Electrically variable transmission
View Patent ↗A powertrain having a fuel cell prime mover, an electronic control unit, two motor/generator units, two planetary gearsets, and a plurality of torque-transmitting mechanisms is operable to provide three ranges of operation. During one range of operation, the power take-off unit operates at a constant speed. During the second range of operation, the power take-off unit, one of the motor/generator units, and the output shaft operate at a same speed, and during the third range of operation, both motor/generator units, the output shaft, and the power take-off unit operate at a same speed.
1. An electromechanical powertrain including a transmission comprising:
a fuel cell power source;
an electrical energy storage means;
an electronic control unit connected between said fuel cell power source and said electrical energy storage means;
a transmission output shaft;
a transmission housing;
a first electrical power transfer machine electrically connected with both said fuel cell power source and said electrical energy means through said electronic control unit;
a second electrical power transfer machine electrically connected with both said fuel cell power source and said electrical energy means through said electronic control unit;
power take-off means for supplying power to operate accessories;
a first planetary gearset having a first member continuously rotatable with said first electrical power transfer machine, a second member continuously rotatable with said output shaft, and a third member continuously rotatable with said power take-off means;
a second planetary gearset having a first member continuously rotatable with said second electrical power transfer machine, a second member continuously rotated with said second member of said first planetary gearset and with said output shaft, and a third member;
a first torque-transmitting mechanism selectively connectable between said transmission housing and said third member of said second planetary gearset;
a second torque-transmitting mechanism selectively connectable between said third member of said second planetary gearset and said output shaft;
a third torque-transmitting mechanism selectively connectable between said third member and said second member of said first planetary gearset to provide a 1:1 drive from said first electrical power transfer machine to said power take-off means; and
said first torque-transmitting mechanism being engaged for a first range of operation, said second torque-transmitting mechanism being engaged for a second range of operation, and said third torque-transmitting mechanism being engaged to cause unitary rotation of said first electrical power transfer machine, said power take-off means and said output shaft, and operating in cooperation with the engagement of said second torque-transmitting mechanism to cause conjoint rotation of said first electrical power transfer machine, said second electrical power transfer machine, said power take-off means, and said output shaft.
2. The electromechanical powertrain including a transmission defined in claim 1 further comprising:
said third torque-transmitting mechanism comprising a one-way torque-transmitting mechanism disposed between said first electrical power transfer machine and said power take-off means.
3. The electromechanical powertrain including a transmission defined in claim 1 further comprising:
said first member of said first planetary gearset being a planet carrier member, said second member of said first planetary gearset being a ring gear member, and said third member of said first planetary gearset being a sun gear member; and
said first member of said second planetary gearset being a sun gear member, said second member of said second planetary gearset being a planet carrier member, and said third member of said second planetary gearset being a ring gear member.