Density Variation Effects in Stepped-Thrust Bearings

1959 ◽  
Vol 26 (3) ◽  
pp. 337-340
Author(s):  
C. F. Kettleborough
Keyword(s):  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Density Variation ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Load Carrying ◽  
The Coefficient Of Friction

Abstract The problem of the stepped-thrust bearing is considered but, whereas normally volumetric continuity is assumed, the equations are solved assuming mass continuity; i.e., the variation of density is also considered as well as the effect of the stepped discontinuity on the load-carrying capacity and the coefficient of friction. Computed theoretical curves illustrate the importance of the density on the operation of this bearing and, in part, explain results already published.

scholarly journals Application of topological optimisation methodology to hydrodynamic thrust bearings

2020 ◽  
pp. 135065012097259
Author(s):  
Kalle Kalliorinne ◽  
Roland Larsson ◽  
Andreas Almqvist
Keyword(s):  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Friction Torque ◽  
Shape Optimisation ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Aspect Ratios ◽  
Load Carrying ◽  
The Coefficient Of Friction ◽  
Moving Asymptotes

The bearing geometry has a big impact on the performance of a hydrodynamic thrust bearing. For this reason, shape optimisation of the bearing surface has been carried out for some time, with Lord Rayleigh’s early publication dated back to 1918. There are several recent results e.g. optimal bearing geometries that maximise the load carrying capacity for hydrodynamic thrust bearings. Currently, many engineers are making an effort to include sustainability in their work, which increases the need for bearings with lower friction and higher load carrying capacity. Improving these two qualities will result in lower energy consumption and increase the lifetime of applications, which are outcomes that will contribute to a sustainable future. For this reason, there is a need to find geometries that have performance characteristics of as low coefficient of friction torque as possible. In this work, the topological optimisation method of moving asymptotes is employed to optimise bearing geometries with the objective of minimising the coefficient of friction torque. The results are both optimised bearing geometries that minimise the coefficient of friction torque and bearing geometries that maximise the load carrying capacity. The bearing geometries are of comparable aspect ratios to the ones uses in recent publications. The present article also covers minimisation of friction torque on ring bearing geometries, also known as thrust washers. The results are thrust washers with periodical geometries, where the number of periodical segments has a high impact on the geometrical outcome.

The effect of V-shape protruded and dimple textured on the load-carrying capacity and coefficient of friction of hydrodynamic journal bearing: A comparative numerical study

2020 ◽  
pp. 135065012093500
Author(s):  
Sanjay Sharma ◽  
Aniket Sharma ◽  
Gourav Jamwal ◽  
Rajeev Kumar Awasthi
Keyword(s):  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Performance Enhancement ◽  
Numerical Study ◽  
Geometrical Parameters ◽  
Load Carrying Capacity ◽  
Enhancement Ratio ◽  
Load Carrying ◽  
The Coefficient Of Friction ◽  
Computing Performance

The present comparative numerical study is between V-shape protruded, dimple textured, and untextured bearing. The performance parameters in terms of the load-carrying capacity and coefficient of friction are computed by solving governing Reynold’s equation of the lubricant fluid flow. The governing equation is solved by the finite element method by assuming that the fluid is Newtonian and isoviscous in nature. The effect of eccentricity ratios, texture distribution, texture heights, and texture depths are considered for the analysis in both textured bearings. From simulated results, the load-carrying capacity and coefficient of friction is found to be maximum for protruded textured bearing in full textured region and first half-textured region respectively as compared to untextured bearings. Finally, optimal operating and geometrical parameters of textured bearing is obtained by computing performance enhancement ratio, which is the ratio of the load-carrying capacity to the coefficient of friction. The maximum value of the performance enhancement ratio is found for protruded and dimple textured bearing in full texturing and second half-region corresponding to the eccentricity ratio of 0.8 and 0.6 respectively at texture height and depth of 0.4.

Performance investigation of micro-pocketed textured pad thrust bearing

2018 ◽  
Vol 70 (8) ◽  
pp. 1388-1395 ◽  
Author(s):  
Shipra Aggarwal ◽  
R.K. Pandey
Keyword(s):  
Coefficient Of Friction ◽  
Cross Sections ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Load Carrying Capacity ◽  
Temperature Relation ◽  
Cross Sectional ◽  
Content Type ◽  
Load Carrying ◽  
Coupled Solution

Purpose The purpose of this paper is to conceive a new surface texture incorporating a tiny shape among the micro-pockets (with circular, rectangular, trapezoidal and triangular cross-sections) and dimples (cylindrical, hemispherical and ellipsoidal) for exploring to enhance the maximum possible performance behaviors of sector shape pad thrust bearing. Design/methodology/approach Numerical simulation of hydrodynamically lubricated sector shape textured pad thrust bearing has been presented incorporating thermal and cavitation effects. The coupled solution of governing equations (Reynolds equation, film thickness expression, viscosity–temperature relation, energy equation and Laplace equation) has been achieved using finite difference method and Gauss–Seidel iterative scheme. Findings With new textured pads, higher load-carrying capacity and lower coefficient of friction are obtained in comparison to plain sector shape pad. Texture pattern comprising square cross-sectional pockets yields higher load-carrying capacity and lower coefficient of friction in comparison to other cross-sectional shapes (circular, trapezoidal and triangular) of pockets considered herein. Originality/value This study reports a new texture, which involves micro-pockets of square cross-sectional shapes to improve the performance behavior of sector shape pad thrust bearing. About 75 per cent increase in load carrying capacity and 42 per cent reduction in coefficient of friction have been achieved with pad having new texture in comparison to conventional pad.

The Impact of Linear Deformations on Stationary Hydrostatic Thrust Bearings

2002 ◽  
Vol 124 (4) ◽  
pp. 874-877 ◽  
Author(s):  
Noah D. Manring ◽  
Robert E. Johnson ◽  
Harish P. Cherukuri
Keyword(s):  
Pressure Distribution ◽  
Closed Form ◽  
Flow Rate ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Number Flow ◽  
The Impact

In this work, the operating sensitivity of the hydrostatic thrust bearing with respect to pressure-induced deformations will be studied in a stationary setting. Using the classical lubrication equations for low Reynold’s number flow, closed-form expressions are generated for describing the pressure distribution, the flow rate, and the load carrying capacity of the bearing. These expressions are developed to consider deformations of the bearing that result in either concave or convex shapes relative to a flat thrust surface. The impact of both shapes is compared, and the sensitivity of the flow rate and the load carrying capacity of the bearing with respect to the magnitude of the deformation is discussed. In summary, it is shown that all deformations increase the flow rate of the bearing and that concave deformations increase the load carrying capacity while convex deformations decrease this same quantity relative to a non-deformed bearing condition.

The Dual Action Gas Thrust Bearing—A New High Load Bearing Concept

1977 ◽  
Vol 99 (1) ◽  
pp. 89-94
Author(s):  
I. Etsion
Keyword(s):  
Numerical Solution ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Load Capacity ◽  
High Load ◽  
Load Carrying Capacity ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Dual Action ◽  
Hydrodynamic Effects

The principle of utilizing hydrodynamic effects in diverging films for improving load capacity in gas thrust bearings is discussed. A new concept of dual action bearing based on that principle is described and analyzed. The potential of the new bearing is demonstrated both analytically for an infinitely long slider and by numerical solution for a flat sector shaped thrust bearing. It is shown that the dual action bearing can extend substantially the range of load carrying capacity in gas lubricated thrust bearings and improve their efficiency.

The Thermally Boosted Oil Lubricated Sliding Thrust Bearing

1974 ◽  
Vol 96 (3) ◽  
pp. 322-328 ◽  
Author(s):  
C. M. Rodkiewicz ◽  
J. C. Hinds ◽  
C. Dayson
Keyword(s):  
Boundary Conditions ◽  
Carrying Capacity ◽  
Thrust Bearing ◽  
Load Carrying Capacity ◽  
Slider Bearing ◽  
Governing Equations ◽  
Temperature Ratio ◽  
Thrust Bearings ◽  
Temperature Boundary ◽  
Load Carrying

The effect of varying the ratio of slider to pad temperature boundary conditions and the influence of varying inlet to outlet ratio of a plane infinitely wide slider bearing is examined. The lubricant is assumed to be incompressible and the variation of viscosity with temperature is taken into account. The nondimensionalized governing equations, transformed in terms of the stream function, are solved numerically. The results show that maintaining a lower slider temperature to pad temperature ratio causes an increase in the load carrying capacity of the bearing. A means of which advantage could be taken of this effect in the design of thrust bearings is suggested.

scholarly journals Antifriction and Antiwear Effect of Lamellar ZrS2 Nanobelts as Lubricant Additives

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 329 ◽  
Author(s):  
Wei Tang ◽  
Chuang Yu ◽  
Shaogang Zhang ◽  
Songyong Liu ◽  
Xingcai Wu ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Carrying Capacity ◽  
Friction And Wear ◽  
Normal Load ◽  
Lubricant Additives ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
The Coefficient Of Friction ◽  
Wear Tests ◽  
Friction And Wear Tests

In this study, the tribological behavior of lamellar ZrS2 nanobelts as lubricant additives was investigated under different concentrations, normal load, velocity, and temperature. The friction and wear tests were performed using a tribometer and with a reciprocating motion. The results indicate that the lamellar ZrS2 nanobelt additives can effectively reduce the coefficient of friction and running-in time during the running-in period. With the addition of ZrS2, the wear volumes decrease significantly. The wear is mostly influenced by the tribological performance throughout the running-in period. The lower the running-in time and coefficient of friction are during the running-in period, the less amount of wear is shown. ZrS2 can significantly increase the load-carrying capacity of oil. The 1.0 wt% concentration of ZrS2 yields the best antifriction effect, antiwear performance, and load-carrying capacity. The ZrS2 additives can increase the working temperature of the oil. The friction-reducing and antiwear mechanisms of lamellar ZrS2 were discussed.

Paper 16: Tilting Pad Thrust Bearings: Rapid Design Aids

1969 ◽  
Vol 184 (12) ◽  
pp. 120-138 ◽  
Author(s):  
F. A. Martin
Keyword(s):  
Carrying Capacity ◽  
Thrust Bearing ◽  
Total Power ◽  
Load Carrying Capacity ◽  
Specific Load ◽  
Thrust Bearings ◽  
Size Number ◽  
Tilting Pad ◽  
Load Carrying ◽  
Chart Design

Two slide chart design aids are developed for tilting pad thrust bearings in order ( a) to give guidance on load-carrying capacity, considering such limits as allowable oil film thickness and maximum pad temperature, and ( b) to enable the designer to estimate directly the total power loss in double thrust bearing assemblies. These slide charts (each consisting of two sheets) enable variables such as pad size, number of pads, oil specification, specific load, and collar speed to be considered individually. Thus the designer has a tool from which he can obtain a ‘feel’ for bearing performance and see at a glance the interplay between all the variables.

Running-in effect on the load-carrying capacity of a water-lubricated SiC thrust bearing

2005 ◽  
Vol 219 (2) ◽  
pp. 117-124 ◽  
Author(s):  
X Wang ◽  
K Kato ◽  
K Adachi
Keyword(s):  
Carrying Capacity ◽  
Thrust Bearing ◽  
Area Ratio ◽  
Load Carrying Capacity ◽  
Low Friction ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Pore Area ◽  
Type Contact ◽  
Contact Surfaces

It is known the friction of self-mated SiC in water strongly depends on the roughness of their contact surfaces, and a proper running-in process is the way to obtain low friction by smoothing the contact surfaces of SiC with tribochemical wear. In this paper, the running-in process of surface-contacted SiC (thrust-bearing-type contact) in water is studied experimentally. It is found the maximum running-in load has a large influence on the load-carrying capacity, which is measured as the critical load for the transition from hydrodynamic to mixed lubrication in this research. A multi-step loading running-in method is proposed to increase the load-carrying capacity of SiC thrust bearings working in water. Finally, the running-in process of a laser textured SiC surface is studied, the effect of the pore area ratio on the roughness of the run-in surface is reported, and the mechanism of the effect of micropores is discussed.

Computational Fluid Dynamics Thermohydrodynamic Analysis of Three-Dimensional Sector-Pad Thrust Bearings With Rectangular Dimples

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
C. I. Papadopoulos ◽  
L. Kaiktsis ◽  
M. Fillon
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Carrying Capacity ◽  
Thermal Effects ◽  
Operating Conditions ◽  
Load Carrying Capacity ◽  
Performance Indices ◽  
Thrust Bearings ◽  
Load Carrying ◽  
Texture Design

The paper presents a detailed computational study of flow patterns and performance indices in a dimpled parallel thrust bearing. The bearing consists of eight pads; the stator surface of each pad is partially textured with rectangular dimples, aiming at maximizing the load carrying capacity. The bearing tribological performance is characterized by means of computational fluid dynamics (CFD) simulations, based on the numerical solution of the Navier–Stokes and energy equations for incompressible flow. Realistic boundary conditions are implemented. The effects of operating conditions and texture design are studied for the case of isothermal flow. First, for a reference texture pattern, the effects of varying operating conditions, in particular minimum film thickness (thrust load), rotational speed and feeding oil pressure are investigated. Next, the effects of varying texture geometry characteristics, in particular texture zone circumferential/radial extent, dimple depth, and texture density on the bearing performance indices (load carrying capacity, friction torque, and friction coefficient) are studied, for a representative operating point. For the reference texture design, the effects of varying operating conditions are further investigated, by also taking into account thermal effects. In particular, adiabatic conditions and conjugate heat transfer at the bearing pad are considered. The results of the present study indicate that parallel thrust bearings textured by proper rectangular dimples are characterized by substantial load carrying capacity levels. Thermal effects may significantly reduce load capacity, especially in the range of high speeds and high loads. Based on the present results, favorable texture designs can be assessed.

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