ELECTRIC MACHINE GEARBOX AND ENGINE STARTER AND POWER GENERATOR INCLUDING GEARBOX

A gearbox arrangement of an electric machine of an engine includes a planetary gear arrangement configured to receive rotational input from the electric machine and from the engine and to mechanically couple the electric machine and the engine in first and second power flow directions, the planetary gear set comprising a ring gear, a ring brake, a free-wheel clutch attachable to a fixed structure and the ring brake, the tree-wheel clutch permitting rotation of the ring brake in a first direction and preventing rotation of the ring brake in an opposite second direction, and an arrangement for moving the ring gear between a first position in which the ring gear is non-rotatably engaged with the ring brake and a second position in which the ring gear is non-rotatably engaged with the carrier. An engine starter and power generator device Is also provided.