PERMANENT MAGNET TYPE ROTATING ELECTRICAL MACHINE AND ELECTRIC POWER STEERING DEVICE

摘要

It is possible to provide a permanent magnet type rotating electrical machine which can reduce a cogging torque component caused by irregularities of the rotor side. The permanent magnet type rotating electrical machine includes: a rotor having a polygonal rotor core and a plurality of permanent magnets; and a stator having a fixed core and an armature winding. When M is the number of poles, N is the number of slots, M permanent magnets are arranged in circumferential direction from the first to the M-th magnet, and hi is a positional shift amount of the i-th (i = 1, 2, ..., M) permanent magnet in the circumferential direction from reference positions at an identical distance from the rotation center in the radial direction and at an identical interval in the circumferential direction, a total of M unit vectors of the angle direction of 2pN(i-1)/M(rad) are defined. When each of the M unit vectors is multiplied by a positional shift amount hi, the total of the M vectors is smaller than the maximum value of the absolute value of the positional shift amount hi.