seen from fig8 a start position of the three magnets a b c is represented by positions 36 37 and 38 which are themselves offset from one another by 45 u00b0 as the magnets a b c are synchronously driven along with the other magnets around the stator the various illustrations show each magnet a b c advanced by 45 u00b0 as represented by the positions 39 40 41 42 43 44 45 46 47 and 48 49 50 similarly it can be seen from fig9 a start position of the three magnets d e f is represented by positions 51 52 and 53 which are themselves offset from one another by 45 u00b0 as the magnets d e f are synchronously driven along with the other magnets around the stator the various illustrations show each magnet d e f advanced by 45 u00b0 as represented by the positions 54 55 56 57 58 59 60 61 62 and 63 64 65 fig9 further shows that each pole in the same pole pair in the individual permanent magnet rotors is insulated from the other by a shield made up of for example mu metal sheets 66 and 67 with a ferrous layer 68 sandwiched therebetween as will be described in greater detail hereinafter with reference to fig1 as previously set forth armature inserts 7 can be provided with permanent magnets made with bipolar magnetic bodies having two poles of the same magnetic polarity exposed on each end.