US Patent 7297086 Epicyclic gear systems

An epicyclic gear system (A, B), which is highly compact, yet capable of transferring substantial torque, includes a sun gear (2, 62), a ring gear (4, 64) around the sun gear, and planet gears (6, 8, 66, 68) organized in two rows between the sun and ring gears. In addition, the gear system has a carrier (10, 70) provided with one or two flanges (14, 72, 74) and flexible pins (20, 22, 80, 82) around which the planet gears revolve. The planet gears are mounted on the pins in a double cantilever arrangement to improve the mesh with the sun and ring gears and achieve better load distribution.