ECCENTRIC OSCILLATING GEAR ASSEMBLY

PROBLEM TO BE SOLVED: To suppress pitching on the tooth surface of an external gear caused by a stress received from an end portion of an inner tooth pin in the event of a temperature rise within an eccentric oscillating gear assembly. SOLUTION: The eccentric oscillating gear assembly includes: an outer cylinder 2 having a plurality of internal tooth pins 3 on the inner surface; a crankshaft 10 provided rotatably within the outer cylinder 2 and having eccentric portions 10a and 10b; external gears 14 and 16 attached to the eccentric portions 10a and 10b of the crankshaft 10 respectively and rotated with oscillation in cooperation with the eccentric rotation of the eccentric portions 10a and 10b while being engaged with the internal tooth pins 3; and a carrier 4 provided to be concentric to the outer cylinder 2 and rotating relatively to the outer cylinder 2 by transmission of the oscillating rotation of the external gears 14 and 16. Groove parts 14e and 16e are formed respectively on the end surfaces corresponding to each axial end portion of the inner tooth pin 3 of the external gears 14 and 16 over the whole circumferences of the external gears 14, 16. COPYRIGHT: (C)2011,JPO&INPIT