glued belt to inside of rim using multiple similar pulleys hemicyclic?

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whereswally606   100 kW

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glued belt to inside of rim using multiple similar pulleys hemicyclic?

Post by whereswally606 » Aug 17 2018 9:44am

so I had an idea come to me about using small high speed rc drives and the rim of the wheel but to increase/share the torque out over many teeth in a manner with half resembles the epicycle gears in a geared hub.

Time for a picture.
idea for a rim drive.png
I don't know if this would work or whether or not all circles of the gears spin at the same speed. I keep thinking they must spin the same speed but then I waver and think they wouldn't.

I think the main issue would be whether the gears would actually mesh right and that would be a factors type math problem. The augmenting gears are just to share out the torque and give more strength holding the outer most pulleys into the belt.

I hope its a clear enough diagram one day I might get round to building one.

I thought I made up the term hemicycle but in fact it is the exact description of the relative locations of the pulleys.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
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amberwolf   100 GW

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Re: glued belt to inside of rim using multiple similar pulleys hemicyclic?

Post by amberwolf » Aug 17 2018 9:45pm

If this is meant to drive the inner circumference of a rim, then I don't see why it wouldn't work, if you ahve a wide enough rim for these to clear the spoke nipples.

However, if you don't ride on nice clean streets, I can imagine the teeth getting ground up by the dust and dirt, and possibly jammed by other debris.

whereswally606   100 kW

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Re: glued belt to inside of rim using multiple similar pulleys hemicyclic?

Post by whereswally606 » Aug 23 2018 12:17pm

I was looking on vicious1.com home of the mpcnc and a guy had used two belts interlocking to reduce the belt stretch on his x and y axis.
I took his idea and adapted it to work on a bikes inner rim.
dual belt rim drive with rim to scale 26inch.png
this is to scale with a 26inch wheel
dual belt rim drive.png
dual belt rim drive.png (78.14 KiB) Viewed 468 times
this is a close up to show how the drive would work. the big cylinder would be the driven pully the smaller ones are just bearing to guide the back of the belt. Again no idea whether this could work but this could be even cheaper so it might be worth a go.
Distributing "Lebowski" FOC Controller PCB (Through hole) since 2016
Moped: Emax 110s 2009

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