In a planetary gear set there are at least how many sets of teeth transmitting the torque?

In a planetary gear set there are at least how many sets of teeth transmitting the torque?

• A. One
• B. Three
• C. Two
• D. Five

Answer: (B)

In a planetary gear set, three gear bodies carry the torque: the sun gear, the planet gears, and the ring gear. The sun gear’s teeth mesh with the planet gears, and those planet gears mesh with the ring gear’s internal teeth. The power flow passes through these engagements, with the carrier carrying the planet gears to the output. Since each of these gear types has teeth that participate in transmitting torque, there are at least three sets of teeth involved in the torque transmission.

In a planetary gear set, three gear bodies carry the torque: the sun gear, the planet gears, and the ring gear. The sun gear’s teeth mesh with the planet gears, and those planet gears mesh with the ring gear’s internal teeth. The power flow passes through these engagements, with the carrier carrying the planet gears to the output. Since each of these gear types has teeth that participate in transmitting torque, there are at least three sets of teeth involved in the torque transmission.