Operational Condition and Superfinishing Effect on High-Speed Helical Gearing System Performance

An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system. Oil inlet temperature was varied from 160 to 250 F. Also, the test gears were run in both an as-ground condition and after isotropic superfinishing (ISF) condition. In-depth temperature measurements were made across the face width and at the axial end of the gear mesh. Supply power measurements were made at varying speeds and loads up to 5000 hp and 15000 rpm (pitch line velocity to 24000 feet per minute). Test results from the parametric studies and the superfinishing process are presented. The tests indicated that superfinishing offered no improvement in performance due to the high lubricant film thickness generated by the extremely high pitch line velocity that the majority of the tests were conducted. Increasing lubricant inlet temperature had the most dramatic effect on performance improvement.