The foundation of reliability is condition monitoring. Without condition monitoring the steps necessary to improve machine reliability are feeble at best. The implementation of condition monitoring strategies must indicate the required maintenance which should be done. If all of the measurements of condition monitoring are within acceptable ranges then there is no need to perform maintenance on the machine. If maintenance is still required then additional condition monitoring strategies must be implemented.
To understand the mechanical condition of machinery the vibration signature must be measured. Art Crawford said, “Of the all the parameters which can be measured on a machine, the measurement with the most information about the mechanical condition is the vibration measurement”.
This technology measures and compares over time the temperature profile of the machinery being measured. It can identify “hotspots” in electrical, mechanical, hydraulic or any system which shows heat as an indicator of deteriorating health.
If there is lubrication oil that is part of the machine system, then oil analysis can be done to help understand the mechanical health of the machine. The oil analysis values must be stored and trending of the values must be done. Typically done on gearboxes, hydraulic systems, large engines and any system with an oil filter.
Non Destructive Testing (NDT):
These technologies use various methods to measure the structural integrity of machine systems. It can identify the extent of cracking, wall thickness erosion, gear-tooth health etc. The techniques of NDT are; magnetic particle inspections, dye penetrant, ultrasonic, strain, crack monitoring and Eddy Current Array measurements.
The operational history of a machine can indicate and assist in increasing the reliability of the machine. This is condition monitoring by capturing feedback from the skilled craftsmen as they perform maintenance, from the operators as they gain knowledge from being around and operating the machines then compiling the information into a usable and accessible format.
These activities include many strategies to improve the long-term reliability of the machines. Examples of some of the strategies are; balancing, machine shaft alignment, root cause failure analysis, structural modal analysis and scheduled preventive maintenance (PM) activities.
Return on Investment (ROI):
The cost to implement condition monitoring strategies typically look like this, however, the return on investment becomes an ongoing real reduction in maintenance costs.