The electrically variable transmission family of the present invention
provides low-content, low-cost electrically variable transmission
mechanisms including first and second differential gear sets, a battery,
two electric machines serving interchangeably as motors or generators,
five selectable torque-transfer devices, and a dog clutch. The selectable
torque transfer devices are engaged singly or in combinations of two,
three or four to yield an EVT with a continuously variable range of
speeds (including reverse) and up to four mechanically fixed forward
speed ratios. The torque transfer devices and the first and second
motor/generators are operable to provide five operating modes in the
electrically variable transmission, including battery reverse mode, EVT
reverse mode, reverse and forward launch modes, continuously variable
transmission range mode, and fixed ratio mode.