The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings—Part II: Comparison Between Theory and Experiment

2007 ◽  
Vol 129 (4) ◽  
pp. 904-912 ◽  
Author(s):  
Niels Heinrichson ◽  
Axel Fuerst ◽  
Ilmar Ferreira Santos
Keyword(s):  
High Pressure ◽  
Film Thickness ◽  
Pressure Distribution ◽  
The Other ◽  
Oil Film ◽  
Thrust Bearings ◽  
Pressure Injection ◽  
Tilting Pad ◽  
Oil Injection ◽  
High Pressure Injection

This is Part II of a two-part series of papers describing the effects of high-pressure injection pockets on the operating conditions of tilting-pad thrust bearings. The paper has two main objectives. One is an experimental investigation of the influence of an oil injection pocket on the pressure distribution and oil film thickness. Two situations are analyzed: (i) when the high-pressure oil injection is turned off and (ii) when the high-pressure injection is turned on. The other objective is to validate a numerical model with respect to its ability to predict the influence of such a pocket (with and without oil injection) on the pressure distribution and oil film thickness. Measurements of the distribution of pressure and oil film thickness are presented for tilting-pad thrust bearing pads of ∼100cm2 surface area. Two pads are measured in a laboratory test rig at loads of ∼1.5MPa and ∼4.0MPa and velocities of up to 33m∕s. One pad has a plain surface. The other pad has a conical injection pocket at the pivot point and a leading-edge taper. The measurements are compared to theoretical values obtained using a three-dimensional thermoelastohydrodynamic (TEHD) numerical model. At the low load, the theoretical pressure distribution corresponds well with the measured values for both pads, although the influence of the pocket is slightly underestimated. At the high load, large discrepancies exist for the pad with an injection pocket. It is argued that the discrepancies are due mainly to geometric inaccuracies of the collar surface, although they may to some extent be due to the simplifications employed in a Reynolds equation description of the pocket flow. The measured and theoretical values of oil film thickness compare well at low loads and velocities. At high loads and velocities, discrepancies grow to up to 25%. This is due to the accuracy of the measurements. When using hydrostatic jacking the model predicts the start-up behavior well.

The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings—Part I: Theory

2007 ◽  
Vol 129 (4) ◽  
pp. 895-903 ◽  
Author(s):  
Niels Heinrichson ◽  
Ilmar Ferreira Santos ◽  
Axel Fuerst
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Pressure Injection ◽  
Pressure Profiles ◽  
Tilting Pad ◽  
Oil Injection ◽  
High Pressure Injection ◽  
Theoretical Results

This is Part I of a two-part series of papers describing the effects of high-pressure injection pockets on the operating conditions of tilting-pad thrust bearings. In Part I a numerical model based on the Reynolds equation is developed extending the three-dimensional thermoelastohydrodynamic (TEHD) analysis of tilting-pad thrust bearings to include the effects of high-pressure injection and recesses in the bearing pads. The model is applied to the analysis of an existing bearing of large dimensions and the influence of the pocket is analyzed. In the analysis, the high-pressure oil injection used for hydrostatic jacking is turned off (i.e., only the effect of the pocket is studied). It is shown that a shallow pocket positively influences the performance of the bearing because it has characteristics similar to those of a Rayleigh-step bearing. In Part II of the paper (Heinrichson, N., Fuerst, A., and Santos, I. F., 2007, ASME J. Tribol., 129(4), pp. 904–912) measurements of pressure profiles and oil film thickness for a test-pad are compared to theoretical results. The analysis of Part II deals both with flow situations, where the high-pressure injection is turned off, as well as with situations where it is turned on for hydrostatic jacking.

The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings: Part II — Comparison Between Theory and Experiment

2006 ◽  
Author(s):  
Niels Heinrichson ◽  
Axel Fuerst ◽  
Ilmar Ferreira Santos
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Three Dimensional ◽  
Leading Edge ◽  
Operating Conditions ◽  
Oil Film ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
High Pressure Injection ◽  
Theoretical Pressure

This is Part II of a two-part series of papers describing the effects of high pressure injection pockets on the operating conditions of tilting-pad thrust bearings. Measurements of the distribution of pressure and oil film thickness are presented for tilting-pad thrust bearing pads of approximately 100 cm2 surface area. Two pads are measured in a laboratory test-rig at loads of approximately 0.5, 1.5 and 4.0 MPa and velocities of up to 33 m/s. One pad has a plain surface. The other pad has a conical injection pocket at the pivot point and a leading edge taper. The measurements are compared to theoretical values obtained using a three dimensional thermoelasto-hydrodynamic (TEHD) numerical model. At low and intermediate loads the theoretical pressure distribution corresponds well to the measured values for both pads although the influence of the pocket is slightly underestimated. At high loads large discrepancies exist for the pad with an injection pocket. It is argued that this is likely to be due to the unevenness of the collar surface. The measured and theoretical values of oil film thickness compare well at low loads. At high loads discrepancies grow to up to 25 %. It is argued that this is due to the accuracy of the measurements.

The Influence of Injection Pockets on the Performance of Tilting-Pad Thrust Bearings: Part I — Theory

2006 ◽  
Author(s):  
Niels Heinrichson ◽  
Ilmar Ferreira Santos ◽  
Axel Fuerst
Keyword(s):  
High Pressure ◽  
Numerical Model ◽  
Reynolds Equation ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Model Based ◽  
Pressure Injection ◽  
Tilting Pad ◽  
High Pressure Injection

This is Part I of a two-part series of papers describing the effects of high pressure injection pockets on the operating conditions of tilting-pad thrust bearings. A numerical model based on the Reynolds equation is developed extending the three dimensional thermo-elasto-hydrodynamic (TEHD) analysis of tilting-pad thrust bearings to include the effects of high pressure injection and recesses in the bearing pad. The model is applied to the analysis of an existing bearing of large dimensions and the influence of the pocket is analyzed. It is shown that a shallow pocket positively influences the performance of the bearing as it has characteristics similar to those of a parallel step bearing.

Numerical Simulation of Oil Film State and Mechanical Performance of Heavy Hydrostatic Thrust Bearings

2013 ◽  
Vol 318 ◽  
pp. 148-152
Author(s):  
Yao Yao Hong ◽  
Li Jun Du ◽  
She Miao Qi
Keyword(s):  
Numerical Simulation ◽  
Temperature Distribution ◽  
Film Thickness ◽  
Pressure Distribution ◽  
Reynolds Equation ◽  
Mechanical Performance ◽  
The Finite Element Method ◽  
Oil Film ◽  
Thrust Bearings ◽  
Temperature And Pressure

The finite element method (FEM) is applied in the numerical simulation of heavy hydrostatic thrust bearings to study the influence of pressure and temperature on bearing deformation. The pressure distribution and the temperature distribution are obtained by solving the Reynolds equation and the energy equation. The bearing deformations caused by temperature and pressure are computed by imposing the two obtained distributions on the bearing. Because the pressure distribution and the temperature distribution are influenced by the oil film thickness and the oil film thickness is influenced by the bearing deformation, the numerical simulation is a process of iteration. The numerical results demonstrate that, in heavy hydrostatic thrust bearings, the thermal deformation and the mechanical deformation are both significant and can not be neglected. The influence of operation parameters on the anti-capsizing capability of heavy hydrostatic thrust bearings is also discussed. The obtained results reveal that, the anti-capsizing moment of the bearing increases with the decrease of the central thickness of the oil film.

Oil-film thickness and temperature measurements in PTFE and babbitt faced tilting-pad thrust bearings

2005 ◽  
Vol 219 (3) ◽  
pp. 179-185 ◽  
Author(s):  
D. M. C. McCarthy ◽  
S. B. Glavatskih ◽  
I Sherrington
Keyword(s):  
Film Thickness ◽  
Hydrodynamic Lubrication ◽  
Leading Edge ◽  
Frictional Torque ◽  
Trailing Edge ◽  
Oil Film ◽  
Thrust Bearings ◽  
Significant Difference ◽  
Tilting Pad ◽  
Facing Material

The influence of pad facing material on hydrodynamic lubrication in tilting-pad thrust bearings is investigated in terms of pad and oil-film temperatures and thicknesses. Two tilting-pad thrust bearings are examined: one with babbitt pad facing, the other with a layer of PTFE-based composite material. Frictional torque, pad, collar, and oil-film temperatures and thicknesses are all monitored by means of a comprehensive array of sensors mounted in the bearing and shaft. A considerably smaller range of temperature is seen in the steel backing immediately below the surface material for the PTFE faced pads. Oil-film temperatures measured at the mid-point on the pad trailing edge show no significant difference between the two bearings. Oil-film thicknesses in the two bearings are seen to differ. At the leading edge, oil-film thickness is thinner for the PTFE pad than for babbitt. However, at the trailing edge the PTFE pad has the thicker film.

Paper 13: Tilting Pad Thrust Bearings: Factors Affecting Performance and Improvements with Directed Lubrication

1969 ◽  
Vol 184 (12) ◽  
pp. 93-102 ◽  
Author(s):  
M. K. Bielec ◽  
A. J. Leopard
Keyword(s):  
Film Thickness ◽  
High Speed ◽  
Thrust Bearing ◽  
Specific Pressure ◽  
Factors Affecting ◽  
Oil Film ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
External Variables ◽  
Factors Affecting Performance

The effect on flooded tilting pad thrust bearing performance of a number of external variables is examined. At sliding speeds between 10 and 100 m/s, and for specific pressure between 15 bar and 55 bar, measurements were made of oil film thickness, bearing temperature, and power loss for various oil inlet systems, oil quantities, housing pressures, and degrees of misalignment. Power consumption in high-speed thrust bearings can be safely reduced by the use of directed lubrication with a drained casing, bearing temperature being reduced and oil film thickness increased.

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

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