Failures of Sliding Bearings

2021 ◽  
pp. 435-444
Author(s):  
Harish Hirani
Keyword(s):  
Failure Analysis ◽  
Boundary Lubrication ◽  
Squeeze Film ◽  
Sliding Bearings ◽  
Damage Mechanisms ◽  
Rolling Ball ◽  
Bearing Materials ◽  
Bearing Design ◽  
Wear Damage ◽  
Film Lubrication

Abstract A mechanical part, which supports the moving part, is termed a mechanical bearing and can be classified into rolling (ball or roller) bearings and sliding bearings. This article discusses the failures of sliding bearings. It first describes the geometry of sliding bearings, next provides an overview of bearing materials, and then presents the various lubrication mechanisms: hydrostatic, hydrodynamic, boundary lubrication, elastohydrodynamic, and squeeze-film lubrication. The article describes the effect of debris and contaminant particles in bearings. The steps involved in failure analysis of sliding bearings are also covered. Finally, the article discusses wear-damage mechanisms from the standpoint of bearing design.

Effect of concentration dependence of viscosity on squeeze film lubrication

2020 ◽  
Vol 75 (6) ◽  
pp. 533-542
Author(s):  
Poosan Muthu ◽  
Vanacharla Pujitha
Keyword(s):  
Carrying Capacity ◽  
Iterative Procedure ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Convection Diffusion ◽  
Load Carrying ◽  
Newtonian Viscous Fluid ◽  
Nicolson Scheme ◽  
Human Joint ◽  
Film Lubrication

AbstractThe influence of concentration of solute particles on squeeze film lubrication between two poroelastic surfaces has been analyzed using a mathematical model. Newtonian viscous fluid is considered as a lubricant whose viscosity varies linearly with concentration of suspended solute particles. Convection-diffusion model is proposed to study the concentration of solute particles and is solved using finite difference method of Crank–Nicolson scheme. An iterative procedure is used to get the solution for concentration, pressure and velocity components in film region. It has been observed that load carrying capacity decreases as the concentration of solute particles in the fluid film decreases. Further, the concentration of suspended solute particles decreases as the permeability of the poroelastic plate increases and these results may be useful in understanding the mechanism of human joint.

Effect of surface roughness on couple stress squeeze film lubrication of long porous partial journal bearings

2006 ◽  
Vol 58 (4) ◽  
pp. 176-186 ◽  
Author(s):  
N.M. Bujurke ◽  
N.B. Naduvinamani ◽  
Syeda Tasneem Fathima ◽  
S.S. Benchalli
Keyword(s):  
Surface Roughness ◽  
Couple Stress ◽  
Journal Bearings ◽  
Squeeze Film ◽  
Film Lubrication ◽  
Effect Of Surface

Mechanism of Boundary Lubrication and the Edge Effect

1965 ◽  
Vol 87 (3) ◽  
pp. 735-739 ◽  
Author(s):  
Y. Tamai ◽  
B. G. Rightmire
Keyword(s):  
Thin Film ◽  
Acid Solution ◽  
Palmitic Acid ◽  
Boundary Lubrication ◽  
Frictional Resistance ◽  
Copper Surface ◽  
Bulk Liquid ◽  
Attraction Force ◽  
Thin Film Lubrication ◽  
Film Lubrication

Experimental work was carried out on the boundary lubrication of a copper-copper couple with pure cetane, palmitic acid solution of cetane, and some other organic materials. The purpose was to get information about α and μlube, which appear in the friction equation: μ=αμsolid+(1−α)μlube, by using two different kinds of copper surface, a clean surface, and an oxidized surface. α was found to be small with palmitic acid solution, and the estimated shear strength of palmitic acid was high under the examined condition. α and μlube seemed to be properties which are independent of each other. α is closely related to the attraction force between the lubricant and the substrate, whereas μlube is related to the complexity of molecular structure of the lubricant. A comparison was made of bulk-liquid and thin-film lubrication. μlube was smaller in thin-film lubrication than it was in bulk-liquid lubrication. This suggests that the frictional resistance may be partly contributed by liquid in the edge space around the real contact.

Progressive Failure Analysis of Thermoplastic PE/PE Composites: Labeling of Clustered AE Signals

2013 ◽  
Vol 821-822 ◽  
pp. 1479-1483
Author(s):  
Bi Ling Yang ◽  
Sen Liu ◽  
Xiao Xia He ◽  
Shao Qiong Zheng
Keyword(s):  
Failure Analysis ◽  
Progressive Failure ◽  
Tensile Load ◽  
Matrix Cracking ◽  
Thermoplastic Composites ◽  
Damage Mechanisms ◽  
Progressive Failure Analysis ◽  
Fast Fourier Transform Analysis ◽  
Static Tensile ◽  
Ae Signals

Thermoplastic self-reinforced polyethylene (PE/PE) composites were tested under quasi-static tensile load and the failure processes weremonitored by Acoustic Emission (AE) technique. The AE signals were collected and clustered by Unsupervised Pattern Recognition (UPR) scheme. The initiation and progression of the damage mechanisms in the composites can then be reviewed by the cumulative AE hits of each cluster versus strain curves. But the labeling of each cluster is crucial to the failure analysis. The paper focuses on this correlating between the obtained clusters and their specific damage modes. This was carried out by waveform visualization and Fast Fourier Transform analysis. Pure resin and fiber bundles were tested to assist in the labeling of signal classes in the composites (90°, 0° and [±45°] specimens). Typical waveforms of matrix cracking, fiber-matrix debonding, fiber fracture and fiber pullout were indentified respectively. The evolution process of various damage mechanisms in the composites revealed that the correlating method was effective. An objective and repeatable analytical procedure is established for the investigation of progressive failure mechanisms in the thermoplastic composites.

Numerical investigation of squeeze film lubrication on bioinspired hexagonal patterned surface

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Binbin Su ◽  
Xianghe Zou ◽  
Lirong Huang
Keyword(s):  
Flow Rate ◽  
Carrying Capacity ◽  
Squeeze Film ◽  
Load Carrying Capacity ◽  
Two Dimensional ◽  
Working Mechanism ◽  
Content Type ◽  
Patterned Surface ◽  
Load Carrying ◽  
Film Lubrication

Purpose This paper aims to investigate the squeeze film lubrication properties of hexagonal patterned surface inspired by the epidermis structure of tree frog’s toe pad and numerically explore the working mechanism of hexagonal micropillar during the acquisition process of high adhesive and friction for wet contacts. Design/methodology/approach A two-dimensional elastohydrodynamic numerical model is employed for the squeezing contacts. The pressure distribution, load carrying capacity and liquid flow rate of the squeeze film are obtained through a simultaneous solution of the two-dimensional Reynolds equation and elasticity deformation equations. Findings Higher pressure is found to be longitudinally distributed across individual hexagonal pillar, with pressure peak emerging at the center of hexagonal pillar. Expanding the area density and shrinking the channel depth or initial film thickness will improve the magnitude of squeezing pressure. Relatively lower pressure is generated inside interconnected channels, which reduces the load carrying capacity of the squeeze film. Meanwhile, the introduction of microchannel is revealed to downscale the total mass flow rate of squeezing contacts. Originality/value This paper provides a good proof for the working mechanism of surface microstructures during the acquisition process of high adhesive and friction for wet contacts.

scholarly journals Effect of Pressure Dependent Viscosity on Couple Stress Squeeze Film Lubrication between Rough Parallel Plates

2015 ◽  
Vol 10 (1) ◽  
pp. 76-83 ◽  
Author(s):  
Neminath Bujappa Naduvinamani ◽  
Siddangouda Apparao ◽  
Hiremath Ayyappa Gundayya ◽  
Shivraj Nagshetty Biradar
Keyword(s):  
Couple Stress ◽  
Squeeze Film ◽  
Parallel Plates ◽  
Effect Of Pressure ◽  
Pressure Dependent Viscosity ◽  
Dependent Viscosity ◽  
Film Lubrication
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