Permanent magnet synchronous motor for hoisting mechanism of direct-drive crane

The invention discloses a permanent magnet synchronous motor for a hoisting mechanism of a direct-drive crane; the permanent magnet synchronous motor comprises a permanent magnet synchronous motor shell, a stator winding, a stator iron core, a permanent magnet, a rotor, a winding drum revolving shaft and a winding drum; and the permanent magnet synchronous motor has more than 20 poles. In the invention, by increasing the number of the poles of the permanent magnet motor, a variable-frequency power source is adopted to realize low-speed operation of the motor, high torque is output, the motor directly drives the load to work, a speed reducer is canceled, the structure is simple and practical, and the working efficiency of the system is improved; a rotor structure adopted by the invention can effectively solve the problem of difficult assembly of the permanent magnet motor; rotor magnetic poles and magnetic separation steel rings commonly protect the permanent magnet from being damaged when in assembly; reluctance torque is reduced to be zero in the installation process, the installation difficulty is reduced, and requirements and dependence to installation tools (special mounting equipment) is reduced, and the quality of the rotor and the complexity of the rotor structure are greatly reduced.