Tsubaki Power Lock Inch Series

Technical NotesSELECTION GUIDE AND PROCEDURETsubaki: The solution for shaft locking devicesSL SeriesSTEP 1(1) Material StrengthLarge contact pressure applies to both the shaft and hubduring installation. Select shaft and hub materials that meetthe following strength requirements.σ0.2S≧1.2×PShaft and HubP : Contact pressure on the shaftP´ : Contact pressure on the hubσ0.2S : Yield point of shaft materialσ0.2B : Yield point of hub materialσ0.2B≧1.2×Ṕ(2) Hub Material StrengthTorque and contact pressure will combine and producestress on the hub. Calculate this stress using one of thefollowing four formulas.(a) Stress applied to the hub from a normal direction (σw)σW=−PP: Shaft contact pressure(b) Stress applied to the hub from a tangential direction (σt)EL SeriesSTEP 1 Actual Locking Force,Transmissible Torque and Contact Pressure(1) When the required transmissible torque Mt isdifferent from the (Mt) listed in the EL SeriesSpecifications tableCalculate the actual locking force Fe, thrust Pax, contactpressure P and P' using the following formulas.C1 = Mt/〔Mt〕(Required transmissible torque ratio)Fe = C1×〔Fe〕(Actual locking force)F = Fo+Fe (Total Force)Pax = C1×〔Pax〕(Transmissible thrust)P = C1×〔P〕(Contact pressure on the shaft)P´ = C1×〔P´〕(Contact pressure on the hub)Mt: Required transmissible torqueFo, [Fe], [Mt], [Pax], [P´]: Values are listed in EL SeriesSpecifications tableP : Contact pressure on the shaftP´ : Contact pressure on the hubdW : Shaft diameterd : Hub outer diameter(c) Shearing stress applied to the hub by torsional force (τB)(d) Combined stress applied to the hub(σv)Make sureσ0.2B (yield point of the hub material) is greaterthanσV. σV