The invention discloses a permanent-
magnet brushless self-adaptive variable-speed motor. The permanent-
magnet brushless self-adaptive variable-speed motor comprises a
stator, a rotor shaft, a rotor and a centrifugal
magnetism adjusting mechanism. The permanent-
magnet brushless self-adaptive variable-speed motor is characterized in that the rotor of the motor is divided into more than two parts, one part is a main rotor part, occupies most area of a
stator air gap, is mainly used for energy conversion and fixedly connected with the rotor shaft, and output mechanical torque through a rotary shaft, the remaining part is a
magnetism adjusting rotor part, is arranged on one side of the main rotor part on the shaft and can rotate by a certain angle around the shaft, the shoe
block type centrifugal
magnetism adjusting mechanism is arranged on the magnetism adjusting rotor part, is coupled with a center wheel installed on the rotor shaft and can rotate around the center wheel, a reset spring is fixed between the magnetism adjusting rotor part and the main rotor part,
angular displacement happens to the magnetism adjusting rotor part according to the change of the rotating speed under the combined action of
centrifugal force and
spring force and then the state of
flux linkage is changed, the motor can be self-adaptive to the change of the moment of resistance, the characteristic of the
constant torque at a rated speed and constant-power variable speed at a speed higher than the rated speed of the motor is achieved, and the characteristic is particularly suitable for driving vehicles.