Patent ID: 8602938

Claim:
A powertrain for a hybrid vehicle, the powertrain comprising: a ferrite magnet motor; a rare earth magnet motor; an internal combustion engine; and a transmission including: an output configured for transmitting a torque to at least one wheel of the vehicle; a first planetary gearset connected to the output, the ferrite magnet motor, and the internal combustion engine; a second planetary gearset connected to the output and the rare earth magnet motor; a first torque transmitting mechanism selectively engaging and disengaging the second planetary gearset, wherein the first torque transmitting mechanism provides a reaction torque to the second planetary gearset when the first torque transmitting mechanism is engaged; and a second torque transmitting mechanism selectively connecting and disconnecting torque transmission between the ferrite magnet motor and a node of the second planetary gearset, wherein the second torque transmitting mechanism connects the ferrite magnet motor and the second planetary gearset when engaged to allow torque transmission therebetween, and wherein the second torque transmitting mechanism disconnects the ferrite magnet motor and the second planetary gearset when disengaged to prevent torque transmission therebetween; wherein the transmission is operable in a fixed gear mode with both the first torque transmitting mechanism and the second torque transmitting mechanism engaged and the internal combustion engine operating to eliminate torque dependent losses in the ferrite magnet motor; and wherein the transmission is operable in an electrically variable transmission mode with the first torque transmitting mechanism disengaged, the second torque transmitting mechanism engaged, and the internal combustion engine operating, such that the rare earth magnet motor provides a reaction torque for the ferrite magnet motor so that the ferrite magnet motor operates in a high speed/low torque condition to minimize torque dependent losses in the ferrite magnet motor.