Machinery Lubrication magazine published by Noria Corporation
Issue link: https://www.e-digitaleditions.com/i/1206285
8 | January - February 2020 | www . machinerylubrication.com Vibration and oil analysis are two highly effective predictive mainte- nance techniques that have been used for decades. Other techniques such as thermography and sensory inspections can be applied to maintenance as well. However, to determine the most appropriate maintenance actions, it is necessary to analyze each asset and consider various perspectives. Vibration Analysis Vibration analysis has been described by many as the best way to detect machine failure, including the degree of severity. It also is used as a tool to validate the acceptance of a machine after it has undergone some intervention. Vibration analysis can be applied to various types of rotating assets, such as electric motors, pumps, reducers, fans, power generators, compressors, turbines, etc. It is an excellent tool to identify misalignment, unbalance, mechanical clearances, belt defects, warped shafts, defective bearings and gears, cavitation, lubrication defects, etc. In more advanced applications, it is possible to identify resonance in static structures. Vibration analysis offers many benefits, as the non-destructive or non-invasive techniques cover nearly 80 percent of a plant's machinery. With the results, maintenance teams can drive a variety of improvements, such as better foundation conditions, proper alignment, improved balance quality, and reduced or even eliminated chronic machine problems. Several vibration analysis tools can be used based on the characteristics of the machines, such as kurtosis, fast Fourier transform (FFT), envelope analysis, spectrum analysis, etc. ese tools can be applied according to the fault modes you wish to monitor. Each failure mode is identified in the spectrum by the displayed symptoms. For example, unbalance is characterized by one times (1x) the rotation, while misalignment is classically identified by one and two times (1x and 2x) the rotation. A very common symptom is the presence of a high-spectrum carpet value, which always COVER STORY By Ray Garvey, Asset Analytix Oil Analysis or Vibration Analysis? Which Is Better and When to Use Each Technique By Martim de Lima Pereira and Renato Augusto dos Anjos Rito