Effect of the axial movement of misaligned journal on the performance of hydrodynamic lubrication journal bearing with rough surface

The marine stern bearing provides supporting force by lubricating film to minimise the contact friction with the propeller shaft. A model considers local wear and asperity contact is proposed to investigate the mixed lubrication of bearing with misalignment. The finite difference method and over‐relaxation iteration method are employed to solve the average Reynolds equation. The lubrication behaviour includes hydrodynamic pressure, film thickness, contact force and friction coefficient were calculated. The influence of sliding speed, local wear, contact roughness, misalignment angle, elastic deformation and eccentricity ratio is discussed in detail. The critical speed from mixed lubrication to fluid lubrication is obtained by employing the Stribeck curve. Moreover, the dimensionless average hydrodynamic pressure, film thickness and the peak value of contact force are compared.

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“…The load capacity F and bearing angle

ϕ

24 are given as follows:

\begin{matrix} F goodbreak= \sqrt{F_{x}^{2} + F_{y}^{2}}, \\ ϕ goodbreak= ((), 1 goodbreak- {signF}_{y}) \cdot 90^{\circ} goodbreak+ {signF}_{y} \cdot {signF}_{x} \cdot ϕ^{'} . \end{matrix}

…”

Section: Equation Of Motionmentioning

confidence: 99%

The influence of local wear and contact roughness on mixed lubrication of marine stern bearing with misaligned shaft

Zhao

Huang

Sheng

2023

Lubrication Science

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“…Belkacem et al 3 investigated the effect of bearing surface microtexture and journal tilt angle on the performance of hydrodynamic journal bearing using the finite difference method, the results showed that the correct alignment of texture at high eccentricity and tilt angle had a great impact on the performance of tilt journal bearings. Li et al 4 investigated the effect of journal axial motion on the lubrication characteristics of tilt journal bearings, and revealed that the greater the tilt angle of journal, the greater the effect of the journal axial speed. Girish et al 5 proposed an innovative form of four‐tile variable bearing structure considering journal tilt.…”

Section: Introductionmentioning

confidence: 99%

Study on the influence of journal form and position errors on the lubrication performance of four‐recess capillary restrictor hybrid journal bearing

Wang

Duan

et al. 2023

Lubrication Science

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In the actual working condition, due to the manufacturing errors, improper installation, load, thermal deformation or other factors can cause the journal surface to produce the form and position errors. The mathematical models are developed that takes into account the form and position errors, the lubrication performance of four-recess capillary restrictor hybrid journal bearings with different journal tilt angles and cylindricities is studied, and the effect of eccentricity on the oil film lubrication performance is analysed. The results show that the dimensionless oil film pressure and loading capacity increase as the journal tilt angle and eccentricity increase considering journal tilt, and the friction coefficient tends to increase and then decrease. Compared with journal alignment, the oil film thickness distorts, the oil film pressure peak shifts to the edge of bearing, and the horizontal tilt has a greater impact on bearing when the journal is tilted. The oil film pressure distribution has no significant change considering cylindricity errors, while the oil film pressure value increases, the loading capacity increases and the coefficient of friction decreases as the cylindricity and eccentricity increase. The research shows that the presence of a certain cylindricity error contributes to the lubrication performance of four-recess capillary restrictor hybrid journal bearings.

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“…The linear [15] and nonlinear [16][17][18] effects on the bearing characteristics caused by rotor disturbances were also researched. The axial motion [19][20][21] was also taken into consideration. The effects of misalignment of the rotor-bearing system on the fault diagnosis was also a hot topic [22,23].…”

Section: Introductionmentioning

confidence: 99%

Model and Algorithm for a Rotor-Bearing System Considering Journal Misalignment

Zhao,

Ma,

Liu

et al. 2023

Coatings

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Disturbances caused as a result of the misalignment and axial motion of the journal affect the characteristics of the rotor-bearing system. This paper aims to propose an algorithm for the theoretical analysis of a rotor-bearing system that considers these disturbances. A theoretical model for a journal bearing considering disturbances is given. The dynamic equations for a rigid rotor-bearing system are introduced. A detailed algorithm that can simultaneously solve the rotor-dynamic equations and the Reynolds equation is proposed. The static performance, such as the bearing attitude angle and the fluid film pressure, are given, and dynamic characteristics such as the nonlinear dynamic responses and the axial orbits of a rigid rotor-bearing system are presented. The hydrodynamic effect of the bearing is enhanced by the axial disturbance. Disturbances in the circumferential and radial directions lead to variations in the fluid film thickness distribution in the axial direction and the offset of the fluid film pressure distribution in the axial direction. When these disturbances work together, the variation trend is more obvious and affects the capacity and dynamic characteristics of the bearing. When the L/D value of the bearing increases, the clearance between the journal and the bearing decreases rapidly. When the value reaches a certain limit, contact and collision might occur. The theoretical analysis method and the algorithm proposed for a rotor-bearing system considering several disturbances could enhance the design level for a bearing and rotor-bearing system.

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Effect of the axial movement of misaligned journal on the performance of hydrodynamic lubrication journal bearing with rough surface

Cited by 8 publications

References 24 publications

The influence of local wear and contact roughness on mixed lubrication of marine stern bearing with misaligned shaft

The influence of local wear and contact roughness on mixed lubrication of marine stern bearing with misaligned shaft

Study on the influence of journal form and position errors on the lubrication performance of four‐recess capillary restrictor hybrid journal bearing

Model and Algorithm for a Rotor-Bearing System Considering Journal Misalignment

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