前言近十年来,随着美国及世界各国对铁路运输要求的日益增长,EMD(GM 公司电气动力部)对机械部分和电气部分曾进行了广泛的研究以维持其高性能的要求。因此在若干领域,包括柴油机、发电机、牵引电动机、电控以及走行部——转向架等方面作出了重大的改 Foreword In the recent decade, as the United States and other countries in the world have been demanding more and more rail transportation, EMD (GM Electrical and Mechanical Department) conducted extensive research on mechanical parts and electrical parts to maintain their high performance requirements. Therefore, major changes have been made in a number of areas, including diesel engines, generators, traction motors, electric controls, and running gear-bogies