The disclosure relates to a method for operating a drivetrain for a work machine, wherein a first electric motor drives a work drive of the work machine via a first transmission arrangement, wherein a second electric motor drives a traction drive of the work machine via a second transmission arrangement, and wherein, during a shift process of the second transmission arrangement from a relatively low gear ratio stage to a relatively high gear ratio stage, the rotational speed of the second electric motor is reduced. The method according to the disclosure is distinguished by the fact that, during the shift process, a driving connection is produced between the first electric motor and the second transmission arrangement by a first clutch, such that, during the shift process, the first electric motor drives the traction drive. The disclosure furthermore relates to a corresponding drivetrain and to a work machine.

The disclosure relates to a method for operating a drive train for a working machine, in which a working drive of the working machine is driven by a first electric motor via a first gear arrangement, a travel drive of the working machine is driven by a second electric motor via a second gear arrangement and, in a shifting procedure of the second gear arrangement, the rotational speed of the second electric motor is synchronised and the temperature of said second electric motor is recorded. In the disclosed method, the rotational speed is synchronised by supplying current to the second electric motor, and in the event of a threshold temperature being exceeded, at least one measure is carried out to relieve the thermal load of the second electric motor. The disclosure further relates to a corresponding drive train and to a working machine.

A hybrid drive sub-assembly for a vehicle has primary gear wheels, secondary gear wheels that are able to be coupled to a secondary shaft, and an intermediate shaft to which intermediate gear wheels are secured for rotation therewith. The primary gear wheel(s) and the secondary gear wheels each meshing permanently with a corresponding gear wheel from among the intermediate gear wheels. This hybrid sub-assembly is equipped with a motorized module having a reversible electric machine, an interface for connecting to the intermediate shaft, a speed reducer, a torsional oscillation damping device and a coupling mechanism that is able to couple and uncouple the reversible electric machine and the intermediate shaft.

A motor vehicle has at least two drive motors, at least one drive motor being an electric machine; a high-voltage accumulator; and an automatic gearbox, having at least one fixed transmission ratio and at least one power-split transmission ratio for transmission regulation starting from the at least one fixed transmission ratio. The motor vehicle further includes an electronic control unit, which is designed such that, when a gear change command is present, the shifting element to be opened of the fixed transmission ratio to be disengaged is unloaded in a torque-controlled manner by at least two of the drive motors. For the shifting element to be opened, the torque load is calculated and observed. The torque load is observed with the objective of bringing about a load change by way of a zero crossing in order to produce a no-load state at the shifting element. For producing the no-load state of the shifting element to be opened, a first drive motor and a second drive motor are controlled in a power split manner such that they, in terms of rotational speeds, maintain the transmission of the previously engaged fixed transmission ratio, and, in terms of torque, put the shifting element to be opened in an at least nearly no-load state, and a load change is brought about at the shifting element to be opened by a differential rotational speed, opposite the calculated torque load at the shifting element to be opened, being specified at the shifting element.

Provided is a control device performing upshifting engagement control where engagement pressure of a second engagement device is gradually increased, and disengagement control where a disengagement force to disengage a first engagement device acts on a meshing portion of the first engagement device. The control device gradually increases engagement pressure of the second engagement device toward target engagement pressure at which transmission torque capacity of the second engagement device reaches a magnitude determined based on input torque from a drive power source to an input member, and changes engagement pressure of the second engagement device set at or after a time when the engagement pressure of the second engagement device reaches set engagement pressure lower than the target engagement pressure, smaller than a change rate of the engagement pressure of the second engagement device set before reaching the set pressure, and thereafter starts the disengagement control.

A hybrid power system and an operating method, a torque distribution method and a gear shifting control method of the same. A transmission of the hybrid power system employs two independent input shafts and two motors which are in transmission connection with the two input shafts respectively, and an engine is in transmission connection with one of the two motors via a clutch. In this way, in one aspect, a torque compensation can be constantly carried out in a gear shift process of the hybrid power system, thereby avoiding a torque interruption phenomenon for the hybrid power system in the gear shift process; in the other aspect, the hybrid power system can enable a serial mode in which one motor is driven by the engine to charge a battery while the other motor is driven to transmit torque to the transmission for driving.

Methods and system are described for changing a gear ratio of an axle gearbox that does not include friction clutches and that may or may not include synchronizers. The axle gearbox may receive propulsive force via an electric machine. The methods and systems permit the axle gearbox to be shifted from a high gear range to a low gear range while a vehicle that includes the axle gearbox is moving.

A method of controlling a hybrid power train may include: driving a first input shaft connected to a second motor-generator by the second motor-generator to synchronize a speed of a driven gear of a target gear position with a speed of an output shaft; moving a sleeve to directly connect the second input shaft, the output shaft, and the driven gear of the target gear position; decreasing torque of the first motor-generator and increasing torque of the second motor-generator to converge torque transferred from the second motor-generator to the output shaft, to torque of the output shaft; moving the sleeve to release the second input shaft and maintain only the output shaft and the driven gear; and increasing torque of an engine and decreasing the torque of the second motor-generator to converge torque transferred from the engine to the output shaft, to the torque of the output shaft.

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 control system for a power transmission unit configured to shift an operating mode smoothly by manipulating engagement devices, and to simplify a structure of the power transmission unit. The control system is configured to reduce a speed difference between an axially stationary engagement element and a reciprocatable engagement element of a second engagement device when shifting from a first continuously variable mode to a second continuously variable mode by engaging the second engagement device. After the second engagement device has been engaged completely, a first engagement device is disengaged.