Deck Extensions and Ballast Box

TRUCK FRAME

The truck frame is a stress relieved welded cellular box structure which utilizes impact resistant steel in the major load carrying members. The low temperature toughness of the steel assures adequate strength and durability across a wide range of temperatures frequently encountered in machine applications. A fabricated support structure welded integrally into the truck frame supports the center pintle hub area.

The inner diameter of the hub is machined to accept the center pintle bushing. Truck frame surfaces which mate to crawler side frames and swing rack are shop machined to assure proper alignment and solid foundation.

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 a 4-piece gear bolted to the truck frame.

Swing Rack and Roller Circle

ROLLER CIRCLE

The roller circle is composed of the upper rails, lower rails, thrust rails, 50 tapered rollers and inner/ outer roller cages. The lower rail segments are secured to the top surface of the swing rack forming a continuous rolling path for the rollers. The upper rails are attached 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.

Roller Circle Assembly