Effect of partial grooving on the performance of hydrodynamic journal bearing

2017 ◽  
Vol 69 (4) ◽  
pp. 574-584 ◽  
Author(s):  
Anil B. Shinde ◽  
Prashant M. Pawar
Keyword(s):  
Carrying Capacity ◽  
Power Loss ◽  
Journal Bearing ◽  
Fluid Film ◽  
Frictional Torque ◽  
Load Carrying Capacity ◽  
Bearing Surface ◽  
Film Pressure ◽  
Content Type ◽  
Load Carrying

Purpose This study aims to improve the performance of hydrodynamic journal bearings through partial grooving on the bearing surface. Design/methodology/approach Bearing performance analysis is numerically carried out using the thin film flow physics of COMSOL Multiphysics 5.0 software. Initially, the static performance analysis is carried out for hydrodynamic journal bearing system with smooth surface, and the results of the same are validated with results from the literature. In the later part of the paper, the partial rectangular shape micro-textures are modeled on bearing surface. The effects of partial groove pattern on the bearing performance parameters, namely, fluid film pressure, load carrying capacity, frictional power loss and frictional torque, are studied in detail. Findings The numerical results show that the values of maximum fluid film pressure, load carrying capacity, frictional power loss and frictional torque are considerably improved due to deterministic micro-textures. Bearing surface with partial groove along 90°-180° region results in 81.9 per cent improvement in maximum fluid film pressure and 75.9 per cent improvement in load carrying capacity as compared with smooth surface of journal bearing, with no increase in frictional power loss and frictional torque. Maximum decrease in frictional power loss and frictional torque is observed for partially grooving along 90°-360° region. The simulations are supported by proof-of-concept experimentation. Originality/value This study is useful in the appropriate selection of groove parameters on bearing surface to the bearing performance characteristics.

Analysis of Magneto Rheological Fluid Journal Bearing

2019 ◽  
Vol 895 ◽  
pp. 152-157 ◽  
Author(s):  
B. Narasimha Rao ◽  
A. Seshadri Sekhar
Keyword(s):  
Magnetic Field ◽  
Newtonian Fluid ◽  
Carrying Capacity ◽  
Smart Materials ◽  
Journal Bearing ◽  
Fluid Film ◽  
Load Carrying Capacity ◽  
Mr Fluid ◽  
Load Carrying ◽  
Magneto Rheological

Magneto Rheological (MR) fluids are a class of smart materials where the shear stress is not directly proportional to rate of shear. The viscosity of fluid changes as magnetic field changes and hence this phenomenon is very useful in bearing-rotor system for attenuating the vibrations. In the present study the application of MR fluid as lubricant instead of Newtonian fluid in the journal bearing is explored through steady state, dynamic characteristics and stability. MR fluid film has been modeled as per Bingham rheological model. FEM with three node triangular elements has been used to solve the Reynolds equation both for the Newtonian fluid film and MR fluid film. The results show the load carrying capacity in the case of MR fluid journal bearing is higher than that of using the Newtonian fluid. The load carrying capacity increases with the increasing magnetic field for all eccentricity ratios. The results also show better stability of the bearing using MR fluid at higher eccentricity ratios. The unbalance response of the rotor mounted on the journal bearing using MR fluid is also estimated to be lower than that of with the Newtonian fluid.

Hydrodynamic Analysis of Compliant Foil Bearings With Compressible Air Flow

2004 ◽  
Vol 126 (3) ◽  
pp. 542-546 ◽  
Author(s):  
Z.-C. Peng ◽  
M. M. Khonsari
Keyword(s):  
Carrying Capacity ◽  
Journal Bearing ◽  
Hydrodynamic Performance ◽  
Load Carrying Capacity ◽  
Bearing Surface ◽  
Hydrodynamic Analysis ◽  
Foil Bearings ◽  
Wide Range ◽  
Load Carrying ◽  
Good Agreement

A model is developed to predict the hydrodynamic performance of a foil journal bearing. The model accounts for both the compressibility of air and the compliance of the bearing surface. A series of predictions of the load-carrying capacity based on the numerical solution for pressure is presented that cover a wide range of operating speeds. The results show good agreement with existing experimental data.

Preload effects on the static characteristics of three-lobe journal bearings lubricated with a couple stress fluid

2019 ◽  
Vol 71 (10) ◽  
pp. 1136-1143 ◽  
Author(s):  
Boualem Chetti ◽  
Wael Ahmed Crosby
Keyword(s):  
Friction Coefficient ◽  
Carrying Capacity ◽  
Couple Stress ◽  
Journal Bearing ◽  
Significant Rise ◽  
Couple Stress Fluid ◽  
Load Carrying Capacity ◽  
Static Characteristics ◽  
Content Type ◽  
Load Carrying

Purpose The purpose of this paper is to present the effect of the preload on the static characteristics of three-lobe bearings lubricated with a fluid blended with high polymer additives modeled as a couple stress fluid. Design/methodology/approach Based on the micro-continuum theory, the modified Reynolds equation for couple stress fluids is solved using a finite difference method to obtain the distribution of the pressure, the load-carrying capacity, the attitude angle, the friction coefficient and the side leakage for various values of the couple stress parameter and the preload factor. Findings The results show that the presence of a couple stress in the lubricants improves the static characteristics of this type of bearing compared to those lubricated with Newtonian fluids for any value of the preload factor. Thus, it is found that the preload significantly affects the performance of the three-lobe journal bearing lubricated with a couple stress fluid or a Newtonian fluid. Moreover, the investigation showed that increasing the preload factor exhibits an increase in the load carrying capacity and the attitude angle, but it decreases the friction coefficient and the side leakage especially at a lower preload factor. Furthermore, using a couple stress fluid and a higher preload factor led to a significant rise in the load carrying capacity and a significant reduction in the friction coefficient. Practical implications This study helped improve the performance characteristics of the three-lobe journal bearing. Originality/value The presence of couple stress in the lubricants improves the static characteristics of this type of bearing compared to those lubricated with Newtonian fluids for any value of the preload factor. The usage of the couple stress fluid and the higher preload factor led to a significant rise in the load carrying capacity and a significant reduction in the friction coefficient.

CFD analysis of load-carrying capacity of hydrodynamic lubrication on a water-lubricated journal bearing

2015 ◽  
Vol 67 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Gao Gengyuan ◽  
Yin Zhongwei ◽  
Jiang Dan ◽  
Zhang Xiuli
Keyword(s):  
Carrying Capacity ◽  
Journal Bearing ◽  
Hydrodynamic Lubrication ◽  
Radial Clearance ◽  
Load Carrying Capacity ◽  
Cfd Analysis ◽  
Hydrodynamic Load ◽  
Oil And Grease ◽  
Content Type ◽  
Load Carrying

Purpose – The purpose of this paper is to improve hydrodynamic load-carrying capacity of a water-lubricated journal bearing by a new bush structure. Water-lubricated bearing is becoming more and more popular since it is environmentally friendly and saves energy. However, contrary to oil and grease-lubricated bearings, water-lubricated bearing is limited in many situations due to its low hydrodynamic load-carrying capacity. Design/methodology/approach – The present article proposes a new bearing bush, with a transition-arc structure, which is favorable for increasing hydrodynamic load-carrying capacity. Hydrodynamic load-carrying capacity was calculated by means of three-dimensional computational fluid dynamics (3-D CFD) analysis. Several variants of a journal bearing with a transition-arc structure of different dimensions are analyzed, while the radial clearance of the bearing, eccentricity ratio and the velocity of the journal remain unchanged. Findings – The results show that obvious changes are found in hydrodynamic load-carrying capacity of a water-lubricated journal bearing. For different width over diameter (L/D) bearing ratios, the relationship between hydrodynamic load-carrying capacity and the magnitude of the transition-arc structure dimension is researched. Originality/value – The research presented here leads to a design reference guideline that could be used by the designer engineer to design smart journal bearings for improving the hydrodynamic load-carrying capacity.

Linear extended state observer-based control of active lubrication for active hydrostatic journal bearing by monitoring bearing clearance

2019 ◽  
Vol 71 (7) ◽  
pp. 869-884 ◽  
Author(s):  
Waheed Ur Rehman ◽  
Jiang Guiyun ◽  
Luo Yuan Xin ◽  
Wang Yongqin ◽  
Nadeem Iqbal ◽  
...  
Keyword(s):  
Carrying Capacity ◽  
Journal Bearing ◽  
Servo Control ◽  
Load Carrying Capacity ◽  
State Variables ◽  
Dynamics Model ◽  
Mechatronic System ◽  
External Disturbances ◽  
Content Type ◽  
Load Carrying

Purpose This paper’s aim is modeling and simulation of an advanced controller design for a novel mechatronics system that consists of a hydrostatic journal bearing with servo control. The proposed mechatronic system has more worth in tribology applications as compared to the traditional hydrostatic bearing which has limited efficiency and poor performance because of lower stiffness and load-carrying capacity. The proposed mechatronic system takes advantage of active lubrication to improve stiffness, rotor’s stability and load-carrying capacity. Design/methodology/approach The current work proposes extended state observer-based controller to control the active lubrication for hydrostatic journal bearing. The advantage of using observer is to estimate unknown state variables and lumped effects because of unmodeled dynamics, model uncertainties, and unknown external disturbances. The effectiveness of the proposed mechatronic system is checked against the traditional hydrostatic bearing. Findings Proposed mechatronics active hydrostatic journal bearing system is checked against traditional hydrostatic journal bearing. It is found that novel active hydrostatic journal bearing with servo control has good tribology performance factors such as stiffness, less rotor vibration, no wear and friction under starting conditions and high load-carrying capacity under different conditions of spindle speed, temperature, initial oil pressure and external disturbance. The result shows that proposed mechatronics system has more worth in rotary tribology applications. Originality/value The current manuscript designs a novel active hydrostatic journal bearing system with servo control. The mathematical model has advantages in term of estimating unknown state variables and lumped effects because of unmodeled dynamics, model uncertainties and unknown external disturbances. The result shows improvement in dynamic characteristics of a hydrostatic journal bearing under different dynamic conditions.

Study of grease lubricated journal bearing with partial surface texture

2016 ◽  
Vol 68 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Rufei Yu ◽  
Pei Li ◽  
Wei Chen
Keyword(s):  
Friction Coefficient ◽  
Surface Texture ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Rheological Parameters ◽  
Load Carrying Capacity ◽  
Content Type ◽  
Research Results ◽  
Load Carrying ◽  
The Impact

Purpose – This paper aims to study the impact of surface texture on grease-lubricated journal bearing, load-carrying capacity, friction and friction coefficient. Design/methodology/approach – The paper opted for a basic application research using the commercial CFD software FLUENT 14.0. Findings – The load-carrying capacity can be enhanced if the surface texture is introduced from a suitable position. The textural shape has a more significant effect on the friction and load-carrying capacity than the friction coefficient. The rheological parameters of grease affect the load-carrying capacity in the same way, i.e. the load increases with the increase in the rheological parameters. With the decrease in the value of cavitation pressure, the cavitation area reduces but the dynamic pressure area gets enlarged. Research limitations/implications – Because of the chosen research method, the research results may lack the analysis of experiments. Practical implications – The research results can be applied to the domain in the high-speed spindle and lubricated multibody system. Originality/value – The investigation on the performances of grease-lubricated journal bearing with surface texture would be significant.

Effect of large-area texture/slip surface on journal bearing considering cavitation

2015 ◽  
Vol 67 (3) ◽  
pp. 216-226 ◽  
Author(s):  
Qiyin Lin ◽  
Zhengying Wei ◽  
Ning Wang ◽  
Wei Chen
Keyword(s):  
Boundary Condition ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Slip Surface ◽  
Load Carrying Capacity ◽  
Large Area ◽  
Texture Surface ◽  
Content Type ◽  
Load Carrying ◽  
The Impact

Purpose – The purpose of this paper is to study the influence of large-area texture/slip surface, especially the area and position of large-area texture surface on journal bearing, and improve the tribological performances of journal bearing. Design/methodology/approach – A modified texture/slip numerical boundary condition with double parameters is presented and is applied onto the region where surface textures locate to represent the impact of actual texture/slip surface. A phase change condition is used to analyze cavitation phenomena. Findings – The global/cumulative texture effect can be represented by applying texture/slip condition onto the region where it locates. The area and position of texture/slip surface would significantly affect the cavitation and load-carrying capacity. Texture/slip surface would not affect the pressure and load-carrying capacity when it locates at cavitation zone. The effect of texture/slip surface on load-carrying capacity would be beneficial if it locates at the pressure rise region, but its effect would be adverse if it locates at the pressure drop region. Well-designed texture/slip surface can improve tribological performances. Originality/value – The developed texture/slip boundary condition can be a suitable and useful tool to analyze the effect of large-area texture/slip surface and especially to optimize the area and position of large-area texture surface. This approach can be complementary to conventional approach which is used to analyze the influence of textures’ real configurations and parameters.

Influence of Surface Roughness on Non-Newtonian Thermohydrostatic Performance of a Hole-Entry Hybrid Journal Bearing

2007 ◽  
Vol 129 (3) ◽  
pp. 595-602 ◽  
Author(s):  
T. Nagaraju ◽  
Satish C. Sharma ◽  
S. C. Jain
Keyword(s):  
Surface Roughness ◽  
Thermal Effect ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Fluid Film ◽  
Load Carrying Capacity ◽  
Fluid Film Bearings ◽  
Load Carrying ◽  
Transverse Pattern ◽  
Newtonian Behavior

A general solution scheme to account the surface roughness and the cross-film viscosity variation of lubricant due to its non-Newtonian behavior and rise in fluid-film temperature for the analysis of fluid-film bearings is presented. The combined influence of surface roughness, non-Newtonian behavior of lubricant, and thermal effects on the performance of a hole-entry hybrid journal bearing system has been investigated. The surface roughness, especially stationary roughness (i.e., rough bearing and smooth journal) with a transverse pattern was found to partially compensate for the loss in load-carrying capacity due to the thermal and/or non-Newtonian behavior of lubricant effects. It limits 18.86% loss in load-carrying capacity due to the thermal effect to only 1.6% and 33.99% loss due to the combined influence of non-Newtonian lubricant and thermal effect to 16.76%.

Optimization of texture geometry for a rotating ring to maximum load-carrying capacity

2019 ◽  
Vol 71 (5) ◽  
pp. 657-663
Author(s):  
Zaihao Tian ◽  
Jin-Kui Ma ◽  
Lu Changhou ◽  
Shu-Jiang Chen
Keyword(s):  
Carrying Capacity ◽  
Maximum Load ◽  
Computational Domain ◽  
Load Carrying Capacity ◽  
Flat Bottom ◽  
Film Pressure ◽  
Content Type ◽  
Surface Textures ◽  
Surface Contour ◽  
Load Carrying

Purpose The purpose of this paper is to maximize the load-carrying capacity (LCC) of a rotating ring, a numerical model optimizing both the surface and bottom shape of its surface textures is proposed. Design/methodology/approach The Reynolds equation is used to evaluate the film pressure and LCC obtained by integrating the film pressure is set as the objective function. Around the center of the computational domain, radial lines with an equal angle between adjacent ones are produced and the surface contour of textures is obtained by connecting the endpoints using a spline curve. The bottom profile is then obtained by connecting the endpoints of two vertical lines at the circumferential ends of textures. Lengths of these lines are set as design variables and genetic algorithm is used to solve optimization models. Findings Results show that optimum textures have an “apple-like” surface contour and a “wedge-like” bottom profile, which are both expressed by smooth spline curves. Optimum wedge-bottom textures generate higher LCC than optimum flat-bottom textures. Moreover, the optimum textures have the highest LCC compared with optimum grooves proposed previously, which validates the practical value of the current optimization model. Originality/value This work presents a comprehensive optimization method of texture geometry, which provides a new idea of the design of surface textures.

The effect of liner surface texture on journal bearing performance under thermo-hydrodynamic conditions

2020 ◽  
Vol 72 (3) ◽  
pp. 405-414 ◽  
Author(s):  
Ahmed M. Saleh ◽  
Wael Crosby ◽  
Ibrahim M. El Fahham ◽  
M. Elhadary
Keyword(s):  
Surface Texture ◽  
Carrying Capacity ◽  
Journal Bearing ◽  
Hydrodynamic Condition ◽  
Load Carrying Capacity ◽  
Hydrodynamic Conditions ◽  
Texture Surface ◽  
Content Type ◽  
Load Carrying ◽  
Liner Surface

Purpose The purpose of this paper is to study the effect of liner surface texture on journal bearing performance. Modeling the profile curvature of the dimples or grooves is planned for different cases of texture surface under thermo-hydrodynamic condition (THD). The aim of this paper is to determine the effect the texture surface on the performance of journal bearing and specify the optimum shape for texture dimples. Design/methodology/approach The paper was opted for an exploratory study by applying finite difference method to solve the energy equation, the heat conduction equations and the Reynolds equation numerically. The lubricant film thickness is divided to a mesh of 640,000 points. The equations were solved for each point of the mesh by using a MATLAB code. For texture shape optimization, 24 cases of different texture shapes were selected which includes elliptical, triangle and square curvature shape. Findings The paper provides theoretical insights about the effect of texture shape on journal bearing performance. It was concluded that to get a high load-carrying capacity, the direction of curvature is preferably to be perpendicular to the sliding direction. The convex texture has higher load carrying capacity than concave texture. Finally, the surface with textures in channel form yields better overall performance than the surface with several dimples. Originality/value This paper fulfils an identified need to study how texture surface affects the performance of journal bearing under thermo-hydrodynamic conditions.

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