A power transmission system of a vehicle may include a first input shaft selectively connected to an engine, a second input shaft as a hollow shaft, enclosing the first input shaft without rotational interference with the first input shaft, and selectively connected to the engine, a speed change portion including first and second planetary gear sets, each planetary gear set including three rotation elements, and four rotation shafts directly connected to at least one rotation element among the rotation elements of the first and second planetary gear sets, a motor/generator, an output shaft, and control elements including two clutches disposed at positions where the first and second input shafts are selectively connected to an output shaft of the engine, and two brakes disposed at positions where two rotation shafts among the four rotation shafts are selectively connected to a transmission housing.

The present invention is related to a vehicle including a motor-generator, a transmission, a shift hydraulic control unit, and a CVT control unit (CVTCU). When a downshift of the transmission is performed without an acceleration request from a driver, the CVTCU sets a pulley thrust at a secondary pulley on the basis of a first lower limit as a lower limit, which is a sum of a fundamental thrust and a first correction thrust. The CVTCU also sets a pulley thrust at a primary pulley on the basis of a second lower limit as a lower limit, which is a sum of the fundamental thrust and a second correction thrust.

A power transmission system of a vehicle may include a first input shaft selectively connected to an engine, a second input shaft as a hollow shaft, enclosing the first input shaft without rotational interference with the first input shaft, and selectively connected to the engine, a speed change portion including first and second planetary gear sets, each planetary gear set including three rotation elements, and four rotation shafts directly connected to at least one rotation element among the rotation elements of the first and second planetary gear sets, a motor/generator, an output shaft, and control elements including two clutches disposed at positions where the first and second input shafts are selectively connected to an output shaft of the engine, and two brakes disposed at positions where two rotation shafts among the four rotation shafts are selectively connected to a transmission housing.

A hybrid vehicle transmission includes input and output shafts, first and second motor/generators, a first planetary gear train in which one rotary element of three rotary elements is connected to the input shaft and another thereof is connected to the first motor/generator, a second planetary gear train in which one of three rotary elements is connected to the output shaft and another thereof is connected to the second motor/generator, a first external gear pair consisting of a first gear, connected to a remaining rotary element of the first planetary gear train, and a second gear, connected to a remaining rotary element of the second planetary gear train, and a second external gear pair consisting of a third gear, connected to the input shaft, and a fourth gear directly connected to one rotary element of the second planetary gear train.

A power train and related vehicle provides multi-mode power transmission. A first continuously variable power source (CVP) may convert rotational power received by the engine for transmission to a second CVP. A variator assembly may receive rotational power from the second CVP at a first input and directly from the engine at a second input. A control assembly may allow the power train to shift between multiple modes, such as a series mode, a split-path mode, and a direct mode. The control assembly may provide seamless shifting between at least two of these modes.

A drive-train has an internal combustion engine (1) with an exhaust gas turbocharger, which drives a vehicle wheel (3) by way of a power-branching transmission (2). When there is an increase of the power demanded from the combustion engine (1) but the exhaust gas turbocharger is not yet producing the required charging pressure, an additional motor (4) is always switched into the drive-train in order to deliver torque to the drive-train.

An electronic control unit of a hybrid vehicle controls an engine and an inverter to execute inverterless traveling. The inverterless traveling is a traveling state where the inverter is set to a gate blocking state, and where a reaction force of a torque that is output by a rotating electric device when the rotating electric device to be rotated by output of the engine generates electric power is applied to an output shaft. The electronic control unit controls a converter to adjust a voltage of an electric power line to a predetermined maximum voltage or a voltage within a predetermined range from the maximum voltage when a shift range of the hybrid vehicle is switched to a non-forward range from a forward range during the inverterless traveling.

A power transmission system of a vehicle may include a first input shaft selectively connected to an engine, a second input shaft as a hollow shaft, enclosing the first input shaft without rotational interference with the first input shaft, and selectively connected to the engine, a speed change portion including first and second planetary gear sets, each planetary gear set including three rotation elements, and four rotation shafts directly connected to at least one rotation element among the rotation elements of the first and second planetary gear sets, a motor/generator, an output shaft, and control elements including two clutches disposed at positions where the first and second input shafts are selectively connected to an output shaft of the engine, and two brakes disposed at positions where two rotation shafts among the four rotation shafts are selectively connected to a transmission housing.

Provided is a method to control a hybrid powertrain to achieve reverse drive, comprising an internal combustion engine, a gearbox with input output shafts; a first planetary gear connected to the input shaft and a second planetary gear; first and second electrical machines respectively connected to the first and second planetary gears; gear pair connected with the first planetary gear and the output shaft and one gear pair connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected with the first planetary gear via the input shaft. The method comprises: a) ensuring the moveable component parts in the first planetary gear are connected with each other and the moveable component parts in the second planetary gear are disconnected from each other; b) ensuring the gear pair connected with the second planetary gear and the output shaft are connected, and the gear pair connected with the first planetary gear and the output shaft are disconnected; and c) controlling the second electrical machine to achieve a negative torque in the output shaft.

A vehicle is provided with a mechanical oil pump (O/P) that is driven by a motor/generator (MG), an electric oil pump (M/O/P) that is driven by a sub-motor (S/M) and a second clutch (CL2) that transmits the drive force of the motor/generator (MG) to left and right drive wheels (LT, RT). When an accelerator pedal is depressed while a brake pedal is still depressed, an integrated controller (10) drives the electric oil pump (M/O/P) before the brake pedal is released, and oil pressure supplied to the second clutch (CL2) is increased.