Abstract: A rotor assembly is provided in which a permanent magnet rotor is used in conjunction with a wound stator member. A containment fixture or cup, receives one or more permanent magnets. The containment fixture has an annular end wall, a circumferential side wall and a circumferential lip. The lip serves to provide a high degree of rigidity and rotational stability to the containment fixture. The magnets abut both the lip and the side wall and the rigidity of the fixture prevents flexing and breaking of the magnets even at high rotational speeds.

Abstract: A stator assembly for a d.c. electric motor/generator has a pair of permanent magnet segments located on the interior surface of the yoke. The magnet segments are held in place by a pair of wedges which are attached to the yoke. The wedges are tapered inwardly and the magnet segments are tapered outwardly to hold the magnet segments in place against the interior surface of the yoke. The tapered magnet segments also reduce cogging torques produced on the armature due to the gradual fall off of the magnetic flux at the tapered side edges of the magnet segments.