On Mar 3, 5:52*pm, Ecnerwal
wrote:
...
For a vague idea of what's involved, consider that my bucket is rated to
produce 9000 lbs of force at the edge - which is about 2 feet from the
pivot. The cylinder is less than a foot away on the other side, so it
has to be putting 18,000 lbs into the bucket pins, and the pivot itself
gets some large force that's not immediately obvious, but might be as
much as 27,000 lbs...on a pin that's about and inch and half diameter,
with the bearing on the bucket only 1-1/4 inch long on either side of
the dipper-stick.

18000 / (1.5 * 2.5) = 4800 PSI. When I designed my front end loader I
looked for examples of bearing pressure and found as much as 9000, on
a swinging bridge pivot. I kept mine to 2000 to allow brass pipe
bushings, the max for sintered oilite is lower. It operates at half
the design load which blew the front tires.

Jim Wilkins