Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing

This paper formulated a modified Reynolds equation that can calculate the lubrication characteristics of bearings with high-viscosity surface layers on both bearing surfaces expressed by arbitrary viscosity function. From comparison with the measured effective viscosity of engine oil with metallic d...

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Main Author: Kyosuke Ono
Format: Article
Language:English
Published: Japanese Society of Tribologists 2024-02-01
Series:Tribology Online
Subjects:
Online Access:https://www.jstage.jst.go.jp/article/trol/19/1/19_23/_pdf/-char/en
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author Kyosuke Ono
author_facet Kyosuke Ono
author_sort Kyosuke Ono
collection DOAJ
description This paper formulated a modified Reynolds equation that can calculate the lubrication characteristics of bearings with high-viscosity surface layers on both bearing surfaces expressed by arbitrary viscosity function. From comparison with the measured effective viscosity of engine oil with metallic detergent, the saturated viscosity function was determined, where the effective viscosity saturates to 500 times the bulk viscosity when the gap decreases to the saturated viscosity film thickness 2zc of 100 nm. Then, the lubrication characteristics of micro-tapered pad bearing of 250 µm in length were analyzed. The load capacity was ~70 times the bulk viscosity case when the trailing gap hT decreased to 2zc. Next, the effective viscosity of engine oil with only a viscosity modifier additive can be obtained by using another viscosity function in which the increasing rate in viscosity is maximum on the bearing surface and 2zc is ~60 nm. Using this viscosity function, the bearing characteristics of tapered pad bearing were analyzed. The load capacity was ~13 times the bulk viscosity case when hT was zc. For both the viscosity functions, the load capacity was almost the same if the film thickness of the one-side model is twice as large as that of the two-side model.
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spelling doaj.art-b30b9e0d6dda46a1924cf1fcc44d7aec2024-04-11T09:43:09ZengJapanese Society of TribologistsTribology Online1881-21982024-02-01191233210.2474/trol.19.23trolModified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad BearingKyosuke Ono0Tokyo Institute of TechnologyThis paper formulated a modified Reynolds equation that can calculate the lubrication characteristics of bearings with high-viscosity surface layers on both bearing surfaces expressed by arbitrary viscosity function. From comparison with the measured effective viscosity of engine oil with metallic detergent, the saturated viscosity function was determined, where the effective viscosity saturates to 500 times the bulk viscosity when the gap decreases to the saturated viscosity film thickness 2zc of 100 nm. Then, the lubrication characteristics of micro-tapered pad bearing of 250 µm in length were analyzed. The load capacity was ~70 times the bulk viscosity case when the trailing gap hT decreased to 2zc. Next, the effective viscosity of engine oil with only a viscosity modifier additive can be obtained by using another viscosity function in which the increasing rate in viscosity is maximum on the bearing surface and 2zc is ~60 nm. Using this viscosity function, the bearing characteristics of tapered pad bearing were analyzed. The load capacity was ~13 times the bulk viscosity case when hT was zc. For both the viscosity functions, the load capacity was almost the same if the film thickness of the one-side model is twice as large as that of the two-side model.https://www.jstage.jst.go.jp/article/trol/19/1/19_23/_pdf/-char/enthin film lubricationmodified reynolds equationsaturated viscosity layerengine oiladditivestapered pad bearinglubricant rheologyarbitrary viscosity layeradsorbed lubricant film
spellingShingle Kyosuke Ono
Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing
Tribology Online
thin film lubrication
modified reynolds equation
saturated viscosity layer
engine oil
additives
tapered pad bearing
lubricant rheology
arbitrary viscosity layer
adsorbed lubricant film
title Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing
title_full Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing
title_fullStr Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing
title_full_unstemmed Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing
title_short Modified Reynolds Equation for Thin Film Lubrication with Arbitrarily Enhanced Viscosity Surface Layers and Lubrication Analysis of Micro-Tapered Pad Bearing
title_sort modified reynolds equation for thin film lubrication with arbitrarily enhanced viscosity surface layers and lubrication analysis of micro tapered pad bearing
topic thin film lubrication
modified reynolds equation
saturated viscosity layer
engine oil
additives
tapered pad bearing
lubricant rheology
arbitrary viscosity layer
adsorbed lubricant film
url https://www.jstage.jst.go.jp/article/trol/19/1/19_23/_pdf/-char/en
work_keys_str_mv AT kyosukeono modifiedreynoldsequationforthinfilmlubricationwitharbitrarilyenhancedviscositysurfacelayersandlubricationanalysisofmicrotaperedpadbearing