桥式起重机电气调速系统的改造

主要研究桥式起重机主起升机构调速系统，为工厂桥式起重机电控系统改造提供一种参考。电气系统是桥式起重机的一个重要组成部分。起重机调速绝大多数需在运行过程中进行，而且变换次数多，故机械变速一般不太适合。大多数需采用电气调速。传统调速方案一般采用转子串多级电阻方式，先进的调速方案是PLC控制的变频器调速技术。

Improvement of the Electric Timing System on Bridge Crane

The electric timing system of the main lifting structure on bridge crane is researched in this paper for providing a reference to the improvement of the electric controlling system.As is known,the electric timing system is an important makeup for bridge crane,and most of crane timings have to be carried out during running.Since crane timing is frequent,mechanical shift is not so suitable and electric timing has to be employed.The traditional timing scheme uses rotor in series with multi-polar resistance,and the advanced timing scheme makes use of the technology of PLC controlled transducer.