Frictionless automotive ball bearings

[intalect187]

About 8 years back i remember my father telling me about a guy who had invented a set of frictionless ball bearings using magnets, he installed the ball bearings on an old buick or somthing of the sort that was a heavy boat of a vehicle. i remember my father telling me that the guy had pushed the car a little bit and then let it coast and the car coasted a 1/4 mile before it came to a complete stop.

i didnt really think about it then because i wasnt old enough to drive yet. Well... i am now 23 years old and have been into drag racing and automotive performance for a long time now.
I recently started thinking about what my father told me and realized that with a frictionless ball bearing that could enable a vehicle to be moved with such little effort one could build quite the race car with only a fraction of the horsepower.
i also started thinking about the bennefits somthing like this could reap when fuel consumption and longevity(sp?) of the power train parts are brought into play on just an everyday commuter car.

I don't remember much about what my father told me but i do remember him mentioning somthing about the acctual ball bearing floating and not even touching any other metal part making it a true frictionless setup.

i was wondering if anyone might have any information on this subject because i have searched the internet and found nothing about it.
i was also wondering if anyone might be able to fabricate somthing of this sort as i am extremely interested in getting my hands on somthing like this for my next project car.

if you or anyone you know can provide any more information about this please Email me ASAP @ Intalect187@msn.com.

thank you
joel Brown.

 

[russ_watters]

Well, actually, at high speed, the large majority of the resistance to a car's motion is wind resistance, not rolling friction or bearing friction, so it wouldn't make all that much difference.

Anyway, I'm not sure I could see how a magnetic bearing would work - since there are variable forces involved, I don't see how it could actually hold a shaft in place.

 

[AlephZero]

Anyway, I'm not sure I could see how a magnetic bearing would work - since there are variable forces involved, I don't see how it could actually hold a shaft in place.

Magnetic bearings do exist, but they use electromagnets and a control system, so they wouldn't be a "drop in" replacement for a car wheel bearing. They are not too good at handling large "random varying" loads like you would get in a car suspension either.

As well as no friction, another advantage in some applications is no lubrication requirements.

Google "active magnetic bearing" or AMB.

 

[Danger]

I suspect that it might be theoretically possible to build magnetic bearings with a strong enough field for this application, but you'd probably need superconducting magnets and the power source would be enormous. The several tonnes of additional equipment and fuel to power it would far overwhelm the miniscule efficiency increase of the axles. As Russ mentioned, you'd be better off streamlining where possible and make sure to keep your normal bearings properly lubricated.

 

[Astronuc]

AFAIK - there are no - frictionless ball bearings using magnets.

It's either ball/roller bearings or magnetic bearings, although mechanical (ball or roller) bearings serve as backup for when the shaft is still or at low speed.

http://www.skf.com/portal/skf_rev/home
http://www.skf.com/files/081420.pdf

http://www.waukbearing.com/operation.html

http://www.airex.com/products/magnetic.htm [Broken]

http://www.fz-juelich.de/zat/magneten [Broken]

And as Russ and Danger mentioned, a streamlined body to minimize air-resistance is more effective.

 

[FredGarvin]

The area of magnetic bearings is on going. We are always looking at that stuff for our engine applications. The thoght of having a highspeed, low heat generating bearing that does not require an oil system is a home run if we could get one. So the usage in our case is indeed justified by weight savings and increased performance.

The major problem now is that the system is complicated because of the varying loads imposed during operations and the size of the set ups.

I have not heard of one for a car, but I can see how that would probably be the easiest scenario to implement.

 

[Danger]

I have not heard of one for a car, but I can see how that would probably be the easiest scenario to implement.

Fred;
Despite your being my hero, I have to disagree on this point. Any application that is either stationary or not in contact with the ground would be simpler. The multple-axis random and violent shock loads inflicted upon an automotive suspension system are far different from those encountered in something like a jet engine or an industrial machine environment. Shock absorber technology alone is evolving by the minute.

 

[FredGarvin]

I meant in terms of a variational loading. Something like a car's main wheel bearings is a lot more simple that say a crank shaft bearing or a transmission bearing where the forces change drastically at very high frequencies. It's just a guess on my part though. I have never dealt with a mag bearing before.

 

[Danger]

Okay, I see what you mean. I hadn't considered those applications as being the alternative. It was an assumption, based upon your career, that you meant as opposed to a turbine or similar load. A crankshaft would definately be subject to more complex shock loads and harmonics. I do still think, however, that the portability factor alone would rule it out for automotive use.

 

[AlephZero]

In the jet engine field, remember the shock loads for component failure conditions and other "unexpected" events (engine surge, heavy landings, etc) can be very large. For example 100,000 cycles of 10,000 lbf load, while you get from mid ocean to the nearest airfield. If you need a backup system that can take over the whole task when required, that defeats the object.

Fred's company isn't the only jet engine maker looking seriously at them though. The design advantages of a no-lubrication bearing system are worth the challenge.

Since there is an active control system, you can design the controller to handle to the loads spectrum you expect to see. Crankshaft loads are complex but fairly easy to predict, I would have thought - linking the engine management system to the AMB controller would be a no brainer to help with that.

I expect the main "problem" with the auto application (at least for mainstream vehicles) is there is no economic reason for it, when roller bearings do the job pretty well already. You could get far more energy savings by reducing aerodynamic drag and vehicle mass than by messing with bearing design.

 

[Danger]

That's a lot more complex than I realized. I still can't see how enough field strength can be generated for something on that scale, though. Wouldn't it need to be at least in the range of one of those junkyard cranes, at less than 5% of the size?

 

[P.Ramesh]

similar to those frictionless bearing, FOIL type bearing are into use where rpm of 3,000,000 to 3,500,000 involed. like turbo-charger of an automobile.

http://en.wikipedia.org/wiki/Foil_bearing

I have not come across magnetic type in practise.

 

[AlephZero]

...where rpm of 3,000,000 to 3,500,000 involed. like turbo-charger of an automobile.

Pardon?

A while back I worked with BMW's expert on turbocharger dynamics for a couple of years...

 

[Danger]

Pardon?

Man, I didn't notice those extra zeroes in there.
I thought that he said 3,000 to 3,500 and thought that is sounded pretty low...

 

[AlephZero]

I thought that he said 3,000 to 3,500 and thought that is sounded pretty low...

100,000 to 200,000 RPM is believeable. 3,000,000 seems a bit optimistic though.

 

[FredGarvin]

100 krpm is the range. There is no way something has a rotational speed that high. We've had small turbines in the 200 krpm and that was friggin' hauling!

The only thing I can think of is maybe the post was referring to the bearing DN numbers for a turbo...Probably not.

 

[P.Ramesh]

Pardon?

A while back I worked with BMW's expert on turbocharger dynamics for a couple of years...

yes. its decimal problem. its 10 times lesser than what i typed. Ref wikipedia page for more info.