A power transmission apparatus of a hybrid electric vehicle may include a first shaft fixedly connected to an engine, a second shaft selectively connectable to the first shaft and fixedly connected to a motor-generator, a third shaft disposed on a same axis with the first shaft and selectively connectable to the second shaft, a fourth shaft disposed coaxially with the third shaft without rotational interference therebetween, a fifth shaft disposed in parallel with the third and fourth shafts and externally gear-meshed with the third and fourth shafts, a planetary gear set having three elements, one element being fixedly connected to the second shaft, another element being selectively connectable to a transmission housing, and a remaining element being fixedly connected to the fourth shaft, and four gear sets forming gear engagements between the first shaft, the second shaft, the third shaft, the fourth shaft and the fifth shaft.

The disclosure reduces the number of factors to be considered in the switching control of the shift stages, thereby simplifying the switching control. In a control device of an automatic transmission, when a detection part detects that a shift position has been switched from one of a forward range and a reverse range to the other, among multiple hydraulic friction engagement mechanisms, a hydraulic pressure command value is fixed for the hydraulic friction engagement mechanisms that do not change the engaged state between the forward range and the reverse range, and the hydraulic pressure command value is variable based on a hydraulic pressure supplied to the hydraulic friction engagement mechanisms for the hydraulic friction engagement mechanisms that change the engaged state between the forward range and the reverse range.

A power transmission apparatus of a hybrid electric vehicle may include a first shaft fixedly connected to an engine, a second shaft selectively connectable to the first shaft and fixedly connected to a motor-generator, a third shaft disposed on a same axis with the first shaft and selectively connectable to the second shaft, a fourth shaft disposed coaxially with the third shaft without rotational interference therebetween, a fifth shaft disposed in parallel with the third and fourth shafts and externally gear-meshed with the third and fourth shafts, a planetary gear set having three elements, one element being fixedly connected to the second shaft, another element being selectively connectable to a transmission housing, and a remaining element being fixedly connected to the fourth shaft, and four gear sets forming gear engagements between the first shaft, the second shaft, the third shaft, the fourth shaft and the fifth shaft.

A shift-type multi-phase-shifter drive transmission device includes a drive device (3), a shifting mechanism, multiple angle adjustment mechanisms and multiple ruler mechanisms. When the shift-type drive transmission device works, the drive device (3) firstly drives a shifting rack (11) of the shifting mechanism to move to a position which is corresponding to one of the angle adjustment mechanisms, a shifting bulge (111) on the shifting rack (11) is against a driving lever (13) for engaging an active clutch gear (16) with a passive clutch gear (17) of the corresponding angle adjustment mechanism, so as to further drive a transmission screw (19), thus a transmission nut (20) on the transmission screw (19) implements the reciprocating linear motion. The shift-type drive transmission device is able to drive multiple phase shifters through one drive device (3) to perform angle adjustment, which reduces an amount of the drive sources and effectively decreases cost.

A drive system includes a first gear set and a second gear set, each including a sun gear, a ring gear, a plurality of planetary gears coupling the sun gear to the ring gear, and a carrier rotationally supporting the plurality of planetary gears, a first electrical machine directly coupled to the first gear set, a second electrical machine directly coupled to the second gear set, a connecting shaft directly coupled to the ring gear of the first gear set, a driveshaft that transports power from the electrical machines to a tractive element, a first clutch selectively rotationally coupling the first gear set and the second gear set to the driveshaft, and at least one of a second clutch selectively rotationally coupling the second electrical machine to the connecting shaft and a third clutch selectively rotationally coupling the second gear set to the driveshaft.

A vehicle includes a connecting shaft, a drive axle, a multi-mode transmission, and a controller. The multi-mode transmission includes a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, a first motor/generator coupled to the first gear set, a second motor/generator electrically coupled to the first motor/generator and coupled to the second gear set, a brake selectively limiting movement of a portion of the second gear set, and a clutch selectively rotationally coupling the second motor/generator to the connecting shaft. The first gear set is coupled to the connecting shaft, and the planetary gear carriers are rotatably coupled. The controller is configured to selectively configure the multi-mode transmission into an active neutral startup mode of operation by engaging the clutch and the brake such that at least one of the first motor/generator and the second motor/generator produces a voltage.

A drive system for a vehicle includes first and second electrical machines, a transmission, and an electrical energy supply. The transmission includes first and second gear sets, a connecting shaft coupled to the first gear set, a driveshaft configured to transport power from the electrical machines to a tractive element of the vehicle, and a clutch. The first gear set is coupled to the first electrical machine. The second gear set is coupled to the second electrical machine. Carriers of the first and second gear sets are coupled. The clutch selectively rotationally couples the carriers to the driveshaft when engaged. The drive system operates in an electric only configuration whereby the electrical energy supply provides electrical energy to at least one of the electrical machines to drive at least one of the connecting shaft and the driveshaft without a mechanical energy input to the transmission from an engine.

A drive system for a vehicle includes a first electromagnetic device directly coupled to a first planetary gear set and a second electromagnetic device directly coupled to a second planetary gear set. In a first mode of operation, a clutch is engaged to couple the second planetary gear set to the first planetary gear set and a brake is disengaged to allow rotation of the second planetary gear set and in a second mode of operation, the brake is engaged to limit rotation of the second planetary gear set and the clutch is disengaged.

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 disclosure reduces the number of factors to be considered in the switching control of the shift stages, thereby simplifying the switching control. In a control device of an automatic transmission, when a detection part detects that a shift position has been switched from one of a forward range and a reverse range to the other, among multiple hydraulic friction engagement mechanisms, a hydraulic pressure command value is fixed for the hydraulic friction engagement mechanisms that do not change the engaged state between the forward range and the reverse range, and the hydraulic pressure command value is variable based on a hydraulic pressure supplied to the hydraulic friction engagement mechanisms for the hydraulic friction engagement mechanisms that change the engaged state between the forward range and the reverse range.