A Study of Misaligned Micropolar Lubricated Membrane Compensated Hybrid Journal Bearing System

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Satish C. Sharma ◽  
E. Rajasekhar Nicodemus ◽  
Nathi Ram

The present work aims to analytically study the performance of misaligned four-pocket, membrane compensated, hybrid journal bearing system operating with micropolar lubricant. In the present study, the flow characteristic of the lubricating oil containing additives and contaminants has been modeled using Erigen’s micropolar theory. The journal misalignment which may occur as a result of noncentral loading, improper assembly, shaft deflection due to elasticity and thermal distortions, etc. has been accounted for in the present study by defining a pair of misalignment parameters in vertical and horizontal directions (i.e., δ and σ).The modified Reynolds equation governing the flow of micropolar lubricant in the clearance space of a misaligned bearing has been solved using FEM and Newton Raphson method along with the appropriate boundary conditions. The numerically simulated results suggest that the effect of journal misalignment is to cause degradation in bearing performance, whereas the influence of micropolar effect of lubricant is to enhance the bearing performance. Therefore, it is imperative to account for the effect of misalignment and lubricant behavior during the design process in order to generate accurate bearing characteristics data.

2020 ◽  
Vol 21 (3) ◽  
pp. 301
Author(s):  
Chongpei Liu ◽  
Wanyou Li ◽  
Xiqun Lu ◽  
Bin Zhao

The textures on the bushing surface have important effects on the performance of journal bearing. In this study, the effects of double parabolic profiles with groove textures on the hydrodynamic lubrication performance of journal bearing under steady operating conditions are investigated theoretically. The journal misalignment, asperity contact and thermal effects are considered, while the profile modifications due to running-in are neglected. The Winkler/Column model is used to calculate the elastic deformation of bushing surface and the adiabatic flow hypothesis is adopted to obtain the effective temperature of lubricating oil. The numerical solution is established by using finite difference and overrelaxation iterative methods, and the rupture zone of oil film is determined by Reynolds boundary conditions. The numerical results reveal that the double parabolic profiles with groove textures with proper location and geometric sizes can increase load carrying capacity and reduce friction loss under steady operating conditions, which effectively overcome the drawbacks of double parabolic profiles. This novel bushing profile may help to reduce the bushing edge wear and enhance the lubrication performance of journal bearing.


Author(s):  
Abhishake Chaudhary ◽  
Arvind K Rajput ◽  
Rajiv Verma

This article examines the effect of couple stress lubricant on the characteristics of six-pocket hybrid irregular journal bearing system. Various shapes of irregular journals viz. barrel, bell-mouth, and undulated journal are considered in the analysis. To model the behavior of the flow of couple stress lubricant in bearing clearance space, the modified form of Reynolds equation is derived by using Stokes theory. The unknown pressure field in Reynolds equation is determined by using Galerkin's method. To illustrate the effect of couple stress lubricant on bearing system, the results for characteristics parameters of journal bearing system are presented. The results noticeably reveal that the presence of different geometrical irregularities in journal may ominously influence the performance of bearing system. Further, the use of couple stress lubricant instead of Newtonian lubricant offers a significant improvement in the value of bearing characteristic parameters of geometrically irregular hybrid journal bearing system viz. [Formula: see text], [Formula: see text] and [Formula: see text].


2017 ◽  
Vol 69 (6) ◽  
pp. 844-862 ◽  
Author(s):  
Chandra B. Khatri ◽  
Satish C. Sharma

Purpose The aim of the present paper is to study the combined influence of textured surface and micropolar lubricant behaviour on the performance of two-lobe hole-entry hybrid journal bearing system. The bearing performance parameters of the textured circular/two-lobe hole-entry hybrid journal bearing system have been computed against the constant vertical external load supported by the bearing. Design/methodology/approach In this work, Eringen’s micropolar fluid theory has been used to derive the governing Reynolds equation. The consequent solution of the governing Reynolds equation has been obtained by using finite element method (FEM) numerical technique. Findings The present study indicates that the use of the textured surface, two-lobe profile of bearing and micropolar lubricant, significantly enhances the bearing performance as compared to non-textured circular journal bearing. Originality/value The present study concerning the influence of surface texturing on the behaviour of the two-lobe hole-entry hybrid journal bearing lubricated with micropolar lubricant is original. The theoretically simulated results of the present study will be useful to design an efficient journal bearing system.


2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
J. Sharana Basavaraja ◽  
Satish C. Sharma ◽  
S. C. Jain

The work presented in this paper aims to study the performance of a two-lobe hole-entry hybrid journal bearing system compensated by orifice restrictors. The Reynolds equation governing the flow of lubricant in the clearance space between the journal and bearing together with the equation of flow through an orifice restrictor has been solved using FEM and Galerkin's method. The bearing performance characteristics results have been simulated for an orifice compensated nonrecessed two-lobe hole-entry hybrid journal bearing symmetric configuration for the various values of offset factor , restrictor design parameter , and the value of external load . Further, a comparative study of the performance of a two-lobe hole-entry hybrid journal bearing system with a circular hole-entry symmetric hybrid journal bearing system has also been carried out so that a designer has a better flexibility in choosing a suitable bearing configuration. The simulated numerical results indicate that for the two-lobe symmetric hole-entry hybrid journal bearing system with an offset factor greater than one provides 30 to 50 percent larger values of direct stiffness and direct damping coefficients as compared to a circular symmetric hole-entry hybrid journal bearing system.


2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Suresh Verma ◽  
Vijay Kumar ◽  
K. D. Gupta

A comparative study on the performance characteristics of the flexible multirecess hydrostatic journal bearing system with constant flow valve and capillary restrictors has been presented considering the effect of micropolar parameters. The modified Reynolds equation for the flow of micropolar lubricant through the bearing has been solved using finite element method, and the resulting elastic deformation in the bearing shell has been determined iteratively. The results indicate that the micropolar parameters of the lubricant affect the performance of the flexible multirecess hydrostatic journal bearing system quite significantly.


2012 ◽  
Vol 246-247 ◽  
pp. 790-794
Author(s):  
Kang Shao ◽  
Chang Wen Liu ◽  
Feng Rong Bi ◽  
Xia Wang ◽  
Jian Zhang

On the base of Reynolds equation, the dynamic load of an engine crankshaft main journal bearing system is studied. The oil film pressure is solved from the non-Newtonian Reynolds equation with non-linear model of a finite length journal bearing. The flexible crankshaft is coupling with hydrodynamic lubrication of bearing film. The elastohydrodynamic bearing is treated as non-linear bearing with the finite difference method when considered the unstability load that was acted on the main journal. This paper aims to identify the non-linear effect of engine main bearing in the case of unstability load.


Author(s):  
Prashant G Khakse ◽  
Vikas M Phalle ◽  
SS Mantha

Influence of semi-cone angles on the performance of the non-recessed hybrid/hydrostatic hole-entry conical journal bearing compensated with orifice restrictor has been carried out analytically. The analysis comprises two rows of symmetric hole-entry contour in the circumferential direction of hybrid/hydrostatic conical journal bearing. An orifice restrictor is used in the hole-entry contour to allow the restricted flow in the clearance space of a journal and bearing. Well-known finite element method and Newton–Raphson method for restrictor have been used to solve the Reynolds equation, governing the fluid flow in the clearance space of a hybrid/hydrostatic conical journal and bearing. Further, the spherical coordinate system has been employed to solve Reynolds equation instead of cylindrical coordinate system. Performance characteristics in terms of stiffness coefficient, damping coefficient, bearing pressure, bearing flow, and minimum fluid film thickness have been discussed for variable external radial load ([Formula: see text]) = 0.25–1.5. The performance characteristics in terms of [Formula: see text], [Formula: see text], and [Formula: see text] is found to be quite significant for hybrid hole-entry conical journal bearing when compared with hydrostatic hole-entry conical journal bearing, which allows the designer to choose appropriate non-recessed hybrid hole-entry conical journal bearing.


2010 ◽  
Vol 132 (4) ◽  
Author(s):  
H. C. Garg ◽  
Vijay Kumar ◽  
H. B. Sharda

The effect of viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on the performance of hole-entry and slot-entry hybrid journal bearings system is the focus of this investigation. The performance characteristics of nonrecessed hybrid journal bearings operating with different flow controlling devices, i.e., constant flow valve, capillary, orifice, and slot restrictors, have been compared. Finite element method has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation, energy equation and conduction equation using suitable iterative technique. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The results indicate that variation in viscosity due to rise in temperature and non-Newtonian behavior of the lubricant affects the performance of nonrecessed hybrid journal bearing system quite significantly. The results further indicate that bearing performance can be improved by selecting a particular bearing configuration in conjunction with a suitable compensating device.


2019 ◽  
Vol 20 (4) ◽  
pp. 402 ◽  
Author(s):  
Biao Li ◽  
Jun Sun ◽  
Shaoyu Zhu ◽  
Yangyang Fu ◽  
Xiaoyong Zhao ◽  
...  

Generally, the movement of journal along the direction of bearing axis under the combined action of various factors is neglected in the lubrication study of bearing, which is quite different from the actual working condition of bearing in the shaft-bearing system. In this paper, with a comprehensive consideration of the axial movement of journal, the surface topography of journal and bearing and the misalignment of journal, a new model about the hydrodynamic lubrication of misaligned journal bearing is established based on the average Reynolds equation. Considering the effect of the axial movement of misaligned journal, the lubrication characteristics parameters of rough journal bearing is presented and mainly discussed. The results show that the axial movement of misaligned journal has a distinct effect on the bearing lubrication characteristics. The influence of the axial movement of misaligned journal on the bearing lubrication characteristics is slightly reduced when considering the surface roughness.


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