Stator for BLDC motor and BLDC motor having the stator, power transmission device for washing machine, driving device for washing machine and full automatic washing machine using the same

A driving device for a full automatic washing machine having an inner tub and a pulsator rotatably combined in the inner tub, the driving device comprising:

• a brushless direct-current (BLDC) motor that produces a rotational force that rotates the pulsator and the inner tub, the BLDC motor includes a double-rotor having inner and outer rotors, a number of N-pole and S-pole magnets arranged on the outer circumference of an inner yoke and the inner circumference of an outer yoke, opposing magnets being arranged to have a reverse polarity;
• and
• an integral type stator having an annular contour and installed with a mutual gap between the inner and outer rotors, the stator including:
• a plurality of stator core assemblies, each stator core assembly including a division type stator core, a bobbin received on the division type stator core and a coil wound on the bobbin, each bobbin having inner and outer flanges having first and second coupling protrusions respectively formed thereon at lower-center portions of the inner and outer flanges;
• a sensor holder combined with a plurality of Hall sensors mounted therein, the sensor holder having multiple coupling protrusions extending from a bottom thereof;
• a printed circuit board (PCB) having the plurality of stator core assemblies mounted thereon, the PCB having an annular central area with a number of conduction lines printed on a surface thereof to connect the coils of the plurality of stator core assemblies to a respective electrical phase of a three phase circuit arrangement and a circuit area having multiple sensor holder coupling holes for receiving the multiple coupling protrusions respectively to thereby position the Hall sensors at a lower portion of the inner yoke, the PCB further including a plurality of coupling areas each extending radially from an opposing inner and outer side of the central area to define transverse projections therefrom, each coupling area being smaller in area than an area of a lower end of a corresponding one of the plurality of stator core assemblies, wherein the PCB is integrally formed with the stator core assemblies by a thermosetting resin to form a stator PCB assembly, and wherein each coupling area has first and second coupling grooves formed therein for receiving the first and second coupling protrusions of the bobbin of a corresponding one of the stator core assemblies;
• and
• a stator holder integrally formed with the stator PCB assembly by insert-molding;
• a first wash axle fixedly combined with a rotor support frame that is extended from the double rotor of the BLDC motor so as to rotate;
• a second wash axle having one side is linked with the pulsator, and through the other side receiving the rotational force from the first wash axle, to make the pulsator rotate in a forward/reverse direction;
• a first dehydration axle coaxially combined on the outer circumference of the first wash axle, and affixed to the rotor support frame so as to rotate;
• a second dehydration axle having one side is connected with the inner tub, and through the other side receiving the rotational force from the first dehydration axle, to make the inner tub rotate;
• a gear unit transferring the rotational force between the first dehydration axle and the second dehydration axle and between the first wash axle and the second wash axle;
• and
• a clutch unit controlling rotation of the first dehydration axle at a wash stroke to thus make the rotational force generated from the BLDC motor transferred from the first wash axle to the second wash axle so as to make the pulsator rotate, and making the first dehydration axle rotatable at a dehydration stroke to thereby make the rotational force generated from the BLDC motor transferred to the second wash axle and the second dehydration axle through the gear unit, to thereby make the pulsator and the inner tub rotate simultaneously.