Magneto-generator
A magneto-generator capable of suppressing temperature rise of an armature winding and ensuring an improved electricity generation efficiency includes a flywheel having a cylindrical peripheral wall formed with a flat bottom wall at one end thereof, a plurality of magnets disposed on and along an inner peripheral surface of the cylindrical peripheral wall, a generator coil disposed internally of the flywheel in opposition to the magnets for generating electricity under electromagnetic induction taking place between the magnets and the generator coil, ventilating through-holes formed in a joined portion of the cylindrical peripheral wall and the flat bottom wall so as to extend partially through both of them, and upstanding fins disposed on the bottom wall for generating forced air flows from interior to exterior of the flywheel through the ventilating through-holes upon rotation of the flywheel.
1. A magneto-generator, comprising:
a flywheel having a cylindrical peripheral wall and a flat bottom wall which closes said cylindrical peripheral wall at one end thereof;
a plurality of magnets disposed on and along an inner peripheral surface of said cylindrical peripheral wall of said flywheel;
a generator coil disposed internally of said flywheel in opposition to said magnets for generating electricity under the action of electromagnetic induction taking place between said magnets and said generator coil;
ventilating through-holes formed in a joined portion between said cylindrical peripheral wall and said flat bottom wall of said flywheel so as to extend in continuation partially through both said cylindrical peripheral wall and said flat bottom wall; and
a plurality of upstanding fins disposed on said flat bottom wall for generating forced air currents flowing from interior to exterior of said flywheel by way of said ventilating through-holes upon rotation of said flywheel to thereby cool said generator coil.
2. A magneto-generator according to claim 1 , further comprising:
a magnet protecting resin filled in a peripheral space surrounding said magnets for fixedly securing said magnets relative to said flywheel and protecting said magnets,
wherein said fins are formed concurrently with formation of said magnet protecting resin.
3. A magneto-generator according to claim 2 ,
wherein said magnet protecting resin structure is formed with recesses for accommodating therein said magnets, respectively, when said magnet protecting resin structure is formed through molding, and said magnet protecting resin structure is mounted internally of said flywheel after said magnets have been mounted within said recesses, respectively.
4. A magneto-generator according to claim 1 ,
wherein said fin is disposed with a predetermined angle of inclination relative to said inner peripheral surface of said flywheel.
5. A magneto-generator according to claim 1 ,
wherein said fin presents a concavely curved side surface in a direction in which said flywheel rotates.
6. A magneto-generator according to claim 1 ,
wherein said plurality of ventilating through-holes and said plurality of fins are disposed each in an annular array with said ventilating through-holes and said fins alternating with each other.