Industrial Lubrication and Tribology

Mufti, Riaz Ahmad ; Zahid, Rehan ; Qureshi, Farrukh ; Aslam, Jawad

doi: 10.1108/ILT-07-2013-0076pmid: N/A

Purpose – The purpose of this paper is to understand the effect of engine operating conditions and lubricant friction modifier on direct acting tappet rotation. In this research work, novel method of measuring engine tappet rotation speed has been developed. The technique is so novel. It allows the measurement on real production engine with no modification to the engine tappet bore. Also, In this paper, the effect of engine operating conditions and the effectiveness of friction modifier on tappet rotation is reported. Design/methodology/approach – For the very first time, for the purpose of measuring follower rotation in a real production engine, a 4 × 6 mm2 electronic chip called Gradiometer is mounted outside the tappet housing, allowing the monitoring of tappet rotation speed without the need to machine a hole in the tappet bore. This novel technique is adopted on Mercedes Benz OM464 engine to study the effect of engine conditions and lubricant chemistry on tappet performance. Findings – The main outcome of this research work is the development of novel method of measuring tappet rotation. Also, during the experiments, it was revealed that although friction modifiers help in reducing friction at the cam/tappet interface, they can also adversely affect the tappet rotation speed. Originality/value – The novel technique developed in the research work is one of the most cost effective and simple to use. Researches can adopt the technique to study the tribological performance of direct acting tappet on real production engine. Researches acknowledge the effectiveness of friction modifiers in valve train but its effect on rotation which plays a key role in the component durability has not been the focus of most of the researches mainly due to lack of effective techniques.

Kiran, TS ; Prasannakumar, M ; Basavarajappa, S ; Viswanatha, BM

doi: 10.1108/ILT-08-2013-0090pmid: N/A

Purpose – The purpose of the paper is to study the dry sliding wear behavior of as-cast and heat-treated zinc-aluminum (ZA-27) alloy, reinforced with silicon carbide and graphite particles. Design/methodology/approach – The alloy and composite samples were prepared with stir casting technique. Heat treatment was carried out for samples at a temperature of 370°C followed by quenching in water at room temperature. Subsequently, the heat-treated samples were aged at 180°C and quenched in water at room temperature. The wear tests were carried using pin-on-disc apparatus at room temperature at different applied loads, sliding speed and sliding distance. Findings – The wear volume loss of as-cast samples was more compared with heat treated samples. Composites exhibited improved wear resistance than base alloy. Originality/value – Hybrid metal matrix composites with heat treatment has exhibited superior wear behavior in dry sliding conditions.

Li, Pengju ; Zhu, Yongsheng ; Zhang, Youyun ; Yue, Pengfei

doi: 10.1108/ILT-07-2013-0081pmid: N/A

Purpose – This paper aims to present the theoretical and experimental investigation of the temperature of high speed and heavy haul tilting pad journal bearing. Design/methodology/approach – The bearing is 152.15 mm in diameter with three slenderness ratios (L/D) and three clearance ratios. The equations that govern the flow and energy transport are solved by the finite difference method, and the experimental tests are conducted in a test rig of high speed and heavy haul tilting pad journal bearing. The shaft speed ranges from 3,000 to 16,500 r/min (the highest linear-velocity equals 131.4 m/s), and the three static loads are 10, 20 and 30 KN. Findings – The comparisons between numerical results and experimental results show better correlations. It is shown in the theoretical and experimental results that the temperature increases with static load and shaft speed and decreases with clearance ratio and L/D. Originality/value – The theoretical models presented in this paper can be used to predict the temperature of tilting pad journal bearing when the shaft’s linear velocity is up to 130 m/s.

Maliar, Tatjana ; Achanta, Satish ; Cesiulis, Henrikas ; Drees, Dirk

doi: 10.1108/ILT-05-2013-0058pmid: N/A

Purpose – The purpose of this paper is to investigate the tribological behaviour of commercially available SAE 10 mineral and rapeseed oils containing Fe particles synthesized directly in the oil phase. Design/methodology/approach – Sub-micron Fe particles (50-340 nm) were synthesized by wet chemical reduction reaction of FeSO 4 by sodium borohydride in the rapeseed and mineral oils in the presence of surfactant: block copolymer (ENB 90R4) or oxyethylated alcohol (OS-20). A four-ball wear tribometer was used to investigate the tribological properties of mineral and rapeseed oil: coefficient of friction (COF), wear scar diameter and wear loss. Viscosity measurements of oil solutions and determination of synthesized Fe particles size were performed as well. Findings – The presence of Fe particles (0.1 weight per cent) in the rapeseed and mineral oils caused the little change in the COF but resulted in marked improvement of anti-wear property. The oils containing Fe particles with slightly higher viscosity are giving more friction due to viscous drag. The anti-wear enhancement is attributed to the formation of tribofilm and superior load-bearing capability of the modified oil. Both rapeseed and mineral oils irrespective of used surfactant in the presence of 0.1 weight per cent Fe particles (50-140 nm) show sufficiently improved anti-wear properties. Originality/value – The data collection about tribological behaviour of oils containing Fe particles and various additives in lubricants has a practical interest. The findings could be helpful to increase the knowledge of the behaviour of real tribological systems, where the metallic debris are generated during friction and contaminate the lubricating oil.

Buczek, Bronislaw ; Zajezierska, Anna

doi: 10.1108/ILT-07-2013-0082pmid: N/A

Purpose – The aim of this paper was to investigate the possibility of reusing frying oil, obtained during thermal treatment of food in fast-food restaurants for production of plastic greases. Design/methodology/approach – In accordance with the proposed research concept, the used frying oil was to be the base oil of biodegradable plastic greases thickened with calcium 12-hydroxystearate and lithium 12-hydroxystearate. These studies included the determination of the effect of variable amounts of used oil component in the base oil on the properties of the resultant plastic greases. Findings – It was found that the optimum amount of the component in the base oil is 10-15 per cent. Calcium and lithium greases prepared in such a way possess a quality to that of greases prepared with fresh rapeseed oil. Research limitations/implications – Higher concentrations of used frying oil in the base oil adversely affect the degree of thickening, thixotropic properties and dropping point of the grease, as well as, creating technological problems. Practical implications – The investigations, beside their research goals have also a practical character – recycling waste material in place of its present method of disposal. Originality/value – One of the least expensive material, and most commonly used to produce biodegradable lubricants are vegetable oils. In recent years, besides introducing biodegradable lubricating oils, increasing interest is observed in the use of plastic greases of high biodegradability. Now, it is possible to obtain such greases with additive of used frying oils. Biodegradable greases are used as lubrication of open gear, food production equipment, central lubrication system in cars and railway engineering.

Meng, Qingrui

doi: 10.1108/ILT-05-2013-0050pmid: N/A

Purpose – The purpose of this paper is to reveal the effect of starting time on hydro-viscous drive speed regulating start. Design/methodology/approach – The modified transient Reynolds equation, thermal energy equation and temperature–viscosity equation were solved simultaneously by using finite element method. And then variations of the oil film load capacity, variations of temperature and variations of the torque generated by the oil film during the starting process were obtained. Findings – The results show that during the starting process, both the oil film load capacity and the temperature show an upward trend, the torque increases during the beginning period and then decreases during the latter part of the starting process. When the starting time is less than 60 s, variations of the oil film load capacity and temperature show fluctuations, which decrease with the starting time. For any output speed, the corresponding oil film load capacity, temperature and torque decrease with the starting time, and the decreasing amplitude also decreases with the starting time. Originality/value – This paper indicates that the starting time can be set to 60-90 s to obtain a perfect starting process. The simulation results are verified by the speed regulating start experiments. Research findings of this work provide theoretical basis for the design and practical application of the hydro-viscous drive equipments.

Thakre, Avinash A. ; Thakur, Animesh

doi: 10.1108/ILT-06-2014-0057pmid: N/A

Purpose – The purpose of this paper is to include investigation on extreme pressure lubrication behaviour of Al 2 O 3 nanoparticles suspended in SAE20W40 lubricating oil. Effects of nanoparticles size (40-80 nm) and its concentration (0-1 per cent) on the coefficient of friction is studied using pin-on-disc tribotester. Design/methodology/approach – Taguchi technique is used to optimize the process parameters for lower coefficient of friction. L18 orthogonal array involving six levels for one factor and three levels for remaining three factors is selected for the experimentation. The parameters selected for the study are sliding speed, normal load, nanoparticles size and its concentration in base oil. Findings – It has been found that the presence of nanoparticles in proper concentration shows excellent tribological improvement in frictional characteristics compared to the base oil. The optimal combination of the parameters for minimum coefficient of friction is found to be 0.8 per cent concentration of 60 nm sized Al 2 O 3 nanoparticles, 1,200 rpm sliding speed and 160 N of normal load. The mechanism of friction reduction in presence of nanoparticles is investigated using scanning electron microscopy. Originality/value – This is the original work.

Cui, Gongjun ; Wei, Jin ; Wu, Gongxiong

doi: 10.1108/ILT-07-2014-0065pmid: N/A

Purpose – The purpose of this study is to prepare new Fe-Cr-B alloys which have better wear resistance and investigate the wear mechanisms of these alloys tribotesting against SiC ceramic balls under dry sliding process. Design/methodology/approach – Fe-Cr matrix alloys were fabricated using powder metallurgy route. The tribological behaviors of Fe-Cr alloys tribotesting against SiC ceramic balls using a ball-on-disc tribotester were studied at different testing conditions. Meanwhile, microstructure, phases and morphology of worn surfaces were investigated. Findings – The element boron improved mechanical properties and tribological behavior of alloys. The friction coefficients of Fe-Cr matrix alloys did not show obvious difference. The specific wear rates of alloys decreased and then increased because of the brittleness of alloys with the increase of boron content. Fe-21 weight per cent Cr-7 weight per cent B alloy showed the best tribological properties in dry sliding. The wear mechanism of Fe-Cr alloy was plastic deformation and abrasive wear. However, the Fe-Cr-B alloys showed fatigue spalling characteristics. Originality/value – This paper reported a new, cheap and wear-resistant Fe matrix material to prepare mechanical parts in food and mining industrial fields.

Ganiger, Basavaraj Mallappa ; Tumbigeri Mata, Chandrashekharaiah ; Manohara, H R ; Prasad, T B

doi: 10.1108/ILT-08-2014-0078pmid: N/A

Purpose – The main purpose of the research paper is to study the effect of refinement of primary silicon on sliding wear behavior of commercially available LM-28 alloy and correlate these with the micro-structural and mechanical properties. It is well known that the refinement of primary silicon increases the toughness, ultimate tensile stress (UTS) and wear resistance of the Al-Si alloys at ambient temperature. But exact addition level is not clearly mentioned in the paper; hence, the present paper throws light on the addition level for refinement of primary silicon present in LM-28 alloy. Design/methodology/approach – In the present paper, commercially available LM-28 alloy was prepared in the laboratory before and after the addition of Cu-P master alloy. Further wear studies will be carried out at room temperature. Wear properties are correlated with microstructure and mechanical properties. Findings – Improvements in mechanical properties were observed after refinement of the primary silicon present in LM-28 alloy. Research limitations/implications – Further studies are required regarding in-depth investigation of refinement of primary silicon and its effects on the life of the components prepared by this alloy. Practical implications – The data obtained from the research paper help the manufacturers of automotive, aerospace and marine components, such as pistons, cylinder heads and blocks, etc. Social implications – The present research work will be an essential information required for the students of undergraduate, postgraduate and research scholars to carry out research at an R&D centre. Originality/value – Experiments are conducted at an R&D centre and analyses were carried out for structural changes, mechanical properties and wear properties. Further, the results are compared with other researcher’s data.

Wang, Nan ; Meng, Qingfeng

doi: 10.1108/ILT-08-2014-0079pmid: N/A

Purpose – The purpose of this paper is to provide a nondestructive monitoring method based on wireless sensor technology to measure the continuous circumferential film pressure on radial cross-section of water-lubricated bearing, in addition, to study the influence factors to wireless communication. Design/methodology/approach – The unique shaft and wireless equipments are designed, the pressure sensors are installed in right shoulder of shaft, the wireless transmitter is installed at the end of shaft and the sensors are connected with wireless transmitter by data cable. By this way, the film pressure can be obtained via wireless communication. The film pressure of eight grooved water-lubricated rubber bearings with concave staves is measured, the performance evaluation of wireless equipments is conducted and the influence factors to wireless communication is analyzed by Doppler frequency shift theory. Findings – The rupturing and nonuniform water film is observed, the grooves decrease the film pressure of rubber bearing which is in mixed lubricating state. The main influence factor to wireless communication is shaft speed which has greater effect on packet loss rate than that on bit error rate. Practical implications – By studying the actual continuous water film pressure, the bearing properties can be studied in-depth, and this has significant meaning to the design and application of bearing. Moreover, the study on influence factors to wireless communication can be used for references to other wireless monitoring on rotating machinery. Originality/value – The continuous water film pressure can be monitored by this method, the lubricating state of bearing working surface cannot be damaged and the signal attenuation can be avoided. Therefore, the measuring accuracy is promoted and the measuring process also becomes convenient and high efficiency.