Download or read book Thermal Elastohydrodynamic Lubrication of Spur Gears written by K. L. Wang and published by . This book was released on 1980 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Elastohydrodynamic Lubrication of Spur Gears written by Kuan-Lan Wang and published by . This book was released on 1976 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Elastohydrodynamic Lubrication of Spur Gears written by K. L. Wang and published by . This book was released on 1980 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elasto Hydrodynamic Lubrication written by D. Dowson and published by Elsevier. This book was released on 2014-07-18 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elasto-Hydrodynamic Lubrication deals with the mechanism of elasto-hydrodynamic lubrication, that is, the lubrication regime in operation over the small areas where machine components are in nominal point or line contact. The lubrication of rigid contacts is discussed, along with the effects of high pressure on the lubricant and bounding solids. The governing equations for the solution of elasto-hydrodynamic problems are presented. Comprised of 13 chapters, this volume begins with an overview of elasto-hydrodynamic lubrication and representation of contacts by cylinders, followed by a discussion on equations relevant to lubrication, including the Reynolds equation. The reader is then introduced to lubrication of rigid cylinders; the importance of film thickness in highly loaded rigid contacts; the elasticity of solids in contact; and the theory of elasto-hydrodynamic lubrication. Subsequent chapters focus on apparatus and measurements of film thickness and film shape; friction and viscosity; and lubrication of gears and roller bearings. This book will be of interest to tribologists.
Download or read book Nanolubricants written by Jean Michel Martin and published by John Wiley & Sons. This book was released on 2008-04-30 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technology involved in lubrication by nanoparticles is a rapidly developing scientific area and one that has been watched with interest for the past ten years. Nanolubrication offers a solution to many problems associated with traditional lubricants that contain sulphur and phosphorus; and though for some time the production of nanoparticles was restricted by the technologies available, today synthesis methods have been improved to such a level that it is possible to produce large quantities relatively cheaply and efficiently. Nanolubricants develops a new concept of lubrication, based on these nanoparticles, and along with the authors’ own research it synthesises the information available on the topic of nanolubrication from existing literature and presents it in a concise form. Describes the many advantages and potential applications of nanotechnology in the tribological field. Offers a full review of the state-of-the-art as well as much original research that is yet unpublished. Includes sections on boundary lubrication by colloïdal systems, nanolubricants made of metal dichalcogenides, carbon-based nanolubricants, overbased detergent salts, nanolubricants made of metals and boron-based solid nanolubricants and lubrication additives. Authored by highly regarded experts in the field with contributions from leading international academics. Nanolubricants will appeal to postgraduate students, academics and researchers in mechanical engineering, chemical engineering and materials science. It should also be of interest to practising engineers with petroleum companies and mechanical manufacturers.
Download or read book Thermal Elastic hydrodynamic Lubrication by Non Newtonian Fluids with Rough Surfaces written by Jian M. Wang and published by . This book was released on 1995 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1989 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of a Class of Surface Defects on the High speed Scuffing Performance of Spur Gears written by Gunther Shepard Beall and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gear teeth experience contact conditions that vary continuously as they pass through the meshing zone. Thus, not only the sizes but also the positions of surface defects become critical to their scuffing survivability. High-speed gearbox cost and reliability can be improved by quantifying these features and determining their impact on scuffing performance. Pursuant to this, representative defects in the form of scratches are applied in two batches to the contacting surfaces of high-quality spur gear specimens. These, along with an undamaged baseline gear pair, are then tested through a staged scuffing matrix incrementally increasing the operating load, speed, and lubricant temperature. Metrological procedures developed to quantify scratch parameters and track surface damage are used initially and throughout testing to document evolvement of the surfaces. It is concluded that (i) larger scratches generally decrease scuffing performance, (ii) the location of scratches is critical to scuffing performance; scuffing was never observed in areas where sliding velocities were low, (iii) increased wear and heat generation are observed on defects in high-sliding regions, and (iv) wear and tribo-film formation improve the scuffing performance of scratched gears. In addition, thermal elastohydrodynamic lubrication simulations are performed to confirm that increasing scratch width and surface sliding velocities have the most influence on increasing the lubricant flash temperatures.
Download or read book Elasto hydrodynamic Lubrication written by D. Dowson and published by . This book was released on 1966 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Tech Briefs written by and published by . This book was released on 1982 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Thermal Elastohydrodynamic Lubrication in Rolling sliding Contact written by Farshid Sadeghi and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Element Modeling of Elastohydrodynamic Lubrication Problems written by Wassim Habchi and published by John Wiley & Sons. This book was released on 2018-03-13 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covers the latest developments in modeling elastohydrodynamic lubrication (EHL) problems using the finite element method (FEM) This comprehensive guide introduces readers to a powerful technology being used today in the modeling of elastohydrodynamic lubrication (EHL) problems. It provides a general framework based on the finite element method (FEM) for dealing with multi-physical problems of complex nature (such as the EHL problem) and is accompanied by a website hosting a user-friendly FEM software for the treatment of EHL problems, based on the methodology described in the book. Finite Element Modeling of Elastohydrodynamic Lubrication Problems begins with an introduction to both the EHL and FEM fields. It then covers Standard FEM modeling of EHL problems, before going over more advanced techniques that employ model order reduction to allow significant savings in computational overhead. Finally, the book looks at applications that show how the developed modeling framework could be used to accurately predict the performance of EHL contacts in terms of lubricant film thickness, pressure build-up and friction coefficients under different configurations. Finite Element Modeling of Elastohydrodynamic Lubrication Problems offers in-depth chapter coverage of Elastohydrodynamic Lubrication and its FEM Modeling, under Isothermal Newtonian and Generalized-Newtonian conditions with the inclusion of Thermal Effects; Standard FEM Modeling; Advanced FEM Modeling, including Model Order Reduction techniques; and Applications, including Pressure, Film Thickness and Friction Predictions, and Coated EHL. This book: Comprehensively covers the latest technology in modeling EHL problems Focuses on the FEM modeling of EHL problems Incorporates advanced techniques based on model order reduction Covers applications of the method to complex EHL problems Accompanied by a website hosting a user-friendly FEM-based EHL software Finite Element Modeling of Elastohydrodynamic Lubrication Problems is an ideal book for researchers and graduate students in the field of Tribology.
Download or read book Effects of Lubrication Starvation on Flash Temperature for Thermal Mixed Elastohydrodynamic Gear Contacts written by Danielle D. Massé and published by . This book was released on 2019 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lubrication is provided to the gear trains in automotive and aerospace transmission systems to prevent mechanical contact through the formation of a full lubricant film, which in turn removes heat generated at the gear contact surfaces. When debris blocks the inlet nozzle, the flow of lubricant is restricted and mechanical components experience lubrication starvation. Under starved lubrication the temperatures of the contact surfaces become elevated which can lead to the formation of a weld between them, a catastrophic failure mode called scuffing. For spur gears, the occurrence of scuffing is due to high sliding in the vicinity of the root or tip, where the shear thinning effect decreases the lubrication film thickness. This lubricant depletion increases the contact pressure and frictional heat flux beyond a critical limit, resulting in weld formation. The weld is immediately torn apart by the continuous relative motion of the components, causing extreme damage to the tooth surfaces. The objective of this study is to characterize the tribological behavior of high sliding gear contacts under starved lubrication. This is achieved through numerical flow simulations which utilize a generalized Reynolds equation with a non-Newtonian flow coefficient, and incorporate the dependence of lubricant viscosity on pressure and temperature. In order to study the effects of lubrication starvation a film fraction parameter is used in the Reynolds equation, removing the need for measured or assumed inlet lubrication geometry. This work presents a parametric study of engineering surface profiles under different operating conditions to show an asymptotic relationship between flash temperature and the severity of the lubrication starvation, supported by an analysis of pressure, film fraction parameter, friction coefficient, and power loss. The results of these investigations justify further numerical and experimental studies of scuffing failure for gear contacts.
Download or read book On the Influence of Surface and Elastohydrodynamic Lubrication Parameters on Pitting Lives of Spur Gears written by Qihang Zeng and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: While surface roughness conditions are widely accepted to impact the contact fatigue performance of gears, there is no consensus on what surface roughness parameters correlate the pitting life of a spur gear pair better. In this study, such correlation between various surface roughness amplitude parameters and the resultant pitting lives is investigated through an extensive experimental study. Batches of spur gear pairs made of the same steel material and heat treatment, but with two surface finish conditions ("Rough" hard-ground surfaces and "Smooth" surfaces finished with a proprietary process) are procured. Three sets of tests are performed with test specimens of different roughness pairings: Rough-Rough, Smooth-Smooth, and Smooth-Rough. Individual stress-life curves are formed for each set and compared to each other. In addition, all relevant roughness data are collected during these tests to determine which of the standard roughness parameters correlates the measure fatigue lives. In addition, an existing EHL model of a spur gear pair is exercised with measured roughness profiles to simulate all the pitting tests to determine individual lubrication and contact conditions associated with each test. Three EHL-based parameters, average gap (AG), load contact ratio (LCR) and area contact ratio (ACR) are chosen to represent the lubrication conditions regarding asperity interactions. The results indicate that AG correlates with surface roughness parameters Rq and Rz well. All three parameters, AG, Rq and Rz correlate well with the resultant pitting lives
Download or read book Analysis of Thermal Elastohydrodynamic Lubrication in Rolling sliding Contacts written by Farshid Sadeghi and published by . This book was released on 1987 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1982 with total page 1124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
