Question

QUESTION 1 A portion of a shaft where gear is to be mounted has a diameter of 134 mm. The gear transmits 446 N.mm of torque. The shaft is to be made of SAE 1040 cold-drawn steel. The gear is made from SAE 8650 OQT 1000 steel. The key is made from SAE 1018 steel (Sy: 372 MPa; Su: 441 MPa) The width of the hub of the gear mounted at this location is 10 mm. Compute the Shearing force acting on the key (N)? QUESTION 2 A splined connection is used for the gear and the shaft assembly. A torque of 639,524 N.mm is transmitted by the splines. A normal pressure on the splines is equal 6 MPa. The dimensions of splines are: Major diameter = 97 mm Minor diameter = 43 mm Number of splines = 4 Compute the length of the hub of the gear (mm)?

Answer 1

- key matesial SAE 1018 steel → sy=372 MPa - sua 441 MPa . Yield strenth in shear CS sy) sy=0.5 Sy=0.5% 372 ssy=186 MPa - No factor of safety condition is given, hence, Talu = 186 MPa – Tau = P_ --- 0 be bi width of key li length of key -

- Shear force, gential to the of keys, P is assumed tan- shaft in analysis i P = Mt = 20 1/2 d Me= Transmitted torque da shaft diameter pa shear Force p=2x 4h6 - 134 s taa Shear Force = 6.657 N

. 92: From som Analysis of Splines, Mt=Pomil.n.%02d3) where maa Tran ssure b ma= Transmmited torque Pm = Permissible Pressure e = length of hub n = No. of splines Da Major Diameter de Minor Diameter substituting values, 639524 = 4x 6x IX 4697?–433) - Solving, 2 I length of Hub=28.198 mm