Patent ID: 9255354
Filing Date: 2016-02-09
CPC Classification: B23P,D06F,H02K,Y02B,Y10T

Claim Text:
1. A method for controlling a washing machine that includes a main body defining an outer appearance, a tub disposed within the main body, a main drum rotatably mounted in the tub, a sub drum mounted in the main drum to be relatively rotatable with respect to the main drum, a outer shaft for rotating the main drum, an inner shaft for rotating the sub drum, being disposed inside the outer shaft, a driving motor having a stator, an outer rotor connected to the inner shaft and rotatable outside the stator, and an inner rotor connected to the outer shaft and rotatable inside the stator, and a control unit to control operations of the outer rotor and the inner rotor, the method comprising: initially operating the driving motor with the same starting RPM smaller than target RPMs of the outer rotor and the inner rotor; and operating the outer rotor and the inner rotor with the respective target RPMs when a predetermined time lapses after initially-operating the driving motor.