A transmission system is provided that includes a mechanical reverse assembly designed to selectively mechanically couple a reverse gearset to an output shaft of an electric machine and a first primary shaft. In the mechanical reverse assembly, a coupling device may be automatically shifted to attach the reverse gearset to the first primary shaft in a reverse drive configuration in any of a hybrid mode, a full electric vehicle (EV) mode, and a full internal combustion engine (ICE) mode.

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.

A method for operating a dual-clutch transmission includes, to resolve a respective tooth-on-tooth position between a toothing of a sliding sleeve and a toothing of a gear wheel during an engaging operation for the respective gear, a relative rotation between the toothing of the sliding sleeve and the toothing of the gear wheel is effected by a twisting torque which acts on the respective gear where the twisting torque is a same size for all of the plurality of gears.

An electric powertrain for a vehicle provides electric propulsion to the vehicle. The electric powertrain includes a first electric motor linked to a first gear module through a motor shaft, said first gear module including a primary shaft on which are arranged a first primary gear and a second primary gear, a second gear module including a secondary shaft on which are arranged a first secondary gear that is meshing with the second primary gear, at least one countershaft on which are arranged a first quaternary gear and a second quaternary gear, a coupling member arranged at the first extremity of the primary shaft.

A shift control method for the vehicle with a DCT may include a start determining step of determining, by a TCU, whether the DCT may have entered a power-on down shift inertia phase, a clutch control step of controlling a release-side clutch by determining, by the TCU, a release-side clutch control torque, when the DCT enters the power-on down shift inertia phase, a limit determining step of determining whether the release-side clutch control torque is reduced below a predetermined minimum control torque, while the TCU performs the clutch control step, and an engine-assistance requesting step of requesting an ECU to set an engine-torque rise request amount in proportion to a release-side clutch control torque reduction amount that is additionally required by the TCU, when it is determined in the limit determining step that the release-side clutch control torque is reduced below the minimum control torque.

A transmission unit includes: input shafts; output shafts configured to transmit with a corresponding input shaft via gears; a reverse output gear fitted over one output shaft; a reverse synchronizer; a reverse shaft configured to rotate together with a input shaft and a reverse output gear; a motor power shaft; a first and a second motor gears fitted over the motor power shaft; the second motor gear configured to rotate together with a shift driven gear; and a motor synchronizer. A power transmission system including the transmission unit and a vehicle including the power transmission system are also provided.

A transmission for a vehicle may include a first input shaft continuously receiving torque from a power source and having a first input transfer gear thereon, a second input shaft selectively receiving torque from the power source through a clutch and having a second input transfer gear thereon, a coupling member allowing or restricting rotation of the first input transfer gear relative to the first input shaft, a first countershaft and a second countershaft each having an output transfer gear to be engaged with the first input transfer gear and the second input transfer gear, and coupling devices selectively coupling the output transfer gears to corresponding countershafts and allowing torque from the power source to be transmitted to a desired shift gear by coupling output transfer gears connected to the desired shift gear in the output transfer gears to a corresponding countershaft in advance or after synchronization in shifting.

An electromechanical power-split system and a method of operating thereof is provided, with a mechanical drive branch including an internal combustion engine (3), and with an electric drive branch including a first motor-generator block (59) including a first motor-generator (1) and a second motor-generator block (60) including a second motor-generator (2), the first motor-generator (1) is connectable to the internal combustion engine (3) and to the second motor-generator (2). The system includes a planetary gearset (4) with dual planet gears (46) and four input/output members for altering the flow ratio of the mechanical and electric drive branch . Each dual planet gear (46) is connected to the four input/output members, which are a first pair of input/output members formed by a first sun gear (41) and a ring gear (44), and a second pair of input/output members formed by a second sun gear (143) and a planet carrier (45).

A power shift transmission includes a plurality of shafts, a plurality of gears, a plurality of clutches, a plurality of forward modes, and a plurality of alternate forward modes. Each forward mode has a distinct transmission ratio, and each alternate forward mode has a transmission ratio similar to one of the plurality of forward modes.

A hybrid transmission system with a multi-speed gearbox. The multi-speed gearbox is configured to rotationally couple a prime mover and an electric machine to different gear ratios during a hybrid drive mode. The multi-speed gearbox includes an electric drive interface gear positioned coaxial to a first primary shaft and a second primary shaft and idly mounted, free to spin, to the second primary shaft and an output shaft that includes an output shaft gear which is fixedly coupled thereto meshes with a gear on a secondary shaft.