Influence of bearing clearance and oil temperature uncertainties on the stability threshold of cylindrical journal bearings

Analysis of wear debris, vibration and temperature of journal bearing has been integrated to increase the accuracy in fault diagnosis of a hydropower plant. Samples of used lubricating oil, vibration data and bearing temperature at different intervals were collected. Wear particles and acceleration caused by vibration were analysed for the fault detections. An abnormal increase in the temperature and vibrational energy was observed after 200 days of continuous operations. In the last sample, an abnormal increase in aspect ratio of the wear particles was also observed. Scratches and wiping mark were found over the surface of bearing block and side thrust pad. This confirmed the fault of machine by the analysis of condition monitoring data. Further rectification was done by the replacement of bearing block.

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“…It was verified that the influence of radial clearance was more than oil temperature for stability of bearing. 20…”

Section: Introductionmentioning

confidence: 99%

Fault diagnosis of journal bearing in a hydropower plant using wear debris, vibration and temperature analysis: A case study

Ranjan

Ghosh

Kumar³

2020

Proceedings of the Institution of Mechanical Engineers, Part E:

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“…e fit clearance exists widely in bearing systems and causes nonlinear dynamic behaviors inevitably [17]. Chen and Qu [18] studied the effect of fit clearance on the vibration response and pointed out that the fit clearance led to the periodic contact between the outer ring and the pedestal.…”

Section: Introductionmentioning

confidence: 99%

Raceway Defect Frequency Deviation of Full‐Ceramic Ball Bearing Induced by Fit Clearance in Wide Temperature Ranges

Bai

Zheng

Wang

et al. 2021

Shock and Vibration

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Full-ceramic ball bearings are widely applied in wide temperature ranges due to their excellent thermal shock resistance, and the condition monitoring and fault diagnosis are mainly conducted through the spectrum analysis based on the defect frequencies. However, the outer ring has a spinning motion in the temperature-related fit clearance, which leads to the deviation of raceway defect frequencies, and is not conducive to the fault diagnosis. In this paper, the temperature-related fit clearance is considered in the dynamic model, and defects are added on the inner raceway and outer raceway. The motions of the rings are calculated and analyzed in the frequency domain, and the trends of peak frequencies with temperature are investigated. Simulation and experimental results show that the spinning speed of the outer ring increases with temperature, and the defect frequencies exhibit obvious deviation in wide temperature ranges. In a temperature range of 500 K, the defect frequencies exhibit deviations of over 3%, which is obvious in the defect frequency identification. The results provide insights on the full-ceramic ball bearing dynamics and help with the fault diagnosis and status monitoring of the relevant devices.

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“…The stable operation of JB requires the clearance not to exceed the operating boundaries. If the clearance is out of bounds, mechanical instabilities in the shaft rotation, such as oil whirl, oil whip, looseness, or journal-tobearing contact can arise [10,11]. Mechanical stress due to these instabilities can also cause damage on the bearing babbitt surface, particularity, the oil whip is an unsafe operation that may cause severe damage on the machine [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

“…If the clearance is out of bounds, mechanical instabilities in the shaft rotation, such as oil whirl, oil whip, looseness, or journal-tobearing contact can arise [10,11]. Mechanical stress due to these instabilities can also cause damage on the bearing babbitt surface, particularity, the oil whip is an unsafe operation that may cause severe damage on the machine [9][10][11]. Journal bearings are inspected during the maintenance process by a clearance measuring procedure, as well as an accurate examination of the babbitt surface; if a high-level damage occurs then a re-babbitting procedure will be necessary.…”

Section: Introductionmentioning

confidence: 99%

Identification of Babbitt Damage and Excessive Clearance in Journal Bearings through an Intelligent Recognition Approach

Gómez¹,

Montero²,

Gomez-Mancilla³

et al. 2021

IJACSA

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Journal bearings play an important role on many rotating machines placed on industrial environments, especially in steam turbines of thermoelectric power plants. Babbitt damage (BD) and excessive clearance (C) are usual faults of steam turbine journal bearings. This paper is focused on achieving an effective identification of these faults through an intelligent recognition approach. The work was carried out through the processing of real data obtained from an industrial environment. In this work, a feature selection procedure was applied in order to choose the features more suitable to identify the faults. This feature selection procedure was performed through the computation of typical testors, which allows working with both quantitative and qualitative features. The classification tasks were carried out by using Nearest Neighbors, Voting Algorithm, Naïve Associative Classifier and Assisted Classification for Imbalance Data techniques. Several performance measures were computed and used in order to assess the classification effectiveness. The achieved results (e.g., six performance measures were above 0.998) showed the convenience of applying pattern recognition techniques to the automatic identification of BD and C.

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Influence of bearing clearance and oil temperature uncertainties on the stability threshold of cylindrical journal bearings

Cited by 40 publications

References 31 publications

Fault diagnosis of journal bearing in a hydropower plant using wear debris, vibration and temperature analysis: A case study

Fault diagnosis of journal bearing in a hydropower plant using wear debris, vibration and temperature analysis: A case study

Raceway Defect Frequency Deviation of Full‐Ceramic Ball Bearing Induced by Fit Clearance in Wide Temperature Ranges

Identification of Babbitt Damage and Excessive Clearance in Journal Bearings through an Intelligent Recognition Approach

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