Vibration Analysis of a Split Path Gearbox

Krantz, Timothy L.; Rashidi, Majid

Split path gearboxes can be attractive alternatives to the common planetary designs for rotorcraft, but because they have seen little use, they are relatively high risk designs. To help reduce the risk of fielding a rotorcraft with a split path gearbox, the vibration and dynamic characteristics of such a gearbox were studied. A mathematical model was developed by using the Lagrangian method, and it was applied to study the effect of three design variables on the natural frequencies and vibration energy of the gearbox. The first design variable, shaft angle, had little influence on the natural frequencies. The second variable, mesh phasing, had a strong effect on the levels of vibration energy, with phase angles of 0 deg and 180 deg producing low vibration levels. The third design variable, the stiffness of the shafts connecting the spur gears to the helical pinions, strongly influenced the natural frequencies of some of the vibration modes, including two of the dominant modes. We found that, to achieve the lowest level of vibration energy, the natural frequencies of these two dominant modes should be less than those of the main excitation sources.

Document ID

19950021434

Acquisition Source

Legacy CDMS

Document Type

Conference Paper

Authors

Date Acquired

September 6, 2013

Publication Date

May 1, 1995

Subject Category

Report/Patent Number

Meeting Information

Meeting: Joint Propulsion Conference

Location: San Diego, CA

Country: United States

Start Date: July 10, 1995

End Date: July 12, 1995

Accession Number

95N27855

Funding Number(s)

Distribution Limits

Public

Work of the US Gov. Public Use Permitted.

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