Two independent driven inputs one output

[joshb93]

Hello everyone,

I've been trying to figure out how i can have two different inputs that are switchable from one to another that drive a single output. However i don't want the inputs to drive each other, and also want the mechanism to be compact in size and fairly lightweight. So how can i do this?

INFO
I have one engine that is a high speed the other source is a hand/foot powered one. I have all ready researched about different types of clutch but this will be to bulky for the application, unless a centrifugal clutch was used but that still does not solve the problem of the handles/pedals rotating when the engine is working. I have also looked at a free wheel mechanism like you find on a push bike but still can't figure out how to get this to work how i want it to. Lastly i have looked at epicyclic/planetary gears but just can't understand how it work with two inputs leaving handles/pedals in a free motion.

To say the least i have slightly confused myself, perhaps I've been over thinking the problem and there is a simple answer, but its really bugging me now so i appreciate any help you can offer.

Thanks Josh,

 

[Averagesupernova]

https://www.physicsforums.com/showthread.php?t=744489

 

[joshb93]

Hi Averages, thanks for the reply that isn't exactly what i was looking for, its my fault i hadn't worded the question quite right, in simple terms i have two inputs i want these to stay separate and not power each other and then i want to be able to easily switch from one input to the other (only have one input on at a time).

 

[FactChecker]

You could have each input "ratchet" and coast when the other input is providing more power. Then only the greater power input would actually drive the system at any time.

 

[Dnomyar]

Or could you drive through hydraulics - and each input would raise the hydraulic total power ?

 

[Baluncore]

One possibility would be to have the two splined input drive shafts end to end, with a splined sleeve output that can slide along the shaft onto one or the other to select drive to the output.

Similarly, sliding an output gear between two input gear wheels would select one input only.