Propeller shaft and yoke structure of universal joint used for the propeller shaft

A propeller shaft comprising:

• a shaft part;
• a first yoke having a fixing portion, a connecting portion, a first yoke portion and a first concave portion, wherein
• the first yoke is connected, at the connecting portion, to one end of the shaft part in the direction of the rotation axis of the shaft part,
• the first yoke portion is provided at the fixing portion, and has a shape that extends in the direction of the rotation axis of the shaft part, and
• the first concave portion is provided at the fixing portion so as to accommodate thereon an outer circumferential surface of a fastening tool that fastens the securing member, separate from the connecting portion in the direction of the rotation axis of the shaft part, and has a concave shape that opens toward a radial direction outer side of the rotation axis of the shaft part;
• a second yoke having a flange and a second yoke portion, wherein
• the flange has a bolt insertion hole into which a securing member is inserted, and is connected to a second shaft part of a vehicle side by the securing member, and
• the second yoke portion is provided at the flange, and has a shape that extends in a direction of a rotation axis of the shaft part;
• and
• a cruciform shaft coupling the first yoke portion with the second yoke portion.