This dissertation aims at developing a new gear mesh characteristic model for hypoid gears and applying the new theory to analyze right-angle geared rotor dynamics. First, the mesh characteristics of hypoid gear sets are investigated analytically. A new multi-point coupling gear mesh model based on a 3-dimensional tooth contact analysis is proposed. The new gear mesh model is formulated to represent the time-varying mesh properties of the hypoid gear pair under any load condition. Comparison of the new mesh model with geometry-based mesh models for a no load case is made and good agreement is obtained. A direct connection between the results of the gear quasi-static tooth contact analysis and gear dynamics is made possible with this new mesh model. This connection, which has not been derived prior to this dissertation, can be applied to gain quicker and clearer understanding of the gear mesh properties and possible influences on system dynamics.; Various dynamic models for a generic hypoid geared rotor system are studied next. Specifically, a 14-DOF non-linear dynamic model with multi-point coupling gear mesh model has been proposed and simulated successfully. Using this generalized model, the dynamic responses of four different cases are analyzed, namely, the linear time-invariant, linear time-varying, non-linear time-invariant, and non-linear time-varying formulations. Modal properties of the linear time-invariant model are studied in detail and the critical out-of-phase gear pair torsion modes are described. For the other three models that possess non-linear or time-varying effect, the numerical simulation method is applied to obtain the steady-state dynamic response spectrum. Effects of backlash, load, time-varying mesh, and their interaction are further studied. The computed response characteristics are also classified with time history and phase plots, which help to understand the severe non-linear behavior of the gear pairs under light load. Selected parametric and sensitivity studies are conducted to investigate the effects of misalignments and critical design parameters on system dynamics. Finally, a user-friendly hypoid gear mesh and rotor dynamics code is developed based on this dissertation research.
展开▼
