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Due to high speeds, heavy loads, large slide-to-roll ratios (SRR) and other variable operating conditions, some rolling bearings that have been working in harsh conditions may experience flash temperatures in the contact area, which may result in early damage like smearing and then affect service life. This study aims to investigate the flash temperature phenomenon of rolling bearings through theoretical and experimental analysis.

A technology for measuring temperature distribution in rolling ball on disk contact under lubrication was developed. The test-rig can simulate the ball bearing contact. The effects of working conditions such as entrainment speed, load, SRR and lubricating oil viscosity on the flash temperature were investigated.

The results of the theoretical calculation and experiments indicate that the parameters promoting the reduction of film thickness in elastohydrodynamic lubrication are always related with the number of flash points, even film thickness reduced to mixed lubrication. The flash temperature is easier to happen in conditions of high SRR, heavy load, slow entrainment speed and low viscosity oil.

This work conducts an experimental study on the flash temperature phenomenon, providing a test technology for bearing lubrication and failure investigation.

This author has opted into Transparent Peer Review available at: https://publons.com/publon/10.1108/ILT-04-2023-0104

A series of articles explaining in simple language the fundamentals of Lubrication

Scalable Vector Graphics (SVG) is an XML‐based vector graphics standard developed by the World Wide Web Consortium. The National Archives of Singapore recently launched an online virtual exhibition, Colours in the Wind, which was developed using Macromedia Flash, the most widely used format for animated and interactive vector‐based Web content. The current work reports on the experiences in developing an SVG‐based version of this exhibition as well as the exploration of SVG's potential for developing future virtual exhibitions as an alternative to Flash. Observations from the SVG effort are discussed together with descriptions of techniques used and the limitations and problems that SVG poses to developers. A comparative study involving the usability features of the Flash and SVG versions of the virtual exhibition is also described. Results indicate that users are positive towards SVG and suggest the viability of the technology as a development platform.

The paper aims to study the effects of introducing oxypropyl segments into the trimethylolpropane (TMP) esters along with lowering the linear chain length from C₅‐C₉ to C₅‐C₆ on the properties of base lubricants.

Various amounts of oxypropylene segments were introduced into the TMP skeleton and obtained polyols subsequently esterified by pure C₅‐, C₆‐, and mixture of C₅‐C₆‐ aliphatic monocarboxylic acids of normal structure (SFAc mixture).

Introducing oxypropylene segments into TMP skeleton, along with lowering the carboxylic acid chain length from C₅‐C₉ to C₅‐C₆, ester base lubricants obtained improved mechanical and wear preventive characteristics.

Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.

The obtained materials have high boiling points under reduced pressure (2 mmHg). Producing higher vacuums will make the distillation process easier.

This paper fulfils detail information on the experimentally preparation of oxypropylated TMPs as synthetic base lubricants. The synthesized compounds showed improved properties such as high viscosity at 100°C, low pour point, high flash point, and totally excellent viscosity‐temperature properties than simple TMP esters and some literature reported ester base lubricants.

To prepare semi‐synthetic oils satisfying the classification API SF/CC and SAE 10W30 from mineral base oils derived from high paraffinic petroleum, synthetic alkylbenzenes base oils, and suitable additives.

The mixtures of base mineral oils of deep hydro‐isomerization derived from high‐paraffinic petroleum (viscosity at 100°C is 12.5 cSt) and the mixtures of the synthetic alkyl aromatics oils with the naphthenic components (viscosity at 100°C of 8.0 cSt) were used as base oil. viscosity‐temperature properties, pour points, and flash points were modified by mixing of suitable additives. Octan M‐1, Octan M‐2, Octan M‐3, and Octan M‐4 oils were obtained by application of suitable additives into the prepared base oils B‐C. In order to get the SAE 10W30 requirements the viscous additive was added (0.4‐0.6 mass percent) to prepared base oils. For obtaining the API/SF/CC grade oils, package additive (Hitec 9229) additive was added (4.7 mass percent) to the mixture. The oil (Octan M‐1) was tested in the engine of Mercedes‐Benz model 230 car and positive results over 20,000 km running.

It was observed that, viscosities and pour points change linearly as the mass percent of alkylbenzenes the in the base oil mixture is changed. This realizes the possibility of the creation of semi‐synthetic motor oil of desired properties in the case of lack of other low‐viscosity synthetic component such as poly‐á‐olefins, diester and polyester oil. The obtained oils are useful for service in relatively mild climatic conditions (average temperature of the winter period −15 to −30°C).

The obtained oils cannot fully satisfy the requirements of the engines by pour point and low‐temperature characteristics in the absence of additives.

Because of complexity of obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.

Details practical information on preparation of four semi‐synthetic oils satisfying the classification API SF/CC are reported.

IN THE concluding paragraphs of the preceding section (October issue) a brief mention was made of grease tests of a special type by which service behaviour under certain conditions—at high or low temperature for example—could be forecasted. This sort of lubricant testing which attempts to simulate actual service conditions, but accelerates them, is a typical feature of today's practice both in the oil industry and also in the laboratories of lubricant users. In fact, so far as lubricating greases are concerned, it was users (in this particular instance the manufacturers) of ball and roller bearings, who were the pioneers in the field. This is understandable, for the overwhelming majority of anti‐friction bearings are grease lubricated and before the maker can give his recommendation for any particular grade, he must make sure that it will give satisfactory service under the anticipated operating conditions. Certain test machines, which naturally incorporate ball or roller bearings, have become so well known that they have been adopted as official standards in some countries.

INDIRECT or secondary heating systems are systems in which a primary source of heat—fuel oil, gas or electricity—is used to heat a fluid that transfers heat to the point of application, where a second heat transfer takes place.

The purpose of this paper is to prepare metallocene polyalphaolefin 8 (mPAO8) by the oligomerization of olefin from coal with metallocene catalyst system and compare it with commercially available polyalphaolefin 8 (PAO8) from Chevron.

Molecular structures, component and mass were determined by nuclear magnetic resonance spectroscopy, gas chromatography and gel permeation chromatography, respectively. The physico-chemical properties, including Noack volatility, viscosity index and elemental analyses, were studied. The oxidative stability was evaluated by pressurized differential scanning calorimetry, whereas the thermal stability was studied by thermo-gravimetric analysis.

The produced mPAO8 consisted of a large part of tetramer, pentamer and a small part of trimer and hexamer. Additive T501 significantly improved the oxidation stability of PAO8 from Chevron and the synthesized mPAO8. Both samples had similar properties, such as oxidative stability, additive response, pour point and Noack volatility loss. But mPAO8 possessed a higher thermal stability, better viscosity index and flash point than PAO8. Therefore, the mPAO8 prepared by the oligomerization of olefin from coal could be used as base oil for lubricant development.

The mPAO8 base oil was successfully prepared by successive carbon numbers and shows similar properties with commercially available PAO8 products from Chevron. The findings can cover the shortage of the synthesis lubricants market in China.

IT IS OF INTEREST TO RECALL THAT while B.S. 210, issued in 1924 was the first British Standard covering mineral lubricating oils, this was not the first time that the British Standards Institution had paid attention to the petroleum industry. Earlier, in 1921 and 1923 motor spirit and benzol had been covered by B.S.121 and B.S.135 respectively. Shortly after B.S.210, further attention was paid to this field in general by the issue, in 1927, of B.S.148 and in 1929 of B.S.188. B.148 dealing with insulating oils for electrical purposes, has subsequently been revised but in the main is little changed even today. B.S.188 deals with the determination of viscosity in absolute units, a matter closely related to lubricants and of obvious interest to those engaged in lubricant testing and manufacturing control. It is in the process of revision and enlargement and a draft has just been issued for comment.

The more frequently an engine oil is changed, the more the overhaul life of the engine is extended but with an increase in the cost both of the oil and of the oil drain services. If engine oil is changed less frequently the associated costs will decrease. In order to find the optimum drain interval, it is necessary to establish the relationship between the cost of the oil and oil drain services and the cost of more frequent overhauls. Presents an investigation into the degradation of a proprietary lubricant marketed in Turkey, and the wear rate of a petrol engine driven in urban traffic. Lubricant samples were examined approximately every 2,000km for deterioration of the lubricant and evidence of wear of the engine components. From the experimental results, determines the optimum oil drain period of the engine.