I have asked bearing engineers about this in an e-mail with no
response. Surely someone here can provide the correct answer. There
are three types of rolling element thrust bearings that I am very
familiar with. The first uses balls. I understand how these work. The
second type uses tapered rollers and conical races. I understand these
too. But the third type uses flat races and straight cylindrical
rollers. The load they can take is quite high. But the rollers must
skid. Why doesn't this ruin the bearings? And why doesn't this
skidding cause high friction?
Thanks,
ERS

Eric R Snow wrote:

I have asked bearing engineers about this in an e-mail with no
response. Surely someone here can provide the correct answer. There
are three types of rolling element thrust bearings that I am very
familiar with. The first uses balls. I understand how these work. The
second type uses tapered rollers and conical races. I understand these
too. But the third type uses flat races and straight cylindrical
rollers. The load they can take is quite high. But the rollers must
skid. Why doesn't this ruin the bearings? And why doesn't this
skidding cause high friction?
Thanks,
ERS

the ones I've seen have a slight taper on the roller.

John

Greg please post a picture and when you do let use know here. You must be
very close to the Bridgeport ferry, there are many in this group from the
area. I live in CT.
"Greg" wrote in message
ups.com...
Eric
They do skid but they can run along time at near rated load with no
apreciable wear. I use this style bearing in some very large spinning
machines and they have lasted multiple years. The best designs are the
ones that torrington used, they use a 2 segment roller where one roller
is longer than the other. Then each set of rollers is flipped so that
the long one is alternated to top or bottom position. That way they
track differently. Some of the ones I use have a 5" ID and a 7" OD with
a load capacity of 135,000 pounds. They work their asses off in the
machines we use to spin Taper aluminum extrusions into lightpoles and
flagpoles. I've got these machine running 15 hours a day 6 days a week
now and those bearings are the last thing I am worried about now. The
most extreme setup runs with 100 Horsepower on the spindle and nearly
100,000 pounds of force on the the carriage. The machine uses a world
war 2 gun boring lathe as the skeleton and everything else is unique.
Some day i'll post a picture on the website www.pkpole.com part of the
problem with getting information from the bearing manufacturers is that
the industry is becoming two companys with all the buyouts. Don't even
get me started on how pricing and availability has turned to crap.

Greg
John wrote:
Eric R Snow wrote:

I have asked bearing engineers about this in an e-mail with no
response. Surely someone here can provide the correct answer. There
are three types of rolling element thrust bearings that I am very
familiar with. The first uses balls. I understand how these work. The
second type uses tapered rollers and conical races. I understand these
too. But the third type uses flat races and straight cylindrical
rollers. The load they can take is quite high. But the rollers must
skid. Why doesn't this ruin the bearings? And why doesn't this
skidding cause high friction?
Thanks,
ERS

the ones I've seen have a slight taper on the roller.

John

Greg

Some day i'll post a picture on the website www.pkpole.com part of the
problem with getting information from the bearing manufacturers is that

the industry is becoming two companys with all the buyouts. Don't even
get me started on how pricing and availability has turned to crap.

I looked at your site. You must have a power bill that has no limit.
Care to share? And some pictures would be interesting.

On Sun, 26 Feb 2006 20:11:52 -0500, John
wrote:

Eric R Snow wrote:

I have asked bearing engineers about this in an e-mail with no
response. Surely someone here can provide the correct answer. There
are three types of rolling element thrust bearings that I am very
familiar with. The first uses balls. I understand how these work. The
second type uses tapered rollers and conical races. I understand these
too. But the third type uses flat races and straight cylindrical
rollers. The load they can take is quite high. But the rollers must
skid. Why doesn't this ruin the bearings? And why doesn't this
skidding cause high friction?
Thanks,
ERS

the ones I've seen have a slight taper on the roller.

John
Greetings John,
You are correct. The needles, which are 5mm long (.19685"), are
..0002" smaller on the inside diameter. The washers (races) are thinner
on the inside too. .0002" thinner to be exact. So that adds up to
..0006". When I had measured these before I did it so quickly that I
didn't notice the .0002" difference. I thought the difference would
need to be much more than .0002". Guess that shows, once again, that
before I assume something I need to be sure I have all the facts.
Thanks,
Eric