GB848520A - Improvements in or relating to dynamo electric machines - Google Patents

Abstract

848,520. Cooling dynamo-electric machines. GENERAL ELECTRIC CO. Ltd. Jan. 14, 1958 [Jan. 25, 1957], No. 2811/57. Class 35. A dynamo-electric machine such as an alternator of large output has a stator 3 within whose core are provided axial ducts 11 extending the length of the core and through which cooling fluid is arranged to flow from one core end to the other, and one or more radial cooling ducts 12 at least at the end of the core forming the exit for the axial ducts 11 and through at least a part of which radial ducts 12 fluid is arranged to flow independently of that in the axial ducts 11, the part of the core intermediate the core ends having no radial cooling ducts. As shown, the radial ducts are at both core ends and one discharges in addition fluid from certain of the axial ducts 11; they are formed by H cross-section spacing-bars disposed radially between adjacent layers of sector-shaped core laminations. The fluid is hydrogen which is drawn by a centrifugal fan 6 through a cooler 5 and baffle holes 16 which are blanked off or exposed to obtain the correct gas distribution in parallel circuits through the rotor, the rotor to stator air gap, and the stator 3. The gas enters the stator radial ducts 12 via a transfer port 13 and discharges into the air gap,. and enters and mainly leaves the axial ducts 11 through core lamination clamping means 7 comprising a ring having ribs 8 defining spaces 9, and fingers 10. In a modification, not shown, the radial ducts are formed by sectorshaped casing pads disposed between stator core end laminations and/or between the end laminations and the clamping means 7; each pad has an inlet and outlet for connection to a water cooling system which may be shunted across that supplying cooling water to the cooler 5.