Dynamic characteristics of composite tilting pad journal bearing for turbine/generator applications

On, Seung Yoon; Kim, Yun Seong; You, Jun Il; Lim, Jun Woo; Kim, Seong Su

doi:10.1016/j.compstruct.2018.06.095

Cited by 14 publications

(7 citation statements)

References 23 publications

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“…The paper showed a slight improvement on the system dynamic performance by using the hybrid lubrication instead of the passive one. Recently, the dynamic behaviors of a composite TPJB for turbine/generator applications were shown in [28]. Authors stated that the composite TPJB effectively decreased the rotor vibration and increased the stability and durability of the bearing system compared to the white metal bearing.…”

Section: Introductionmentioning

confidence: 99%

The Effect of the Pivot Stiffness on the Performances of Five-Pad Tilting Pad Bearings

2019

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The role of the pivot flexibility in tilting-pad journal bearings (TPJBs) has become essential, particularly for bearings working at high applied load and relatively high rotor speeds. Predictions from a simple bearing model with rigid pivots show incorrect estimation of the dynamic coefficients in comparison with the experimental results. Normally, the more flexible the pad pivot, the lower the dynamic coefficients because the stiffness of the pivot takes in series with the stiffness and damping of the oil film. This paper investigates the influence of pivot stiffness on the dynamic force coefficients of two different five-pad TPJBs as a function of the applied static load and excitation frequency: rocker-backed pivot and spherical pivot bearings. In order to highlight the effect of the pivot stiffness in the spherical pivot bearing, displacement restriction components and elastic copper made shims have been used. Firstly, a thermo-elasto-hydrodynamic model for the static and dynamic characteristics of the two bearings is described. This model takes into account the flexibility of both pad and pivot. The pivot stiffnesses calculated by means of the Hertz theory and those obtained by experiments have been introduced and compared in the model. The clearance profiles of two tested bearing and the shaft center loci obtained by measurement and prediction are also shown. The dynamic coefficients of the two bearings obtained from the numerical simulation were compared with the experimental results. By the analysis it can be concluded that the effect of the pivot flexibility on the clearance profile, the shaft locus and on the dynamic coefficients is very significant. More important, it is important to estimate the pivot stiffness of each single pad using experimental measurements.

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Section: Introductionmentioning

confidence: 99%

The Effect of the Pivot Stiffness on the Performances of Five-Pad Tilting Pad Bearings

2019

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“…The disturbance caused by the load variation is small without a strong impact. Consequently, the bearing force at the equilibrium position can be linearized in the following way (On et al, 2018):…”

Section: Dynamic Coefficientsmentioning

confidence: 99%

Investigation on static and dynamic characteristics of high-speed and heavy-load tilting pad journal bearings

Yan

Huang

2022

ILT

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Purpose Multitilting-pad journal bearings (MTPJBs) used in large-scale hydraulic turbines often suffer from complex operating conditions, which greatly influence the overall performance of the rotating machine. The purpose of this study is to establish a thermal-elastic-hydrodynamic lubrication model for MTPJBs that can predict the static and dynamic characteristics of high-speed and heavy-load MTPJBs under different operating conditions. Design/methodology/approach A thermo-elasto-hydrodynamic lubrication model considering the turbulence effect is proposed for high-speed and heavy-load TPJBs, which is solved using the coupled finite difference method and finite element method. The model considered the turbulence effect, thermal energy diffusion, viscosity–temperature–pressure relationship and elastic deformation of the pads. The influences of the operating conditions on static and dynamic characteristics of tilting pad journal bearings were analyzed in depth. Findings The operating conditions have a strong effect on the static properties of the bearings. The dynamic characteristics of the TPJB were the most influenced by the shaft speed. The effects of the load direction on the dynamic properties of the TPJB were much stronger than those of the static characteristics. Originality/value This study used analytical methods and models to provide theoretical guidance for evaluating lubricating characteristics, assembling conditions and overall health.

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“…Scholars have also carried out vibration mechanical behavior analysis of these engineering composite structures. For example, shafts, [10][11][12][13] blade, [14][15][16] rotor, 17 bearing, 18 sucker rod, 19 and leaf spring. 20 However, at present, the composite lightweight scheme suitable for high-speed warp knitting machines still needs to be improved.…”

Section: Introductionmentioning

confidence: 99%

Triaxial braided sandwich composite guide bar potentially used in high-speed warp knitting machine

Wang

Pan

et al. 2022

Journal of Industrial Textiles

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Integrated manufacturing technology was applied to fabricate a 3-D triaxial braided sandwich composite (TBSC) guide bar based on a real geometric shape. The axial compression, three-point bending, and vibration performance of bar specimens were investigated. Frequencies and vibration modes of the TBSC bar at free and constraint conditions were obtained by the numerical model, and the parametric analysis of different braiding angles was carried out. Effectiveness of the full-scale model was verified by vibration experiments. It is found that the frequency of TBSC and steel guide bar were close at the order 1 and 2; but when the order was higher than 2, the TBSC frequency was significantly improved. For the steel bar, axial periodic torsion and cross-section distortion were found at the orders 4, 5, 6, and 8; While for the TBSC structure, transverse bending was the main vibration deformation. Under a constrained state, the bending deformation was either localized at one end or in the middle of the bar, less than 1/3 length of the whole bar. The effect of braiding angle was significant on the deformation morphology. The increase of braiding angle had a negative effect on the frequency at the order 1 to 6. But such tendency changed at higher orders from 7 to 14. The frequency of [+15/0/-15]3 and [+75/0/-75]3 TBSC bars were much lower than that of [+30/0/-30]3 and [+45/0/-45]3 counterparts. If the maximum deformed displacement is considered, the [+45/0/-45]3 configuration will be the best choice, especially for vibration resistance at high frequency.

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Dynamic characteristics of composite tilting pad journal bearing for turbine/generator applications

Cited by 14 publications

References 23 publications

The Effect of the Pivot Stiffness on the Performances of Five-Pad Tilting Pad Bearings

The Effect of the Pivot Stiffness on the Performances of Five-Pad Tilting Pad Bearings

Investigation on static and dynamic characteristics of high-speed and heavy-load tilting pad journal bearings

Triaxial braided sandwich composite guide bar potentially used in high-speed warp knitting machine

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