Steady State Performance Characteristics of a Tilting Pad Thrust Bearing

2000 ◽  
Vol 123 (3) ◽  
pp. 608-615 ◽  
Author(s):  
Sergei B. Glavatskikh

The paper reports results of the experimental investigation into the steady state performance characteristics of a tilting pad thrust bearing typical of design in general use. Simultaneous measurements are taken of the pad and collar temperatures, the pressure distributions, oil film thickness, and power loss as a function of shaft speed, bearing load, and supplied oil temperature. The effect of operating conditions on bearing performance is discussed. A small radial temperature variation is observed in the collar. A reduction in minimum oil film thickness with load is approximately proportional to p−0.6, where p is an average bearing pressure. It has also been found that the oil film pressure profiles change not only due to the average bearing load but also with an increase in shaft speed and temperature of the supplied oil.

Author(s):  
Niels Heinrichson ◽  
Axel Fuerst ◽  
Ilmar Ferreira Santos

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.


1979 ◽  
Vol 101 (2) ◽  
pp. 190-197 ◽  
Author(s):  
B. Fantino ◽  
J. Frene ◽  
J. Du Parquet

The effect of the deformation of an automotive connecting-rod on the oil film characteristics are studied. The simultaneous elastic deformation and pressure distribution are obtained by iterative methods in steady-state conditions under realistic speeds and loads (5500 rpm, 25,000 N). Plane elasticity relations are used in this study. The following parameters are investigated: —bearing characteristics: bearing thickness B and bearing clearance C, —operating conditions: journal speed N and applied load W, —lubricant: viscosity μ0 and piezoviscous coefficient α. As a result of the deformation, the maximum pressure and the attitude angle are decreased and the relative eccentricity is greatly increased. The minimum oil film thickness is slightly but systematically decreased. The piezoviscosity effect is noticeable only at high loads: it increases slightly the oil film thickness and the maximum pressure. An empirical dimensional equation for the minimum oil film thickness hm is derived numerically for the bearing considered. Thus: hm∼μ0NW0.5(1+0.06108α)B0.12C0.09


1984 ◽  
Vol 106 (4) ◽  
pp. 492-498 ◽  
Author(s):  
Vilmos Simon

The full thermal elastohydrodynamic analysis of the lubrication of rider rings is presented. A numerical solution of the coupled Reynolds, elasticity, energy, and Laplace’s equations for the oil film thickness, pressure, and temperature and rider rings temperatures is obtained. The temperature variation across the oil film is included. The real rider ring geometry is treated. The effect of the operating conditions on the performance characteristics is discussed.


2009 ◽  
Vol 131 (2) ◽  
Author(s):  
B. S. Shenoy ◽  
R. Pai

In an externally adjustable fluid film bearing, the hydrodynamic conditions can be changed as required in a controlled manner. The principal feature of the bearing is the facility to adjust its radial clearance and circumferential film thickness gradient. Unlike a tilting pad bearing, this bearing can have radial adjustments. The tilt adjustments are obtained by providing flexibility to the pad at one corner. This paper deals with the effect of turbulence on the steady state performance characteristics of a centrally loaded 120 deg single pad externally adjustable fluid film bearing. The bearing has an aspect ratio of 1 and operates over a wide range of eccentricity ratios with different radial and tilt adjustments. The Reynolds equation is solved numerically using the finite difference method. The linearized turbulence model of Ng and Pan (1965, “A Linearized Turbulent Lubrication Theory,” ASME J. Basic Eng., 87, pp. 675–688) as well as the simplified adiabatic model of Pinkus and Bupara (1979, “Adiabatic Solutions for Finite Journal Bearings,” ASME J. Lubr. Technol., 101, pp. 492–496) are incorporated in the solution scheme. The static performance characteristics calculated are presented in terms of load carrying capacity, attitude angle, friction variable, and Sommerfeld number. A comparative study with the combination of adjustments predicts that the static performance of the bearing is superior with negative radial and tilt adjustments.


2001 ◽  
Vol 124 (2) ◽  
pp. 377-385 ◽  
Author(s):  
Sergei B. Glavatskih ◽  
Michel Fillon ◽  
Roland Larsson

This paper is a report into an experimental and theoretical investigation of the effect of oil thermal properties on the performance of a tilting-pad thrust bearing. Three oils, namely poly-α-olefin, ester and mineral base, were chosen for this study. These oils all have same viscosity grade (ISO VG46) but differ in their rates of viscosity variation with temperature and in their heat capacity and thermal conductivity values. Mineral base oil of a higher viscosity grade (ISO VG68) was also analyzed for comparison. Experimental data were obtained from an equalizing tilting-pad thrust bearing with an outer diameter of 228.6 mm operating in a flooded lubrication mode. Simultaneous measurements of pad and collar temperatures, friction torque, pressures and oil film thickness were taken. In the tests, oil supply temperature and flow rate were held constant for all load-speed combinations. The theoretical analysis of oil performance was based on a three-dimensional TEHD model. In the analysis, thermal effects were locally taken into account and heat transfer into the pads was considered. The displacements of the active surface of the pads, due to pressure and temperature fields, were determined. The effect of initial pad crowning on the oil film thickness is discussed. Experimental and theoretical results are compared and analyzed in terms of the inlet and outlet oil film thickness, bearing operating temperature and power loss.


1967 ◽  
Vol 182 (1) ◽  
pp. 769-782 ◽  
Author(s):  
E. W. Hemingway

An experimental investigation is reported in which a stepped and shrouded thrust pad was formed from an initially plane pad face by elastic deflection caused by pressures generated hydrodynamically in the oil film. The pad shape was optimized experimentally and it produced thicker films than a comparable tilting pad bearing but with higher frictional resistance. Pressure and film thickness contours were investigated and plotted. A comparison is made with stepped pad bearing results. This paper is based on sections of a thesis presented in 1966 for the degree of Ph.D., University of London.


1981 ◽  
Vol 103 (1) ◽  
pp. 195-203 ◽  
Author(s):  
V. Simon

The full thermal elastohydrodynamic analysis of the lubrication of hypoid gears is presented. A numerical solution of the coupled Reynolds, elasticity and energy equations for the pressure, temperature and film thickness is obtained. The temperature variations across the oil film and in the pinion and gear teeth are included. The real tooth geometry of the modified hypoid gears is treated. The effect of the operating conditions on the performance characteristics is discussed.


2021 ◽  
Vol 233 ◽  
pp. 01007
Author(s):  
Chen Shuo ◽  
Zhang Heng

The ship power propulsion system is the "heart" of the ship, and the ship propulsion shafting is the core unit of the ship power propulsion system, and it is an indispensable part of the ship's propulsion torque and thrust transmission. The operating status of the propulsion shafting directly affects the operating conditions of the ship, and even the life of the ship. Bearing load is one of the most important manifestations of the operating state of the propulsion shafting. Focusing on changes in the bearing load can better study the operating state of the propulsion shafting. The research on the steady-state load of ship propulsion shafting meets the needs of ship development and has great value for practical engineering applications. This paper takes the ship propulsion shafting-oil film-bearing structure system as the research object. Through the steady-state load mathematical model of ship propulsion shafting bearings, it reveals the coupling relationship among ship propulsion shafting bearing load, oil film force, and journal position, and establishes the ship The steady-state load calculation method of the propulsion shafting bearings solves the basic theoretical problems of modeling and analysis of the steady-state operating state of the ship's propulsion shafting, and provides theoretical support for the safety prediction, management and evaluation of the ship's propulsion shafting operation.


Author(s):  
M. K. Bielec ◽  
A. J. Leopard

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.


1956 ◽  
Vol 23 (4) ◽  
pp. 581-583
Author(s):  
C. F. Kettleborough

Abstract Neglecting side leakage the maximum load capacity which can be carried per unit width is obtained when there is a stepped convergence to the oil film. However, when side leakage is considered the stepped bearing is only slightly better than the tilting-pad bearing, this being due to the fact that the maximum oil pressure occurs at the step where the oil-film thickness is a maximum and hence there is easy means of escape for oil. The tapered-land bearing does not suffer from this disadvantage and computations have been carried out which show that the maximum load this bearing is capable of supporting is about 14 per cent greater than the maximum load capable of being supported by the tilting-pad bearing, both cases not neglecting side leakage. Some numerical calculations are made.


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