Air-start assembly and method

• US 5,349,814 A
• Filed: 02/03/1993
• Issued: 09/27/1994
• Est. Priority Date: 02/03/1993
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Ciokajlo, John J., O'Brien, Michael T.
• Primary Examiner(s): Bertsch, Richard A.
• Assistant Examiner(s): WICKER, WILLIAM
• Application Number:
  US08/012,664
• Time in Patent Office: 601 Days
• Field of Search: 60/39.091, 60/39.142, 60/226.1, 60/39.163
• US Class Current: 60/226.1
• CPC Class Codes: F02C 7/262 Restarting after flame-out
• CPC Class Codes: F02C 7/268 Starting drives for the rotor , acting directly on the rotor of the gas turbine to be started
• CPC Class Codes: F02C 7/275 Mechanical drives
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)

Abstract

A method and assembly are effective for air-starting an aircraft gas turbine engine having a fan powered by a low pressure turbine through a first shaft, and a compressor powered by a high pressure turbine through a second shaft disposed coaxially therewith. A gear train is selectively operatively joined between the first and second shafts by selectively engaging a first clutch for transmitting torque through the first clutch only in one direction from the first shaft to the second shaft when the fan is windmilling for driving the second shaft to allow an air-start of the gas turbine engine during flight. In a preferred embodiment, a second clutch is operatively joined to the gear train and is selectively engageable at speeds of the second shaft below a predetermined release speed, and disengageable at the release speed and above for disconnecting the air-start assembly once the engine has been started.

Claims