Specification:

• This mechanism is a differential gear train whose gears are all spur gears.
• The mechanism is driven and both wheels are releasing free, all spur gears are running.
• The function of this mechanism is similar to the previous differential gear train.
• It is basically a combination of two planetary gear trains on which the two sun gears are coaxial.
• The right wheel is held, the right sun gear will become fixed but the other gears are still rotatable; when the left wheel is held, the left sun gear will become fixed but the other gears are still rotatable.
• This mechanism is applicable for the situation that requires two controllable inputs.