Abstract: The method for rewinding and electric machine includes removing the original stator bars from the slots, removing the original supports from the slots, and providing new supports into the slots, wherein the new supports defining cooling channels that extend over at least a portion of the slot, providing new stator bars into the slots.

Abstract: Gaseous coolant, preferably helium, flows from coolers 12 past the winding overhangs 7 of the stator 3, then through cooling channels in the rotor 1, then into the rotor/stator gap 4, then through cooling ducts in the stator core 6 into a coolant receiving region 11, and then through the coolers 12. The coolant flow is preferably caused solely by the rotor auto-ventilation effect.

Abstract: A lateral ripple spring 30 is inserted between an armature bar 10 and the core. Conformable material 37 occupies void space between one side surface of the bar 10 and the corresponding side surface of the slot 20 in which the bar is mounted, so as to reduce the thermal resistance between the bar and the core. Conformable material 37 may be provided on the side opposite the ripple spring 30, as shown, and/or on the same side as the ripple spring.

Abstract: In a generator with indirect cooling, the stator has a core 12 comprising mutually spaced packets of core laminations, radial ducts 11 being defined between the packets for the passage of gaseous coolant between the inner and outer peripheries of the core. The core 12 has axial slots 18 which accommodate armature bars 16, 17. The stator incorporates baffles 19 arranged in such a manner that gaseous coolant flowing radially in a radial duct 11a from one periphery of the core enters a slot 18 adjacent the duct 11a and flows in a direction along the slot 18 before entering one of the radial ducts, in which it flows radially toward the other periphery of the core. Accordingly, heat from the bars 16, 17 primarily passes directly into the flowing gaseous coolant. The radial flow may be either inwards (as shown) or outwards.

Abstract: Gaseous coolant, preferably helium, flows from coolers 12 past the winding overhangs 7 of the stator 3, then through cooling channels in the rotor 1, then into the rotor/stator gap 4, then through cooling ducts in the stator core 6 into a coolant receiving region 11, and then through the coolers 12. The coolant flow is preferably caused solely by the rotor auto-ventilation effect.