Engine crankshaft assembly with internal reinforcement structure

A crankshaft assembly having an internal reinforcement structure, a method for making/using such a crankshaft assembly, and an internal combustion engine equipped with such a crankshaft assembly are presented. A crankshaft body formed from a first material includes a plurality of bearing journals that are coaxial to one another to rotate on a crankshaft axis and spaced apart from one another along a length of the crankshaft. Each bearing journal has an internal journal cavity. The plurality of crankpins are spaced apart from each other in a longitudinal direction and are axially offset from a rotational axis of the crankshaft. Each crankpin has an internal crankpin cavity. A plurality of crank webs project radially from the crankshaft axis and interconnect the bearing journals and the crankpins. Each crank web has an internal web cavity. A stiffener formed of a second material is disposed within the journal cavity, the crankpin cavity, and/or the web cavity, the second material having an elastic modulus great