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1. FREEWHEEL ONE WAY CLUTCH » SPRAG CLUTCH » CAM CLUTCH » UNIDIRECTIONAL CLUTCH. 2. HOLDBACK DEVICE » BACK STOP DEVICE. 3. KEYLESS TRANSMISSION ELEMENTS » LOCKING ASSEMBLIES » SHRINK DISCS » LOCKING ELEMENTS » TAPER LOCK. 4. TENSIONER NUTS & BOLTS » SUPER BOLT. 5. CAM FOLLOWER » TRACK ROLLER
Hold Back Device - High speed shaft

Hold Back Device - High Speed Shaft

Positive protection against reverse torque runaways of inclined conveyor or elevator installations, and adequate provision for the safety of operating personnel can be assured   The NHB Models can be installed   at input shaft of Gearbox  OR with  NHB.c (Enclosed model - Freewheel bearing support and   cover protection) can be used exterior side.   

These units are having individually spring loaded centrifugally lift off sprag.

Used as overruning clutches,where the shaft overruns at high speed,

Technical Data

Main Features
  • Permissible wide radial run-out

  • The device is maintenance free

  • Wear free & long life

  • No special Lubrication required

  • Easy Assembly

Applications
  • In Inclined Conveyors, Elevators, Pumps, Blowers, Fans, Gear boxes, Electric Motors, Geared Motors, pumps & Compressors, Ball Mills, Engine Starter

In NHB model, Centrifugal lift-off Sprags are used. When inner race of the freewheel (shaft) rotates at high speed (during overrunning - freewheeling), due to centrifugal force, the sprags are to lift off towards the inner surface of outer race & develop gap between sprag and sprag contact surface of outer race. The freewheel is thus operating without any friction - contact free. In this operating mode, the freewheel runs wear free. When the speed of the inner race has dropped sufficiently to reduce the effect of the centrifugal force, the sprag relocate once again with the contact surface of the outer ring and the freewheel is ready to anti rotate. These backstops may also be operated below the lift-off speed. In that case either in oil bath or oil circulation (between sprag cage and outer race) should be provided. Even so, the life under such operating conditions is limited, if no hydrodynamic assistance of the sprags can be achieved.