New accessory drive system developed - Fuel Economy, Hypermiling, EcoModding News and Forum

ai_vin · 03-17-2009, 01:03 PM

Quote:

Continuously Variable Accessory Drives (CVADs)

A continuously variable accessory drive (CVAD) is a device that helps the front-end accessories on a car or truck engine (alternator, air conditioner, water pump, etc.) run more efficiently. These belt-driven accessories have always been connected directly to the engine, so their speeds are tied to engine RPM. A CVAD sits between the engine and these accessories, allowing their speed to vary according to performance needs rather than engine RPM.

hummingbird · 03-17-2009, 02:27 PM

Great product! Simple idea, brilliant execution.

The million $ question is - Will the auto giants pay any heed? Experience has been they won't unless it is a question of survival or demise. Being an improvement over current status (not central to operation of the vehicle), this accessory drive will not be mandatory in cars, and the product really has no future unless mandated. (will survive in a niche area, but will never hit mainstream...)

NiHaoMike · 03-17-2009, 04:11 PM

Great for retrofitting existing cars, but in new cars, it is made obsolete by a shaft drive generator and electric power steering, electric power brakes, and electric water pumps. (The latest Prius doesn't have any belts.)

ConnClark · 03-18-2009, 05:03 PM

They say that this mechanism can be applied for a transmission. I wonder how it deals with high torque?

some_other_dave · 03-18-2009, 11:16 PM

I also wonder what the friction losses through it are? I may not have looked carefully enough, but I didn't see that mentioned in the website. If they're significantly less than a belt-and-pulley system, it could be a really big win! Complex and expensive, though. I wonder what the cost would be for a retrofit system, and how long it would take to make that back with fuel savings?

Hmm....

-soD

Frank Lee · 03-19-2009, 12:27 AM

The belt and pulley are still there so any savings would have to come from reduced accessory speeds- and they would have to be more than enough to compensate for the new transmission losses.

cfg83 · 03-19-2009, 05:14 AM

Hello -

If you've got the bandwidth then I think the video-demos are worth watching :

NuVinci Technology (Video) Demonstration(s)

I like the claimed scalability, from bicycles to cars to wind power. I'm a retrofit fan, so scalability is a must from my POV. If I were them I would market to the performance crowd first to get the sales going. I am guessing that performance enthusiasts would wring out the bugs too.

CarloSW2

MetroMPG · 03-19-2009, 03:25 PM

(ai_vin - hope you don't mind I posted a quote about their device in your original post.)

That's interesting - I've known about the NuVinci system for a while - originally saw it touted as an auto transmission for bicycles. Definitely seems like an invention looking for a market, and maybe they're on to something here.

ai_vin · 03-19-2009, 06:07 PM

Quote:

hope you don't mind....

I don't mind at all.

Ryland · 03-19-2009, 06:35 PM

if you go to your local bike shop they can most likely order the bike hub for you, so at least in the bicycle world it is a real product and it's not suposed to have much wear because of the weird working fluid that they use that only Valvoline makes.
I like the idea of direct drive, or a cog belt.