Enhanced Air Turbine Starter Clutch Design

Document Number: 942104

Date Published: October 1994

Author(s):
Andy Krochmalny - AlliedSignal, Inc.
Peter J. Louden - Boeing Commercial Airplane Group

Abstract:
Since introduction into service, the B737-300 starter has been susceptible to clutch damage. At the onset of the problem, a team was formed to identify the causes of clutch damage and shear shaft failures and to define a corrective action. Several in- service airplanes were equipped with recording instrumentation, and data from over 10,000 start cycles was recorded. It was noted that large pneumatic duct pressure fluctuations from a variety of causes played an important role in the reason for the starter reliability problem. After understanding the problem, a design improvement program was launched to replace the current pawl-and-ratchet clutch with an inner-race overrunning sprag clutch that would be capable of withstanding resulting duct pressure fluctuations.

File Size: 576K
Product Status: In Stock

See other papers presented at Aerotech Conference & Exposition, October 1994, San Diego, CA, USA, Session: Aerotech Conference & Exposition

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