Bearings are awesome. We love them. That’s how we roll – man. (oof!) But the humble bearing may just be about to get a redesign that will not only improve their efficiency a lot but could actually make them cheaper.
The bearings in your wheels consist of a string of ball bearings in a metal ring, usually separated by a plastic collar (or retaining ring) that prevents the ball bearings from coming in to contact with each other. It’s this contact between the ball bearings that increases friction and the collar is used to keep them apart. Of course the collar itself introduces an element of friction and it’s for this reason that you have to grease your balls, so to speak.
So, if only there was a way to keep the ball bearings apart without using little bits of plastic we’d be able to do without the need for regular greasing. Well, now there is.
It turns out that all you need to keep the individual balls separated inside the casing ring is to engineer a few dimples around the surface of the bearing face that the balls run along. At first it sounds counter intuitive that instead of a smooth surface for the balls to run over you should actually have one that includes a bump. The way it works is that as a ball encounters a bump it slows down a bit and then accelerates. It’s this slight change of speed that allows a small gap to be maintained between the balls. With a carefully placed pattern of dimples it’s possible to have a bearing where none of the balls ever come into contact with each other and the results can be seen in this video.
Now theoretically at least, these improved, greaseless bearings without a ballbearing retaining collar should be very easy to make and should be as cheap as existing bearings. But we won’t hold our breath on that. But wheel bearings that roll better and need less maintenance may not be too far away.
The full story and more details can be read on the Popular Mechanics website.