A rotating assembly for a machine is disclosed herein. The rotating assembly includes an annular support structure and a shaft assembly. The annular support structure includes a bore therethrough and protrusion extending helically around a portion of the bore. The shaft assembly includes a shaft and a collar coupled to the shaft. The collar includes a plurality of grooves located at the outer surface of the collar. The collar is positioned within the bore of the annular support structure such that the plurality of grooves are adjacent to the protrusion. As the annular support structure rotates, the protrusion rotates and is configured to move debris and mud out of the rotating assembly.