Complex washing machine and controlling method for the same

A washing machine comprising:

• a main washing machine for performing a washing or drying operation;
• and
• an auxiliary washing machine,
• wherein the auxiliary washing machine includes:
• a case for stably supporting the main washing machine, the case having a volume and height less than that of the main washing machine;
• a drawer configured to be forwardly extracted from and retracted into the case;
• an outer tub mounted in the drawer for storing wash water and having an opening formed in a central portion of a lower surface thereof;
• an inner tub rotatably mounted in the outer tub for shaking laundry;
• a bearing housing located inside of the opening of the tub, the bearing housing having an outer circumferential surface spaced from the inner circumferential surface of the opening of the outer tub by a predetermined distance;
• a motor fastened to a lower surface of the bearing housing, for providing a rotary force to the inner tub;
• a rotary shaft rotatably supported by the bearing housing and coupled to the inner tub through the bearing housing, for transmitting the rotary force from the motor to the inner tub;
• a damping unit for supporting the bearing housing and attenuating vibrations delivered from the motor or the inner tub to the bearing housing;
• and
• a first flexible sealing member configured to seal the opening in the outer tub and connected between the bearing housing and the outer tub so that the bearing housing vibrates independently of the outer tub, the first flexible sealing member attenuating vibrations of the bearing housing delivered to the outer tub.