GB660942A - Improvements in and relating to dynamoelectric machines - Google Patents

Abstract

660,942. Cores for dynamo-electric machines. BRITISH THOMSON-HOUSTON CO., Ltd. June 20, 1949 [June 23, 1948], No. 16342/49. Class 35. In order to minimize the vibrations on the support of a dynamo-electric machine caused by the rotating field, stator laminations 14 are secured by longitudinal key-bars 15, the ends of which are in turn supported by longitudinal spring bars 16 through rings 26, the bars 16 are carried by web plates 20, 21, 22 and pass freely through web-plates 24, 25. The spring-bars 16 are arranged in two sets, one for each axial half of the machine, and the ends of each spring-bar are welded to the respective end-plate 19, to the web 20 or 22 and to the centre web 21 which connects the respective inner ends of the bars 16. The bars 16 are preferably made of two diameters as indicated by 16a, 16b to compensate for unequal axial distance spanned by the supporting rings 26. The web plates which serve to support the laminations and to divide the cooling air flow are either split as 20, 22 or cut back at their inner bores as 21, 24, 25, so that they do form a rigid mechanical connection from the casing 18 to the laminations 14. The required resilient mounting of the stator core is achieved by supporting entirely the latter from the centres of the spans of the spring-bars 16 by the webplates 20, 21, 22. Fig. 3 shows how the webplate 24 is holed to allow the spring-bar 16 to pass freely through it. Stop-collars 29 may be welded to the inner surface of the plate 24 so as to separate the bar 16 from the latter by a predetermined clearance. The similar webplate 25 is holed as the plate 24. Air seals 23, 28 of resilient packing material are respectively provided at the splits of the web-plates 20, 22 and at the junction of ring 27 and plate 24 (or 25). An air cooler may be provided below, at the side or on top of the machine.