Problem $4$

Design a helical gear pair to transmit $18\mathrm{.}5kW$ at $1470rpm$ with a speed reduction ratio of $2\mathrm{.}5.$

Available is $a_1$ grade $2$ through hardened steel with quality number of $6$ and a Brinell hardness

number of $200.$ Apply a factor of safety of $3$ to the bending stress and $1\mathrm{.}5$ for contact stress. The

center to center distance of the shafts should not exceed $150mm.$