{"data":{"fields":"term_definition","term_definition":"
Gear teeth can be manufactured with a wide variety of shapes and profiles. The involute profile is the most commonly used system for gearing today. An involute is a curve that is traced by a point on a taut cord unwinding from a circle, which is called a base circle. The involute is a form of spiral, the curvature of which becomes straighter as it is drawn from a base circle and eventually would become a straight line if drawn far enough. An involute drawn from a larger base circle will be less curved (straighter) than one drawn from a smaller base circle. Similarly, the involute tooth profile of smaller gears is considerable curved, on larger gears is less curved (straighter), and is straight on a rack, which is essentially an infinitely large gear. Involute gear tooth forms and standard tooth proportions are specified in terms of a basic rack which has straight-sided teeth, for involute systems.<\/div>
\"ED-88a\"<\/div>
\"ED-88b\"<\/div>"}}