Limit Design of Internal Gears for Hypocycloid Reduction Gears Using Optimal Design System for Gears : Vibration, Control Engineering, and Engineering for Industry, New materials, new energy, biotechnology, electronics, etc.

Hypocycloid reduction gears produce a maximum reduction ratio, if the difference in the numbers of teeth between the internal gear and pinion is reduced to 1. However, such a limit design is very difficult, because such a reduction of the difference in the number of teeth induces various interferences. An internal gear having a zero difference in the number of teeth is best suited for a planetary gear mechanism that transmits its absolute rotation to the driven shaft at the ratio of 1 : 1. However, such a special gear set needs an operating pressure angle of 90 degrees, and thus cannot be designed by conventional formulae for ordinary internal gears. The author has so far devised an optimal designing system for the automatic design of internal gears. This paper presents an advanced application of the optimal design system to the automatic design of the above-mentioned special internal gears that require an extraordinarily difficult and special designing technique. Trial fabrication was also undertaken to confirm the designing computations obtained.