Meshing analysis in case of noncircular gears designed for the nails forming kinematics optimization

Résumé

Industrial applications often require a variable output motion of mechanisms; noncircular gears are, nowadays, a competitive alternative to electrical devices as providers of variable motion. The authors propose noncircular gear pairs that would modify the kinematics of the crank-slider mechanism of a nail machine, in order to improve the quality of the products. In the attempt of optimizing the nail forming process, two variable slider motions and gear transmission ratios, respectively, are defined. Variation of the gear transmission ratio leads to variation of the noncircular gear geometry, with consequences on gear performances. The paper presents a study of the static tooth contact pattern of the noncircular gears, as
a qualitative criterion of the gears meshing, analyzing the influence the modifications in mechanism’s kinematics and gears geometry, respectively, have on the gear tooth contact. AutoCAD facilities are used to simulate the gears meshing and to illustrate the tooth contact pattern in static conditions, as a first step in the noncircular gears performances analysis.