Everyone knows what Preventative Maintenance is: service to equipment to "prevent" it from premature failure. But not everyone understands that PM must be tailored to each piece of equipment. Some equipment may require PM service that might take as little as 10 minutes. Other larger equipment may take days to complete the PM. Each manufacturer has his own recommendations for PM service, and it must be followed.
Lubrication is generally the most essential check to be sure it is right. Whether it is draining all of the old oil and refilling with fresh, or just giving bearings a shot or 2 of grease, the original manufacturer's recommended procedures for PM is the usually the best bet. The bearings are relatively high precision components that must be properly cared for to prevent failure.
Preventative maintenance starts with the initial installation of the equipment. Many engineers and equipment manufacturers', are now recognizing this as more important as they specify additional measures such as laser shaft alignment, baseline vibration data collection, and even system resonance testing.
Shaft misalignment, referred by most as "coupling misalignment", can shorten the life of the equipment by years! Most often by premature bearing failure. The loose internal fit of ball bearings is always less than .001". If the shafts are say .010" - .015" "misaligned", than the coupling has to pull the shaft back to that .001" centerline, which puts pressure/stress on the precision bearing, the shaft, and the seals. Flex coupling elements absorb some of that pressure, but it is always still there pushing on the bearing.
A small paper company in eastern NY used me to prove this. I was being called in during their scheduled shutdowns every month to laser align their pumps after they replaced the seals & bearings. After 6 months, the pump failures were greatly decreased, and I was asked to visit quarterly. Another 6 months later, as the failures decreased even more, they would "call me" if needed. A couple of years later, I no longer visit there at all! Pump seals and bearings last years, now! They have since purchased their own laser for shaft alignment.
Regular vibration data collection can easily be justified because a trained technician can identify bearing wear, machine resonance, imbalance, misalignment, and many other abnormalities long before the machine starts vibrating excessively. It is no wonder vibration analysis is the #1 tool for preventative maintenance.
Is vibration analysis in your toolbox? It should be. Invest in PM, it will save you money!
