A $4-$cylinder internal combustion engine running at $1200$ rpm has its speed reduced by

approximately $1\mathrm{.}5$:$1$ in a V$-$belt drive to drive a $40$ kW blower. The blower runs for less

than $10$ hours per day. It is desirable that the belt speed is about and not exceeding $14\frac{m}{s},$

and the blower speed is within $780+-5\%rpm.$

Specify a standard V$-$belt cross section and determine the number of belts used in the belt

drive. You may use a correction factor of $0\mathrm{.}98$ for the angle of wrap and a correction

factor of $0\mathrm{.}94$ for belt length.

Ans: SPA, $6$ belts.