PROSPECTS OF DECREASING POWER LOSSES IN A HYDROSTATIC THRUST BEARING

Tribologia ◽  
2017 ◽  
pp. 91-96 ◽  
Author(s):  
Filip WASILCZUK ◽  
Michał WASILCZUK ◽  
Michał WODTKE
Keyword(s):  
Fluid Dynamics ◽  
Axial Load ◽  
Thrust Bearing ◽  
Power Losses ◽  
Important Goal ◽  
Hydrodynamic Bearing ◽  
Thrust Bearings ◽  
Hydrostatic Bearing ◽  
Tilting Pad ◽  
Contemporary Technology

In numerous machines, axial load is carried by tilting pad thrust bearings known since the beginning of 20th century. These bearings are commonly bath lubricated, which is simple, does not require any additional pumps, and, due to this, such systems are highly reliable. In a contemporary technology, however, minimization of friction losses became an important goal of machinery improvement. Calculations based on elementary rules of fluid dynamics show that shearing losses in a specially designed hydrostatic bearing can be considerably smaller than the losses in a tilting pad hydrodynamic bearing. The aim of the research described in this paper was to check if the preliminary results can also be confirmed with the use of more advanced CFD calculations.

HYDROSTATIC THRUST BEARING WITH REDUCED POWER LOSSES

Tribologia ◽  
2018 ◽  
Vol 281 (5) ◽  
pp. 123-131
Author(s):  
Filip WASILCZUK ◽  
Michał WASILCZUK ◽  
Michał WODTKE
Keyword(s):  
Axial Load ◽  
Thrust Bearing ◽  
High Reliability ◽  
Rotating Machinery ◽  
Important Criterion ◽  
Power Losses ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
The Times ◽  
Strategic Goal

In many cases in rotating machinery, axial load is carried by tilting pad thrust bearings which have been developed since the beginning of 20th century. For high reliability and simplicity, most commonly the bearings are bath lubricated. In the times of sustainable development, however, minimization of friction losses becomes an important criterion for machinery assessment, and a strategic goal of their development. Performed calculations, based on elementary rules of fluid dynamics, showed that shearing losses in specially designed hydrostatic bearings can be considerably smaller than the losses in tilting pad hydrodynamic bearings. The aim of the research described in this paper was to check if the preliminary results presented earlier and conclusions of benefits of the further increase of the size of the hydrostatic pocket can be confirmed with the use of CFD calculations.

Load-Responsive Hydrodynamic Bearing for Downhole Drilling Tools

2006 ◽  
Vol 129 (1) ◽  
pp. 209-217 ◽  
Author(s):  
M. S. Kalsi ◽  
P. D. Alvarez ◽  
D. Somogyi ◽  
Aaron Richie
Keyword(s):  
Thrust Bearing ◽  
Dynamic Surface ◽  
Hydrodynamic Bearing ◽  
Thrust Bearings ◽  
Rock Formations ◽  
Drill Bits ◽  
Drilling Tools ◽  
Tilting Pad ◽  
Mixed Lubrication Regime ◽  
Cone Drill

A load-responsive hydrodynamic thrust bearing has been developed that has capabilities to operate under higher load and speed combinations than the current bearing designs used in roller cone drill bits, downhole drilling motors, and other downhole drilling tools. The bearing dynamic surface, which is initially flat, deflects elastically under load to provide an efficient hydrodynamic geometry that generates a lubricant film, with a minimum film thickness that varies from 0.25 to 2.0μm. The bearing operates with friction coefficients typically in the range of 0.003 to 0.005, which are significantly lower than the conventional roller cone bit thrust bearing designs that operate in a boundary/mixed lubrication regime. Lower friction will allow bit seals to run cooler, and higher load/speed capabilities will increase drilling efficiency and extend component life in hard rock formations. Additionally, the new bearing is suitable for applications where tilting pad thrust bearings are used, offering the advantage of being simple, compact, and more economical.

Studies in hydronamic thrust bearings II. Comparison of calculated and measured performance of tilting pads by means of interferometry

1975 ◽  
Vol 278 (1283) ◽  
pp. 367-384 ◽  
Keyword(s):  
Thrust Bearing ◽  
Detailed Comparison ◽  
Experimental Film ◽  
Thrust Bearings ◽  
Hydrostatic Bearing ◽  
Tilting Pad ◽  
High Degree ◽  
Very High ◽  
Chrome Layer ◽  
Theory And Experiment

In this novel use of interferometry the film shape of a thrust bearing can be determined to a very high degree of accuracy by making the runner of glass and coating it with a semi-reflecting chrome layer. The runner is loaded by a hydrostatic bearing immediately above the experimental pad. By making the chamber of the hydrostatic recess of glass and by using the fact that glass and oil have almost the same refractive index, fringes between the tilting pad and the chrome layer can be obtained. The heat conduction through the pad was found to be important. The agreement between the experimental film shape and that calculated in part I is surprisingly good. It is only the very complete map of the film shape that allows the detailed comparison of theory and experiment to be made.

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.

Performance of Elastic, Centrally Pivoted, Sector, Thrust-Bearing Pads—Part I

1961 ◽  
Vol 83 (2) ◽  
pp. 169-178 ◽  
Author(s):  
B. Sternlicht ◽  
J. C. Reid ◽  
E. B. Arwas
Keyword(s):  
Experimental Data ◽  
Approximate Calculation ◽  
Thrust Bearing ◽  
Full Scale ◽  
Fluid Film ◽  
Thermal Gradients ◽  
Thrust Bearings ◽  
Adiabatic Conditions ◽  
Tilting Pad

This is the first of three papers on the results of a recently completed study of the performance of tilting pad thrust bearings. It describes a method of analysis that was worked out for these bearings, which includes viscosity variations in the fluid film and an approximate calculation of the pad deflections caused by the hydrodynamic pressures. Equilibrium of moments is satisfied, laminar and adiabatic conditions are assumed, and the lubricant is incompressible. The two subsequent papers of this series will describe: (a) The results of an analysis which includes a more rigorous determination of pad deflections caused by hydrodynamic pressures and thermal gradients. (b) A comparison of analytical results with experimental data obtained in full-scale bearing tests.

Thrust Bearings for Power Gas Turbines

1971 ◽  
Author(s):  
A. J. Leopard
Keyword(s):  
Gas Turbines ◽  
Load Capacity ◽  
Point Of View ◽  
Power Losses ◽  
Service Experience ◽  
Thrust Bearings ◽  
Tilting Pad ◽  
Bearing Assembly ◽  
Design Requirements ◽  
New System

The design requirements of thrust bearings for power gas turbines are discussed with reference to designs which have given satisfactory service. The shortcomings of these designs are analyzed both from the point of view of efficiency and that of service experience. The development of a new system of lubrication designed to overcome these shortcomings is outlined. It is shown that this system, when applied to tilting pad thrust bearings in power turbines, can result in a simpler bearing assembly with increased load capacity and substantially ower power losses.

Influence of Groove Molded Lines on the Lubrication Performance of Water-Lubricated Spiral Groove Thrust Bearings

2013 ◽  
Vol 694-697 ◽  
pp. 538-542 ◽  
Author(s):  
Xiao Yan Liu ◽  
Jia Sheng Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thrust Bearing ◽  
Pressure Field ◽  
Load Capacity ◽  
Loading Capacity ◽  
Spiral Groove ◽  
Thrust Bearings ◽  
Pressure Fields ◽  
Lubrication Performance

The water lubrication performance of spiral groove thrust bearings was affected by different groove molded lines. The pressure fields and the load capacity of water-lubricated spiral groove thrust bearings with different groove molded lines were simulated by computational fluid dynamics. The results show that the spiral groove which can produce the best loading capacity and steadier pressure field is appropriate to water-lubricated spiral groove thrust bearing. The line spiral groove can be used for decrease the process difficult when the loading capacity require is low.

A semianalytical method for studying the performances of aerostatic thrust bearing

2018 ◽  
Vol 233 (4) ◽  
pp. 628-637
Author(s):  
Jianbo Zhang ◽  
Chunxiao Jiao ◽  
Donglin Zou ◽  
Na Ta ◽  
Zhushi Rao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Film Thickness ◽  
Reynolds Equation ◽  
Thrust Bearing ◽  
Separation Of Variables ◽  
Orifice Diameter ◽  
Thrust Bearings ◽  
Supply Pressure ◽  
Semianalytical Method

The solution of Reynolds equation and computational fluid dynamics are widely employed for the lubrication performance analysis of aerostatic thrust bearing. However, the solution of Reynolds equation may be inaccurate and cannot present detailed performance near orifice, while computational fluid dynamics method has low computational efficiency with time consumption in mesh generation and solving Navier–Stokes equations. In order to overcome the drawbacks of Reynolds equation and computational fluid dynamics, based on the method of separation of variables, a semianalytical method is developed for describing the characteristics of aerostatic bearings available. The method of separation of variables considering the initial and viscous effect is more accurate than the Reynolds equation and can present detailed performance near orifice in the aerostatic thrust bearings, while method of separation of variables has great computational efficiency compared to computational fluid dynamics. Meanwhile, the pressure distribution calculated by method of separation of variables is compared to the published experimental data and the results obtained by computational fluid dynamics. The comparative results indicate validity of the method. Furthermore, the influences of flow and geometry parameters, such as supply pressure, orifice diameter, film thickness, and bearing radius, on the characteristics of aerostatic thrust bearings with single orifice are studied. The results show that there exists pressure depression phenomenon near orifice. The depression phenomenon is strengthened with increase of film thickness and supply pressure and decrease of orifice diameter and bearing radius, while the maximum speed increases with strengthening of pressure depression due to decrease of minimum local pressure near orifice. Moreover, the bearing capacity increases with increase of supply pressure, orifice diameter, and bearing radius and decreases with increase of film thickness, while mass flow rate increases with supply pressure, orifice diameter, and film thickness and it is not sensitive to bearing radius.

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.

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