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Gizmag tells us about how a Japanese company, Coo Space, has developed an innovation in ball bearings that will allow the balls to automagically space themselves out. That will lead to vastly reduced friction which, in turn, will lead to the elimination of the necessity to grease the bearing to reduce the friction. This is potentially a huge development across all forms of industry.
The Autonomous Decentralised Bearing (ADB) puts a small indentation, or groove, into the outer bearing race. As the balls slide over this tiny groove, they slow down ever so slightly, and then speed back up. This does nothing to affect the bearing's regular performance, but if two balls are touching each other as they cross over the groove, the first ball's deceleration puts a tiny brake on the second ball, which separates the two as they go around the races.
It's an incredibly simple and tiny change, but it does a remarkable job.
...
Without the need for a cage, you can run these bearings un-lubricated, and that's where the real performance benefits come in. Coo Space claims the ADB experiences as little as 10 percent of the friction of a regular ball bearing
Here is a YouTube video of the bearings spacing themselves out within the races.
[Editor's Comment: Original Submission]
(Score: 4, Informative) by KilroySmith on Wednesday May 27 2015, @06:44AM
When you load the bearing, the normal force between the bearing and race becomes significantly higher than the normal force between two bearings. My intuition doesn't have a lot to say about whether two surfaces lightly rubbing against each other in opposing directions have more or less friction than two equivalent surfaces rolling past each other while loaded.
But, my experience with lubricated and unlubricated bearings seems to indicate that the roughness and noise of an unlubricated bearing "seems" to be more related to the rolling of the bearing in the race, than to the scraping of two balls against each other.
If we imagine a caged bearing (where the ball bearings are prevented from touching each other by some type of framework or cage), the friction that this summary claims is 90% of the friction of a bearing should be eliminated, although there will be some friction against the cage - proper choice of cage material should minimize that friction. And yet, in various applications, I've seen both free and caged bearing styles with no significant difference in felt friction - maybe I'm just not sensitive enough.
So, reduced friction in an unlubricated bearing? Perhaps, though the new groove will create some of it's own. I still don't see a 90% reduction. 20% I'd buy.
(Score: 2) by c0lo on Wednesday May 27 2015, @07:03AM
Good point. Thanks.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 3, Interesting) by Immerman on Wednesday May 27 2015, @04:43PM
Consider that rolling "friction" is a misnomer, it's actually rolling *resistance*, and originates primarily from a variety of deformation effects which can be minimized by using sufficiently hard materials (and/or large contact surfaces). As such, so long as the loading is insufficient to cause notable deformations in the bearings or races, it can usually be ignored. And it won't be affected by lubrication.
(Score: 2) by el_oscuro on Wednesday May 27 2015, @10:53PM
We have those caged bearings on skateboards for decades. My first board was a banana board with Cadillac wheels and loose ball bearings. A few years later, about 1975, they came out with "precision" bearings which were similar but caged. You would not believe the difference in rolling resistance.
I wouldn't mind picking up a set of greasless bearings for my Landyachtz downhill racer. Hook it up with some Monster Hawgs and Bear trucks. Schweet!!!!
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