Abstract: Machining systems are in enormous quantity and the potentiality for energy-saving and emission-reduction to environment is great, which also involves lots of scientific problems, so that a number of studies on energy efficiency of machining systems are being done on the international scene in recent years. The extended connotation of energy efficiency of machining systems is summarized firstly. The state of the art of energy efficiency research on machining systems is investigated through the lenses of general overview and category of research objects. Based on the review, a content architecture framework of energy efficiency research on machining system is advanced, which includes three objects (machine tools, workpieces and system), five basic technology issues (the energy efficiency of energy consumption links and energy consumption components, the modeling of energy consumption and energy efficiency, the energy efficiency characteristics of machine tools and workpieces, the evaluation of energy efficiency, and the energy efficiency monitoring and management of machining systems), two kinds of functional techniques (high-energy-efficiency operation of machining system and high-energy-efficiency design of machine tools) and two objectives (improve the energy efficiency on machining system and develop high-energy-efficiency machine tool). Finally, the future trends of the energy efficiency research for machining system are concluded, which can be detailed as integrated modeling of energy efficiency, platform construction of energy efficiency assessment, energy consumption quota of machining task, energy efficiency optimization during the operation of machining systems and energy efficiency integration during the design of machine tools.

Key words: Architecture, Development, Energy efficiency, Machining system, State of the art