Patent ID: 7037230

Claim:
A speed transmission apparatus, arranged between a drive engine and a drivable receiving device, comprising a first rotary casing arranged so as to be able to turn about a first axis of rotation, a first epicyclic gear train which is arranged at least partially in said first rotary casing, a second rotary casing arranged so as to be able to rotate about a fifth axis of rotation, a second epicyclic gear train which is arranged at least partially in said second rotary casing, said first and said second epicyclic gear train forming a double gear train located between a driving input connected to the drive engine and an output shaft arranged so as to be able to rotate about a second axis of rotation and connected to the drivable receiving device, said double gear train establishing between the driving input and the output shaft a transmission ratio between an input rotation speed and an output rotation speed, said first epicyclic gear train comprising an interposed output shaft mounted so as to turn with it, and said second epicyclic gear train comprising an interposed input shaft mounted so as to rotate with it, a first rotation transmission between said first and said second gear train comprising a transmission shaft which comes into engagement with each of said first and second rotary casings and which forms a first intermediate shaft able to rotate about a third axis of rotation, a second rotation transmission between said first and second gear trains which is arranged between said interposed output shaft of the first gear train and said interposed input shaft of said second gear train, and which comprises a second intermediary shaft able to rotate about a fourth axis of rotation, a first electric motor brake acting on one of said first and second intermediate shafts and capable of modifying a speed of rotation thereof, and control means electrically connected to and controlling the first motor brake so as to be able continuously to modify the speed of rotation of said one of said first and second intermediate shafts on which the first electric motor brake acts and, thus, also the transmission ratio between said input rotation speed and said output rotation speed.