# Tag Info

9

In Europe hybrid electric bikes are becoming quite popular - you pedal and a small battery + motor gives you an extra push. Such bikes include regenerative braking: when you brake gently the motor operates "in reverse" and charges the battery back up. Given that all the hardware is already there it is not a big additional engineering challenge. It is ...

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Freewheel Clutch or One-Way-Bearing or Sprag Clutch: More information: Freewheel Clutch Types Sprag Clutch Information Cross+Morse Freewheel Clutch Catalog

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

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What you are missing is that it is cheaper to increase the storage capacity of a flywheel by increasing its rotating speed than it is by making the flywheel bigger. This is the reason why (proposed) kinetic energy storage flywheels rotate at speeds high enough to generate stresses that are almost but not quite big enough to make the flywheel tear itself to ...

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With some low friction bearings you can spin it on the shaft and wait for it to come to a rest and mark the low point, do this a few times and you may see them gathering at the bottom. Then drill out a portion of the wheel where it is heaviest and repeat.

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Another difficulty would be the gyroscopic effect - given the speed of the flywheel, the forces would be enormous, coming down that Alpine pass, you'd probably flip over at the first hairpin bend (switchback in the USA). Could be solved with dual contra-rotating flywheels, but that just adds more complexity on an already too complex solution. The hybrid ...

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Angular momentum $$L=I\omega$$, Is the rotational momentum of a flywheel or a rotating object and is the product of I with angular velocity. It is preserved by conservation of angular momentum law. It is analogous to linear momentum. For a disk $$L=\omega*1/2MR^2,\quad generally \ L=K^2M, \quad\text{K= radius of gyration}$$ It is a vector value. Wikipedia ...

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