A bearing structure for a motor rotor includes an outer periphery with an engaging portion tightly engaged to an inner periphery of an axle tube. The bearing structure further includes an axle hole for pivotally supporting a shaft of the motor rotor. A longitudinal length of the axle hole is longer than that of the engaging portion or a longitudinal length of the axle hole is longer than that of a connecting member interconnected between inner periphery of an axle tube and outer periphery of the bearing.