Influence of Pad Pivot Friction on Tilting-Pad Journal Bearing Measurements—Part II: Dynamic Coefficients©

Wygant, Karl; Barrett, Lloyd; Flack, Ronald D.

doi:10.1080/10402009908982215

Cited by 22 publications

(10 citation statements)

References 5 publications

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“…For the speed, load and temperature ranges tested, the dynamic coefficient results for each speed agreed within the uncertainty of the data. Subsequently, the effect of pad pivot friction (Wygant et al, 1999), the effect of load orientation and effects of external excitation frequency and orbit magnitude on the dynamic coefficients of the tilting pad journal bearing were investigated using a similar approach to that of Flack et al (1993). Heshmat and Ku (1994) and Ku (1994) identified damping and stiffness coefficients of a self-acting compliant foil journal and thrust bearings, respectively.…”

Section: Methods Using An Excitedmentioning

confidence: 99%

Identification of Dynamic Bearing Parameters: A Review

Tiwari¹,

Lees²,

Friswell³

2004

shock vib digest

132

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In this paper, we present a review of the experimental identification of dynamic parameters of bearings in a rotating machine. Major emphasis is given to vibration-based identification methods and the review encompasses descriptions of experimental measurement techniques, mathematical modeling, parameter extraction algorithms and uncertainty in the estimates applied to a variety of bearings. The parameter extraction algorithms include the descriptions of governing equations of the rotor-bearing system and identification methods in both time and frequency domains. The identification techniques have been classified based on methods used to excite the system. The review includes a variety of bearings and similar components, which play an active link between the rotating and stationary parts of a machine. Based on the state of the art in bearing identification, conclusions are made and future directions are suggested.

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Section: Methods Using An Excitedmentioning

confidence: 99%

Identification of Dynamic Bearing Parameters: A Review

Tiwari¹,

Lees²,

Friswell³

2004

shock vib digest

132

View full text Add to dashboard Cite

show abstract

“…The five-pad tilting pad tests have included the effect of pad pivot friction [63] and varying preload [64] on identified bearing coefficients.…”

Section: Sinusoidal Excitation With Comprehensivementioning

confidence: 99%

“…The uncertainty analysis was based on subsequent bearing identification experiments, including 2-axial groove bearings [57,58]; other studies of the 3-lobe bearing include testing of the linearity assumption the effect of load orientation on coefficients [59,60], three independent shaft orbits and the orbits resulting in the lowest uncertainty were used to identify bearing coefficients for a 3-lobe journal bearing with 0.75 preload [61,62] and five-pad tilting pad bearings [63][64][65][66]. The five-pad tilting pad tests have included the effect of pad pivot friction [63] and varying preload [64] on identified bearing coefficients.…”

Section: Sinusoidal Excitation With Comprehensivementioning

confidence: 99%

A Review on Application of Dynamic Parameters of Journal Bearing for Vibration and Condition Monitoring

Babu

Raj²,

Lakshmanan

2015

J. mech.

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The journal bearings are used to support high-speed rotors in turbo machinery which often operate above the rotor first bending critical speed. This bearing provide both lateral support and dynamic coefficients: Stiffness, damping, and mass terms, related to machine vibrations. The various methods of identifying journal bearing dynamic characteristics, from measured data, obtained from different measurement systems, are reviewed. The various approaches to the bearing identification problem are discussed. The various data processing methods in the time and frequency domains are presented. Also, vibration and condition monitoring techniques are presented. In this review, the relative strengths and weaknesses of bearing are presented and developments and trends in improving bearing measurements are documented. Future trends of journal bearing are discussed.

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“…The optimal points in shaft orbits to extract the bearing parameters were addressed, which are related to numerical conditioning. The uncertainty analysis was used on subsequent bearing identification experiments, including 2-axial groove bearings [31,32], 3 lobe bearings [7,8,17,30], and five-pad tilting pad bearings [46,47,63,69]. Typical uncertainties in identified bearing coefficients were 3-20 percent, depending on the experiment.…”

Section: Sinusoidal Excitation With Comprehensive Uncertainty Analysismentioning

confidence: 99%

Identification Methods and Test Results for Tilting Pad and Fixed Geometry Journal Bearing Dynamic Coefficients – A Review

Dimond

Sheth

Allaire

et al. 2009

Shock and Vibration

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Fluid film journal bearings (FFBs) are used to support high-speed rotors in turbomachinery which often operate above the rotor first bending critical speed. The FFBs provide both lateral support and dynamic coefficients: stiffness, damping, and mass terms, related to machine vibrations. Detailed numerical values of the bearing dynamic characteristics are necessary for proper design and operation of rotating machinery.The methods of the identification of fluid film journal bearing static and dynamic characteristics, particularly the bearing stiffness, damping, and mass coefficients, from measured data, obtained from different measurement systems, is reviewed. Many bearing tests have been performed to validate a number of different theoretical models, including the classical Reynolds isoviscous model. More advanced bearing models include the thermohydrodynamic (THD), and thermoelastohydrodynamic (TEHD) approaches. The advanced models also include turbulence effects which are important as rotor speeds continue to increase. The range of measured bearing data no longer includes current operational conditions.The various approaches to the bearing identification problem are discussed, including the different force excitation methods of incremental loading, sinusoidal, pseudorandom, impulse, known/additional unbalance, and non-contact excitation. Also bearing excitation and rotor excitation approaches are discussed. Data processing methods in the time and frequency domains are presented. Methods of evaluating the effects of measurement uncertainty on overall bearing coefficient confidence levels are reviewed.In this review, the relative strengths and weaknesses of bearing identification methods are presented, and developments and trends in improving bearing measurements are documented. Future trends in journal bearing identification improvement are discussed.

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Influence of Pad Pivot Friction on Tilting-Pad Journal Bearing Measurements—Part II: Dynamic Coefficients©

Cited by 22 publications

References 5 publications

Identification of Dynamic Bearing Parameters: A Review

Identification of Dynamic Bearing Parameters: A Review

A Review on Application of Dynamic Parameters of Journal Bearing for Vibration and Condition Monitoring

Identification Methods and Test Results for Tilting Pad and Fixed Geometry Journal Bearing Dynamic Coefficients – A Review

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