Abstract: An electric machine includes a stator lamination packet having an inner periphery defining a stator bore, a laminted screening packet with an inner periphery and lamination segments formed of magnetic material, and a slot and tooth system disposed on and connected to the inner periphery of the screening packet, the slot and tooth system being at least partly formed of nonmagnetic material and having successive slot teeth defining bar receiving slots with a slot bottom, and an air-gap winding on the inner periphery of the stator lamination packet having winding bars with winding bar sides oriented toward the stator bore, the winding bars being inserted in the bar receiving slots with a radial protrusion beyond the slot teeth.

Abstract: Apparatus for fastening an air gap winding for electric machines having a large power rating, such as turbo generators, including a stator lamination stack formed of magnetic lamination segments, a mounting body formed of non-magnetic lamination segments having teeth with slots formed therebetween, the mounting body being welded at a seam to the stator lamination stack to form common lamination segments, winding bars being held in the slots and extending beyond the teeth into the mechanical air gap, pressure strips disposed in longitudinal direction of the slots pretensioning the winding bars in radial direction, clamping screws being radially disposed in the vicinity of the slot teeth and holding the pressure strips, and abutments anchoring the clamping screws in the vicinity of the stator lamination stack.

Abstract: Apparatus for cooling lamination stacks of electric machines comprising an enclosure for receiving cooling gas, the enclosure being disposable around a lamination stack and being formed with a plurality of gas inlet chambers, means for circulating cooling gas through the chambers and through a plurality of axially spaced cooling channels formed in the lamination stack, and an additional gas inlet chamber located at an end of the lamination stack for receiving the cooling gas in parallel with the plurality of chambers and for directing the cooling gas over the end of the lamination stack.