Coupling member of power transmission apparatus

摘要

A coupling member for a power transmission apparatus, connected to a fiber reinforced plastic cylindrical drive shaft, is comprised of a substantially cylindrical fitting portion to be press fitted into the drive shaft. The fitting portion is comprised of a serration portion formed in the axial direction on an outer circumferential surface of the fitting portion. The edge of the fitting portion has an inclined guide surface. The tip area of the guide surface is a guide portion with a smaller outer diameter than an inner diameter of an end portion of the drive shaft. An area between the guide portion and the outer circumferential surface of the fitting portion is a cut away portion continuing from the serration portion. A tapering angle of the cut away portion is smaller than of the guide portion.