The invention relates to the actuation of a converter lock-up clutch (44) of a hydrodynamic torque converter (4) in a vehicle drive-train by means of a safety function where, in addition to a driving strategy function, the safety function can actuate the converter lock-up clutch (44) by issuing a clutch actuation command. For this purpose, at least one rotation speed at the torque converter (4) is monitored. If the monitored rotation speed is below a rotation speed threshold, the safety function commands an actuation of the converter lock-up clutch (44) in its opening direction.

The invention relates to the actuation of a converter lock-up clutch (44) of a hydrodynamic torque converter (4) in a vehicle drive-train by means of a safety function where, in addition to a driving strategy function, the safety function can actuate the converter lock-up clutch (44) by issuing a clutch actuation command. For this purpose, at least one rotation speed at the torque converter (4) is monitored. If the monitored rotation speed is below a rotation speed threshold, the safety function commands an actuation of the converter lock-up clutch (44) in its opening direction.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. An integrated actuator housing includes a single external power access for the shift actuator. A controller interprets a shaft displacement angle, determines if the transmission is in an imminent zero or zero torque region, and performs a transmission operation in response to the transmission in the imminent zero or zero torque region.

Embodiments of this application provide a speed shifting apparatus, a control method thereof, a steering system, and a control method thereof, and relate to the field of mechanical transmission technologies. The speed shifting apparatus includes: an outer rotating wheel; an inner rotating wheel, where a rotation axis of the inner rotating wheel is parallel to and different from a rotation axis of the outer rotating wheel; and a plurality of meshing members, arranged along a circumferential direction of the inner rotating wheel or the outer rotating wheel. Either the outer rotating wheel or the inner rotating wheel is provided with a plurality of sliding grooves, and the plurality of sliding grooves are in a one-to-one correspondence with the plurality of meshing members.

Embodiments of this application provide a speed shifting apparatus, a control method thereof, a steering system, and a control method thereof, and relate to the field of mechanical transmission technologies. The speed shifting apparatus includes: an outer rotating wheel; an inner rotating wheel, where a rotation axis of the inner rotating wheel is parallel to and different from a rotation axis of the outer rotating wheel; and a plurality of meshing members, arranged along a circumferential direction of the inner rotating wheel or the outer rotating wheel. Either the outer rotating wheel or the inner rotating wheel is provided with a plurality of sliding grooves, and the plurality of sliding grooves are in a one-to-one correspondence with the plurality of meshing members.

A method of controlling gear selection in a vehicle transmission comprises detecting a change in a direction control signal (DCS) from a neutral signal state. If the current TOS is less than or equal to a predetermined neutral shift threshold TOS, the transmission selects one of a plurality of first direction gears if the DCS was changed to a first direction signal state or one of a plurality of second direction gears if the DCS was changed to a second direction signal state. If the current TOS is greater than the predetermined neutral shift threshold TOS, the transmission selects one of the plurality of first direction gears if a machine motion direction parameter indicates that the vehicle is moving in the first direction or one of the plurality of second direction gears if the machine motion direction parameter indicates that the vehicle is moving in the second direction.

A method of controlling gear selection in a vehicle transmission comprises detecting a change in a direction control signal (DCS) from a neutral signal state. If the current TOS is less than or equal to a predetermined neutral shift threshold TOS, the transmission selects one of a plurality of first direction gears if the DCS was changed to a first direction signal state or one of a plurality of second direction gears if the DCS was changed to a second direction signal state. If the current TOS is greater than the predetermined neutral shift threshold TOS, the transmission selects one of the plurality of first direction gears if a machine motion direction parameter indicates that the vehicle is moving in the first direction or one of the plurality of second direction gears if the machine motion direction parameter indicates that the vehicle is moving in the second direction.

Disclosed is a method for operating a multi-speed vehicle transmission having a plurality of shift elements (A, B, C, D, E) for engaging the gears of the vehicle transmission. The method includes decoupling between an input (AN) and an output (AB) of the vehicle transmission in a neutral gear, and coupling the input (AN) and the output (AB) of the vehicle transmission in a drive gear for propelling the vehicle by closing at least one shift element (B). At least one transmission state is determined when the neutral gear is engaged, where a shift element (D) for a reverse gear of the vehicle transmission is closed at least partially if the transmission is in a state with increased drag losses when the neutral gear is engaged.

Disclosed is a method for operating a multi-speed vehicle transmission having a plurality of shift elements (A, B, C, D, E) for engaging the gears of the vehicle transmission. The method includes decoupling between an input (AN) and an output (AB) of the vehicle transmission in a neutral gear, and coupling the input (AN) and the output (AB) of the vehicle transmission in a drive gear for propelling the vehicle by closing at least one shift element (B). At least one transmission state is determined when the neutral gear is engaged, where a shift element (D) for a reverse gear of the vehicle transmission is closed at least partially if the transmission is in a state with increased drag losses when the neutral gear is engaged.

Disclosed is a transportation unit comprising: a plurality of roadway wheels including wheel, a plurality of continuously variable transmissions (CVTs) including a first CVT and a second CVT, the plurality of CVTs receiving rotational input from the wheel, and a generator that is rotationally driven by rotational output from the plurality of CVTs, and wherein each of the plurality of CVTs is engaged over one of a corresponding plurality of discrete wheel rotational speeds.