A reduction gear configured to decelerate and output rotation of a motor includes two-stage planetary gear mechanisms that are provided side by side in an axial direction of the motor and are each configured of helical gears, and a case made of resin and formed into a cylindrical shape, the case incorporating the two-stage planetary gear mechanisms. At least one of an inner engagement ratio of a sun gear and a pinion gear of the planetary gear mechanism in a first stage and an outer engagement ratio of the pinion gear and a ring gear of the planetary gear mechanism in the first stage is 3.0 or more, and both the inner engagement ratio and the outer engagement ratio are larger than an engagement ratio of the planetary gear mechanism in a second stage.

A drive device for driving wheels of a motor vehicle includes a housing, an electric machine with a stator and rotor, a first output shaft for driving a first wheel, and a second output shaft for driving a second wheel. Via a differential transmission, first and second planetary gearsets are drivable by the rotor. First and second differential shafts transfer drive power from the differential transmission to the first and second planetary gearsets. The first differential shaft is mounted rotatably on an input shaft via bearings and the rotor is connected non-rotationally to the input shaft. A stable and non-buckling bearing of the second differential shaft in relation to the rotor is carried out via further bearings arranged on the second differential shaft or in the first differential shaft. The further bearings are arranged spaced apart from one another at least at a distance of twice an average bearing diameter.

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

An automatic transmission that includes a speed change mechanism including a gear mechanism that can attain a plurality of shift speeds, and a plurality of friction engagement elements that are selectively engaged to attain each shift speed in the gear mechanism; a hydraulic control device that can regulate engagement pressures to be supplied to hydraulic servos of the plurality of friction engagement elements and that can supply lubricating oil that lubricates the speed change mechanism; and a control unit that sends a command about the engagement pressures to the hydraulic control device to control engagement states of the plurality of friction engagement elements.

The present invention is a powertrain for a hybrid vehicle, comprising a driving/receiving machine (20), a thermal engine (10) and engine shaft (12), a speed variation device (14) including an engine epicyclic gear train (24) with a sun gear (34) and a crown (42) which are each connected to the engine shaft (12) by an engine controlled coupling (26, 28) and to a fixed part (40) of the powertrain by a one-way automatic coupling (30, 32). A planet gear carrier (46) and a machine epicyclic gear train (60) are arranged on a shaft (62) substantially parallel to engine shaft (12). The planet gear carrier comprises a sun gear (64), a crown (72), a planet gear carrier (68) and an epicyclic gear train controlled coupling (88). The speed variation device (14) comprises a device (94) for connecting/disconnecting electric machine (20) with machine epicyclic gear train (60).

A control process including the following steps is executed. The control process includes, at the time of switching from series-parallel mode to series mode, a step of reducing an engine torque, a step of releasing a clutch, a step of reducing a reaction torque of a first rotary electric machine and a step of increasing a torque of a second rotary electric machine, and, when synchronization is started and a step of increasing a positive torque of the first MG, a step of starting engagement of a clutch, and, when a rotation speed of the first rotary electric machine and a rotation speed of an engine are synchronous with each other, a step of engaging the clutch.