A power transmission apparatus may include a first motor-generator including a first stator fixed to a first housing, and a first rotor; a second motor-generator including a second stator fixed to a second housing and a second rotor; a first planetary gear set including first and third rotation elements connected to the first rotor and a first wheel, respectively, and a third rotation element; a second planetary gear set including fourth, fifth and sixth rotation elements connected to the second rotor, a second wheel, and the third rotation element, respectively; a first clutch selectively locking up the first planetary gear set by selectively connecting two out of the first to third rotation elements; a second clutch selectively locking up the second planetary gear set by selectively connecting two of the fourth to sixth rotation elements; and a brake selectively fixing the third and sixth rotation elements to a third housing.

A vehicle powertrain comprising a first and second electric machines, and a transmission arranged to transmit torque from said electric machines to a driving axle, the transmission comprising: first and second input shafts arranged to be driven by the machines, respectively, a common output shaft, a first gear set comprising:
first and second input gears via which torque is transmittable from the respective input shafts, to the output shaft; a second gear set comprising:
third and fourth input gears via which torque is transmittable from the respective input shafts to the output shaft; means for disconnecting each machine from each other and from the output shaft; an intermediate shaft drivable by the first and/or the second input gear; and an auxiliary gear set having two gear ratios arranged between the intermediate and common output shafts, at least the first gear set being arranged to drive the output shaft via the intermediate shaft and the auxiliary gear set.

A speed-changing device (21) is provided with an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first variator (33), a second variator (34), and a controller (25). The planetary gear mechanism (29) is configured to include a carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first variator (33), and a second sun gear (29C) connected to the output shaft (23). The second variator (34) transmits power transmitted from the first variator (33) to the output shaft (23), or transmits power transmitted from the output shaft (23) to the first variator (33). The controller (25) changes the rotation speed of the first variator (33), thereby changing the rotation speed of the output shaft (23) in relation to the rotation speed of the input shaft (22).

A speed-changing device (21) is provided with an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first variator (33), a second variator (34), and a controller (25). The planetary gear mechanism (29) is configured to include a carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first variator (33), and a second sun gear (29C) connected to the output shaft (23). The second variator (34) transmits power transmitted from the first variator (33) to the output shaft (23), or transmits power transmitted from the output shaft (23) to the first variator (33). The controller (25) changes the rotation speed of the first variator (33), thereby changing the rotation speed of the output shaft (23) in relation to the rotation speed of the input shaft (22).

A traveling mode setting unit configured to cause a shift to shift to a second traveling mode via a third traveling mode based on a traveling state of the vehicle traveling in the first traveling mode. The internal combustion engine control unit includes a derivation unit configured to derive a second rotational speed of the internal combustion engine at the time of transition from the third traveling mode to the second traveling mode based on a first rotational speed of the internal combustion engine at the time of transition from the first traveling mode to the third traveling mode, the traveling state of the vehicle and the second reduction ratio, and the internal combustion engine control unit is configured to control a third rotational speed of the internal combustion engine in the third traveling mode to be a value between the first rotational speed and the second rotational speed.

A drive system includes a first planetary gear set selectively coupled to a first electromagnetic device, a second planetary gear set coupled to a second electromagnetic device and directly coupled to the first planetary gear set, an engine directly coupled to the first planetary gear set with a connecting shaft, and an output shaft coupled to the first planetary gear set. The first and second electromagnetic devices include a first shaft and a second shaft, respectively. The connecting shaft extends through the second electromagnetic device and through the second planetary gear set to the first planetary gear set. The first shaft, the second shaft, the first planetary gear set, the second planetary gear set, the connecting shaft, and the output shaft are radially aligned, forming a straight-thru transmission arrangement.

A vehicular drive device where the damper, the differential gear device, and the first rotary electric machine are disposed side by side on a first axis that is common thereto, the second rotary electric machine is disposed on a second axis that is parallel to the first axis and is different from the first axis, the output device is disposed on a third axis that is parallel to the first axis and is different from the first axis and the second axis, and the first gear mechanism is disposed on a fourth axis that is positioned on a side opposite to the second axis side with respect to a first reference plane that is a plane including both the first axis and the third axis.

A transmission for a vehicle, particularly a skid-steered vehicle, that employs motive power from a prime mover delivered through an input shaft to drive left and right drive shafts at a nominal speed and input power from an electric motor to vary the speed of the left and right drive shafts according to steering commands from a steering control structure. The speed of the left and right drive shafts is directly related to a speed of the input shaft and the nominal speed of the left or right drive shaft is varied upwardly or downwardly by a ratio of the speed of the steering shaft via a speed varying structure. The speed of the left and right drive shafts is simultaneously varied in opposite directions (i.e. upwardly and downwardly) relative to the nominal speed by an equal number of rotations.

A drive system includes a first planetary gear set coupled to a first electromagnetic device, a second planetary gear set coupled to a second electromagnetic device and directly coupled to the first planetary gear set, an engine directly coupled to the first planetary gear set with a connecting shaft, and an output shaft coupled to the first planetary gear set. The first and second electromagnetic devices include a first shaft and a second shaft, respectively. The connecting shaft extends through the second electromagnetic device and through the second planetary gear set to the first planetary gear set. The first shaft, the second shaft, the first planetary gear set, the second planetary gear set, the connecting shaft, and the output shaft are radially aligned, forming a straight-thru transmission arrangement.

An electromechanical power-split system and a method of operating thereof is provided, with a mechanical drive branch including an internal combustion engine (3), and with an electric drive branch including a first motor-generator block (59) including a first motor-generator (1) and a second motor-generator block (60) including a second motor-generator (2), the first motor-generator (1) is connectable to the internal combustion engine (3) and to the second motor-generator (2). The system includes a planetary gearset (4) with dual planet gears (46) and four input/output members for altering the flow ratio of the mechanical and electric drive branch . Each dual planet gear (46) is connected to the four input/output members, which are a first pair of input/output members formed by a first sun gear (41) and a ring gear (44), and a second pair of input/output members formed by a second sun gear (143) and a planet carrier (45).