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EBookClubs

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Book The Role of Thermoelastic Effects in the Scuffing Failure of Rolling Sliding EHD Contacts

Download or read book The Role of Thermoelastic Effects in the Scuffing Failure of Rolling Sliding EHD Contacts written by R. R. Johnson and published by . This book was released on 1988 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-dimensional numerical solution of the thermal Reynolds', elasticity, and energy equations resulted in predictions of the flow velocities and temperatures within the lubricant film between a crown roller and a rotating shaft. The results showed a good agreement with previously measured experimental data on the surface temperatures in an EHD contact and on the resulting frictional torques for both rolling and sliding. A pressure and temperature dependent viscosity was assumed for the synthetic paraffinic hydrocarbon used in the experiments. This model allowed an evaluation of the relative importance of the generation, viscous dissipation, and compression terms in the energy equation at different stations along the mid-film line of contact. Based on the insight about the relative importance of terms as found in the numerical simulation, convenient expressions were developed for an approximate method of predicting the mid-film temperature and sliding friction force. The influence of thermal expansion of the contact between a crowned surface in sliding contact with a rotating cylindrical surface was included in a model of thermoelastic instability to predict the onset of scuffing failure. The simplified approach assumed a heat balance between the generation from friction and the heat conducted into the cylinders. (RH).

Book An Experimental Study of Thermoelastic Effects in Scuffing Failure of Sliding EHD Contacts

Download or read book An Experimental Study of Thermoelastic Effects in Scuffing Failure of Sliding EHD Contacts written by Jennifer L. Rhatigan and published by . This book was released on 1987 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Thermal and Thermoelastic Effects in Rolling Sliding Contacts

Download or read book Thermal and Thermoelastic Effects in Rolling Sliding Contacts written by T. A. Dow and published by . This book was released on 1984 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a theoretical and experimental study of thermal and thermomechanical effects on frictionally and electrically heated rolling/sliding surfaces. A 2-D thermal analysis is used to predict the temperature distribution through the thickness of the lubricant film in an elastohydrodynamic (EHD) contact. The relative magnitude of shear and compressive heating as well as the losses due to conduction and convection are compared for pure rolling and slip conditions. Originator-supplied key words include: Tribology, Elastohydrodynamic lubrication, Electrical brush, Wear, Thermal effects, Thermomechanical effects, Lubricant rheology, and High current density monolithic electrical brushes.

Book Scientific and Technical Aerospace Reports

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Thermal and Thermomechanical Effects in Rolling Sliding Contacts

Download or read book Thermal and Thermomechanical Effects in Rolling Sliding Contacts written by T. A. Dow and published by . This book was released on 1981 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The program involved analysis and experimentation relating to thermal effects in two important systems: elastohydrodynamically (EHD) lubricated bearings or gears, and high-current-density electrical brushes. A thermodynamic heat balance has been applied to an EHD contact utilizing experimental values for surface pressure and temperature distributions. The results showed that the magnitude of compressive and shear heating in the lubricant were higher than that due to convection to the fluid. Experimental measurements of axial film thickness profiles for rolling/sliding disks were made using an X-ray shadow technique. The objective was to determine if the profile under load will vary due to nonuniform heating and thermal expansion at the disk contact leading to scuffing failure. No significant changes in profile were measured, but a limited range of experimental conditions were studied. A high-current-density electrical slip ring apparatus was constructed and used to study the effect of material properties on the contact between the stationary brush and the copper slip ring. The results showed that above a particular threshold speed, the brushes exhibited a sparking phenomenon which consisted of periodic motion of a cluster of small sparks at the brush/slip ring interface.

Book Government Reports Announcements Index

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1989 with total page 1098 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Lubricants and Lubrication

Download or read book Lubricants and Lubrication written by G. Dalmaz and published by Elsevier. This book was released on 1995-10-05 with total page 709 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings review progress in the development of lubricants and in the understanding of the phenomena of lubrication. The contents include papers on the impact of automotive technology and environmental factors upon lubricant requirements, elasto-hydrodynamic lubrication, boundary lubrication, machine elements, bio-tribology, metal forming, rheology, lubricated wear and very thin film (nano metre) lubrication. Presented by leading scientists from 22 different countries, these proceedings provide an up-to-date review of developments in this field.

Book Thermomechanical Effects in Wear

Download or read book Thermomechanical Effects in Wear written by and published by . This book was released on 1982 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Metals Abstracts

Download or read book Metals Abstracts written by and published by . This book was released on 1989 with total page 1266 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Journal of Tribology

Download or read book Journal of Tribology written by and published by . This book was released on 2001 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Journal of Lubrication Technology

Download or read book Journal of Lubrication Technology written by and published by . This book was released on 1979 with total page 1178 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book A Methodology to Establish Scuffing Limits for Lubricated Point Contacts Subject to Sliding

Download or read book A Methodology to Establish Scuffing Limits for Lubricated Point Contacts Subject to Sliding written by Michael James Handschuh and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Scuffing, also known as scoring, is a heat-induced failure mode of lubricated contacts. Any lubricated contact that is subject to high pressures and high sliding velocities is especially susceptible to scuffing failures if it generates more heat than the amount that can be removed from it by the lubricant. Most of the gear contacts in high-speed aerospace gearboxes as well as electric vehicle transmissions are prone to stuffing. In this study, the scuffing performance of such contacts in combined rolling and sliding are studied in an effort to develop a hybrid methodology for establishing scuffing limits. This hybrid methodology relies on two essential components: (i) tightly controlled scuffing experiments where key contact parameters are measured in the onset of scuffing, and (ii) thermal elastohydrodynamic modeling of the same contacts.