Sumitomo Heavy Industries, Ltd.

Yuji Maeguchi

Kiyoji Minegishi

Masayuki Tanigawa

Hideaki Harada

Keiji Takehara

An internal planetary gear device having an input shaft, an eccentric body rotating with the rotation of the input shaft, an external gear eccentrically rotatably mounted on the eccentric body through a bearing, an internal gear internally meshing with the external gear, and an output shaft connected to the external gear through a device for taking up only components of rotation of the external gear, wherein, each component is manufactured of resin, and one of the internal teeth of the internal gear and the external teeth of the external gear is formed into a tooth profile including an inner envelope configuration of curtate epitrochoid theoretical curve C, while the other, into a convex circular tooth profile.

Internal planetary gear device

A series of geared motors in which change gear ratios of 1/2-1/100 or a wider range of change gear ratios are realized in the single series based on the unified design concepts of low noise, high rigidity and high durability, and in which the separation, exchange, etc. of the individual speed change gears and motors proper of the geared motors are facilitated. In the series, a speed change mechanism in each of the geared motors constituting a group of 'high' change gear ratios comprises a single-stage type planetary gear mechanism of oscillating inner gearing system, a group of 'medium' change gear ratios comprises a single-stage type simple planetary gear mechanism, and a group of 'low' change gear ratios comprises a modified simple planetary gear mechanism including a sun gear (302 in FIG. 1), a first planet gear (304A), a second planet gear (304B) which rotates unitarily with the first planet gear (304A) and which has a larger number of teeth than the first planet gear (304A), and an internal gear (306). Herein, the principal gear ratio part of each of the speed change gears of the geared motors constituting the respective groups of change gear ratios is sealably supported at both the ends thereof.

Growing community of inventors

Ohbu, Japan

Yuji Maeguchi