Wire Rope Resistor Motor

     Bridge crane motors are mainly classified according to rotor structure and working system, among which three-phase wound asynchronous motors are the most widely used core drive type. ‌‌
     1) Classified by rotor structure
     Three phase wound asynchronous motor: mainstream configuration. The rotor circuit can be connected to a resistor through a slip ring, which has the characteristics of high starting torque, low starting current, and smooth speed regulation. 

     It is perfectly suitable for frequent starting and stopping, heavy load starting, and variable speed working conditions of cranes.
     Three phase cage (squirrel cage) asynchronous motor: simple structure but small starting torque and difficult speed regulation. Only used in some operating mechanisms that do not require high speed regulation or in modern transformation schemes that cooperate with frequency converters.
     DC motor: Although it has excellent speed regulation performance, it has gradually been phased out in modern      AC power supply environments due to its complex maintenance and high cost (vulnerable brushes/commutators).
     Synchronous motor: With a constant speed and complex speed regulation, it is not suitable for crane scenarios that require frequent speed changes and is rarely used. ‌‌
     2) Classified by work system
     Repetitive short-term working system: All mechanism motors of the crane belong to this category. The characteristic is that it works and stops periodically, with a short working cycle. 

     The equipment cannot reach thermal equilibrium and needs to be specially designed to withstand frequent thermal and mechanical impacts. ‌‌