Wind Turbine Tribology

Terrell, Elon J.; Needelman, William M.; Kyle, Jonathan P.

doi:10.1007/978-3-642-23681-5_18

Cited by 9 publications

(7 citation statements)

References 61 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Usually four point bearings are used as yaw bearings [24,30] as shown in Figure 1. Double-row four point bearings have the advantages of a better stress distribution and higher lifetime but are also more expensive [30].…”

Section: Yaw Bearingmentioning

confidence: 99%

See 1 more Smart Citation

Yaw Systems for wind turbines – Overview of concepts, current challenges and design methods

Kim

Dalhoff

2014

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Abstract. Looking at the upscaling of the rotor diameter not only the loss in power production but the aerodynamic loads arising from yaw misalignment will have an increasing impact on the yaw system design in future wind turbines. This paper presents an overview of yaw systems used in current wind turbines and a review of patents with regards to the yaw system. The current state of the art of yaw systems has been analyzed through a systematic literature review. Further a patent analysis has been done through the European Patent Office. Todays design and strength requirements as per IEC and GL standards will be reviewed and alternative design calculations will be discussed. Over 100 patents have been identified as relevant to the yaw system and have been analyzed. It has been found that most patents are dealing with load reduction possibilities on the yaw system, where fatigue loads seem more of a problem than ultimate loads. Most of these patents concern especially the yaw actuator, which consists of multiple electrical motors, reduction gears and shaft pinions. This is due to the nature of the gearing in the actuator and the gearing between the shaft pinion and the ring gear. This coincides with the patents for yaw brakes, which mostly aim to reduce the fatigue loads during yaw maneuverer and during nacelle standstill. Patents for the yaw bearing are incorporating the reduction of loads through the usage of friction bearings or different bearing arrangement approaches. The paper shows that the conventional yaw system designs are still trying to meet the high requirements regarding the lifetime of a wind turbine and turbulent wind loads. New designs for yaw systems in general are hard to find. Many patents concentrate on control algorithms that depend on additional instruments and incorporate electromechanical systems.

show abstract

Section: Yaw Bearingmentioning

confidence: 99%

“…Double-row four point bearings have the advantages of a better stress distribution and higher lifetime but are also more expensive [30]. In contrast to ball bearings, sliding bearings have braking and damping properties which can make additional yaw brakes unnecessary.…”

Section: Yaw Bearingmentioning

confidence: 99%

Yaw Systems for wind turbines – Overview of concepts, current challenges and design methods

Kim

Dalhoff

2014

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…Water contamination in lubricants, on the other hand, was reported to significantly reduce bearings life . The presence of a mixture of water and fresh metal debris, especially copper and iron, were reported to promote the formation of free radicals and intensely accelerate oil oxidation as reported by Abner and cited in Terrell et al Moreover, it was shown that wear‐generated nascent metal surfaces and tribofilms create ideal sites for hydrogen adsorption …”

Section: Introductionmentioning

confidence: 94%

Tribochemical degradation of vacuum‐stable lubricants: A comparative study between multialkylated cyclopentane and perfluoropolyether in a vacuum ball‐on‐disc and full‐bearing tests

Kürten

Khader

Kailer

2020

Lubrication Science

View full text Add to dashboard Cite

In this study, the decomposition of a multialkylated cyclopentane (MAC) and a perfluoro-poly-ether (PFPE) lubricant was investigated in a ball-on-disc sliding test under vacuum and in a rolling contact fatigue (RCF) test on full bearings. In situ mass spectrometry was conducted to study the tribochemical formation of hydrogen in a steel-on-steel ball-on-disc sliding contact. Further investigations on lubricant degradation in rolling-sliding contact indicated fragmentation and oxidation reaction of the MAC oil by interaction with the oxide layer and the nascent bearing steel. Finite element method (FEM) analysis was carried out to model the contact in the ball-on-disc experiments and to extract contact surface temperature fields. Post-RCF hydrogen analysis of bearing components indicated increased hydrogen content in the samples lubricated with the MAC fluid. The RCF tests with PFPE did not indicate any signs of surface damage. K E Y W O R D Sball-on-disc sliding test, cylindrical roller thrust bearings, hydrogen, lubricant degradation, lubrication, rolling contact fatigue, vacuum tribology

show abstract

“…Figure 13.2.1 shows a photograph of wind turbine blades. Tribological issues in wind turbines include failure of the mainshaft and gearbox bearings and gears, water contamination, electric arcing on generator bearings, and the erosion of blades (due to solid particles, cavitation, rain, hail stones) (Kotzalas and Doll, 2010;Wood et al, 2010;Terrell et al, 2012). The hub is attached to the nacelle which houses the gear box, the drive train, the support bearings, and the generator.…”

Section: Renewable Energymentioning

confidence: 99%

Green Tribology and Biomimetics

Bhushan¹

2013

Introduction to Tribology

View full text Add to dashboard Cite

Wind Turbine Tribology

Cited by 9 publications

References 61 publications

Yaw Systems for wind turbines – Overview of concepts, current challenges and design methods

Yaw Systems for wind turbines – Overview of concepts, current challenges and design methods

Tribochemical degradation of vacuum‐stable lubricants: A comparative study between multialkylated cyclopentane and perfluoropolyether in a vacuum ball‐on‐disc and full‐bearing tests

Green Tribology and Biomimetics

Contact Info

Product

Resources

About