Production of a test mechanism for gear surface fatigue and investigation on the effect of the oil viscosity

ABSTRACTM. Sc. ThesisPRODUCTION OF A TEST MECHANISM FOR GEAR SURFACE FATIGUEAND INVESTIGATION ON THE EFFECT OF THE OIL VISCOSITYKerim KIZILASLANAfyonkarahisar Kocatepe UniversityGraduate School of Natural and Applied SciencesDepartment of Machine EducationSupervisor: Asist. Prof. Dr. İbrahim MUTLUGears are the ones which come first elements of movement and power transfer inmachinery systems. Gears are worn by time and then this comes with many negativefactors. After investigations it has been put forward that it depends on many factors tobe worn at gears. One of the most important of them is lubricator viscosity. It can besaid that pitting damages which is one of the wearing kind, are resulted frominsufficient lubrication conditions.In this experimental study case, the effects of different lubricants, which have severalviscosities, on spur gears which are used in power and motion transmission, have beeninvestigated. Experiments have been made on the gear fatiguing system which has beendeveloped by supports from the Fund of Scientific Investigations at University ofAfyon Kocatepe. In the system, load conditions were realized by electrical way unlikethe other systems which use mechanical way. Tests were done on special made spurgears. In order to investigate of the effects of several oil viscosities on gears, material,revolution count, temperature and load applied, were kept constant; on the other hand,variable lubricants which have several viscosities were used. Either before or after thetests, weight detection of the gear samples and measurement of the surface roughnesswere done.Thus, experimental samples have been stopped and investigated after 5 millionrevolutions. In according to the surface roughness tests the more oil viscosity decreasessurface roughness and material lose raise.vIt has been sought in the SEM photos that pittings get condensed on the edges of thegears. Also it is seen that they are in an irregular structure and also the more oilviscosity get lower pitting sizes get increase.Consequently, the answers have been sought for the questions like load carryingcapability of the oils which have several viscosities, and what kind of damages couldbe happened on the gear surfaces by those effects.2007, Page: 96Keywords: Spur gear, oil viscosity, wearingvi