Performance Characteristics of Tilting Pad Thrust Bearings at High Operating Speeds

1976 ◽  
Vol 98 (1) ◽  
pp. 81-88 ◽  
Author(s):  
J. W. Capitao
Keyword(s):  
Power Loss ◽  
Thrust Bearing ◽  
Experimental Program ◽  
Test Results ◽  
Transition Range ◽  
Thrust Bearings ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition ◽  
Tilting Pad ◽  
Bearing Loads

A full scale experimental program was conducted to investigate the influence of fluid film turbulence on the performance of the tilting-pad, self-equalizing type thrust bearing. Test results include data on centrally pivoted, 6-pad, 381-mm (15-in.) and 432-mm (17-in.) O.D. bearings operating with shaft speeds up to 10000 rpm and bearing loads ranging up to 3.447 MPa (500 psi). Data collected include bearing metal temperatures, bearing power loss, and observation of the laminar to turbulent transition range.

Performance of Thrust Bearings at High Operating Speeds

1974 ◽  
Vol 96 (1) ◽  
pp. 7-13 ◽  
Author(s):  
R. S. Gregory
Keyword(s):  
Research Program ◽  
Feed Rate ◽  
Power Loss ◽  
Thrust Bearing ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition ◽  
Tilting Pad ◽  
Bearing Loads

As part of a continuing research program, a standard 10 1/2 in. dia thrust bearing, of the tilting-pad, self-equalizing type, was tested at shaft speeds up to 11,000 rpm and bearing loads ranging up to 400 psi. The bearing and lube oil system were instrumented to measure bearing performance under laminar and turbulent operating conditions. The effects of varying the oil feed rate on bearing temperature and power loss are discussed in this paper. Some observations on the laminar to turbulent transition region are included.

Effects of High-Operating Speeds on Tilting Pad Thrust Bearing Performance

1976 ◽  
Vol 98 (1) ◽  
pp. 73-79 ◽  
Author(s):  
J. W. Capitao ◽  
R. S. Gregory ◽  
R. P. Whitford
Keyword(s):  
Experimental Data ◽  
Flow Rate ◽  
Power Loss ◽  
High Speed ◽  
Thrust Bearing ◽  
Full Scale ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
Speed Performance ◽  
Bearing Loads

A comparison of the high-speed performance characteristics of tilting-pad, self-equalizing type thrust bearings through two independent full-scale programs is reported. This paper presents experimental data on centrally pivoted, 6-pad, 267-mm (10 1/2-in.) and 304-mm (12-in.) O.D. bearings operating at shaft speeds up to 14000 rpm and bearing loads ranging up to 2.76 MPa (400 psi). Data presented demonstrate the effects of speed and loading on bearing power loss and metal temperatures. Included is a discussion of optimum oil supply flow rate based upon considerations of bearing pad temperatures and power loss values.

A Comparison of Tilting Pad Thrust Bearing Lubricant Supply Methods

1983 ◽  
Vol 105 (1) ◽  
pp. 39-45 ◽  
Author(s):  
A. M. Mikula ◽  
R. S. Gregory
Keyword(s):  
Experimental Data ◽  
Power Loss ◽  
Thrust Bearing ◽  
Leading Edge ◽  
Potential User ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
Edge Distribution

This paper compares three different lubricant supply methods—pressurized supply (flooded), spray feed, and leading edge distribution groove—and analyzes their influence on the performance of tilting pad, equalizing thrust bearings. The paper presents experimental data on 267 mm (10-1/2 in.) o.d. bearings, operating at shaft speeds up to 13,000 rpm with loads ranging up to 3.45 MPa (500 psi). The data presented demonstrate the effect each lubricant supply method has on bearing power loss and temperature. Conclusions are drawn, based upon the effectiveness of each design, to guide the potential user.

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.

scholarly journals On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Michal Wasilczuk ◽  
Grzegorz Rotta
Keyword(s):  
Power Loss ◽  
Power Plants ◽  
Thrust Bearing ◽  
Fluid Film ◽  
Total Power ◽  
Thrust Bearings ◽  
Oil Supply ◽  
Water Power ◽  
Lubricant Flow ◽  
Tilting Pad

Different systems of direct oil supply have been developed in order to facilitate efficient introduction of fresh lubricant to the oil gap and reduction of churning power loss in tilting pad thrust bearings. Up to now there is no documented application of the supply groove in large thrust bearings used in water power plants. The results of modeling lubricant flow in the lubricating groove of a thrust bearing pad will be presented in the paper. CFD software was used to carry out fluid film calculations. Such analysis makes it possible to modify groove geometry and other parameters and to study their influence on bearing performance. According to the results a remarkable decrease in total power loss due to avoiding churning losses can be observed in the bearing.

Further Test Results of the Leading-Edge-Groove (LEG) Tilting Pad Thrust Bearing

1988 ◽  
Vol 110 (1) ◽  
pp. 174-179 ◽  
Author(s):  
A. M. Mikula
Keyword(s):  
Experimental Data ◽  
Test Data ◽  
Power Loss ◽  
Thrust Bearing ◽  
Leading Edge ◽  
Temperature Data ◽  
Experimental Temperature ◽  
Test Results ◽  
Tilting Pad ◽  
Controlled Flow

This paper compares the LEG and pressurized controlled flow lubricant supply methods and evaluates their influence on the babbitt temperature and bearing power loss performance of a tilting pad, equalizing thrust bearing. The paper also presents new experimental temperature data from bidirectional testing of a unidirectional LEG bearing. The experimental data presented is from a 267 mm (10.5 in.) O.D. bearing, operating at shaft speeds up to 13000 rpm with applied loads that produced mean unit pressures of up to 3.45 MPa (500 psi). Conclusions are drawn based upon these test data.

An Investigation Into Laminar-to-Turbulent Transition in Tilting-Pad Bearings

1991 ◽  
Vol 113 (2) ◽  
pp. 303-307 ◽  
Author(s):  
G. E. Innes ◽  
H. J. Leutheusser
Keyword(s):  
Large Scale ◽  
Scale Model ◽  
Power Losses ◽  
Fluid Films ◽  
Thrust Bearings ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition ◽  
Fundamental Information ◽  
Large Scale Model ◽  
Tilting Pad

It has long been known that superlaminar flow occurs in lubrication fluid films above a critical speed. The consequence of the transition from laminar to superlaminar flow is an increase in power losses, with corresponding changes in heat generation and operating costs. While a formula exists to predict the onset of superlaminar flow for hydrodynamic journal bearings, there is no clear criterion for the transition in tilting-pad thrust bearings. The paper describes a detailed investigation, performed on a large-scale model of a single tilting-pad, to obtain fundamental information on the transition phenomenon. Based on this work a lower critical Reynolds number of laminar-to-turbulent transition is proposed.

The Leading-Edge-Groove Tilting-Pad Thrust Bearing: Recent Developments

1985 ◽  
Vol 107 (3) ◽  
pp. 423-428 ◽  
Author(s):  
A. M. Mikula
Keyword(s):  
Experimental Data ◽  
Power Loss ◽  
Thrust Bearing ◽  
Leading Edge ◽  
Thrust Bearings ◽  
Temperature Performance ◽  
Tilting Pad ◽  
Recent Developments ◽  
Bearing Design

This paper compares the leading edge groove and pressurized supply (flooded) lubricant supply methods, and analyzes their influence on the performance of equalizing tilting pad thrust bearings. This paper presents new experimental data on 6-shoe, 267 mm (10 1/2 in.) O.D. bearings, operating at shaft speeds up to 14000 rpm, with loads ranging up to 3.45 MPa (500 psi) for two different lubricants. The data presented details the power loss and babbitt temperature performance of two versions of the leading-edge-groove bearing design and contrasts the results with a pressurized supply bearing design.

Influence of Turbulence on Performance Characteristics of the Tilting Pad Thrust Bearing

1974 ◽  
Vol 96 (1) ◽  
pp. 110-116 ◽  
Author(s):  
J. W. Capitao
Keyword(s):  
Turbulent Flow ◽  
Power Loss ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Equal Area ◽  
Thrust Bearings ◽  
Finite Difference Equations ◽  
Tilting Pad ◽  
Oil Flow ◽  
Flow Theories

The influence of fluid film turbulence on the performance of centrally-pivoted tilting pad thrust bearings was analyzed. Major features of the analysis are: (1) today’s two predominant “engineering” turbulent flow theories are delineated and their quantitative predictions compared; (2) a spherical pad profile was assumed, and (3) an equal area technique was used in the finite difference equations. The results confirmed earlier predictions of increases in power loss and load capacity when compared to a laminar solution. Also, no significant differences were found between the results predicted by the two predominant turbulent flow theories. Power loss, load capacity, and hydrodynamic oil flow are given for 13, 15, and 17 in. sizes. Comparisons of laminar and turbulent numerical results are presented.

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