Optimum Hydrodynamic Journal Bearing Performance Characteristics in High-Speed and High-Power Gearboxes

2020 ◽  
Author(s):  
Sivakumar Dakshinamurthi ◽  
Suresh Nagesh
Keyword(s):  
High Power ◽  
High Speed ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Hydrodynamic Journal Bearing

Investigation the combined effects of wear and turbulent on the performance of hydrodynamic journal bearing operating with couple stress fluids

2019 ◽  
Vol 10 (6) ◽  
pp. 825-837
Author(s):  
Mushrek A. Mahdi ◽  
Ahmed Waleed Hussein
Keyword(s):  
Couple Stress ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Turbulent Regime ◽  
Hydrodynamic Bearings ◽  
Content Type ◽  
Hydrodynamic Journal Bearing ◽  
Local Reynolds Number ◽  
Couple Stress Fluids

Purpose The purpose of this paper is to investigate the combined effect of wear and turbulence on the performance of a hydrodynamic journal bearing operating under Newtonian and couple stress fluids (CSF). Design/methodology/approach The analysis consists of a modified Reynolds equation of incompressible thin viscous films, and the film thickness model taking into account the wear effect. The governing equation was solved numerically using the finite difference approach. Findings The effect of both the wear parameter and the local Reynolds number on the performance characteristics of bearing has been presented and discussed. The obtained results observed that the characteristics of the intact and worn bearing in turbulent and laminar have been enhanced due to the non-Newtonian fluid (CSF) effect. Also, the results display that bearing worn and the turbulent regime cannot be neglected in calculating the performance characteristics of the bearing lubricated with Newtonian and non-Newtonian fluids. The results achieved from this study, specify that the bearing characteristics are significantly affected by these effects. Originality/value The paper investigates the behavior of hydrodynamic bearings considering different aspects simultaneously is interesting, and the application meets the current needs of improvement in modeling hydrodynamic bearings under different conditions.

Linear stability analysis of finite hydrodynamic journal bearing under turbulent lubrication with coupled-stress fluid

2016 ◽  
Vol 68 (3) ◽  
pp. 386-391 ◽  
Author(s):  
Abhishek Ghosh ◽  
Sisir Kumar Guha
Keyword(s):  
Stability Analysis ◽  
Newtonian Fluid ◽  
High Speed ◽  
Journal Bearing ◽  
Slenderness Ratio ◽  
Linear Perturbation ◽  
Content Type ◽  
Hydrodynamic Journal Bearing ◽  
The Stability ◽  
Coupled Stress

Purpose Several researchers have observed that to satisfy modern day’s need, it is essential to enhance the characteristics of journal bearing, which is used in numerous applications. Moreover, the use of Newtonian fluid as a lubricant is diminishing day by day, and the use of Non-Newtonian fluids is coming more into picture. Furthermore, if turbo-machinery applications are taken into account, then it can be seen that journal bearings are used for high speed applications as well. Thus, neglecting turbulent conditions may lead to erroneous results. Hence, this paper aims to present focuses on studying the stability characteristics of finite hydrodynamic journal bearing under turbulent coupled-stress lubrication. Design/methodology/approach First, the governing equation relevant to the problem is generated. Then, the dynamic analysis is carried out by linear perturbation technique, leading to three perturbed equations, which are again discretized by finite difference method. Finally, these discretized equations are solved with the help of Gauss-Seidel Iteration technique with successive over relaxation scheme. Consequently, the film response coefficients and the stability parameters are evaluated at different parametric conditions. Findings It has been concluded from the study that with increase in value of the coupled-stress parameter, the stability of the journal may increase. Whereas, with increase in Reynolds number, the stability of the journal decreases. On the other hand, stability increases with increasing values of slenderness ratio. Originality/value Researches have been performed to study the dynamic characteristics of journal bearing with non-Newtonian fluid as the lubricant. But in the class of non-Newtonian lubricants, the use of coupled-stress fluid has not yet been properly investigated. So, an attempt has been made to perform the stability analysis of bearings with coupled-stress fluid as the advanced lubricant.

Analysis and comparison of steady-state performance characteristics of two-axial groove and multilobe hydrodynamic bearings lubricated with non-Newtonian fluids

2018 ◽  
Vol 232 (12) ◽  
pp. 1581-1596 ◽  
Author(s):  
Bhrigu Jyoti Das ◽  
Lintu Roy
Keyword(s):  
Steady State ◽  
High Speed ◽  
Journal Bearing ◽  
Maximum Flow ◽  
Maximum Load ◽  
Performance Characteristics ◽  
Flow Coefficient ◽  
Rotating Speed ◽  
The Stability ◽  
Steady State Performance

Rotating machines are one of the most important and widely used machineries in the modern engineering world. They are also the required to run at high rotating speed. The plain journal bearing is mostly replaced by some other bearing, as it does not suit the stability requirement of high-speed machines and precision machine tools. In order to improve the stability of a circular bearing, many researchers tried to change its geometrical configuration. In view of this, an attempt has been made in the present work to study the performance characteristics of four different bearing configurations using non-Newtonian lubricant and comparison of the results has been made with plain journal bearing. To calculate the steady-state performance characteristics, nondimensional form of the Reynolds equation using non-Newtonian lubricant has been written and solved for the steady-state nondimensional pressure distribution in a finite grid using finite difference method with successive over-relaxation technique satisfying appropriate boundary condition. From the study, it can be concluded that three-lobe bearing have maximum load-carrying capacity and minimum friction variable, whereas two-lobe bearing have maximum flow coefficient.

Influence of dimple location and depth on the performance characteristics of the hydrodynamic journal bearing system

2020 ◽  
Vol 234 (9) ◽  
pp. 1500-1513
Author(s):  
Niranjan Singh ◽  
RK Awasthi
Keyword(s):  
Reynolds Equation ◽  
Journal Bearing ◽  
Dynamic Performance ◽  
Performance Characteristics ◽  
Eccentricity Ratio ◽  
Bearing Surface ◽  
Surface Textures ◽  
Hydrodynamic Journal Bearing ◽  
Theoretical Results ◽  
Bearing System

This paper concerns with theoretical investigation to predict the influence of cylindrical textures on the static and dynamic performance characteristics of hydrodynamic journal bearing system and the performance is compared with smooth surface bearing. The Reynolds equation governing the fluid–film between the journal and the bearing surface is solved numerically with the assistance of finite element method and the performance characteristics are evaluated as a function of eccentricity ratio, dimple depth and its location. In this study, four journal bearing configurations viz: smooth (non-textured), full-textured, partially textured-I, and partially textured-II are considered for the evaluation of theoretical results. The simulated results indicate that the influence of surface textures is more significant when the textures were created in upstream zone of 126°–286° and dimple aspect ratio nearly 1.0.

Three-dimensional computational fluid dynamic analysis of high-speed water-lubricated hydrodynamic journal bearing with groove texture considering turbulence

2021 ◽  
pp. 135065012199851
Author(s):  
Huihui Feng ◽  
Shuyun Jiang ◽  
Yanqin Shang-Guan
Keyword(s):  
Computational Fluid Dynamic ◽  
High Speed ◽  
Journal Bearing ◽  
Fluid Dynamic ◽  
Load Capacity ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Computational Fluid Dynamic Analysis ◽  
Hydrodynamic Journal Bearing ◽  
Groove Texture

Water-lubricated bearings have attracted increasing attention in the field of high-speed machine tools for their low friction due to low viscosity. However, new problems, in particular, insufficient load capacity, are on the way. To the point, groove-textured journal bearing is adopted in this study. Aiming at investigating the effects of groove texture on high speed, water-lubricated, hydrodynamic journal bearing precisely, and thoroughly, three-dimensional computational fluid dynamic analyses considering cavitation and turbulence are undertaken to assess the tribological performances of the bearing. To reduce the amount of three-dimensional modeling and meshing work, mesh deformation is presented. The numerical results are compared with experiments to verify the validity of the present models and calculation procedures. Pressure distribution, load capacity, and friction of groove-textured water-lubricated journal bearing are analyzed with respect to operating conditions and geometric parameters. Comparisons between groove-textured water-lubricated journal bearing and smooth bearing are carried out to find out the influence of groove texture. It is found that the groove texture can achieve a remarkable improvement of load capacity at a smaller eccentricity ratio and higher rotary speed. The load capacity is affected by the combined effects of groove depth, width, and length. However, generally, the friction force of water-lubricated journal bearing is slightly influenced by groove texture. Results can provide theoretical guidance for the optimal design of groove-textured water-lubricated journal bearing under different operating parameters.

Performance of Two Lobe Multirecess Hybrid Journal Bearing Compensated With Capillary Restrictor

2007 ◽  
Author(s):  
Prashant Kushare ◽  
Satish C. Sharma ◽  
S. C. Jain ◽  
J. Sharana Basavaraja
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Dynamic Performance ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Favourable Effect ◽  
Improved Performance ◽  
Stiffness And Damping ◽  
Offset Factor ◽  
Bearing System

Multirecess hydrostatic/hybrid journal bearings are being used in many applications owing to their excellent characteristics. The Noncircular journal bearing configurations too are quite frequently used in high speed machinery as they are efficient, less costly and provide better shaft stability. The Two lobe bearing (elliptical bearing) are among the commonly used noncircular journal bearing configuration. The multilobe multirecess hybrid journal bearings have been developed to combine the features of noncircular and circular hybrid journal bearing configurations. In the present work a theoretical investigation of a two lobe multirecess hydrostatic/hybrid journal bearing system have been carried out. The multilobe journal bearing configuration is designed as an arc of the circle with the centre points placed on the symmetry line of the single lobe. The journal offset has been accounted by defining an offset factor ‘δ’. The finite element method has been used to solve the Reynolds equation governing the flow of lubricant in the clearance space of the journal bearing system. The bearing static and dynamic performance characteristics have been presented for the various values of the offset factors (0.75, 1, 1.25 and 1.50) for hybrid mode of operation of the bearing. The simulated results of the studies reveals that, a two lobe recessed hybrid journal bearing provides an improved performance in respect of fluid film stiffness and damping coefficients as compared to that of circular recessed journal bearing. It has been observed that for a multilobe bearing having offset factor more than one has a favourable effect on the dynamic performance characteristics of the two lobe bearing.

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