Two-speed gearbox dynamic simulation predictions and test validation

David G. Lewicki, Hans DeSmidt, Edward Smith, Steven W. Bauman

Research output: Contribution to journalConference article

4 Scopus citations


Dynamic simulations and experimental validation tests were performed on a two-stage, two-speed gearbox as part of the drive system research activities of the NASA Fundamental Aeronautics Subsonics Rotary Wing Project. The gearbox was driven by two electromagnetic motors and had two electromagnetic, multi-disk clutches to control output speed. A dynamic model of the system was created which included a DC electric motor with proportional-integral-derivative (PID) speed control, a two-speed gearbox with dual electro-magnetically actuated clutches, and an eddy current dynamometer. A six degree-of-freedom model of the gearbox accounted for the system torsional dynamics and included gear, clutch, shaft, and load inertias as well as shaft flexibilities and a dry clutch stick-slip friction model. Experimental validation tests were performed on the gearbox in the NASA Glenn gear noise test facility. Gearbox output speed and torque as well as drive motor speed and current were compared to those from the analytical predictions. The experiments correlate very well with the predictions, thus validating the dynamic simulation methodologies.

Original languageEnglish (US)
Pages (from-to)487-499
Number of pages13
JournalAnnual Forum Proceedings - AHS International
StatePublished - Nov 15 2010
Event66th Forum of the American Helicopter Society: "Rising to New Heights in Vertical Lift Technology", AHS Forum 66 - Phoenix, AZ, United States
Duration: May 11 2010May 13 2010


All Science Journal Classification (ASJC) codes

  • Engineering(all)

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