Continuously variable transmission for hybrid motor vehicles

1. A motor vehicle transmission, comprising an input shaft ( 27 ) adapted to be drivingly connected to an output shaft of an internal combustion engine, a variator ( 22 , 40 ) having a first and a second input/output shaft ( 21 , 41 ), a planetary gear train ( 1 ) having at least two interconnected planetary gear sets ( 2 , 3 ) for splitting power between said input shaft ( 27 ) and one of said input/output shafts ( 21 , 41 ) when transmitting torque to an output of the transmission, first clutch means ( 13 ) having an engaged position establishing torque transmission between one of said input/output shafts and said output means via said planetary gear train and a disengaged position disrupting said torque transmission, a gear train ( 42 , 34 , 31 ) arranged to enable torque transmission from one of said first and second input/output shafts to said output means thereby by-passing said planetary gear train and second clutch means ( 39 ) having an engaged position establishing said last mentioned torque transmission and a disengaged position disrupting said last mentioned torque transmission, and wherein said gear train comprises a first gear wheel ( 42 ) drivable by one of said input/output shafts ( 41 ), a second gear wheel ( 34 ) mounted on an intermediate shaft ( 33 ) and drivable by said first gear wheel and a third gear wheel ( 31 ) rotatably journalled on the intermediate shaft and lockable on the intermediate shaft by said second clutch means ( 39 ) to transmit torque from one of said input-output shafts to said output, wherein said output is a gear wheel ( 35 ) which is non-rotatably journalled relative to said third gear wheel ( 31 ) and meshes with a crown wheel ( 36 ) of a differential.

2. A transmission according to claim 1 wherein said gear train comprises a fourth gear wheel ( 12 ) which is rotatably journalled on a shaft ( 11 ) and lockable on this shaft by said first clutch means ( 13 ) to transmit torque from one of the input-output shafts ( 21 , 41 ) to the planetary gear train ( 1 ).

3. A transmission according to claim 2 wherein said first clutch means ( 13 ) are double acting so as to enable locking of said shaft ( 11 ) to a stationary element ( 15 ) of the transmission.

4. A transmission according to claims 1 wherein said second clutch means ( 39 ) has a position in which said third gear wheel ( 31 ) is rotatable on the intermediate shaft and the intermediate shaft ( 33 ) is locked to a stationary element of the transmission.

5. A transmission according to claim 2 wherein the fourth gear wheel ( 12 ) is rotatably journalled on a hollow shaft ( 11 ) which is arranged concentrically with said input shaft ( 27 ) and is drivingly connected to a sun gear ( 10 ) of the first planetary gear set ( 2 ), that a sun gear ( 20 ) of the second planetary gear set ( 3 ) is drivingly connected to one of the input/output shafts ( 21 ), that a planet carrier ( 15 ) of the first planetary gear set is non-rotatably connected to a ring gear ( 25 ) of the second planetary gear set and to said input shaft ( 27 ) and that a planet carrier ( 24 ) of the second planetary gear set and a ring gear ( 16 ) of the first planetary gear set are non-rotatably connected to a gear wheel ( 30 ) transmitting torque to said third gear wheel ( 31 ).

6. A transmission according to claim 5 wherein said gear wheel ( 30 ) transmitting torque to said third gear wheel ( 31 ) is a ring gear arranged concentrically with the planetary gear train ( 1 ) and with external teeth meshing with the teeth of said third gear wheel.

7. A transmission according to claim 1 wherein said first and second clutch means ( 13 , 39 ) are dog clutches without synchronizers.

8. A transmission according to claim 1 wherein the variator comprises a first and a second electric machine ( 22 , 40 ), each one being arranged to operate either as a generator or as a driving motor.

9. A motor vehicle transmission, comprising an input shaft ( 27 ) adapted to be drivingly connected to an output shaft of an internal combustion engine, a variator ( 22 , 40 ) having a first and a second input/output shaft ( 21 , 41 ), a planetary gear train ( 1 ) having at least two interconnected planetary gear sets ( 2 , 3 ) for splitting power between said input shaft ( 27 ) and one of said input/output shafts ( 21 , 41 ) when transmitting torque to an output of the transmission, first clutch means ( 13 ) having an engaged position establishing torque transmission between one of said input/output shafts and said output means via said planetary gear train and a disengaged position disrupting said torque transmission, said first clutch means ( 13 ) being double acting so as to enable locking of said shaft ( 11 ) to a stationary element ( 15 ) of the transmission, a gear train ( 42 , 34 , 31 ) arranged to enable torque transmission from one of said first and second input/output shafts to said output means thereby by-passing said planetary gear train and second clutch means ( 39 ) having an engaged position establishing said last mentioned torque transmission and a disengaged position disrupting said last mentioned torque transmission, and wherein said gear train comprises a first gear wheel ( 42 ) drivable by one of said input/output shafts ( 41 ), a second gear wheel ( 34 ) mounted on an intermediate shaft ( 33 ) and drivable by said first gear wheel and a gear wheel ( 31 ) rotatably journalled on the intermediate shaft and lockable on the intermediate shaft by said second clutch means ( 39 ) to transmit torque from one of said input-output shafts to said output.

10. A motor vehicle transmission, comprising an input shaft ( 27 ) adapted to be drivingly connected to an output shaft of an internal combustion engine, a variator ( 22 , 40 ) having a first and a second input/output shaft ( 21 , 41 ), a planetary gear train ( 1 ) having at least two interconnected planetary gear sets ( 2 , 3 ) for splitting power between said input shaft ( 27 ) and one of said input/output shafts ( 21 , 41 ) when transmitting torque to an output of the transmission, first clutch means ( 13 ) having an engaged position establishing torque transmission between one of said input/output shafts and said output means via said planetary gear train and a disengaged position disrupting said torque transmission, a gear train ( 42 , 34 , 31 ) arranged to enable torque transmission from one of said first and second input/output shafts to said output means thereby by-passing said planetary gear train and second clutch means ( 39 ) having an engaged position establishing said last mentioned torque transmission and a disengaged position disrupting said last mentioned torque transmission, said second clutch means ( 39 ) having a position in which said third gear wheel ( 31 ) is rotatable on the intermediate shaft and the intermediate shaft ( 33 ) is locked to a stationary element ( 15 ) of the transmission, and wherein said gear train comprises a first gear wheel ( 42 ) drivable by one of said input/output shafts ( 41 ), a second gear wheel ( 34 ) mounted on an intermediate shaft ( 33 ) and drivable by said first gear wheel and a gear wheel ( 31 ) rotatably journalled on the intermediate shaft and lockable on the intermediate shaft by said second clutch means ( 39 ) to transmit torque from one of said input-output shafts to said output.