15.17 Turboshaft Enigines Flashcards
what is a turbo shaft engine optimised to create?
shaft power, not thrust
how may the shaft be driven in a turbo shaft engine ?
coupled directly to the turbine or driven by its own free turbine located in the exhaust stream
how does the free turbine rotate ?
independently
what is a turbo shaft’s engine output measured in ?
shaft horse power
what are the two major part assemblies of a turboshaft engine ?
-gas generator
-power section
what does the gas generator section comprise of?
Compressor, combustion chambers, igniters, nozzles, and one or more sections of the turbines
what does the power section comprise of ?
additional stages of turbines, gear reduction system, and the shaft output
where might turboshaft engines be used?
where is sustained high power output ,high reliability, small size and light weight is needed such as helicopter engines and APU’s
why are Drive systems fitted turboshaft engines ?
to transfer the power produced within the engine
what are the two components used to reduce transmission speeds?
- reduction gearbox
- main rotor gearbox
when an aircraft uses two turboshaft engines, What must be fitted to stop one engine from driving the other?
a free wheel which automatically disconnects the slower engine
what is a free wheel also known as ?
a sprag clutch
what is the purpose of a universal joint being fitted to the output shaft?
it ensures driveshaft alignment between the engine and the main rotor gearbox.
and it also ensures the transmission of only the engines torque
what is the purpose of reduction gearing?
to slow the output shaft’s speed down
why is a universal joint connection provided on a turbo shaft engine ?
so that there is adequate movement of the transmission
