GB952752A - A stator winding in an electric machine - Google Patents

Abstract

952,752. Dynamo-electric machines. SIEMENS-SCHUCKERTWERKE A.G. July 31, 1961 [July 30, 1960; June 19, 1961], No. 27772/61. Heading H2A. In a stator winding for a dynamo-electric machine in which the conductor bar lying within each slot comprises a plurality of individual hollow conductors which are transposed within the slot and carrying a fluid coolant during operation of the machine, the winding length for each phase comprises a plurality of sections each consisting of a plurality of turns connected in series so that both the electric current and the coolant flow in succession through the turns, successive sections being connected at their ends by end caps fitting over the ends of adjacent conductor bars in successive sections, the end caps being provided with branches for conveying the coolant to or from the sections and also providing the only electrical connections between the individual hollow conductors, these being insulated from each other along their whole length between section ends to prevent the occurrence of losses due to circulating currents. Fig. 1 shows a winding length for one phase, this consisting of two sections A, B consisting respectively of turns 1, 2 and turns 3, 4. Each turn consists of two conductor bars, e.g. 1 o and 1 u which are respectively upper and lower bars in their respective slots. Each bar, shown in section in Fig. 2, consists of a plurality of indivdual hollow conductors, which are transposed within the slot, surrounded by an insulating sleeve h and respectively insulated from each other. End caps, Fig. 5, serving as headers are arranged over the ends of successive bars, for example bars 2 u and 3 o , at section ends only. The coolant is supplied through an insulating duct 14 and the bars are conductively connected to each other by the material of the cap and also by an additional sleeve 10; at the same time the individual conductors of each conductor bar are all connected conductively together. Other connections between successive bars, i.e. those connections occurring between the ends of any one section, are effected as shown in Fig. 4. In this Figure the individual conductors of conductor bar 1 o are shown as 1 o1 -1 o5 and those of conductor bar 1 u are shown as 1 U1 -1 U5 , the indivdual conductors being connected by individual U-shaped tube connectors r 1 -r 5 which constitute the respective end winding. In an alternative arrangement, Fig. 8, the end winding between bars 1 U and 2 0 is shown as provided with a twist in two planes so that upper conductors of bar 1u remain the upper conductors in bar 2 o . Hence, as described in Specification 952,751, a parastic E.M.F. induced in any one conductor of the bar 1 U is compensated by a substantially equal E.M.F. developed in a similarly disposed conductor in the bar 2 o . In this arrangement the individual conductors are shown soldered together at point t; the connection may be effected by short pushed-on lengths of tube at this point, Fig. 9 (not shown).