Mysterious & Costly Problem Solved by Torque Measurements

Mysterious (and Costly) Problem Solved by Torque Measurements

A Brazilian gear box manufacturer had a mystery to solve in the giant drive system of a Brazilian sugar cane processing mill. The coupling at the gear box is a special "overload coupling" and it broke repeatedly during the routine sugar mill process. The special coupling has a mechanical torque limiter to prevent overload, but the limiter never activated. The gearbox itself was not damaged.

"What is going on?" That, of course, was the primary question.

Trying to find the cause of the broken couplings, the gear box manufacturer called in our Brazilian agent, Torkex Transmissões Industriais Ltda, who installed the TorqueTrak 10K telemetry instrument plus Op-Torq FIELD TEST 2 data acquisition system to measure and analyze the true mechanical load of the sugar milling process. Look closely at these photos above and you will see the torque pattern strain gage plus TorqueTrak 10K Transmitter and 9V Battery installed on the giant rotating shaft.

They expected to find high torque spikes in the milling process, high enough to break the couplings. But to their surprise, they found no torque spikes. In fact, there were no overloads at all. The process load proved to be well within design limits. This interesting discovery prompted the gear box manufacturer to contact the manufacturer of the special "overload coupling", who then performed some tests and found the problem to be the coupling material itself. What a surprise! In the end, everybody was satised that they had correctly diagnosed the problem and they now knew what corrective action to put in place.