Turbulent Lubrication of Tilting-Pad Thrust Bearings With Thermal and Elastic Deformations

1985 ◽  
Vol 107 (1) ◽  
pp. 82-86 ◽  
Author(s):  
H. Hashimoto ◽  
S. Wada
Keyword(s):  
Friction Torque ◽  
Shaft Speed ◽  
Centrifugal Forces ◽  
Balance Equations ◽  
Elastic Deformations ◽  
Film Pressure ◽  
Thrust Bearings ◽  
Temperature Distributions ◽  
Tilting Pad ◽  
Energy Equations

Pad deformations of sector-shaped, tilting-pad thrust bearings affecting turbulent lubrication are discussed theoretically. Solving the lubrication and energy equations with turbulence and centrifugal forces and the elastic and moment balance equations of a pad simultaneously, film pressure and temperature distributions, thermal and elastic deformations and inclinations of a pad are obtained. Film thicknesses at a pivot under a constant shaft speed become larger due to pad deformations, whereby pad inclinations increase and friction torque coefficients decrease outstandingly. It is important to introduce the effects of pad deformations when analysing performances of such bearings running in the turbulent conditions.

Evaluating Thermal Performance of a PTFE-Faced Tilting Pad Thrust Bearing

2003 ◽  
Vol 125 (2) ◽  
pp. 319-324 ◽  
Author(s):  
Sergei B. Glavatskih
Keyword(s):  
Thrust Bearing ◽  
Friction Torque ◽  
Outer Diameter ◽  
Test Results ◽  
Operating Characteristics ◽  
Thrust Bearings ◽  
Ptfe Composite ◽  
Temperature Distributions ◽  
Tilting Pad ◽  
Bearing Friction

This paper compares and analyses operating characteristics of equalizing tilting pad thrust bearings with babbitt and polytetrafluoroethylene (PTFE) composite facings. Each bearing arrangement included six pads with an outer diameter of 228.6 mm and 60 percent offset. The babbitted bearing was typical of design in general use. A PTFE composite was applied instead of the babbitt to a similar bearing. Bearings were tested at different load-speed combinations in the fully flooded mode. Pad temperature distributions, collar temperatures and bearing friction torque were continuously measured. Test results show that the PTFE composite provides excellent thermal insulation so that pad thermal crowning is eliminated. PTFE-faced bearings operate with lower power loss and slightly higher collar temperatures compared to similar babbitted bearings.

Method for Solution of Lubrication Problems With Temperature and Elasticity Effects: Application to Sector, Tilting-Pad Bearings

1969 ◽  
Vol 91 (4) ◽  
pp. 634-640 ◽  
Author(s):  
V. Castelli ◽  
S. B. Malanoski
Keyword(s):  
Elastic Deformation ◽  
Efficient Method ◽  
Simultaneous Solution ◽  
Thrust Bearings ◽  
Variational Techniques ◽  
Tilting Pad ◽  
Tilting Pad Bearings ◽  
Energy Equations ◽  
Elasticity Effects

The importance of temperature and elasticity effects in bearings have been demonstrated by several authors. This paper offers an efficient method for the simultaneous solution of the Reynolds and energy equations and their coupling with elastic deformation results obtained by variational techniques. Results are presented for centrally pivoted, tilting-pad, sector, thrust bearings.

Centrifugal Effects in Misaligned Hydrostatic Thrust Bearings

1983 ◽  
Vol 105 (4) ◽  
pp. 621-624 ◽  
Author(s):  
Z. S. Safar
Keyword(s):  
Flow Rate ◽  
Load Capacity ◽  
Friction Torque ◽  
Centrifugal Forces ◽  
Thrust Bearings ◽  
Lubricant Flow

An analysis is conducted and solutions are provided for the effect of centrifugal forces on hydrostatic misaligned thrust bearings. The results show that centrifugal forces reduce considerably the load capacity, the friction torque and increase the lubricant flow rate. It is found that the effect of centrifugal forces is decreased as tilting of the bearing is increased.

Influence of new surface micro-structures on the performance behaviours of fluid film tilting pad thrust bearings

2021 ◽  
pp. 095440622110309
Author(s):  
JC Atwal ◽  
RK Pandey
Keyword(s):  
Mass Conservation ◽  
Performance Parameters ◽  
Algebraic Equations ◽  
The Finite Element Method ◽  
Thrust Bearings ◽  
Lubrication Equation ◽  
Tilting Pad ◽  
Minimum Film Thickness ◽  
Newton Raphson ◽  
Micro Structures

Performance parameters such as power loss, minimum film thickness, and maximum oil temperature of the sector-shaped tilting pad thrust bearings employing the new micro-structural geometries on pad surfaces have been investigated. The lubrication equation incorporating the mass-conservation issue is discretized using the finite element method and the solution of resulting algebraic equations is obtained employing a Newton-Schur method. The pad equilibrium in the analysis is established using the Newton-Raphson and Braydon methods. The influence of attributes of micro-structures such as depth, circumferential and radial positioning extents have been explored on the performance behaviours. It is found that with the new micro-structured pad surfaces, the performance parameters significantly improved in comparison to conventional plain and conventional rectangular pocketed pads.

Electrical pitting of tilting-pad thrust bearings: Modelling and experimental evidence

2016 ◽  
Vol 103 ◽  
pp. 475-486 ◽  
Author(s):  
Steven Chatterton ◽  
Paolo Pennacchi ◽  
Andrea Vania
Keyword(s):  
Experimental Evidence ◽  
Thrust Bearings ◽  
Tilting Pad

A Three-Dimensional Analysis of Thermohydrodynamic Performance of Sector-Shaped, Tilting-Pad Thrust Bearings

1983 ◽  
Vol 105 (3) ◽  
pp. 406-412 ◽  
Author(s):  
Kyung Woong Kim ◽  
Masato Tanaka ◽  
Yukio Hori
Keyword(s):  
Dimensional Analysis ◽  
Environmental Conditions ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
Dimensional Variation ◽  
Lubricant Viscosity

The thermohydrodynamic performance of the bearing is analyzed, taking into account the three-dimensional variation of lubricant viscosity and density. The effect of pivot position and operating and environmental conditions on the performance is studied. The present analysis is compared with the isoviscous or the two-dimensional analysis, and is found to predict the bearing performance more accurately.

On the Thermal Effects in the Design of Tilting-Pad Bearings Subjected to Inlet Pressure Build-Up

1991 ◽  
Vol 113 (3) ◽  
pp. 526-532 ◽  
Author(s):  
K. W. Kim ◽  
C. M. Rodkiewicz
Keyword(s):  
Thermal Effects ◽  
Center Of Pressure ◽  
Load Capacity ◽  
Inlet Pressure ◽  
Maximum Temperature ◽  
Pivot Point ◽  
Temperature Distributions ◽  
Tilting Pad ◽  
Tilting Pad Bearings ◽  
Force Coordinate

The presented analytical consideration of tilting-pad bearings incorporates simultaneously the changes in viscosity (due to viscous dissipation) and in the nonambient inlet pressure (due to momentum depletion within the fore-region). The solution provides the following quantities: film temperature distributions, pressure distribution, maximum temperature of the pad, load capacity, friction force, coordinate of the center of pressure, and coordinate of the pivot point. Comparison with the case when the inlet pressure is assumed to be ambient indicates the significance of the pressure build-up in the fore-region.

On the Optimum Groove Geometry for Herringbone Grooved Journal Bearings

2006 ◽  
Vol 128 (3) ◽  
pp. 585-593 ◽  
Author(s):  
A. M. Gad ◽  
M. M. Nemat-Alla ◽  
A. A. Khalil ◽  
A. M. Nasr
Keyword(s):  
Groove Depth ◽  
Radial Force ◽  
Journal Bearings ◽  
Friction Torque ◽  
Performance Characteristics ◽  
Width Ratio ◽  
Geometrical Parameters ◽  
Thrust Bearings ◽  
Circular Groove ◽  
Groove Profile

Recently, herringbone-grooved journal bearings have had important applications in miniature rotating machines. The scribed grooves, on either the rotating or stationary member of the bearing, can pump the lubricant inward, which generates supporting stiffness and improves the dynamic stability, especially for concentric operation. Most of the previous investigations that dealt with herringbone grooved journal bearings and grooved thrust bearings were theoretical. Few experimental attempts for the investigation of the performance characteristics of herringbone grooved journal bearings (HGJBs) and grooved thrust bearings have been done. All these investigations concentrated on rectangular and circular groove profiles of HGJBs. In order to improve the performance characteristics of HGJBs, a new design of the groove profile, the beveled-step groove profile, is introduced. The introduced groove profile is capable of increasing the pressure recovery at the divergence of the flow over the step. In addition, it increases the amount of oil pumped inward over the circular groove profile. Optimization processes were carried out experimentally, in order to obtain the optimal geometry of the introduced groove profile. The optimum geometrical parameters of the groove (groove angle α, groove width ratio β, and groove depth ratio Γ) are 29deg, 0.5, and 2.0, respectively, which give maximum radial force and maximum radial stiffness of the beveled-step HGJB. In order to check the effectiveness of the introduced beveled-step groove profile, the obtained results were compared with that for rectangular groove profile. The comparison shows that the introduced beveled-step HGJBs have higher radial force, higher load carrying capacity, and lower friction torque than the rectangular HGJBs.

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