In order to control the disengagement limit position of a movable dog relative to a fixed dog of a motor vehicle transmission, the following steps are implemented: acquiring position values of the movable dog; detecting an abutment position of the movable dog against the fixed dog for a predefined period; and calculating the limit position from the position value of the movable dog in abutment against the fixed dog.

A method for operating a vehicle drivetrain (1) includes decoupling, in the presence of a demand for realizing a sailing operating state of the vehicle drivetrain (1) during which a drive machine (2) is active and the power flow between the drive machine (2) and a drive output (3) is disconnected in a gearbox (4), the active drive machine (2) from the drive output (3) by opening of one of a plurality of shift elements (A to F) that is held in a closed operating state in order to realize the operating state present before the demand for decoupling of the active drive machine (2). The method also includes then actuating the plurality of shift elements (A to F) in a manner dependent on the present operating state profile of the vehicle drivetrain (1) and with the active drive machine (2) decoupled from the drive output (3).

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 dual clutch automatic transmission includes a one-way clutch provided in a driving force transmission path that establishes a first certain gear ratio in a first set of gear ratios. A driving transmission direction of the one-way clutch is set such that a rotation inputted from a wheel side to an output member in a predetermined rotational direction is transmitted to the input shaft. The predetermined rotational direction corresponds to a backward movement of a vehicle. If an off-gear operation cannot be performed for a transmission gear with interlock, the driving force of the driving source is input to the input shaft to enable the off-gear operation.

An electric driveline comprising an electric drive motor and a transmission, and a method of shifting gears therefor. The transmission comprises an output shaft, a synchronizer, preferably a hydraulically actuatable synchronizer, for selectively drivingly engaging the electric drive motor with the output shaft via either one of a first gear providing a first gear ratio γ.sub.1 between the electric drive motor and the output shaft, and a second gear providing a second gear ratio γ.sub.2 between the electric drive motor and the output shaft, and an electronic shift controller for controlling a gear shift from the first gear to the second gear. The electronic shift controller is configured to actuate the synchronizer to disengage the first gear and to engage the second gear, and to synchronize a motor speed of the electric drive motor with a target speed.

A gearbox comprising: a first shaft (2) and a second shaft (1), one of the first and second shafts being an input shaft (1) for receiving a drive torque and the other being an output shaft (2) for providing a drive torque; two intermediate shafts (6, 7) by means of which the first and second shafts (2, 1) can be coupled together, each intermediate shaft being arranged so that: (a) it can be coupled to the first shaft (2) via a respective first torque path at any of a plurality of gear ratios (1st-8th), or the respective first torque path can be disengaged; and (b) it can be coupled to the second shaft (1) via a respective second torque path, or the respective second torque path can be disengaged; and a differential torque device (50) coupled between the intermediate shafts (6, 7), the differential torque device (50) being capable of transmitting a differential torque between the intermediate shafts (6, 7).

A transmission system for a vehicle has a shift driving mechanism which operates, under control by a control unit, at the time of shifting the gear position, to disengage a transmission gear of a current gear position and a shifter from each other after engaging a transmission gear of a next gear position and a shifter with each other in a condition where a transmission clutch that transmits power to the transmission gear of the next gear position is in an engaged state. This ensures smoother and swifter shifting of gear position.

A control method is provided for controlling a declutching of a sliding gear of a vehicle gearbox having dogs. The sliding gear rotates with a shaft of the vehicle gearbox on which the sliding gear moves axially between a declutched position and an engaged position to transmit rotation to a vehicle wheel. The control method comprises applying a zero torque request to all power sources of the vehicle, applying a declutching instruction to the sliding gear, estimating a resistance torque on the dogs in absence of rapid declutching, calculating a residual torque on the dogs as a function of a calculated resistance torque and an anti-disengagement angle of the resistance torque on the dogs, cancelling the residual torque by application of two opposing cancellation torques on the sliding gear, and declutching the sliding gear.

A method for changing between a multiplicity of discrete transmission ratio stages in a motorcycle gearbox is provided. In response to a shift demand, during the torque-transmitting connection of a drive shaft of the drive machine to a gearbox input shaft, a gear-selection drum of the transmission is rotatable from a first shifting position to an intermediate position which is situated between the first and a second shifting position, before shifting to the second shift position. In the intermediate position, no drive torque can be transmitted from the gearbox input shaft to a gearbox output shaft. During the gear selection drum movement from the first shifting position and the intermediate position, the drum may be rotated to a rest position in which drive torque can be transmitted from the gearbox input shaft to a gearbox output shaft.

A method and system for operating a vehicle that includes a driveline disconnect clutch and a step-ratio transmission is described. In one example, the method includes shifting the step-ratio transmission to neutral and accelerating an engine to an expected input shaft speed of the step-ratio transmission via applying full output capacity of an electric machine to the engine.