Strengthening the Working Surfaces of Gears Through Dynamic Burnishing

Abstract Known solutions of devices for crush hardening do not ensure sufficient effectiveness of machining the teeth of a gear working surfaces. Due to the need to increase the load to working machines, and thus the degree of gear effort, while reducing their dimensions (i.e. downsizing), it is necessary to search for, test and implement new solutions for strengthening the gears. The proposed solution of the device, intended for jet burnishing the working surfaces of the gear teeth with an arch tooth line met the increased requirements regarding the effectiveness of strengthening. Effective cooling and lubrication of the processed surface and a significant increase in the dynamic burnishing force enable exceptionally favourable operational properties of gear wheels to be obtained using the discussed device. The opposite direction of the peripheral speed of the machined wheel in relation to the speed of the burnishing stream allows for obtaining the greater depth of surface deformation, generating higher compressive residual stresses in the surface layer. The parameters of the burnishing process with this device can be easily adjusted within wide limits, and the final effect depends on the selection of the diameter and type of the backshot material, its ejection speed, processing time and the number of processing passes.