If the sun gear is the output component, what result is achieved?

If the sun gear is the output component, what result is achieved?

• A. Reverse reduction
• B. Maximum forward overdrive
• C. Reverse overdrive
• D. Minimum forward overdrive

Answer: (B)

In a planetary gear set, how fast each part turns depends on which member you drive and which you lock in place. Overdrive means the output spins faster than the input in the same direction. If the sun gear becomes the output and the ring gear is held, the planets mesh in a way that forces the sun to rotate faster than the input carrier. The fixed ring creates a condition where the sun’s speed, relative to the input, is multiplied the most in the forward direction. That’s why this arrangement yields forward overdrive, and specifically the maximum forward overdrive, compared with other configurations where the output would be reduced or could even reverse.

In a planetary gear set, how fast each part turns depends on which member you drive and which you lock in place. Overdrive means the output spins faster than the input in the same direction.

If the sun gear becomes the output and the ring gear is held, the planets mesh in a way that forces the sun to rotate faster than the input carrier. The fixed ring creates a condition where the sun’s speed, relative to the input, is multiplied the most in the forward direction. That’s why this arrangement yields forward overdrive, and specifically the maximum forward overdrive, compared with other configurations where the output would be reduced or could even reverse.