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.

A method of shifting a vehicle transmission including a first clutching device and a second clutching device is described. At least a portion of the first clutching device is coupled with or configured to be coupled with at least a portion of the second clutching device. The method may include the steps of engaging the second clutching device, where engaging the second clutching device includes controlling a state of the second clutching device by changing a state of the first clutching device. A transmission controller and a vehicle driveline are also described.

An engagement operation of a dog clutch is carried out while an engagement operation of a second clutch is being carried out, that is, during a situation that an uplock is hard to occur because of a phase shift generated between meshing counterpart members of the dog clutch. Thus, the dog clutch is easily engaged, and it is possible to facilitate preparation for transmission of power through a first power transmission path. If the dog clutch is not engaged, the second clutch is engaged and a second power transmission path is established, so it is possible to start moving a vehicle by transmitting power through the second power transmission path. Thus, when the dog clutch is in a non-engaged state at the time of an N-to-D shift during a stop of the vehicle, it is possible to ensure the startability of the vehicle.

A drive-train for a vehicle with at least one electric drive, which can be coupled via a driveshaft (2) to at least a first transmission ratio stage (i1) and a second transmission ratio stage (i2). At least one shifting mechanism is provided for engaging the transmission ratio stages (i1, i2). To carry out powershifts, the shifting mechanism includes at least one interlocking shifting element (5) and at least one frictional shifting element (6, 6A). Each of the transmission ratio stages (i1, i2) can be engaged by the interlocking shifting element (5) and at least one of the transmission ratio stages (i2) can be engaged both by the interlocking shifting element (5) and by the frictional shifting element (6). Methods for carrying out a powershift, between a frictional shifting element (6, 6A) and an interlocking shifting element (5) in the drive-train, are also disclosed.

A gear shift control system controls an actuator so that a pushing force will be a constant gearing-phase pushing force, during a gearing phase. The gear shift control system performs control on the basis of the number of rotation of the engine in the gearing phase, which is measured at the start of the gearing phase, so that the constant gearing-phase pushing force will increase as a number of rotation of the engine in the gearing phase increases. Thus, the hitting sound due to collision between the sleeve and the shift gear in shifting gears is reduced.

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.

A method for operating a dual-clutch transmission of a motor vehicle, wherein a first clutch is operated closed or engaged and in this way a first transmission branch is driven, in which a current actual gear is engaged, and in a pre-selection phase for a gear changed to a desired gear in a second transmission branch, the desired gear is engaged, and in a second clutch, a clutch hydraulic system is filled and, in this way, the second clutch is closed. The gear change shall be made faster. The filling of the clutch hydraulic system is begun already during the pre-selection phase, and, in this case, the clutch hydraulic system is filled in the pre-selection phase but at most up to reaching a touch point of the second clutch.

A transmission is subject to gear shift management that provides for shifting gears in a controlled manner in order to provide for a simplification of part and reduction in system complexity. In particular, a range synchronizer component can be replaced with a simplified range jaw clutch, without incurring a requirement for an installation of other components such as a motor generator or starter-generator.

A system, method and apparatus are disclosed for a clutch assembly for an automated manual transmission. The clutch assembly includes a dual power path. One power path connects a prime mover to the automated manual transmission via a wet clutch, and a second power path connects one of the prime mover and the automated manual transmission to a grounded connection for synchronizing the speed thereof for a gear change.

A method to control the execution of a shift to a lower gear while an accelerator pedal is released in a drivetrain provided with a dual-clutch, servo-assisted transmission; the control method comprises the following steps: opening, in a first instant, an outgoing clutch; closing, in the first instant, an incoming clutch; completing the opening of the outgoing clutch and the closing of the incoming clutch in a second instant; synchronizing, between the second instant and a third instant, a rotation speed of the internal combustion engine with a rotation speed of the incoming clutch; and controlling the incoming clutch between the second instant and the third instant so as to have the incoming clutch temporarily transmit a greater torque than the torque that the clutch is going to transmit immediately after the shift to a lower gear and than the torque that the outgoing clutch transmitted immediately before the shift to a lower gear.