| 摘要 |
The present invention relates to a device (10) for varying the speed of a power train of a motor vehicle, in particular of the hybrid type, comprising a drive motor/generator motor (22) and an internal combustion engine (12). The speed variation device comprises: an engine planetary gearset (26) having a sun gear (36) and a ring gear (46), each connected to the shaft of the internal combustion engine by means of a controlled coupling (28, 30) and to the housing (44) of said speed variation device by means of a unidirectional coupling (32, 34), and a motor planetary gearset (58) which is coaxial with the engine planetary gearset (26) and connects this engine planetary gearset to the drive axle (16) via a motion transmission path (78) comprising a wheel (74) supported on the planet carrier (60) and a wheel (76) supported on said drive axle. According to the invention, the motion transmission path (78) comprises a closed band (82) interconnecting the wheels to ensure the transmission of motion in the same direction of rotation between said wheels. |
