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A follow-on to Thomas' diagram (in answer to Swampyankee's query), there was a center joint supported by a bearing.Now we see "center bearing support for flexible splines coupling", and a whole new arena of potential disaster scenarios opens up. I hope that center bearing support is bolted to some mighty robust structure, or I see a potential wrecking ball.
Very interesting. And apparently devoid of U-joints.Shown here, from a P-39Q, is the driveline between the V-1710-85 and the propellor's gearbox. The first segment of shaft (60 inches) runs beneath the cockpit. The last segment (60 inches) runs beneath the weapon bay.
The drive shaft only weighed about 10lbs. If you put the engine in the front you increase the weight a couple hundred pounds for a new engine mount. Basically no engine mount on the P-39 since it was mounted on the wing.Suggest you take a P39. Put the engine in front of the pilot, saving the weight and complexity of the drive shaft, its supporting structure and making it less twitchy on COG issues. Move the guns to the wings with uniform 0.50.
It would weigh a lot less than the P40 with similar power equalling a better performance.
Reduction gearbox armor on the P-39 is unnecessary since no other planes had armored reduction gearboxes. Now the gearbox itself may be sturdy enough to withstand a direct hit, but I doubt it.The gearbox and reduction box at either end were armored for a reason.
The driveshaft transferred a great deal of energy and if either gearbox was damaged, then all that energy stored in the shaft under load has to go somewhere.
A bullet through the prop was not enough to stop the aircraft - a P-47 took a 20mm round through a prop and flew back to England. Matyer of fact, a P-47 flew through an Olive grove, bending back all four of the props (amongst other things) and still flew over 100 miles back to base.
So back to the core of the issue:
Is the armor at the prop's gearbox nessecary? Yes.
Is the armor at the engine's gearbox nessecary? Yes.
Reason for the armor? To prevent catastrophic failure if struck by projectiles while in combat.
Can you imagine that right underneath a full load of 37MM and .50 cal ammo?Just an example of what a driveshaft can do when it fails under load:
Reduction gearbox armor on the P-39 is unnecessary since no other planes had armored reduction gearboxes.
There were no structural issues with the driveshaft. No need for the nose gearbox armor plate, no issues with the symmetrical airfoil, and no tumbling problems. Only problem was it was too heavy to climb above 20000ft with a drop tank. Dump the wing .30s and the nose armor and even that is fixed. Move on.
Notice that the shaft breached the safety devices and ripped through the Camero's steel floorpan and steel tunnel?Can you imagine that right underneath a full load of 37MM and .50 cal ammo?
Can you imagine that right underneath a full load of 37MM and .50 cal ammo?
The drive shaft only weighed about 10lbs. If you put the engine in the front you increase the weight a couple hundred pounds for a new engine mount. Basically no engine mount on the P-39 since it was mounted on the wing.
Or your balls!
Armor plated codpiece, anyone?Testicular fortitude required.
Not sure about the gearbox's weight, but the shaft (each one) would have weighed at least 75 pounds. They weren't hollow like an automobile, but rather turned from solid stock (much like a hydraulic ram) in order to handle the torque between the engine and the prop's loading as well as being "tuned" (balanced rotationally).Also, how much did the gearbox weigh?
Not sure about the gearbox's weight, but the shaft (each one) would have weighed at least 75 pounds. They weren't hollow like an automobile, but rather turned from solid stock (much like a hydraulic ram) in order to handle the torque between the engine and the prop's loading as well as being "tuned" (balanced rotationally).
Now we need a description how the flexible splines coupling works.
I saw that original comment and figured it was supposed to read "100 pounds", which would be realistic.75lbs each? I was assured that it only weighed 10lb!
That's probably where the Skua needs help the most, where its 905 hp Perseus (55" dia, 1,025 lb) engine needs a replacement. What pre-Hercules options do we have? The Bristol Taurus is rated at 1,050 hp and at 46" wide and 1,301 lb. it could allow the Skua's engine bay to be narrowed and more streamlined, but it's 30% heavier.OTOH - engine was firmly behind the curve by 1940.
All in all, perhaps going with Fulmar or Henley as a dive bomber nets you a better solution for 1939-42?