Need description of Helical Gear Crown

I would expect the involute crown to be
some sort of tip relief on or near the
tip of the gear. The lead crown would
allow shaft misalignment as you suggested.
The tip relief crown would allow for
deflections at the tip so that they would
not dig into their meshing dedendums and
reduce the arc of approach. This is a best
guess as to the involute crown profile.
Will be anxious to see other opinions.

Gear coupings use a crowned and barrelled tooth form to allow flexing and accomodate shaft misalignment between machine shafts.

Check out Koppers (Kopflex) website at for some technical articles about gear couplings.

They may be of help

CK

Errors of manufacture, deflections under loads prevent the true involute contact. In order to avoid the premature contact or eexcessive contact at the tips or roots, profile modifications are chosen. But other reason is to reduce the effect of these manufacturing /assembly errors so that less Gear whine is reduced. Stiudies have been conducted to find out the effect of invloute crowning on reducing the whine.

The shape can be circular or parabolic. Factors like load, gear geomtry etc. would decide which type and how much. Approx. 0.0004/0.0006 is standard involute crowning.

Please refer to the Gear solutions Magazine online issue 2004.

The lead crowning is prvided on for reducing the effects of axial misalignment in shaft gears and to avoid end loading in helical and spur gears.

You may want to go to and search for the keyword crowning. It will give you the past Gear technology issues on this subject and which you may want to purchase.