The behaviour of rotating machinery during deceleration when the power of the drive to the rotating machinery is stopped is known as Coast Down Phenomenon (CDP). The total time elapsed for the entire momentum due to sustained operation of the rotating machinery to dissipate is known as Coast Down Time (CDT). The characteristic profile of CDT (CDT-P) depends on inertia forces of the machinery components, tribological behaviour and environmental effects such as fluid drag. The aim of the research is to investigate the potential and the feasibiJity of using CDT as an effective tool for condition monitoring of machinery. A review of current literature has given a clear understanding to what extent the CDP has been explored with respect to utilising it as a diagnostic parameter. However no evidence for effective use of CDT in condition based monitoring programmes can be found. The main focus of this research is concentrated on ascertaining the validity of Coast Down Time as one of the condition monitoring parameters for a horizontal rotor system. Extensive experimental analysis is conducted on a rotor system consisting of a journal bearing using different lubricants under various mechanical and operating conditions An empirical formula is developed to determine the Coast Down Factor (CDF). Furthermore, the effect of rub on the motor has been studied with the aid of an electromagnetic clutch and isolating the rotor from the drive system. This research has shown a novel way to interpret the CDT-P to be used as a diagnostic parameter in condition monitoring by the formulation of Coast Down Factor. CDF gives a simple, but highly flexible tool for CDT analysis. COT monitoring through the trend of CDF can be used to analyse the performance of a journal bearing under given tribological conditions; to utilise as a tool for optimisation of selection of lubrication oil; to evaluate and understand. the tribological behaviour of lubrication and the performance of a journal bearing under different oil pressures; and to diagnose the mechanical degradation with simulated unbalance to the rotor system.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:486489 |
| Date | January 2008 |
| Creators | Browne, R. Edwin |
| Publisher | Glasgow Caledonian University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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