Engine balance masses and drives

A balance mass and drive for an engine comprising:

• a crankshaft coupled to a first cylinder bank and a second cylinder bank;
• a planetary gear set including a sun gear, a ring gear and a plurality of pinions mounted on a carrier, the ring gear having an interior that meshes with a first pinion of the plurality of pinions;
• an input coupled to an input gear of the planetary gear set, the input gear being one of the ring gear, the carrier, or the sun gear;
• and
• a balance mass coupled to an output gear of the planetary gear set, the output gear including one of the ring gear, the carrier, or the sun gear, the output gear different from the input gear and configured to drive the balance mass to rotate about a first axis substantially parallel to the crankshaft in a direction opposite the crankshaft.

An engine comprising:

• first and second cylinder banks in a V-configuration coupled to a crankshaft;
• a camshaft sharing an axis of a planetary gear set's sun gear;
• a balance shaft on the axis;
• and
• a first gear of the planetary gear set intermediate the balance shaft and the camshaft, the first gear driving the balance shaft to rotate about a first axis substantially parallel to, and in an opposite direction to, the crankshaft.