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.

Experimental Evaluation of Hydrodynamic Bearings for a High Speed Turbocharger

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Robley G. Kirk
Keyword(s):  
Limit Cycle ◽  
Experimental Evaluation ◽  
High Speed ◽  
Experimental Results ◽  
Fluid Film ◽  
Pressure Pulsations ◽  
The Past ◽  
Film Instability ◽  
Tilting Pad ◽  
Engine Testing

Many high speed turbochargers are known to operate with limit cycle vibration as a result of fluid-film instability. The goal of this research was to achieve a stable synchronous response with a minimum of self-excited nonsynchronous contribution. Those vibration components excited by the engine harmonics and exhaust pressure pulsations were not the target of this research. This paper will review the experimental results of the fixed geometry fluid-film bearing designs selected to replace the standard stock floating-ring design. In addition, the paper documents a novel radial tilting pad bearing concept that was designed to replace the fixed geometry bearings, with a minimum of modification to the stock bearing housing. A summary of the on-engine testing over the past seven years is documented in this paper.

Experimental Evaluation of Hydrodynamic Bearings for a High Speed Turbocharger

2013 ◽  
Author(s):  
Robley G. Kirk
Keyword(s):  
Limit Cycle ◽  
Experimental Evaluation ◽  
High Speed ◽  
Experimental Results ◽  
Fluid Film ◽  
Pressure Pulsations ◽  
The Past ◽  
Film Instability ◽  
Tilting Pad ◽  
Engine Testing

Many high speed turbochargers are known to operate with limit cycle vibration as a result of fluid-film instability. The goal of this research was to achieve a stable synchronous response with a minimum of self-excited non-synchronous contribution. Those vibration components excited by the engine harmonics and exhaust pressure pulsations were not the target of this research. This paper will review the experimental results of the fixed geometry fluid-film bearing designs selected to replace the standard stock floating-ring design. In addition, the paper documents a novel radial tilting pad bearing concept that was designed to replace the fixed geometry bearings, with a minimum of modification to the stock bearing housing. A summary of the on-engine testing over the past seven years is documented in this paper.

scholarly journals Improvement of Tilting-Pad Journal Bearing Operating Characteristics by Application of Eddy Grooves

Lubricants ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 18
Author(s):  
Eckhard Schüler ◽  
Olaf Berner
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Load Capacity ◽  
Fluid Film ◽  
Operating Characteristics ◽  
Fluid Film Bearings ◽  
Tilting Pad ◽  
Bearing Load ◽  
Bearing Loads ◽  
Tilting Pad Journal Bearing

In high speed, high load fluid-film bearings, the laminar-turbulent flow transition can lead to a considerable reduction of the maximum bearing temperatures, due to a homogenization of the fluid-film temperature in radial direction. Since this phenomenon only occurs significantly in large bearings or at very high sliding speeds, means to achieve the effect at lower speeds have been investigated in the past. This paper shows an experimental investigation of this effect and how it can be used for smaller bearings by optimized eddy grooves, machined into the bearing surface. The investigations were carried out on a Miba journal bearing test rig with Ø120 mm shaft diameter at speeds between 50 m/s–110 m/s and at specific bearing loads up to 4.0 MPa. To investigate the potential of this technology, additional temperature probes were installed at the crucial position directly in the sliding surface of an up-to-date tilting pad journal bearing. The results show that the achieved surface temperature reduction with the optimized eddy grooves is significant and represents a considerable enhancement of bearing load capacity. This increase in performance opens new options for the design of bearings and related turbomachinery applications.

The Development of Turboexpander-Generators for Gas Pressure Letdown Part I: Design and Analysis

2021 ◽  
Author(s):  
Rasish Khatri ◽  
Jeremy Liu ◽  
Freddie Sarhan ◽  
Ovais Najeeb ◽  
Hiroshi Kajita ◽  
...  
Keyword(s):  
High Speed ◽  
Field Testing ◽  
Magnetic Bearing ◽  
Gas Pressure ◽  
Loop Dynamics ◽  
Full Speed ◽  
Detailed Simulation ◽  
Bearing Design ◽  
Net Load

Abstract This paper describes the design and development of an innovative 280 kW and a 125 kW Turboexpander Generator (TEG) for natural gas pressure letdown (PLD) applications. The flange-to-flange TEG is supported by active magnetic bearings (AMB) and uses an advanced thrust balancing scheme to minimize the net load on the thrust bearing. The machine designs for the two TEG frame sizes are very similar to maintain commonality between parts. A review of the high-speed generator (HSG) and AMB design is provided. A complete AMB closed-loop dynamics study is presented, including a comprehensive rotordynamics and controls analysis. The touchdown bearing design is shown and discussed, and design details of the touchdown bearing resilient mount are presented. The touchdown bearings are given resilience with a tolerance ring. A detailed simulation of a rotor touchdown event at full speed is shown. The magnetic bearing controller (MBC) and variable speed drive (VSD) are located approximately 35 m from the TEG, exposed to the outside environment, and are not required to be explosion-proof. The prototype TEGs are intended to be manufactured and tested in Q1 2021. They will be commissioned, and field tested in Q2 2021. A follow-up paper detailing the mechanical testing and field testing of the units will follow in 2022.

Optimum Design of Fluid Film Bearing for HDD Spindle Considering the Tolerances

2010 ◽  
Author(s):  
Yuta Sunami ◽  
Masayuki Ochiai ◽  
Hiromu Hashimoto
Keyword(s):  
Optimum Design ◽  
High Speed ◽  
Low Noise ◽  
Production Costs ◽  
Fluid Film ◽  
Rotating Shaft ◽  
Fluid Film Bearings ◽  
Support Element ◽  
Characteristic Values ◽  
Bearing Characteristic

Fluid film bearings are widely used for high speed rotating machineries acting as rotating shaft support element. Especially, the bearings are widely applied to the OA equipments and IT devices. Optimization of bearing parameters is effective to improve the performance of the fluid film bearings since low noise and impact-proof characteristics are essential requirements for these equipments. On the other hand, bearings for miniaturized spindles are generally made by mass production process which will eventually requires reduction of production costs. In this paper, therefore small size HDD spindle using fluid film bearings is treated. Sensitivity analysis and optimum design that considered dimensional tolerances using the probabilistic techniques are conducted. As a result, the influence of bearing characteristic values on the occurrence of dimensional tolerances was clarified.

Evaluation of Pivot Stiffness for Typical Tilting-Pad Journal Bearing Designs

1988 ◽  
Vol 110 (2) ◽  
pp. 165-171 ◽  
Author(s):  
R. G. Kirk ◽  
S. W. Reedy
Keyword(s):  
High Speed ◽  
Fluid Film ◽  
Hertzian Contact ◽  
Tilting Pad ◽  
Hertzian Contact Stress ◽  
Bearing Stiffness ◽  
Stress And Deformation ◽  
The Individual ◽  
Stiffness And Damping ◽  
Tilting Pad Journal Bearing

The manufacturers of high speed turbomachinery are concerned with the accurate prediction of rotor response and stability. One major factor in the placement of system critical speeds and amplification factors is the stiffness and damping of both the fluid-film bearing and support structure. Typical calculated results for tilting-pad fluid-film bearings have neglected the influence of the point or line contact of the pivot support for the individual pads. This paper will review the equations developed considering the Hertzian contact stress and deformation theory and present the equations for pivot stiffness necessary for inclusion in tilting pad bearing computer programs. In addition, the influence of various standard pivot designs will be compared for typical fluid-film bearing stiffness and damping characteristics.

Effects of Turbulence and Viscosity Variation on the Dynamic Coefficients of Fluid Film Journal Bearings

1985 ◽  
Vol 107 (2) ◽  
pp. 256-261 ◽  
Author(s):  
D. F. Wilcock ◽  
O. Pinkus
Keyword(s):  
High Speed ◽  
Dynamic Stiffness ◽  
Journal Bearings ◽  
Fluid Film ◽  
Turbulent Regime ◽  
Dynamic Coefficients ◽  
Damping Characteristics ◽  
Fluid Film Bearings ◽  
Viscosity Variation ◽  
Stiffness And Damping

Many high-speed or large fluid film bearings operate in the turbulent regime. However, relatively little consideration has been given to the effects of turbulence and of the variation in viscosity on the dynamic stiffness and damping characteristics of the bearings. Since the dynamic behavior of the rotor supported on such bearings is often closely tied to the bearing dynamic coefficients, knowledge of them may be critical to both the design and the in-place correction of rotor instabilities. These effects are here considered in some detail on the basis of computer calculated analytical results, both in general dimensionless terms and with regard to a specific numerical example.

Turbocharger vibration shows nonlinear jump

2011 ◽  
Vol 18 (10) ◽  
pp. 1454-1461 ◽  
Author(s):  
R Gordon Kirk ◽  
Ali Alsaeed ◽  
Brian Mondschein
Keyword(s):  
Vibration Spectrum ◽  
Jump Condition ◽  
Journal Bearings ◽  
Frequency Content ◽  
Unstable Region ◽  
The Past ◽  
Fluid Film Bearings ◽  
Custom Design ◽  
Recent Developments ◽  
Bearing Design

Automotive turbochargers are known to operate into the self-excited unstable region. In the past these instabilities have been accepted as unavoidable, but recent developments in analysis and instrumentation may make it possible to reduce or eliminate them. A test stand has been developed at Virginia Tech to measure the vibrations of a 3.9 liter diesel engine stock turbocharger with both stock floating ring journal bearings and also custom design fixed geometry bearings. Vibration spectrum content clearly identifies the shaft instabilities and provides the basis for additional evaluation of future improved bearing design modifications. The current results, for custom fixed journal bearings, have clearly revealed a distinct jump with associated shift in the spectrum frequency content. This paper will document the recent tests of custom design fluid film bearings that have experienced this nonlinear jump condition.

Development of a High Speed Gas Bearing Test Rig to Measure Rotordynamic Force Coefficients

2011 ◽  
Vol 133 (10) ◽  
Author(s):  
J. Jeffrey Moore ◽  
Andrew Lerche ◽  
Timothy Allison ◽  
David L. Ransom ◽  
Daniel Lubell
Keyword(s):  
High Speed ◽  
High Amplitude ◽  
Fluid Film ◽  
Test Rig ◽  
Force Coefficient ◽  
Gas Bearings ◽  
Foil Bearings ◽  
Fluid Film Bearings ◽  
Wide Range ◽  
Gas Bearing

The use of gas bearings has increased over the past several decades to include microturbines, air cycle machines, and hermetically sealed compressors and turbines. Gas bearings have many advantages over traditional bearings, such as rolling element or oil lubricated fluid film bearings, including longer life, ability to use the process fluid, no contamination of the process with lubricants, accommodating high shaft speeds, and operation over a wide range of temperatures. Unlike fluid film bearings that utilize oil, gas lubricated bearings generate very little damping from the gas itself. Therefore, successful bearing designs such as foil bearings utilize damping features on the bearing to improve the damping generated. Similar to oil bearings, gas bearing designers strive to develop gas bearings with good rotordynamic stability. Gas bearings are challenging to design, requiring a fully coupled thermo-elastic, hydrodynamic analysis including complex nonlinear mechanisms such as Coulomb friction. There is a surprisingly low amount of rotordynamic force coefficient measurement in the literature despite the need to verify the model predictions and the stability of the bearing. This paper describes the development and testing of a 60,000 rpm gas bearing test rig and presents measured stiffness and damping coefficients for a 57 mm foil type bearing. The design of the rig overcomes many challenges in making this measurement by developing a patented, high-frequency, high-amplitude shaker system, resulting in excitation over most of the subsynchronous range.

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