Multi-mode drive unit
View Patent ↗Multi-mode operation is provided for an electrically variable transmission for a motor vehicle. The multi-mode electrically variable transmission provides for multiple gear ratios and power flow configurations including fixed gear operation. An improved input-split planetary gear set configuration is provided for the multi-mode electrically variable transmission. The multi-mode electrically variable transmission may be operated in its desired efficiency and/or performance range more frequently. Further, the transmission reduces clutch torques and provides improved functionality in range-extended electric vehicles and battery electric vehicles. The multi-mode electrically variable transmission is provided with a fixed gear operating capability for improved highway cruising and incorporates a reverse gear for reverse operation.
1. A transmission comprising:
a transmission input shaft;
a first planetary gear set comprising:
a first sun gear,
at least two first pinion gears meshed with the first sun gear,
a first carrier coupled to the at least two first pinion gears and the transmission input shaft, and
a first ring gear meshed with the at least two first pinion gears;
a first electric motor coupled to the first sun gear;
a second electric motor coupled to the first ring gear; and
an output gear selectively coupled to the first electric motor to provide a first transmission gear ratio and selectively coupled to the second electric motor to provide a second transmission gear ratio;
a first driver gear selectively coupled to the first electric motor and meshed with a first driven gear, the first driven gear being coupled to the output gear;
a second driver gear selectively coupled to the second electric motor and meshed with a second driven gear, the second driven gear being coupled to the output gear;
a reverse driver gear selectively coupled to the second electric motor;
a reverse idler gear meshed with the reverse driver gear; and
a reverse driven gear meshed with the reverse idler gear, the reverse driven gear being coupled to the output gear to provide a reverse gear ratio.
2. The transmission of claim 1 , wherein:
the first electric motor is selectively coupled to the output gear by a first clutch mechanism; and
the second electric motor is selectively coupled to the output gear by a second clutch mechanism.
3. The transmission of claim 1 , further comprising:
a first gear coupled to the second electric motor; and
a second gear meshed with the first gear and selectively coupled to the output gear.