摘要 |
Novikov gearing obtains its exceptional tooth surface load capacity by using concave-convex circular arc profiles of nearly the same radii, so that the contact area between mating teeth is very large and the Hertzian stress low. Because the centers of these arcs are very close together, a small error in center-distance produces excessive changes in pressure angle and overloads the tips of the concave teeth. The subject invention eliminates this problem by using profile curves having a radius of curvature that increases with distance from the pitch circle. The discrete arc centers of Novikov gearing are replaced by continuous evolute curves which are positioned to be tangent to the pressure line near the point where it passes through the pitch point. This allows much closer profile conformity for a given center-distance error, reducing surface stresses and increasing torque capacity. |