Tooth Root Burnishing in the Kinematics of Gear Skiving

Gear skiving is known as a highly productive gear manufacturing process. Since small modulus gears require little installation space and generate low load-dependent gear power losses, they are particularly suitable for modern drive systems. As part of the demand for increasingly material-efficient gears, gears must transmit increasingly high loads. This requirement can be satisfied by mechanically imprinting compressive residual stresses which increase the tooth root strength. With a simultaneous smoothing of the surface, the micro-notch effect is reduced and the total fatigue strength is significantly increased. But the root fillet of small-modulus gears in modern drive systems limits the media size for shot peening, which has a negative impact on kinetic energy and therefore the depth effect. Additionally, it yields in increased roughness. Deep rolling, which performs remarkably well for simple geometries, involves the simultaneous smoothing of the surface and the introduction of residual stresses as a result of plastic deformation. Compared to shot peening, deep rolling does not rely on kinetic energy. Hence, a tool-concept of a novel tool system for mechanically strengthening the surface, as an adaption of deep rolling, in the tooth root in the kinematics of gear skiving is presented. ... mehrA simulation to calculate the contact trajectory and process parameters was developed for process and tool design. Subsequently, the tool system has been practically tested under variation of rotational tool speed and axial feed. The new process shows a high potential for the highly productive mechanical optimization of the tooth root surface properties.