Multi-speed drive unit
View Patent ↗A multi-speed drive unit is provided for an electrically variable transmission having a variable-range output gear ratio for a motor vehicle. The variable-range output electrically variable transmission has improved final drive gear ratios that allow the motor to be operated in its desired efficiency and/or performance range during both city and highway vehicle operation. Further, the variable-range output electrically variable transmission allows for increased vehicle speeds during electric vehicle operation and provides for the use of the vehicle engine during reverse gear operation.
1. A transmission comprising:
a transmission input shaft;
a planetary gear set comprising:
a sun gear,
at least one pinion gear meshed with the sun gear, the at least one pinion gear coupled to the transmission input shaft by a carrier, and
a ring gear continuously meshed with the at least one pinion gear;
a first electric motor coupled to the sun gear;
a second electric motor selectively coupled to the ring gear;
a first driver gear and a second driver gear, wherein the second electric motor is selectively coupled to the first driver gear to provide a first output gear ratio and selectively coupled to the second driver gear to provide a second output gear ratio;
a reverse driver gear selectively coupled to the second electric motor; and
a reverse idler gear continuously meshed with the reverse driver gear to provide a reverse gear ratio.
2. The transmission of claim 1 , wherein the ring gear is selectively coupled to ground.
3. The transmission of claim 1 , wherein the selectively coupling is performed by a plurality of clutch mechanisms.
4. The transmission of claim 3 , wherein the clutch mechanisms are chosen from the group consisting of dry clutches, wet clutches, multi-plate clutches, dog clutches, synchronizer mechanisms, or dual clutches.
5. A transmission comprising:
a transmission input shaft;
a planetary gear set comprising:
a sun gear,
at least one pinion gear continuously meshed with the sun gear, the at least one pinion gear coupled to the transmission input shaft by a carrier, and
a ring gear continuously meshed with the at least one pinion gear;
a first electric motor coupled to the sun gear;
a second electric motor selectively coupled to the ring gear, wherein:
the second electric motor is selectively coupled by a first clutch mechanism to a first driver gear,
the second electric motor is selectively coupled by a second clutch mechanism to a second driver gear, and
the second electric motor is selectively coupled by a third clutch mechanism to the ring gear;
an output layshaft, the output layshaft comprising:
a first final drive pinion coupled to the output layshaft and continuously meshed with the first driver gear,
a second final drive pinion coupled to the output layshaft and continuously meshed with the second driver gear, and
an output gear coupled to the output layshaft;
a reverse final drive pinion selectively coupled by a fourth clutch mechanism to the second electric motor; and
a reverse idler gear continuously meshed with the reverse driver gear,
wherein the output layshaft further comprises a reverse final drive pinion coupled to the output layshaft and continuously meshed with the reverse idler gear.
6. The transmission of claim 5 , further comprising a fifth clutch mechanism selectively coupling the ring gear to ground.
7. The transmission of claim 5 , wherein the first clutch mechanism and the second clutch mechanism are the same.
8. The transmission of claim 5 , wherein the fourth clutch mechanism selectively couples the second electric motor to the second driver gear.