A new noncircular gear pair to reduce shaft accelerations : A comparison with sinusoidal and elliptical gears

This article presents a new noncircular gear pair to obtain small shaft accelerations. The centrode contours may be controlled depending on the required maximum acceleration and smoothness of the centrodes. A comparison among elliptical, sinusoidal, and the new gears is provided. Results show that, for two-lobule gears, the maximum and minimum polar radii and gear ratios are the same for the new and sinusoidal profiles but differ for the elliptical ones. Conversely, there are significant differences in the maximum angular acceleration, tangential acceleration, and pressure angle. It is concluded that the novel gears provide not only small shaft accelerations, but also small tangential accelerations and pressure angles, and it is excepted that the elliptical gears may exhibit lower tangential accelerations and pressure angles for large values of the angular speed alternating component. Consequently, shaft and tooth loads and stresses may be lower for the new gears. This may result in more compact systems.