COMPARISON OF TRIBOLOGICAL PROPERTIES OF HCR GEARS COATED BY PVD COATING TiAlN+DLC IN BIO-FRIENDLY AND CONVENTIONAL LUBRICATION ENVIRONMENTS

The submitted scientific experiment deals with the application of PVD (Physical Vapour Deposition) coating TiAlN+DLC in two different lubrication environments, also the article deals with the comparison of a lifetime of coating in mentioned lubricants. The PVD coating TiAlN+DLC was selected according to previous experiments carried out in the same field of laboratory works at Slovak University of Agriculture in Nitra. The coating was deposited on HCR (High Contact Ratio) gears with properties explained in chapter Materials and methods. HCR gears were selected according to the previous research performed on that type of gears. HCR gears were made from material 14 220 (16Mn[Cr.sub.5]). As lubrication environments were chosen ecological lubricant OMW Biogear S150 and conventional lubricant MADIT PP 90H. These two lubricants were selected according to the application in the previous research carried out in the workplace. Experimental tests were performed on the Niemann M01 FZG testing rig (back-to-back). That testing rig was used for the comprehensive measurement of the scuffing tests. In the experiment, we followed standard STN 65 6280, for FZG scuffing tests, from which we gained the load values for different load levels. After each load level were measured values of the maximum height of the measured profile Rz, by portable surface roughness tester Mitutoyo SJ-201, for the tip and the reference diameters on gear and pinion. Results of experimental tests were statistically processed and on a basis on them were established relations between the maximum height of the assessed profile and load level for both used lubricants as the dependence of change maximum height of the assessed profile Rz on the load level. Performed experiments showed that application of PVD coating TiAlN+DLC is possible in both used environments. Keywords: biological oil, HCR gears, PVD coating TiAlN+DLC, FZG test