6
$\begingroup$

I have the following to wheels that rotate on the same axis:

enter image description here

Assuming that they are stuck together, if I rotate the green one the red one rotates at the same speed and when I stop the green one the red one stops.

I'm looking for the name of the mechanism that makes it so that when I stop rotating the green wheel and I hold it in place, the red one keeps turning.

PS: I'm building a flywheel (represented here by the red wheel) and the green wheel here is connected with a belt to a crank. I want to make it so that the flywheel keeps turning even when the crank is fully stopped.

$\endgroup$
  • 1
    $\begingroup$ The answers are correct; just thought I'd point out that you can find mechanisms like this in the rear hub of a bicycle and in the connection between a starter motor and the engine of an automobile. $\endgroup$ – Carl Witthoft Mar 3 '16 at 15:37
  • 1
    $\begingroup$ To add another fun fact along with Carl's, it's this freewheel clutch that gives a bike it's characteristic clicking while the rider coasts. $\endgroup$ – William S. Godfrey- S.E. Mar 4 '16 at 1:07
5
$\begingroup$

It's called a "freewheel" or "overrunning clutch".

$\endgroup$
5
$\begingroup$

Freewheel Clutch or
One-Way-Bearing or
Sprag Clutch:

enter image description here


More information:
Freewheel Clutch Types
Sprag Clutch Information
Cross+Morse Freewheel Clutch Catalog

$\endgroup$
0
$\begingroup$

Another solution which is based on spur gears+springs rather than a clutch

Another solution which is based on spur gears+differentials rather than a clutch

Found using the keyword "rotation rectifier" (since it's the mechanical equivalent of an electrical rectifier in which alternating current is converted to direct current).

$\endgroup$
  • $\begingroup$ Both of those mechanisms use ratchets to prevent reverse motion of a shaft. None of this is relevant to the original question. $\endgroup$ – Dave Tweed Mar 8 '16 at 16:11
  • $\begingroup$ I was looking for that term in english, thanks. I beg to differ, as the OP has asked for a way to let the driven part rotate freely when the drive is removed, which is clearly demonstrated at least in the second solution at youtu.be/-p8zrvU-cYE?t=2m3s. Though I admit wear and load friction on the drive is not ideal, this is still a solution. $\endgroup$ – Mister Mystère Mar 8 '16 at 16:58

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.