What do you call a mechanism where rotation is transfered in one direction only?

Question

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

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.

score 5 · Accepted Answer · answered Mar 03 '16 at 03:27

5

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

answered Mar 03 '16 at 03:27

Dave Tweed

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score 5 · Answer 2 · answered Mar 03 '16 at 04:42

5

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

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

answered Mar 03 '16 at 04:42

ericnutsch

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score 0 · Answer 3 · answered Mar 08 '16 at 12:07

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).

What do you call a mechanism where rotation is transfered in one direction only?

3 Answers3