In reverse, the carrier is the held member of the planetary gear set. Who is correct about the behavior?

In reverse, the carrier is the held member of the planetary gear set. Who is correct about the behavior?

• A. Technician A
• B. Technician B
• C. Both Technician A and Technician B
• D. Neither Technician A nor Technician B

Answer: (A)

In a planetary gear set, which member is held fixed determines how the other parts move and what direction the output takes. When the carrier is held, driving the sun gear causes the planet gears to spin around the sun, and the ring gear must rotate to mesh with them. Because the gears are arranged so that the ring gear moves opposite to the sun gear, the output ends up rotating in the reverse direction relative to the input. This is why saying that the carrier is held in reverse matches the actual motion of the gear set in that mode. Holding a different member would produce a different output direction, so describing reverse as the carrier being fixed aligns with the observed behavior.

In a planetary gear set, which member is held fixed determines how the other parts move and what direction the output takes. When the carrier is held, driving the sun gear causes the planet gears to spin around the sun, and the ring gear must rotate to mesh with them. Because the gears are arranged so that the ring gear moves opposite to the sun gear, the output ends up rotating in the reverse direction relative to the input. This is why saying that the carrier is held in reverse matches the actual motion of the gear set in that mode. Holding a different member would produce a different output direction, so describing reverse as the carrier being fixed aligns with the observed behavior.