An automatic transmission that includes a speed change mechanism including a gear mechanism that can attain a plurality of shift speeds, and a plurality of friction engagement elements that are selectively engaged to attain each shift speed in the gear mechanism; a hydraulic control device that can regulate engagement pressures to be supplied to hydraulic servos of the plurality of friction engagement elements and that can supply lubricating oil that lubricates the speed change mechanism; and a control unit that sends a command about the engagement pressures to the hydraulic control device to control engagement states of the plurality of friction engagement elements.

Methods and systems for a hydromechanical transmission are provided. In one example, the method includes responsive to rotation of a portion of a mechanical assembly induced by cranking of an engine, blocking an output shaft of the hydromechanical transmission via joint engagement of a forward drive clutch and a reverse drive clutch. The method further includes pressurizing a hydrostatic assembly while the forward drive clutch and the reverse drive clutch remain jointly engaged, where the mechanical assembly is coupled in parallel with the hydrostatic assembly.

Various methods and systems are provided for a shift assembly for a vehicle transmission. In one example, a shift assembly for a transmission includes a first barrel cam including a first cam track; a second barrel cam arranged coaxially with the first barrel cam and including a second cam track; a first motor configured to drive the first barrel cam independent of the second barrel cam; and a second motor configured to drive the second barrel cam independent of the first barrel cam.

A transmission assembly includes a common ring gear assembly, a first sun gear, a first planet carrier, a second sun gear and a second planet carrier. A set of planet gears of each one of the first and second planet carriers meshing with the common ring gear assembly. The set of planet gears of the first planet carrier meshing with the first sun gear and the set of planet gears of the second planet carrier meshing with the second sun gear. The transmission assembly further includes a transmission housing.

The second sun gear is adapted to be connected to a transmission input shaft;

the common ring gear assembly is adapted to be connected to a transmission output shaft, and

the second planet carrier and the first sun gear are operatively connected to each other.

A gear shifting apparatus in a new energy vehicle includes a primary power transmission unit, a secondary power transmission unit, an intermediate shaft, an intermediate shaft gear, a first clutch unit, a second clutch unit, and a third clutch unit. The intermediate shaft gear is fixedly sleeved on the intermediate shaft, and the first clutch unit is disposed between the intermediate shaft and the primary power transmission unit. The second clutch unit is disposed between the intermediate shaft and the secondary power transmission unit. The third clutch unit is disposed between the primary power transmission unit and the intermediate shaft gear.

A dual clutch transmission for a motor vehicle, with a first sub-transmission, with a second sub-transmission, with a first clutch associated with the first sub-transmission, and with a second clutch associated with the second sub-transmission. The dual clutch transmission is designed to be shifted into a parking lock state, in which two gears of one of the sub-transmissions are simultaneously engaged, and in the lock state, the two gears of the one first sub-transmission are simultaneously engaged. A first gear wheel of a first of the gears, which is designed as loose wheel and rotatably arranged on a first shaft of the dual clutch transmission, is connected in a torque-proof manner to the first shaft, by a first switching element.

A method for operating a dual clutch transmission of a motor vehicle having a first partial transmission, a second partial transmission, a first clutch assigned to the first partial transmission and a second clutch assigned to the second partial transmission, in which the dual clutch transmission is in a parking lock state in which two gears of one of the partial transmissions are engaged simultaneously. The following steps are carried out to exit the parking lock state: Introducing a torque caused by a drive element of the motor vehicle via the clutch associated with the one partial transmission into the one and/or other partial transmission while the gears of the partial transmission are engaged; and disengaging at least one of the gears of the one partial transmission engaged simultaneously in step a).

A method for operating a dual-clutch transmission having a first partial transmission, a second partial transmission, a first clutch assigned to the first partial transmission, and a second clutch assigned to the second partial transmission, in which the dual-clutch transmission is shifted into a parking lock state. The dual-clutch transmission is shifted into the parking lock state by the following steps: while a first gear of one of the partial transmissions is engaged: carrying out an engagement process provided for engaging a second gear of the one partial transmission; determining that the second gear is not engaged despite the engagement process being carried out; selecting a third gear of the dual-clutch transmission different from the first gear and from the second gear; and engaging the selected third gear such that in the park lock condition, the first gear and the third gear are at least temporarily engaged simultaneously.

A commercial vehicle with at least one driven axle, at least one service brake, at least one propulsion engine, and wheels characterized in that the parking brake function of the vehicle is solved by a bistable locking means acting on both wheels. At least one multi-speed gearbox is provided to concurrently activate a first gear stage and a second gear stage having different ratios.

Methods and systems for a hydromechanical transmission in a vehicle are provided herein. In one example, the transmission system includes a hydrostatic assembly with a hydraulic pump in fluidic communication with a hydraulic motor. The transmission system further includes a controller configured to selectively transition between a torque control mode and a speed control mode of the hydrostatic assembly while the vehicle is on a slope.