Is the motor used for electric hoists different from other ordinary motors?
The electric motor used by the electric hoist works intermittently, Its characteristics are frequent starting, braking or reversing, and the size and direction of the load often change. Therefore, the electric motor used in electric hoists is different from ordinary motors, it requires high mechanical strength and overload capacity to adapt to mechanical vibration or shock. In order to reduce the inertia during starting and stopping, the rotor is made relatively slender.
Electric hoists for cranes mainly use induction motors. There are two types of squirrel-cage type and winding type. They are composed of two basic parts: the stator and the rotor. The rotor windings are embedded in the grooves of the rotor core and connected in a star shape. Each phase of the rotor winding is connected with three slip rings of the rotating shaft by flat copper bars, and then connected with additional resistance through the slip rings.
The winding motor rotor winding is connected with additional resistance, which can improve the starting performance and speed regulation of the motor to adapt to frequent starting, overload and shock. Therefore, wire-wound motors are widely used in cranes and electric hoists.