How does backstop functionality work in a bevel gearbox?

The backstop mechanism in a bevel gearbox prevents reverse rotation of the output shaft, since bevel gears are not self-locking. It is typically implemented using one of the following methods:

• Overrunning clutch (e.g. roller or cam type): Allows rotation in one direction only and automatically blocks reverse motion.
• Mechanical lock (e.g. pawl or ratchet): Rigidly locks the shaft, typically when stationary.
• Electromechanical brake (e.g. motor holding brake): Prevents backdriving through targeted braking in case of power failure or standstill.

These mechanisms are added to the bevel gearbox, as the gear itself does not provide inherent reverse rotation protection.