Bi-modal turbine assembly and starter / drive turbine system employing the same
First Claim
1. A bi-modal turbine assembly for use in conjunction with a gas turbine engine, the bi-modal turbine assembly comprising:
- a housing assembly having a flow passage therethrough;
a turbine wheel rotatably mounted in the housing assembly and positioned so as to be driven by pressurized air flowing through the flow passage;
an output shaft rotatably mounted in the housing assembly;
a first gear train disposed in the housing assembly and having a first gear ratio selected such that the bi-modal turbine assembly produces peak output power between a first engine speed generally indicative of engine lightoff and a second engine speed generally indicative of flight idle;
a second gear train disposed in the housing assembly and having a second gear ratio less than the first gear ratio and selected such that the bi-modal turbine assembly produces peak output power between the second engine speed generally indicative of flight idle and a third engine speed generally indicative of engine cruise; and
a switching device disposed in the housing assembly and configured to mechanically couple;
(i) the first gear train between the turbine wheel and the output shaft in a first operational mode, and (ii) the second gear train between the turbine wheel and the output shaft in a second operational mode.
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Accused Products
Abstract
A bi-modal turbine assembly is provided for use in conjunction with a gas turbine engine. In one embodiment, the bi-modal turbine assembly includes a housing assembly having a flow passage therethrough, a turbine wheel rotatably mounted in the housing assembly and positioned so as to be driven by pressurized air flowing through the flow passage, an output shaft rotatably mounted in the housing assembly, and first and second gear trains disposed in the housing assembly. A switching device is also disposed in the housing assembly and configured to mechanically couple: (i) the first gear train between the turbine wheel and the output shaft in a first operational mode, and (ii) the second gear train between the turbine wheel and the output shaft in a second operational mode.
57 Citations
11 Claims
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1. A bi-modal turbine assembly for use in conjunction with a gas turbine engine, the bi-modal turbine assembly comprising:
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a housing assembly having a flow passage therethrough; a turbine wheel rotatably mounted in the housing assembly and positioned so as to be driven by pressurized air flowing through the flow passage; an output shaft rotatably mounted in the housing assembly; a first gear train disposed in the housing assembly and having a first gear ratio selected such that the bi-modal turbine assembly produces peak output power between a first engine speed generally indicative of engine lightoff and a second engine speed generally indicative of flight idle; a second gear train disposed in the housing assembly and having a second gear ratio less than the first gear ratio and selected such that the bi-modal turbine assembly produces peak output power between the second engine speed generally indicative of flight idle and a third engine speed generally indicative of engine cruise; and a switching device disposed in the housing assembly and configured to mechanically couple;
(i) the first gear train between the turbine wheel and the output shaft in a first operational mode, and (ii) the second gear train between the turbine wheel and the output shaft in a second operational mode. - View Dependent Claims (2)
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3. A bi-modal turbine assembly for use in conjunction with a gas turbine engine, the bi-modal turbine assembly comprising:
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a housing assembly having a flow passage therethrough; a turbine wheel rotatably mounted in the housing assembly and positioned so as to be driven by pressurized air flowing through the flow passage; an output shaft rotatably mounted in the housing assembly; a first gear train disposed in the housing assembly and having a first gear ratio selected such that the bi-modal turbine assembly produces peak output power between approximately 10% and approximately 50% of the maximum speed of the gas turbine engine; a second gear train disposed in the housing assembly and having a second gear ratio less than the first gear ratio and selected such that the bi-modal turbine assembly produces peak output power between approximately 60% and approximately 100% of the maximum speed of the gas turbine engine; and a switching device disposed in the housing assembly and configured to mechanically couple;
(i) the first gear train between the turbine wheel and the output shaft in a first operational mode, and (ii) the second gear train between the turbine wheel and the output shaft in a second operational mode. - View Dependent Claims (4)
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5. A starter/drive turbine (SDT) system for use in conjunction with a gas turbine engine deployed on an aircraft, the SDT system comprising:
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a bi-modal turbine assembly, comprising; a housing assembly having a flow passage therethrough; a turbine wheel rotatably mounted in the housing assembly and positioned so as to be driven by pressurized air flowing through the flow passage; an output shaft rotatably mounted in the housing assembly; a first gear train disposed in the housing assembly; a second gear train disposed in the housing assembly; and a switching device disposed in the housing assembly and configured to selectively couple the first gear train and the second gear train between the turbine wheel and the output shaft; a controller operatively coupled to the switching device and configured to cause the switching device to mechanically couple;
(i) the first gear train between the turbine wheel and the output shaft in a Start Mode, and (ii) the second gear train between the turbine wheel and the output shaft in an Energy Conservation Mode; anda sensor configured to monitor a characteristic indicative of the speed of the gas turbine engine, the controller operatively coupled to the sensor and configured to transition from Start Mode to Energy Conservation Mode when the speed of the gas turbine engine exceeds a predetermined engine speed threshold between approximately 50% and approximately 100% of the maximum speed of the gas turbine engine. - View Dependent Claims (6, 7, 8, 9, 10, 11)
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Specification