A control system for a vehicle transmission is provided. The control system includes an electronic control unit. The electronic control unit is configured to, when control for engaging the at least one engaging device that switches power transmission to power transmission via a first power transmission mechanism and control for increasing hydraulic pressure that is applied to a continuously variable transmission are required, control the continuously variable transmission and the at least one engaging device so as to start control for engaging the at least one engaging device first and, after a lapse of a predetermined time from the start of control for engaging the at least one engaging device, start control for increasing hydraulic pressure that is applied to the continuously variable transmission.

A hydraulic control system for a transmission is provided with a power source, two drive wheels, a power transmission device, a hydraulic pump, a main valve, and a controller. The power transmission device is configured to be set to a plurality of speed stages. The main valve is disposed between the hydraulic pump and the power transmission device and adjusts the main pressure of hydraulic fluid supplied from the hydraulic pump to the power transmission device. The controller controls the main valve. The controller sets the main pressure to a pressure value derived by correcting a clutch holding pressure of the set speed stage based on a load applied to each of the drive wheels.

A method of operating an agricultural vehicle including a range gearbox, an independent PTO system driven from an auxiliary drive shaft and a ground speed PTO system driven from an output shaft of the range gearbox. The method includes transferring torque from the auxiliary drive shaft to the output shaft of the range gear box via the independent PTO system and the ground speed PTO system while drive to the range gearbox is interrupted during a change in the range gear.

A hybridised drivetrain for a motor vehicle. A transmission assembly of the vehicle has at least one first planetary gear set. A first element of the first planetary gear set is a ring gear. A second element of the first planetary gear set can be connected to an electric machine of the vehicle with a clutch and can be secured against a housing. The second element is a sun gear. A third element of the first planetary gear set is connected to an output. The third element is a planet carrier. The ring gear can also be connected to the electric machine by means of a clutch. The clutch has an output disc carrier connected to the sun gear. The clutch has an output disc carrier connected to the ring gear. The input disc carrier and the output disc carrier can rotate relative to one another.

A hybridised drivetrain for a motor vehicle. A transmission assembly of the vehicle has at least one first planetary gear set. A first element of the first planetary gear set is a ring gear. A second element of the first planetary gear set can be connected to an electric machine of the vehicle with a clutch and can be secured against a housing. The second element is a sun gear. A third element of the first planetary gear set is connected to an output. The third element is a planet carrier. The ring gear can also be connected to the electric machine by means of a clutch. The clutch has an output disc carrier connected to the sun gear. The clutch has an output disc carrier connected to the ring gear. The input disc carrier and the output disc carrier can rotate relative to one another.

An automated manual transmission, comprising: a transmission control unit, a shift rod movable between a predetermined first position in which it engages a first gear combination of the transmission, a predetermined second position in which it engages a second gear combination of the transmission, and a predetermined neutral position in which it does not engage any gear, an actuator for moving the shift rod between the first position, the second position and the neutral position by applying a fluid pressure acting on the shift rod in response to signals from the transmission control unit, mechanical engagement means for maintaining the first and second positions of the shift rod without applying any fluid pressure by means of the actuator,
wherein the transmission is adapted to maintain the neutral position of the shift rod solely by applying fluid pressure acting on the shift rod.

An automated mechanical transmission for a vehicle includes a main gearbox assembly comprising a main shaft and being adapted to be shiftable between at least one engaged state and a neutral state; a split gearbox assembly comprising an input shaft and being adapted to be shiftable between a first engaged state, a second engaged state and a neutral state; a countershaft; a crawler gearbox assembly comprising a crawler gear engagement member which is adapted to selectively engage and disengage a crawler gear defining a torque path from the input shaft to the main gearbox assembly via the countershaft; a gearbox brake; and transmission control unit. The transmission is configured to be settable in an AMT neutral state defined by the main gearbox assembly being in the neutral state. When the transmission control unit obtains a request to engage the crawler gear from the AMT neutral state, the transmission control unit is configured to apply the gearbox brake so that a rotational speed of the countershaft is reduced to a first predetermined rotational speed which is higher than a zero rotational speed; and when the first predetermined rotational speed is reached, release the gearbox brake, set the split gearbox assembly to the neutral state and engage the crawler gear by the crawler gear engagement member.

An automated mechanical transmission for a vehicle includes a main gearbox assembly comprising a main shaft and being adapted to be shiftable between at least one engaged state and a neutral state; a split gearbox assembly comprising an input shaft and being adapted to be shiftable between a first engaged state, a second engaged state and a neutral state; a countershaft; a crawler gearbox assembly comprising a crawler gear engagement member which is adapted to selectively engage and disengage a crawler gear defining a torque path from the input shaft to the main gearbox assembly via the countershaft; a gearbox brake; and transmission control unit. The transmission is configured to be settable in an AMT neutral state defined by the main gearbox assembly being in the neutral state. When the transmission control unit obtains a request to engage the crawler gear from the AMT neutral state, the transmission control unit is configured to apply the gearbox brake so that a rotational speed of the countershaft is reduced to a first predetermined rotational speed which is higher than a zero rotational speed; and when the first predetermined rotational speed is reached, release the gearbox brake, set the split gearbox assembly to the neutral state and engage the crawler gear by the crawler gear engagement member.

A method of operating an agricultural vehicle including a range gearbox, an independent PTO system driven from an auxiliary drive shaft and a ground speed PTO system driven from an output shaft of the range gearbox. The method includes transferring torque from the auxiliary drive shaft to the output shaft of the range gear box via the independent PTO system and the ground speed PTO system while drive to the range gearbox is interrupted during a change in the range gear.

A speed-changing device (21) is provided with an input shaft (22), an output shaft (23), a planetary gear mechanism (29), a first variator (33), a second variator (34), and a controller (25). The planetary gear mechanism (29) is configured to include a carrier (29A) connected to the input shaft (22), a first sun gear (29B) connected to the first variator (33), and a second sun gear (29C) connected to the output shaft (23). The second variator (34) transmits power transmitted from the first variator (33) to the output shaft (23), or transmits power transmitted from the output shaft (23) to the first variator (33). The controller (25) changes the rotation speed of the first variator (33), thereby changing the rotation speed of the output shaft (23) in relation to the rotation speed of the input shaft (22).