Err no, the pulley which is mounted to the engine has the drive belts on it which in turn drive the upper pulley.
That upper pulley when it starts to spin as the belts tighten -with the clutch ( a linear actuator that tightens the belts by pushing the upper pulley upwards) - drives the sprag clutch at its inner self, which in turn drive the shaft inside it and it goes into the transmission, forward and the tail rotor rearward.
As the sprag is a free wheel in one direction, so, when the engine /lower pulley / upper pulley, stops then the inner shaft just keeps on rotating in the same direction as a free wheel, allowing a nice autorotaion.
The linear actuator has a bearing at each end so the shaft at each end (the inner shaft at the upper end and the engine drive shaft at the lower end) can spin and still keep a preset tension on the actuator for belt tension. The clutch light goes out when it has engaged to a preset tension which is reached by a special spring mechanism.
See quite simple.