Restrictor-based studies of hybrid hole-entry conical journal bearings

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Prashant G. Khakse ◽  
Vikas M. Phalle
Keyword(s):  
Numerical Simulation ◽  
Design Methodology ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Constant Flow ◽  
Hybrid Mode ◽  
Content Type ◽  
Conical Bearing ◽  
Flow Valve

Purpose This paper aims to describe how successfully a particular restrictor delivers its best in increasing the conical journal bearing performance. The restrictors are used in the hole-entry conical journal bearing subjected to hybrid mode. Thus, the restrictors, like constant flow valve (CFV), orifice and capillary, are studied comparatively. Design/methodology/approach Numerical simulation for the bearing results with the three restrictors are obtained by using finite element method (FEM) under the well-known modified Reynolds equation. Findings When the hole-entry conical journal bearings, with the restrictor design parameter range C¯s2 = 0.03 – 0.09, are operated, the results obtained are quite distinctive and significant. It indicates that the CFV restrictor-based conical bearing gives enhanced performance in comparison to orifice and capillary restrictors. Moreover, it suggests the performance-wise sequence of the restrictors in hybrid bearings as CFV > Orifice > Capillary. Originality/value The outcome of the research paper will give insight to help the bearing designer to choose the particular restrictor in hybrid conical bearing depending on the industrial need.

Analysis of Multirecess Hydrostatic Journal Bearing Operating With Micropolar Lubricant

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Suresh Verma ◽  
Vijay Kumar ◽  
K. D. Gupta
Keyword(s):  
Reynolds Equation ◽  
Theoretical Study ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Constant Flow ◽  
The Finite Element Method ◽  
Lubricant Flow ◽  
Wide Range ◽  
Flow Valve

This paper presents a theoretical study of the performance characteristics of a constant flow valve compensated multirecess hydrostatic journal bearings operating with micropolar lubricant. The finite element method and iterative procedure have been used to solve the modified Reynolds equation governing the micropolar lubricant flow in the bearing. The performance characteristics are presented for a wide range of nondimensional load, lubricant flow, and micropolar parameters. It has been observed that the micropolar parameters significantly influence the performance characteristics of the bearing.

Thermohydrostatic rheological analysis of constant flow valve compensated multiple hole-entry hybrid journal bearings

2014 ◽  
Vol 66 (2) ◽  
pp. 244-259 ◽  
Author(s):  
H.C. Garg ◽  
Vijay Kumar
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Constant Flow ◽  
Design Data ◽  
Content Type ◽  
Viscosity Variation ◽  
Flow Valve ◽  
Newtonian Behavior

Purpose – The changing technological scenario necessitated hybrid journal bearings to operate under severe conditions of heavy load and high speed resulting into temperature rise of the lubricant fluid-film and bearing surface. To predict the performance of a bearing realistically, theoretical model must consider the combined influence of the rise of temperature and non-Newtonian behavior of the lubricant. The aim of the present paper is to study the effect of viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on performance of constant flow valve compensated multiple hole-entry hybrid journal bearings. Design/methodology/approach – Finite element method has been used to solve Reynolds equation along with restrictor flow equation, 3D energy equation and 3D conduction equation using suitable iterative technique. The non-Newtonian lubricant has been assumed to follow cubic shear stress law. Findings – The thermohydrostatic rheological performances of symmetric and asymmetric hole-entry hybrid journal bearing configurations are studied. The computed results illustrate that variation of viscosity due to rise in temperature and non-Newtonian behavior of the lubricant affects the performance of hole-entry hybrid journal bearing system quite significantly. Originality/value – In the present work, the influences of the viscosity variation due to temperature rise and non-Newtonian behavior of the lubricant on the performance characteristics of non-recessed hole-entry hybrid journal bearing with symmetric and asymmetric configurations compensated with constant flow valve restrictors have been investigated for generating the design data to be used by bearing designer. The design data computed in the present thesis are a contribution in field of knowledge of bearing design.

A Comparative Thermal Analysis of Slot-Entry and Hole-Entry Hybrid Journal Bearings Lubricated With Non-Newtonian Lubricant

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
H. C. Garg ◽  
Vijay Kumar ◽  
H. B. Sharda
Keyword(s):  
Reynolds Equation ◽  
Energy Equation ◽  
Journal Bearing ◽  
Flow Equation ◽  
Journal Bearings ◽  
Constant Flow ◽  
Viscosity Variation ◽  
Bearing System ◽  
Flow Valve ◽  
Newtonian Behavior

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.

Effect of micropolar lubrication in non-circular hole-entry hybrid journal bearing with constant flow valve restrictor

2016 ◽  
Vol 68 (6) ◽  
pp. 737-751 ◽  
Author(s):  
Rajneesh Kumar ◽  
Suresh Verma
Keyword(s):  
Circular Hole ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Constant Flow ◽  
Content Type ◽  
Micro Particles ◽  
Research Gap ◽  
Offset Factor ◽  
Flow Valve

Purpose In the present scenario of high-speed machines, the use of non-circular hole-entry bearing configuration, i.e. two-lobe, multi-lobe, lemon bore, etc., has becomes unavoidable, as the journal bearings with non-circular configurations provide better stability at high operating speed and heavy dynamic loading. Further, this research aims to show that the presence of micro particles in the lubricants greatly affects performance of the bearings, as their presence leads to non-Newtonian behaviors of the lubricant. Therefore, to consider the effect of these micro particles, the lubricant is modeled as a micropolar lubricant. The present work analyzes the effect of these micropolar lubricants on the performance of hole-entry circular and non-circular (two-lobe) hybrid journal bearings compensated with constant flow valve restrictor and compares with that of Newtonian lubricants. Design/methodology/approach The modified Reynolds equation governing the laminar flow of iso-viscous, incompressible micropolar lubricant in the clearance space of a journal bearing system has been solved using finite element method and appropriate boundary conditions. Further, a comparative analysis between circular and non-circular (two-lobe) hybrid journal bearing compensated with constant flow valve restrictor operating with Newtonian and micropolar lubricant has been presented. Findings The numerically simulated results reveal that the non-circular bearing configuration provides better performance vis-à-vis the circular bearing configuration. Further, the increase in the micropolar effect of the lubricant enhances the performance of circular and the non-circular bearing configurations compared with the Newtonian lubricant. Also, in the case of the non-circular bearing configuration with an offset factor (δ = 1.5), the bearing performance improved compared with (δ = 1.25). Originality/value Many research studies have been done in the area of non-circular hybrid journal bearing with Newtonian lubricants with different types of restrictors, but the non-circular hole-entry constant flow valve-compensated hybrid journal bearing operating with the micropolar lubricant has not been analyzed. Therefore, in the present work, an effort has been made to fill this research gap.

Performance comparison of hole-entry and slot entry hybrid journal bearings considering combined influence of thermal effects and micropolar lubricant

2018 ◽  
Vol 70 (6) ◽  
pp. 1037-1050 ◽  
Author(s):  
Pankaj Khatak ◽  
H.C. Garg
Keyword(s):  
Thermal Effects ◽  
Temperature Increase ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Constant Flow ◽  
Viscosity Change ◽  
Efficient Operation ◽  
Content Type ◽  
Wide Range ◽  
Flow Valve

Purpose Hybrid journal bearing have long been used in machines requiring large load and high speed capacity operating under wide range of temperatures. Different compensating devices are used in for efficient operation of bearings. This paper aims to help in selection of optimum compensating device by evaluating the comparative performance of constant flow valve, capillary compensated and slot entry hybrid journal bearing under the combined influence of thermal effects and micropolar nature of lubricant. Design/methodology/approach The variation in micropolar parameters and viscosity change due to temperature increase of lubricant are considered in present study. Finite element method is used for combined iterative solution of micropolar Reynolds, energy and conduction equations. Micropolar lubricant is assumed to be governed by two parameters, coupling number and characteristic length. The results in the study are presented for symmetric and asymmetric configurations of hole entry and slot entry non-recessed hybrid journal bearings Findings The results indicate that constant flow valve compensated hole entry hybrid journal bearing is the highest performing bearing for the given range of micropolar parameters of lubricant in terms of maximum fluid pressure and dynamic coefficients. Originality/value The performance variations of various configurations of hybrid journal bearing are presented in a single paper. The reader can get overview of combined effects of micropolar parameters and viscosity decrease due to temperature increase of the lubricant.

scholarly journals Analytical Study of Non-Recessed Conical Hole Entry Hybrid/Hydrostatic Journal Bearing with Constant Flow Valve Restrictor

2020 ◽  
Vol 37 (3−4) ◽  
Author(s):  
Prashant Govindrao Khakse ◽  
Vikas M. Phalle
Keyword(s):  
Journal Bearing ◽  
Angular Distance ◽  
Maximum Pressure ◽  
Constant Flow ◽  
Double Row ◽  
Element Analysis ◽  
Load Carrying ◽  
Conical Bearing ◽  
Film Stiffness ◽  
Flow Valve

The present work studies the analysis of a non recessed hole entry conical hybrid/hydrostatic journal bearing adjusted for constant flow valve (CFV) restriction. The paper provides effectiveness between the conical bearings with hole entry operating in hybrid and hydrostatic mode. The Reynolds formulae, for the flow of fluid through the mating surfaces of a conical journal and bearing, are numerically worked out in both the modes considering the finite element analysis (FEA) and the necessary boundary preconditions. Holes in double row are marked on conical bearing circumference to accommodate the CFV restrictors, the angular distance between two holes are 30o apart from the apex. Qualitative features of the conical journal bearing system with hole entry have been elaborated to analyze bearing performance for radial load variation Wr = 0.25-2. Numerical results obtained from the present study indicate that load carrying capacity of conical bearing, operating in hydrostatic mode, is enhanced by the maximum pressure, direct fluid film damping and direct film stiffness coefficients vis-a-vis corresponding hybrid mode.  

Behaviour of two-lobe hole-entry hybrid journal bearing system under the combined influence of textured surface and micropolar lubricant

2017 ◽  
Vol 69 (6) ◽  
pp. 844-862 ◽  
Author(s):  
Chandra B. Khatri ◽  
Satish C. Sharma
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Numerical Technique ◽  
Surface Texturing ◽  
Textured Surface ◽  
Performance Parameters ◽  
Content Type ◽  
Fluid Theory ◽  
Bearing System

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.

scholarly journals A Comparative Elastohydrostatic Analysis of CFV- and Capillary-Compensated Multirecess Hydrostatic/Hybrid Journal Bearing Operating with Micropolar Lubricant

2013 ◽  
Vol 2013 ◽  
pp. 1-17 ◽  
Author(s):  
Suresh Verma ◽  
Vijay Kumar ◽  
K. D. Gupta
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Comparative Study ◽  
Elastic Deformation ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Performance Characteristics ◽  
Constant Flow ◽  
Bearing System ◽  
Flow Valve

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.

Effect of wear on the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation

2019 ◽  
Vol 233 (9) ◽  
pp. 1277-1292 ◽  
Author(s):  
Sanjay R Pawar ◽  
Vikas M Phalle
Keyword(s):  
Film Thickness ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Load Capacity ◽  
Radial Clearance ◽  
Constant Flow ◽  
Performance Parameters ◽  
Element Analysis ◽  
Spherical Coordinate ◽  
Flow Valve

Hybrid bearings gets worn gradually during the start and stop operation. This wearing leads to change in the geometry of bearing and affects the radical clearance as well as fluid film thickness. Therefore, these discontinuities in the radial clearance can influence the performance characteristics. With the purpose of preventing irreparable failure state of bearing assembly, it is essential to concentrate on the actual changes in the performance parameters of hole entry hybrid conical journal bearing due to wear. In this context, the main aim of this analysis is to predict the performance of hole entry hybrid conical journal bearing employing constant flow valve compensation. Modified Reynolds equation in spherical coordinate form is used to govern the flow of lubricant in the narrow region between journal and conical bearing. The solution to this Reynolds equation is obtained by finite element analysis with appropriate boundary conditions. This paper summarizes that for a given bearing with constant flow valve as compensating element, the wear causes variation in lubricant film thickness, which strongly affects load capacity, pressure generated, and dynamic performance parameters.

Relationship between elliptical form error and rotation accuracy of hydrostatic journal bearing

2017 ◽  
Vol 69 (6) ◽  
pp. 905-911 ◽  
Author(s):  
Jun Zha ◽  
Yaolong Chen ◽  
Penghai Zhang
Keyword(s):  
Kinetic Equation ◽  
Continuity Equation ◽  
Reynolds Equation ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Form Error ◽  
Machining Error ◽  
Content Type ◽  
Precision Design ◽  
Error Averaging

Purpose The form error of shaft and hole parts is inevitable because of the machining error caused by rotation error of tool axis in machine tools where the elliptical form error is the most common in shaft and bearing bush. The purpose of this paper is to present the relationship between the elliptical form error and rotation accuracy for hydrostatic journal bearing in precision spindle and rotation table. Design/methodology/approach An error averaging effect model of hydrostatic journal bearing is established by using Reynolds equation, pressure boundary conditions, flux continuity equation of the land and kinetic equation of shaft in hydrostatic journal bearing. The effects of shaft and bearing bush on rotation accuracy were analyzed quantitatively. Findings The results reveal that the effect of shaft elliptical form error on rotation accuracy was six times larger than bearing bush. Therefore, to improve the rotation accuracy of hydrostatic journal bearing in spindle or rotation table, the machining error of shaft should be controlled carefully. Originality/value An error averaging model is proposed to evaluate the effect of an elliptical form error on rotation accuracy of hydrostatic journal bearings, which solves the Reynolds equation, the flux continuity equation and the kinetic equation. The determination of form error parameters of shaft and bearing bush can be yielded from finding results of this study for precision design of hydrostatic journal bearings.

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