Re: [CAD_CAM_EDM_DRO] Re: Tapered Roller / Angular Contact Bearings(what is dn)

Hi,

This is one of the problems with using roller bearings - they aren't
designed to run at such high speeds as ball races. Its not a problem for
things such as leadscrew bearings but is something you maybe need to
consider if you think of using them on a cutting spindle like in a router -
run 'em too fast and they will heat up, expand, sieze and wreck themselves.

Ian
--
Ian W. Wright
Sheffield UK

----- Original Message -----
From: <ballendo@...>
To: <CAD_CAM_EDM_DRO@egroups.com>
Sent: 28 October 2000 04:27
Subject: [CAD_CAM_EDM_DRO] Re: Tapered Roller / Angular Contact
Bearings(what is dn)


> Jan wrote:
> >Don't keep us ALL guessing! What are "DN's"???
>
> Jan,
>
> I was going to guess Dynamic Newtons. But I thought I'd ck the net:
>
> From:
>
> http://www.lerc.nasa.gov/WWW/RT1995/5000/5230k.htm
>
> "They could also increase the DN (diameter of the bearing times rpm)
> limit on engine speed"
>
> And from:
>
> http://www.techno-isel.com/Tic/H830/HTML/H830P022.htm
>
> "A useful guide for ball bearing selection is to consider the DN
> value (speed value) of the bearing. The DN value is the product of
> the bore size (mm) and the shaft speed (rpm)."
>
> So now we know.
>
> Ballendo
>
>
> http://www.techno-isel.com/Tic/H830/HTML/H830P022.htm
>
>
>
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