Patent ID: 8500208

Claim:
A coal cutter drum assembly, comprising: a cutter drum having an inner diameter and mounted for rotation about a cutter drum shaft; multiple bit retainers secured to an external surface of the cutter drum; multiple cutting bits, each such cutting bit being received in one of the multiple bit retainers; a first bit and bearing retainer subassembly joined to the cutter drum at one end of the cutter drum and further joined to a first sprocket that is used to rotate the cutter drum; a first bearing supporting the cutter drum, said first bearing being positioned in the first bit and bearing retainer subassembly, and said first bearing having an outer diameter that exceeds the inner diameter of the cutter drum; a second bit and bearing retainer subassembly joined to the cutter drum at an opposite end of the cutter drum and further joined to a second sprocket that is used to rotate the cutter drum; and a second bearing supporting the cutter drum, said second bearing being positioned in the second bit and bearing retainer subassembly, and said second bearing having an outer diameter that exceeds the inner diameter of the cutter drum.