Patent ID: 8308599
Filing Date: 2012-11-13
Classification: F16H

Abstract:
1. An eccentric speed reducer comprising: a casing having internal teeth provided on an inner circumference thereof; an external gear housed in the casing and having external teeth provided on an outer circumference thereof for meshing with the internal teeth; a plurality of crankshafts passing through holes formed in the external gear and disposed in a circumferential direction along the inner circumference of the casing, the crankshafts rotating to allow the external gear to eccentrically rotate; a base carrier that rotatably supports one end of the crankshafts; an end carrier that rotatably supports the other end of the crankshafts; and a plurality of struts disposed between the crankshafts in a circumferential direction along the inner circumference of the casing and formed integrally with the base carrier, the struts connecting the base carrier and the end carrier, wherein a tapered side is formed on at least part of a peripheral side surface of the struts, the tapered side extending in a tapered manner in the longitudinal direction of the struts in a direction that is oblique to a direction parallel to a center line passing through the casing so as to connect inner circumferential centers of the casing and in which the struts narrow toward the end carrier, and a tapered side gradient that is the angle of a direction in which the tapered side extends relative to the direction parallel to the center line is at least 3 degrees and at most 6 degrees.