Patent ID: 8633626
Filing Date: 2014-01-21
Classification: H02K

Abstract:
1. A DC motor comprising: a yoke; a magnet that is provided along the inner surface of the yoke and has four or more of magnet poles in the circumferential direction; an armature that is arranged to face the magnet and composed of a core and a coil; a shaft that is fixed by being inserted along the rotating shaft of the armature; and a commutator that is attached to the shaft so as to be coaxial with the armature; wherein the magnet is formed of a material with a maximum energy product BHmax of 3 to 6 MGOe, and wherein when the thickness of the magnet in the radial direction of the armature is indicated by T [mm] and the outer diameter of the core is indicated by d [mm], the ratio T/d of the thickness T of the magnet to the outer diameter d of the core is 0.16 or more.