Propeller shaft and rotational power transmission mechanism equipped with this

A propeller shaft comprising a hollow pipe member, a first yoke member and a second yoke member,

• said hollow pipe member having a first end, a second end opposite the first end, and a central portion disposed between said ends, wherein the first and second ends have first and second fittingly receiving portions formed therein, respectively, wherein each of the first fittingly receiving portion and the central portion of said hollow pipe member has a substantially identical internal diameter, which is smaller than an internal diameter of said second fittingly receiving portion;
• wherein the first and second yoke members are attached to the ends of said hollow pipe member, respectively;
• wherein:
• said first yoke member comprises:
• a cylindrical first yoke fitting portion having a first diameter, which is press-fit into an inner circumferential part of the first fittingly receiving portion at said first end of said hollow pipe member, and
• a stopper flange portion, which is provided protruding radially outwardly at a position axially outside said first yoke fitting portion;
• said first yoke fitting portion is press-fit into said inner circumferential part of said first fittingly receiving portion until said one end of said hollow pipe member comes close to said stopper flange portion, so that said first yoke member is attached to said one end of said hollow pipe member;
• said second yoke member comprises a cylindrical second yoke fitting portion having a second diameter which is greater than said first diameter, which is press-fit into an inner circumferential part of the second fittingly receiving portion that is a widened part at the second end of said hollow pipe member;
• said second yoke fitting portion is press-fit into said inner circumferential part of said second fittingly receiving portion, so that said second yoke member is attached to said second end of said hollow pipe member;
• and
• wherein said propeller shaft is configured such that when a compressive force greater than a predetermined force acts axially on said propeller shaft during use, further press-fitting insertion of said first yoke fitting portion is blocked by said stopper flange portion, which hits said first end of said hollow pipe member, and said second yoke fitting portion is press-fit further into an inner circumferential part of said hollow pipe member beyond said second fittingly receiving portion, with said inner circumferential part of said hollow pipe member beyond said second fittingly receiving portion being expanded and destroyed at an axially inward part thereof.