A method for operating a vehicle drivetrain (1) includes proceeding, in the presence of the demand for activation of the engine start-stop function of the vehicle drivetrain (1) and a simultaneously shut-down drive machine (2), from an operating state of the vehicle drivetrain (1) during which a sailing operating function of the vehicle drivetrain (1) is active, during which the drive machine (2) is decoupled from the drive output (3), during which the positively engaging shift element (F) is open and during which a rotational speed (n_ab) of the drive output (3) is higher than a defined rotational speed at which a rotational speed difference between shift element halves of the positively engaging shift element (F) lies within a rotational speed range within which the positively engaging shift element (F) is transferrable into the closed operating state, and actuating the positively engaging shift element (F) in a closing direction no later than when the defined rotational speed is reached.

An electric powertrain includes a first electric motor that has an uninterrupted connection with a drive shaft of a vehicle. The electric powertrain further includes a second electric motor that has an interruptible connection with the drive shaft. In one form, this interruptible connection includes a clutch. The electric powertrain further includes a first gear train in the form of a first planetary gear and a second gear train in the form of a second planetary gear. The first gear train, second gear train, and clutch are arranged downstream from the first electric motor and second electric motor.

Some embodiments are directed to a gearing assembly including a rotary input member, a rotary output member and a gearing arrangement between the input member and the output member selectively engageable to effect a driving engagement between the input member and the output member through at least a first torque connection having a first gear ratio and a second torque connection having a second gear ratio. One of the rotary input member and the rotary output member includes a first shaft and the first torque connection includes a first dog clutch including a dog hub having a hub set of teeth and a surrounding dog ring including a ring set of teeth. The hub and ring sets of teeth are radially projecting and mutually engageable. The dog hub is mounted on the first shaft so as to allow axial movement of the dog hub relative to the shaft.

A transmission (G) includes an input shaft (GW1), an output shaft (GW2), an electric machine (EM), a plurality of planetary gear sets (P1-P3; 2P1-2P5), and gear-implementing shift elements (S1-S6; 2S1-2S5). Via engagement of a first of the gear-implementing shift elements (S1, 2S1), which is a force-locking shift element having a variable torque transmission capacity, the input shaft (GW1) and an element (E1, 22E1) of one of the planetary gear sets (P3; 2P4) can be brought into a fixed rotational speed relationship with respect to each other. Another element (E2, 22E2a, 22E2b) of one of the planetary gear sets (P1, 2P3, 2P5) is permanently connected to a rotor (R) of the electric machine (EM). By engaging an auxiliary shift element (ZS, 2ZSa, 2ZSb), which is a form-locking shift element, the rotor (R) and the input shaft (GW1) can be brought into a fixed rotational speed relationship with respect to each other.

A drive-train for a vehicle with at least one electric drive, which can be coupled via a driveshaft (2) to at least a first transmission ratio stage (i1) and a second transmission ratio stage (i2). At least one shifting mechanism is provided for engaging the transmission ratio stages (i1, i2). To carry out powershifts, the shifting mechanism includes at least one interlocking shifting element (5) and at least one frictional shifting element (6, 6A). Each of the transmission ratio stages (i1, i2) can be engaged by the interlocking shifting element (5) and at least one of the transmission ratio stages (i2) can be engaged both by the interlocking shifting element (5) and by the frictional shifting element (6). Methods for carrying out a powershift, between a frictional shifting element (6, 6A) and an interlocking shifting element (5) in the drive-train, are also disclosed.

A multistage transmission, in particular for a motor vehicle, is provided at least structurally for selecting at least twelve forward transmission gears with different step-up ratios. This multistage transmission has four operatively interconnected planetary gear stages, a transmission input shaft for attaching to an internal combustion engine, a transmission output shaft, for attaching to drive wheels, four clutch units, each of which includes two clutch elements, and three brake units, each of which includes one clutch element.

Methods and systems for an electric drive axle are provided. An electric drive axle, in one example, includes an electric machine rotationally coupled to a gearbox which includes a higher range planetary gear set coupled to a lower range planetary gear set via a clutch. The clutch is configured to selectively rotationally couple an input gear to a sun gear in each of the higher range planetary gear set and the lower range planetary gear set in different positions or selectively rotationally couple a carrier in the higher range planetary gear set to a carrier and a sun gear in the lower range planetary gear set in different positions.

An automatic transmission includes a first planetary gear set, a second planetary gear set, and a first brake. A first sun gear includes a first split sun gear on a drive source side, and a second split sun gear on a side opposite to the drive source. The first spilt sun gear is coupled to the first brake, and is fixed to a transmission case during engagement of the first brake. The second split sun gear is constantly coupled to a second sun gear. An input shaft is constantly coupled to a first carrier while passing through the first split sun gear, and between the first and second split sun gears. An output shaft is constantly coupled to a second carrier.

Devices and methods are provided herein for the transmission of power in motor vehicles. Power is transmitted in a smoother and more efficient manner by splitting torque into two or more torque paths. A continuously variable transmission is provided with a ball variator assembly having two arrays of balls, a planetary gear set coupled thereto and an arrangement of rotatable shafts with multiple gears and clutches that extend the ratio range of the variator. In some embodiments, clutches are coupled to the gear sets to enable synchronous shifting of gear modes.

A power tool is provided which includes a housing assembly; a motor assembly disposed in the housing assembly and having an output shaft; a trigger assembly coupled to the housing assembly and configured for use in actuating the motor assembly; a spindle; and a transmission assembly transmitting rotary power between the motor assembly and the spindle. The transmission assembly comprises a star compound gear train.