Computer Aided Design, Simulation and Transmission Error Analysis of a Face Gear Pair

Open Access
Froede, Erick W
Graduate Program:
Mechanical Engineering
Master of Science
Document Type:
Master Thesis
Date of Defense:
Committee Members:
  • Martin Wesley Trethewey, Thesis Advisor
  • Surendra B Rao, Thesis Advisor
  • Face Gear
  • Pericyclic Mechanical Transmission
  • Transmission Error
In recent years, there has been significant interest in the development of new and innovative rotorcraft gearboxes. Future helicopter transmissions aim to reduce overall gear train weight while maintaining efficiency and reliability. The Pericyclic Mechanical Transmission (PMT) is one of the compelling candidates that can achieve these goals. It consists of a high reduction ratio, high tooth contact ratio, and nutating/rotating mechanism which incorporates meshing conjugate face gear (FG) pairs. The use of a FG pair is novel for aerospace applications, and represents a new area of research. Accordingly, there is a distinct knowledge gap that must be bridged for this technology to become a reality. With the intention of supporting that effort, this investigation consisted of three key areas: 1) applying commercial modeling and simulation software; 2) conducting transmission error (TE) analysis, and; 3) exploring the performance of a FG pair. The first objective was achieved by generating the FG models with SolidWorks 2012-2013 and then introducing them to the commercial simulation package Abaqus 6.12-2 to evaluate static transmission error (TE). A novel three-dimensional expression of TE was specifically developed for use in a FG pair. When the simulation data was post processed it showed that the FG pair is capable of a peak-to-peak static TE of 0.382 μm. This result is significantly less than typical values found in industry, which bodes well for future applications. In addition, the physics of the system were well represented, with fluctuations in TE corresponding to teeth entering and leaving the FG mesh, stress concentrations on the inner tooth radius, and clearly visible contact lines (as a function of contact pressure) along a plane of contact. All of these behaviors were predicted by previous literature, and helped build confidence in the simulation. Lastly, the entire process was documented, providing a complete evaluation package for the future. These results represent original contributions to the understanding of a FG pair, which will be integral to developing the PMT as a viable next-generation solution for demanding aerospace applications.