Hybrid drivetrain including a lockable planetary gear and one-way clutch

An engine (22) drives the satellite carrier (16) of an epicyclic gear train (12) and has a clutch/freewheel (36) which may connect it to the planet (14) thus locking the gear train. A first electrical machine (26) is connected to the planet and has a brake (40) and a second electrical machine (30) is connected to the crown (18) and the wheels (34). On clutch operation the machines drive and generate respectively and the engine drives directly.