Armature as well as an electric motor

PROBLEM TO BE SOLVED: To solve the following problem associated with a technique in which when a conventional armature is applied to a high-speed rotation motor, rotation unbalance is adjusted by cutting an armature core: magnetic balance is lost and as a result, the life is shortened by rectification failure in a brush, motor efficiency is degraded by rectification failure, and vibration and noise are produced. SOLUTION: With respect to coil disturbance at each winding step, the number of turns n 1 of a first coil and the number of turns n 2 of a second coil are determined so that when (G 1 ×n 1 )+(G 2 ×n 2 ) fluctuates, the maximum value ≤228 is satisfied, where G 1 is a barycentric position of a first coil group and G 2 is a barycentric position of a second coil group, each of the barycentric positions being defined by a certain expression when a winding coefficient of the first coil is defined as k 1 and a winding coefficient of the second coil is defined as k 2 . COPYRIGHT: (C)2011,JPO&INPIT