, construction machinery makers also put a lot of force on research to apply the hybrid concept in their own machines. This paper introduced the research and development of hybrid machinery in Hitachi Construction Machinery Co. Ltd , and also discussed the problems in this field.

Development of hybrid powered hydraulic construction machinery

“…According to its working content, sometimes the machine will share the total engine power with several actuators simultaneously, and sometimes it needs to concentrate the full power onto one actuator. The analysis of which actuator consumes more power, which actuator has more potential power to regenerate and how to downsize the engine power is a quite difficult problem in hybridization of these machines [3]. …”

“…The ZAXIS 200 hybrid hydraulic excavator is powered by a parallel hybrid system, and the new hybrid model uses an electric motor to drive the swing. When the swing is braking and the boom is going down, the energy could be converted into electric energy to be stored in the capacitor [3], and a fuel saving of 25% was recorded. In this machine, the engine rating power was not downsized to keep the total operation performance at the same level as the standard machine.…”

Review of Energy-saving Technologies in Modern Hydraulic Drives

“…Energy can be accumulated during the lowering of the load, idle movements of the working element or in another way, for example, when the entire unit brakes. As evidenced in a number of studies by scientists: Kagoshima et al (2007);Ochiai, Rye (2008); Rohit et al (2012);Wang, Wang (2012);Lin et al (2017) and the leading companies of construction and road machinery in the world: Caterpillar, Manitou, Komatsu, John Deere, JCB, New Holland, Volvo, Hitachi and Kubota.…”

Eigenfrequency of Hydraulic Systems of Loading Device

“…They are used as drives of heavy duty equipment (e.g. cranes, loaders and excavators) [1]. Furthermore hydraulic systems are characterized by relatively small dimensions in comparison with different drives.…”