>> P.26
T=9550000 ……………………………(14)HnKt= ……………………………………(15)TRKs=Kttanθ ………………………………(16)Kc= Kt+Ks=Kt22secθ…………………(17) where, T:Torqueappliedtogear,N-mm Kt:Tangentialforceactingongear,N Ks:Radialforceactingongear,N Kc:Resultantnormalforceongeartoothsurface,N H:Transmittingpower,kW n:Rotationalspeed,min-1 R:Pitchcircleradiusofdrivegear,mm θ:Pressureangleofgear,deg.KtKsRFig.6toothInthiscase,theresultantnormalforceonthesurfaceactsastheradialforcetotheshaftandthemagnitudeofvibrationorshocksvariesdependingontheaccuracyandsurfacefinishofthegear.Therefore,theradialloadKrappliedtotheshaftisobtainedfromthefollowingequation,multiplyingtheresultantnormalforceKcongeartoothsurfacebythegearfactorfzshowninTable8.Whenpoweristransmittedbyabeltorchain,theloadactingonthepulleyorsprocketwheelisobtainedfromthefollowingequations:T=9550000 ……………………………(11)HnKt= ……………………………………(12)TRwhere,T:Torqueactingonpulleyorsprocketwheel,N-mmBearingloadsincaseofbeltorchaintransmission Kt:Effectivetransmittingforceofbeltorchain,N H:Transmittingpower,kW:Rotationalspeed,min-1 n R: Effectiveradiusofpulleyorsprocketwheel,mmForbelttransmission,theloadKractingonthepulleyshaftisobtainedfromthefollowingequation,multiply-ingtheeffectivetransmittingforceKtbythebeltfactorfbshowninTable7.Kr=fbKt ………………………………………(13)Table7BeltfactorTypeofbeltV-beltsTimingbeltsPlainbelts(withtensionpulley)Plainbeltsfb2〜2.5.3〜212.5〜34〜5Inthecaseofchaintransmission,avalueof1.2to1.5istakenasthechainfactorcorrespondingtofb.Thethesprocketwheelshaftisobtainedloadactingonfromequation(13)inthesamemannerasthebelttransmission.BearingloadsincaseofgeartransmissionKr=fzKc……………………………………(18)toWhenpoweristransmittedbygears,theforceactingthetypeofgear.onthegearsvariesaccordingSpurgearsproduceradialloadsonly,buthelicalgears,bevelgearsandwormgearsproduceaxialloadsinadditiontoradialloads.Takingthesimplestcaseofspurgearsasanexample,thebearingloadisobtainedfromthefollowingequations:Table8GearfactorTypeofgearPrecisiongears(Pitcherrorandformerror:Lessthan0.02mm)Ordinarymachinedgears(Pitcherrorandformerror:0.02〜0.1mm)fz.05〜1.111.1〜1.3A23
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