A motor, a reduction gear, a differential gear, and a housing having a cylindrical shape are included. The motor has a rotor and a stator. The rotor rotates around a motor axis. The stator faces the rotor in a radial direction with a gap interposed between them. The reduction gear includes a planetary gear mechanism, and can increase rotational power output from the motor according to a reduction ratio. The differential gear distributes and outputs the rotational power from the reduction gear. The housing houses the motor, the reduction gear, and the differential gear arranged in an axial direction with the motor axis as a common rotation axis. The housing includes a first attachment portion and a second attachment portion arranged on an outer peripheral surface. The first attachment portion and the second attachment portion are arranged on the opposite sides in a direction perpendicular to the axial direction with respect to the motor axis.

A power transmission device includes a bearing, a differential mechanism, a case that houses the differential mechanism, a pinion gear supported by the case, a wall part that overlaps the case in an axial direction, a plate that is provided between the wall part and the case in the axial direction, and that supports the case with the bearing being interposed, and a parking pawl that is rotatably fixed to the plate in a position that overlaps the plate in the axial direction.

A power transmission device includes a box, a case disposed in the box, a differential mechanism housed in the case, and a planetary gear mechanism disposed in the box and supported by the case. The planetary gear mechanism includes a sun gear and a pinion gear that engages with the sun gear. The box has a shelf part above a horizontal line that passes through a revolution center of the pinion gear. The shelf part is arranged at a position that does not overlap the sun gear when viewed from radially above.

A power transmission device includes a motor, a gear mechanism connected downstream of the motor and lubricated by oil, and a box. The box has a wall part that covers an outer circumference of the gear mechanism, and a jacket part that covers an outer circumference of the wall part. A cooling chamber, in which cooling liquid is introduced, is formed between the wall part and the jacket part. The cooling chamber includes a portion that overlaps with the gear mechanism when seen from a radial direction, and a portion that overlaps the gear mechanism when seen from an axial direction.

A gear unit for a powertrain and gear unit having a stepped planetary gearset, a first gear shifting element and a second gear shifting element. The stepped planetary gearset has a first sun gear, a first ring gear, a second ring gear, and a plurality of stepped planet gears rotatably mounted at a first planet carrier. The first sun gear is connected to an electric machine. The first planet carrier is fixedly connected to a housing with respect to rotation. The first gear shifting element connects the second ring gear to an output shaft of the gear unit in a closed state, and the second gear shifting element connects the first ring gear to the output shaft of the gear unit in a closed to state, and one of the two gear shifting elements) is in the closed state for driving the output shaft in rotation.

A gear unit for a powertrain of a vehicle includes a stepped planetary gearset, a first gear shifting element and a second gear shifting element. The stepped planetary gearset has at least a first ring gear, a second ring gear and a plurality of stepped planet gears rotatably mounted at a first planet carrier. The first planet carrier drivingly connects to an electric machine. The second ring gear is connected to an output shaft of the gear unit so as to be fixed with respect to rotation relative to it. The first gear shifting element fixes the first ring gear relative to a housing in a closed state, and the second gear shifting element brings the stepped planetary gearset into direct drive in a closed state. One of the two gear shifting elements is in the closed state for driving the output shaft in rotation.

A powertrain of a vehicle includes a stepped planetary gearset, a first gear shifting element and a second gear shifting element. The stepped planetary gearset has a first sun gear and a second sun gear, a first ring gear and a plurality of stepped planet gears rotatably mounted at a first planet carrier. The first ring gear is configured to drivingly connect to an electric machine. The first planet carrier is connectable to an output shaft of the gear unit to be fixed with respect to relative rotation. The first gear shifting element is configured to fix the second sun gear relative to a housing in a closed state, and the second gear shifting element is configured to fix the first sun gear relative to the housing in a closed state. One of the two gear shifting elements is in the closed state for driving the output shaft in rotation.

A gear unit includes: a stepped planetary gearset, and first and second gear shifting elements. The stepped planetary gearset has first and second sun gears, a first ring gear and a plurality of stepped planet gears rotatably mounted at a first planet carrier. The first ring gear is connected to an output shaft of the gear unit thus being fixed with respect to rotation relative to it. The first planet carrier is connected to a housing and fixed with respect to rotation relative to it. The first gear shifting element drivingly connects the second sun gear to an electric machine in a closed state, and the second gear shifting element drivingly connects the first sun gear to an electric machine in a closed state. One of the two gear shifting elements is in the closed state for driving the output shaft in rotation.

A gear unit for a powertrain of a motor vehicle includes a drive shaft, a driven shaft, first and second planetary gearsets and first and second shifting elements. The first shifting element drivingly connects the drive shaft to an input of the first planetary gearset, and the second shifting element drivingly connects the drive shaft to an input of the second planetary gearset. An output element of the second planetary gearset is connected to the input of the first planetary gearset to be fixed with respect to rotation relative to it, and an output of the first planetary gearset is at least indirectly drivingly connected to the driven shaft. A shared element is fixed with respect to relative rotation and, with an inner toothing, forms a ring gear of the first planetary gearset and, with an outer toothing, forms a sun gear of the second planetary gearset

A hybrid vehicle includes an engine that drives first wheel, and a motor that drives second wheel. The hybrid vehicle includes (1) a minute speed launch support mode where the hybrid vehicle is driven only by the motor as a drive source, (2) a sudden launch support mode where the hybrid vehicle is driven by the engine and motor as the drive source, and (3) a smooth launch support mode where the hybrid vehicle is driven only by the motor as the drive source in an early stage, is driven by the engine and motor in a middle stage, and is driven only by the engine in a late stage, and if an operation amount of an acceleration instruction unit is not 0 or is substantially not 0, any one of the support modes is executed according to an operation status of the acceleration instruction unit.