Patent ID: 7141898
Filing Date: 2006-11-28
Classification: H02K

Abstract:
1. A generator comprising: a rotor and stator with a gap between the rotor and the stator, the gap having ends; baffles at the ends of the gap; a substantially hermetically sealed enclosure filled with a gaseous coolant at superatmospheric pressure and including a coolant receiving region, the rotor and the stator positioned in the enclosure, and wherein no fan is located in the enclosure; the stator including a core, cooling ducts in the stator core, and windings which form a winding overhang at each end of the stator, the rotor including cooling channels; wherein, when the generator is operating, and when the generator is in fluid communication with a cooling apparatus, gaseous coolant flows in a circuit from the cooling apparatus at least partially through the winding overhangs, then through cooling channels in the rotor, then into said gap, then through the cooling ducts in the stator core into the coolant receiving region, and then through the cooling apparatus, the baffles configured and arranged to both inhibit escape of the gaseous coolant from the ends of said gap and inhibit entry of the gaseous coolant into the gap through the gap ends, the flow of gaseous coolant around said cooling circuit being caused solely by centrifugal force acting on the gaseous coolant in the cooling channels of the rotor when said rotor rotates.