Which statement correctly identifies what the flex coupler connects?

• A. Generator to the high-speed shaft of the gearbox
• B. Hub adapter to the gearbox
• C. Slip ring to the main shaft
• D. Main bearing to the low-speed shaft

Answer: (B)

A flex coupler is a flexible mechanical link that transmits torque between two rotating parts while absorbing vibration and allowing a bit of misalignment. In this setup, the hub adapter is the piece that mounts onto the gearbox input shaft, and the flex coupler sits between that hub adapter and the gearbox to transfer power from the drive side into the gearbox. This arrangement lets the drive connect smoothly to the gearbox while tolerating small alignment differences, which reduces stress on the shafts and bearings. The other options involve components or roles that aren’t about transmitting torque between shafts (such as electrical connections or bearing supports), so they aren’t what the flex coupler connects.