Epicyclic for torque balancing? 1

[BillClark]

I am having a hard time getting my head around this concept and if it would even work and was hoping a sharper mind could help. I have seen it work by driving the sun but can it work by driving the ring. In this example (see attachment) the drive is in yellow. A propeller is attached to the Carrier and another propeller having reverse pitch is attached to the sun. The torque from the Carrier prop turns the planets driving the Sun prop in the opposite direction. We will assume both props require the same torque to turn at the same speed opposite of one another. Ideally if one prop did consume more than the other the mechanism would compensate by balancing the loads by speeding up the other. This mechanism would use friction elements as opposed to gears so we need not be concerned about the correct number of teeth. The question is 1) will it work? and 2)with a ring diameter of 100, what would be the diameter of the sun and planets and what would their individual reductions be?

 

[gruntguru]

Yes it will work but the two output torques will never be the same magnitude (dark blue - green = light blue in your diagram) and therefore the prop torques do not cancel. Also the power to each prop will be unequal (by an even greater ratio than the torques).

je suis charlie

 

[BillClark]

Thanks you for your response gg. It appears that driving the sun and attaching the props to the carrier and ring work as there are some examples of this out there. If I went that route is there a relationship between the ring and carrier I should look for to produce an equilibrium?

Edit- I was able to find a few photos (use link to my dropbox)of the example I was referencing. I would like to create a scaled down version of this unit. the gearing is s=16, p=32, and ring with 80

https://www.dropbox.com/sh/gtbu5m8sxbqxev1/AACEzHc-3h8GEOj7gl-BXANNa?dl=0

 

[gruntguru]

Carrier locked.-> Sun/Ring = 5/1 so Ring torque = Sun torque x 5
Ring locked.-> Sun/Carrier = -4/1 so Carrier torque = Sun torque x -4

Regardless of the ratios you choose you always get Carrier torque = -(Ring torque - 1) so the torques can never be equal. You could put a larger/coarser prop on the ring if you wanted to equalize the power split.

je suis charlie

 

[tbuelna]

As noted, due to difference in friction losses between the single input and each of the two outputs, and/or the difference in load produced at each of the two fixed pitch props, it will be hard to get an even torque split.

 

[gruntguru]

"As noted, due to difference in friction losses between the single input and each of the two outputs, and/or the difference in load produced at each of the two fixed pitch props, it will be hard to get an even torque split."
More than "hard". It is actually impossible to get an equal torque split since the output torques will always be in the ratio dictated by the gearbox ie 5:-4 in the example given and never 1:-1 for a simple planetary box.

je suis charlie

 

[BillClark]

I have been working other differentials (and realizing they dont work). I am wondering what if we were no longer bound to having all the elements in one plane? What if we canted the planets? Could we achieve torque balancing of the outputs? See the dropbox link below for cutaway, side view, examples of what I am thinking and also some fails

https://www.dropbox.com/sh/hoxc4cxl9x0y3da/AACTjqromu_34SmowP-2DJt8a?dl=0

 

[spigor]

How about using this setup:

https://upload.wikimedia.org/wikipe...ntial_(Manual_of_Driving_and_Maintenance).jpg

?
You drive the housing.