Drum type washing machine

Abstract

A drum type washing machine of the present invention is a direct-drive washing machine including a washing-machine casing; a rotating drum with its drum rotation shaft horizontal or inclined; and a motor driving the rotating drum. The motor has a stator including a coil wound in a toroidal winding form and first molding resin; and a twin-type rotor including an outer rotor, an inner rotor, and second molding resin integrally molding them.

1 . A drum type washing machine comprising:
 a washing-machine casing having an opening through which laundry is loaded and unloaded;   a rotating drum having a drum rotation shaft in a horizontal or inclined direction relative to the casing; and   a motor driving the rotating drum,   wherein the machine is a direct-drive washing machine the drum rotation shaft of which is connected directly to a motor shaft of the motor, and wherein the motor includes:   a stator having:   a ring-like stator yoke;   a plurality of outer teeth projecting from the stator yoke in an outer circumferential direction;   a plurality, the equal number as the outer teeth, of inner teeth projecting from the stator yoke in an inner circumferential direction;   a plurality of outer slots formed between each of the outer teeth;   a plurality of inner slots formed between each of the inner teeth;   a coil wire-connected to the stator yoke between the outer slot and the inner slot in a shape of a three-phase star or a delta, wound in a toroidal winding form; and   first molding resin integrally molding the stator yoke, the outer slot, the inner slot, and the coil; and   a twin-type rotor having:
 an outer rotor disposed facing the outer teeth through a given air gap; 
 an inner rotor disposed facing the inner teeth through a given air gap; 
 second molding resin integrally molding the outer rotor and the inner rotor; and 
 the motor shaft connected to the outer rotor and the inner rotor. 
   
   
   
       2 . The drum type washing machine of  claim 1 , wherein the rotating drum has a bottomed, cylindrical water receiving tub at an outer circumference thereof, and the motor is fixed to a bottom of the water receiving tub. 
   
   
       3 . The drum type washing machine of  claim 2 , wherein the first molding resin has a plurality of attaching portions, which are fixed to the water receiving tub. 
   
   
       4 . The drum type washing machine of  claim 1 ,
 wherein the stator yoke has a plurality of through holes penetrating axiswise, and   wherein the first molding resin integrally molds the stator yoke, the outer slot, the inner slot, the coil, and the through holes.   
   
   
       5 . The drum type washing machine of  claim 4 , wherein each of the through holes is formed at an intersecting point of a straight line connecting a rotation-direction center of the outer teeth to a rotation-direction center of the inner teeth; and a center arc of the stator yoke. 
   
   
       6 . The drum type washing machine of  claim 4 , wherein the through holes have circular or elliptical cross sections. 
   
   
       7 . The drum type washing machine of  claim 1 , wherein the second molding resin has a plurality of ventilating holes penetrating in a direction of the motor shaft. 
   
   
       8 . The drum type washing machine of  claim 1 , wherein the second molding resin has a plurality of projections at a part thereof facing the stator in a direction of the motor shaft. 
   
   
       9 . The drum type washing machine of  claim 1 , wherein the second molding resin has a plurality of ribs at a back side thereof. 
   
   
       10 . The drum type washing machine of  claim 1 ,
 wherein the number (S) of the outer slots is equal to that of the inner slots,   wherein the outer rotor includes an outer rotor yoke and an outer permanent magnet with the number of poles P,   wherein the inner rotor includes an inner rotor yoke and an inner permanent magnet with the number of poles P, and   wherein the number of slots S and the number of poles P hold S:P=3:2N−1, where integer N is 1 or more, and a case where 2N−1 is a multiple of 3 is excluded.   
   
   
       11 . The drum type washing machine of  claim 10 , wherein the number of slots S and the number of poles P hold S:P=3:5. 
   
   
       12 . The drum type washing machine of  claim 10 , wherein at least one of the outer permanent magnet and the inner permanent magnet is embedded into an inside of the outer rotor yoke or the inner rotor yoke.