A gearbox shaft that transmits 15 HP at 454 RPM has a gear medium radius bevel R1 = 8 cm and a straight tooth gear with primitive radius R2 = 3 cm. Both gears are mounted on the shaft by pressing adjustments. The tree is rectified and the Steel with which it is constructed has a tensile strength of 9000 kgf / cm2 and a limit of creep of 6850 kgf / cm2 . Knowing the geometry of the tree and the forces acting on it, Check if you will have infinite life. If not, determine life in hours. Ft 1 = 300 kgf, Fa 1 = 104 kgf, Fr 1 = 25 kgf, Ft 2  = 800 kgf and Fr 2 = 325 kgf.

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