Measurement of roller load, load variation, and lubrication in a wind turbine gearbox high speed shaft bearing in the field

Nicholas, Gary; Howard, Thomas P.; Long, Hui; Wheals, J. C.; Dwyer-Joyce, R. S.

doi:10.1016/j.triboint.2020.106322

Cited by 45 publications

(18 citation statements)

References 16 publications

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“…The instrumented wind turbine has a Hansen EH55G21S-BN-50 3-stage planetary gearbox with a gear ratio of 1:50 and maximum HSS speed of 1550 RPM. As explained in [30], bearing instrumentation was conducted alongside a scheduled gearbox maintenance which necessitates its removal and transportation off-site, allowing access to the HSS bearing.…”

Section: Wind Turbine High-speed Shaft Gearbox Bearing Field Testmentioning

confidence: 99%

“…Data processing for reflection coefficient measurements is well documented in [22,30,37] and so will be explained only briefly here. Figure 7 shows raw ultrasonic reflections obtained from various interfaces within the bearing.…”

Section: Analysis Proceduresmentioning

confidence: 99%

“…After a period of time, the R values gradually transitioned from unity to 0.95 and remained at 0.95 until the subsequent roller traverses across the sensor. This transitional regime is categorized as D. The time at which the reflection coefficient transitioned from unity to 0.95 after a roller pass is termed "lubricant reflow time" [30]. This recurring "zig-zag" pattern captures the behavior of the lubricant within the bearing and forms the basis which the lubrication condition of the roller is inferred.…”

Section: Analysis Proceduresmentioning

confidence: 99%

“…The minimum thickness of free surface lubricant film required to register a reflection coefficient of 0.95 is currently subject to further investigation. As explained in [30], it is theorized that with an increase in free surface film thickness, the reflection coefficient for a clean raceway surface will decrease from unity to 0.95. The frequency of the ultrasonic sensor will also have an effect as a free surface lubricant film smaller than one-tenth of the pulse wavelength (~60 microns) will not be registered and subsequently mirrors a steel-air condition (R = 1).…”

Section: Limitations and Assumptionsmentioning

confidence: 99%

“…This is followed by analysis of data from a field operational HSS gearbox bearing from a Vestas V42 600 kW wind turbine. Ultrasonic trends within a single dataset from the latter field operational bearing were previously presented in [30] to explore the detectable conditions of bearing load and lubrication. In this work, the full range of data covering a wide range of turbine operating conditions has been examined to establish how bearing lubrication is affected.…”

Section: Introductionmentioning

confidence: 99%

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Detection of Lubrication State in a Field Operational Wind Turbine Gearbox Bearing Using Ultrasonic Reflectometry

2021

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Fully flooded lubrication is the ideal state for a rolling bearing; this is especially true in the aggressive environment of a wind turbine transmission where bearings are subject to intermittent operation and highly variable loading. In this paper, a novel ultrasonic reflection method is used to detect the presence of oil between rollers in the bearing. Ultrasonic sensors were instrumented on the static inner (lab) and outer (field) bearing raceways and reflections were captured as the rollers travelled past the sensor. The proportion of the sound wave reflected (known as the reflection coefficient, R) is dependent on the acoustic mismatch of the materials either side of the interface. Changes in R indicate either a steel–air or steel–oil interface as R values transitioned from 1 to 0.95, respectively, and even lower for a steel–roller interface. Consequently, it was possible to detect the presence of lubricant on the raceway between roller passes. From the laboratory measurements, the recurring reflection coefficient patterns between roller passes were used to identify the lubrication condition of the raceway. An absence of these patterns between roller passes indicated the absence of lubricant on the bearing surface. For the field measurements, three bearing lubrication conditions (partial, insufficient, and fully lubricated) were observed. Partially and insufficiently lubricated datasets were found to occur mostly during transient operation. As transient operation is often accompanied by overloading and torque reversals, coupled with the lubrication issues, these all act to increase the risk of premature bearing failure.

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Section: Wind Turbine High-speed Shaft Gearbox Bearing Field Testmentioning

confidence: 99%

Section: Analysis Proceduresmentioning

confidence: 99%

Section: Analysis Proceduresmentioning

confidence: 99%

Section: Limitations and Assumptionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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