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 a direction of a 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,
• 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, and
• the connecting portion is provided apart from the first concave portion in the direction of the rotation axis of the shaft part, and an outside diameter of the connecting portion is greater than an outside diameter of the shaft part in a radial direction 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.