Drum washing machine

Abstract

The present invention is directed to a drum washing machine. In particular, the drum washing machine includes a rotating tub, wherein the rotating tub has a cylindrical drum having a front formed with a circular opening through which laundry is put into the rotating tub and having a rear that is closed. The drum washing machine further includes a DC brushless motor for generating a driving force for wash, rinse and dehydration operations and a rotor. The drum washing machine further includes a rotational shaft of the motor having a front end directly fixed to the rotating tub and a rear end fixed to a core of the rotor, so that torque developed by the motor is directly transmitted to the rotating tub. A current detector is provided in the drum washing machine for detecting electric current flowing into the motor. A torque control unit is also provided in the drum washing machine for performing a vector control for the motor on the basis of the current detected by the current detector, so that torque developed by the motor is rendered optimum for at least the wash and dehydration operations. A speed control unit for controlling a rotational speed of the motor, based on the current detected by the current detector and a laundry amount determining unit for determining an amount of laundry in the rotating tub, based on a magnitude of an accumulated value of torque current in a period when a rotational speed of the motor is accelerated are also provided in the drum washing machine of the present invention.