A planetary gear train of an automatic transmission for a vehicle may include a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, an input shaft mounted with the first, second, and third planetary gear sets, an output shaft mounted with the fourth planetary gear set, a first shaft, a second shaft directly connected with the input shaft, a third shaft, a fourth shaft, a fifth shaft, a sixth shaft selectively connectable with the fourth shaft, a seventh shaft selectively connectable with the input shaft, an eighth shaft gear-meshed with one shaft among the fourth and seventh shafts, a ninth shaft directly connected with the output shaft, a tenth shaft gear-meshed with a remaining shaft among the fourth and seventh shafts that is not gear-meshed with the eighth shaft, and transfer gears.

When a fourth sun gear is held stationary so as to be unrotatable, a Ravigneaux type planetary gear mechanism transfers power, which has been transferred from an input shaft to a third carrier, to a third sun gear and a third ring gear with the speed of the power increased such that the rotational speed of the third sun gear is higher than the rotational speed of the third ring gear. A clutch, which corresponds to the third sun gear which rotates at a higher speed than that of the third ring gear, is disposed between the Ravigneaux type planetary gear mechanism and a second planetary gear disposed in proximity to the Ravigneaux type planetary gear mechanism with respect to a first planetary gear.

A planetary gear train of an automatic transmission for a vehicle may include an input shaft for receiving an engine torque, an output shaft for outputting a shifted torque, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first shaft, a second shaft directly connected with the input shaft, a third shaft, a fourth shaft, a fifth shaft selectively connectable with the first shaft, a sixth shaft selectively connectable with the fourth shaft, a seventh shaft selectively connectable with the fourth shaft, and an eighth shaft selectively connectable with the fifth shaft and directly connected with the output shaft.

Disclosed is a starting device for a transmission. The starting device includes a drive input shaft provided for coupling the starting device to a drive engine connected upstream from the transmission. An output shaft is configured to connect the starting device to a gearset of the transmission. The drive input shaft and the output shaft can be connected rotationally fixed to one another by means of a first shifting element. An electric machine is provided whose rotor is connected to an intermediate shaft. The intermediate shaft is coupled to the output shaft by way of at least one gear step. In order to realize integration of the upstream drive engine and the electric machine, a second shifting element is also provided which, when actuated, forms a rotationally fixed connection between the intermediate shaft and the drive input shaft.

A planetary gear train of an automatic transmission for vehicles may include an input shaft receiving power of an engine, an output shaft outputting shifted power of the engine, a first planetary gear set including first, second, and third rotating elements, a second planetary gear set including fourth, fifth, and sixth rotating elements, a third planetary gear set including seventh, eighth, and ninth rotating elements, a fourth planetary gear set including tenth, eleventh, and twelfth rotating elements, and seven control elements disposed between the rotating elements and at positions selectively connecting the rotating elements and a transmission housing.

A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting torque of the engine, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first shaft directly connected to the input shaft, a second shaft directly connected to the output shaft, a third shaft, a fourth shaft selectively connectable to the third shaft, a fifth shaft selectively connectable to the third shaft, a sixth shaft, a seventh shaft, and an eighth shaft selectively connectable to the second shaft and the fourth shaft.

A planetary gear train of an automatic transmission for a vehicle may include an input shaft receiving torque of an engine, an output shaft outputting torque, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first shaft, a second shaft, a third shaft, a fourth shaft selectively connectable to the second shaft, and directly connected to the input shaft, a fifth shaft, a sixth shaft, a seventh shaft selectively connectable to the second shaft, and an eighth shaft selectively connectable to the third shaft, and directly connected to the output shaft.

A planetary gear train of an automatic transmission for a vehicle may include an input shaft for receiving an engine torque, an output shaft for outputting a shifted torque, a first planetary gear set, a second planetary gear set, a third planetary gear set, a fourth planetary gear set, a first shaft, a second shaft, a third shaft, a fourth shaft directly connected to the input shaft, a fifth shaft, a sixth shaft selectively connectable to the second shaft, a seventh shaft selectively connectable to the second shaft and the fifth shaft respectively, and an eighth shaft selectively connectable to the fifth shaft and directly connected to the output shaft.

A transmission includes a first hydraulic clutch, a second hydraulic clutch, a third hydraulic clutch, a pump and a controller. The first, second, and third hydraulic clutches are configured to established a parked-ready condition upon engagement of all three clutches. The pump is configured to generate hydraulic fluid pressure. The controller is programmed to, in response to a command to start an engine that powers the pump, engage the first and second clutches. The controller is further programmed to, in response to engagement of the first and second clutches and obtaining operating hydraulic fluid pressure, engage the third clutch.

A planetary gear train may include an input shaft, an output shaft, four planetary gear sets having first to twelfth rotation elements, a first shaft connected with the first rotation element and selectively connectable with a transmission housing, a second shaft interconnecting the second and fourth rotation elements, and connected with the input shaft, a third shaft interconnecting the third rotation element and the tenth rotation element, a fourth shaft connected with the fifth rotation element, a fifth shaft interconnecting the sixth and seventh rotation elements, and selectively connectable with the first shaft, a sixth shaft connected with the eighth rotation element and selectively connectable with the respective third and fourth shaft and selectively connectable with the transmission housing, a seventh shaft interconnecting the ninth and twelfth rotation elements, and selectively connectable with the transmission housing, and an eighth shaft connected with the eleventh rotation element and the output shaft.