The planetary gear set can be used to create ______, allowing torque and speed to pass through the gear set unchanged.

The planetary gear set can be used to create ______, allowing torque and speed to pass through the gear set unchanged.

• A. Minimum forward overdrive
• B. No axial thrust
• C. No radial thrust
• D. A direct drive

Answer: (D)

A direct drive is possible with a planetary gear set, meaning the input and output can rotate at the same speed so torque and speed pass through essentially unchanged aside from small losses. This happens when the gearing is arranged so no net speed change occurs between the input element and the output element, effectively letting the planetary set act like a solid shaft for power transfer. The idea isn’t about eliminating all forces, because real gear sets still experience bearing loads (radial and axial) during operation, but it is possible to configure the system for a 1:1 transfer. The other options describe speed changes or force directions that aren’t the defining feature of a 1:1 transfer through a planetary set.

A direct drive is possible with a planetary gear set, meaning the input and output can rotate at the same speed so torque and speed pass through essentially unchanged aside from small losses. This happens when the gearing is arranged so no net speed change occurs between the input element and the output element, effectively letting the planetary set act like a solid shaft for power transfer. The idea isn’t about eliminating all forces, because real gear sets still experience bearing loads (radial and axial) during operation, but it is possible to configure the system for a 1:1 transfer. The other options describe speed changes or force directions that aren’t the defining feature of a 1:1 transfer through a planetary set.