The Significance of Oil Thermal Properties on the Performance of a Tilting-Pad Thrust Bearing

2001 ◽  
Vol 124 (2) ◽  
pp. 377-385 ◽  
Author(s):  
Sergei B. Glavatskih ◽  
Michel Fillon ◽  
Roland Larsson
Keyword(s):  
Thermal Properties ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Friction Torque ◽  
Temperature Fields ◽  
Outer Diameter ◽  
Oil Film ◽  
Tilting Pad ◽  
Viscosity Grade ◽  
Mineral Base

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.

Steady State Performance Characteristics of a Tilting Pad Thrust Bearing

2000 ◽  
Vol 123 (3) ◽  
pp. 608-615 ◽  
Author(s):  
Sergei B. Glavatskikh
Keyword(s):  
Steady State ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Operating Conditions ◽  
Performance Characteristics ◽  
Shaft Speed ◽  
Oil Film ◽  
Tilting Pad ◽  
Bearing Load ◽  
Steady State Performance

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.

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.

A Performance Investigation into the Elastically Stepped and Shrouded Thrust Bearing

1967 ◽  
Vol 182 (1) ◽  
pp. 769-782 ◽  
Author(s):  
E. W. Hemingway
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Thrust Bearing ◽  
Frictional Resistance ◽  
Oil Film ◽  
Elastic Deflection ◽  
Tilting Pad ◽  
Thrust Pad ◽  
A Performance

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.

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.

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 Tapered-Land Thrust Bearing

1956 ◽  
Vol 23 (4) ◽  
pp. 581-583
Author(s):  
C. F. Kettleborough
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Maximum Load ◽  
Numerical Calculations ◽  
Oil Film ◽  
Unit Width ◽  
Tilting Pad ◽  
Better Than

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.

Oil Film Thickness in Lightly-Loaded Roller Bearings

1974 ◽  
Vol 16 (6) ◽  
pp. 386-390 ◽  
Author(s):  
H. Bahadoran ◽  
R. Gohar
Keyword(s):  
Film Thickness ◽  
Similar Condition ◽  
Thrust Bearing ◽  
Roller Bearing ◽  
Optical Interferometry ◽  
Oil Film ◽  
Roller Bearings ◽  
Tapered Roller

The effects of speed, load and roller geometry on the oil film thickness and shape in a complete roller bearing are demonstrated experimentally by means of optical interferometry. At quite moderate roller speeds, increase of film thickness becomes inhibited. This effect is attributed to a truncated inlet meniscus, a similar condition having been observed elsewhere with a ball-and-plate machine and with a model of a tapered-roller thrust bearing.

Effect of Thermal Properties of a Coated Elastohydrodynamic Lubrication Line Contact Under Various Slide-to-Roll Ratios

2017 ◽  
Vol 139 (7) ◽  
Author(s):  
Huaiju Liu ◽  
Caichao Zhu ◽  
Zonglin Gu ◽  
Zhanjiang Wang ◽  
Jinyuan Tang
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Elastohydrodynamic Lubrication ◽  
Temperature Fields ◽  
Line Contact ◽  
Oil Film ◽  
Line Contacts ◽  
Energy Equations ◽  
Thermal Conductivities

A numerical thermal elastohydrodynamic lubrication (EHL) model is developed for coated line contacts by considering both the mechanical properties and the thermal properties of the coating and the substrate. The temperature fields within the oil film and within the solids are solved by deriving the energy equations for the solids and the oil film. Heat continuity conditions are satisfied at the interfaces between the solids and the oil film, and the coating/substrate interfaces. Effects of the slide-to-roll ratio (SR), the thermal conductivities of the coating bodies, and the oil film on temperature fields are studied.

scholarly journals Analysis of Dynamic Engaged Characteristics of Wet Clutch in Variable Speed Transmission of a Helicopter

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1474
Author(s):  
Heyun Bao ◽  
Tongjing Xu ◽  
Guanghu Jin ◽  
Wei Huang
Keyword(s):  
Film Thickness ◽  
Bearing Capacity ◽  
Friction Torque ◽  
Rate Of Change ◽  
Lubricating Oil ◽  
Oil Film ◽  
Capacity Model ◽  
Wet Clutch ◽  
Friction Plate

The working principle and motion process of an aviation wet clutch are analyzed. The initial velocity before the friction pair engaged is solved. The transient Reynolds equation is modified, and an oil film bearing capacity model and a micro-convex bearing capacity model are derived. The film thickness equation between N friction pairs and a pressure-plate is derived. A dynamic engaged model of springs, pistons, friction pairs, and pressure plates are established. The torque balance equation is established of two pairs of friction pairs. The friction torque, rate of change in the oil film, and law of relative change in speed are obtained. The results demonstrate that the spring preload and the viscosity of the lubricating oil have a significant influence on the engagement characteristics. Increasing the quality of the friction plate will reduce the time of engagement, whereas the quality of the friction plate has slight effect on the friction torque characteristics and oil film thickness. The initial speed generated by the collision process will reduce the output speed, sharply increase the torque peak at the lock, and increase the shift shock.

Numerical Investigation of the Flow in a Hydrodynamic Thrust Bearing With Floating Disk

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Magnus Fischer ◽  
Andreas Mueller ◽  
Benjamin Rembold ◽  
Bruno Ammann
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Rotational Velocity ◽  
Control Unit ◽  
Axial Direction ◽  
Lubricating Oil ◽  
Temperature Dependent ◽  
Temperature Dependent Viscosity ◽  
Axial Thrust ◽  
Oil Film

In this paper we present a novel method for the numerical simulation of flow in a hydrodynamic thrust bearing with floating disk. Floating disks are commonly employed in turbochargers and are situated between the thrust collar, which is rotating at turbocharger speed, and the static casing. A floating disk reduces wear, improves the skew compensating capacity of the bearing, and is freely movable in the axial direction. The simulation model presented combines a commercial flow solver (ANSYS CFX) with a control unit. Based on physical principles and a predefined axial thrust, the control unit automatically sets the rotational speed of the floating disk, the mass flow of the oil supply, and the oil film thickness between the rotating disk and the casing wall and collar, respectively. The only additional inputs required are the temperature and the pressure of the oil at the oil feed and the turbocharger speed. The width of the computational grid of the thin lubricating oil film in the gaps is adjusted using a mesh-morphing approach. The temperature-dependent variation in viscosity is included in the model. The calculated solution of the flow field in the domain, the oil film thickness, and the resulting rotational velocity of the floating disk are validated against experimental data and demonstrate favorable agreement. The influence of uncertainties in the measurements and the behavior of the systems are thoroughly investigated in parametric studies that reveal the key influencing factors. These are the temperature-dependent viscosity of the oil, the axial thrust, and turbulence effects in the supply grooves and ducts of the floating disk. Using the model presented here, it is now possible to predict design variants for this type of bearing.

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