초록 ▼

A double rotor-type brushless direct-current motor includes first and second annular-shaped rotors each having a plurality of north and south-polar magnets which are alternately disposed at a predetermined distance; a rotating shaft connected to a central portion of the rotors thorough a bushing; up

A double rotor-type brushless direct-current motor includes first and second annular-shaped rotors each having a plurality of north and south-polar magnets which are alternately disposed at a predetermined distance; a rotating shaft connected to a central portion of the rotors thorough a bushing; upper and lower cases receiving and rotatably supporting opposite ends of the rotating shaft; an annular-shaped stator having a plurality of stator coils supported by a molding filler to apply electromagnetic force to the first and second rotors in an opposite direction to each other, the stator being mounted between the first and second rotors at a predetermined clearance; and a control printed circuit board for applying a driving current with respect to the stator, the control printed circuit board being mounted one of the upper and lower cases; wherein the upper and lower cases, the control printed circuit board, the first and second rotors have a plurality of ventilating holes for circulating air from the outer side of the motor to the inside of the motor.

대표청구항 ▼

[ What is claimed is:] [1.] A double rotor/single stator-type brushless direct-current motor, comprising:first and second annular-shaped rotors arranged at a predetermined distance from each other, each of said first and second rotors having a plurality of alternatively arranged north-polar and sout

[ What is claimed is:] [1.] A double rotor/single stator-type brushless direct-current motor, comprising:first and second annular-shaped rotors arranged at a predetermined distance from each other, each of said first and second rotors having a plurality of alternatively arranged north-polar and south polar magnets;a rotating shaft connected to a central portion of the rotors through a bushing, said shaft having an axis;upper and lower cases rotatably supporting the rotating shaft; andelectromagnetic drive and axial vibration preventing means for generating rotational drive and preventing axial vibration associated with the rotational drive generation, said electromagnetic drive and axial vibration preventing means comprising:a coreless type stator having a plurality of stator coils for applying electromagnetic force to the first and second rotors, each of said coils being wound around a bobbin, said stator being mounted between the first and second rotors and formed in an annular shape by molding filler, an outer circumference of said stator being supported between said upper and lower cases, the coils of said stator having windings through which an electric current flows to produce magnetic fluxes which have opposite axial polarity orientations and produce electromagnetic forces which act in opposite directions and which are applied to said first and second rotors in opposite directions when the magnets of said first and second rotors which are respectively exposed thereto have the same polarities, and so that the coils respectively produce magnetic fluxes which have the same axial polarity orientation and produce electromagnetic forces which act in opposite directions when the magnets of said first and second rotors which are respectively exposed thereto have opposite polarities,wherein said stator comprises:a stator body for supporting the wound coils in an annular shape and sealing an exposed portion of the wound coils, anda printed circuit board mounted directly against one face of the stator body for electrically interconnecting the coils thereon.