Stieber RSCI Overrunning/ Backstopping Clutch for Bucket Wheel Excavator
A major European mine equipment manufacturer required a backstopping clutch for a bucket wheel excavator used at an open pit coal mine. The continuously rotating bucket wheel removes overburden which is transferred to an onboard inclined discharge conveyor that dumps the material onto an overland conveyor for further transport to an overburden spreader.
A Stieber Model RSCI 260 clutch, with a torque capacity of 47,970 lb.ft. (65,000 Nm), was selected to meet the requirements of this challenging application. Model RSCI is an external bearing-supported, centrifugal throwout (C/T) sprag type overrunning clutch with a rotating inner race. The primary advantage of the centrifugal throwout sprag retainer is that when the sprags lift off the outer race, there is no rubbing contact in the clutch. Therefore, the life of the clutch is determined by the life of the bearings.
Designed primarily as a backstop, the RSCI also can be used as an overrunning clutch in creep drives, where the overrunning speed is high, but the driving speed is low.