A shift group for a power shift transmission includes a branching unit having a planetary stage and a branching coupling assigned to the planetary stage. The branching unit is designed such that a mechanical power is transmitted from a first shaft to a second shaft. A first power path and a second power path are provided. In a first shifting state, the power is transmitted via the first or the second power path, and in a second shifting state, the power is transmitted via both the first and the second power paths. The shift group also includes individually shiftable transmission units each comprising a different transmission ratio, where a first transmission unit is disposed in the first power path and a second and a third transmission unit are disposed in the second power path.

A powertrain may include an input shaft; a drive pulley and a driven pulley engaged to each other by a belt; a forward/backward switching mechanism provided to selectively switch a direction of power from the input shaft to the drive pulley by a plurality of friction members and transmit the power; a gear train provided to transmit the power of the input shaft to a rotation shaft of the driven pulley without passing through the drive pulley; and another friction member provided to interrupt a power transmission path of the gear train.

A shift group for a power shift transmission includes a summation unit having a planetary stage and a branching coupling assigned to the planetary stage. The summation unit is designed such that a mechanical power is transmitted from a first shaft to a second shaft. A first power path and a second power path are provided. In a first shifting state, the power is transmitted via the first or the second power path, and in a second shifting state, the power is transmitted via both the first and the second power paths. The shift group also includes individually shiftable transmission units each comprising a different transmission ratio, where a first transmission unit is disposed in the first power path and a second and a third transmission unit are disposed in the second power path.

A shift group for a power shift transmission includes a summation unit having a planetary stage and a branching coupling assigned to the planetary stage. The summation unit is designed such that a mechanical power is transmitted from a first shaft to a second shaft. A first power path and a second power path are provided. In a first shifting state, the power is transmitted via the first or the second power path, and in a second shifting state, the power is transmitted via both the first and the second power paths. The shift group also includes individually shiftable transmission units each comprising a different transmission ratio, where a first transmission unit is disposed in the first power path and a second and a third transmission unit are disposed in the second power path.

The present invention relates to a transmission for a vehicle, and more particularly, to a compound transmission of combining a differential gear and a continuously variable transmission, which transmits power through the differential gear and a transmission gear at a low speed and transmits the power through the continuously variable transmission and the differential gear at a high speed. According to the present invention, the shifting is performed through the differential gear unit at a low stage requiring large torque and low rpm and performs the shifting through the continuously variable transmission at a high stage requiring relatively small torque and high rpm to provide optimum shifting efficiency by collecting only advantageous of the respective units.

The present invention relates to a transmission for a vehicle, and more particularly, to a compound transmission of combining a differential gear and a continuously variable transmission, which transmits power through the differential gear and a transmission gear at a low speed and transmits the power through the continuously variable transmission and the differential gear at a high speed. According to the present invention, the shifting is performed through the differential gear unit at a low stage requiring large torque and low rpm and performs the shifting through the continuously variable transmission at a high stage requiring relatively small torque and high rpm to provide optimum shifting efficiency by collecting only advantageous of the respective units.

A powertrain for a hybrid vehicle may include a planetary gear set; a first motor-generator connected to one rotation element of the planetary gear set and an engine connected to the first motor-generator; a second motor-generator connected to another rotation element of the planetary gear set; a second clutch connected to the other rotation element of the planetary gear set and a second drive gear connected to the second clutch; a first clutch connected to the rotation element to which the first motor-generator is connected and a first drive gear connected to the first clutch; and an output shaft having a first driven gear and a second driven gear engaged in the first drive gear and the second drive gear, respectively.

A powertrain for a hybrid vehicle may include a planetary gear set; a first motor-generator connected to one rotation element of the planetary gear set and an engine connected to the first motor-generator; a second motor-generator connected to another rotation element of the planetary gear set; a second clutch connected to the other rotation element of the planetary gear set and a second drive gear connected to the second clutch; a first clutch connected to the rotation element to which the first motor-generator is connected and a first drive gear connected to the first clutch; and an output shaft having a first driven gear and a second driven gear engaged in the first drive gear and the second drive gear, respectively.

An automatic torque transmission with one or more stages, where each stage has a number of available gear ratios. There is a planetary gear train comprising a planet gear on a planet gear carrier, a sun gear, and a ring gear, wherein an input to the planetary gear train is through the planet gear carrier, and wherein the planet gear is configured to drive the sun gear at higher speed and lower torque, and the ring gear at lower speed and higher torque. There is a first differential gear train having a first input side, a second input side, and an output, wherein the sun gear is coupled to the first input side of the first differential gear train and the ring gear is coupled to the second input side of the first differential gear train, thereby combining two inputs into a single output. A brake clutch is configured to be selectively coupled to the ring gear, to provide selective braking of the ring gear so as to selectively transfer drive from the ring gear to the sun gear. A one-way clutch is configured to be selectively engaged or disengaged from the sun gear, to selectively prevent rotation of the sun gear in one direction. The output of the differential gear train is coupled to either another stage of the transmission or to an output differential gear train. The output differential gear train is configured to be locked for forward drive or coupled to a housing for reverse drive. With the one-way clutch disengaged the sun gear will freewheel by rotating in reverse, with no output.

A continuously variable powertrain for vehicles may include an input shaft, a planetary gear train connected to the input shaft, a first clutch disposed to selectively connect rotation elements of the planetary gear set, a drive pulley disposed to receive power from the input shaft through the planetary gear set, a driven pulley connected to the drive pulley by a belt, an output shaft disposed concentrically with an axis of rotation of the driven pulley, a gear train connected between the input shaft and the output shaft in an external gear form, a second clutch disposed to transmit power from the input shaft through the gear train to the output shaft, and a third clutch disposed to transmit power from the driven pulley to the output shaft.