Investigation of Roller Sliding in Wind Turbine Gearbox High-speed-shaft Bearings PDF Download

Author: David Vaes
Publisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 22

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Author: David Vaes
Publisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 27

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Author: Yi Guo (Research engineer)
Publisher:
ISBN:
Category : Renewable energy
Languages : en
Pages : 22

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Author:
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ISBN:
Category :
Languages : en
Pages :

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Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

Author:
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ISBN:
Category :
Languages : en
Pages : 0

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The most prevalent failure modes in wind turbine drivetrains are main bearing failures stemming from micropitting, white etching or axial cracks in gearbox bearings, and generator bearing failures. These failures are neither well understood nor accounted for in design standards; consequently, the mitigation strategies being developed and fielded may only partially address the physics of failure and can take years to assess. The U.S. Department of Energy continues to support research programs to investigate the influence of rolling element sliding on the formation of bearing axial cracks and main bearing micropitting.

Author: Wiesław Ostachowicz
Publisher: Springer
ISBN: 3319390953
Category : Technology & Engineering
Languages : en
Pages : 432

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This book provides a holistic, interdisciplinary overview of offshore wind energy, and is a must-read for advanced researchers. Topics, from the design and analysis of future turbines, to the decommissioning of wind farms, are covered. The scope of the work ranges from analytical, numerical and experimental advancements in structural and fluid mechanics, to novel developments in risk, safety & reliability engineering for offshore wind.The core objective of the current work is to make offshore wind energy more competitive, by improving the reliability, and operations and maintenance (O&M) strategies of wind turbines. The research was carried out under the auspices of the EU-funded project, MARE-WINT. The project provided a unique opportunity for a group of researchers to work closely together, undergo multidisciplinary doctoral training, and conduct research in the area of offshore wind energy generation. Contributions from expert, external authors are also included, and the complete work seeks to bridge the gap between research and a rapidly-evolving industry.

Author: Gary L. Doll
Publisher: Elsevier
ISBN: 0128221747
Category : Technology & Engineering
Languages : en
Pages : 292

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Rolling Bearing Tribology: Tribology and Failure Modes of Rolling Element Bearings discusses these machine elements that are used to accommodate motion on or about shafts in mechanical systems, with ball bearings, cylindrical roller bearings, spherical roller bearings, and tapered roller bearings reviewed. Each bearing type experiences different kinds of motion and forces with their respective raceway, retainers and guiding flanges. The material in this book identifies the tribology of the major bearing types and how that tribology depends upon materials, surfaces and lubrication. In addition, the book describes the best practices to mitigate common failure modes of rolling element bearings. Discusses important tribological implications surrounding the performance and durability of rolling element bearings Describes how the different types of roller bearings work Explores the reasons behind the failure of roller bearings and presents information on how to mitigate those failures

Author: Brian McNiff
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author:
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Category :
Languages : en
Pages : 0

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The most common failure mode in wind turbine gearboxes is axial cracking in intermediate and high-speed-stage bearings, also commonly called white-etching cracks (WECs). Although these types of cracks have been reported for over a decade, the conditions leading to WECs, the process by which this failure culminates, and the reasons for their apparent prevalence in wind turbine gearboxes are all highly debated. This paper summarizes the state of a multipronged research effort to examine the causes of WECs in wind turbine gearbox bearings. Recent efforts have recreated WECs on a benchtop test rig in highly loaded sliding conditions, wherein it was found that the formation of a dark etching microstructure precedes the formation of a crack, and a crack precedes the formation of white-etching microstructure. A cumulative frictional sliding energy criterion has been postulated to predict the presence of WECs. Bearing loads have also been measured and predicted in steady state and transient drivetrain operations in dynamometer testing. In addition, both loads and sliding at full scale will be measured in planned uptower drivetrain testing. If the cumulative frictional sliding energy is the dominant mechanism that causes WECs, understanding the amount of frictional sliding energy that wind turbine bearings are subjected to in typical operations is the next step in the investigation. If highly loaded sliding conditions are found uptower, similar to the examined benchtop levels, appropriate mitigation solutions can be examined, ranging from new bearing coatings and improved lubricants to changes in gearbox designs and turbine operations.

Author: Bella H. Chudnovsky
Publisher: CRC Press
ISBN: 1498754775
Category : Science
Languages : en
Pages : 639

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The revised edition presents, extends, and updates a thorough analysis of the factors that cause and accelerate the aging of conductive and insulating materials of which transmission and distribution electrical apparatus is made. New sections in the second edition summarize the issues of the aging, reliability, and safety of electrical apparatus, as well as supporting equipment in the field of generating renewable energy (solar, wind, tide, and wave power). When exposed to atmospheric corrosive gases and fluids, contaminants, high and low temperatures, vibrations, and other internal and external impacts, these systems deteriorate; eventually the ability of the apparatus to function properly is destroyed. In the modern world of "green energy", the equipment providing clean, electrical energy needs to be properly maintained in order to prevent premature failure. The book’s purpose is to help find the proper ways to slow down the aging of electrical apparatus, improve its performance, and extend the life of power generation, transmission, and distribution equipment.