slots extend the length of the rotor body and annular retaining rings 22 cap both ends of the rotor body the retaining rings are supported at one end by the rotor body see fig2 adjacent the retaining rings are fans 26 that cool the retaining rings and other rotor components as will be appreciated from fig2 the retaining rings 22 slide over the end of the rotor body and are attached to the rotor body by a conventional shrink fit process the end turns 28 are enclosed by the retaining rings which thus prevent radially outward movement of the end turns by centrifugal forces generated by the rotor the end turns extend circumferentially about the rotor and are axially spaced from one another while the turns between the ends lie parallel to the rotor axis and are circumferentially spaced from each other in each case the spacing between adjacent coils is maintained by a predetermined distance by means of blocks 30 as shown in fig3 in fig4 the spacer blocks 30 are shown at axially spaced locations between the end turns of the windings 28 of the coils note that the end turns are vertically aligned with parallel sides typical of rotor configurations which employ parallel sided slots the individual turns as they appear in the parallel sided slots of the rotor are shown in fig6 for rotors which have tapered slots however the end turns 29 typically appear as shown in fig5 and the turns 29 as they appear in the tapered rotor slots are shown in fig7 note that because of the tapered configuration of the rotor slots the end turns require that the spacer blocks 32 be wider at the radially inboard end closest to the rotor as indicated at s 2 than they are.