Gear Oil Research Articles

Improved SPH simulation of spilled oil contained by flexible floating boom under wave–current coupling condition

A multi-phase Smoothed Particle Hydrodynamics (SPH) method is developed to model the failure process of a flexible oil boom. An algorithm is proposed based on the dynamic boundary particles (DBPs) for preventing particle disorders of multi-phase fluid particle movement around solid boundary. The improved multi-phase SPH model is firstly validated by the experimental data of a wedge falling into a two-layer oil–water fluid. Then a numerical wave–current flume is established with a piston-type active absorbing wave generator and a circulating current system. The model reliability is validated against the measured vertical profiles of velocity. Simulation of the flexible floating boom movement is implemented by introducing a Rigid Module and Flexible Connector (RMFC) multi-body system. The model is finally applied to the simulation of movement of a flexible floating boom in containing industrial gear oil under the action of combined waves and currents. Good agreements are obtained between the SPH modeling results and the experimental data in terms of the ambient wave–current field, hydrodynamic responses of the floating body and evolution process of the oil slick for the flexible boom. The hydrodynamic responses and containment performances of the flexible floating boom are also compared with those of the rigid one. It is found from both the experimental and numerical results that two vortices of the water phase exist in the front and rear of the boom skirt and the size of the front vortex decreases with increase of the current velocity while the wake vortex is reversed. It is also found that the skirt of the flexible boom has a larger magnitude of swaying and rolling than the rigid one and the maximum quantity of escaped oil of a flexible boom within one wave cycle is about 5% more than a rigid one under the present test conditions.

Multi-Objective Optimization of Spur Gearbox with Inclusion of Tribological Aspects

In this paper, a novel multi-objective optimization of a two-stage spur gearbox is carried out with a comprehensive range of constraints. The first objective function aims to reduce the weight/volume and second aims to minimize the power losses in the gearbox. Various design constraints and tribological constraints such as scuffing and wear are included. By using a specially formulated discrete version of NSGA-II optimization code, these objective functions are minimized for three different gear profiles (unmodified profile, smooth meshing, and high load) and for different SAE oil grades. Optimization is first carried out based on standard single objective minimization using regular constraints based on existing literature and then based on multi-objective optimization with comprehensive constraints which include tribological aspects. Finally, these two cases are compared for different gear profiles and oils. The results indicate that there is a high probability of wear failure, for solutions obtained from single objective minimization. The total power loss is reduced by half when using multi-objective compared to single objective optimization.

Performance of lubricating oils for wind turbine gear boxes and bearings

In this study, the friction and wear properties of six different new and used wind turbine gear oils (ISO VG 320), with different base oil formulations and additives packages, were investigated. For that purpose, a four-ball tribometer and an Optimol SRV were used. Moreover, the lubricants extreme pressure properties were also evaluated, using the same four-ball tribometer. The study also includes a characterization of the lubricants. The main objective was to compare the new and used gear oils in order to identify performance differences and predict oil change intervals. The results indicate that a use of 3 to 4 years is within the lifetime of the lubricant.

Influence of mass temperature on gear scuffing

Abstract A new scuffing parameter for gears lubricated with mineral base oils is developed, proposing the existence of gear mass temperatures which are critical for each lubricant (viscosity grade). The introduction of the total cycle of the gear for mass temperatures calculation is supported by a theoretical background that was clearly established without empirical formulation and without any geometrical gear specificity which provides consistent physical support to the proposed scuffing parameter. The oil dynamic viscosity at the critical mass temperatures is constant, allowing the prediction of critical temperatures for other viscosity grades of the mineral gear oils without the need of additional scuffing tests.

CFD analysis on natural convective heat transfer of Al2O3-gear oil nanolubricant used in HEMM

PurposeThe present work aims to numerically investigate the natural convective heat transfer performance of aluminium oxide (Al2O3)-gear oil nanolubricant used in heavy earth moving machinery (HEMM).Design/methodology/approachViscosity, density and thermal conductivity of nanolubricants have been experimentally determined. The numerical simulation has been performed by using computational fluid dynamics (CFD) for a cylinder cavity which resembles shape of automatic transmission system of HEMM. The left wall temperature has been maintained at 293 to 313 K, and right wall is at a constant temperature of 283 K. Due to absence of any experimental study on natural convective heat transfer performance of Al2O3-gear oil nanolubricant, initially CFD model has been tested for accuracy by comparing experimental, and CFD results for Al2O3-water nanofluid has been available in open literature.FindingsIt has been observed that Nusselt number increases with increase in Rayleigh number, but it decreases with increasing particle volume fraction. The gear oil-based nanolubricant is expected to have the better thermal performance in HEMM at higher temperature.Practical implicationsThe numerical analysis will help to predict the thermal performance of nanolubricant. The outcome may help the designers, researchers and manufacturers of HEMM.Originality/valueMost of the previous studies have been limited with base fluid as water, ethylene glycol, etc. in the field of nanofluid. CFD study for thermal performance of Al2O3-gear oil nanolubricant is essential before the experimental work. This work is the preliminary stage of application of, nanolubricant for heat transfer.

Is there a frontier in sensitivity with Lossy mode resonance (LMR) based refractometers?

A tin dioxide thin layer has been studied in order to improve the sensitivity of lossy mode resonances (LMR) based sensors. The effects of the thin film thickness and the polarization of light in a SnO2 coated D-shaped single mode optical fiber have been evaluated. The optimization of such parameters in the fabrication of refractometers have led to an unprecedented sensitivity of over one million nanometers per refractive index unit (RIU), which means a sensitivity below 10−9 RIU with a pm resolution detector. This achievement is a milestone for the development of new high sensitivity devices and opens the door to new industrial applications, such as gear oil degradation, or biomedical devices where previous devices could not provide enough sensitivity.

The bio-hydrogen production by yersinia's genus, pasteurella and acinetobacter from wastewater which contained walnut oil, grape seed oil or gear oil

The current study examines effects of exposure in multiple contexts on fear reduction and renewal and the moderating effect of baseline threat-specific and nonspecific emotionality.Snake-fearful participants received a negative or neutral emotion induction and were randomized to video exposure to a snake in a single context, multiple context, or a no exposure control group.Anxiety in response to video presentations of a snake was significantly reduced in the two exposure groups compared to the control group, especially among those with heightened baseline threat-specific emotionality as indicated by snake anxiety ratings at baseline. Although the two exposure groups did not differ in responding when confronted with a novel snake, both exposure groups reported significantly lower snake anxiety and arousal than the control group. Subsequent analysis did show that compared to controls, the single context group demonstrated greater increase in anxiety and arousal from post-exposure to exposure to the novel snake among those with heightened snake anxiety at baseline. Furthermore, the multiple context group was less avoidant and less fearful than the single context group on a post-exposure behavioral test.The study used an analogue exposure paradigm with an analogue sample and findings may not be generalizable to a clinical population.These findings suggest that baseline threat-specific emotionality influences fear reduction and renewal. The benefits of exposure in multiple contexts are discussed in relation to a distinct pattern of symptom change that is in line with an inhibitory learning approach.

Direct acetylation of sunflower oil in the presence of boron trioxide catalyst and the adduct usage as the base stock and lubricant additive

Lubrication properties of sunflower oil have been modified by epoxidation in the first step and acetylation of the obtained epoxide in the second step. Epoxidation has been followed in dichloromethane solution in the presence of hydrogen peroxide and acetic acid as oxidizing agent and sulfuric acid as catalyst. The reaction has been monitored and optimized by measurement of iodine value, epoxy content, and recording the FTIR spectrum at different experimental conditions. Acetylation has been performed by enduring the optimized conditions of epoxidation reaction, in the presence of boron trioxide as catalyst and at elevated temperature. The recent reaction has been monitored and optimized by measurement of hydroxyl value, epoxy content, and recording the FTIR spectrum at different experimental conditions. The final product of both,epoxidation and acetylation reactions has been confirmed by FTIR and NMR data. Relative to sunflower oil, pour point and oxidation stability of the modified oil has considerably been improved. The modified oil has successfully been employed in the formulation of industrial gear oil. The investigation on the possibility of the additive application of the modified oil, as well as its miscibility with additives was considered. KEY WORDS : Sunflower oil, Lubrication, Epoxidation, Acetylation, Borontrioxide, Gear oil blending, Polyalphaolephin-100, Polyisobutene Bull. Chem. Soc. Ethiop. 2017 , 31(1), 39-49. DOI: http://dx.doi.org/10.4314/bcse.v31i1.4

Influence of water contamination in gear lubricants on wear and micro-pitting performance of case carburized gears

PurposeWater can alter the performance of modern gear lubricants by influencing the flank load carrying capacity of gears significantly. The purpose of this paper is to investigate the influence of water contaminations in different kinds of base oils on the micro-pitting and wear performance of case carburized gears.Design/methodology/approachConcerning micro-pitting and wear, tests, based mostly on the following standardized tests, are performed on a Forschungsstelle fuer zahnraeder und getriebebau (FZG)-back-to-back gear test rig: micro-pitting short test Graufleckenkurztest (GFKT) according to DGMK 575 (screening test), micro-pitting test Graufleckentest (GT) according to FVA 54/7 (load stage test and endurance test) and Slow-speed wear test according to DGMK 377. To investigate the effect of water on the gear load carrying capacity dependent on different types of base oils, two polyglycol oils (PG1 and PG2), a polyalphaolefin oil, a mineral oil and an ester oil E are used. Each of these oils are common wind turbine gear oils with a viscosity ISO VG-220. Additionally, a manual transmission fluid with a viscosity of society of automotive engineers (SAE) 75W-85 is tested.FindingsConsidering the micro-pitting and wear performance, a significant decrease caused by water contaminations could not be detected. Regarding pitting damages, a generally negative influence was observed. This influence was differently distinctive for different base oil types. Especially non-polar lubricants seem to be affected negatively. The documented damages of the tooth flanks confirm this observation. While typical pitting damages appeared in test runs with polar lubricants, the disruption in test runs with non-polar lubricants was more extensive. Based on the experimental investigations, a general model of the damaging mechanisms of water contaminations in lubricants was derived. It is split into three partitions: interaction lubricant–water (effect of water on the molecular structure of base oils and additives), chemical-material-technological (especially corrosive reactions) and tribological influence (effect of water droplets in the contact zone). It has to be considered that the additive package of lubricants affects the influence of water contaminations on the flank load carrying capacity distinctively. An influence of water on the micro-pitting and wear performance in other than the given lubricants cannot be excluded.Originality/valueWhile former research work was focused more on the effects of water in mineral oils, investigations concerning different types of base oils as well as different types of damages were carried out within this research project.

Thermal and Rheological Properties of Industrial Mineral Gear Oil and Paraffinic Oil/CNTs Nanolubricants

Carbon nanotubes (CNTs) are used as a nanoadditive due to their unique properties and for improving the lubricant’s properties. In this research, the effect of CNTs in different concentrations (0.1, 0.5, 1 and 2 wt%) on kinematic viscosity, pour point, flash point and thermal conductivity coefficient as four quality parameters which are effective in the functionality of oil is evaluated and compared against the standard Mobil gear 627 and paraffinic mineral oils. The samples were tested according to ASTM D-445, ASTM D-97 and ASTM D-92 standards, respectively. The results indicated that the thermal conductivity, flash point, pour point and kinematic viscosity of nanolubricants with low concentration of CNTs improved with respect to the base oil. Dispersion of CNTs as additive has improved the lubricant properties and operational characteristics of Mobil gear 627 and paraffinic mineral oils.

Analyses of Tribological Properties of Castor Oil With Various Carbonaceous Micro- and Nano-Friction Modifiers

The present work investigates the tribological properties of castor oil with various carbonaceous friction modifiers (nano and microsize additives) assessed using four-ball tester as per ASTM D 4172 and ASTM D 2783. Castor oil has been chosen because of its high viscosity and ease of availability. Graphite, multiwalled carbon nanotube (MWCNT), and multilayered graphene are used as friction modifiers (FMs) in castor oil on weight percentage basis. Significant enhancements of tribological properties with a certain level of concentration of friction modifiers have been observed. The surface features of the tested balls were analyzed using a three-dimensional noncontact type profilometer, scanning electron microscope (SEM), and energy dispersive system (EDS). Decrease in surface roughness indicated better antiwear properties in case of nanofriction modifiers-based castor oil as compared to micrographite-based and neat castor oil (NCO). In order to assess the suitability of castor oil as a replacement for mineral oil, the results of castor oil samples are also compared with commercially available mineral oil. The tribological properties of castor oil are found to be competitive and generally superior to the mineral gear oil. The data generated are used to develop a neural network model to map the input–output correlation.

Axle gear oils: Friction behaviour under mixed and boundary lubrication regimes

The chemical composition of the axle lubricants and the tribological characteristics of the tribofilms are probed using measurement of friction, wear and film characteristics. Additives blended in the lubricants justified the frictional behaviour under mixed lubrication regime while surface texture and the tribofilm properties have substantiated the friction behaviour of the lubricant under boundary lubrication condition for high-lubricant temperature. This work will provide a comprehensive overview of two lubrication aspects and their effects on the lubricants friction behaviour through experimental tests using an EHD2 ball-on-disc apparatus.The effectiveness in friction reduction is shown depend on the ratio between what are defined as high- and low-friction species in the tribofilm.

English

This study characterized microbial strains isolated from diesel fuel samples collected from the tank of a generating set at the Institute of Research for Development in Pointe-Noire (Congo). Two bacterial isolates (G2 and G3) were distinguished by their color on agar plates and were characterized by their API 20E biochemical profiles and by 16S rRNA gene sequencing. The phenotypic properties of these isolates were consistent with their assignment to the genus Pseudomonas. Comparative 16S rRNA gene sequence analysis demonstrated that the G2 and G3 isolates were close relatives of P. aeruginosa strain GIM 32 and P. aeruginosa strain NV2, respectively, with 97% sequence identity. These two P. aeruginosa strains were able to grow in a mineral salt medium supplemented with 2% diesel fuel or SAE 90 gear oil as the only source of carbon. P. aeruginosa G3 showed faster growth and was able to emulsify diesel fuel (53%), gasoline (90%) and hexane (95%) more strongly than P. aeruginosa G2. Key words: Pseudomonas, emulsification index, diesel fuel, gasoline, hexane.

Viscosity Index Improver for Engine Oils: An Experimental Study

Engine oils are widely used for lubrication purposes in automobile and related industries. Viscosity Index (VI) improver has found its largest commercial applications as additives to engine oils. Examples are power steering fluid, aircraft piston engine oils, modern internal-combustion engines, turbine engine oils (stationary and aircraft), and industrial gear oils. Viscosity Index improvers are added in the lube oils to reach the desired Viscosity Index (VI). The enhancement of VI of lube oils (Servoneum 100, Servopress 68, Servomesh SP 220, and Servocut 335) by the addition of viscosity index improvers (Methylmethacrylate (MMA), Polybutadiene rubber (PBR), and Polyisoprene-cis) has been studied. VI of blended oils, made from the lube oils (Servoneum 100, Servopress 68, Servomesh SP 220, and Servocut 335) by the addition of MMA, PBR, and Polyisoprene-cis, has shown the potential to reach the maximum value. It has been found that the occurrence of maximum VI depends on the lube oil used and the type and concentration of viscosity index improver.

Synthesis of O-propylated canola oil derivatives using Al-SBA-15 (10) catalyst and study on their application as fuel additive

This research work provides insights on the application of Al-SBA-15 (10) as an efficient catalyst for the epoxide ring opening and O-propylation of unsaturated fatty acids in the canola oil and canola biodiesel. The objective of this study is to prepare potential lubricants from canola oil and canola biodiesel. The presence of unsaturation (>95%) in the oils is a limiting factor for a lubricant, and hence a two-step chemistry involving epoxidation followed by ring opening and O-alkylation has been employed to enhance the properties and make feedstocks promising as lubricants. Catalyst screening studies showed that Al-SBA-15 (10) catalyst is highly active in ring opening reactions with 1-propanol as a nucleophile. The physicochemical characterization showed that existence of Al3+ ions in Al-SBA-15 (10) promoted the desired transformation. Process optimization and statistical analysis were undertaken using CCD and RSM. Following are the optimal conditions at which 100% conversion of epoxidized oils to O-propylated biolubricants was achieved: temperature (100°C), epoxy to 1-propanol molar ratio (1:6), catalyst loading of 12% (w/w), and reaction time of 6h. A detailed investigation was presented in this article to optimize process conditions and to develop a plausible mechanism. Evaluation of physicochemical properties of O-propylated canola oil and O-propylated canola biodiesel showed their promising application as transmission gear oil and anti-wear hydraulic oils.

Chemical/Structural Modification of Canola Oil and Canola Biodiesel: Kinetic Studies and Biodegradability of the Alkoxides

Canola oil and canola biodiesel derived alkoxides are prepared in the present investigation through a series of structural modifications. Epoxidation of canola oil and canola biodiesel were carried out by hydrogen peroxide using IR-120 as an acidic catalyst. The alkoxylation of epoxidized feedstocks was promoted using 2-propanol and tert-Butyl alcohol in the presence of montmorillonite catalyst and optimum reaction conditions were obtained for complete epoxide conversion to alkoxylated products as follows: reaction temperature of 90 °C, epoxide to alcohol molar ratio of 1:6, and reaction time between 6 and 8 h. The products were identified with one- and two-dimensional Nuclear Magnetic Resonance (NMR) techniques, and the kinetic and thermodynamic parameters of the alkoxylation reactions were also investigated. The thermo-oxidative stability, rheology, biodegradability and lubricity properties of the prepared alkoxides were determined using American Society for Testing and Materials (ASTM) and American Oil Chemists Society (AOCS) standard methods. Structural modification of the feedstocks enhanced the significant properties for lubrication and exhibited their potential application as gear and engine oils.

Axle gear oils: Friction, wear and tribofilm generation under boundary lubrication regime

The internal friction torque measurements in Cylindrical Roller Thrust Bearings (RTB) lubricated with axle gear oils under boundary film conditions were performed using an axial rolling bearing test rig generating tribofilms. The X-ray photoelectron spectroscopy (XPS) was used to characterize the tribofilms formed on the bearing rollers and raceways. After the tests, wear debris were found on the oil samples which lubricated the surface of the roller bearing raceways for that surface topography measurements and oil analysis (ferrography) were mandatory to measure and to visualize the occurring wear. The results obtained indicate that axle gear oil formulations and their additive packages have got a significant influence in controlling roller bearing friction and wear under boundary film lubrication.

Development of a Stationary Axle Efficiency Test Stand and Methodology for Identifying Fuel Efficient Gear Oils for Military Applications - Part 1

Development of a Stationary Axle Efficiency Test Stand and Methodology for Identifying Fuel Efficient Gear Oils for Military Applications - Part 1

1 H-NMR with Multivariate Analysis for Automobile Lubricant Comparison.

Identification of suspected automobile-related lubricants could provide valuable information in forensic cases. We examined that automobile lubricants might exhibit the chemometric characteristics to their individual usages. To compare the degree of clustering in the plots, we co-plotted general industrial oils that were highly dissimilar with automobile lubricants in additive compositions. 1 H-NMR spectroscopy was used with multivariate statistics as a tool for grouping, clustering, and identification of automobile lubricants in laboratory conditions. We analyzed automobile lubricants including automobile engine oils, automobile transmission oils, automobile gear oils, and motorcycle oils. In contrast to the general industrial oils, automobile lubricants showed relatively high tendencies of clustering to their usages. Our pilot study demonstrated that the comparison of known and questioned samples to their usages might be possible in forensic fields.

Non-Dispersive Infrared Sensor for Online Condition Monitoring of Gearbox Oil.

The condition of lubricating oil used in automotive and industrial gearboxes must be controlled in order to guarantee optimum performance and prevent damage to machinery parts. In normal practice, this is done by regular oil change intervals and routine laboratory analysis, both of which involve considerable operating costs. In this paper, we present a compact and robust optical sensor that can be installed in the lubrication circuit to provide quasi-continuous information about the condition of the oil. The measuring principle is based on non-dispersive infrared spectroscopy. The implemented sensor setup consists of an optical measurement cell, two thin-film infrared emitters, and two four-channel pyroelectric detectors equipped with optical bandpass filters. We present a method based on multivariate partial least squares regression to select appropriate optical bandpass filters for monitoring the oxidation, water content, and acid number of the oil. We perform a ray tracing analysis to analyze and correct the influence of the light path in the optical setup on the optical parameters of the bandpass filters. The measurement values acquired with the sensor for three different gearbox oil types show high correlation with laboratory reference data for the oxidation, water content, and acid number. The presented sensor can thus be a useful supplementary tool for the online condition monitoring of lubricants when integrated into a gearbox oil circuit.