Micro and Macroscopic Analysis of Fatigue Wear of Gear Wheel Top Layer – an Impact Analysis of Thermochemical Treatment

An analysis of form and size of the fatigue wear of gear wheel top layer of the prototype oil pump (type 3PW-BPF-24) is presented in the publication. The object of research was subject to endurance tests, so called labour resource test. During this test the pump was loaded in cycles with maximal working pressure. Additionally, continuous monitoring tests of exploitational and environmental parameters were conducted. After a completion of the endurance test the noticed superficial defects due to a phenomenon of the top layer fatigue and previously applied thermochemical treatment were measured and described. The work was finished with an analysis of obtained results and conclusions concerning a selection optimization of the thermal treatment parameters. Taking into consideration the presented results (suggestions) in the technology of improving strength prop-erties of gear wheels (of this type oil pumps) may render it possible to obtain an appropriate fa-tigue endurance of the top layer, i.e. a minimization of observed superficial defects.