Increasing the flank load capacity by combination of shot peening and superfinishing

Author:  J. Kritzler
Source:  Conf Proc 2014: ICSP-12 Goslar, Germany (pgs.530-534)
Doc ID:  2014132
Year of Publication:  2014
Abstract:  
Hardfinishing by grinding of case hardened gears is a common process in the gear industry with a final roughness of the flank normally Ra= 0,3 - 0,5 μm. The German Gear Assosiation (FVA) set up a research program to test gears with overheated grinding zones. They tested flank conditions which were slightly tempered, strongly tempered and re-hardened [1].The shot peening process was tested as a repair tool for these damaged gears. After finishing this research program, it was set up a second program in 2009 with the focus to find out the increase of the flank load capacity by using three different surface treatments. Increasing demands on modern transmissions had led to the use of new technologies for the optimization of the flank load capacity [2]. These tested gears were "optimally processed", without any negative influence. All gears were tested on greystraining failure. This program compared mechanical vibrofinishing, chemically assisted vibrofinishing and shot peening followed by chemically assisted vibrofinishing. The paper will present the results of the different treatments, including shot peening, followed by the C.A.S.E. superfinishing process.