Contact Point Trajectories Research Articles

Worn tooth profiles and their influence on crossed plastic helical gears. 2nd Report, Three-dimensional representation of tooth profiles for small worn depth.

In order to study the wearing manner of the plastic helical gear composed of a crossed helical gear and a steel pair, the somewhat worn tooth profile is investigated theoretically on the assumption that the steel gear is not worn at all and that the shaft angle is 90° The trajectory of contact point is given numerically on the plastic tooth flank when it is not worn, and pairs of boundary curves are also given for several small worn depths defined on the pitch circle in the plane in which the common perpendicular is contained. The profile inside such a pair is the envelope of steel tooth flank moving relatively to the fixed plastic gear for named worn depth, but the outside is the original plastic tooth flank. The worn profiles are considerably different according to different helix angles, and they are represented three-dimensionally.