F16H61/702

Electronic control of a transmission

A recreational vehicle is provided including a power source, such as an engine or an electric motor, and a transmission having a variable gear ratio. A sub-transmission coupled to an output of the transmission includes a plurality of selectable gear configurations including park gear and at least one of a forward gear, a neutral gear and a reverse gear. An electronic controller is operative to electronically control the gear configuration of the sub-transmission in response to a set of conditions.

METHOD AND CONTROL DEVICE FOR OPERATING A DRIVETRAIN
20210245761 · 2021-08-12 ·

A method of operating a motor vehicle drive-train having a drive aggregate, a group transmission and a drive output. The aggregate can couple an input shaft of the transmission which includes main, splitter and range groups. To carry out a shift, a target gear and target rotational speed of the aggregate are calculated for the shift to be carried out. After the initiation of the shift a load reduction is first carried out, then a group of the transmission is disengaged in order to shift the transmission to neutral, after which a group of the transmission is synchronized and to shift out of neutral, the synchronized group is engaged, and then the load is again built up. Initiation of the shift, after calculating the target gear and the target rotational speed, occurs at a point in time when complete performance of a shift is not yet possible.

CONTROL DEVICE FOR VEHICLE POWER TRANSMISSION DEVICE
20210284170 · 2021-09-16 · ·

An electronic control unit engages two of friction engagement elements provided in an automatic transmission in a neutral range. The electronic control unit disengages one of the two friction engagement elements engaged in the neutral range at the time of starting gear stage switching of an auxiliary transmission from a low-speed gear stage to a high-speed gear stage in the neutral range, and re-engages the friction engagement element that has been disengaged when determining that the gear stage switching has been completed.

Apparatus and method for controlling continuously variable transmission

A vehicle has an engine (1) as a driving source. Output rotation of the engine (1) is transmitted to driving wheels (7) through a torque converter (2) equipped with a lock-up clutch, a first gear train (3), a transmission (4) formed by combination of a variator (20) and an auxiliary transmission (30), a second gear train (5) and a final speed reduction device (6). The second gear train (5) is provided with a parking mechanism (8) that mechanically locks an output shaft of the transmission (4) so that the output shaft of the transmission (4) cannot rotate during parking of the vehicle. A shift speed when down-shift is performed by the variator (20) during a torque-down request to the engine (1) is set to be slower than a shift speed when down-shift is performed by the variator (20) during a non-torque-down request.

SHIFT CONTROL APPARATUS FOR VEHICLE AUTOMATIC TRANSMISSION

A shift control apparatus for a vehicle automatic transmission to be provided in a vehicle that includes a hydraulic transmission device having a lockup clutch, an engine, an input shaft connected to the engine through the hydraulic transmission device, and drive wheels. The shift control apparatus includes a shift-down control portion configured, when a shift-down operation is executed to establish a first gear position by releasing a second engagement device, during running of the vehicle in a driven state with a second gear position being established with engagement of the second engagement device, to increase a torque of the engine so as to increase an input rotational speed as a rotational speed of the input shaft through the lockup clutch that is placed in an engaged state, and to release the lockup clutch before the input rotational speed reaches a synchronous speed of the first gear position.

Control device for continuously variable transmission and control method for continuously variable transmission

A controller constitutes a control device for continuously variable transmission for executing a feedback control of a transmission so that an actual speed ratio reaches a target speed ratio. The controller includes a first phase lead compensator and a second phase lead compensator configured to perform phase lead compensation of a feedback primary command pressure, and a peak value frequency determination unit configured to change a peak value frequency according to a speed ratio.

CONTROL DEVICE FOR VEHICULAR TRANSMISSION

When a rotation speed difference between rotary members of a mode switching clutch is equal to or less than a predetermined value during travel in a belt travel mode, there is a likelihood that the mode switching clutch would be secured to a lock mode in which power operating in two directions is transmitted. At this time, since switching to a gear travel mode is prohibited, it is possible to curb occurrence of a shock when power is simultaneously transmitted via a first power transmission path and a second power transmission path in a transition period of switching to the gear travel mode.

Method and system of learning pressure applied to countershaft brake
11009123 · 2021-05-18 · ·

A method and a system of learning a pressure applied to a brake of a countershaft may include determining, when a shift condition is satisfied, whether a shifting to be performed is a power off upshift; releasing a clutch mounted between a power source and the transmission when the shifting to be performed is the power off upshift; detecting a contact duration until a speed of an input shaft of the transmission is lowered by a predetermined speed by applying a target pressure stored in a memory to the brake of the countershaft when the release of the clutch is completed; comparing the contact duration with a predetermined duration; correcting, when the contact duration is greater than the predetermined duration, the target pressure according to a difference between the contact duration and the predetermined duration; and storing and updating the corrected target pressure in the memory to apply a subsequent power on upshift.

APPARATUS AND METHOD FOR CONTROLLING CONTINUOUSLY VARIABLE TRANSMISSION

A vehicle has an engine (1) as a driving source. Output rotation of the engine (1) is transmitted to driving wheels (7) through a torque converter (2) equipped with a lock-up clutch, a first gear train (3), a transmission (4) formed by combination of a variator (20) and an auxiliary transmission (30), a second gear train (5) and a final speed reduction device (6). The second gear train (5) is provided with a parking mechanism (8) that mechanically locks an output shaft of the transmission (4) so that the output shaft of the transmission (4) cannot rotate during parking of the vehicle. A shift speed when down-shift is performed by the variator (20) during a torque-down request to the engine (1) is set to be slower than a shift speed when down-shift is performed by the variator (20) during a non-torque-down request.

Transmission arrangement, travel drive having the transmission arrangement and method for controlling the transmission arrangement
10907713 · 2021-02-02 · ·

A transmission arrangement for a travel drive, in particular a mobile machine, includes a first hydraulic machine configured to be coupled to a drive machine, and a second hydraulic machine having an adjustable second expulsion volume, the second hydraulic machine configured to be connected fluidically to the first hydraulic machine via a first working line and a second working line of the transmission arrangement. The second hydraulic machine configured to be coupled or is coupled to a manual transmission of the transmission arrangement. The manual transmission has at least two transmission stages, and coupling of the second hydraulic machine to the manual transmission has the result that a torque can be transmitted. The transmission arrangement further includes a control apparatus configured to reduce to zero or to nearly zero the second expulsion volume at least during a changeover from one transmission stage to another transmission stage of the manual transmission.