TRACK FRAME

The track frame, as the name implies, serves as a framework and support for the track assembly, rollers, front idler, recoil spring, and adjusting mechanism.

Track frame alignment may be fixed or shim adjusted depending on the manufacturer. When shims are used, there are a couple of ways alignment may be maintained. One way is using shims where the frame attaches to the rear pivot and also near the center of the track frame where it is mounted against the main frame guide brackets. Another way is to use a diagonal brace and shims at the rear pivot to align the track frame.

Track Frame Rollers

Two types of track frame rollers are used on tracked equipment - those located on the lower portion of the track frame which supports the weight of the tractor, and those above the track frame which supports the track assembly, as it passes over the track frame.

Carrier rollers (fig. 6-24) are single-flanged rollers mounted on brackets, which extend above the track frame and supports the track assembly. Two of these rollers are on each side of the tractor. The flange extends upward between the links of the track chain. keeping the chain in alignment between the drive sprocket and the front idler.

Track rollers (fig. 6-25) are double- and single- flanged rollers that supports the weight of the tractor, ensures that the track chain is aligned with the track frame at it passes under the rollers, and prevents side to side track movement and derailment. In a normal arrangement, a double- flanged roller is directly in front of the drive sprocket, followed by a single-flanged roller. The rollers alternate forward to the front idler.

The front idler, as shown in figure 6-25, serves as a guiding support for the track chain. The idler is spring- loaded and mounted on slides or guides that allow it to move back and forth inside the track frame, as the tractor passes over uneven terrain. The spring loading

Figure 6-25. - Track rollers in position in the track frame.

Figure 6-24. - Track carrier rollers.