Tilting-Pad Bearings—The Contact Flexibility of the Pivot

The modeling of tilting-pad journal and thrust bearings presents a level of complexity beyond that of bearings with a fixed-arc geometry, particularly with regard to their dynamic influences. With tilting-pad bearings, the theory surrounding their fluid film must be complemented with the representat...

Full description

Bibliographic Details
Main Author: Laurence F. Wagner
Format: Article
Language:English
Published: MDPI AG 2023-04-01
Series:Lubricants
Subjects:
Online Access:https://www.mdpi.com/2075-4442/11/5/189
_version_ 1827740950928031744
author Laurence F. Wagner
author_facet Laurence F. Wagner
author_sort Laurence F. Wagner
collection DOAJ
description The modeling of tilting-pad journal and thrust bearings presents a level of complexity beyond that of bearings with a fixed-arc geometry, particularly with regard to their dynamic influences. With tilting-pad bearings, the theory surrounding their fluid film must be complemented with the representative modeling of the pad dynamics. What has been recognized in recent decades is the significance of the pad support, in particular the flexibility of the pivot region of the pad. The typical model for including the stiffness of the pivot is based on the Hertzian contact theory. Some researchers have noted that the Hertzian theory does not permit sufficient flexibility in the pivot region. It has been suggested that the contact mechanics at the pivot would be better represented as a pairing of rough surfaces. The modeling used here is based on a statistical asperity micro-contact theory for rough surface line contact that has been extended to include contact stiffness. This model has been applied to the determination of the effective dynamic properties of tilting-pad bearings. The results show that pivot stiffness can be as low as one third of the stiffness determined by the Hertzian theory. A comparison to published experimental results confirms the significance of the rough surface modeling, particularly for the line contacts associated with rocker-back tilting pads.
first_indexed 2024-03-11T03:33:40Z
format Article
id doaj.art-9861e85c931042ea9f3b92347fbb07a6
institution Directory Open Access Journal
issn 2075-4442
language English
last_indexed 2024-03-11T03:33:40Z
publishDate 2023-04-01
publisher MDPI AG
record_format Article
series Lubricants
spelling doaj.art-9861e85c931042ea9f3b92347fbb07a62023-11-18T02:10:29ZengMDPI AGLubricants2075-44422023-04-0111518910.3390/lubricants11050189Tilting-Pad Bearings—The Contact Flexibility of the PivotLaurence F. Wagner0Rotor Bearing Solutions International LLC., 5211 Mountainview Rd., Winston Salem, NC 27104, USAThe modeling of tilting-pad journal and thrust bearings presents a level of complexity beyond that of bearings with a fixed-arc geometry, particularly with regard to their dynamic influences. With tilting-pad bearings, the theory surrounding their fluid film must be complemented with the representative modeling of the pad dynamics. What has been recognized in recent decades is the significance of the pad support, in particular the flexibility of the pivot region of the pad. The typical model for including the stiffness of the pivot is based on the Hertzian contact theory. Some researchers have noted that the Hertzian theory does not permit sufficient flexibility in the pivot region. It has been suggested that the contact mechanics at the pivot would be better represented as a pairing of rough surfaces. The modeling used here is based on a statistical asperity micro-contact theory for rough surface line contact that has been extended to include contact stiffness. This model has been applied to the determination of the effective dynamic properties of tilting-pad bearings. The results show that pivot stiffness can be as low as one third of the stiffness determined by the Hertzian theory. A comparison to published experimental results confirms the significance of the rough surface modeling, particularly for the line contacts associated with rocker-back tilting pads.https://www.mdpi.com/2075-4442/11/5/189bearingstilting-paddynamiccoefficientsstiffnessdamping
spellingShingle Laurence F. Wagner
Tilting-Pad Bearings—The Contact Flexibility of the Pivot
Lubricants
bearings
tilting-pad
dynamic
coefficients
stiffness
damping
title Tilting-Pad Bearings—The Contact Flexibility of the Pivot
title_full Tilting-Pad Bearings—The Contact Flexibility of the Pivot
title_fullStr Tilting-Pad Bearings—The Contact Flexibility of the Pivot
title_full_unstemmed Tilting-Pad Bearings—The Contact Flexibility of the Pivot
title_short Tilting-Pad Bearings—The Contact Flexibility of the Pivot
title_sort tilting pad bearings the contact flexibility of the pivot
topic bearings
tilting-pad
dynamic
coefficients
stiffness
damping
url https://www.mdpi.com/2075-4442/11/5/189
work_keys_str_mv AT laurencefwagner tiltingpadbearingsthecontactflexibilityofthepivot