Ball Bearings Are Flat - Another Myth Crushed

What shape are ball bearings? They are shapedare called roller bearings (Yes, finally something
like a ball, as everyone knows, right?that makes sense!). Other bearings look just like
The funny thing about what everyone knows ismetal tubes, called plain bearings or bush bearings.
that everyone can be wrong. For instance,They look like sawed off pipe or tube (something
everybody thinks that the America's Cup is anmy metal tube bending client would be turning into
ocean-sailing race, and yet the Swiss managed toarchitecturally glamorous structural supports).
win the Cup. For those readers who areThe principle of bearings is the same principle
geographically-challenged, Switzerland is abehind the wheel: things move better by rolling
land-locked country comprised entirely ofthan by sliding. They are called "bearings" because
mountains.they bear the weight of the object, such as an
What does this have to do with ball bearings.inline skate or the head of dentist's drill, allowing
Very little, I suspect, but balls have very little tothe object to glide over them with incredible ease
do with ball bearings, either. Ball bearings lookand speed. Unlike wheels, they don't turn on an
more like hula hoops. But don't try using them foraxel; they turn on themselves.
that - you will find them inconveniently heavy andYou can see this in action with some great
painfully small.cut-away pictures of bearings.
You can view a picture of a ball bearing in theThe balls or rollers spin on themselves inside the
middle of this ball bearing supplier's page.bearing, reducing friction for the machine parts
So what are those stunted metal tube donutsattached to them. It's much neater than using a
called ball bearings for anyway? Are they used asbucket of oil, especially in dental equipment, and
a spare wheel? Do they hold in evil shop-floorsignificantly more reliable than hamsters on a
spirits? No, they help things move more efficiently.wheel.
In an early demonstration of bearing usage, threeOnce upon a time, all bearings were metal - like a
ladies pulled a locomotive (It was just ametal tube or pipe with metal balls stuck inside.
demonstration, not a career development).These days, more and more are made of
Many bearings look very similar, whether they areceramic or even plastic (like everything else in this
ball bearings, roller bearings or other bearings.world!).
What?! Other bearings?If you are still confused about why ball bearings
What is a ball bearing, anyway?are not shaped like balls, just remember that you
Ball bearings are formed with an outer ring, andrive on a parkway and park on a driveway. And
inner ring, a cage or a retainer inside, and a rollingyou can even try sailing your sea-craft through
element inside, typically a ball (which is why theythe Swiss Alps. But don't try playing a game of
are called ball bearings). Roller bearings are formedone-on one basketbearing.
using a roller instead of a ball, which is why they