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The slip boundary has a significant impact on the effectiveness of hydrodynamic journal bearing. The slip boundary can be induced by the hydrophobic coating. The favorable influence of slip on thermal behavior, on the other hand, has received less attention. Parameters related to thermo hydrodynamic properties of heterogeneous type of bearing that operates in incompressible, stable, and turbulent states are investigated in this specific scope of research usin g CFD methods. The thermal hydrodynamic behavior of heterogeneous slip/no slip bearings is investigated in terms of volume fraction (VF), temperature, lubricating pressure, and load-carrying capacities when operating at various shaft rotational speeds. The journal bearing's actual operational condition is depicted using the multiphase cavitation model. It is discovered that shaft speed has a significant impact on the boundary condition of a het erogeneous journal bearing in terms of tribological performance. Besides, the maximum hydrodynamic lubricating pressure produced proportionally climbs as the shaft speed on the journal bearing increases. The findings show that as the shaft speed increases, so does the temperature of the lubricant. Moreover, it is found that the effect of slip is desirable in all simulated condition s sin ce it enhances the bearing load support, just as shaft speed does. [ABSTRACT FROM AUTHOR]

The nonlinear dynamic analysis has been carried out to investigate the dynamic behavior of a perfectly balanced horizontal rotor (HR)-tilting pad journal bearing (TPJB) system and perfectly balanced vertical rotor (VR)-tilting pad journal bearing (TPJB) system by computing frequency response of both the systems. To do so, governing differential equations (GDEs) of motion for HR-TPJB system and VR-TPJB system has been derived and they were solved by finite element method (FEM). The GDE of motion of both systems have been combined to form a unit set. This unit set represents the HR/VR-TPJB system. Implementation of computational numerical integration technique has been employed to solve equations of motion of both the systems which has been solved using the MATLAB® ODE-15s solver. Indigenous MATLAB® program has been created to compute the above-mentioned frequency response of the system efficiently. Time-Amplitude Response and Frequency-Amplitude Response with Phase at both the TPJB's and rigid disc locations have been computed by Fast Fourier Transform (FFT). The dynamic behavior of the perfectly balanced HR-TPJB and VR-TPJB systems have been analyzed for different rotor speeds. The results and discussions on the nonlinear dynamic behavior of perfectly balanced HR-TPJB and VR-TPJB systems operating at low and high rotor speed have been explained which indicates HR-disc is more unstable than HR-journal inside identical 4-pad TPJBs at low rotational speed (1500 rpm). The frequency response of both HR-TPJB system and VR-TPJB system at low speed (1500 rpm) shows that peak amplitude appeared much before in VR than HR, which indicates even in low rotational speed, VR-TPJB system is more unstable than HR-TPJB system. Results demonstrated that the balanced VR operated at high speed (6000 rpm) is more prone to instabilities than its horizontal counterpart (HR-TPJB system) at the same speed (6000 rpm). [ABSTRACT FROM AUTHOR]

The impact of introducing nanoparticles to lubricating oils on bearing dynamic characteristics, as well as their impact on the rotor's dynamical reaction and critical speed, has been studied. The lubrication oil pressure, reaction forces, and dynamic coefficients of journal bearings are calculated using the modified lubrication oil viscosity as a result of adding nanoparticle additions to the lubricant oil. According to the Reynolds equation's theoretical solution. The theoretical conclusions are verified using the computational fluid dynamics (CFD) fluent Ansys program. The results demonstrate that as the volume fraction of nanoparticles and aggregate fraction increases up to the angular position130, the lubrication fluid pressure increases, then decreases as both the volume fraction and aggregate fraction increase. [ABSTRACT FROM AUTHOR]

Numerical optimization technique in tribo-contacts is becoming crucial area of investigation during the last few years. This article illustrates the use of genetic algorithm optimization technique in textured hole-entry hybrid journal bearing system. In this paper, the texture surface parameters are optimized by multi-objective genetic algorithm to developed modified Reynolds equation. The modified Reynolds equation has been solved by finite element model for obtaining the bearing performance parameters. The static and dynamic performance parameters of hole-entry hybrid journal bearing have been simulated for non-textured, textured without GA and textured with GA surfaces. Based on the simulated results, the study indicates that the textured hole-entry journal bearing with genetic algorithm technique significantly enhanced the bearing performance. [ABSTRACT FROM AUTHOR]

Hydrodynamic journal bearing is one of the most cost-effective and efficient machine elements, without any external means to maintain lubricant pressure along the periphery of the shaft, used to support the rotating shaft. When the journal begins to rotate it drags the lubricant to the zone where sliding contact exists between the shaft and bearing surfaces. The pressure underneath the journal gets raised, and when the journal rotates faster and a wedge action takes place, and the bearing which lifts the journal and separates it from the bearing surfaces. If the lubricant viscosity is too low, then the wedge won't be formed at all and if the viscosity is too high, then the friction will quickly overheat the bearing. In this work we have added nanoparticles of several sizes and also used several volume fractions with the fluid and perform an analysis to see its result. Empirical formulas are taken into the account for the calculation of density and viscosity of nanofluids by using their diameter and the volume fraction. Computational fluid dynamics analysis is performed to analyze the effect of density and viscosity of nanofluid on the lubricant pressure during operation and FSI analysis is performed to investigate the effect of deformation on the bearing surfaces. Temperature can reduce the viscosity of the lubricant and due to this the film thickness reduces and thus higher pressure is generated resulting in a higher eccentricity ratio and better load-carrying capacity of the journal bearing. [ABSTRACT FROM AUTHOR]

This paper presents, the static study of hydrodynamic short journal bearing effective under Nano lubricants. Lubricant viscosity is affected the load resonant capacity of journal bearing. The performance of the bearing is influenced by the % of Nano particles added in the base lubricants. The current work modified Reynolds equation is utilized to get the pressure of the bearing. The narrow bearing estimation method is utilized to solve the modified Reynolds equation. For different eccentricity ratios the static characteristics in terms of load capacity, attitude angle and friction evaluated. [ABSTRACT FROM AUTHOR]

This study analyses the influence of the texture of the surface on the output of hydrokinetic articles. The job is split into two phases: 1. The technique of mechanical indenting with micro dimples to texture the bearing base. 2. Surface texture impact analysis on a flat, structured bearing with two loading axes with inlet holes±90°. Various investigational findings showed the impact of a micro-dimple on the redistribution of the pressure on the central region of a polished and rough journal at various weights and speeds. Test results demonstrate that load enhances as the surface texture is applied to the bearing surface. It was found that, with constant friction and constant demand for fuels, the percentage increases with low pressure and maximum pressure (percentage max) when embedded in smooth logs and the rise in speeds (from 1200 rpm to 3200 rpm). [ABSTRACT FROM AUTHOR]

Bearings, particularly hydrodynamic journal bearings, are crucial elements in the design of many dynamic pumps. The durability of the bearings determines the reliability of the entire pump unit. Unlike rolling bearings, for which there are generally accepted formulas and methodologies for determining the service life, there are no such methodologies for journal bearings, and determining the service life is still a problem for which no unambiguous solution has been found. In this paper, we propose the definition of the problem for determining the reliability indicators of hydrodynamic journal bearings. [ABSTRACT FROM AUTHOR]

Texture depth of textured journal bearing played an important role to predict the overall performance of journal bearing efficiently. Hence in this case study, the investigation was done on the effect of surface texture depth on the performance of journal bearing using computational fluid dynamic (CFD) ANSYS FLUENT. This case study also innovated the potential of refined bleached and deodorized (RBD) palm oil as a renewable source that can replace engine oil that is used in the application of journal bearing. The depth of texture was introduced at 0.049mm, 0.050mm, 0.051mm, 0.052mm and 0.053mm. The study was conducted at a different rotational speed of journal bearing start from 200rpm, 400rpm, 600rpm, 800rpm, and 1000rpm and at a constant eccentricity ratio of 0.7. As a result, depth texture of 0.050mm at a rotational speed of 800rpm and depth texture at 0.050mm,0.051mm, and 0.052mm at a rotational speed of 1000rpm showed a high value of maximum fluid film pressure as compared to plain journal bearing. The potential of RBD palm oil was fully studied during the simulation study and proved that these types of bio-lubricants can replace conventional oil in the future specifically in journal bearing applications. [ABSTRACT FROM AUTHOR]

This study considered hydrodynamic theory on magnetic fluid flow models like R. E. Rosensweig model and Jenkins model for axially undefined journal bearing with porous attached at inner surface (journal). In this work variable external magnetic field is considered. Expressions of pressure and load carrying capacity are obtained. The values of load carrying capacity for both the models are calculated for various parameters like slip velocity, porous thickness, squeeze velocity, eccentricity, permeability. It is observed that in comparison point of view, the better performance in case of a flow model depends on values of parameters for designing the porous journal bearing. [ABSTRACT FROM AUTHOR]

One of the main challenges in engineering is the maintenance of the journal bearings, which requires significant time and effort. In this work, a new design for a journal bearings system was thus developed to reduce friction, potentially bearing relatively higher loads based on duplicating pressure, and to support an enhanced and persistent oil viscosity due to the use of Nano Lubrication, which should maintain the mechanical system at a consistent temperature to accomplish these aims, a mathematical model for a new journal bearing design was developed and resolved using the Reynold's equation and applying the finite difference method. MATLAB code was then developed to solve the governing partial differential equation to find the journal bearing parameters. The preliminary results of this work indicate an increase in pressure value of 50% as compared with traditional bearings. Furthermore, the new design appears to maintain a consistent oil viscosity and temperature based on adding Nano-particles to the system and improving all bearing parameters. [ABSTRACT FROM AUTHOR]

The influence of cavitation and surface roughness on journal bearings has been extensively researched. Even though many studies have been done on elastohydrodynamic lubrication, further research is needed. The majority of research has focused on hydrodynamic lubrication on fluid films without taking into account their interaction with the housing and shaft, or on hydrodynamic lubrication alone. The impacts of roughness on elastohydrodynamic lubrication, as represented by CFD using structural transients' module, will be discussed in this work. The 2-way FSI coupling method is the name given to this form of coupling (Fluid-Structure Interaction). For cavitation and without cavitation, as well as for many types of roughness, this study examines hydrodynamic pressure, load carrying capacity, friction force, and von Mises stress. When considering cavitation, it was established that the value of load-carrying capacity and friction force is decreasing. Furthermore, as the level of surface roughness rises, the maximum hydrodynamic pressure, load carrying capacity, friction force, and von Mises stress decrease. [ABSTRACT FROM AUTHOR]

Lubricant viscosity is determined by temperature distribution, design of lubricant analysis is essential. In this study, the performance of a journal bearing was investigated. The surface materials are treated using a hydrophobic coating to obtain an artificial slip. The simulation is carried out using 3D modeling of CFD. In this study, the hydrophobic coating on journal bearing is varied using FSI Computational Fluid Dynamic (CFD) Method. Furthermore, the effect of turbulence is also considered. The simulation results show that the turbulence effect reduces the load-carrying capacity compared to the journal bearing under laminar conditions irrespective of the turbulence model. It is also found that the hydrophobic coating has a strong effect on altering the fluid behavior, specifically in load-carrying capacity. A hydrophobic coating can obtain the improved performance of journal bearing. [ABSTRACT FROM AUTHOR]

Surface roughness has always impacted hydrodynamic lubrication, particularly in journal bearings, due to pressure distribution, load support, film thickness, and cavitation. Most studies have not considered the shaft distortion and housing caused by lubrication pressure. By addressing the cavitation effect, this study investigates the impact of surface roughness on journal bearing lubrication performance (pressure, load support, and deformation). The k-epsilon turbulence model is used for Newtonian and incompressible fluids, and the surface roughness is assumed to follow the uniform sand-grain roughness model. Numerical analysis with 2-way Fluid-Structure Interaction (FSI) method is used by considering the cavitation model of Schnerr-Sauer. The numerical analysis reveals that increasing surface roughness will decrease the pressure, load support, and deformation. The performance of the journal bearing can be improved by applying artificial surface roughness. [ABSTRACT FROM AUTHOR]

The aim of numerical investigation is to emphasize the performance of a hydrodynamic journal bearing by introducing deterministic surface texturing on the bearing circumferential surface. Design/Methodology/Approach-The performance and characteristics of the journal bearing is studied by numerically in the COMSOL Multiphysics 5.0 Software by using thin film flow physics. The aim of this research is to look into, improve, and to optimize the characteristics of a hydrodynamic journal bearing by adding deterministic partial surface texturing to the bearing surface. In the further part of the paper the deterministic micro textures of shapes like rectangular, triangular, elliptical, circular grooves and micro dimples are modeled on the surface of bearing. These textures are investigated for their effect on bearing performance characteristics such as maximum film pressure, power loss due to friction, friction torque, and load bearing capacity. From the results, the micro-texture generated on the bearing circumferential surface is found to significantly increase parameters such as maximum film pressure, power loss due to friction, friction torque and load bearing capacity. The 0˚-135˚ rectangular grooved journal bearing shows the better results. It has an improvement of about 132.17% and 43.97% in load carrying capacity maximum fluid film pressure respectively. [ABSTRACT FROM AUTHOR]

In this work, the performance of AL-MMC-based hydrodynamic journal bearing is analyzed by using various samples of lubricants type 24, 25, and 26 with added different concentrations of nanoparticles such as TiO2. The material used in the manufacturing of the Hydrodynamic Bearing is Al metal matrix composite i.e. Al and Zrb2. The important parameters considered while selecting a lubricant are viscosity, density, and additives in the lubricant. Nano-particles of TiO2 are used as additives in the lubricant to improve its tribo-mechanical properties like friction and heat generation, pressure distribution, lubricant film thickness, etc. To investigate the above tribological properties, the CFD tool is used. The effect of addition of Nano-particles to the lubricant gives optimized result of the HDJB such as pressure and load-carrying capacity in the terms of deformation and equivalent stress. [ABSTRACT FROM AUTHOR]

Nanoscale is defined as a measurement of less than one tenth of a micrometre in at least one dimension. This setting depicts the usage of CuO nanoparticles as additives in the development of Nano lubricants with varying CuO particle concentrations in 60(water)-40(EG). Chemical precipitation was used to make the nanoparticles, which were stabilised using polyvinyl alcohol (PVA). Using the X-ray powder diffraction method, the resulting powder was characterised. CuO nanoparticles have a particle size in the range of 100 to 120 nm, according with report. The Anton Par Rheometer was used to test various solutions with various volume concentrations, including such 0.125gm, 0.250gm, 0.50gm, and 0.75gm. The result indicated that addition CuO nanoparticles to the mixture enhances shear rate, viscosity, and torque characteristics of the mixture and as concentration of particles increases viscosity increases.We can say that CuO nanoparticles added into mixture of water and EG with definite proportion can be used as lubricant for hydrodynamic journal bearing. [ABSTRACT FROM AUTHOR]

Fluid film bearings are used in heavy machinery for supporting loads which are subjected to either static or dynamic. Due to this load the rotating shafts centres move away from the centre of the bearing. Due to this deviation of the journal axis from the bearing centre eccentricity is developed. This pulls the journal near to the bearing surface by decreasing the film thickness between the journal and bearing during relative motion. The film pressure is increased to at an edge, which leads to vibrations of the journal. The uneven pressure distribution can be reduced by dividing the projected area of the bearing into lobes. These lobes create film pressure which supports the journal during loading. In this paper three lobe journal bearing characteristics have been investigated for different eccentricity ratios. The journal trajectory is plotted for eccentricity ratio considered from the experimental investigation. The effect of eccentricity ratio on the journal centre trajectory is studied. [ABSTRACT FROM AUTHOR]

Developing a Metal Matrix Composite (MMC) with 5, 10 & 15 weight % of fly ash and 4 weight % of talc using stir casting technique. This composite material has the benefit of developing a lubrication effect over the elevated temperature and where, it is tedious to maintain the lubricating property. They possess their utilizations in journal bearings, engine cylinder linings, piston etc. Drilling parameters are optimized with the help of input variables obtained using a drilling machine. L9 array model was developed with the help of MINITAB software. Using the data obtained from surface roughness and hardness test, a model iscreated. The input data was examined using the L9 array model. Developed L9 array model grants to trim down the experimentation work also decrease the manufacturing cost as well as testing cost. [ABSTRACT FROM AUTHOR]

Used lubricant becomes an issue for environment due to disposal techniques and reuse of it through filtering process is the best technique. This paper tried to determine the characteristics of physical and tribological properties of used lubricant from a filtering process. The used lubricant was collected in service from a car engine after running about 6000 km. A Whatman filter paper was used to reduce impurities in used lubricant. The used lubricants were characterized physically to determine kinematic viscosity, density, pour point, and flash point and tribologically to measure wear rate, CoF, surface texture, scar width of disc, and scar diameter of pin using pin on disc apparatus. The results were compared with virgin oil and they show that the physical and tribological properties of used lubricant were decreased compared to virgin oil. The tribological properties of used oil were good lubrication at a speed of 1400 rpm than 500 rpm. [ABSTRACT FROM AUTHOR]

The hydrodynamic application used in journal bearing handles the load with lubricant film between the shaft and sleeve. One of the major concerns is pressure developed across the circumference and axis to load handling capacity. The bearing operation is substantially impacted by the state and speed of bearing. The rise of pressure because of high-speed rotating machinery. The journal bearings that use water as lubricant are being used in the ships, hydro power industries and others due to extensive durable life, endurance of shaft sleeve, minimal frictional co-efficient, minimal maintenance required, better abrasion resistance, unit simplicity and low price. They are also ecofriendly as they are pollution free. Less than 5% of the marine transportation in the world uses open sea water lubricated propeller shaft bearing system. In open seas, water lubricated system uses the natural medium as the lubricant instead of oil. The main aim is Modelling of sea water lubricated bearing for marine systems by using proper values of design constraints and impact of eccentricity ratio, distribution of pressure and load bearing capacity. We use Solid works software for modelling and Ansys Fluent Software for analysis. [ABSTRACT FROM AUTHOR]

The paper considers the main integral and dynamic characteristics of a rotor system on hydrodynamic journal bearings lubricated with a magnetorheological fluid. A new design has been proposed in the field of active journal bearings for lubrication by magnetorheological fluids, namely, a journal bearing with full coverage of the gap area by a magnetic field. The basic mathematical relationships, initial and boundary conditions used for calculation of the bearing characteristics are given. Distributions of the friction coefficient, relative eccentricity, stiffness and damping parameters are given. The trajectories of movement of the center of the rotor in various operating modes are presented. Conclusions about the applicability of magnetorheological lubricants for controlling the dynamic characteristics of a rotor on journal bearings lubricated with magnetorheological fluids are presented. [ABSTRACT FROM AUTHOR]

Control of linear dimensions in mechanical engineering can have carried out for two purposes. The first goal is to determine the size of the quantity in absolute units with the required precision. The second goal is to determine the suitability of the part, that is, the fact that its size is in the range of limiting dimensions, characterized by the tolerance. The second goal is easiest to accomplish with gauges, which increase accuracy and reduce the labor intensity of inspection. It had revealed that the standard gauge for monitoring the diameter 0 54 − 0.105 − 0.065 of the bearing journals of the camshaft of YaMZ engines cannot be used, since the tolerance is between the standard values IT7=30 µm and IT8=46 µm, and the deviations are so they are not-standard from the standpoint of the system of tolerances and fits according to ISO 286-1: 2010. The calculation of the executive dimensions of the snap-gauge for diameter control 0 54 − 0.105 − 0.065 of the bearing journals of the camshaft of YaMZ engines during the overhaul of engines. The tolerance for the production of the go and not-go sides has determined, which is 7 microns. The magnitude of the inward shift in the middle of the tolerance fit of the passage side was - 6 µm. The wear limit had assumed to be 3 µm, as it is normalized for gauges that control IT7 tolerances. The tolerance for the manufacture of the dimensions of the control gauge was taken equal to 3 microns, the calculation of the limiting dimensions of the control gauge had performed. A diagram of the location of the tolerance fits of the snap-gauge for controlling the diameter 0 54 − 0.105 − 0.065 of the bearing journals of the camshaft of YaMZ engines has been built. [ABSTRACT FROM AUTHOR]

ER fluid is a smart fluid whose influence on the journal bearing has been studied in present work. The Reynolds equation has been solved using the finite element method. Dynamic performance characteristics such as stiffness coefficients and damping coefficients have been analysed. The influence of ER fluid on the hybrid journal bearing has been compared with Newtonian lubricant. Results show a significant improvement in dynamic coefficients using ER fluid as a lubricant. For different values of C̄s2 (i.e., 0.06 to 0.18), stiffness coefficients and the damping coefficients are enhanced for ER fluid lubricated bearing in comparison with the Newtonian fluid lubricated bearing system. The ER effect is found to be higher for high voltage. It has been concluded that the decrease in S̄xx and S̄zz are observed to be 20% and 15% respectively. In contrast, an increase in C̄xx and C̄zz are 10% and 10.7% respectively for orifice compensated hybrid journal bearing. [ABSTRACT FROM AUTHOR]

The design and optimization of hydrodynamic journal bearing is most required because of their usage supports machineries which rotate at high speeds such as compressors and turbines. It is difficult to optimize the bearing parameters using conventional algorithms as they require non-linear optimization with constraints. Genetic Algorithms (GAs) is a general purpose algorithm that could achieve the process parameters with all the available constraints. In this work, the geometric parameters and their range such as variance ratio (0 - 1), journal radius (25 - 65), radial clearance (30 - 60), dynamic viscosity (0.026 - 0.046), surface pattern parameters (1/6) and surface roughness parameter (15 - 30) were used as an input for training the ANN model and to evaluate the performance parameters that would result in optimal value of minimum fluid film thickness, frictional torque and critical journal mass of journal bearing. This has been separately carried out for three bearings having transverse type of roughness patterns using the Multi Objective Genetic algorithm (MOGA) approach. Using Pareto optimal concept, the optimization of design parameters has been evaluated. The designed model using MOGA Approach exhibits the satisfying response compared to experimented data for the roughness pattern. [ABSTRACT FROM AUTHOR]

Hydrodynamic journal bearings have been widely used in heavy industry machinery to support rotating shafts due to their superior durability, low maintenance cost, and excellent load capacity. Inorganic fullerene-like tungsten disulfide nanoparticles (IF-WS2 NPs) are the most studied additive for lubrication purpose due to their excellent mechanical characteristics. In this work, a numerical simulation approach with discrete phase modeling of suspended nanoparticles was used to evaluate the load carrying capacity of journal bearings in heavy industry where the normal loads are very high relative to the bearing footprint. For accurate simulation, nanofluid viscosity was calculated using available empirical models, considering the aggregation effect of NPs. To characterize the aggregations of nanoparticles, scanning electron microscopy (SEM) imaging of the nanofluid samples were employed. The simulated pressure distribution was then used to calculate the load capacity of the bearing. The results show about 20% improvement of load capacity at 5% weight fraction of IF-WS2 nanofluid. [ABSTRACT FROM AUTHOR]

The primary function of a journal bearing is to hold up radial loads under different working conditions. In a journal bearing, in order to avoid metal to metal contact, the pressure is created in the thin lubricant oil film that detaches the shaft and the journal. For a Newtonian fluid, A generalized Reynolds equation has been applied to examine the geometrical analysis of Elliptical Journal Bearing. Further, the variation of film thickness and pressure profile with respect to circumferential angle has been plotted by considering the changes in parameters like eccentricity and non-circularity. The result shows that with the increase of eccentricity ratio the pressure gets increased whereas peak film thickness before and after convergence increases. With the help of a pressure profile, the load-bearing capacity of the bearing is obtained. In this study, MATLAB has been used as the programming tool and various routine of MATLAB graphics helps us to draw the results. For non-circularity of 0.7, the non-dimensional load-bearing capacity is estimated to be 2.25, 2.75, and 3.45 at journal eccentricities of 0.5, 0.7, and 0.9 respectively. [ABSTRACT FROM AUTHOR]

The present research work is carried out to investigate the effect of Hydrol 68 grade oils on elliptical journal bearing. Experiments are carried out on hydrodynamic journal bearing test rig to evaluate the lubricating oil temperature and pressure at the mid plane and ends of the circumferential bearing. Hydrogel68 lubricating oil at different loads (100N, 200N and 300N) and speed (1000, 2000 and 3000 RPM) at constant feeding pressure (0.25 Mpa) is applied on journal bearing of 6.52cm inner diameter and 8.5 cm of outer diameter. Results reported the Hydrol 68 oil with an constant speed and varying loads, to evaluate temperature and pressure is observed along the mid plane and ends for different circumferential angles. [ABSTRACT FROM AUTHOR]

In this static analysis has been performed for the crankshaft of four stroke single cylinder engine under fatigue stacking conditions. The primary target of this work is to demonstrate the crankshaft with measurements and accelerate the crankshaft for static and fatigue analysis. The business programming SOLIDWORKS 2013 is utilized for displaying the wrench shaft. The analysis programming ANSYS 14.5 is utilized for static and fatigue analysis of crank shaft. The finite element analysis was done for the current model of a 150cc motor crankshaft. The outcome shows that the greatest stress happens at the intersection of crankpin-crank arm and crankpin-main bearing journal. To acquire better life and to expand the life of the crankshaft, some structure adjustments were made by shifting the plan parameters in the overall crankshaft. Three models of crankshaft were acquired by presenting a different blend of structure parameters, for example, oil opening profundity, filet sweep, wrench geometry and crankpin gap to the Existing model. The quality and the life of the altered crankshafts were acquired by finite element analysis. The outcome of the current model and the changed models are looked at. From the examination, Modified model II shows preferred outcome over the other crankshaft models as far as quality and life. [ABSTRACT FROM AUTHOR]

The aim of this paper is to find out the importance of aspect ratio as a shape parameter of wear debris in the fault diagnosis of journal bearing installed in hydel power plant. Condition monitoring of tribo-pair is done online as well as offline. Four oil samples are collected at different interval of time and wear debris are filtered out for the microscopic examination. A sharp increase is noticed in aspect ratio of wear debris and in the temperature of journal bearing. Bearing temperature is noticed above 80°C that is too high and the value of aspect ratio is observed more than 5 after 200 days of running of hydro power plant that is also undesirable. Hence the journal bearing is decided to dismantle for proper diagnosis. On dismantling of journal bearing, deep scratch marks are found. Aspect ratio is proved to be a suitable parameter to predict the scratch marks in the Babbitt material of bearing block. [ABSTRACT FROM AUTHOR]

An analytical model has been developed to analyse the effect of turbulence in fluid flow in TPJB on fluid film properties. A four pad centrally pivoted tilting pad journal bearing has considered for analysis. The infinite short bearing assumption has taken for determination of fluid film pressure distribution. The fluid film forces with turbulence effect find out by replacement of the numerical integration with the corresponding pressure distribution with a differentiation method which found to be less computational costly. The indigenous MatlabTM code has made for investigation purpose. Change in fluid film properties presented in the form of plots concerning journal eccentricity ratio and journal rotation speeds. Investigation showed that turbulence in oil flow influences the circumferential and axial pressure, fluid film forces and bearing stiffness and damping coefficients. [ABSTRACT FROM AUTHOR]

An analytical model has been developed to analyze the effect of pad rotation angle on fluid film properties. A four pad centrally pivoted tilting pad journal bearing has considered for analysis. The infinite short bearing assumption has taken for determination of fluid film pressure and fluid film forces. The indigenous MatlabTM code has made for investigation purpose. Results presented in the form of graphs concerning journal eccentricity ratios and pad rotational angles. Investigation showed that positive pad rotation influences the axial pressure, fluid film thickness, fluid film forces along with pads and bearing stiffness and damping coefficients. [ABSTRACT FROM AUTHOR]

Hydraulic servo cylinders are widely used in versatile industrial applications such as machine tools, industrial robots, autonomous manufacturing systems and special applications in laboratories. To reduce friction and allow smooth and controllable displacement of the actuator, hydrostatic journal bearings are used at the ends of the rod. The design and manufacturing of this elements is challenging since the good operation relays on the very small tolerances required to bear the load on the cylinder and to reduce leakages. In this work, a virtual design and test tool for hydrostatic journal bearing with pockets, developed in OpenModelica environment, is presented. The influence of eccentricity and manufacturing tolerances is then studied and discussed. The model proposed has the aim to explore the extreme and critical operating conditions of the servo-cylinder and to help and/or improve the design phase. [ABSTRACT FROM AUTHOR]

The multilobe hydrodynamic journal bearing has been analyzed on the basis of the static pressure that developed in the system. The characteristics of four-lobe hydrodynamic journal bearing have conducted by CFD simulation software based on the Navier Stokes equation. The simulation results then validate with the experimental results. The performance of four lobe hydrodynamic journal bearing is superior compared to plain journal bearing at low-speed applications. [ABSTRACT FROM AUTHOR]

DeepWind has attracted scientific attention. This is due to its design simplicity, which will reduce costs for installation, operation and maintenance of a deep sea offshore wind generator system. Using this design offers advantages of alternative ways to manufacture the turbine rotor parts, introduce new materials, a novel way to implement a direct drive, Permanent Magnet Generator (PMG) and bearing technology, and a design that offers a reduced cost of energy. DeepWind uses a generator and bearings module, supported by controlled magnetic bearings technology. However, many technologies implemented in DeepWind are well known from other applications (e.g. Wind Energy, Sub-sea installations, Offshore installations). This paper presents the controlled magnetic bearings proposed for DeepWind. [ABSTRACT FROM AUTHOR]

Hydrodynamically lubricated journal bearings are traditionally designed using Reynolds boundary condition which is questionable. This theory provides acceptable results for modelling cavitation in bearing, but a better understanding of the characteristics including cavitation can be achieved by modeling multi-phase flow. For this reason, the main aim of this study is to investigate the effect of the eccentricity ratio on the performance of the journal bearing including multi-phase cavitation based on computational fluid dynamic (CFD) method. The Navier-Stokes and the continuity equation, as well as the cavitation models, have been solved by the finite volume method. The simulation results show that increasing the eccentricity ratio will enhance the hydrodynamic pressure as well as the load support. However, a contrary result is found in terms of friction force. The large eccentricity ratio does not much affect the friction force. [ABSTRACT FROM AUTHOR]

This paper presents a comparison of performance characteristics of a hydrodynamic journal bearing lubricated with plain engine oil, Ferrofluid and Magnetorheological (MR) fluid. The magnetorheological behaviour of micro and nano sized magnetic particles dispersed in silicone oil is analysed and their effects on bearing characteristics is studied. A test bearing with provision to vary the magnetic field strength is used for the study. The frictional force in the bearing is measured using torque arm principle. Dispersion of the additives is achieved by mechanical agitation and immediately tested to negate the problem of dispersion stability. The variation of frictional force at various bearing speeds is obtained by using plain engine oil as lubricant and then compared with the frictional force variation on lubricating with MR fluids and Ferrofluids of different volume fractions subjected to varying magnetic field strengths. It was observed that the MR Fluids show a significant change in rheological characteristics for varying strengths of magnetic fields. The frictional forces at the bearing surface when lubricated with magnetized MR fluid was much higher compared to that generated with plain engine oil; however the frictional force generated when lubricated with magnetized Ferrofluid was much lower than the frictional force in MR Fluid lubrication subjected to the same magnetic field. Results show significant increase in load bearing capacity of journal bearing when lubricated with MR fluids as opposed to plain engine oil. [ABSTRACT FROM AUTHOR]

In this paper the optimum geometry of journal bearings is determined for the minimum possible viscosity of the lubricant. During the investigations the basic equation of the THD (Thermo-Hydrodynamic) state of hydrodynamic journal bearings is solved by using the finite difference technique, while for the optimization the RVA (Random Virus Algorithm) is used. Design variables are the coordinates of the 40 keypoints selected for creating the finite difference mesh. All the operational and geometry limits are included as implicit constraints. As the result of the optimization process, the lubricant viscosity can be considerably decreased compared to the starting design, this makes possible to apply water as lubricant in the bearing. This will decrease the lubricant cost by more than 95%, which is a very important achievement. [ABSTRACT FROM AUTHOR]

The journals bearing characteristics with texture presence on the bearing surface are investigated. The thermal effect has been studied. The used numerical approach in this analysis is Finite Difference Method. The textured bearing performance enhancement passes essentially by a minimum film thickness and a friction torque improvement through an appropriate surface texture geometry and right texture distribution on the bearing surface. It is found that the simulation results are in good concordance with those issued from the litterature. The obtained results by considering the temperature effect are more realistic. [ABSTRACT FROM AUTHOR]

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Journal bearings are applied in internal combustion engines due to their favourable wearing quality and operating characteristics. Under certain operating conditions damage of the journal bearing can occur caused by cavitation. The cavitation reduces the load capacity and leads to material erosion. Experimental investigations of cavitating flows in dimension of real journal bearing are difficult to realize or almost impossible caused by the small gap and transient flow conditions. Therefore numerical simulation is a very helpful engineering tool to research the cavitation behaviour. The CFD-Code OpenFOAM is used to analyse the flow field inside the bearing. The numerical cavitation model based on a bubble dynamic approach and requires necessary initial parameter for the calculation, such as nuclei bubble diameter, the number of nuclei and two empirical constants. The first part of this paper shows the influence of these parameters on the solution. For the adjustment of the parameters an experiment of Jakobsson et.al. [1] was used to validate the numerical flow model. The parameters have been varied according to the method Design of Experiments (DoE). With a defined model equation the parameters determined, to identify the parameter for CFD-calculations in comparison to the experimental values. The second part of the paper presents investigations on different geometrical changes in the bearing geometry. The effect of these geometrical changes on cavitation was compared with experimental results from Wollfarth [2] and Garner et.al. [3]. [ABSTRACT FROM AUTHOR]