Swing Rack and Roller Circle

SWING RACK

The swing rack is a large diameter external tooth gear mounted on the top of the truck frame concentric with the center pintle bore. The rack is constructed of a one-piece forged steel rim welded to a cast support core and welded to the truck frame during erection.

Swing Rack and Roller Circle

ROLLER CIRCLE

The roller circle is comprised of upper and lower rails, 56 tapered rollers and inner/outer roller frames. Lower rail segments are secured to the top surface of the swing rack forming a continuous rolling path for the rollers. Upper rails attach to the bottom of the revolving frame, fore and aft of the center pintle. Upper rail ends are tapered to provide a smooth approach for the rollers. Rollers are tapered to ensure non-skid contact with rails. The rollers are spaced and aligned with pins and low maintenance polyurethane bushings.