Ertugrul Durak and Hakan Ali Yurtseven
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…
Abstract
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.
Details
Keywords
Yasar Sevik and Ertugrul Durak
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…
Abstract
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.
Details
Keywords
Mustafa Kadıoğlu and Ertuğrul Durak
The purpose of this study was to examine the effect of the magnetic field to the friction coefficient in the rolling element bearings which exists in electric motors.
Abstract
Purpose
The purpose of this study was to examine the effect of the magnetic field to the friction coefficient in the rolling element bearings which exists in electric motors.
Design/methodology/approach
To achieve this, the test rig was modified to adjust the density of the magnetic flux applied to the rolling ball element bearing. Experiments were carried out in the magnetic field from 0 to 7.5 mTesla at magnetic flux density range from 15, 40 and 65 N constant loads. Also, its rotary speed selected as 100, 200, 400, 800 to 1200 rpm, respectively.
Findings
In the majority of the experiments, it was observed that the magnetic field affected the friction coefficient. This influence reduced the friction coefficient in some experimental conditions and increased in some of them.
Originality/value
In the literature, there are very few studies on the effect of magnetic flux density to the friction coefficient in these rolling element bearings. It has become clear that more studies have been conducted on the effects of the magnetic field and/or electrical current on bearing damages and failures. This aspect is a study with specificity.
Details
Keywords
Ertuğrul Durak, Özlem Salman and Cahit Kurbanoğlu
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…
Abstract
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 simulation results suggest that the artificial neural predictor would be used as a predictor for possible experimental applications, especially different lubrication conditions on the modelling journal bearing system.
Originality/value
The paper discusses a new modelling scheme known as ANNs. A neural network predictor has been employed to analyze the effects of a lubricant with a PTFE‐based additive on the friction behaviour in a steadily loaded journal bearing under different operating conditions.
Details
Keywords
Ertuğrul Durak, Hakan Adatepe and Aydin Biyiklioğlu
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…
Abstract
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 bearing's 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 one of the roles of an additive is to form a protective layer to reduce friction coefficient in lubricated contacts.
Originality/value
The paper is of value in presenting 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.
Ertuğrul Durak, Cahit Kurbanoğlu and Recai Fatih Tunay
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…
Abstract
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 öne of the roles of additives is to form protective layer to reduce friction coeffıcient 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 coeffıcient of friction were graphically presented. The highest reduction in the friction coeffıcient 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 coefficîent in the journal bearing under statically loaded have been studied experimentally at 25 and 100°C temperatures.
Practical implications
Lubricating oils find applications in engines, industrial uses, greases and automotive transmissions. The majör uses of these oils are in engines (55 per cent), industry (27 per cent), processes (9 per cent), greases (5 per cent) and automotive transmissions (4 per cent). Lubricants perform a variety of functions in automotive application. One of the important functions is to reduce friction and wear in movîng machinery.
Originality/value
Generally, by adding additives to engine oil the lower friction coeffıcient were observed comparison engine oil both at 25 and 100°C temperatures. But, the smallest friction coefficient was obtained in the tests at 100°C comparison with the tests at 25°C in the additive addition to engine oil tests.
Details
Keywords
Filiz Karaosmanoğlu, Serkan Yüzer, Hüsnü Kerpiççi and Ertuğrul Durak
– Refrigerant fraction and mixture viscosity values were determined for various operating conditions of compressors. The paper aims to discuss these issues.
Abstract
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.
Details
Keywords
Hakan Kaleli and Ertugrul Durak
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…
Abstract
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.