Patent ID: 9601950
Date: 2017-03-21
CPC Classifications: H02K

Claim:
1. A permanent magnet motor, wherein a relationship of mN≠K is satisfied with respect to an integer m, where the pole number of a rotor is K and the number of partial iron cores of a stator iron core of a stator is N, and N values of r(θ+(i−1)×360°/N), . . . , r(θ+(N−1)×360°/N), with respect to i=1 to N, are set to be equal so that the absolute value of the difference between any two values of the N values, due to a clearance for fitting the partial iron cores and manufacturing deviations, becomes equal to or smaller than a predetermined value, where r(θ) is an inner radius defined as, on a plane perpendicular to a rotary shaft of the rotor, a distance from the center of the rotary shaft to a point on a surface of the stator iron core facing to the rotor at which an angle from a fitting portion of the partial iron core is θ on the perpendicular plane, θ taking a value of 0 to 360°/N, wherein a parameter calculated by the following expression (1) is set to be equal to or smaller than a predetermined value, wherein ΔM is the average value of Δmax with respect to the axial direction height of the stator iron core, Δmax being the maximum value, with respect to θ, of the absolute value of the difference between any two values among the N values of r(θ+(i−1)×360°/N), . . . , r(θ+(N−1)×360°/N), with respect to i=1 to N, wherein Lm is the thickness (m) of the permanent magnet, μr is a recoil permeability, g is an air gap length (m), and Br is the residual magnetic flux density (T) of the permanent magnet, and wherein the predetermined value for the parameter is 2.2×10