Integral composite nozzle-shield assembly for a gas-cooled dynamoelectric machine
First Claim
1. In combination with a dynamoelectric machine having a stator including a stator core, a rotor disposed within said core and defining a gas gap with said core, a gas cooler, and a fan having a plurality of blades attached to said rotor for circulating coolant gas through said dynamoelectric machine, the improvement comprising an integral composite nozzle-shield assembly for guiding the flow of coolant gas between said cooler and said fan, said nozzle-shield assembly including:
- a pair of 180-degree arcuate sections of non-electrically conductive non-magnetic material;
means for connecting the outer edge portion of each of said sections to said stator;
means for interconnecting said 180-degree arcuate sections along radial joints;
a rub strip within an annular recess in an inner edge portion of each of said arcuate sections and having a serrated surface, said serrated surface adapted to provide, when said arcuate sections are mounted in close proximity to said fan blades, a labyrinth seal to minimize leakage of coolant gas between said rub strip and said fan blades.
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Accused Products
Abstract
An integral nozzle-shield assembly for a gas-cooled dynamoelectric machine such as a large turbine-driven generator is described. The nozzle-shield assembly is formed of a non-conductive, non-magnetic material such as molded fiberglass and resin and serves to channel hydrogen gas between a heat exchanger and a rotor-mounted fan used to pump the gas through coolant passages in the dynamoelectric machine, and the assembly also provides a labyrinth seal over the fan blade tips. In one embodiment, the nozzle-shield assembly includes two 180-degree halves whose thickness varies circumferentially and which may be installed in a generator by bolting their outer edges to a stator frame member of the generator and bolting the halves together at the two radial joints between halves using flat metal plate connectors. Use of a material such as fiberglass and resin to form an integral nozzle-shield assembly results in a structure which is not susceptible to eddy current losses or damage due to arcing, and this integral assembly is readily fabricated and easy to install in a dynamoelectric machine.
24 Citations
6 Claims
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1. In combination with a dynamoelectric machine having a stator including a stator core, a rotor disposed within said core and defining a gas gap with said core, a gas cooler, and a fan having a plurality of blades attached to said rotor for circulating coolant gas through said dynamoelectric machine, the improvement comprising an integral composite nozzle-shield assembly for guiding the flow of coolant gas between said cooler and said fan, said nozzle-shield assembly including:
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a pair of 180-degree arcuate sections of non-electrically conductive non-magnetic material; means for connecting the outer edge portion of each of said sections to said stator; means for interconnecting said 180-degree arcuate sections along radial joints; a rub strip within an annular recess in an inner edge portion of each of said arcuate sections and having a serrated surface, said serrated surface adapted to provide, when said arcuate sections are mounted in close proximity to said fan blades, a labyrinth seal to minimize leakage of coolant gas between said rub strip and said fan blades. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification