US Patent 9562601 Gear transmission system

A gear transmission system (20) comprising at least a first cylindrical gear (21) and a second cylindrical gear (22). Each of the first and the second cylindrical gears (21, 22) comprise a plurality of teeth (23, 26). The teeth (23) of the first cylindrical gear (21) having a first tooth flank (24) for contacting a first tooth flank (27) of the teeth (26) of the second cylindrical gear (22) according to a predefined first contact line (30). The first tooth flanks (24, 27) of the teeth (23, 26) of each of the first and second cylindrical gears (21, 22) have a tooth shape and tooth properties determined by the predefined first contact line (30).