bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of lubricant on helicopter transmission efficiency
Authors: Coy John J. 
Published: July 2006

AbstractEfficiency tests were conducted using eleven different lubricants in the NASA Lewis Research Center's 500 hp torque regenerative helicopter transmission test stand. The test transmission was the OH58A helicopter main transmission. The mechanical power input to the test transmission was 224 kW (300 hp) at 6060 r/min. Tests were run at oil‐in temperatures of 335°K (180°F) and 372°K (210°F). The efficiency was calculated from a heat balance on the water running through an oil‐to‐water heat exchanger while the transmission was heavily insulated. The test lubricants were analysed for their physical and chemical properties. Data on pressure‐viscosity characteristics as well as friction data from LFW‐1 type testing were examined for possible correlation with the efficiency data.The following results were obtained. (1) Among the eleven different lubricants, the efficiency ranged from 98.3 to 98.8%, which is a 50% variation relative to the losses associated with the maximum efficiency measured. (2) for a given lubricant, the efficiency increased as temperature increased and thus as viscosity decreased. There were two exceptions which could not be explained on the basis of available data. (3) There was a reasonable correlation of efficiency with absolute viscosity (corrected for temperature and pressure in the contact). (4) Between lubricants, efficiency did not correlate well with absolute viscosity at atmospheric pressure. (5) Between lubricants, efficiency did not correlate well with calculated lubricant film forming capacity. (6) Bench type (LFW‐1) sliding friction and wear measurements could not be correlated to transmission efficiency and component wear. (7) The lubricants had no significant effect on the vibration signature of the transmission.
Solid lubricant additives for bismaleimide resin
Authors: Tewari U. S. , Sharma S. K. , Vasudevan P. 
Published: July 2006

AbstractBismaleimides are the addition type of polyimide resin. They are synthesized by reaction of diamino compounds with maleic anhydride. By varying the structure of the diamino compound it is possible to make various bismaleimides. This paper discusses improvement of the friction and wear properties of bismaleimide resin, by the addition of solid lubricant additives such as MoS2, graphite and PTFE.The bismaleimide tested has the following structure: magnified image On heating, bismaleimide cross links through its unsaturated bonds, thus producing a highly cross linked polyimide. The friction and wear measurements were done on a Plint friction and wear machine (pin on disc type), wherein polymer pins slid against a steel disc at different loads and speeds.The polymer itself had a high coefficient of friction, ranging from 0.3 to 0.6 and a higher wear rate. Solid lubricant additives helped in improving its friction and wear characteristics. The addition of graphite brought the coefficient of friction to 0.3 but wear remained high at high loads. Best results were obtained with additions to the resin of MoS2‐Sb2O3 and PTFE. Composites with MoS2‐Sb203 and PTFE had low coefficient of friction and low rate of wear, at low as well as at high loads. It appears that these solid lubricant additives transfer to the counterface, thereby reducing effective counterface roughness, hence reducing both friction and wear.
Fate of amine antioxidants during thermal oxidative ageing of neopentylpolyl ester oils
Authors: Zeman A. , Von Roenne V. , Trebert Y. 
Published: July 2006

AbstractThe main products of the thermal‐oxidative degradation of p, p'‐di‐tert‐ octyldiphenylamine, phenothiazine and 3,7‐di‐tert‐octylphenothiazine (DODPA/PTZ/DOPTZ) in pentaerythritol ester at 200°C were isolated and identified. Recombination o f aminyl radicals giving various dehydrodimers and dehydro‐trimers is obviously the dominating reaction in the primary stage of antioxidant depletion during ageing of inhibited ester oils. Minor degradation products include quinone imines, quinones, sulphoxides, phenoxazine and phenoxazone derivatives. Because of the complexity of the reactions product analyses are inevitably incomplete.
The effect of lubricant additives on friction and wear studies of polyphenylene sulphide
Authors: Tewari U. S. , Sharma S. K. , Vasudevan P. 
Published: July 2006

AbstractPolyphenylene sulphide is a polymer with good thermal stability and high crystallinity. This paper summarizes the results of friction and wear studies of polyphenylene sulphide and its composites made with conventional solid lubricants to ascertain the suitability of the material as a matrix for solid lubricant additives. The polymer itself has a high coefficient of friction. Wear rate increases with load and speed. Addition of solid lubricant additives helps in improving the friction and wear of the polymer. Composites with MoS2‐Sb2O3 and PTFE gave better results than composites made by the addition of graphite and MoS2 graphite. Wear rate of these composites increased with load and speed; but load and speed had little effect on friction.
Precision instrument oils
Authors: Venkataramani P. S. , Srivastava R. D. , Kalra S. L. , Srivastava H. C. 
Published: July 2006

AbstractPrecision instrument mechanisms require highly specialized oils. These stringent requirements limit the choice of lubricants to synthetic types only. In this paper the physico‐chemical and peformance characteristics of a watch oil developed by the authors have been discussed to show how it meets the basic requirements of watch oils, and compares favourably with widely accepted watch oils. Where the test methods and test limits are at variance with the specification IS: 1088–1975 for watch and clock oils, commentary is given and suitable recommendations for modifying IS: 1088–1975 are made.
New developments in the field of synthetic lubricants from natural sources
Authors: Cosmacini E. , Vertuani M. L. 
Published: July 2006

AbstractOils derivedfrom natural sources like vegetable and animal fats are constituted by a variety of triglycerides. The major drawbacks as compared to petroleum lubricants is poor stability under operating conditions, caused by (1) presence of β‐hydrogen in the glyceride radical; (2) unsaturation in acyl radicals, which is linked to hydroxide formation and oxidation stability; (3) linear structure of the fatty acid which has poor resistance to hydrolysis and emulsification.There are several reactions in oleochemistry by which the structure of triglycerides could be modified, and so liquids with good lubrication properties produced. These include hydrogenation, dimerization, alkylation, polyol formation and transesterification. This paper deals with the application of transesterfication for the modification of the glyceride structure into a lubricant. This permits preparation of a semisynthetic lubricant directly from natural glycerides. Molecular structure, molecular weight, polarity, rheological properties, thermal and hydrolytic stability of transesterification products are reported.
Energy conservation in stainless steel cold rolling applications
Authors: Ogura S. , Seki K. 
Published: July 2006

AbstractIn order to predict the performance of rolling oils in actual production mills, from tests in laboratory mills, the influence of various factors, such as shape factors work roll diameter (D), strip thickness (h1), operating conditions (reduction rate (r), peripheral velocity of roll (U0), strip velocity (U1)) and kinematic viscosity of the rolling oil (υ0) was investigated. A parameter RLI (Rolling Lubrication Index = u0(U0+U1)(1−r)(D/2h1.r)½) was found to be useful in predicting lubricating conditions in actual production mill applications.The coefficients of friction of mineral oils, some synthetic hydrocarbons including polybutene, and several kinds of additives were obtained from laboratory mills under the same condition of RLI value as that for finish rolling in actual production mills. With hydrocarbons, paraffins showed the lowest coefficient offriction, while aromatics exhibited a higher coefficient of friction, with naphthenes showing the highest.A high‐quality rolling oil was formulated using a combination of ester and paraffinic mineral oil. It is observed that this new oil can save 14% of energy consumed by a laboratory mill compared with conventional rolling oils. In production mills, nearly the same energy conservation level can be achieved.
Sxynthesis and properties of adamantane synthetic lubricants
Authors: Podehradskà J. , Vodička L. , Štěpina V. 
Published: July 2006

AbstractAdamantane hydrocarbons and esters have already been described in the literature. This paper examines the properties of two types of adamantane oils, tri‐ and tetrabutyladamantanes, and esters prepared from adamantyl methanols and aliphatic acids, and alkyladamantane carboxylic acids and aliphatic alcohols. The preparation, properties and in particular the electrical properties are presented.
Friction and wear studies of an internally lubricated polyetherimide composite
Authors: Bijwe J. , Tewari U. S. , Vasudevan P. 
Published: July 2006

AbstractPolyetherimide (PEI) is one of the latest generic high‐performance engineering thermoplastics. PEI (developed by General Electric (USA) under the trade name ULTEM) is an amber and amorphous polymer with a heat distortion temperature between those of polyarylate resin and thermally stable crystalline polymers such as polyether‐ether ketone (PEEK) and polyamideimide (PAI). It has excellent thermal, mechanical and electrical properties along with easy processability. In the work reported here, a wear‐resistant formulated composite supplied by GEC (ULTEM 4001) was selected for tribological investigations on a pin on disc machine under unlubricated conditions, against mild steel. Analysis of the composite revealed that this grade contained PTFE (13–15%), which is the most promising polymeric lubricant.A very low and stable frictional coefficient was observed against moderately finished surfaces. However, its specific wear resistance (⋍10−14 m3/Nm) was comparatively lower than that of fibre‐reinforced thermoplastics. The wear mechanism was found to be significantly dominated by the presence of PTFE. The friction coefficient was in the range of 0.2 and reduced to a still lower value (0.1) as the apparent contactpressure increased. Scanning electron microscopy was used to investigate the underlying wear mechanism. Film transfer of PTFE was observed to be the principal factor responsible for reduced friction.
Deuterated grease thickener
Authors: Conte Alfeo A. 
Published: July 2006

AbstractThe ‘Deuterium Isotope Effect’ was investigated as a means of further increasing the oxidation resistance of soap‐thickened greases utilized in miniature bearing applications. Using lithium stearate as a model compound, the bearing performance life and induction period for oxidation were determined on four different greases prepared from non‐deuterated and deuterated base oil and thickener. The expected increase in oxidation resistance and bearing performance life was observed for the deuterated base fluid; however, the use of a deuterated thickener did not provide any significant improvement. Details concerning the preparation of thickener and grease formulations and their properties are presented.
Water‐based hydraulic fluids containing synthetic components
Authors: Rasp C. R. 
Published: July 2006

AbstractThis paper explains the nature offire‐resistant, water‐based hydraulic fluids, and their applications, and gives comparisons with mineral oil‐based hydraulic fluids. The content of the different types of fluid is described, and the technical requirements for water‐based hydraulic fluids discussed. The chemistry of the synthetic thickeners of water, their thickening effect and shear stability, as well as their technical properties, are explained and compared. The construction and the mode of action of thickeners for hydraulic fire‐resistant fluids (HFAS) or viscous high‐water‐based fluids (VHWBF) are detailed, and the physical chemistry of these hydrophilic‐hydrophobic thickeners, which form microemulsions in water, is considered in interaction with emulsifying agents. In this case laser‐light scattering correlation spectroscopy is shown to be helpful.
Thermal stability of synthetic oils in aviation applications
Authors: Koch B. 
Published: July 2006

AbstractThe thermal decomposition of selected synthetic base fluids has been investigated. The effects of temperature and time on the rate and extent of thermal degradation were studied in a modified steel bomb test device. The effects of chain length and branching are important factors in the thermal stability of hydrocarbons and similar fluids. In order to overcome the 350°C limit of thermal stability, other classes of chemical have to be used.
Development of a meta‐stable semi‐synthetic lubricant for cold rolling of steel
Authors: Mahanti S. , Bhatta A. K. , Biswas R. N. , Bhatia J. , Singh S. N. 
Published: July 2006

AbstractA semi‐synthetic meta‐stable oil system for cold rolling of steel was developed as a substitute for a mineral oil based ‘stable emulsion’‐type soluble oil. The developed oil system, comprising a ‘coating oil’ for post‐pickling application and a ‘rolling oil’ for the rolling operation, was tested in the laboratory and subsequently subjected to extensive field trials in an integrated steel plant. Use of the developed oil system resulted in 25–50 per cent lower roll loads and 30–50 per cent reduction of inter‐stand tensions compared with the mineral oil‐based ‘stable emulsion’. It was also possible to increase the ‘strip reduction ratio’ and input coil width with the use of the newly‐developed oil. Overall performance of the new semi‐synthetic oil was found to be far superior to that of the mineral oil based ‘stable emulsion’.
Influence of cutting fluids on surface finish of holes drilled into aluminium 390
Authors: Leep Herman R. 
Published: July 2006

AbstractThe primary objective of this research was to compare the surface finish resulting when using a semi‐synthetic cutting fluid to that of a premium soluble oil. The secondary objective was to determine the effects of drill diameter, cutting speed, and fluid concentration on surface finish.The surface measurements were made on the walls of 6.350 and 9.525 mm lind holes drilled 25.4 mm into aluminium 390. Each cutting fluid was introduced using a flood application. Additional factors in the experimental design for each cutting fluid included two levels of cutting speed and two levels of fluid concentration.Variations in drill diameter, cutting speed, and the interaction between these factors were significant with respect to surface finish for both the semi‐synthetic fluid and the soluble oil. Fluid concentration for the semi‐synthetic fluid also had a significant effect on the surface finish. The surface finish produced while using the semi‐synthetic fluid was approximately the same as that with the soluble oil.
Analysis and quality control of aviation turbine oils
Authors: Bartl P. , Seinsche K. 
Published: July 2006

AbstractA method is described in which capillary gas chromatographic data from aviation turbine oils are processed by methods of pattern recognition based on the chemometrics systempackage ‘Ein*Sight’. It allows an automatic, objective and quantitative comparison of the base oil components of production batches. This application can be used to advantage in a control scheme based on analytical data.
Optimal preparation conditions for some diester based synthetic lubricants
Authors: El‐Magly I. A. , Nasr E. S. , El‐Samanoudy M. S. 
Published: July 2006

AbstractIn this paper, work is reported on the esteriflcation of various materials, where di‐2‐ethythexyl esters of succinic, adipic, azelaic and sebacic acid were prepared. Water produced by the reaction was separated continuously and the reaction progress was followed up by measurement of the acid content. Factors affecting the esterification were studied and the optimal conditions for conversion of about 92% to 95% (by weight) were found to be: temperature — 179°C; molar ratio of add to alcohol — 1:2.4; catalyst concentration — 3% (by weight) based on acid; agitation rate — 350 r/min.
The application of synthetic fluids to automotive lubricant development: Trends today and tomorrow
Authors: Coffin P. S. , Lindsay C. M. , Mills A. J. , Lindenkamp H. , Fuhrmann J. 
Published: July 2006

AbstractEngineering design of the internal combustion engine is under a constant state of evolution which has been driven by many factors. These design changes have led to higher performance requirements from the lubricant, e.g. greater resistance to thermal and oxidative degradation, improved deposit and sludge control, and increased control of volatility. Mineralbased lubricants have traditionally proved successful for the vast majority of automotive applications. The current advances have stretched such products to the limit of their capabilities. In such areas, it has been found that synthetic lubricants offer benefits far outweighing their higher costs, providing clearcut performance benefits for the modern generation of higher‐performance vehicles. The current state of the art is reviewed from both application and chemical standpoints, and future trends are projected in the light of ongoing developments.
Synthetic lubricants in cold strip rolling
Authors: Lenard J. G. 
Published: July 2006

AbstractThe embedded‐pin technique is used to monitor the variation of the interfacial forces during cold rolling of aluminium slabs. The results confirm earlier conclusions, indicating that the frictional coefficient is a strong function of the process and material parameters. Coefficient of friction values deduced from forward slip measurements are close to the present data, confirming that in spite of several drawbacks of the experimental technique, it can yield very useful results. Lubricants are shown to reduce the loads on the rolling mills in a significant manner.
Improvement of antioxidation and antiwear properties of polyalphaolefin oils
Authors: Shkolnikov V. M. , Zvetkov O. N. , Chagina M. A. , Kolessova G. V. 
Published: July 2006

AbstractPolyalphaolefin‐based lubricating oils were tested on a four‐ball tester, and in a stability test, with antiwear and antioxidant additives of different types, along with other (petroleum and alkylbenzene) base oils and additives. Antioxidant additives for PAOs essentially influence their thermo‐oxidation stability. It was found that binary inhibitors increased thermo‐oxidation stability effectively. In the antiwear tests, the addition of additives to PAOs sharply decreased wear scar diameters. A significant difference was observed in the action of small concentrations of antiwear additives as between PAO, alkylbenzene and mineral oils. Explanations of this behaviour are put forward.
Precision bearings and their tribological simulation
Authors: Stehr W. 
Published: July 2006

AbstractReliable laboratory simulation of the tribological conditions that lubricated sliding bearings face in the field requires the use of computer assisted test procedures. The example of lubricated plastic bearings given here illustrates the use of relational database systems combined with automated data analysis, and shows its relevance for practical applications.To predict the functioning of lubricated platic bearings, a multiple of test procedures and laboratory methods are necessary due to the large variety of synthetic lubricants and the multiple of plastics. Each test procedure generates a considerable amount of individual data. From these data, the information relevant for each particular application must be extracted. This procedure can be speeded up by using a database, and indeed some of it is only possible with the use of a database. This database acts as the central place for data collection. By using specific commands, with actual parameters acting as filters, the necessary information can be retrieved. The efficiency of tribological testing and its immediate relevance for the field is thereby greatly enhanced.
Synthetic lubricants for air cooled two cycle engine oils: Effect of esters on lubrication and tribological properties
Authors: Moura D. , Légeron J.‐P. 
Published: July 2006

AbstractThis paper reports the development of an air‐cooled two‐stroke engine lubricant using esters as synthetic base stocks, and performance additives. The viscosimetric and terminological properties as well as the performance in two‐cycle gasoline engines are described in comparison with standard lubricants. It is shown that the use of suitable esters can make possible the formulation of high performance lubricants for the severity of use.
A study of greases based on polyureas
Authors: Liangsen Xie , Hui Li 
Published: July 2006

AbstractThis paper illustrates the thickening effects of diureas and tetraureas formed from monoamines, diamines and diisocyanates on the mineral oils of different viscosity, and on the esters and polysiloxanes of different structures. It also reviews the properties and applications of such greases based on polyureas.
A study of the viscosity‐temperature relationship of synthetic lubricants
Authors: Yang‐Wu Zhang 
Published: July 2006

AbstractVarious workers have developed different viscosity ‐temperature relationships for fluids for many years. These relationships are suitable for a narrow temperature range, but they are unsuitable over the wide temperature ranges of synthetic lubricants. This paper describes a modified ASTM 0341 viscosity‐temperature relationship developed by a least‐squares treatment of large amount of available experimental viscosity data for synthetic lubricants. The modified relationship reads:

.The relationship can adequately describe viscosity‐temperature characteristics of synthetic lubricants over a wide temperature range. The relationship was examined for various synthetic lubricants. It was found capable of correlating the available experimental viscosity data with an average absolute error of less than 2% between calculated values and experimentally determined values over the temperature ranges studied for 14 synthetic lubricants.
A novel family of traction fluids deriving from molecular design
Authors: Dare‐Edwards M. P. 
Published: July 2006

AbstractAn investigation has been undertaken into the fundamental molecular design features that may be seen to correlate with high traction coefficients of lubricants operating under elastohydrodynamic conditions. With the assistance of computer‐aided molecular mechanics modelling, a novel family of fluids has been designed which display excellent tractional performance. Prospects for the further development of these modelling techniques and also the practical usage of the designed fluids are discussed.
Comparison of synthetic aromatic oil and crude oil resistances against the influence of nuclear radiation
Authors: Kostolányi Peter , Szücs Ladislav , Ruman Ján 
Published: July 2006

AbstractThe use of lubricants in conditions of radiation, as in nuclear power installation, poses certain problems for the stability of the lubricant. These include (1) changes in viscosity, (2) evolution of gases, (3) in air, accelerated oxidation, (4) secondary effects such as separation of additives and demulsibility deterioration. In this paper are reported the results of experiments on changes in kinematic viscosity and acid base number of mineral base oils and a synthetic oil.