Dynamic characteristics of hydrodynamically lubricated fixed-pad thrust bearings

In the present paper, a study of stiffness and damping in sector-pad micro thrust bearings with artificial surface texturing is presented, based on computational fluid dynamics (CFD) simulations. The bearing pads are modeled as consecutive three-dimensional independent microchannels, each consisting of a smooth rotating wall (rotor) and a partially textured stationary wall (stator). CFD simulations are petformed, consisting in the numerical solution of the Navier-Stokes equations for incompressible isothermal flow. The goal of the present study is to characterize the dynamic behavior of favorable designs, identified in previous optimization studies, comprising parallel and convergent thrust bearings with rectangular texture patterns. To this end, a translational degree of freedom (DOF) along the thrust direction and a rotational (tilting) DOF of the rotor are considered. By implementing appropriate small perturbations around the equilibrium (steady-state) position and processing the simulation results, the stiffness and damping coefficients of the bearing are obtained for each DOF. The computed dynamic coefficients of textured thrust bearings are compared to those of conventional (smooth slider) designs. It is found that the dependence of bearing stiffness and damping on geometrical parameters exhibits the same trends for both DOFs. Both stiffness and damping are found to increase with bearing width. In general, increasing the bearing convergence ratio results in iticreased bearing stiffness and decreased damping. Finally, the present results demonstrate that properly textured parallel sliders are characterized by an overall dynamic performance that is superior to that of smooth converging sliders.

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“…7{b), the results are compared against the published data of Ref. [23] (Reynolds equation), illustrating a very good agreement.…”

Section: (C) Selection Of Parameters T* and Tpmentioning

confidence: 58%

“…The dynamic characteristics of untextured journal/thrust bearings have been the subject of several studies, including Refs. [18][19][20][21][22][23][24][25]. To the authors' knowledge, studies on the dynamic characteristics of textured thrust bearings have not yet been reported.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Stiffness and Damping in Textured Sector Pad Micro Thrust Bearings Using Computational Fluid Dynamics

Papadopoulos

Nikolakopoulos

Kaiktsis

2012

Journal of Engineering for Gas Turbines and Power

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“…Furthermore, numeroushave paid attention to the various aspects of the characteristics of hydrostatic turntable or bearing [1][2][3][4][5][6][7][8][9][10][11][12][13] .According to references review, we found the investigation of tilt effect is not sufficient. The preloaded oil pad is an important part of the supporting systemof hydrostatic turntable.…”

Section: Introductionmentioning

confidence: 99%

The study of tilt effect on the preloaded oil pad of hydrostatic turntable

Liu¹,

Li²,

Zhan³

et al. 2015

Advances in Intelligent Systems Research

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Keys: hydrostatic turntables；Reynolds equation；thermal fluid；the finite difference method； hydrostatic lubrication Abstract: A new method is proposed to analyze thebearing properties ofthe preloaded oil pad in different compensation method when the hydrostatic turntable tilts.Energy equationandReynolds equationare coupled and solved in this paper.Results show that the bearing properties of the preloaded oil pad will be significantly reduced when titling. Andload carrying capacity even decreases by 42% at maximum tilt angle. All the heat produced in the lubricant film by friction also has a significant impact on the bearingproperties of the preloaded oil pad.

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“…However, the effects on the lateral shaft vibration of hydrodynamic thrust bearing have not been investigated so extensively as those of journal bearings. The dynamic coefficients of hydrodynamic thrust bearing and the effects on axial vibration were presented by Someya and Fukuda [1], Storteig and White [2], and Zhu et al [3], and the identification of a hydrodynamic thrust bearing is discussed in reference [4,5]. Mittwollen et al [6] studied the effects of hydrodynamic thrust bearing on the lateral vibration of a rotor system.…”

Section: Introductionmentioning

confidence: 99%

Lateral Vibration of Hydroelectric Generating Set with Different Supporting Condition of Thrust Pad

Chu

2011

Shock and Vibration

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Abstract. The variations of the supporting condition, which change the stiffness of tilting pad thrust bearing, may alter the dynamic behavior of the rotor system. The effects of supporting condition of thrust pad on the lateral vibration of a hydroelectric generating set are investigated in this paper. The action of a thrust bearing is described as moments acting on the thrust collar, and the tilting stiffness coefficients of thrust bearing are calculated. A model based on typical beam finite element method is established to calculate the dynamic response, and the effects of supporting conditions such as elastic oil tank support, different heights of the thrust pads with rigid support are discussed. The results reveal that the influence of thrust bearing is small when the elastic oil tanks work normally. When the supporting conditions turn to be rigid due to the oil leakage, the differences of thrust pad heights have evident influence on the load distribution of the thrust pads; while the effects on the tilting stiffness of the thrust bearing and the amplitude of the lateral shaft vibration is small when the maximum load on thrust pads is smaller than the allowable value.

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Dynamic characteristics of hydrodynamically lubricated fixed-pad thrust bearings

Cited by 14 publications

References 6 publications

Characterization of Stiffness and Damping in Textured Sector Pad Micro Thrust Bearings Using Computational Fluid Dynamics

Characterization of Stiffness and Damping in Textured Sector Pad Micro Thrust Bearings Using Computational Fluid Dynamics

The study of tilt effect on the preloaded oil pad of hydrostatic turntable

Lateral Vibration of Hydroelectric Generating Set with Different Supporting Condition of Thrust Pad

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