scholarly journals Discussion: “Four Pad Tilting Pad Bearing Design and Application for Multistage Axial Compressors” (Nicholas, J. C., and Kirk, R. G., 1982, ASME J. Lubr. Technol., 104, pp. 523–529)

1982 ◽  
Vol 104 (4) ◽  
pp. 530-530
Author(s):  
R. D. Flack
Keyword(s):  
Axial Compressors ◽  
Tilting Pad ◽  
Bearing Design ◽  
Design And Application

Four Pad Tilting Pad Bearing Design and Application for Multistage Axial Compressors

1982 ◽  
Vol 104 (4) ◽  
pp. 523-529 ◽  
Author(s):  
J. C. Nicholas ◽  
R. G. Kirk
Keyword(s):  
Test Stand ◽  
Operating Speed ◽  
Design Studies ◽  
Peak Response ◽  
Analytical Design ◽  
Rotor Systems ◽  
Axial Compressors ◽  
Tilting Pad ◽  
Speed Range ◽  
Bearing Design

The advantages of operating multistage axial compressors on 4 pad tilting pad bearings are discussed and compared to other fixed bore and tilting pad bearing designs. These advantages include operation free of subsynchronous vibration and, with between pivot loading, placement of peak response speeds well outside of the operating speed range. Examples of analytical design studies of 3 actual rotor systems are presented and discussed to illustrate the design recommendations. Test stand results are also included for 3 axial compressors to help substantiate the analytical results.

Five Pad Tilting Pad Bearing Design and Lateral Vibration Characteristics of Small Gas Turbine Supported by It and Roller Bearing

2011 ◽  
Author(s):  
Jin Woong Ha ◽  
Ji Ho Myung ◽  
Jhin Ik Suk
Keyword(s):  
Rigid Body ◽  
Gas Turbine ◽  
Dynamic Properties ◽  
Roller Bearing ◽  
Rigid Body Mode ◽  
Conical Shape ◽  
Tilting Pad ◽  
Bearing Design ◽  
Industrial Gas Turbine ◽  
Selection Of

In tilting pad bearing design process, the selection of the proper configuration type of either a Load-Between-Pad (LBP) or Load-On-Pad (LOP) as well as preload and pivot offset conditions is to be carefully considered. Also the bearing needs to be designed in order to be suited for the rotor-bearing system and operating condition. In this paper, it is observed that the static and dynamic characteristics of a five pad tilting pad bearing for the LBP and LOP configurations are influenced by the variation of preload and pivot offset. In this context, rotor dynamic analysis of the 5 MW industrial gas turbine supported by the tilting pad bearing at the front and roller bearing at the rear is carried out based on the dynamic coefficients of the tilting pad bearing investigated. The result shows that two rigid body critical modes experience various changes according to the influence of the tilting pad bearing uniquely applied to one side of this machine. Mainly, the second critical speed, the rigid body mode of conical shape with high whirling in the tilting pad bearing, is significantly changed by preload and pivot offset regardless of the LBP and LOP configurations. And the first critical mode, the rigid body mode of conical shape with high whirling in the roller bearing, is sensitively affected by preload applied to the LOP configuration and by its asymmetric dynamic properties.

Experimental Study of Thermal Effects in Tilting-Pad Journal Bearings at High Operating Speeds

1996 ◽  
Vol 118 (3) ◽  
pp. 532-538 ◽  
Author(s):  
C. Bouchoule ◽  
M. Fillon ◽  
D. Nicolas ◽  
F. Barresi
Keyword(s):  
Thermal Effects ◽  
Applied Load ◽  
Journal Bearings ◽  
Test Machine ◽  
Power Losses ◽  
Test Bed ◽  
Tilting Pad ◽  
Oil Flow ◽  
Bearing Design ◽  
Tilting Pad Journal Bearings

In this work, a test machine, experimental results and the comparison between theoretical TEHD results and experimental data are presented. The tested bearings are located in two speed increasing and reduction gearboxes (back-to-back test bed). The shaft is driven by a 1 MW motor. The bearing diameter and the bearing length are equal to 160 mm. The rotational speed varies from 2700 rpm (22 m/s) to 11,880 rpm (100 m/s). The applied load is up to 88,000 N. Temperatures in the bearing (film/pad interface, oil, pad and housing), power losses and oil flow are measured. The influence of the bearing design and of the pivot position on the pad is analyzed.

Compliant Hybrid Gas Bearing Using Integral Hermetically Sealed Squeeze Film Dampers

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Bugra Ertas
Keyword(s):  
Squeeze Film ◽  
Force Coefficients ◽  
Overall Design ◽  
Single Piece ◽  
Squeeze Film Dampers ◽  
Tilting Pad ◽  
Support Force ◽  
Bearing Design ◽  
Gas Bearing ◽  
Gaining Insight

AbstractThis paper focuses on an integral gas-film lubricated bearing concept developed to enable the oil-free operation of super-critical carbon dioxide (sCO2) turbomachinery. The externally pressurized tilting pad bearing concept possesses a flexible bearing support with an integral hermetically sealed squeeze film damper. Unlike the past concepts using modular hermetic squeeze film dampers presented, the bearing design in this work utilizes advanced manufacturing methods to yield an integral single piece design in efforts to reduce space envelope, cost, and improve overall design reliability. The paper advances a detailed description of the bearing design and identification of bearing support force coefficients. Nonrotating benchtop tests show the influence of vibration amplitude, frequency, and damper cavity pressurization on force coefficients for two different viscosity fluids. Results indicate an increase in stiffness and a decrease in damping when increasing the frequency of excitation. Damper cavity pressurization was shown to eliminate squeeze film cavitation for the vibration amplitudes and frequency range in the study. Additionally, the paper advances a transient fluid–structure interaction (FSI) analysis aimed at gaining insight on the interaction of flexible elements bounding a hermetic fluid volume experiencing sinusoidal vibratory motion. The analysis considers an idealized damper model with and without a vibration transmission post while varying diaphragm modulus of elasticity for three excitation frequencies. Computational results were able to capture the increase in stiffness and the decrease in damping and show that the flexibility of the bounding elements influence the damper cavity volume change and phase ultimately affecting dynamic cavity pressures and force coefficients.

Diesel Engine Turbocharger Stabilized With Novel Tilting Pad Bearing Design

2012 ◽  
Author(s):  
R. Gordon Kirk ◽  
Matthew Enniss ◽  
Daniel Freeman ◽  
Andrew Brethwaite
Keyword(s):  
High Speed ◽  
Fluid Film ◽  
Pressure Pulsations ◽  
The Past ◽  
Fluid Film Bearings ◽  
Film Instability ◽  
Tilting Pad ◽  
Full Speed ◽  
Bearing Design ◽  
Engine Testing

Many high speed turbochargers operate with limit cycle vibration as a result of fluid-film instability. This problem has been under investigation for the past seven years. Only now has a turbocharger with fluid film bearings been run to full speed and loaded, with essentially no bearing induced sub-synchronous vibration. The goal of this research was to have a stable synchronous response with a minimum of non-synchronous contribution excited only by the engine dynamics and exhaust pressure pulsations. Previous papers have documented experimental results of the fixed geometry bearing designs. This paper documents a new, modified tilting pad bearing concept that has replaced the fixed geometry bushings with minimal modifications to the stock bearing housing. The summary of the on-engine testing over the past year is documented in this paper.

HYDRODYNAMIC THRUST BEARINGS WITH POLYMER LINING

Tribologia ◽  
2016 ◽  
Vol 268 (4) ◽  
pp. 225-237 ◽  
Author(s):  
Michał WODTKE
Keyword(s):  
Polymeric Materials ◽  
Industrial Applications ◽  
Hydrodynamic Bearings ◽  
Thrust Bearings ◽  
Sliding Surfaces ◽  
Current State ◽  
Tilting Pad ◽  
History Of ◽  
Bearing Design ◽  
Experimental Researches

Polymeric linings of sliding surfaces of the hydrodynamic bearings have been used successfully for over 50 years. Despite of their long history of operation and research, they have not become widespread in industrial applications. This fact may be surprising, considering the conclusions that have been published concerning bearing operation and design. This paper summarizes the current state of the art of the tilting-pad thrust bearings with a polymer lining of pad sliding surfaces. Bearing design and the most commonly used polymeric materials are described. The results of the latest theoretical and experimental researches by both bearing manufacturers and at scientific centres are presented. Observed properties of the bearings with polymer lining were compared to the properties of the bearings covered with Babbitt, which is the most frequently material used as lining for hydrodynamic bearings.

Constrained Optimization of Gas Turbine Tilting Pad Bearing Designs

2005 ◽  
Vol 128 (4) ◽  
pp. 873-878 ◽  
Author(s):  
Anders Angantyr ◽  
Jan-Olov Aidanpää
Keyword(s):  
Constrained Optimization ◽  
Gas Turbine ◽  
Power Loss ◽  
Difficult Problem ◽  
Search Method ◽  
Constraint Handling ◽  
System Level ◽  
Tilting Pad ◽  
Handling Technique ◽  
Bearing Design

This paper presents the constrained optimization of the tilting pad bearing design on a gas turbine rotor system. A real coded genetic algorithm with a robust constraint handling technique is used as the optimization method. The objective is to develop a formulation of the optimization problem for the late bearing design of a complex rotor-bearing system. Furthermore, the usefulness of the search method is evaluated on a difficult problem. The effects considered are power loss and limiting temperatures in the bearings as well as the dynamics at the system level, i.e., stability and unbalance responses. The design variables are the bearing widths and radial clearances. A nominal design is the basis for comparison of the optimal solution found. An initial numerical experiment shows that finding a solution that fulfills all the constraints for the system design is likely impossible. Still, the optimization shows the possibility of finding a solution resulting in a reduced power loss while not violating any of the constraints more than the nominal design. Furthermore, the result also shows that the used search method and constraint handling technique works on this difficult problem.

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