R44 Main Rotor to Tail Rotor RPM Ratio
feel free to contact us ms@robinsonhelicopters.org

 

Pierre
Member Since : 2020
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R44 Main Rotor to Tail Rotor RPM Ratio

02-19-2020 03:39:54

What is the Main Rotor to Tail Rotor RPM Ratio on a R44 ?

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William
Member Since : 2017
Posts(8)
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02-21-2020 01:05:15

The Drive Line to Main Rotor ratio is 11:57 speed reducing gears.

The Drive Line to Tail Rotor ratio is 31:27 speed increasing ratio

Pierre
Member Since : 2020
Posts(2)
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02-21-2020 01:31:12

Ok thanks!!

 

Can you help me with Engine RPM to Main Rotor RPM ratio (on a R44)  ?

 

William
Member Since : 2017
Posts(8)
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02-22-2020 12:13:58

No problem.

 

Engine to Upper Sheave: four double vee belts 0.778:1 speed reducing

Upper Sheave to Drive line: sprag type overrunning clutch.

 

All this can be found in the POH for the Robinson.  If you dont have one you can go to the Robionson aircraft website for manuals on there.  They also have the maintenance manuals posted on that site also.

William
Member Since : 2017
Posts(8)
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02-22-2020 12:13:59

No problem.

 

Engine to Upper Sheave: four double vee belts 0.778:1 speed reducing

Upper Sheave to Drive line: sprag type overrunning clutch.

 

All this can be found in the POH for the Robinson.  If you dont have one you can go to the Robionson aircraft website for manuals on there.  They also have the maintenance manuals posted on that site also.

Pierre
Member Since : 2020
Posts(2)
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02-22-2020 03:02:47

Thanks again!!

 

From this, I have calculated, at 102% we have an Engine RPM of 2718, 

which in turn give us a Drive Line speed of 2115 RPM, 

and from this, a Main Rotor RPM of 408, and Tail Rotor RPM of 2428.

The Engine turns 6.66 times the speed of the MR, and 1.12 times the speed of the TR.

William
Member Since : 2017
Posts(8)
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02-22-2020 06:01:35

Awesome! Glad I could help.

 

Will