Sprag Clutch Backstop

Custom designed and configured specifically for a Marley Geareducer with input shaft diameters of 2.375” and 2.625”. Also referred to as a sprag clutch anti-rotation device, these units are designed to prevent reverse rotation of the fan, Geareducer and motor. Designed specifically for use with the current 32.2, 3400 and 4000 Geareducer models, they can also be utilized to fit legacy 32.1T, 34.3T, 34.4, 36 and 38 Geareducer models.

When operating, the outer race is stationary and the inner race is rotating. When facing the input shaft of the Geareducer, the forward (over-running) direction is clockwise.

In contrast to conventional sprag clutch devices which may continuously wear, this device utilizes a “Lift-off” sprag functionality which alleviates the wear issue once typical rotation speeds are reached.
This feature greatly diminishes the friction and heat generated, thus promoting longevity for both the clutch unit and the Geareducer itself.