PSI - Issue 57

Dr.-Ing. D. Jbily et al. / Procedia Structural Integrity 57 (2024) 199–216 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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6336-22 is lower than that of the SP gear because it has a lower local specific lubricant film thickness. The safety factors of SP gear are higher than 2.

Area where micropitting was observed on tested REF and SP gears.

Fig. 19. Micropitting safety according to ISO 6336-22 The analytical results obtained show that micropitting is most critical in areas of high sliding velocity, high contact pressures and especially lower specific lubricant film thickness. Thus, the micropitting risk is increased in the area near the beginning of meshing. Approaching the pitch point C, micropitting changes into pitting. By comparing the analytical results presented above with the experimental results, the ISO results provide a good correlation with the occurrence of micropitting on the tooth flanks, an example of the occurrence of micropitting on test gears is shown in Fig. 20. REF Pinion SP Pinion

REF Gear wheel

SP Gear wheel

Fig. 20. Appearance of micropitting on test gears after 135 000 load cycles