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.

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.

Temperature rise of journal bearing of the high-speed circular arc gear pump

2019 ◽  
Vol 234 (8) ◽  
pp. 1492-1499
Author(s):  
Yang Zhou ◽  
Yuan Ci
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Journal Bearing ◽  
Radial Force ◽  
Calculation Model ◽  
Journal Bearings ◽  
Gear Pump ◽  
Accurate Calculation ◽  
Circular Arc ◽  
Herringbone Grooves

A “circular arc–involute–circular arc” circular arc gear pump was developed based on a gear meshing principle and coordinate transformation as well as an accurate calculation model of the radial force. The dependence of the radial force on the meshing angle was investigated. The temperature rise of journal bearings in the pump was evaluated for bearings with and without herringbone grooves. Furthermore, the influence of the rotational speed and outlet pressure on this rise was assessed. The results revealed using herringbone groove on the inner wall of bearing was effective in reducing the temperature increase. Therefore, the use of grooves represents a suitable method of reducing the temperature rise in the journal bearings of a high-speed gear pump.

Performance Characteristics of Two-Lobe Hydrodynamic Journal Bearings

1980 ◽  
Vol 102 (4) ◽  
pp. 425-429 ◽  
Author(s):  
Ashok Kumar ◽  
R. Sinhasan ◽  
D. V. Singh
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Design Data ◽  
Detailed Design ◽  
Flow Friction ◽  
Damping Coefficients ◽  
Stiffness And Damping ◽  
Film Stiffness

The performance characteristics of noncircular bearings are known to be superior to those of the circular bearings. The two lobe bearings are finding increasing application in high speed turbomachinery. Using a variational solution, detailed design data have been computed for two-lobe bearings in this paper. The data include Sommerfeld number, equilibrium locus, fluid film stiffness and damping coefficients, end-flow, friction parameter, and temperature rise parameter.

Analysis of Thermal Properties of Super-High Speed Hybrid Journal Bearing Based on ANSYS

2010 ◽  
Vol 118-120 ◽  
pp. 753-757 ◽  
Author(s):  
Shi Chao Xiu ◽  
Shi Qiang Gao ◽  
Zhi Li Sun
Keyword(s):  
Thermal Properties ◽  
Temperature Rise ◽  
High Speed ◽  
Journal Bearing ◽  
Journal Bearings ◽  
Main Shaft ◽  
Temperature Field Distribution ◽  
Shaft System ◽  
The Mathematical Model ◽  
Heat Mechanism

Hybrid journal bearings are used in the high and super high speed cases mainly, such as the super-high speed spindle system. Since the bearing operates under high speed conditions, the excessive temperature rise of the bearing is a major reason to lower the accuracy of the main shaft system and limit the bearings working speed higher, as a result, restrict the bearing applications. In this paper, the thermal properties and the heat mechanism of such bearings are analyzed. The mathematical model of hybrid journal bearing is established to analyze the mechanism of generating heat. In addition, the temperature field distribution for the certain hybrid journal bearing at speed of 10000 rpm is studied by means of software ANSYS considering the heat transfer characters between fluid and solid. An improved measure about temperature rise of hybrid journal bearing is presented.

Comparison of static performance characteristics of different configurations of slot-entry hybrid journal bearing operating with non-Newtonian lubricants

2014 ◽  
Vol 66 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Hem Chander Garg ◽  
Vijay Kumar
Keyword(s):  
Journal Bearing ◽  
Research Work ◽  
Flow Equation ◽  
Journal Bearings ◽  
Performance Characteristics ◽  
Content Type ◽  
Wide Range ◽  
Static Performance ◽  
Fluid Film Thickness ◽  
Newtonian Behavior

Purpose – The slot-entry hybrid journal bearings have been successfully used in various engineering applications because of their good performance over wide range of speed and load, besides their relative simplicity in manufacturing. Most of the research work pertaining to non-recessed journal bearing assumes standard symmetric and asymmetric configurations. However, many more configurations are possible by changing the position of slot which may improve the performance of the slot-entry journal bearing. In the present work study of static performance characteristics of slot-entry journal bearing of different configuration has been carried out. The paper aims to discuss these issues. Design/methodology/approach – FEM has been used to solve the Reynolds equation governing the flow of lubricant in the bearing clearance space along with the restrictor flow equation. The non-Newtonian lubricant has been assumed to follow the cubic shear stress law. The performance characteristics of slot-entry hybrid journal bearings are computed by developing a computer program. Findings – The simulated results of bearing characteristics parameters in terms of minimum fluid-film thickness and bearing flow have been presented for the wide range of various values of non-linearity factor and external load. It is found that there is an increase in the oil requirement for slot-entry hybrid journal bearing with the specified operating and geometric parameters, when the viscosity of the lubricant decreases due to the non-Newtonian behavior of the lubricant. The effect of the decrease in the viscosity of the lubricant due to non-Newtonian behavior of the lubricant diminishes the attitude angle. The computed performance characteristics are helpful for the bearing designer while choosing a particular configuration of bearing. Research limitations/implications – The performance characteristics have been computed by considering the non-Newtonian lubricants. The thermal effects have been ignored in the analysis so as to obviate the mathematical complexity. Originality/value – Get idea from already published manuscripts.

Effect of recess configuration on the performances of high-speed hybrid journal bearing

2016 ◽  
Vol 68 (3) ◽  
pp. 301-307 ◽  
Author(s):  
Qiyin Lin ◽  
Zhengying Wei ◽  
Ning Wang ◽  
Yubin Zhang
Keyword(s):  
Temperature Rise ◽  
High Speed ◽  
Design Methodology ◽  
High Stability ◽  
Journal Bearing ◽  
Content Type ◽  
Structure Interaction ◽  
Bearing Design ◽  
Effects Of Temperature ◽  
Interaction Approach

Purpose The purpose of this paper is to study the influences of recess configurations on the performances of high-speed hybrid journal bearing. Hybrid journal bearing earns increasing attention in high-speed machine tool spindle owing to its intrinsic outstanding performances of low temperature rise and high stability. Design/methodology/approach To investigate the coupled effects of temperature, turbulence and the interaction between lubricant and journal/bearing bush, a thermal fluid-structure interaction approach is presented and validated by the experimental results. Findings Ladder-type recess has excellent tribological characteristics in decreasing temperature rise, improving stability and inhibiting cavitation, which are all beneficial to improve the performances of high-speed spindle system. Originality/value This work can be a valuable guide for the future high-speed hybrid journal bearing design.

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