Search

Bearings can be classified as a rolling bearings and journal bearings. Bearings supports the shaft or axle loads usually have been occurred from gear, pulley, flywheel etc. In the bearing catalogues, the dynamic load rating (C) values given for each bearing are 90% reliable. When higher reliability is desired, the selection can be made using the relevant standards. During operation, bearing life and reliability are significantly reduced and premature damage occurs from improper lubrication, wrong bearing type selection, oil pollution, assembly damage, etc. In this study, considering the related ISO and DIN standards, the effects of factors on bearing life have been investigated such as reliability, oil contamination level, operating temperature, viscosity etc. [ABSTRACT FROM AUTHOR]

Copyright of Uluslararasi Ekonomi ve Yenilik Dergisi is the property of Karadeniz Technical University, Depertmant of Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the effects of ultrasonic vibrations on the lubrication between die and wire and wire drawing force in wire drawing process were investigated. In the work done, the lubrication effect and the drawing force in the wire drawing process are compared comparatively by using the conventional wire drawing method and the ultrasonic effect. Drawing force is measured with a dynamometer. In wire drawing process, evaluations were made by comparing macro images of wire surface in determining the effect of ultrasonic vibration on lubrication. The time-dependent force change graph obtained from the experimental studies was used to reveal the force differences between conventional wire drawing and ultrasonic vibrating wire drawing. At the end of the experiment, a sample with reduced diameter was taken and the surface quality of the sample was examined under a microscope. According to the results of the tests ultrasonic vibratory wire drawing showed a reduction of force between 9% and 15% in drawing force according to tradition. According to the studies made on the microscope, the lubrication ability of the wire surface was increased by the ultrasonic effect. For this reason, it has been found that the wire surfaces drawn by ultrasonic vibration are smoother. [ABSTRACT FROM AUTHOR]

Stainless steel materials have been used in many areas such as automotive, food, medical, chemical etc. by performing machining operations although having low thermal conductivity and work hardening tendency during machining. Cutting fluids have been applied in the machining of these materials. However, the cutting fluids have disadvantages such as harmful to the environment and health and the cost increment due to plenty of usage. Therefore, in this study, MWCNT (Multi-Walled Carbon Nanotube) reinforced commercial vegetable cutting fluid and WC (Tungsten Carbide) cutting tool were used in the milling of ferritic stainless steel by MQL (Minimum Quantity Lubrication) method. MWCNT particles were added to the cutting fluid at ratios of 0.1%wt., 0.15%wt. and 0.2%wt. to improve its cooling and lubricating properties. The effects of MWCNT particles, mixture ratios, and MQL flow rate on the cutting temperature occurred during milling operation were determined. The addition of MWCNT to the cutting fluid caused a decrement on the cutting temperature. However, an increment was observed when mixture ratio was further increased. Additionally, increasing of MQL flow rate reduced the cutting temperature. [ABSTRACT FROM AUTHOR]

Al/ SiCp composite materials produced by powder metallurgy and influences of lubricant addition zinc stearate, sintering agent magnesium and sintering environment nitrogen were empirically investigated on densification, microstructure, hardness and strength. Lubricant addition reduced green and sintered densities, therefore hardness and strength of the materials were affected detrimentally. Using nitrogen as sintering atmospher instead of air; density, hardness and strength were increased. High density values were obtained for 1 % magnesium content, decreased with increment of magnesium up to 3%, nevertheless hardness and strength values increased. [ABSTRACT FROM AUTHOR]

Considering today's competitive enviroment and the required emission regulations, it becomes increasingly important to reduce fuel consumption and harmful exhaust emissions in order to increase engine output power. This can be obtained by developing a well designed injection system or combustion chamber as well as by decreasing the mechanical losses, which are among the most important parameters affecting engine efficiency. The amount of wear rate and its location in the engine should be known to reduce mechanical losses. Therefore, piston ring-cylinder liner wear, which constitutes the greatest portion of mechanical losses, must be investigated. Researchers have attempted to measure the amount of wear by using various methods. In addition, there are also studies carried out to improve new coating materials or lubricants for reducing wear rate. In this study, these measurement methods are discussed and compared with each other in terms of their advantages and disadvantages. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Textiles & Engineers / Tekstil ve Mühendis is the property of Union of Chambers of Turkish Engineers & Architects, Chamber of Textile Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Teknoloji is the property of Engineering Science & Technology, an International Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)