MRG Gear and Shafting Flashcards
What is the Horsepower rating of the MRG
51,500 HP
What is the functional Description of the MRG?
- Double Input - Two GTMs coupled as a prime mover to a single shaft.
- Double Reducton - Reduction occurs over 2 stages, first reduction pinion to first reducion gear; second reduction pinion to second reduction gear, also known as the “bull gear”.
- Double Helical - The gear teeth are machined in a
“V” pattern, which reduces noise and axial thrust and provides a smoother mesh at high speeds. - Articulated - The first reduction gear is coupled to the second reduction pinion via a quill shaft and flexible coupling
- Single Ouptut - each MRG drives a single shaft
- Locked Train - Term applied to dual torque path gear design, which uses two intermediate shafts for each high speed input path. No gear is permitted independent rotational movement
What is the reduction gear ratio?
21.35:1
How many bearings?
30: Four Thrust bearings, 26 journal bearings
What is required to engage the PT Brake?
Npt 85 PSIG
What is brake mode?
Used to stop the shaft in an emergency by forcing the GTMs to idle and applying the PT Brake, which disengages the Triple S clutch
What is the purpose of the Dehumidifer
Keeps Humidity below 35% when MRG is secured
When does the SSS Clutch engage
When input shaft speed is equal to or greater than output shaft speed
How is the Shaft seal lubricated?
Sea Water
If shaft seal fails, what can be used
Inflatable boot which uses LP Air or CO2 Bottles
MRG Most Remote Bearing
NR 22, Outboard 1st red pinion bearing
Max Brg Temp, Local Oil Temp
180F
Bearing High Temp Alarm
20F above full power trial max
Power Turbine Brake rating
Stops PT in 10 sec at max 2200 RPM
PT Brake booster rating
83 PSIG in, 747 PSIG out to caliper
