Provided is a polypropylene-based resin composition which gives uniform and fine cells and from which a foamed sheet and thermoform excellent in appearance, thermoformability, impact resistance, lightness, stiffness, heat resistance, heat insulating properties, oil resistance and the like can be produced. Opposite side face splines, which, by meshing with each other, couple the hub spindle and an outer ring of a constant velocity joint torque-transmittably, are respectively formed on an end face of the hub spindle and on an end face of the outer ring of the constant velocity joint which is abutted against this end face. The plurality of air nozzles are positioned perpendicular to the transfer object to stop andor engage the transfer object in a rest position.