Andymark Hex Bearing Trouble

[henryBsick]

Originally Posted by Andy Baker

We are realizing that the inner race of this bearing is very thin, and cannot handle a heavy side load very well. We are working on this issue now, and will give some feedback this week.

Andy B.

This was my guess as to their failure method. Upon receiving the bearings I realized the inner races were similar in size to normal 3/8" inner races, just with a hex bore; I expected to see a thicker inner race to support the material cleared by the hex cutout. The hex as Andy has pointed out causes six points of very low wall thickness. The first bearing to go failed under normal operation with winch drum in place with minimal side loading. The second bearing failed once the drum was removed for a reduction in wrap diameter to provide more torque. With the bare axle exposed the rope stacks as it is wound and is contained side to side by the bearing itself, thus causing side loading. I had assumed that the forces involved would not be enough to damage the bearings, I was partially correct. The standard 3/8" ID bearings were fine, AM inner race in pieces.

I can grab pics once I'm in the lab this Tuesday.


-Henry