Patent ID: 8829752

Claim:
A synchronous permanent magnet machine, comprising: a permanent magnet arrangement for producing a magnetic field having a flux density distribution that is approximately sinusoidal, the permanent magnet arrangement comprising: a permanent magnet pole comprising both low and high energy-product magnets, wherein (i) the permanent magnet pole includes a low energy-product magnet and a high energy-product magnet that have different directions of magnetization, or (ii) a disposition of low/high energy-product magnets within the permanent magnet pole is asymmetric with respect to a central region of the permanent magnet pole, and wherein the main high energy-product magnet has been shaped so that a height of the main high energy-product magnet remote from the side low energy-product magnet is reduced as compared to a height of the main high energy-product magnet adjacent to the side low energy-product magnet.