AGMA 07FTM13 PDF

The demand for continuous improvement concerning economic efficiency of products and processes leads to an increasing cost pressure in manufacturing and design of power transmissions. Also, the power density of gears has been increased which leads to a demand for higher gear quality. In more and more cases this can only be achieved using hard finishing processes. The demand for higher gear qualities leads to an increased use of gear grinding, which incurs the risk of thermal damage, such as grinding burn on the gear flank. The influence of thermal damage on the set in operation is nevertheless hard to judge so that damaged gears are often scrapped. This leads to increasing failure costs. The lack of knowledge of the effect of grinding burn on the load carrying capacity of gears leads to the point that the same degree of damage is judged differently by different companies. Therefore it is necessary to do trials with thermally damaged parts in order to know how much a certain degree of thermal damage influences the load carrying capacity. The investigations described in this report are aimed at determining the load carrying capacity of parts under rolling stress. Thermally damaged rollers are employed on a roller test rig, since with this analogy process the part geometry is easier to describe and easier to damage reproducibly.