A number of embodiments of rotating electrical machines using permanent
magnets wherein the cogging torque is substantially reduced as are
vibrations caused by magnetic flux variations. This is accomplished by
disposing the coil windings in equal circumferential spacing and
disposing the associated permanent magnets in non-symmetrical
relationship so that the gaps between some of the magnets are different.
In addition, the coil windings are such that no two coils of any phase
are immediately adjacent each other in a circumferential direction. A
method for calculating the optimum spacing is also disclosed.