Optimization of the application behaviour of spur gears by machine-hammered tooth surfaces (OptiGear)

Key Info

Basic Information

01.01.2018 to 31.12.2019
Organizational Unit:
Chair of Machine Tools, Gear Technology
German Research Foundation DFG



Dieter Mevissen

Oberingenieur GT


+49 241 80 27560



Starting Situation

Machine hammer peening is an industrial process for the surface treatment of highly stressed components. Machine surface hammering is used to smooth the surface, index residual compressive stresses and perform work hardening in the edge zone. In addition, MHP structures improve the tribological properties of the surfaces. Mechanical surface hammering has been incompletely researched as a method for optimizing friction and wear of the rolling contact of highly loaded gears.

Research Objective

The aim of the project is to optimise the application behaviour of cylindrical gears in the form of surface structures by mechanical hammering. The cause-effect relationships between the process kinematics of hammering and the resulting surface structures as well as the effects of these surface structures on the elasto-hydrodynamic lubrication condition and the wear resistance of rolling contacts are not known. Concrete basic research in this field is required to identify, quantify and explain the tribological mechanisms of action of structured surfaces in highly stressed rolling contact. On this basis, the interactions of the hammered surface structures with regard to tooth flank load carrying capacity, friction and wear must be investigated, understood and explained experimentally and numerically. Since mechanical surface hammering is an elasto-plastic pressure forming process, the interaction between the work hardening of the material and the tooth root fracture bearing capacity as well as the plastically modified tooth profile must then be investigated.