* Welcome to My Gear Design Topics *

Hi, my name is Chang H. Park. I am a gear engineer and computer programmer. I am developing this web site to introduce my advanced gear design technology and topics. You can contact me by clicking E-mail: backlash58@yahoo.com.

The above animation picture presents the tooth contact simulation of a gear set in which a pinion, painted in blue, and a gear, painted in green, are rotating in mesh. The pink curves indicate tip and root circles, and  white and red curves stand for involute tooth profiles and root fillets, respectively. In this graphic simulation of the tooth contact operation, you can see the backlash and clearances between the pinion and gear teeth. In addition, the most important thing in this animation picture may be the possibility of detecting tip-to-root interferences.  The interference, which should not be allowed, is defined as the contact between the root fillet of a concave body and the mating gear's tooth tip of a convex body or vice versa.

In general, the interferences are recognized to be worse than undercutting which is sometimes even allowed to avoid them. The numerical procedure for them is also more complicated than that for the undercutting. The graphic simulation, however, as shown above may facilitate the design task for the interferences. The one of alternative graphic simulation methods to detect the interferences may be possible by simulating the relative motion of the mating gear's teeth, which will be very similar to the tooth cutting simulation of shaper cutters. It seems like that, for the design task for the interference detection, the visualized graphic simulation is better than the numerical data produced by the difference in the limit diameter and the fillet diameter to the point of tangency between the involute profile and the root fillet.

Well.., I would like to say that, first of all, we had better program the computer graphic simulations for the interference detections and know the difference between the addendum modification coefficient and the generating rack shift coefficient, and nonstandard tooth thicknesses of cutting tools to follow the actual gear tooth generation by hobbing or shaping processes. Let me talk about them later.