New Drive Design - Ceramicspeed Driven 1

[SuperSalad]

I didn't see anything in the search results about this.

I saw this a few weeks back. I think it is extremely interesting and could produce some new developments. They don't appear to be rushing anything and are trying to address the inherent issues that could obviously make this a problem. If they can work out the quirks and kinks, this could be a very cool development.

Website - Link

Video - Link

Video - Link



Andrew H.

http://www.mototribology.com

 

[ctopher]

I think it's a great start. You have to build it first to test the idea.
It may (or may not) turn into something cool in the future.
I'm not going to say it will fail. Nobody knows that. Some great inventions were destine to fail by others.

Chris, CSWP
SolidWorks '17
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[Brian Malone]

Windward, agree completely with you on the issue of gunk and debris packing into the drive wheel cog disk/'cassette'. This drive will have to be shielded/enclosed to have even a slight chance for successful operation under real-world conditions. Adding an enclosure adds weight.

Ctopher - yes, building a test assembly is a start. I will be watching to see how the team solves the technical hurdle of making this system shift reliably under load and at speed. The challenge is daunting. Especially, if no clutching or synchronizers are implemented. The drive pinion will have to move only at the right time to allow its rotating drive bearing elements to leave engagement from a given location on one cog wheel to re-engage to a correct drive pocket on another cog wheel without mechanical collision. This is going to be a dance of matching the angular speeds of two systems that must momentarily become disconnected during a shift event. By definition, the cog wheels' pitch has to be at minimum the width of the pinion drive bearing face width plus some clearance gap on either side otherwise the positioning of drive pinion would have to be absolutely perfect to prevent partially engaging adjacent cog wheels. The cog wheels each are fixed number of "teeth" and the drive pinion has a fixed number of drive "bearings" so the shift points will almost certainly be only at predetermined shift channels/points. Making the transition from one cog wheel to the next in a near instantaneous manner during a shift will be tough. Unlike a chain and sprocket transmission where the chain transitions from one sprocket to next with power slightly shared between the sprockets during a shift, the Ceramicspeed assembly must make a complete jump from cog wheel to cog wheel. With power applied to the driveshaft, at the moment of disconnect from one cog wheel the resistive force on the drive pinion will go to zero, the drive shaft will spin up (the rider is still hammering on the pedals), only to slam into resistance when the driven pinion's next drive bearing has rotated around and hopefully is timed properly to meet with a drive pocket in the target cog wheel. I can feel the crazy leg spin that will happen as I type this! If the shift engagement does occur, this will be a slamming engagement at the pinion drive bearing and cog wheel faces. If the shift misses, the rider will have to stop pedaling to let the drive engage, then try to resume cadence and power application. Wow! Trying to shift through multiple cogs will be really ugly. I am a gearhead and I am rooting for their success - shifting this system is a major hurdle. Making the idea demo prototype has been the easier part. Often with a design the toughest 10% takes 90% of the effort!

 

[Brian Malone]

Just found this website Link

gives some more views of the Ceramicspeed DrivEn design and prototypes and a little better view of some of the components. One of the 3D printed cog wheels shows some of the proposed shift channels - Ceramicspeed could fully optimize these to perform as the synchro for the drive pinion.

As quoted from the Cycling Tips story: “We talked a lot about this automated system and the brain,” said Alex Rosenberry, the engineering student who managed the project on the University of Colorado side of things (and who now works for CeramicSpeed as a contractor). “The system would have to be pretty intelligent to know how fast the system is moving. It’d have to be pretty smart to know how fast it’s moving, which tooth track to select to make the shift happen. Would you have to back off to shift under high load? We’re not sure yet, but there’s definitely potential to make it work.”

Crazy! Gears, bearings and drive shafts! All that remains is making it shift smoothly, reliably and able to sustain torque loads without jumping teeth.

 

[ctopher]

Every time I look at that big rear plate, I think about all the times riding seeing all the stuff on the road. Imagine a piece of plastic bag flying up and getting trapped in there! It's looks too easy to get trapped, and a b*tch to remove!

Chris, CSWP
SolidWorks '17
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[SuperSalad]

Ctopher, I'm confused why this seems to be the hangup a lot of people have (not just your post, I've seen it elsewhere too when I was first looking at this)

I see no reason why there would not be a cover over this to protect it from debris. I just assumed that would be the case. Plenty of lightweight material to use for what I would think would be a simple protective cover.

Andrew H.

http://www.mototribology.com

 

[ctopher]

It's the first thing I would do, design a cover for it.
If you go cycling a lot, you know debris 'will' eventually get hung up in the components.

Chris, CSWP
SolidWorks '17
ctophers home
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[chicopee]

Sand, dirt and twigs will be a problem unless they can enclose the gearing system.