A vehicle driving device mounted on a hybrid vehicle includes an engine coupled to wheels of the vehicle via a power transmission path, a transmission mechanism disposed on the power transmission path, a motor generator, a first power transmission mechanism, and a second power transmission mechanism. The motor generator is disposed on a path coupling the engine and transmission mechanism, the first power transmission mechanism is disposed on a path coupling the engine and motor generator, the second power transmission mechanism is disposed on a path coupling the motor generator and transmission mechanism. These paths are included in the power transmission path. The first power transmission mechanism includes a large-diameter rotator and a small-diameter rotator coupled to the engine and the motor generator respectively. The second power transmission mechanism includes a small-diameter rotator and a large-diameter rotator coupled to the motor generator and the transmission mechanism respectively.

A vehicle driving device mounted on a hybrid vehicle includes an engine coupled to wheels of the vehicle via a power transmission path, a transmission mechanism disposed on the power transmission path, a motor generator, a first power transmission mechanism, and a second power transmission mechanism. The motor generator is disposed on a path coupling the engine and transmission mechanism, the first power transmission mechanism is disposed on a path coupling the engine and motor generator, the second power transmission mechanism is disposed on a path coupling the motor generator and transmission mechanism. These paths are included in the power transmission path. The first power transmission mechanism includes a large-diameter rotator and a small-diameter rotator coupled to the engine and the motor generator respectively. The second power transmission mechanism includes a small-diameter rotator and a large-diameter rotator coupled to the motor generator and the transmission mechanism respectively.

A hybrid module includes a first, motor-side pre-assembly group and a second, transmission-side pre-assembly group. A separating clutch is arranged between the motor-side pre-assembly group and the transmission-side pre-assembly group, via which the pre-assembly groups can be connected in a torque-transmitting manner.

A hybrid vehicle includes an engine, a first motor generator, a first clutch, a second clutch, a second motor generator, a power storage device, and an electronic control unit configured to control the engine, the first motor generator, the second motor generator, the first clutch, and the second clutch. The electronic control unit is configured to engage the first clutch and disengage the second clutch such that the first motor generator generates power using power from the engine and the hybrid vehicle runs using power from the second motor generator, when a vehicle speed is equal to or lower than a predetermined vehicle speed.

A hybrid vehicle includes an engine, a first motor generator, a first clutch, a second clutch, a second motor generator, a power storage device, and an electronic control unit configured to control the engine, the first motor generator, the second motor generator, the first clutch, and the second clutch. The electronic control unit is configured to engage the first clutch and disengage the second clutch such that the first motor generator generates power using power from the engine and the hybrid vehicle runs using power from the second motor generator, when a vehicle speed is equal to or lower than a predetermined vehicle speed.

When a speed difference between a maximum rotation speed and an engine rotation speed, that is, an actual rotation speed difference, is equal to or less than a margin rotation speed difference, an engine operating point is changed such that the actual rotation speed difference becomes greater than the margin rotation speed difference. Accordingly, the speed difference between the maximum rotation speed and the engine rotation speed is prevented from becoming equal to or less than the margin rotation speed difference. As a result, since a relatively sufficient margin is secured in the difference between the maximum rotation speed and the engine rotation speed, it is possible to prevent the engine rotation speed from falling into a high-rotation state in which the engine rotation speed exceeds the maximum rotation speed.

A hybrid power system comprises an engine, a hybrid power module, and a dual input shaft speed change mechanism. The hybrid power module comprises a motor, a planetary gear system, and a first clutch. The planetary gear system is provided with at least three rotating shafts, which respectively are: a rotating shaft X1, a rotating shaft X2, and a rotating shaft X3. The first clutch is arranged between any two of the three rotating shafts. A power output shaft of the engine is connected to the rotating shaft X3 or the rotating shaft X1 and to a second input shaft of the dual input shaft speed change mechanism. A rotor of the motor is connected to the rotating shaft X1 or to the rotating shaft X3. The rotating shaft X2 is connected to a first input shaft of the dual input shaft speed change mechanism.

A hybrid power system comprises an engine, a hybrid power module, and a dual input shaft speed change mechanism. The hybrid power module comprises a motor, a planetary gear system, and a first clutch. The planetary gear system is provided with at least three rotating shafts, which respectively are: a rotating shaft X1, a rotating shaft X2, and a rotating shaft X3. The first clutch is arranged between any two of the three rotating shafts. A power output shaft of the engine is connected to the rotating shaft X3 or the rotating shaft X1 and to a second input shaft of the dual input shaft speed change mechanism. A rotor of the motor is connected to the rotating shaft X1 or to the rotating shaft X3. The rotating shaft X2 is connected to a first input shaft of the dual input shaft speed change mechanism.

A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.

A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.