A power transmission apparatus may include engine; first motor/generator; first rotation element fixed to the engine, second rotation element fixed to the first motor/generator, and third rotation element; first input shaft selectively connectable to the third rotation element; second input shaft selectively connectable to the third rotation element; third input shaft; an output shaft; an idle shaft operably connected to the second input shaft and the third input shaft; and speed stage module including drive gears rotatably disposed on the first input shaft, the third input shaft, or the idle shaft, driven gears meshed with the drive gears and fixed on the output shaft, and power delivery gears and an idle gear fixed on the second input shaft, the third input shaft, or the idle shaft, and synchronizers selectively connecting at least one among the drive gears to the first input shaft, the third input shaft, or the idle shaft.

A multi-speed transmission may include a plurality of planetary gearsets and a plurality of selective couplers. The plurality of planetary gearsets may include a first planetary gearset, a second planetary gearset, a third planetary gearset, a fourth planetary gearset, and a fifth planetary gearset. The plurality of selective couplers may include a number of clutches and a number of brakes. The multi-speed transmission may have five planetary gearsets and seven selective couplers. The seven selective couplers may include two clutches and five brakes or three clutches and three brakes.

Methods and systems for a multi-ratio gear box and four speed transmission are provided. In one example, a first shaft is coupled to one or more input speed reduction gear sets. A second shaft is coupled to a multi-range clutch having a first position and a second position allowing for two speeds. A third shaft is coupled to a low-speed clutch and a fourth shaft is coupled to a high-speed clutch, together doubling the number of speeds. The high and low-speed clutches provide a large gear spread that allow the multi-range clutches to have a reduced gear spread, overall reducing the required size of the transmission. A fifth shaft, coupled to the fourth shaft via a gear, may be an output shaft spaced away from the electric motors, thereby creating a short flange to flange distance.

Provided herein is a dual clutch transmission including a reverse countershaft that is selectively engaged with at least one primary shaft and provides speed ratio changes without torque interruption and a compact axial arrangement.

The present document relates to a transmission assembly with multiple gear ratios, comprising: a range gearbox having at least two selectable range gear ratios and comprising a first shaft, a low/high speed mode selection unit for selecting a low-speed mode or a high-speed mode and comprising a third shaft and a first output shaft, wherein the range gearbox and the low/high speed mode selection unit being sequentially disposed in a downstream direction of a transmission power flow, and wherein the first shaft, the third shaft and the first output shaft are offset from one another.

A transmission device for a work vehicle includes an auxiliary transmission including forward gear shift stages for the work vehicle to move forward and a reverse gear shift stage for the work vehicle to move backward. The forward gear shift stages include a low-speed gear shift stage with a largest gear ratio among the plurality of forward gear shift stages, and a medium-speed gear shift stage with a gear ratio closest to a gear ratio of the reverse gear shift stage among the forward gear shift stages.

A method of synchronizing the countershaft speed, in the direct gear, for a hybrid application. The transmission (1) comprises a main transmission (HG) comprising two parallel partial transmissions with at least one countershaft (VW), an output shaft (3), and two planetary transmissions (PG1, PG2) each comprising a carrier (ST1, ST2), sun gear (SR1, SR2) and ring gear (HR1, HR2). Each partial transmission has a transmission input shaft (4, 5), with a hollow first input shaft (4) and the solid second input shaft (5). The first planetary transmission (PG1) connects as a range group to the main transmission (HG). The main transmission (HG) comprises first (R1), second (R2), third (R3), fourth (R4) and fifth gear planes (R5) and first (S1), second (S2), third (S3) and fourth shift elements (S4). Synchronization of the countershaft speed to a target speed, in direct gear, is performed via speed control of the electric machine (2).

A transmission and a method for operating an automated transmission having a main transmission group and at least one splitter group for producing at least six gears. The gear interval at least in a gearshift between the gears with the lowest and second-lowest gear ratios is chosen to be smaller than the gear interval at least between the gears with the highest and the second-highest gear ratios. At least in the gearshift between the gears with the lowest and second-lowest gear ratios, a shifting element in use associated with the splitter group and a shifting element in use associated with the main transmission group are changed. At least in a gearshift between the gears with the highest and the second-highest gear ratios, a shifting element in use associated with the main transmission group is not changed and a shifting element in use associated with the splitter group is changed.

A method is provided for controlling a gear shift from a forward gear to a reverse gear in a transmission arrangement, the method including the steps of: positioning a first locking mechanism and a first connecting mechanism at least in a partially engaged state for reducing a rotational speed of a planet carrier of a second planetary gear set; and positioning a second locking mechanism in an engaged state when a rotational speed of the planet carrier of the second planetary gear set is below a predetermined threshold limit.

A transmission arrangement for a vehicle includes a first, a second, a third, and a fourth planetary gear set including a sun gear, a planet carrier and a ring gear, respectively, wherein the transmission arrangement further includes a transmission housing, an input shaft and an output shaft, wherein the planet carrier of the first planetary gear set and the output shaft are operatively connected to each other; the ring gear of the first planetary gear set and the planet carrier of the second planetary gear set are operatively connected to each other; the sun gear of the first planetary gear set and the sun gear of the second planetary gear set are operatively connected to each other; the ring gear of the second planetary gear set and the planet carrier of the third planetary gear set are operatively connected to each other; and two of the sun gear, the planet carrier and the ring gear of the fourth planetary gear set are each operatively connected to a respective one of the input shaft, the sun gear, the planet carrier and the ring gear of the third planetary gear set.