备用机械 meaning in English

stand-by machinery

Abstract : the technological requirements for mechanical back - up braking system and wheel - disk braking system applied on the magnetic levitation vehicles are described . the development and testing for the wheel - disk braking system are expounded
文摘:介绍了磁浮车辆上采用的备用机械制动系统和轮盘制动系统的技术要求，着重阐述了轮盘制动系统的研制及试验。