DIYbanter - "schiele curve"

William Noble wrote:

I am trying to find a definition of this curve, which is described in old
lathe design manuals - not finding anything on the internet - any of you
guys have a good reference?

"Tractrix. The curve known as a tractrix, frequently also called the
"Schiele" curve or the "anti-friction" curve, has been supposed to
give the correct outline for an end-thrust bearing, because the wear
in the direction of the axis of the thrust shaft will be uniform at all
points when the pivot is given the form determined by this curve.
It has been shown, however, that the merits of a pivot bearing shaped
in this manner have been greatly over-estimated; and the term
"anti-friction," applied to the curve, is a misnomer, since the friction
of the bearing designed in accordance with it is greater than that of a
flat step or collar of the same diameter."
Vol 2 Engineering Encyclopedia IP

There's plenty on the net as regards "tractrix"

Tom

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