When the carrier is the held member, the result is always ___________ and the carrier pinions act as idler gears.

When the carrier is the held member, the result is always ___________ and the carrier pinions act as idler gears.

• A. direct drive
• B. a forward overdrive
• C. reverse
• D. a forward reduction

Answer: (C)

In a planetary gear set, holding the carrier fixed makes the planet gears rotate on their own shafts and act as simple idlers between the sun gear and the ring gear. Because idler gears reverse the direction of rotation, the motion from the sun to the ring passes through the planets and ends up turning in the opposite direction. With the carrier held, the output (typically the ring) moves opposite to the input, so the result is reverse. The exact speed depends on tooth counts, but the direction is reversed. Direct drive or same-direction outcomes (forward overdrive or forward reduction) don’t occur when the carrier is held, since the planets must reverse the direction between sun and ring.

In a planetary gear set, holding the carrier fixed makes the planet gears rotate on their own shafts and act as simple idlers between the sun gear and the ring gear. Because idler gears reverse the direction of rotation, the motion from the sun to the ring passes through the planets and ends up turning in the opposite direction. With the carrier held, the output (typically the ring) moves opposite to the input, so the result is reverse. The exact speed depends on tooth counts, but the direction is reversed. Direct drive or same-direction outcomes (forward overdrive or forward reduction) don’t occur when the carrier is held, since the planets must reverse the direction between sun and ring.