Patent attributes
A power transmission shaft is interposed between a first shaft section and a second shaft section. The power transmission shaft comprises: a cylindrical section rotated integrally with a shaft section and formed cylindrically; a through hole disposed in the cylindrical section and penetrated radially with respect to a rotational axial line, each of a pair of vehicle side rotational shaft sections having an engagement groove disposed on an outer peripheral side of the pair of vehicle side rotational shaft sections and extended in a direction around the rotational axial line and the engagement groove being exposed from the through hole; and a retaining ring (circlip) disposed to enclose at least a portion of the outer peripheral side of the cylindrical section, a portion of the retaining ring being inserted into the through hole from the outer peripheral side of the cylindrical section and being engaged with the engagement groove.