Wear Analysis of the Traveling Mechanism of Crawler Bulldozers and Countermeasures to Extend its Service Life

The traveling mechanism of the crawler bulldozer (Figure 1) bears the entire weight of the bulldozer and is responsible for its driving function. The main form of damage is wear, which is mainly manifested in the following contact parts: the teeth of the drive wheel and the outer surface of the track pin sleeve; the guide wheel and the raceway surface of the track link. The raceway surface of the idler wheel and the track link; The raceway surface of the idler wheel and the track link; Contact surface between the track pin and the pin sleeve; The track plate and the ground, etc.

1. Wear and tear of the tracks

In the walking mechanism of dry tracks (as well as lubricated tracks and sealed tracks), the tracks are not lubricated, which causes wear between the track pins and pin sleeves due to relative movement during operation. The wear of the pins and pin sleeves in the track is inevitable and normal, but this kind of wear will cause the pitch of the track to elongate, making the track too large. If this wear continues, the track will shift sideways, causing wear on components such as the guide wheels, idler wheels, idler wheels, and drive wheel teeth, and also exacerbating the wear on the track pins and sleeves.

The wear of the tracks is also manifested in the reduction of the height of the track spikes due to the contact between the track plates and the ground, as well as the reduction of the height of the track links caused by the contact between the raceway surfaces of the track links and the guide wheels, idler wheels and support wheels. When the track plates are severely worn, it will cause a loss of the bulldozer's traction force.

2 Wear of the driving wheels

Wear of the drive wheel teeth often occurs at the root of the teeth, the front and rear sides, the left and right sides, and the top of the teeth. When the bulldozer moves forward and the gear teeth lift the track pin sleeve, wear occurs on the front side of the gear teeth. Conversely, when the bulldozer moves backward, wear occurs on the rear side of the gear teeth. When the track is too loose, causing the track to be skewed and the gear teeth to impact the side of the track link, it will lead to wear on the side of the drive wheel gear teeth.

Another form of wear for the teeth of the drive wheel is top wear. Top wear occurs when the track and the teeth of the drive wheel are filled with sticky substances, and the meshing relationship between the teeth of the drive wheel and the track pin sleeve is changed. When the bulldozer moves forward, it will leave marks on the top of the back of the teeth on the drive side of the drive wheel and the side of the pin sleeve.

3 Wear of the guide wheel

The wear of the guide wheel is caused by the raceway surface in contact with the track link, while the wear of the protruding width of the guide wheel body is due to the contact with the side of the track link. It is manifested as: the reduction of the protruding width of the guide wheel body; Reduction of the diameter of the raceway surface of the guide wheel body; The reduction of the diameter of the guide wheel body

4 Wear of the idler wheel

The wear of the idler wheel is caused by the raceway surface in contact with the track link. It is manifested as: the reduction of the flange width of the idler wheel; The reduction of the outer diameter of the raceway surface of the idler wheel; The reduction of the outer diameter of the flange of the idler wheel.

5 Wear of the idler wheels

The wear of the idler wheel, like that of the idler wheel and the guide wheel, is also caused by the contact with the raceway surface of the track link. Specifically, it is manifested as: the reduction of the diameter of the outer flange; The reduction of the raceway surface diameter; Reduction of the diameter of the bilateral inner flanges; The reduction of the width of the bilateral inner flanges; The reduction of the width of the outer flange.

The following measures can be taken to address the wear of the crawler-type walking mechanism:

(1) If the traveling mechanism of the bulldozer shows obvious wear in the early stage, the operation should be stopped immediately and the overlap degree between the centers of the guide wheels, idler wheels, support wheels and drive wheels and the longitudinal center line of the traveling frame should be checked.

(2) To extend the service life, the positions of the front and rear idler wheels can be swapped, but the original positions of the single and double idler wheels on the walking frame must remain unchanged.

(3) When the components of the traveling mechanism wear to the service limit, the guide wheels, idler wheels, support wheels, drive wheel teeth, track spikes and track links can all be repaired or replaced by surfacing welding.

(4) In cases where the track link pitch becomes longer due to wear, measures such as reversing the track link or replacing it with a new one can be taken to remedy the situation.