PROBLEM

A large grinding mill suffered from sporadic overloads during jam ups. Originally, without any form of overload protection, the pinion shaft would fail.

It was decided to add a shear pin protection device. This did protect the equipment, however it did not eliminate the down time and lost production.

SOLUTION

A close review of the system allowed us to identify the maximum acceptable torque for the power train. We were then able to design a friction device that would consistently give at the upper limit.

We also studied their operating cycle to determine the amount of energy we would need to absorb.

Covering these two key parameters allowed us to come up with a device that would slip momentarily during peak overloads, and then continue as the torque drops back down to an acceptable level.

This approach eliminated equipment damage, while significantly reducing lost production.