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Advanced gearbox technologyAn advanced 13,000 HP, counterrotating (CR) gearbox was designed and successfully tested to provide a technology base for future designs of geared propfan propulsion systems for both commercial and military aircraft. The advanced technology CR gearbox was designed for high efficiency, low weight, long life, and improved maintainability. The differential planetary CR gearbox features double helical gears, double row cylindrical roller bearings integral with planet gears, tapered roller prop support bearings, and a flexible ring gear and diaphragm to provide load sharing. A new Allison propfan back-to-back gearbox test facility was constructed. Extensive rotating and stationary instrumentation was used to measure temperature, strain, vibration, deflection and efficiency under representative flight operating conditions. The tests verified smooth, efficient gearbox operation. The highly-instrumented advanced CR gearbox was successfully tested to design speed and power (13,000 HP), and to a 115 percent overspeed condition. Measured CR gearbox efficiency was 99.3 percent at the design point based on heat loss to the oil. Tests demonstrated low vibration characteristics of double helical gearing, proper gear tooth load sharing, low stress levels, and the high load capacity of the prop tapered roller bearings. Applied external prop loads did not significantly affect gearbox temperature, vibration, or stress levels. Gearbox hardware was in excellent condition after the tests with no indication of distress.
Document ID
19900014958
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Anderson, N. E.
(General Motors Corp. Indianapolis, IN, United States)
Cedoz, R. W.
(General Motors Corp. Indianapolis, IN, United States)
Salama, E. E.
(General Motors Corp. Indianapolis, IN, United States)
Wagner, D. A.
(General Motors Corp. Indianapolis, IN, United States)
Date Acquired
September 6, 2013
Publication Date
June 1, 1987
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
NASA-CR-179625
EDR-12909
NAS 1.26:179625
Meeting Information
Meeting: AIAA/SAE/ASME/ASEE 23rd Joint Propulsion Conference
Location: San Diego, CA
Country: United States
Start Date: June 1, 1987
Accession Number
90N24274
Funding Number(s)
CONTRACT_GRANT: NAS3-24341
PROJECT: RTOP 535-03-22
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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