Balance shaft having reduced mass and inertia

A balance shaft having first and second journals and at least one counterweight, the first and second journals defining a rotational axis, the at least one counterweight being fixedly coupled to the first and second journals;

• wherein the first journal defines a first journal portion, a second journal portion and a reduced mass portion disposed along the rotational axis between the first and second journal portions, the first journal portion defining a first circumferentially extending bearing surface, the second journal portion defining a second circumferentially extending bearing surface, the reduced mass portion having a body and a stiffening structure, the body being fixed to and spanning between the first and second journal portions, the body being shaped as a cylindrical segment having a third circumferentially extending bearing surface and an inboard surface, the inboard surface being offset from the rotational axis and intersecting the third circumferentially extending bearing surface, the stiffening structure being fixed to and spanning between the first and second journal portions, the stiffening structure being disposed radially inside of a cylindrically-shaped perimeter defined by the first, second and third circumferentially extending bearing surfaces, the stiffening structure being offset from the rotational axis such that the rotational axis is disposed between the body and the stiffening structure so that a void space is formed laterally through the first journal, the void space being bounded on four sides by an inboard surface of the stiffening structure, the inboard surface of the body, an interior surface of the first journal portion and an interior surface of the second journal portion.