US Patent 9618108 Gear noise reduction in opposed-piston engines

A quiet-running, multi-layer gear assembly includes a compliant center member sandwiched between a pair of stiff outer members. The compliant center member has an outer peripheral surface with gear teeth. Each of the outer members has an outer peripheral surface with gear teeth disposed in a respective directed axial thrust pattern. The center and outer members are joined on a central hub with their outer peripheral surfaces aligned so as to form a gear assembly with low or no net axial thrust. In some aspects, the compliant center member and the hub include cooperating anti-turn constructions.