Methods and systems are provided for a dual motor electric transmission configured with two dual synchronizers to reduce torque interruption during gear shifting. In one example, a method may include dropping torque of a first electric motor, allowing a first synchronizer to shift from a first gear arrangement to a second gear arrangement, and compensating for dropped torque with a second electric motor. The method may be repeated to shift a second synchronizer from the first gear arrangement to the second gear arrangement, allowing uninterrupted torque supply during gear shifting.

The present invention relates to a hybrid powertrain and method of controlling same, the hybrid powertrain comprising an internal combustion engine; a gearbox with an input and an output shaft; a range gearbox connected to the output shaft; a first planetary gear connected to the input shaft; a second planetary gear connected to the first planetary gear; a first electrical machine connected to the first planetary gear; a second electrical machine connected to the second planetary gear; one 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 range gearbox comprises a third planetary gear with a third sun wheel and a third planetary wheel carrier and a fourth clutch device arranged to connect and disconnect the third sun wheel with/from the third planetary wheel carrier.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox, connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; a first electrical machine, connected to the first planetary gear; a second electrical machine, connected to the second planetary gear; at least one gear pair, connected with the first planetary gear and the output shaft; and at least 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 the steps: a) engaging a gear by way of connecting two rotatable components in the first planetary gear; b) connecting the at least one gear pair, connected with the second planetary gear and the output shaft; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox with the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) controlling the range gearbox from a low range position to a neutral state, in which no torque transmission occurs through the range gearbox; e) controlling two rotatable components in the range gearbox towards achieving a synchronized rotational speed with the assistance of the first electrical machine; f) connecting the rotatable components with the use of a shiftable third clutch device; and g) engaging a gear by way of connecting two rotatable components in the second planetary gear.

A method is provided to control a hybrid powertrain comprising an internal combustion engine; a gearbox with input and output shafts; a range gearbox connected to the output shaft; a first planetary gear, connected to the input shaft; a second planetary gear, connected to the first planetary gear; first and second electrical machines, respectivley connected to the first and second planetary gears; a gear pair connected with the first planetary gear and the output shaft; and a gear pair, connected with the second planetary gear and the output shaft, wherein the internal combustion engine is connected to the input shaft. The method comprises: a) engaging a gear by connecting two rotatable components in the first planetary gear; b) connecting the second or the fourth gear pair; c) connecting a sixth gear pair, arranged between a countershaft and the range gearbox to the countershaft, so that the countershaft is connected with the output shaft via the range gearbox; d) synchronising the rotational speed between two rotatable components in the range gearbox; e) connecting the rotatable components with a shiftable third clutch device; and f) engaging a gear by way of connecting two rotatable components in the second planetary gear.

In a power transmission device in which a first power transmission path is formed by engagement of a first clutch and a dog clutch and a second power transmission path is formed by engagement of a second clutch, the first clutch is released from a state where the first clutch and the dog clutch are engaged, and when a front-rear rotation speed difference of the dog clutch becomes equal to or greater than a predetermined value after the start of a clutch-to-clutch gear shift for engaging the second clutch, complete release control for releasing the first clutch to lower the torque capacity of the first clutch is performed.

A method for changing between a multiplicity of discrete transmission ratio stages in a motorcycle gearbox is provided. In response to a shift demand, during the torque-transmitting connection of a drive shaft of the drive machine to a gearbox input shaft, a gear-selection drum of the transmission is rotatable from a first shifting position to an intermediate position which is situated between the first and a second shifting position, before shifting to the second shift position. In the intermediate position, no drive torque can be transmitted from the gearbox input shaft to a gearbox output shaft. During the gear selection drum movement from the first shifting position and the intermediate position, the drum may be rotated to a rest position in which drive torque can be transmitted from the gearbox input shaft to a gearbox output shaft.

A gas turbine engine with a geared turbofan arrangement with a gearbox in a drive train driven by a turbine, a driving side of the gearbox being driveably connected with a propulsive fan, is provided. The gas turbine includes at least one form locking connection device in a drive train enabling a controlled disengagement of at least one engine part from the drive train in case of a mechanical failure of the gas turbine engine or a part thereof and wherein the at least one form locking connection device is positioned in a torque carrying shaft or a torque carrying part of a shaft and/or wherein the at least one form locking connection device is positioned between the torque bearing coupling of the gearbox with the fan shaft and a torque carrier of the gearbox and at least one load stop for bearing an essential axial load.

The present invention relates to a hybrid powertrain and method of controlling same, the hybrid powertrain comprising an internal combustion engine; a gearbox with an input and an output shaft; a range gearbox connected to the output shaft; a first planetary gear connected to the input shaft; a second planetary gear connected to the first planetary gear; a first electrical machine connected to the first planetary gear; a second electrical machine connected to the second planetary gear; one 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 range gearbox comprises a third planetary gear with a third sun wheel and a third planetary wheel carrier and a fourth clutch device arranged to connect and disconnect the third sun wheel with/from the third planetary wheel carrier.

A method for operating a drive train includes determining target torques for prime movers (1, 2) at least depending on a driver-demanded output torque. When a form-locking shift element (9) is disengaged for a gearchange, the shift element (9) to be disengaged is relieved of load, via an actuation of the prime movers depending on the target torques. The shift element (9) to be disengaged is already actuated with a defined actuating pressure in the direction of disengagement before a theoretical relief from load depending on the target torques, and monitoring determines whether and at which actual torques the shift element (9) to be disengaged begins to move. The actual torques of the prime movers (1, 2), at which the shift element (9) to be disengaged begins to move, are determined as actual torques at which the shift element (9) to be disengaged is actually relieved of load.

An electronic control unit is configured to control a hydraulic pressures of engaging element and disengaging element in accordance with a preset target output shaft torque during a power-on downshift. The electronic control unit is configured to delay a start of decrease in the hydraulic pressure of the disengaging element from a start of a torque phase while maintain the hydraulic pressure of the disengaging element at the start of the torque phase. The electronic control unit is configured to start decreasing the hydraulic pressure of the disengaging element when the electronic control unit determines that overspeed of an input shaft is occurring during the torque phase and a predetermined condition is established.