摘要 |
A transmission device includes a drive shaft and two driven shafts. The drive shaft is connected to a wheel and first engagement rotors are arranged therebeside so that the wheel is located therebetween and can rotate together with them. The first engagement rotors having an axial hole in which a driven shaft is rotatably arranged, the first engagement rotors are coupled or uncoupled with second engagement rotors coaxially arranged therebeside, by extracting or retracting, respectively, at least one mobile tooth rotatable in a seat of the first engagement rotors, each driven shaft being keyed to a second engagement rotor. Driving rotors are arranged around the driven shafts between the wheel and the first engagement rotors and are provided with a brake, so that relative rotation of the driving rotors with respect to the first engagement rotors causes extension or retraction of the mobile tooth according to the relative rotation direction. |