A gear assembly that includes a cutting gear having an outer edge and an inner edge, wherein a plurality of gear teeth is formed on the outer edge thereof; and an internal gear having an outer edge and an inner edge. The internal gear further includes a plurality of gear teeth formed on the inner edge thereof, wherein the gear teeth formed on the inner edge of the internal gear are adapted to engage the gear teeth formed on the outer edge of the cutting gear; a plurality of troughs, wherein each trough in the plurality of troughs is formed between two of the gear teeth formed on the inner edge of the internal gear; and a plurality of debris discharge channels, wherein each debris discharge channel is formed at the bottommost portion of each trough and extends away from the trough toward the outer edge of the internal gear.