An apparatus for use in turning steerable vehicle wheels includes a steering column having a pinion connected with a vehicle steering wheel such that rotation of the steering wheel results in rotation of the pinion. An electrically powered steering unit includes an electric motor having a first output shaft rotatable about an axis. A first planetary gear stage has a first gear reduction ratio and is driven by the first output shaft. A second planetary gear stage is driven by the first planetary gear stage and the pinion and has a second gear reduction ratio different from the first gear reduction ratio. A second output shaft is driven by the second planetary gear stage and coupled to the steerable wheels such that rotation of the second output shaft affects steering of the vehicle wheels.

A transmission for an at least partially electrically driven vehicle includes two electric machines which are rotationally driveable in a first direction and in a second direction. The transmission further includes an output shaft at least indirectly operatively connected to the first and second electric machines, a first freewheel clutch that at least indirectly transmits a drive power of the first electric machine to the output shaft with a first ratio when the first electric machine rotates in the first direction, and a second freewheel clutch that at least indirectly transmits the drive power of the first electric machine to the output shaft with a second ratio when the first electric machine rotates in the second direction. Additionally, the transmission includes at least one first gear stage in power flow between the first or second freewheel clutch and the output shaft to rotate the output shaft in a third direction.

A shift control method for an automated manual transmission (AMT) of a vehicle includes: when a shift operation is started, a torque of the second motor is increased so that a change in an output torque of the output shaft due to a change in a torque of the first motor is minimized while the torque of the first motor is being decreased. According to the shift control method, the increased torque of the second motor is maintained to be constant while controlling transmission release, speed synchronization, and transmission coupling. After the control over the transmission coupling is completed, the torque of the second motor is controlled so that the output torque of the output shaft follows a predetermined target torque while the torque of the first motor is controlled to be increased.

A vehicle powertrain comprising a first and second electric machines, and a transmission arranged to transmit torque from said electric machines to a driving axle, the transmission comprising: first and second input shafts arranged to be driven by the machines, respectively, a common output shaft, a first gear set comprising:
first and second input gears via which torque is transmittable from the respective input shafts, to the output shaft; a second gear set comprising:
third and fourth input gears via which torque is transmittable from the respective input shafts to the output shaft; means for disconnecting each machine from each other and from the output shaft; an intermediate shaft drivable by the first and/or the second input gear; and an auxiliary gear set having two gear ratios arranged between the intermediate and common output shafts, at least the first gear set being arranged to drive the output shaft via the intermediate shaft and the auxiliary gear set.

A vehicle powertrain comprising a first and second electric machines, and a transmission arranged to transmit torque from said electric machines to a driving axle, the transmission comprising: first and second input shafts arranged to be driven by the machines, respectively, a common output shaft, a first gear set comprising:
first and second input gears via which torque is transmittable from the respective input shafts to the output shaft; a second gear set comprising:
third and fourth input gears via which torque is transmittable from the respective input shafts to the output shaft; means for disconnecting each machine from each other and from the output shaft an intermediate shaft drivable by the first and/or the second input gear; and an auxiliary gear set having two gear ratios arranged between the intermediate and common output shafts, at least the first gear set being arranged to drive the output shaft via the intermediate shaft and the auxiliary gear set.

A transmission for an opposed-piston engine with two crankshafts includes a crankshaft gear train that combines the torque inputs from the two crankshafts and a gear arrangement coupled to the gear train that is operable to obtain various speed ratios for an output torque drive.

In a series of reduction gears including a parallel shaft reduction gear and an orthogonal shaft reduction gear, the parallel shaft reduction gear includes a motor, a parallel shaft reducer, and a first joint unit, and the first joint unit includes a first joint casing which is connected to a motor casing and a parallel shaft reducer casing, and a joint shaft which is connected to a motor shaft and the input shaft of the parallel shaft reducer. The orthogonal shaft reduction gear includes the motor and the parallel shaft reducer which are used in common with the parallel shaft reduction gear, a second joint unit in which a portion or all portions are used in common with the first joint unit, and an orthogonal reducer, and the motor, the second joint unit, the orthogonal reducer, and the parallel shaft reducer are connected to one another in this order.

A motorized gear reducer is provided with a hollow motor in the housing and including an annular rotor having a through hole, and a shaft passing through the through hole; and a planetary gear train in the through hole and placed on the shaft, the planetary gear train including a sun gear assembly having a first sun gear in the housing, and a second sun gear on the shaft; planet gear assemblies equally spaced apart around the sun gear assembly, each including a first planet gear meshing with the first sun gear, and a second planet gear coaxially disposed with the first planet gear and meshing with the second sun gear; and a ring gear on an inner surface of the rotor. A speed reduction ratio of a first stage and a speed reduction ratio of a second stage are rendered.

A transmission for an at least partially electrically driven vehicle includes two electric machines which are rotationally driveable in a first direction and in a second direction. The transmission further includes an output shaft at least indirectly operatively connected to the first and second electric machines, a first freewheel clutch that at least indirectly transmits a drive power of the first electric machine to the output shaft with a first ratio when the first electric machine rotates in the first direction, and a second freewheel clutch that at least indirectly transmits the drive power of the first electric machine to the output shaft with a second ratio when the first electric machine rotates in the second direction. Additionally, the transmission includes at least one first gear stage in power flow between the first or second freewheel clutch and the output shaft to rotate the output shaft in a third direction.

A turbomachine dual spool transmission system can include a transmission assembly configured to connect to a combination output of a dual spool differential at a transmission input to be driven by the combination output to turn a transmission output. The transmission assembly can be configured to provide a first output gear ratio in a first state and a second output gear ratio in a second state. The system can include the dual spool differential. The dual spool differential can include a gear assembly configured to combine a low pressure spool input and a high pressure spool input into a combination output to provide an output speed range smaller than a low pressure speed range alone.