spur gear selection for a required centre distance and gear ... be selected used and assessed by the following procedure select numbers of teeth in ... 2 sum gear teeth x pitch 1 /2 z1 z2 p from this initial selection each gear can be ... assessed for strength and wear using the following ... formulae the least of the four calculated powers is the capacity of ... multiplying actual power by a service factor relative to driver and driven equipment ... required capacity increase pitch or face width of gears adjust teeth sizes ... ,100 x 103 wear capacity pw xc x sc x yzxfxnxzxp1.8kw 10,000 x 103 where f ... face width mm n gear shaft speed r.p.m p ... gear pitch module no sb bending stress for gear material see below sc surface ...