Which device prevents reverse rotation of the worm gear, roller chain and friction brake?

Which device prevents reverse rotation of the worm gear, roller chain and friction brake?

• A. Roller chain
• B. Stabilizer ring
• C. Positive drive belt
• D. Backstop clutch

Answer: (D)

A backstop clutch is used to prevent motion from reversing in a drive system. It acts as a one-way device: when the system turns in the intended forward direction, it transmits torque, but if reverse rotation starts to occur, the clutch elements (sprags or rollers) wedge or lock, stopping the shaft from rotating backward. In a setup with a worm gear, roller chain, and a friction brake, reverse rotation can back-drive the mechanism if power is removed. The backstop clutch provides positive locking to stop that backdrive, protecting the chain and brake from reverse motion and keeping the load from drifting when the drive isn’t active. A roller chain by itself only transmits motion; it doesn’t prevent backdriving. A stabilizer ring mainly helps with alignment or axial stability, not locking against reverse rotation. A positive drive belt transmits power but does not inherently lock the system against reverse motion.

A backstop clutch is used to prevent motion from reversing in a drive system. It acts as a one-way device: when the system turns in the intended forward direction, it transmits torque, but if reverse rotation starts to occur, the clutch elements (sprags or rollers) wedge or lock, stopping the shaft from rotating backward.

In a setup with a worm gear, roller chain, and a friction brake, reverse rotation can back-drive the mechanism if power is removed. The backstop clutch provides positive locking to stop that backdrive, protecting the chain and brake from reverse motion and keeping the load from drifting when the drive isn’t active.

A roller chain by itself only transmits motion; it doesn’t prevent backdriving. A stabilizer ring mainly helps with alignment or axial stability, not locking against reverse rotation. A positive drive belt transmits power but does not inherently lock the system against reverse motion.