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Article
Publication date: 1 August 2005

Yajun Ma, Wancheng Zhao, Shenghua Li, Yuansheng Jin, Yucong Wang and Tung C. Simon

Improved fuel economy, lower emission and longer durability are the major developing trends of engine oils. Aims to describe further research on the friction coefficient…

Abstract

Purpose

Improved fuel economy, lower emission and longer durability are the major developing trends of engine oils. Aims to describe further research on the friction coefficient of engine oils.

Design/methodology/approach

The lubricating durability D was defined based on definition of three characteristic points Pd, PS, Pi and three key time lengths Td, Ts, Ti. Two kinds of engine oils, respectively, belonging to GF‐2 and GF‐3 categories, were selected as samples to compare their lubricating durability.

Findings

Test results indicate the GF‐3 oil has much better lubricating durability than GF‐2 oil. With investigation of the topography and chemical composition changes of wear tracks along with the tribotests' time extending, the meanings of three characteristic points were discussed. Analysis indicates much better tribofilm, formed by the synergistic effect of Ca‐containing detergent with MoDTC/ZDTP in GF‐3 oil, is the major factor resulting in GF‐3 oil's longer lubricating durability.

Originality/value

Provides further research on lubricating durability, which is important for engine oil change and maintenance, as well as decreased cost and pollution to the environment, and improved energy conservation.

Details

Industrial Lubrication and Tribology, vol. 57 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 20 January 2022

Xiuheng Zhang, Ningning Hu, Tianchi Chen and Songquan Wang

This study aims to prevent the sharp decline in the load-carrying capacity of lubricating oil film under harsh conditions of abrupt changes in friction interface…

Abstract

Purpose

This study aims to prevent the sharp decline in the load-carrying capacity of lubricating oil film under harsh conditions of abrupt changes in friction interface temperature, which is a major challenge in lubrication technology.

Design/methodology/approach

In this paper, we synthesized a series of silver pyrazole methylpyridine complexes containing a high metal concentration and minimal supporting organic ligands (complex 1 [Ag(LMe)]2(BF4)2, complex 2 [Ag(Li-Pr)n](BF4)n and complex 3 [Ag(LMe)(NO3)]2). The thermal decompose behavior of as-prepared silver complex was investigated by thermogravimetric analysis and X-ray photoelectron spectrometry (XPS). Four-ball friction testers were used to evaluate the friction and wear properties of lubricating oil in the temperature ranges associated with the operation of modern heavy machinery.

Findings

The complex decomposed silver particles at high-temperature, which could fill the pits on the friction surface, change the wear form of the friction pair and reduce the roughness of the friction surface. Reduction in both friction coefficients and wear scar diameters was obtained by adding silver complexes in oil. The lubricating oil, with the additive content of 1.5 Wt.%, has the best tribological performance, moreover, the lubricating performance of the silver complexes in oil were correlated with their concentration and thermal decomposed temperatures, respectively.

Originality/value

As a result, a series of silver pyrazole methylpyridine complexes as oil additives can support friction and wear reduction under abrupt high-temperature conditions are intended to be a controllable backup lubricant additive.

Details

Industrial Lubrication and Tribology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 December 1957

Previous work has suggested that the adhesion between oil and metallic surfaces of an engine could be an important factor in determining crankcase cleanliness. It can be…

Abstract

Previous work has suggested that the adhesion between oil and metallic surfaces of an engine could be an important factor in determining crankcase cleanliness. It can be shown that it is only necessary to measure the spreading pressure of an oil on metal in order to get a direct measure of the work of adhesion, Surface tensions of lubrictaing oils vary very little and it can be assumed that the critical film pressure (C.F.P.) obtained with a given apparatus is an acceptable measure of the work of adhesion as well as of the spreading pressure. Oils of similar properties may vary tenfold in their C.F.P's. The addition of additives influences the spreading pressure, the largest increments in C.F.P. being given by dispersant and detergent additives.

Details

Industrial Lubrication and Tribology, vol. 9 no. 12
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 6 December 2018

Zhen Yan, Dong Jiang, Xiaoming Gao, Can Zhang, Ming Hu, Dapeng Feng, Jiayi Sun, Lijun Weng and Chao Wang

This paper aims to study the tribological behavior of the WS2/oil-impregnated porous polyimide (PPI) solid/liquid composite system, in which both PFPE (perfluoropolyether…

Abstract

Purpose

This paper aims to study the tribological behavior of the WS2/oil-impregnated porous polyimide (PPI) solid/liquid composite system, in which both PFPE (perfluoropolyether) and SiCH (silahydrocarbons) oils with different hydrocarbon chains were used, respectively. Lubricating mechanism of the composite system was also explored.

Design/methodology/approach

The tribological behaviors of the WS2 films against the PPI cylindrical pins before and after immersing oil were evaluated under different loads by a reciprocating-type ball-on-disc tribometer.

Findings

The composite system exhibited the low and stable friction coefficient after the running-in stage, and the lubricant oil played a positive effect. It was found that the WS2/PFPE composite system exhibited more excellent lubricating property, although sole SiCH far exceeds PFPE in lubrication. The abnormal phenomenon mainly resulted from the influence of the oil amount. XRD results on the wear track surfaces indicated that PFPE and SiCH oils with different hydrocarbon chains were likely to preferentially adsorb to the edge plane and basal plane of the WS2 crystals, respectively.

Originality/value

In previous studies, liquid lubricants were directly dripped or spin-coated on the solid lubricant surface. Based on its potential advantage in application, the tribological behavior and mechanism of the solid lubricating film/oil-impregnated PPI composite system were investigated in this study.

Details

Industrial Lubrication and Tribology, vol. 71 no. 3
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 February 2004

Ertugˇrul Durak

Today's worries and doubts related to the use of mineral oils increased because of the worldwide interest in environmental issues. This issue has increased the use of…

Abstract

Today's worries and doubts related to the use of mineral oils increased because of the worldwide interest in environmental issues. This issue has increased the use of vegetable oils as an alternative lubricating oil candidate, environment‐friendly lubricant and their additives. In this study, rapeseed oil (RSO) in different concentrations, 1, 2, 3, 5, 10, 20, 30, 40, 50 (by volume percent), was added to base oil to obtain a lubricating oil candidate. Turkish originated RSO was studied as an additive candidate in this paper. The study of the effect of additives in mineral oils was carried out using a specially designed experimental system to compare lubricating oil candidates and high temperatures using engine journal bearings under statically loaded.

Details

Industrial Lubrication and Tribology, vol. 56 no. 1
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 13 June 2016

Doğuş Özkan, M. Barış Yağci, Özgür Birer and Hakan Kaleli

This study aims to evaluate and compare by 100 hours engine bench tests the tribological performances of two types of lubrication oils, which were sulfur-based, boron…

Abstract

Purpose

This study aims to evaluate and compare by 100 hours engine bench tests the tribological performances of two types of lubrication oils, which were sulfur-based, boron succinimide-containing antiwear package (NP-3) oil and conventional zinc dialkyldithiophosphate (ZDDP)-containing (R-1) oil.

Design/methodology/approach

The tribological performances of the oils were evaluated in three main contexts, including engine tests, physical/chemical changes and surface analysis.

Findings

Results showed that NP-3 lubrication oil, which was environment- and catalyst-friendly, can be an alternative lubrication oil with its tribological performance due to similar antiwear characteristics with the ZDDP.

Originality/value

Attempts to develop catalysis- and environment-friendly antiwear additive packages have not presented popular or commonly used ZDDP-free products for the vehicle industry. This study presents tribological characterization of a newly developed ZDDP-free lubricating oil by engine bench tests.

Details

Industrial Lubrication and Tribology, vol. 68 no. 4
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 1 August 1999

Radoslav Rakić

The main role of the gears is to ensure smoothness and noiseless service, required power transmission, precision of processing, necessary degree of efficiency and so on…

Abstract

The main role of the gears is to ensure smoothness and noiseless service, required power transmission, precision of processing, necessary degree of efficiency and so on. Lubrication is of significant importance to the protection of gears from tribological processes which cause failure of gears. The aim of this study is to investigate the influence of lubricating oils on the reliability of gears. The experimental investigation of the influence of some industrial oils on the tribological behaviour of gears of machine tools has been carried out at a metalworking factory. The paper presents the following: the classification of industrial oils for gears; the flow‐chart of the choice of the industrial oil for gears; the analysis of the symptoms and the causes of failure to gears; the reliability curves of gears in the function of tribological properties of lubricating oils under the operating conditions of investigation here presented. The reliability of gears was found to be affected by both the type of lubricating oil and the viscosity grade.

Details

Industrial Lubrication and Tribology, vol. 51 no. 4
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 9 April 2018

Guijun Wang and Guoying Zhang

This paper aims to overcome the defect that the traditional clustering method is excessively dependent on initial clustering radius and also provide new technical measures…

Abstract

Purpose

This paper aims to overcome the defect that the traditional clustering method is excessively dependent on initial clustering radius and also provide new technical measures for detecting the component content of lubricating oil based on the fuzzy neural system model.

Design/methodology/approach

According to the layers model of the fuzzy neural system model for the given sample data pair, the new clustering method can be implemented, and through the fuzzy system model, the detection method for the selected oil samples is given. By applying this method, the composition contents of 30 kinds of oil samples in lubricating oil are checked, and the actual composition contents of oil samples are compared.

Findings

Through the detection of 21 mineral elements in 30 oil samples, it can be known that the four mineral elements such as Zn, P, Ca and Mg have largest contribution rate to the lubricating oil, and they can be regarded as the main factors for classification of lubricating oil. The results show that the fuzzy system to be established based on sample data clustering has better performance in detection lubricant component content.

Originality/value

In spite of lots of methods for detecting the component of lubricating oil at the present, there is still no detection of the component of lubricating oil through clustering method based on sample data pair. The new nearest clustering method is proposed in this paper, and it can be more effectively used to detect the content of lubricating oil.

Details

Industrial Lubrication and Tribology, vol. 70 no. 3
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 13 February 2007

Zbigniew A. Szydlo

To provide information on the distribution of oil deposition inside the pipe conducting oil mist used for lubricating purposes and to show resulting variations of oil/air ratio.

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Abstract

Purpose

To provide information on the distribution of oil deposition inside the pipe conducting oil mist used for lubricating purposes and to show resulting variations of oil/air ratio.

Design/methodology/approach

The model of an industrial pipeline has been assembled ranging more than 100 m away from the oil mist source, equipped with devices collecting oil deposited inside the pipes. Other tests were performed in stands constructed as parts of pipes coiled in helical form. Long time experiments with continuous oil mist flow enabled to achieve calculable results.

Findings

The quantitative results obtained in experimental investigation on the reduction of oil/air ratio in an oil mist header system show that considerable differences of the oil/air ratio may be observed in a typical long pipeline. Possible consequences of oil deficiency on lubrication of remote mechanisms are presented in the case study. Results of tests are shown in diagrams and tables. These results may be useful for correction of design calculations procedures.

Research limitations/implications

Tests have been made on the basis of one kind of the oil atomized in typical condition and conveyed with steady flow through the piping of rather simple geometry. However, there are other factors affecting oil droplets deposition and the most influencing are probably: the flow velocity/pipe diameter factor, oil atomization characteristics and the geometry of the oil mist piping.

Practical implications

The research has shown dramatic decrease of oil content in the long distance systems that may result in poor lubrication of remote mechanisms or over lubrication of those located close to the oil mist generator. It should be taken on account in calculation of oil mist demand to particular lubrication points.

Originality/value

Presented tests have been carried in the scale and flow parameters very close to those applied in industry. Thus, the results are reliable and could be very useful both for designers and the practitioners of centralized oil mist systems.

Details

Industrial Lubrication and Tribology, vol. 59 no. 1
Type: Research Article
ISSN: 0036-8792

Keywords

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Article
Publication date: 17 August 2018

Daoyi Wu, Yufu Xu, Lulu Yao, Tao You and Xianguo Hu

This paper aims to study the upgradation of the lubricating performance of the renewable base oil , and to study the tribological behavior of graphene oxide (GO) sheets…

Abstract

Purpose

This paper aims to study the upgradation of the lubricating performance of the renewable base oil , and to study the tribological behavior of graphene oxide (GO) sheets used as lubricating additives in bio-oil for iron/steel contact.

Design/methodology/approach

A multifunctional end-face tribometer was used to characterize the friction coefficient and wear loss of the tribosystem under different lubricants.

Findings

The experimental results show that GO sheets with small size benefit lubricating effects and the optimal concentration of GO sheets in bio-oil is 0.4-0.6 per cent, which can form a complete lubricating film on the frictional interfaces and obtain a low friction coefficient and wear loss. Higher concentration of GO sheets can result in a significant aggregation of the sheets, reducing the content of the lubricating components in the bio-oil, which results in the increase in friction and wear; at this stage, the main wear pattern was ascribed to adhesive wear.

Practical implications

These results show a promising prospect of improving the tribological performance of renewable base oil with the introduction of GO sheets as additives.

Originality/value

No literature has covered the tribological behaviour of GO sheets in bio-oil. This study contributes to accelerating the application of bio-oil.

Details

Industrial Lubrication and Tribology, vol. 70 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

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