What are the advantages / disadvantages of a ceramic bearing.

Example - http://www.vxb.com/page/bearings/PRO...arings/Kit7183

Do they run faster without overheating or run cooler? Lubricant
requirements less critical? Longer life?

Are they more prone to damage when shocked by vibrations or trauma from
impact, etc?

Did a quick Google search and turned up some info, but would love some "in
the field" information if available.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R

Joe AutoDrill wrote:
What are the advantages / disadvantages of a ceramic bearing.

Example - http://www.vxb.com/page/bearings/PRO...arings/Kit7183

Do they run faster without overheating or run cooler? Lubricant
requirements less critical? Longer life?

Various motorsports use 'em in a variety of applications. The balls
have less mass and better dimensional stability, so they behave better
as speed and heat increase. They also have slightly lower MOI. We've
used them in wheel bearing, which yields slightly more 'wheel'
horsepower (less driveline loss) Other people use them in crank and
counterbalancer applications etc.


Are they more prone to damage when shocked by vibrations or trauma from
impact, etc?

Yes! :-) But not so bad that they require a lot of extra care, just
some sensible precautions.


Did a quick Google search and turned up some info, but would love some "in
the field" information if available.


Hope this helped.

Pete


--
Pete Snell
Department of Physics
Royal Military College

---------------------------------------------------------------------
Imagination is more important than knowledge.
Albert Einstein (1879-1955)

On Wed, 10 Oct 2007 19:32:55 GMT, Joe AutoDrill wrote:

What are the advantages / disadvantages of a ceramic bearing.

Example - http://www.vxb.com/page/bearings/PRO...arings/Kit7183

Do they run faster without overheating or run cooler? Lubricant
requirements less critical? Longer life?

Are they more prone to damage when shocked by vibrations or trauma from
impact, etc?

Did a quick Google search and turned up some info, but would love some "in
the field" information if available.


If you are selling them to cyclists you can charge a LOT more money based
on the hype of drag reduction - which is true, but so tiny it is not worth
bothering about.

"Joe AutoDrill" wrote in message
news:HN9Pi.9168$C2.7251@trnddc02...
What are the advantages / disadvantages of a ceramic bearing.

Example -
http://www.vxb.com/page/bearings/PRO...arings/Kit7183

Do they run faster without overheating or run cooler? Lubricant
requirements less critical? Longer life?

Their main use has been in high-speed bearings, where the balls' lower
density (lighter weight) allows much higher rpms without overload from
centrifugal force.

When one of my former clients (Roku-Roku) moved up from 20,000 rpm spindles
to 30,000 rpm spindles, they needed hybrid ceramic bearings to handle the
speed.


Are they more prone to damage when shocked by vibrations or trauma from
impact, etc?

'Don't know.


Did a quick Google search and turned up some info, but would love some "in
the field" information if available.

Roku-Roku had specific data on life of steel bearings, hybrid ceramics
(ceramic balls, steel races) and pure ceramics, but I don't think they made
it public. You only need the pure ceramics when you were working at the
hairy edge. They cost the most. Fischer uses them, or they did, in their
high-end, high-speed spindles.

You'll find them used on very high speed spindles from several parts of the
world. The Germans like them a lot.

--
Ed Huntress

On Wed, 10 Oct 2007 19:32:55 +0000, Joe AutoDrill wrote:

What are the advantages / disadvantages of a ceramic bearing.

Example - http://www.vxb.com/page/bearings/PRO...arings/Kit7183

Do they run faster without overheating or run cooler? Lubricant
requirements less critical? Longer life?

Are they more prone to damage when shocked by vibrations or trauma from
impact, etc?

Did a quick Google search and turned up some info, but would love some "in
the field" information if available.

All the preceding, plus they're insulating, which is handy in some
electromechanical applications.

--
Tim Wescott
Control systems and communications consulting
http://www.wescottdesign.com

Need to learn how to apply control theory in your embedded system?
"Applied Control Theory for Embedded Systems" by Tim Wescott
Elsevier/Newnes, http://www.wescottdesign.com/actfes/actfes.html

"Joe AutoDrill" wrote in message
news:HN9Pi.9168$C2.7251@trnddc02...
What are the advantages / disadvantages of a ceramic bearing.

snip

They are impervious to an EMP!

On Wed, 10 Oct 2007 20:10:16 -0500, Tim Wescott
wrote:

On Wed, 10 Oct 2007 19:32:55 +0000, Joe AutoDrill wrote:

What are the advantages / disadvantages of a ceramic bearing.

Example - http://www.vxb.com/page/bearings/PRO...arings/Kit7183

Do they run faster without overheating or run cooler? Lubricant
requirements less critical? Longer life?

Are they more prone to damage when shocked by vibrations or trauma from
impact, etc?

Did a quick Google search and turned up some info, but would love some "in
the field" information if available.

All the preceding, plus they're insulating, which is handy in some
electromechanical applications.

Or bad in some applications, you may need some type of brush setup to
ground the rotating part or some serious static charge can build up.

Thank You,
Randy

Remove 333 from email address to reply.

Joe AutoDrill wrote:

What are the advantages / disadvantages of a ceramic bearing.

For your boring heads? Fuggedit. Too expensive, you don't have the rpm. You
should lubricate your steel BBs with oil before switching to ceramics.


Nick
--
The lowcost-DRO:
http://www.yadro.de

What are the advantages / disadvantages of a ceramic bearing.

For your boring heads? Fuggedit. Too expensive, you don't have the rpm.
You
should lubricate your steel BBs with oil before switching to ceramics.

We've got a few folks wanting to run heads above our 4-4500 RPM self imposed
limits... Mostly on CNC. Thus the question. I figured that if the
ceramics can run at a higher RPM rate with my same or similar synth. grease,
might be an option.

We had one guy want to tap a pipe fitting in the top of the head and vent
holes in the bottom to pump coolant through... Didn't think that was such a
bad idea IF the collant was oil... But he wanted to use water based stuff.


The housing we manufacture is made in two levels and "clam shell" assembled
and has only the very basic of seals on the shafts themselves to keep grease
in and dirt and chips out so filling them with oil doesn't work for the most
part unless it is pumped in... Or so goes my thinking.

Bottom line - better bearings might give me a few more RPM I figured
although we've NEVER had an over RPM issue that I'm aware of so maybe our
numbers are artificially low for "free insurance" as I call it.

Most heads og on drill press machines where you can't even get 4000+ RPM.

Regards,
Joe Agro, Jr.
(800) 871-5022
01.908.542.0244
Automatic / Pneumatic Drills: http://www.AutoDrill.com
Multiple Spindle Drills: http://www.Multi-Drill.com

V8013-R

Joe AutoDrill wrote:

We've got a few folks wanting to run heads above our 4-4500 RPM self
imposed limits... Â*

That depends on the diameter. :-)


The housing we manufacture is made in two levels and "clam shell"
assembled and has only the very basic of seals ...

I remember that, so my note about the oil.


Bottom line - better bearings might give me a few more RPM I figured
although we've NEVER had an over RPM issue that I'm aware of so maybe our
numbers are artificially low for "free insurance" as I call it.

When you install precision spindle bearings, rpm get higher (along with the
price). But still, the first thing to do *would* be oil mist. I doubt that
ceramic bearings will like a slap of grease. :-)

Also, the rpm given are for a certain load. You can do some math with
reduced live, increased rpm, reduced load, better cooling, etc. Try to get
a book from a good bearing manufacturer (SKF, FAG, Timken, ...) and have a
look at their dimensioning section. I bet you can save a lot of money. And
spend an afternoon with the slide rule ...

And stay away from Chinese bearings!


Nick
--
The lowcost-DRO:
http://www.yadro.de

On Wed, 10 Oct 2007 20:01:04 -0500, "Robert Swinney"
wrote:

Naw! But those used in diesel engines should be.

Bob Swinney
"Tom Gardner" wrote in message
...

"Joe AutoDrill" wrote in message
news:HN9Pi.9168$C2.7251@trnddc02...
What are the advantages / disadvantages of a ceramic bearing.

snip

They are impervious to an EMP!



Diesel engine with a mechanical fuel rack and no klever electronic computing
engines...


Mark Rand
RTFM

looking at that picture i cant imagine how those things are made.
since most ceramics shrink greatly when fired...

On Thu, 11 Oct 2007 15:01:56 -0500, Robert Swinney wrote:
Nick sez:

"You should lubricate your steel BBs with oil before switching to ceramics."

"BB", in the U.S. at least, describes a specific size of shot as used in welll, errrr, . . .
shotguns ! Doubtless such are ever found in bearings.


Also BB guns; I think in this case it's probably sort of slang for the
actual balls in a real bearing.

Did you hear about the ball-bearing mousetrap?

It's also known as the "tomcat". ;-)

Cheers!
Rich

"erik litchy" wrote in message
erio.net...
looking at that picture i cant imagine how those things are made.
since most ceramics shrink greatly when fired...

Most bearings of all types are made pretty much the same way: in a mill that
rolls them around in abrasive in a series of circular patterns. I wrote an
article about it once, if I can find the sucker.

--
Ed Huntress

According to Randy :
On Wed, 10 Oct 2007 20:10:16 -0500, Tim Wescott
wrote:

[ ... ]

All the preceding, plus they're insulating, which is handy in some
electromechanical applications.

Or bad in some applications, you may need some type of brush setup to
ground the rotating part or some serious static charge can build up.

Nice if you are using a lathe to rotate a workpiece while it is
being arc/tig/mig welded, however. You'll need to make some way to get
the power to the spindle, but you won't be burning up your bearings.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"Robert Swinney" wrote in message
...
Recently, I read somewhere about diesel engine experiments re. cylinder
walls being made of ceramic
material. This in order to reduce heat loss to the surroundings thus
retaining more "heat" within
the Diesel cycle.

Bob Swinney

Yes. And the first test models were built almost 30 years ago. I reported on
them in 1981. g

I also reported on ceramic turbochargers a year earlier than that. We don't
have them, either. What we do have is some ceramic coatings that reduce wear
on pistons and cylinders, but they aren't thick enough to do much
insulating, according to what I've read.

Advances have been made in the use of ceramics in heat engines but I view
them the same way I view solar-Stirling engines and photovoltaic cells: a
bundle of promise, always just over the horizon, that never quite delivers
the big results promised for them. The "promise" of ceramic cylinders and
pistons is to drive the whole thermal cycle 'way up the Carnot Cycle curve,
potentially to double engine efficiency.

Maybe someday. Ceramic bearings, though, are real and they're widely used in
the high-speed spindle range, faster than steel can take but slower than
pneumostatic can provide.

BTW, that method I described for producing bearing balls has been in use for
over 1,000 years, with few changes except in materials and in the way the
mill is powered. I'll see if I can find the article.

--
Ed Huntress


"Ed Huntress" wrote in message
...

"erik litchy" wrote in message
erio.net...
looking at that picture i cant imagine how those things are made.
since most ceramics shrink greatly when fired...

Most bearings of all types are made pretty much the same way: in a mill
that
rolls them around in abrasive in a series of circular patterns. I wrote an
article about it once, if I can find the sucker.

--
Ed Huntress

"Robert Swinney" wrote in message
...
Ed sez:

"Advances have been made in the use of ceramics in heat engines but I view
them the same way I view solar-Stirling engines and photovoltaic cells: a
bundle of promise, always just over the horizon, that never quite delivers
the big results promised for them. The "promise" of ceramic cylinders and
pistons is to drive the whole thermal cycle 'way up the Carnot Cycle
curve,
potentially to double engine efficiency."

Thanks Ed.

Yep! It seems the pie is always in the sky.

Your bearing article would make a nice read, I'm sure. We'd like to see
it.

Bob Swinney

OK, it was on my hard disk. This is from the "How It's Done" column I wrote
for Machine Shop Guide some years ago. I don't own the copyright to this but
I don't know who does anymore. Hoping they won't mind:

How It's Done
Machine Shop Guide


The Near-Perfect Sphere

By Ed Huntress, Senior Editor


Like water running from a faucet, or the first day of spring, bearing balls
are something we take for granted. They are as commonplace as a metal
product can be, with one exception: they're as near to dimensional
perfection as any mass-produced product we can think of, a perfection that's
achieved with a method that reaches back to a time when precision machining
meant making a screw fit into a nut: nearly 300 years ago.

But ball bearings started off on a more conventional tack. Until the end of
the 19th century, metal bearing balls were turned on lathes. English
manufacturers were turning steel rod into balls, producing accuracy on the
order of 0.025 mm (0.001 in.). A German bicycle mechanic, Friedrich Fischer,
son of the inventor of the pedal bicycle, developed a method near the
century's end that improved on this accuracy by taking a radically different
approach. He invented a machine that squeezed, ground and lapped balls
between two metal disks, one rotating and one stationary, running the balls
in circular grooves that were cut into the disks' faces. Around and around
the balls raced; by the law of averages, the balls were knocked into rough
shape, ground into precise spheres, and polished into near-perfect balls.

The invention revolutionized bearing manufacture and application, making
low-friction, high-speed ball bearings practical for the emerging generation
of high-speed machinery. The humble bearing ball was at the heart of high
technology and became a subject of military intrigue during World War I, a
commodity vital to the war efforts of both sides, akin to the intrigue and
competition that developed over more-glamorous industrial diamonds.

It's unclear whether Fischer was aware he had re-invented a method that had
been used centuries before for grinding balls of marble to high accuracy.
The ancient ball-grinding machines used one stone plate with grooves, much
like the plates used today, and a wooden driving plate, driven by a water
wheel, that rolled rough-hewn lumps of marble into balls accurate to 0.1 mm
(0.004 in.). The similarity in the basic mechanisms is remarkable.

Also remarkable is that today's ball-making machines use the same method.
Fischer's re-invention has been refined but not fundamentally changed. The
process begins with a slug of annealed wire, which is headed into a rough
ball with flash around its waist; rough balls are rolled between plates to
de-flash them; and then a varying number of steps of rolling produce the
final shape. When the balls are intended for use in conventional ball
bearings, they're hardened at an early stage in the rolling processes.

A modern ball making machine uses two plates, called rill plates, made of
cast iron or steel, with grooves cut to the radius of the balls, but with
depths of only 1/3 of the ball diameter. Vertical turret lathes are commonly
used to cut the grooves, which are specific for each ball size and type.

One rill plate is a complete circle and it rotates. The other, called the
gap plate, has a pie-shaped wedge cut out of it, and it remains stationary.
The balls enter the machine through this opening and the force of spinning
them around causes some to jump back out after a random number of circuits
around its groove. A chute and return system capture the balls as they're
thrown out and drop them back into the opening. There's no attempt to
control which of the many grooves the balls are dropped back into. In fact,
the process is intentionally random. It's the randomness and the statistical
equality in the way the balls are handled that makes them uniform and
accurate in finished size.

Hardened steel balls are not the only types made by this process. Balls of
other metals, ceramics, plastics, and even rubber are made the same way, for
a range of applications from air gun pellets to the balls in roll-on
deodorant sticks.

[Thanks to reader Mark Russell for suggesting that we take a roll at bearing
balls in "How It's Done," and to Noonan Machine Company for providing much
of the information.]

--end--

Ed Huntress wrote:

Yes. And the first test models were built almost 30 years ago. I reported
on them in 1981. g

G And I remember that I invented ceramic coating on the top of pistons.
That was in the early 80's. But then I had to realize that that idea was
given up some years before. :-)


Nick
--
The lowcost-DRO:
http://www.yadro.de

"Nick Mueller" wrote in message
...
Ed Huntress wrote:

Yes. And the first test models were built almost 30 years ago. I reported
on them in 1981. g

G And I remember that I invented ceramic coating on the top of pistons.
That was in the early 80's. But then I had to realize that that idea was
given up some years before. :-)

There's very little that hasn't been thought of in IC piston engines, I
believe. I keep thinking about it, and a million other people keep thinking
about it, but it seems likely we're all going around in the same circles.

However, it's still good for helping to put me to sleep on sleepless nights.

--
Ed Huntress

On Fri, 12 Oct 2007 09:26:59 -0400, "Ed Huntress"
wrote:


Advances have been made in the use of ceramics in heat engines but I view
them the same way I view solar-Stirling engines and photovoltaic cells: a
bundle of promise, always just over the horizon, that never quite delivers
the big results promised for them. The "promise" of ceramic cylinders and
pistons is to drive the whole thermal cycle 'way up the Carnot Cycle curve,
potentially to double engine efficiency.



Not quite what you are referring to, but Nikasil linings are fairly run of the
mill in light weight engines.


Mark Rand
RTFM

"Mark Rand" wrote in message
...
On Fri, 12 Oct 2007 09:26:59 -0400, "Ed Huntress"

wrote:


Advances have been made in the use of ceramics in heat engines but I view
them the same way I view solar-Stirling engines and photovoltaic cells: a
bundle of promise, always just over the horizon, that never quite delivers
the big results promised for them. The "promise" of ceramic cylinders and
pistons is to drive the whole thermal cycle 'way up the Carnot Cycle
curve,
potentially to double engine efficiency.



Not quite what you are referring to, but Nikasil linings are fairly run of
the
mill in light weight engines.

Yes, those are one of the two primary ceramic coatings. Not much insulating
going on, and, as far as I know, no increase in peak operating temperature.

But they're good for wear and friction.

--
Ed Huntress

"Robert Swinney" wrote in message
...
And they're all good ideas; all trying to improve the efficiency of heat
engines. It's been going
on since the day after Watt sobered up from the celebration. Trouble was
Carnot was not invited to
the party and he put a big mojo on everything.

BTW - thanx Ed. for the balls article.

My pleasure. I always liked doing articles with balls.

--
Ed Huntress