Drive System Flashcards
What is the purpose of the drive system?
Transmit engine torque to the fwd and aft main rotor heads
What two purposes do the sprag clutches serve?
Single engine flight
Autorotation
Where are the sprag clutches located?
Mix box
What is the purpose of the aft transmission?
Reduce drive speed and transmit it to the vert shaft
What is the purpose of the fwd transmission?
Reduce speed and transmit it directly to the main rotor head via an integral drive shaft
Can the forward and aft blades and rotor heads be interchanged?
No, they are similar but spin in opposite directions
What does the blower shaft do?
Conveys torque from mix box to oil cooler blower fan via a “takeoff”
Are the fwd and aft transmission oil systems together?
No, two separate systems which share the same cooler.
Which oil system is connected to the part of the blower fan that receives direct airflow?
The aft. The fwd doesn’t need direct air because it gets some of its cooling through the oil lines in the tunnel going to the fwd transmission
How many sync shafts are there?
5
4 aluminum
1 steel
Who’s is the #5 sync shaft stainless steel
To provide resistance to engine fire or catastrophic engine failure
How are the aft portions of the engines supported?
What has to be done to these shafts after a transmission replacement?
Torque tubes
The shafts from the engine need to be dynamically balanced.
What is a mixing gearbox?
Combines two engine inputs into the input pinion gears and directs their torque to the aft transmission
What type of oil cooler does the 107 have?
Radiator type. Draws air, not blows it
What is the speed reduction in the mix box?
7.6:1
How are the mix box and aft transmission mounted in relation to each other?
Mounted together. Two separate functions but one integral unit. Lubricated by the same sump.
What is the speed reduction on the aft transmission?
9.7:1
What does the aft transmission house?
Input pinion gear and a sun and planet gear reduction
What imparts lift to the fuselage? How?
Thrust deck in aft pylon. Very shaft is splined to input pinion gear in aft transmission. Very shaft is bolted to thrust deck. Very shaft is not hard mounted to aft transmission, allowing lift to be imparted on the airframe at the thrust deck
What accessories are mounted on the aft transmission?
2 AC generators
Oil pump
Nr tach gen
Rotor over speed sensor
What is driven by the aft transmission oil pump?
Nr tach gen
Rotor over speed sensor
How is the vert shaft supported on the top end?
By a thrust bearing and slider guide.
How are the sync shafts connected?
Thomas couplings
What are Thomas couplings mounted to and what’s their purpose?
Lord mounts
To allow for bending and twisting of the airframe
What is the forward transmission speed reduction?
9.7:1
How is lift imparted on the fwd transmission?
The drive shaft to the rotor head is an integral part of the planetary gear reduction so all lift is imparted directly on the fwd transmission.
What is mounted on the fwd transmission?
2 hydraulic pumps
Transmission lubrication pump
What type of magnetic chip plugs do the fwd and aft transmissions have?
Self sealing Bayonet style
Does each transmission have its own chip detector warning light?
No. Each has its own mag plug, but they share a common master caution warning light “CHIP DETECTOR”
How do the fwd and aft transmission transmit pressure and temp?
Thermoswitch and temp bulb
Pressure transmitter and warning unit
At what oil temps is transmission oil allowed to bypass the oil cooler?
130 - 160F
At what pressure differential will the transmission oil cooler bypass should the cooler become clogged?
40 PSI
When will the XMSN OIL PRESS master caution light come on?
Below 20 PSI
Above 85 PSI
How is oil pressure indicating powered?
26 VAC 400hz
When will XMSN OIL TEMP master caution illuminate?
115C or greater
RFM states max oil temp 110C
What is the purpose of the rain shields?
Protect flight controls from inclement weather
