Item 1010
DESIGN: UniCopter ~ Power Train - Reduction - Primary - Engine @ 12º - All Gear (total of 6 gears) (for use with Item 0999)
Drawing:
Items that must be included, but Relocated or Modified:
The mechanical fuel pump is driven from the upper shaft. Can it be moved further aft, closer to the thinner gear that is driving the governor?
The following only need a drive to it.
The Woodward governor is driven via the prop gear.
The following appear to be mounted below the gearcase;
The sensor for oil pressure.
The oil pump.
The sensor for oil temperature.
The oil filter.
Possible problems:
Can crankshaft accept axial load from pinion? Will a specific handing of the spiral reduce this axial load?
How does pinion retaining nut go on?
Crankshaft will have to have stub ending cut off.
To Do:
Get pinion to fit in by increasing the diameter of the gear and pinion plus decreasing the face width? The gear may not have to be increased all that much since the ratio should be reduced.
The pilot is a long way forward.
Notes:
Ratio 2.45:1. 912 UL / A / F is 2.27:1 with option of 2.45:1
For use on Assemble
0999Use Rotax Housing as part of mold for new housing.
Notes re Spiral Bevel Gear Set:
Arrow Gear Calculations; for diametral Pitch of 7 and 15/45 teeth. Items 0193 & 0194:
Gear has 6.438" outside diameter. The outside diameter of the axle centrifugal clutch is 6.5" diameter, there for the primary ratio can be 3:1 or anything less down to around 2.58:1 by increasing pinion diameter.
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Horsepower: |
85.4 |
hp |
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Pinion Speed: |
5000 |
rpm |
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Pinion Working Torque: |
1076.5 |
in-lb |
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Estimated Rated Pinion Torque: |
2152.9 |
in-lb |
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Catalog Rated Pinion Torque: |
1604 |
in-lb |
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Catalog Pinion Pitch Diameter: |
2.145 |
in |
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Pitch Line Velocity: |
2810 |
ft/min |
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Dynamic Factor: |
0.772 |
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Allowable Pinion Torque: |
1238 |
in-lb |
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Service Factor: |
1.15 |
:1 |
Notes:
See
FORM: Gear - Bevel for calculations of axial load etc. It appears that the force drawing the pinion forward is 617 pounds. Is this excessive and/or can a thrust washer be placed at the end of the crankshaft.All of this may cause a problem with the engine.
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Last Revised: December 28, 2001