Eccentrically oscillating gear device

An eccentrically oscillating gear device comprising:

• an internal gear having internal gear pins on an inner periphery thereof;
• a carrier rotatable relatively to the internal gear;
• a pair of bearings having a rolling element and a ring body for supporting the rolling element and disposed between an outer periphery of the carrier and the inner periphery of the internal gear;
• a crank shaft freely rotatably mounted on the carrier;
• and
• an external gear equipped with external teeth having a trochoid tooth profile on an outer periphery thereof in which tooth top portions of the external teeth are cut out, engaged with the internal gear pins on the outer periphery thereof, fitted to a crank portion of the crank shaft and disposed between the pair of bearings, wherein the external gear makes an eccentrically oscillating motion by rotation of the crank shaft so that a rotational output is taken out from the internal gear or the carrier, characterized in that receiving portions for receiving end portions of the internal gear pins are formed at end surface portions of an external-gear side of the pair of bearings, and the internal gear pins are supported by the receiving portions, thereby regulating movement of the internal gear pins to a carrier side.