円筒ころ軸受における部分円弧クラウニングと対数クラウニングの実験的比較

摘要

円筒面や円すい面が接触するとき，接触の端部ではrn応力集中が生じて接触面圧が過大となることが知られrnている．この端部の過大な接触状態をエッジロードとrn呼ぶ．通常，ころ軸受ではエッジロードを避けるため，rnころ転動面と軌道輪軌道面のいずれかあるいは両方にrnクラウニングが施されている．%A logarithmic profile is an essentially optimal geometry for rolling machine elements such as bearing rollers and raceways. Under most conditions of loading, it yields less stresses to give longer endurance. Lundberg first suggested the basic profile, and some researchers followed him by modifying it to suit engineering requirements. The authors also proposed a mathematical optimization method for various profiles including a logarithmic one in roller bearing applications. In this paper, rolling contact fatigue life tests are carried out to make a comparison of logarithmic, standard partially crowned and modified partially crowned rollers when they are applied to cylindrical roller bearings. Results show that the logarithmic and modified partially crowned rollers are comparable in fatigue life, and outlast the standard partially crowed rollers if they are fully lubricated. On the other hand, under poor lubrication, the logarithmic rollers are found to yield outstanding fatigue life over the modified partially crowned ones.