Download or read book The Effect of Surface Roughness on the Micro elastohydrodynamic Lubrication and Scuffing Performance of Aerospace Gear Tooth Contracts written by M.J. Patching and published by . This book was released on 1994 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Surface Roughness on the Micro elastohydrodynamic Lubriation and Scuffing Performance of Aerospace Gear Tooth Contacts written by Michael John Patching and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elastohydrodynamics 96 written by C. Taylor and published by Elsevier. This book was released on 1997-07-22 with total page 773 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume represents the latest issue of a collection of Proceedings each dealing with a different topic in Tribology. This volume contains the Proceedings from the 23rd Leeds-Lyon Symposium which addressed the topic of Elastohydrodynamics and was attended by many international experts in the field.The Keynote Address was presented by Professor Stathis Ioannides on the subject of "Tribology in Rolling Element Bearings" and was followed by fifteen other sessions covering a wide variety of general areas from "Experimental" to "Lubricant Properties". In addition, nine other invited technical papers were presented to support the sessions.
Download or read book Lubrication at the Frontier The Role of the Interface and Surface Layers in the Thin Film and Boundary Regime written by M. Priest and published by Elsevier. This book was released on 1999-07-01 with total page 911 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 25th Leeds-Lyon Symposium on Tribology was held at the Institut des Sciences Appliquées de Lyon, from 8-11th September, 1998. Its central theme was, "Lubrication at the frontier: the role of the interface and surface layers in the thin film and boundary regime". This topic was chosen because it represents an important evolution of the research field.The Symposium opened with a keynote address entitled "Role of surface-anchored polymer chains in polymer friction" which described the processes taking place at the interface between "solid" and "liquid". The keynote address was followed by two invited lectures. Firstly, "Fuel efficient engine oils, additive interactions, boundary friction and wear" presented the industrial point of view on lubricant formulation and engine testing and its evolution. The second lecture was entitled "For establishment of a new EHL theory" and stressed the need to extend the current EHL theory.Beginning in 1974, The Leeds-Lyon Symposia have now covered a wide range of topics. The essential aim each year is to select a topic of current interest to tribologists and to contribute to further the advance of knowledge in selected fields.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 1252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ASME Technical Papers written by and published by . This book was released on 1999 with total page 450 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of Scuffing Performance of a Helical Gear Pair Subjected to Different Lubrication Methods written by Rohit Matthew Abraham and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Lubrication systems used in gear trains are intended to serve two distinct purposes: (i) provide the quantities of oil to gear mesh contact interfaces to allow formation of a healthy elastohydrodynamic fluid film and (ii) help remove heat generated at gear mesh contact interfaces. Failure of the lubrication system in either of these tasks often results in a temperature induced contact failure, called scuffing. This study investigates the effectiveness of various lubrication methods in preventing scuffing. A new high-speed gear test set-up is developed specifically for investigating the scuffing performance of high-speed, high-load helical gears operating at realistic oil temperature conditions. The objective of this study is to experimentally characterize the scuffing performance of the helical gears as a function of various lubrication methods and parameters defining each method. Sets of scuffing experiments are performed using the test methodology developed and lubrication methods that successfully prevented scuffing of the gears are identified. The test matrix includes two different automotive drivetrain lubricants and different lubrication methods of forced (jet) lubrication, dip lubrication and mist lubrication. The test specimens consist of gears having three surface finishes, (i) ground-honed gears which were identified as the baseline, (ii) super-finished gears and (iii) phosphate coated gears. The effects of parameters such as jet flow rate, jet velocity and impingement depth on scuffing are investigated and tabulated using the results from the jet lubricated tests. The impact of gear micro-geometry and edge-loading effects on scuffing initiation are also investigated.
Download or read book Assessment of Lubricated Contacts Mechanisms of Scuffing and Scoring written by and published by . This book was released on 1983 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Tribology written by and published by . This book was released on 2000 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Surface Roughness Effects in Hydrodynamic and Mixed Lubrication written by Steve M. Rohde and published by . This book was released on 1980 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 1995 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theses on any subject submitted by the academic libraries in the UK and Ireland.
Download or read book Paper written by and published by . This book was released on 1999 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Influence of Surface Treatments on Micropitting and Scuffing written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final report of the contract issued on 1 May 2001; this contract was a follow-on of contracts N68171-98-M-5294 and N68171-99-M-6457. Hence this report is based on an update of actions described in previous interim reports either covered by contracts N68171-98-M-5294, N68171-99-M-6457 or by the current contract. The focus of the current contract was on the scuffing performance of an ultra hard thin coating optimized for gearing applications. The original engineering background to this work was the need to understand the behavior and failure of gear tooth contacts used in demanding aerospace applications such as aircraft engine and helicopter gearboxes. Scuffing tests, designed to measure the performance of a particular combination of lubricant and gear steel, are usually impractical on lull-scale machinery, while tests using smaller gears are expensive. Furthermore, it is difficult to measure quantities of interest for research purposes, such as friction and bulk temperature. Fundamental research investigations of scuffing under controlled conditions are therefore more conveniently carried out through the use of disc machines.
Download or read book Effect of Longitudinal Surface Finish on Elastohydrodynamic Lubrication written by Thomas A. Dow and published by . This book was released on 1975 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 An Experimental Study on the Scuffing Performance of High power Spur Gears at Elevated Oil Temperatures written by James Walter Brenneman and published by . This book was released on 2013 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this study, a number of spur gear tests were performed under high-power and high-temperature conditions representative of certain aerospace gearing applications. As the first type of tests, long cycle tests of 100 million cycles were performed at set operating speed, load, and temperature conditions. The second type of tests, load-staged scuffing tests, implemented an incrementally increased torque schedule under constant speed and oil temperature conditions. Two different gear tooth surfaces were considered in these tests: hard ground surfaces representative of rough, as machined gear surfaces and chemically polished gear surfaces that were an order of magnitude smoother than the ground surfaces. The primary failure mode of concern was scuffing of the contact surfaces due to temperature build up. The impact of surface roughness amplitudes, contact stress, and oil inlet temperature on scuffing failures were investigated. Effects of ramp up procedures for the speed and torque, as well as the introduction of a break-in test stage were also investigated to show that they are critical to the scuffing performance of gears.
