No. 1330
	Sustainable technology for technical inheritance support in DC machines
	DC machine sustainable technology Investigating R&D Committee
	Keyword : DC machine, Technology inheritance, Sustainable technology
	DC machines have been applied to various industrial applications, including steel rolling mill applications, for more than 100 years. However, since 1990s, AC adjustable speed motors have been developed and popularized, resulting historical end of DC machine manufacturing era in Japan, except for specific medium class DC motors for general industrial applications. Recently, DC machine manufacturer are also closing their field service business to their users. However, almost users cannot replace their DC motors to AC variable speed motors, due to their plant facility investment decrease under the recent lower economic growth, resulting their farther application of existing old DC motors, for a long time. Considering above technical background, this technical report deal with how to inherit DC machine technologies, among DC machine maintenance engineers and DC machine repair maker engineers. This report also deal with global trend for the DC machine technology inheritance problems
	©2007. The Institute of Electrical Engineers of Japan