Series wound rotor double-speed three-phase asynchronous motor for lifting is a new type motor developed as a complete set of the lifting units of the crane.The high-speed electrode of the motor is used for running with load and the low speed electrode for the slow positioning process and it has the characteristics of stable starting, small switching current, small mechanical shock, simple structure and simple operation and so on.

The stator of this motor has 6 leadouts;The rotor adopts a set of compound coil line set and the design of the high-speed electrode can be carried out through three external slip rings;And the low-speed electrode rotor winding has been connected into a loop and the high impedance can automatically appear, at this time, it is equivalent that the squirrel cage motor runs.Since the rotors at both electrodes have high impedance, which can ensure a larger starting torque and the switching torque as well as effectively limit the starting current and the switching current.