A planetary gearbox including a first sun gear; a first ring gear; a first set of planet gears meshing with the first sun gear and the first ring gear; a second sun gear; a second ring gear; a second plurality of planet gears meshing with the second ring gear and the second sun gear, wherein the i.sup.th gear in the first set of planet gears is fixed to the i.sup.th gear in the second set of planet gears so that the gears in the first set and the second set rotate together coaxially. The resulting planetary gearbox can be readily integrated into compact robotic joints. Its few lightweight components can be manufactured with high accuracy with standard machining techniques.

A planetary gearbox including a first sun gear; a first ring gear; a first set of planet gears meshing with the first sun gear and the first ring gear; a second sun gear; a second ring gear; a second plurality of planet gears meshing with the second ring gear and the second sun gear, wherein the i.sup.th gear in the first set of planet gears is fixed to the i.sup.th gear in the second set of planet gears so that the gears in the first set and the second set rotate together coaxially. The resulting planetary gearbox can be readily integrated into compact robotic joints. Its few lightweight components can be manufactured with high accuracy with standard machining techniques.

The present invention provides a changeable linear speed reduction clutch, which is formed by connecting a changeable linear speed double-layer planetary gear train and a brake, and is transmission machinery with functions of both a speed reducer and a clutch. A planetary carrier of the changeable linear speed double-layer planetary gear train is used as an input end, one central gear as an output end, the other central gear as a braking end, and the braking end is directly connected to the brake; and the changeable linear speed double-layer planetary gear train adopts one of two types of planetary gear trains. The brake at least has two states, that is, braking and non-braking states, wherein the braking state of the brake is equivalent to an engaged state of the clutch, and the non-braking state of the brake is equivalent to a disengaged state of the clutch. The method of setting the changeable linear speed double-layer planetary gear train, and the application method of the present invention are provided herein. Compared with a device in which a multi-stage speed reducer and a clutch are arranged independently, the changeable linear speed reduction clutch in the present invention is small and light and has a simple structure.

A transmission may include a compound planetary gear set; a first clutch provided to transmit power of an input shaft to a second rotation element of the compound planetary gear set; a third clutch provided to transmit the power of the input shaft to a third rotation element of the compound planetary gear set; an overdrive provided to increase the power of the input shaft; a second clutch provided to transmit the power through the overdrive from the input shaft to the second rotation element of the compound planetary gear set; a fourth clutch provided to transmit the power through the overdrive from the input shaft to a fourth rotation element of the compound planetary gear set; a first brake provided to selectively stop rotation of the third rotation element of the compound planetary gear set; and a second brake provided to selectively stop rotation of the fourth rotation element of the compound planetary gear set.

A transmission may include a compound planetary gear set; a first clutch provided to transmit power of an input shaft to a second rotation element of the compound planetary gear set; a third clutch provided to transmit the power of the input shaft to a third rotation element of the compound planetary gear set; an overdrive provided to increase the power of the input shaft; a second clutch provided to transmit the power through the overdrive from the input shaft to the second rotation element of the compound planetary gear set; a fourth clutch provided to transmit the power through the overdrive from the input shaft to a fourth rotation element of the compound planetary gear set; a first brake provided to selectively stop rotation of the third rotation element of the compound planetary gear set; and a second brake provided to selectively stop rotation of the fourth rotation element of the compound planetary gear set.

A transmission assembly includes a transmission housing. A first gearset includes first, second and third rotating elements disposed within the transmission housing. A second gearset includes fourth, fifth and sixth rotating elements disposed within the transmission housing adjacent the first gearset. An output shaft is connected to the third rotating element of the first gearset and the fifth rotating element of the second gearset. An input shaft is connected to the fourth rotating element of the second gearset. A controllable clutch is connected between the input shaft at a first end and the output shaft at a second end. A first controllable brake selectively couples the first rotating element to the transmission housing. A second controllable brake selectively couples the second rotating element of the first gearset and the sixth rotating element of the second gearset to the transmission housing, such that the first and second controllable clutches and the first and second controllable brakes control the torque of the output shaft as a function of forces driving the first and second input shafts.

A transmission assembly includes a transmission housing. A first gearset includes first, second and third rotating elements disposed within the transmission housing. A second gearset includes fourth, fifth and sixth rotating elements disposed within the transmission housing adjacent the first gearset. An output shaft is connected to the third rotating element of the first gearset and the fifth rotating element of the second gearset. An input shaft is connected to the fourth rotating element of the second gearset. A controllable clutch is connected between the input shaft at a first end and the output shaft at a second end. A first controllable brake selectively couples the first rotating element to the transmission housing. A second controllable brake selectively couples the second rotating element of the first gearset and the sixth rotating element of the second gearset to the transmission housing, such that the first and second controllable clutches and the first and second controllable brakes control the torque of the output shaft as a function of forces driving the first and second input shafts.

A transmission may include a compound planetary gear set; a first clutch provided to transmit power of an input shaft to a second rotation element of the compound planetary gear set; a third clutch provided to transmit the power of the input shaft to a third rotation element of the compound planetary gear set; an overdrive provided to increase the power of the input shaft; a second clutch provided to transmit the power through the overdrive from the input shaft to the second rotation element of the compound planetary gear set; a fourth clutch provided to transmit the power through the overdrive from the input shaft to a fourth rotation element of the compound planetary gear set; a first brake provided to selectively stop rotation of the third rotation element of the compound planetary gear set; and a second brake provided to selectively stop rotation of the fourth rotation element of the compound planetary gear set.

A transmission may include a compound planetary gear set; a first clutch provided to transmit power of an input shaft to a second rotation element of the compound planetary gear set; a third clutch provided to transmit the power of the input shaft to a third rotation element of the compound planetary gear set; an overdrive provided to increase the power of the input shaft; a second clutch provided to transmit the power through the overdrive from the input shaft to the second rotation element of the compound planetary gear set; a fourth clutch provided to transmit the power through the overdrive from the input shaft to a fourth rotation element of the compound planetary gear set; a first brake provided to selectively stop rotation of the third rotation element of the compound planetary gear set; and a second brake provided to selectively stop rotation of the fourth rotation element of the compound planetary gear set.

In the case of an axle drive unit with a power-shiftable two-speed transmission unit, in order to enable particularly simple and advantageous control of a gear change and to manage with a small number of components and a less complex control logic and control sensor system, the coordination of mechanically-passively implemented shifting thresholds of a friction clutch and a blocking device of a freewheel is provided, which makes it possible to control the friction clutch and the blocking device with the same control variable at always the same level.