Gear systems are among the most common mechanisms used for modern power transmission. There are a host of problems associated with their design. We have been particularly interested in the fact that the stiffness from the mating teeth is a function of time. This leads to parametric excitation of the system leading to some very interesting phenomena. Dynamic tooth loads are essential in determining the bending and contact fatigue lives of gear teeth.

Dynamic tooth loads result from the combined effect of inertia forces of gear wheels, the periodic variation of gear mesh stiffness, involute tooth profile errors and coupling with gear shaft lateral vibration. Gear failure can be generally classified into structural failures which include bending fatigue, tooth breakage and fatigue failure of gear webs, and lubrication failures which include surface pitting, scuffing and abrasive or corrosive wear. Structural failures are generally attributed to poor material, improper design or unexpected overloading arising from gear dynamics.

Here are links to some of our work.

• In-plane vibration of high-speed spur gear webs
• Parametric excitation effects in gear dynamics
• Stability and response of a spur gear pair
• Numerical simulation of nonlinear spur gear dynamics

This is a symposium on dynamics and vibration of geared systems that I co-organized for the ASME Vibrations conference.