28 Nov
2008
28 Nov
'08
9:14 a.m.
On 27 Nov 2008 at 22:32, dwight elvey wrote:
If it gets pulled too far uneven, there won't be
enough tension on the narrow side to pull it back
and the belt will slip off. This effect can also
happen if the load is too large.
These effects can be demonstrated on disk drives.
But crowned pulleys work pretty much with any kind of belt. A belt
operating on a cone-shaped pulley will always position itself to the
largest possible diameter on the drive pulley, even if the belt's a
wide flat stiff one, such as leather.
While the belt may hug the smaller-diameter parts of the pulley due
to elasticity in the lateral axes, most rubber belts are made to be
relatively inelastic in the longitudinal axis. A belt with
significant longitudinal elasticity can be unstable in a driving
situation, which is why rubber bands work poorly as drive belts.
We may not settle this one for certain. The sure-fire way is to
measure what's going on, but I suspect the net difference between
your theory and mine will be exceeding small. Still, it's fun to jaw
about it.
Cheers,
Chuck