A method for operating a transmission, wherein the transmission is shifted from an original gear to a target gear, the method including: setting one of the shift elements located in a power flow of the transmission essentially load-free by use of an electric motor; opening the shift element essentially load-free in the first step; synchronizing a rotational speed between two shafts of the transmission by the electric motor or by a torque at the transmission input shaft, the two shafts to be connected in the target gear through a shift element not in the power flow of the transmission at the first step; and locking the shift element between the two shafts synchronized in the third step; wherein a change to a transmission ratio between the original gear and the target gear is greater than a change between the original gear and an adjacent gear.

A control system of a vehicle includes an automatic transmission provided with a plurality of friction engagement elements changeable between engaged and disengaged states, and configured to form a plurality of gear stages by changing a combination of three friction engagement elements to be selectively engaged among the friction engagement elements, and a controller which controls the change between the engaged and disengaged states of each friction engagement element. The controller performs a neutral control in which, for setting the automatic transmission to a neutral state in which a driving force of a drive source is not transmitted to driving wheels, while two of the three friction engagement elements engaged when forming each gear stage are kept engaged, the remaining one of the three friction engagement element is disengaged. The two friction engagement elements engaged during the neutral control are common in at least two adjacent gear stages.

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.

Provided are gearboxes including compound planet gear assemblies as well as methods of using such gearboxes. A gearbox includes at least a first ring gear and a second ring gear. Depending on the current gear selection, one of these ring gears may be engaged with a shifting mechanism or not engaged with any ring gears when in a neutral gear. The first ring gear may be constantly engaged with a first planet gear of a compound planet gear assembly, while the second ring gear may be constantly engaged with a second planet gear of the same compound planet gear assembly. The first planet gear may be also engaged with a sun gear coupled to a shaft. Another shaft is coupled to the shifting mechanism. Different gear selections of the gearbox engage different ring gears to the shifting mechanism thereby changing the rotational speed ratio of the two shafts.

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.

Systems and methods for an electric powertrain. The method, in one example, includes responsive to receiving a shift command, engaging a second friction clutch while disengaging a first friction clutch to transition from a first operating gear ratio to a second operating gear ratio. The method, further includes during the gear ratio transition, operating a traction motor under a peak condition, the peak condition denotes a condition where the motor speed is greater than a maximum continuous torque curve of the motor.

An electric motorcycle includes an electric motor, a manual transmission, a shift drum potentiometer, and an ECU. When it is determined based on an input from the shift drum potentiometer that a transmission manipulation has been performed, the ECU executes a first control operation when switching from a power transmission state to a power cut state and executes a second control operation when returning from the power cut state to the power transmission state. In the first control operation, the ECU controls an operation of the electric motor to facilitate disengagement of an engagement mechanism from a gear train of the manual transmission. In the second control operation, for facilitating engagement of the engagement mechanism with a different gear train, the ECU controls the operation of the electric motor to make a revolving speed of the different gear train close to the revolving speed of the engagement mechanism.

Provided are gearboxes including compound planet gear assemblies as well as methods of using such gearboxes. A gearbox includes at least a first ring gear and a second ring gear. Depending on the current gear selection, one of these ring gears may be engaged with a shifting mechanism or not engaged with any ring gears when in a neutral gear. The first ring gear may be constantly engaged with a first planet gear of a compound planet gear assembly, while the second ring gear may be constantly engaged with a second planet gear of the same compound planet gear assembly. The first planet gear may be also engaged with a sun gear coupled to a shaft. Another shaft is coupled to the shifting mechanism. Different gear selections of the gearbox engage different ring gears to the shifting mechanism thereby changing the rotational speed ratio of the two shafts.

A method is provided to control a hybrid powertrain comprising engaging gears corresponding to a first gear pair connected with a first planetary gear in a gearbox with a first coupling device connecting two rotatable components in the first planetary gear; activating a second electrical machine to generate a propulsion torque on the output shaft via a second gear pair connected with a second planetary gear and the output shaft; disconnecting the first gear pair from the countershaft, by controlling the first electrical machine and a combustion engine connected with the first planetary gear to achieve a substantially zero torque state between the first gear pair; connecting the first gear pair to the countershaft, by controlling the combustion engine to achieve a synchronous rotational speed between the first gear pair; and activating the combustion engine and/or the first electrical machine to generate a propulsion torque on the output shaft.

Provided are gearboxes including compound planet gear assemblies as well as methods of using such gearboxes. A gearbox includes at least a first ring gear and a second ring gear. Depending on the current gear selection, one of these ring gears may be engaged with a shifting mechanism or not engaged with any ring gears when in a neutral gear. The first ring gear may be constantly engaged with a first planet gear of a compound planet gear assembly, while the second ring gear may be constantly engaged with a second planet gear of the same compound planet gear assembly. The first planet gear may be also engaged with a sun gear coupled to a shaft. Another shaft is coupled to the shifting mechanism. Different gear selections of the gearbox engage different ring gears to the shifting mechanism thereby changing the rotational speed ratio of the two shafts.