Worn Gear Contact Analysis

摘要

How does one perform a contact analysis for worn gears? Response provided by Dr. Stefan Beermann: Wear is an ongoing process that decreases the quality of a gear with increasing number of load cycles. So typical issues addressed by a contact analysis of a worn gear is the transmission error caused by the deviations from the involute, and maybe the effect on the contact stress due to nicks and edges on the theoretically smooth profile. Also, the change in load distribution is of interest. The information about the wear can come from two sides: it might be from simulation or from a real gear measured on an appropriate measuring machine. In the first case there is usually no problem to get the worn profile into the contact analysis. In the second case you have to be careful in the preparation of the profile data; scan the gear on a measuring machine. Use a high resolution, preferably more than 100 points-per-flank. Then the best next step would be to read the points into a CAD package and convert the points into a curve. For instance - a spline curve or circular arcs. Here you have to pay extra attention, since you might analyze approximation artifacts afterwards instead of the effect of the wear.