The drum 1 is driven to rotate at a constant speed in {HEAD ~ the direction} indicated by the arrow by means of a main motor 2 through {TAIL ~ a power transmission mechanism}  
The drum 1 is driven to rotate at a constant speed in { HEAD ~ the direction } indicated by the arrow by means of a main motor 2 through { TAIL ~ a power transmission mechanism }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH