Ertuğrul Durak

Using of Cottonseed Oil as An Environmentally Accepted Lubricant Additive

At the present time, to minimize friction and to control wear in machines elements are used with lubricating oil manufactured by advanced technologies. The high performance of lubricating oils is provided by oil additives. Additives improve the lubricating ability of the base oils by either enhancing the desirable properties, which is already present, or obtaining new properties. The decreasing of the worlds finite resources of mineral oil and the increasing environmental awareness have increased investigations about new environmental lubricant and additive candidates. Cottonseed oil (CSO) with Turkish origin was studied as an additive candidate in the presented study. Investigation of the effect of CSO addition to base oil on the friction coefficient was aimed in the journal bearing under static loading at ambient room temperature (25°C). Tests was performed by using base oil (SAE 20W50) alone and lubricating oil at concentration ratios 2.5, 5, and 10 vl % additives as CSO at five different speeds and three different loads. The experimental study clearly showed that the CSO could be used as an additive of friction modifier.

Measurement of friction force and effects of oil fortifier in engine journal bearings under dynamic loading conditions

Commercial base oil and oil fortifier added to this oil are used to investigate the frictional behavior of the engine journal bearings using the theoretical Reynolds equation and experimental test rig. In the theoretical part of the study, the Reynolds equation that states the pressure distribution and friction force with finite width was solved by using the finite difference method. In the experimental part of the study, a new design test rig was conducted to measure the friction force, the lubricant film thickness of the engine journal bearing using base oil under dynamical loaded conditions. The effect of oil fortifier was detected measuring the friction force every three minutes in each 360 crank angle during 15 minutes of experiment. As the theoretical friction results showed similar variation with the experimental measurements of engine bearings, adding oil fortifier to the base oil presented a substantial reduction of friction force during the testing period.

Analysis of effects of oil additive into friction coefficient variations on journal bearing using artificial neural network

Purpose – The purpose of this paper is to investigate the effect of a lubricant with a polytetrafluoroethylene (PTFE)‐based additive on the friction behaviour in a steadily loaded journal bearing using an experimental and artificial neural network approach.Design/methodology/approach – The collected experimental data, such as pressure variations, are employed as training and testing data for artificial neural networks (ANNs). A feed forward back propagation algorithm is used to update the weight of the network during the training.Findings – An artificial neural network predictor has superior performance for modelling journal bearing systems under different lubricant conditions.Research limitations/implications – A feed forward back propagation algorithm is used as a training algorithm for the proposed neural networks. Various training algorithms can be used to train the proposed network. Various lubricants and concentration ratio of the different additives can be investigated.Practical implications – The ...

Experimental investigation of porous bearings under different lubricant and lubricating conditions

The performance of porous bearing under different lubricants and lubricating conditions was experimentally investigated in this study. In order to carry out the experiments, a new test rig was designed to determine the tribological properties of based sintered bronze journal bearings that were manufactured by powder metallurgy (P/M) techniques. To determine the effects of lubricating conditions with and without oil supplement (OS) on the tribological characteristics of these bearings under static loading and periodic loadings, some experiments were carried out using different lubricants. In the tests, pure base oil (SAE 20W50), two fully formulated commercial engine oils (SAE20W50) and lubricating oils with commercial additive concentration ratio of3% were used. The worn surfaces of test bearings were examined using optical microscopy. Experimental results showed that the change in friction coefficient was more stable and in smaller magnitude under static loading than that of periodic loading. In addition, the friction coefficient and the wear rate conducted with base oil resulted in higher values than those of fully formulated oils with and without OS lubricating conditions. The experimental results obtained in this study indicated that the correct selection of lubricant and suitable running conditions were very important on the tribological characteristics of porous bearings.

Experimental study of the effect of additive on the tribological properties journal bearing under running‐in and start‐up or shut‐down stages

Purpose – The purpose of this paper is to study the effects of additive on the tribological properties such as friction coefficient and wear loss in the journal bearings during start‐up (or shut‐down) and running‐in periods.Design/methodology/approach – In this study, fully formulated commercial engine mineral oil (SAE 20W50) and commercial oil additives (3 per cent) added into this oil were tested to determine the tribological performances such as friction coefficient, wear loss and the effect of the additive on protective layers formed on the sliding bearings surfaces.Findings – This study presents an experimental procedure for obtaining practical results pertaining to the tribological performance of the journal bearing under running‐in and start‐up or shut down stages. Also, in this study, the authors have attempted to show the linkage between the oil additive and the running conditions such as running‐in and start‐up and shut‐down in effecting performance of the journal bearing. It is well known that...

Effects of boron oil fortifier on friction and pressure distribution in engine journal bearings

Additives are incorporated in engine oils to improve existing desirable properties of base stocks and to impart new specific properties required by modern engines. The additives include antioxidants, detergents, dispersants, corrosion and rust inhibitors, viscosity index improvers, pour point depressants, foam inhibitors and tribological agents. In this study, the effect of boron oil fortifier added into the base oil on friction coefficient and pressure distribution was investigated between sliding surfaces of engine journal bearings. Experiments were performed firstly using only base oil at different speeds and loads. Then, this test was repeated with different concentration ratio of 1, 3, 5 and 10 percent commercial boron additive.

Experimental study of effects of oil additives into coefficient of friction in journal bearings at different temperatures

Purpose – In this study, an attempt is made to show the linkage between the oil additive and journal bearing the running conditions such as temperature, load, speed, etc. in effecting lubricating. It is well known that one of the roles of additives is to form protective layer to reduce friction coefficient in lubricated contacts.Design/methodology/approach – The tests were performed at three different loads, and eight speeds. The tests were carried out for three different commercial additives that are concentration ratio of 3 per cent.Findings – The test results of the experimental coefficient of friction were graphically presented. The highest reduction in the friction coefficient was obtained at high temperature (100°C) in the tests than room temperature (25°C) tests.Research limitations/implications – In this study, effects of commercial oil additives on the friction coefficient in the journal bearing under statically loaded have been studied experimentally at 25 and 100°C temperatures.Practical implic...

Experimental study of the tribological properties of an elevator’s brake linings

Purpose This paper aims to design and manufacture a wear-test rig performing reciprocating movement that is more relevant to the elevator brake system. Also, a sample test result that was conducted in this experimental set-up is presented to evaluate the tribological properties of the brake linings of the elevator system that are activated in emergencies. Design/methodology/approach The brake linings are some of the most important security elements in elevators. The friction and wear properties of these brake linings have great importance for both safety and comfort. Elevator brake linings are often used in conjunction with guided rails under dry and boundary lubrication conditions. Therefore, friction coefficient and wear types occurring in the brake linings may be different. The tribological properties of the brake lining material in the literature are generally identified using a pin-on-disc wear-tester. The pin is contacted by rotating a disc in this wear-test rig. However, as the brake linings and guide rails do not have a reciprocating movement (linear translational motion) on each other, this wear-test rig is not suitable for brake linings and guide rails in the elevator system. Findings A sample test result that was conducted in this experimental set-up is presented to evaluate the tribological properties of the brake linings of the elevator system that are activated in emergencies. In these experiments, three different brake lining materials that are widely used in the elevator car guide rails in Turkey were tested under different speeds and loads. Originality/value The paper provides information about how to evaluate the tribological properties of the brake linings of the elevator system that are activated in emergencies. Also, it offers practical help for the manufacturer and researcher in the elevator sector.

The investigation of relationship between lubricating oil and refrigerant in refrigerator compressors

Purpose – Refrigerant fraction and mixture viscosity values were determined for various operating conditions of compressors. The paper aims to discuss these issues. Design/methodology/approach – In this study, an experimental setup that can be used to obtain refrigerant mass fraction and mixture viscosity data is designed and constructed. With the experimental setup, R600a mineral and R134a polyolester compressor lubricant mixtures were examined. Findings – This study presents an experimental procedure for obtaining practical results related to refrigerants used in the refrigeration system. Some properties of refrigerant-lubricant mixtures are very important for the design of compressors and performance of the refrigeration cycle. Originality/value – The paper is of value in presenting an experimental procedure for obtaining practical results pertaining to the tribological and other properties performance of the refrigerants.

Investigation of fretting wear in journal bearings

Purpose Fretting wear takes place when two contacting solid surfaces are subjected to relatively small amplitude oscillatory motion in the order of a few microns. The purpose of this paper is the design and manufacture of a fretting wear test rig that can analyze fretting wear on journal bearings. Design/methodology/approach This study included the manufacturing and operating principles of the test rig. In the test rig, the shaft was fixed and vibrational motion was given to the bearing housing. Vibration motion the amplitude of which could be adjusted was used on the test rig. The vibration motion was applied to a two-piece journal bearing on a fixed shaft supported from both ends. Findings Vibration amplitude was provided by a micro vibration engine (motor) to be under 100 μm. Originality/value Also, scanning electron microscopy, energy dispersive X-ray and X-ray diffraction analyses of the samples were investigated.