Epicyclic gearing: 3 free axes

[Cri85]

Homework Statement

The teacher said it is possible to use an epicyclic gearing with no axis fixed but nobody use the gearing like that. I watched this video:



at time 42s it's possible to watch it. I have 2 questions:

1) Is it possible to used the epicycloidal train with no axis fixed ?

2) If yes, what is the ratio of reduction ? is it dependant of the torque ?

Maybe if you have a link ?

Homework Equations

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The Attempt at a Solution

I'm looking for this case, but each time the epicyclic gearing is used with one fixed axis.

 

[mfb]

1) Is it possible to used the epicycloidal train with no axis fixed ?

I don't see an argument against it.

2) If yes, what is the ratio of reduction ? is it dependant of the torque ?

You have to consider all three rotations at the same time. Things like a ratio of reduction that consider only two do not make sense any more. That's probably the reason they are not used in that mode.

 

[Cri85]

Things like a ratio of reduction that consider only two do not make sense any more.

I can set the input to the sun gear and the output to the ring gear (planets are free to turn like they want) ? Why there is no a ratio ?

In this case, it's possible to reduce a rotational velocity without give a torque on the support ?

 

[mfb]

(planets are free to turn like they want) ?

Then your output will not get any torque (neglecting friction). The free axis will rotate with the right speed to give zero output power.

 

[HalfLostAndSearching]

I can provide a response to the content provided.

1) Yes, it is possible to use an epicyclic gearing with no axis fixed. This is known as a "free axis" configuration. In this configuration, the gears are able to rotate freely around their respective axes, without any fixed point. However, as the teacher mentioned, this configuration is not commonly used in practical applications.

2) The ratio of reduction in a free axis epicyclic gearing is dependent on the number of teeth on each gear. This ratio can be calculated using the formula:

Ratio of reduction = (Number of teeth on sun gear + Number of teeth on planet gear) / Number of teeth on planet gear

This ratio is not directly dependent on the torque, but it can indirectly affect the torque due to the change in gear ratio.

I am unable to provide a specific link for this configuration, as it is not commonly used and may not have been extensively studied or documented. However, you may be able to find more information by searching for "free axis epicyclic gearing" or "free axis planetary gearing".