Spur gear profile with evolute shape - has two spherical contact surfaces one concave and other convex

摘要

The intention of the design is to reduce tooth interference thereby minimizing wear and loss of power. There is also an improved load capacity since a large proportion of the contact surface between the teeth is in fact in contact when throughout the period of load application. consequently a smaller gearwheel can be used with consequent reduction in weight and manufacturing cost. The spherical curvature of the teeth runs along the teeth and the radius of curvature on each face can be quite similar where there is a little play in the shaft and fine tolerances. Where there is play and the tolerances are larger a sharper curve is required on the convex surface than on the concave surface. The gear can be machined using normal machine tools.