The aim of the research project was to expand the state of knowledge on the tooth flank and tooth root load-carrying capacity of case-hardened gears, which are intensively shot-peened after heat treatment and then subjected to a combined grinding and polishing process. This new type of process chain allows economical gear production of high load-bearing gears. Special shot peening processes, based on the findings of the FVA 812 project series, make it possible to introduce pronounced compressive residual stresses in depth ranges that are higher than the grinding abrasion. Since shot peening is carried out directly after heat treatment and the finishing process is carried out in combination with the grinding process to produce very smooth surfaces, no additional work steps are necessary compared to conventionally ground gears according to the state of the art.

In the predecessor research project FVA 521 III, spot tests for such manufactured gearings showed a very high pitting load-carrying capacity. Building on this test basis, further gear running tests were carried out in the current research project to determine the load-carrying capacity on a shot-peened and subsequently ground and polished variant. It was shown that pronounced compressive residual stresses remain in the tooth flank after the grinding process and that the test gears have very fine surface qualities. The test gears showed an extremely high pitting load-carrying capacity and fit into the already existing knowledge base from FVA 521 III. Pulsator tests were also carried out to determine the tooth root load-carrying capacity for the overall evaluation of the applied production chain.

The goal of the research project was achieved. The research project was able to show that very high pitting load-carrying capacities can be achieved through intensive shot peening followed by grinding and polishing.