12.04 Transmission Flashcards
(19 cards)
Two main tasks of transmission?
Reduce speed and reduce torque
What RPM does the main rotor spin at?
150-400 RPM
Engine output RPM?
6000-23000 RPM
Tail rotor RPM?
1000-5000 RPM
What gears do the main module of the MGB?
Epicyclic gears (sun and planet gears)
What do free wheel units do?
Stop the MGB driving the engine
What are the 3 angles that an IGB changes drive to?
42,50 and 90 degrees
Why must engines be disconnected during start?
Due to the high inertia of spinning the rotor the must be disconnected
What is the difference in clutches position between GTE and piston engines?
GTE (mounted vertically)
Piston (mounted horizontally)
Are free power turbines connected to the main gear box?
No they are not
If the clutch doesn’t engage within a few seconds it called?
Clutch slipping
How are manual clutches operated in helicopters?
Pilot engages a mechanical lever which actuates a belt tightener which connects drive
How many free wheel units are there on a helicopter?
Found on all helicopters and one per engine
Two types of free wheel units?
Sprag unit
Ratchet type
Which freewheel unit is the most common?
Sprag unit
Where are rotor breaks usually installed?
On the drive input or the tail rotor output
What connects drive shafts together?
Connected with flex couplings
How are elastomeric bearings connected to aircraft?
They are connected via hangers
What are vibration dampers when it comes to driveshafts?
They have a rubber wear pad that keeps the driveshaft within safe parameters
