A transmission system for hybrid propulsion vehicles comprises a torque convertor, an external output shaft of the torque convertor which is rigidly connected to the output of the convertor and an internal output shaft which is rigidly connected to the input of the convertor, a gearbox which can be selectively connected to drive wheels of the vehicle, a main coupling member for selectively transmitting the movement of the external shaft to the gearbox, an electric motor which can be selectively operated as a motor and as an electrical generator. The transmission system further comprises a downstream coupling member and an upstream coupling member which are arranged upstream and downstream of the torque convertor, respectively, and which are capable of selectively connecting the rotor element to the external shaft and the internal shaft, respectively. The electric motor further comprises a rotor element which is arranged at an opposite distal end of the external shaft with respect to the torque convertor, with the main coupling member being arranged in an intermediate position between the torque convertor and the distal end.

Proposed is a multi-stage transmission in planetary design in a housing (9) for a vehicle comprising at least one electric motor (EM) and comprising three planetary gear sets (RS1, RS2, RS3), wherein a drive (An) can be connected by means of a shift element (K0) to a first shaft (1), and an output (Ab) is connected to a second shaft (2), wherein there are provided four additional shafts (3, 4, 5, 6) and at least five shift elements (B1, K1, K2, K3, K4), through the actuation of which at least eight forward gears (G1, G2, G3, G4, G5, G6, G7, G8) can be implemented. According to the invention, the first element of the first planetary gear set (RS1) is connected to the housing (9), wherein the first shaft (1) is permanently connected to the second element of the first planetary gear set (RS1); wherein the rotor (10) of the electric motor (EM) is connected to the third element of the first planetary gear set (RS1); and wherein the third element of the first planetary gear set (RS1) can be connected by means of at least one shift element (K3, K4) to at least one element of at least one additional planetary gear set (RS2, RS3).

An electric drive direction confirmation system and method for a vehicle are provided. The system and method include receiving a gear selector input signal corresponding to a gear selection from an electronic gear selector on the vehicle, and sending a drive command to temporarily urge the vehicle in a direction corresponding to the gear selection.

A transmission system of a hybrid electric vehicle may include an input shaft connected to an engine, a planetary gear set including a first rotation element operated as an output element, a second rotation element connected to the input shaft and operated as an input element, and a third rotation element operated as another output element, a first motor operably connected to the first rotation element, and selectively connected to a transmission housing, a first motor/generator configured to generate electric energy by receiving torque through the first motor shaft, a second motor shaft being a hollow shaft, disposed at a radial exterior of the first motor shaft without rotational interference with the first motor shaft, and operably connected to the third rotation element so as to receive torque of the engine, and a second motor/generator disposed on the second motor shaft and outputting torque through the second motor shaft.

A machine having a series electric drivetrain system includes an engine to provide mechanical energy to an electric generator, the electric generator able to convert the mechanical energy received from the engine into electrical energy, the electric generator including an input shaft extending through the electric generator, a rotor to rotate on the input shaft, and the input shaft is able to rotate an input gear, an idler gear, a pump drive gear, and a rotor gear, a motor to receive the electrical energy and to produce a rotational output, a single speed ratio direct drive to transfer the rotational output of the motor to a torque output to deliver to a drive shaft, and power electronics to control the electrical energy between the electric generator and the motor and to regulate the rotational output of the motor.

A system and method for controlling engine starting in a hybrid vehicle having first and second electric machines include starting the engine in response to an engine start request using the first electric machine and releasing second electric machine reserved engine starting torque for use in propelling the vehicle. The first electric machine may be controlled to start the engine in response to the first engine start after key-on and when the vehicle speed is below a corresponding threshold, with the second electric machine used when vehicle speed is above the threshold. The first electric machine may be an integrated starter-generator.

A system and method for controlling engine starting in a hybrid vehicle having an engine, a first electric machine selectively coupled to the engine by a first clutch, a second electric machine coupled to the engine, a step-ratio transmission selectively coupled to the electric machine by a second clutch include starting the engine using either the first electric machine or the second electric machine based on engine stop position. The first electric machine may be a low voltage starter motor or integrated starter-generator. The system and method may use the first electric machine when the engine stop position is within a specified range of positions relative to a piston top dead center position associated with higher cranking torques.

A method is provided to control a hybrid powertrain to achieve a desired engine speed in a combustion engine, said powertrain comprising: a gearbox with input and output shafts with the combustion engine connected to the input shaft; a first planetary gear connected to the input shaft and a first main shaft; a second planetary gear connected to the first planetary gear and a second main shaft; first and second electrical machines respectfully connected to the first and second planetary gears; first gear pair connected with the first main shaft; and second gear pair connected with the second main shaft. The method comprises a) ensuring that two rotatable components in the first planetary gear are connected; b) ensuring that all rotatable components in the second planetary gear are disconnected; c) ensuring that a gear is engaged in the first gear pair, d) ensuring that the second gear pair is disconnected; e) controlling the second electrical machine so that a desired torque is achieved in the output shaft; f) controlling the combustion engine to a desired engine speed; and g) controlling the first electrical machine so that a desired total power consumption for the first and the second electrical machines is achieved.

A hybrid powertrain that includes a combustion engine (4) and a gearbox (2) with an input shaft (8) and an output shaft (20); a first planetary gear (10) connected to the input shaft (8); a second planetary gear (12) connected to the first planetary gear (10); a first electrical machine (14) connected to the first planetary gear (10); a second electrical machine (16) connected to the second planetary gear (12); at least one gear pair (G1, 60, 72) connected to the first planetary gear (10) and to the output shaft (20); and at least one gear pair (G2, 66, 78) connected to the second planetary gear (12) and to the output shaft (20), a countershaft (18) provided between the combustion engine (4) and the gearbox (2) so that the engine (4) can be disconnected from the gearbox (2). Also disclosed is a method for controlling the disclosed hybrid powertrain (3). Also a vehicle (1) includes such a gearbox (2), and a method to control such a gearbox (2). Also a computer program (P) to control a gearbox.

A method is provided for moving off of a vehicle with a hybrid powertrain, comprising a combustion engine; a gearbox with input and output shafts; a first planetary gear connected to the input shaft and a first main shaft; a second planetary gear connected to the first planetary gear and a second main shaft; first and second electrical machines respectively connected to the first and second planetary gears and capable of operating each other; one gear pair connected with the first planetary gear and output shaft; and one gear pair connected with the second planetary gear and output shaft. The method comprising, while the combustion engine is in operation: a) ensuring that the rotatable components of the first and second planetary gears are respectively disconnected from each other, b) ensuring that at least one gear is engaged, corresponding to the one gear pair connected with the first planetary gear, and/or the one gear pair connected with the second planetary gear, and c) activating the first and second electrical machines, where total power output from the electrical machines is zero, and so that a torque is generated in the output shaft.