Machinery Lubrication

Machinery Lubrication July August 2015

Machinery Lubrication magazine published by Noria Corporation

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24 July-August 2015 | www.machinerylubrication.com BY DAVID KINTNER JR., LEPRINO FOODS The hardest part of starting a reliability program is freeing up time to work on proactive tasks. The mainte- nance department at Leprino Foods spent most of its time repairing broken equipment. The technicians were so busy that they didn't have time to think about how to proactively solve their issues. There was a lack of organization. Too much time was spent looking for original equipment manufacturer (OEM) manuals, searching for parts and troubleshooting equipment. Slowly the idea of working smarter not harder was introduced. For instance, instead of hunting for OEM manuals in an unorga- nized drawer in the parts room, parts and other items were scanned and searched for electronically. The technicians worked on their troubleshooting techniques to shorten the time it took to make repairs and minimize the mistakes they were making. The idea of asking why was encouraged. Why were a high number of motor and AC drive failures being experienced? Why were gearboxes failing? Why was there an excessive amount of grease in the windings in almost all the motors that were inspected after failure? The technicians were accustomed to removing a motor, putting a repair tag on it and turning it over to the parts room to be sent out for repair before moving onto the next asset. This remains a learning process. Considerable time was spent demonstrating how a proactive mindset can make all the differ- ence. Through experience, it was learned that most moderate to complex issues could be rooted all the way back to the most basic task. For example, a bearing may be undergreased or overgreased. The wrong lubrication may also be used on the wrong application. Starting with the Worst Actors The worst actors had to be addressed in the plant. Utilizing a computerized maintenance management system (CMMS), the functional locations that seemed to have the biggest issues were identifi ed along with the most damaging failure modes. One case study from the plant in Allendale, Michigan, involved a whey-powder dryer system. The plant was experiencing premature bearing failure with all six of the dryer exhaust fans and was lucky to get a year of service life from the load and motor bearings. After a failure analysis was performed, an action register was selected and a multitude of issues began to be addressed, such as researching and observing installation, lubrication, loading and precision main- tenance practices. Some of the issues discovered were incorrect bearing installation, bearing overgreasing, improper belt tensioning and incorrect sheave alignments. During installation, it was determined that the bearings weren't being gapped properly on the shaft. The initial amount of grease applied to the bearing housing was also excessive. Every- thing was a "hurry-up" situation, so the belts were never tensioned properly, nor were the sheaves aligned. In fact, the V-belts were replaced a couple of years ago, so the correct tensioning gauges were not even in-house. An experienced application engineer was brought in to analyze this problem along with some other areas that had lubrication application concerns. It was soon realized that all of the technicians and managing personnel believed that more grease was always better. The plant was also caught in the trap of trying to use one grease for all of its bearing applications. MAINTENANCE & RELIABILIT Y Reliability Program Should Look Like What a Maintenance The majority of failures were caused by overgreasing, un- dergreasing, overtensioning belts, sheave misalignment, shaft misalignment, imbalance, etc. Powder buildup in the motor seal area was caused by clearance in the seal, which was likely due to an overten- sioned belt. Once the seal wore out, ingression was inevitable.

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