A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.

A method for performing rotational speed synchronisation of a first transmission component having a first initial rotational speed with a second transmission component having a second initial rotational speed, so that they rotate with the same final rotational speed during a gear switch from an initial driving gear to a final driving gear in a stepped gear transmission for a hybrid electric or electric drive train having an electric traction motor. The method including calculating a total frictional work resulting from performing the total rotational speed synchronisation by means of a mechanical synchroniser of the stepped gear transmission only, and if the calculated total frictional work exceeds a maximal frictional work of the mechanical synchroniser, performing the rotational speed synchronisation by means of both the electric traction motor and the mechanical synchroniser.

A control device and a method for controlling a vehicle powertrain to overcome, or avoid, a cog-to-cog condition during gear shifting is provided. The method comprises, when an input shaft of the gearbox is rotating, controlling a synchromesh arrangement so as to induce a difference in rotational speed between a first gear wheel and a first coupling sleeve arranged to lock the first gear wheel to a main shaft of the gearbox by at least partly engaging the first gear wheel or a second gear wheel to the input shaft. Furthermore, a computer program, a computer-readable medium and a vehicle are provided.

Shifting device for shifting a transmission, having a first group of shift elements and a second group of shift elements, a selector shaft, which is arranged in such a way that it can be moved in translation along a longitudinal axis and rotated about the longitudinal axis, wherein it is possible, by moving the selector shaft into one of a plurality of possible translational positions, to select at least one shift element of the first group and at least one shift element of the second group and, by rotating the selector shaft, to actuate the selected shift elements. The at least one selected shift element of the first group can be actuated in phase or with an overlapping phase displacement or an offset phase displacement with respect to the at least one selected shift element of the second group.

An automatic transmission of the present invention is provided with: a plurality of rotating shafts; a plurality of gears; a plurality of synchronizing mechanisms including an output-side synchronizing mechanism; a lubricating oil storage part that stores a lubricating oil which is drawn upward by rotation of the gears; a shift position detection unit that detects which of a plurality of shift positions, including a neutral position, has been selected; and a control unit which, if the neutral position has been detected by the shift position detection unit, causes a synchronizing mechanism other than the output-side synchronizing mechanism to operate, and brings a clutch into a connected state after coupling a rotating shaft other than an output shaft and a gear other than an output-side gear.

An automatic transmission of the present invention is provided with: a plurality of rotating shafts; a plurality of gears; a plurality of synchronizing mechanisms including an output-side synchronizing mechanism; a lubricating oil storage part that stores a lubricating oil which is drawn upward by rotation of the gears; a shift position detection unit that detects which of a plurality of shift positions, including a neutral position, has been selected; and a control unit which, if the neutral position has been detected by the shift position detection unit, causes a synchronizing mechanism other than the output-side synchronizing mechanism to operate, and brings a clutch into a connected state after coupling a rotating shaft other than an output shaft and a gear other than an output-side gear.

A compact and fast-shifting two-speed transmission for an electric drive system, such as an electric vehicle, has two synchronized dog clutches. A sliding sleeve for engaging a first and second gear is actuatable using a single actuator. A substantially load-interruption-free shifting is realized via a friction engagement in the synchronization. A drive system having such a two-speed transmission is capable of achieving at least substantially load-interruption-free shifting.

Systems and methods are provided for simulating rev-matching in hybrid electric vehicles (HEVs), e.g., HEVs having a two motor hybrid system transmission. In particular, increased engine response is provided while downshifting during acceleration. The two-motor hybrid system transmission may include an electronic control unit that controls the speed of the engine to simulate gears, and increases the speed of the engine responsive to a driver using the gear selector to shift from one of the simulated gears to a lower one of the simulated gears, thereby providing the desired rev-matching experience.

A powertrain includes a transmission having an input shaft, an output shaft, and a plurality of clutches engageable in various combinations to establish varying power flow paths between the input and output shafts. A controller is programmed to, responsive to a shift of the transmission: reduce torque capacity of an off-going one of the clutches and increase torque capacity of an oncoming one of the clutches during a torque transfer phase of the shift, and, in response to an inertia phase of the shift, continue to command non-zero torque capacity to the off-going clutch such that the off-going clutch brakes the output shaft throughout an entire duration of the inertia phase.

A powertrain includes a transmission having an input shaft, an output shaft, and a plurality of clutches engageable in various combinations to establish varying power flow paths between the input and output shafts. A controller is programmed to, responsive to a shift of the transmission: reduce torque capacity of an off-going one of the clutches and increase torque capacity of an oncoming one of the clutches during a torque transfer phase of the shift, and, in response to an inertia phase of the shift, continue to command non-zero torque capacity to the off-going clutch such that the off-going clutch brakes the output shaft throughout an entire duration of the inertia phase.