GB696760A - Improvements in or relating to windings for rotors - Google Patents

Abstract

696,760. Conductors for dynamo-electric machines. PARSONS & CO., Ltd., C. A. March 19, 1951 [May 24, 1950], No. 13052/50. Class 35. In order to reduce the temperature gradient of the slot of an alternator rotor the latter is wound with conductor strips having their flat surface substantially parallel and approximately equal in radial depth to the central radial plane of the slot. Fig. 1 shows a slot 1 accommodating a number of turns 6 of copper or aluminium strip arranged parallel to the radial plane of the slot. At the base of the slot there is a ventilating channel 5 and on top of the slot below the wedge 3 there is a damping winding 4. The turns 6 are separated by insulation 7. In a modification shown in Fig. 2, the conductors 6 are tapered in section to produce a wedging action at high speeds. In a further modification, the turns 6 are insulated in pairs and each pair is surrounded by a metal sheath 8, Fig. 3 (not shown) to dissipate heat. Fig. 4 shows how the turns 9 forming the winding are built up and joined at their end portions at 11. These joints are effected by welding, riveting, bolting or similar means. Fig. 5 shows how the ends of the coils are secured by insulated bolts 14 which pass through the coils, the bolts also secure the end supporting ring 13 against the coil retaining ring 12. Alternatively, additional separate bolts 16 are employed to brace the coil ends. Fig. 9 shows the bolts 14 arranged to pass underneath the coils 9 and not through them and therefore the conductors are suitably cut at their inner part to accommodate the bolts 14. The conductors can also be partly aluminium and partly copper. The end coils may be modified in section so as to reduce their width and lessen the weight of the windings supported by the rotor coil retaining ring.