>> P.37
Reliabilitycoefficientα1Reliabilitycoefficientscoverarangefrom90%to99.95%.Theyareshowninthetableatright.Reliability(%)Lnm90959697989999.299.499.699.899.999.9299.9499.95L10mL5mL4mL3mL2mL1mLLLLLLLL0.8m0.6m0.4m0.2m0.1m0.08m0.06m0.05mα110.640.550.470.370.250.220.190.160.120.0930.0870.0800.077LifemodificationcoefficientαisoThiscoefficientisderivedfromfatiguelimitload,contaminationcoefficient,viscosityratio,etc.Modernhigh-qualitybearingsteel,withgoodlubrication,cleanliness,andotheroperatingconditions,canachieveextremelylongratinglifeunderagivenload.Withthehigh-qualitybearingsgenerallyinuse,thecontactstressontherollingelementsandracewaysurfacereachesfatiguelimitstressat1500MPa,enablingtheratinglifetobeachieved.Thefollowinginfluencesareconsideredasfactors.•Bearingmodel,fatiguelimitloadandbearingequivalentload•Lubricationstatus(lubricanttype,viscosity,bearingspeed,bearingsize,etc.)•Operatingenvironment(pollutionclass,seal)•Contaminatingparticlesduringoperation(bearingsize,lubricationmethod,hardness,size,amount)•Mounting(contaminationcleanlinessduringassembly)Expressedbyαiso=fecCuP,κ.37