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.

A power system includes an engine; a sensor to determine an engine speed; and a transmission. The transmission includes an input element configured to receive the power from the engine as input torque; an output element configured to provide at least a portion the power from the engine as output torque; and a clutch arrangement to transform the input torque into output torque. The clutch arrangement includes at least one clutch selectively positionable between a fully engaged state, a partially engaged state in which a portion of the input torque is transformed into the output torque, and a fully disengaged state. A controller is coupled to the at least one clutch and configured to generate clutch commands based at least in part on the engine speed to position the at least one clutch into the fully engaged state, the partially engaged state, or the fully disengaged state.

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 determining reference values of a sensor corresponding to a disengaged operating condition or to an engaged operating condition of a hydraulically actuatable, form-locking shift element (A, F), where at least one operating parameter of the form-locking shift element (A, F) is detected with the sensor during a disengagement and during an engagement of the form-locking shift element (A, F). The method may include subdividing an operating range of the shift form-locking element (A, F) into temperature and pressure classes. The method may further include determining a deviation between a current reference value for a temperature and pressure class of the temperature and pressure classes and an adapted reference value previously determined for the temperature and pressure class. Additionally, the method may include increasing or decreasing the adapted reference value by a predefined increment based on the deviation.

A transmission includes an input shaft and an output shaft, the input shaft selectively accepting a torque input from a prime mover, and the output shaft selectively providing torque output to a driveline. A controller determines a shaft displacement angle representing an angle value of rotational displacement difference between at least two shafts of the transmission, and performs a transmission operation responsive to the shaft displacement angle.

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 of a gear transmission-equipped vehicle includes a power controller that starts power reduction control when it is determined that a start condition is satisfied, the power reduction control being control of reducing power transmitted from a driving source to a gear transmission. The start condition includes: a condition that a detection value of a gear position sensor that detects a current gear position of the gear transmission falls within a transition region between engagement regions corresponding to respective gear positions; and a condition that a speed difference obtained by subtracting a rotational speed of an output shaft of the gear transmission from a rotational speed of an input shaft of the gear transmission is a threshold or more.

A method of shifting a vehicle transmission including a first clutching device and a second clutching device is described. At least a portion of the first clutching device is coupled with or configured to be coupled with at least a portion of the second clutching device. The method may include the steps of engaging the second clutching device, where engaging the second clutching device includes controlling a state of the second clutching device by changing a state of the first clutching device. A transmission controller and a vehicle driveline are also described.

A hydraulic pressure calculation apparatus is applied to a gear shifting system including a transmission configured to switch between a connected state and a disconnected state of a friction engagement element depending on a hydraulic pressure supplied from a hydraulic circuit, and a hydraulic controller configured to control the hydraulic circuit. The hydraulic pressure calculation apparatus includes a memory and a processor. The memory stores pieces of mapping data of a plurality of phases obtained by dividing a period from a start to an end of switching between the connected state and the disconnected state of the friction engagement element. Each piece of the mapping data defines a mapping. The processor is configured to output, as an output variable, an estimated hydraulic pressure variable indicating an estimated value of an actual hydraulic pressure supplied from the hydraulic circuit to the friction engagement element.

A control device of a gear transmission-equipped vehicle includes a power controller that starts power reduction control when it is determined that a start condition is satisfied, the power reduction control being control of reducing power transmitted from a driving source to a gear transmission. The start condition includes: a condition that a detection value of a gear position sensor that detects a current gear position of the gear transmission falls within a transition region between engagement regions corresponding to respective gear positions; and a condition that a speed difference obtained by subtracting a rotational speed of an output shaft of the gear transmission from a rotational speed of an input shaft of the gear transmission is a threshold or more.