Patent ID: 8684879

Claim:
An eccentric oscillating gear device for transmitting driving force while changing a rotation speed at a given rotation speed ratio between a first member and a second member, comprising: a crankshaft having an eccentric portion; a gear member having a tooth portion and a through-hole in which the eccentric portion is inserted; a first cylindrical section adapted to be attachable to one of the first and second members; and a second cylindrical section adapted to be attachable to a remaining one of the first and second members, wherein: one of the first and second cylindrical sections rotatably supports the crankshaft; a remaining one of the first and second cylindrical sections has a tooth portion meshed with the tooth portion of the gear member; the first and second cylindrical sections are adapted to be rotatable concentrically and relatively with respect to each other according to an oscillating movement of the gear member along with a rotation of the crankshaft, and wherein the eccentric oscillating gear device is provided with a rotational phase adjusting section for setting an orientation of the crankshaft about an axis of the crankshaft on the basis of orientations of the first and second cylindrical sections about an axis of the first and second cylindrical sections so as to prevent the orientation of the crankshaft about the axis of the crankshaft with respect to circumferential directions of the first and second cylindrical sections from changing from an orientation of the crankshaft before disassembling way when the crankshaft is re-assembled in the eccentric oscillating gear device.