>> P.223
LoadRatingandLifeLifeoflinearmotionrollingguidesDynamictorqueratingTEveninnormaloperationalstatus,alinearmotionrollingguidewillreachtheendofitslifeafteracertainperiodofoperations.Asrepeatedloadisconstantlyappliedontoaracewayandrollingelementsofthelinearmotionrollingguide,thisleadstoleprousdamage(scale-likewearfragments)calledfatigueflakingduetorollingcontactfatigueofmaterials,itwillbeunusableattravelingdistancebeforeoccurrenceofthisfatigueflakingonaracewayorrollingelementsiscalledthelifeoflinearmotionrollingguide.Asthelifeoflinearmotionrollingguidemayvarydependingonmaterialfatiguephenomenon,ratinglifebasedonstatisticcalculationisused.theend.TotalRatinglifeRatinglifeoflinearmotionrollingguidereferstothetotaltravelingdistance(1)90%ofagroupofthesamelinearmotionrollingguidecanoperatewithoutlinearmotionrollingguidematerialdamagesduetorollingcontactfatiguewhentheyareoperatedindividuallyunderthesameconditions.Note(1)StrokeRotaryBushingisrepresentedastotalnumberofrotations.BasicdynamicloadratingCDynamictorqueratingreferstoatorquewithacertaindirectionandsizewithwhich90%ofagroupofthesamelinearballsplinescanrun50x103mwithoutmaterialdamagesduetorollingcontactfatiguewhentheyareoperatedindividually.StatictorqueratingT0StaticmomentratingT0,TX,TYStatictorqueratingandstaticmomentratingrefertostatictorqueormomentloadgeneratingacertainlevelofcontactstressatthecenterofcontactpartsofrollingelementsandaracewayunderthemaximumloadwhenthetorqueormomentload(seeFig.1)areloaded,whichisthetorqueormomentloadattheallowablelimitfornormalrollingmotion.Generally,itisusedconsideringstaticsafetyfactor.LoaddirectionandloadratinginaccordancetotheLinearmotionrollingguideisusedwithitsloadratingcorrectedloaddirection.Basicdynamicloadratingandbasicstaticloadratingindicatedinthedimensiontableshouldbecorrectedbeforeuse.Asthevaluestobecorrectedvarydependingonseries,pleaseseeanexplanationforeachseries.loadratingreferstoBasicdynamicloadwithcertaindirectionandsizethatislogicallyendurableforratinglifeindicatedinTable1whenagroupofthesamelinearmotionrollingguidesindividuallyunderthesameconditions.isoperatedTable1RatinglifeSeriesCrossedRollerWayRollerWay&FlatRollerCageLinearSlideUnitLinearBallSplineLinearBushingStrokeRotaryBushingRatinglife100×103m50×103m106rotationsBasicstaticloadratingC0Basicstaticloadratingreferstostaticloadgeneratingacertaincontactstressatthecenterofcontactpartsoftherollingelementsandaracewayundermaximumload,whichistheloadattheallowablelimitfornormalrollingmotion.Generally,itisusedconsideringstaticsafetyfactor.AllowableloadFAllowableloadreferstoloadofsmoothrollingmotiononcontactsurfacetowhichmaximumcontactstressisappliedandthesumofwhoseelasticdeformationofrollingelementsandracewayissmall.Therefore,useappliedloadwithintheallowableloadrangeifverysmoothrollingmotionandhighaccuracyarerequired.Ⅲ-3
| < 
| 
> | 
>>
