Drive Train Flashcards
What is the purpose of the drivetrain?
Transmits rpm from the engine to the MR and TR
Np RPM
32,183 RPM
Torquemeter Gear RPM
10,528 RPM
Power Output Shaft RPM
6,317 RPM
MR RPM
413 RPM
~TR RPM
2,497 RPM
Transmission RPM Ratio
15.29:1 Reducing
TR Gearbox Ratio
2.53:1 Reducing
What does the drive train consist of?
Mast, transmission, main driveline (Kaflex), freewheeling unit, engine accessory gear box, TR driveshaft, oil cooler blower assembly, TR gear box
Describe the mast
Hollow steel shaft
3 sets of splines: upper, swashplate, lower
2 threaded areas: upper and lower
Attached to transmission via locking plate and nut
What is the purpose of the Main Drive Shaft and how does it fulfill that purpose.
The Kaflex provides a flexible connection between freewheeling unit and transmission
- allows for smooth torque transfer when the freewheeling unit and transmission are not aligned
Flexibility is provided by 3 rectangular plate sets in each coupling.
- each plate flexes as torque is carried axially through the straight parts of each plate
- provides for both angular misalignment and length changes as the transmission moves on its mounts
Describe how the freewheeling unit works
Engine power - outer race - engaged sprags - inner race - main driveline (Kaflex)/TR driveline via flex coupling and splined adapter.
Describe the Tail Rotor Drivetrain.
7 flexible segments
- Steel - between engine accessory gearbox and aft firewall, has the AC compressor on it
- Steel - after firewall, has the oil cooler blower on it
3-7. Aluminum shafts of equal length
- Supported by 6 hanger bearings that assist in maintaining driveshaft alignment
- Segments connected by 8 Thomas coupling disc packs, each with 9-12 steel plates (plates turned 90 to increase strength and flexibility
Describe the TR gearbox
Magnesium housing gearbox attached to the tail boom by 4 studs and 2 alignment pins.
90 degree change using 2 spiral bevel gears
Speed reducing ratio 2.53:1
RPM ~2,497
How many Chip detectors are on the drive train system and where are they?
6 total
- In the TR Gearbox
- In the Engine Accessory Gearbox
- In the Transmission system: 1 in the freewheeling unit, 2 in the transmission case