Author: Jonathan KellerPublisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 41
Book Description
Uptower Investigation of Main and High-speed-shaft Bearing Reliability
Author: Jonathan KellerPublisher:
ISBN:
Category : Bearings (Machinery)
Languages : en
Pages : 41
Book Description
Investigating Main and High-Speed Shaft Bearing Reliability through Uptower Testing
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
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.
High-speed Shaft Bearing Loads Testing and Modeling in the NREL Gearbox Reliability Collaborative :.
Author: Brian McNiffInvestigation of Bearing Axial Cracking: Benchtop and Full-Scale Test Results
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
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.
Long-term Research Challenges in Wind Energy - A Research Agenda by the European Academy of Wind Energy
Author: Gijs van KuikPublisher: Springer
ISBN: 3319469193
Category : Technology & Engineering
Languages : en
Pages : 111
Book Description
This book presents the view of European wind energy experts on the long-term research challenges to be solved in order to develop wind energy beyond the applications of today and tomorrow. By this book, the European Academy of Wind Energy (eawe), representing universities and institutes with a significant wind energy programme in 14 countries, wants to: identify current technological and scientific barriers and to stimulate new creative ideas to overcome these barriers define priorities for future scientific research rethink our scientific view of wind energy stimulate the cooperation among researchers in fundamental and applied sciences towards wind energy research The eawe has discussed these long-term research with an explicit focus on a longer-term perspective, in contrast to research agendas addressing short- to medium-term research activities. In other words, this long-term research agenda is driven by problems and curiosity, addressing basic research and fundamental knowledge in 11 research areas, ranging from physics and design to environmental and societal aspects. Because of the very nature of this initiative, this document does not intend to be permanent or complete. It shows the vision of the experts of the European Academy of Wind Energy, but other views may be possible. The eawe sincerely hopes that it will spur an even more intensive discussion worldwide within the wind energy community.
The Continuing Study of Newspaper Reading
Author: Advertising Research FoundationPublisher:
ISBN:
Category : Advertising
Languages : en
Pages : 646
Book Description
Wind Turbines
Author: Erich HauPublisher: Springer Science & Business Media
ISBN: 3540292845
Category : Technology & Engineering
Languages : en
Pages : 792
Book Description
Wind Turbines addresses all those professionally involved in research, development, manufacture and operation of wind turbines. It provides a cross-disciplinary overview of modern wind turbine technology and an orientation in the associated technical, economic and environmental fields. It is based on the author's experience gained over decades designing wind energy converters with a major industrial manufacturer and, more recently, in technical consulting and in the planning of large wind park installations, with special attention to economics. The second edition accounts for the emerging concerns over increasing numbers of installed wind turbines. In particular, an important new chapter has been added which deals with offshore wind utilisation. All advanced chapters have been extensively revised and in some cases considerably extended
Ice
Author: Publisher:
ISBN:
Category : Refrigeration and refrigerating machinery
Languages : en
Pages : 740
Book Description
Scientific American
Author: Heads in Beds
Author: Jacob TomskyPublisher: Anchor
ISBN: 030794834X
Category : Biography & Autobiography
Languages : en
Pages : 322
Book Description
In the tradition of Kitchen Confidential and Waiter Rant, a rollicking, eye-opening, fantastically indiscreet memoir of a life spent (and misspent) in the hotel industry. “Highly amusing."—New York Times Jacob Tomsky never intended to go into the hotel business. As a new college graduate, armed only with a philosophy degree and a singular lack of career direction, he became a valet parker for a large luxury hotel in New Orleans. Yet, rising fast through the ranks, he ended up working in “hospitality” for more than a decade, doing everything from supervising the housekeeping department to manning the front desk at an upscale Manhattan hotel. He’s checked you in, checked you out, separated your white panties from the white bed sheets, parked your car, tasted your room-service meals, cleaned your toilet, denied you a late checkout, given you a wake-up call, eaten M&Ms out of your minibar, laughed at your jokes, and taken your money. In Heads in Beds he pulls back the curtain to expose the crazy and compelling reality of a multi-billion-dollar industry we think we know. Heads in Beds is a funny, authentic, and irreverent chronicle of the highs and lows of hotel life, told by a keenly observant insider who’s seen it all. Prepare to be amused, shocked, and amazed as he spills the unwritten code of the bellhops, the antics that go on in the valet parking garage, the housekeeping department’s dirty little secrets—not to mention the shameless activities of the guests, who are rarely on their best behavior. Prepare to be moved, too, by his candor about what it’s like to toil in a highly demanding service industry at the luxury level, where people expect to get what they pay for (and often a whole lot more). Employees are poorly paid and frequently abused by coworkers and guests alike, and maintaining a semblance of sanity is a daily challenge. Along his journey Tomsky also reveals the secrets of the industry, offering easy ways to get what you need from your hotel without any hassle. This book (and a timely proffered twenty-dollar bill) will help you score late checkouts and upgrades, get free stuff galore, and make that pay-per-view charge magically disappear. Thanks to him you’ll know how to get the very best service from any business that makes its money from putting heads in beds. Or, at the very least, you will keep the bellmen from taking your luggage into the camera-free back office and bashing it against the wall repeatedly.