A drivetrain system is disclosed for use with a machine having a work tool. The drivetrain system may have a transmission with a plurality of clutches. The drivetrain system may also have an input device movable by an operator to generate a first signal indicative of a desired selection of a park setting or one of a plurality of travel settings, a sensor configured to generate a second signal indicative of loading of the work tool, and a controller in communication with the input device, the sensor, and the transmission. The controller may be configured to anticipate completion of a loading cycle based the second signal, and to selectively cause at least a first of the plurality of clutches to engage in a combination that produces one of the plurality of travel settings based on the anticipated completion of the loading cycle, notwithstanding the desired selection from the input device being the park setting.

A drivetrain system is disclosed for use with a machine having a work tool. The drivetrain system may have a transmission with a plurality of clutches. The drivetrain system may also have an input device movable by an operator to generate a first signal indicative of a desired selection of a park setting or one of a plurality of travel settings, a sensor configured to generate a second signal indicative of loading of the work tool, and a controller in communication with the input device, the sensor, and the transmission. The controller may be configured to anticipate completion of a loading cycle based the second signal, and to selectively cause at least a first of the plurality of clutches to engage in a combination that produces one of the plurality of travel settings based on the anticipated completion of the loading cycle, notwithstanding the desired selection from the input device being the park setting.

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the dog clutch and the friction clutch. The controller starts the engagement of the dog clutch, after placing the dog clutch in a rotationally synchronized state by engaging the friction clutch and increasing an output rotation thereof, when there is a request to engage the dog clutch. In this clutch control device, the controller sets the engagement start timing of the friction clutch when a transition is made to the connected, four-wheel drive mode to an earlier timing compared to when a transition is made to the standby two-wheel drive mode, when there is a request to engage the dog clutch while in a state in which the disconnected, two-wheel drive mode is selected.

A clutch control device is provided for a four-wheel drive vehicle for transmitting drive force to the rear wheels. The clutch control device includes a dog clutch and a friction clutch, and a controller that controls the dog clutch and the friction clutch. The controller starts the engagement of the dog clutch, after placing the dog clutch in a rotationally synchronized state by engaging the friction clutch and increasing an output rotation thereof, when there is a request to engage the dog clutch. In this clutch control device, the controller sets the engagement start timing of the friction clutch when a transition is made to the connected, four-wheel drive mode to an earlier timing compared to when a transition is made to the standby two-wheel drive mode, when there is a request to engage the dog clutch while in a state in which the disconnected, two-wheel drive mode is selected.

A hydraulic system for a vehicle clutch assembly can include a pump and a purge valve for regulating hydraulic pressure supplied to the clutch. The hydraulic pressure at the pump can be set to a value higher than the operating pressure for the clutch. The purge valve can be configured to purge hydraulic pressure from the hydraulic system so that an optimum, controllable, and/or pre-determined operating pressure can be supplied to the clutch. The system can be configured to provide accurate control of the clutch(es), continuous cooling capacity to the hydraulic system components, lateral torque control when two separate hydraulic circuits are used, weight and cost reduction of the vehicle clutch, as well as other vehicle functions and characteristics.

A method of operating a dual-clutch transmission of a vehicle having partial transmissions with respective transmission input shafts. Two friction clutches can couple a corresponding input shaft of the partial transmissions to a drive shaft. Both partial transmissions drive a common output shaft. In a process for starting the motor vehicle, a gear in each of the two partial transmissions is engaged and, if the starting speed of the vehicle in a primary direction is lower than a limit value, the gears in the two partial transmissions are kept engaged. If, however, the starting speed is higher than the limit value, the gear for the travel in an opposite direction in the partial transmission, not involved in the starting process, is disengaged and a follow-up gear, for the gear in the partial transmission involved in the starting process, is engaged.

A method of operating a dual-clutch transmission of a vehicle having partial transmissions with respective transmission input shafts. Two friction clutches can couple a corresponding input shaft of the partial transmissions to a drive shaft. Both partial transmissions drive a common output shaft. In a process for starting the motor vehicle, a gear in each of the two partial transmissions is engaged and, if the starting speed of the vehicle in a primary direction is lower than a limit value, the gears in the two partial transmissions are kept engaged. If, however, the starting speed is higher than the limit value, the gear for the travel in an opposite direction in the partial transmission, not involved in the starting process, is disengaged and a follow-up gear, for the gear in the partial transmission involved in the starting process, is engaged.

A method of regulating a clutch assembly that has a set of clutch plates and a clutch piston with a fluid seal in an automatic transmission that includes a hydraulic circuit is disclosed. The method includes commanding the hydraulic circuit via the controller to apply a first hydraulic force to the clutch piston to displace the clutch piston relative to the set of clutch plates in order to affect a shift between speed-ratios in the transmission. The method also includes determining a drag force of the fluid seal. The method also includes determining a velocity of the displaced clutch piston that results from the drag force of the fluid seal acting counter to the displacement of the clutch piston. The method additionally includes regulating the clutch assembly to compensate for the determined drag force of the fluid seal acting counter to the displacement of the clutch piston.

A method of regulating a clutch assembly that has a set of clutch plates and a clutch piston with a fluid seal in an automatic transmission that includes a hydraulic circuit is disclosed. The method includes commanding the hydraulic circuit via the controller to apply a first hydraulic force to the clutch piston to displace the clutch piston relative to the set of clutch plates in order to affect a shift between speed-ratios in the transmission. The method also includes determining a drag force of the fluid seal. The method also includes determining a velocity of the displaced clutch piston that results from the drag force of the fluid seal acting counter to the displacement of the clutch piston. The method additionally includes regulating the clutch assembly to compensate for the determined drag force of the fluid seal acting counter to the displacement of the clutch piston.

A gearbox decoupling apparatus and method for powering an accessory system. The gearbox decoupling apparatus employs a worm gear mechanism having an input worm pinion engaged with a worm gear wheel. A threaded rod is engaged with the worm gear wheel. A decoupling adapter is connected to the threaded rod. Rotation of the input worm pinion imparts movement of the decoupling adapter between a first position and a second position. When the decoupling adapter is in the first position, the decoupling adapter is mechanically engaged with a power take-off gear and a power take-off adapter. When the decoupling adapter is in the second position, the decoupling adapter is mechanically engaged with the power take-off gear and disengaged from the power take-off adapter thus allowing an accessory system to be powered by an alternate power source other than a main power source that is permanently connected to the power take adapter.