A hydro-mechanical transmission device with a dual-clutch transmission includes an input mechanism, a pump-controlled motor mechanism, an odd-numbered gear transmission mechanism, an even-numbered gear transmission mechanism, an output mechanism, and a jackshaft. The input mechanism is connected to the odd-numbered gear transmission mechanism and the even-numbered gear transmission mechanism that are connected in parallel, and is connected to an input end of the pump-controlled motor mechanism. An output end of the pump-controlled motor mechanism is connected, through the jackshaft, to the odd-numbered gear transmission mechanism and the even-numbered gear transmission mechanism that are connected in parallel, and is connected to the output mechanism. Switching among hydraulic transmission, hydro-mechanical transmission, and mechanical transmission modes between the input mechanism and the output mechanism is implemented by controlling combination and engagement/disengagement of clutches and a brake.

A diagnosis device determines diagnoses one of primary and secondary board temperature sensors as abnormal, in response to a condition that a state in which a primary temperature sensor value and a secondary temperature sensor value deviate from each other by a predetermined value or more continues for a predetermined duration or more; performs torque limitation to limit a torque inputted from an engine to an automatic transmission, during driving in a predetermined travel section based on a predetermined condition, after the one of the primary and secondary board temperature sensors is diagnosed as abnormal; and performs transmission shift restriction to restrict shifting of the automatic transmission along with the torque limitation, in response to a condition that the one of the primary and secondary board temperature sensors continues to be diagnosed as still abnormal after the driving in the predetermined travel section is completed.

The lock-up control unit is configured to: in a case where the normal mode is selected, disengage the lock-up clutch when a vehicle speed decreases and reaches a first vehicle speed while the vehicle is traveling in a state where the lock-up clutch is engaged, in a case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a second vehicle speed in a brake operation OFF state while the vehicle is traveling in the state where the lock-up clutch is engaged, in the case where the eco mode is selected, disengage the lock-up clutch when the vehicle speed decreases and reaches a third vehicle speed in a brake operation ON state while the vehicle is traveling in the state where the lock-up clutch is engaged, and set the third vehicle speed to a vehicle speed lower than the first vehicle speed, and set the second vehicle speed to a vehicle speed higher than the first vehicle speed.

An electro-hydraulic control system for a multispeed transmission having a plurality of torque-transmitting mechanisms includes a controller for operably controlling the transmission, a fluid source for supplying hydraulic fluid, and a plurality of torque-transmitting mechanisms being operably selected between an applied and an unapplied state to achieve a plurality of ranges including at least one reverse, a neutral, and a plurality of forward ranges. The system includes a plurality of trim systems having pressure control solenoids and trim valves. The system may also include one or more shift valves disposed in fluid communication with the fluid source and being capable of moving between stroked and de-stroked positions. In any given range, only two of the plurality of torque-transmitting mechanisms may be applied. Moreover, three of the plurality of pressure control solenoids are normally high solenoids, and the remaining solenoids are normally low solenoids.

A gearbox (10) is provided having: a gearbox case (12), a first shaft (14) for receiving torque, a second shaft (16) for transferring torque inside the gearbox case (12), and a third shaft (18) for delivering torque. The gearbox further has three or more first gear assemblies (20) located inside the gearbox case (12), wherein each first gear assembly (20) comprises a first gear wheel (22) centered on the first shaft (14), a second gear wheel (24) centered on the second shaft (16), and a wet clutch (26) configured for operationally connecting the first shaft (14) and the second shaft (16). The gearbox also has three or more second gear assemblies (30) located inside the gearbox case (12), wherein each second gear assembly (30) comprises a third gearwheel (32) centered on the second shaft (16), a fourth gear wheel (34) centered on the third shaft (18), and a wet clutch (36) configured for operationally connecting the second shaft (16) and the third shaft (18).

A drive train control method includes transmitting a total time period of a stroke phase and a torque phase of an upshift from a transmission control unit of an automatic transmission to an engine control unit of an engine. The method also includes closing a first shift element of the automatic transmission and opening a second shift element of the automatic transmission during the upshift. A control pressure of the first shift element increases during the torque phase relative to the control pressure of the first shift element at an end of the stroke phase. A control pressure of the second shift element decreases during the torque phase relative to the control pressure of the second shift element at the end of the stroke phase. The method further includes, based at least in part on the total time period of the stroke and torque phases, increasing an actual torque of the engine during the upshift such that the actual torque of the engine increases to a higher gear torque prior to an end of the torque phase.

A hydro-mechanical transmission device with a dual-clutch transmission includes an input mechanism, a pump-controlled motor mechanism, an odd-numbered gear transmission mechanism, an even-numbered gear transmission mechanism, an output mechanism, and a jackshaft. The input mechanism is connected to the odd-numbered gear transmission mechanism and the even-numbered gear transmission mechanism that are connected in parallel, and is connected to an input end of the pump-controlled motor mechanism. An output end of the pump-controlled motor mechanism is connected, through the jackshaft, to the odd-numbered gear transmission mechanism and the even-numbered gear transmission mechanism that are connected in parallel, and is connected to the output mechanism. Switching among hydraulic transmission, hydro-mechanical transmission, and mechanical transmission modes between the input mechanism and the output mechanism is implemented by controlling combination and engagement/disengagement of clutches and a brake.

A powershift transmission for a work vehicle includes a speed section. Within the speed section, a speed C clutch is engageable to transfer rotational power from a speed input shaft to a speed countershaft via first and second speed gears, a speed A clutch is engageable to transfer rotational power from the speed input shaft to the speed countershaft via third and fourth speed gears, and a speed B clutch is engageable to transfer rotational power from the speed input shaft to the speed countershaft via fifth and sixth speed gears. A first gear ratio between the first and second speed gears is greater than a second gear ratio between the third and fourth speed gears and a third gear ratio between the fifth and sixth speed gears.

A power transmission apparatus for a hybrid electric vehicle may employ two clutches, two brakes, a dog clutch unit to a planetary gear train of having three planetary gear sets, and thereby provide various shifting modes such as an engine mode and a parallel hybrid mode of multiple shift-stages, an electronically-controlled continuously variable shifting mode, and an electric vehicle mode.

An electro-hydraulic control system for a multispeed transmission having a plurality of torque-transmitting mechanisms includes a controller for operably controlling the transmission, a fluid source for supplying hydraulic fluid, and a plurality of torque-transmitting mechanisms being operably selected between an applied and an unapplied state to achieve a plurality of ranges including at least one reverse, a neutral, and a plurality of forward ranges. The system includes a plurality of trim systems having pressure control solenoids and trim valves. The system may also include one or more shift valves disposed in fluid communication with the fluid source and being capable of moving between stroked and de-stroked positions. In any given range, only two of the plurality of torque-transmitting mechanisms may be applied. Moreover, three of the plurality of pressure control solenoids are normally high solenoids, and the remaining solenoids are normally low solenoids.