The causes of damage to bulldozer track rollers primarily include the following aspects:

Material and Heat Treatment Issues: The selection of materials and heat treatment processes for track rollers significantly impacts their performance. For example, high-power bulldozer track rollers may develop batch inner bore cracks after overall heat treatment due to the absence of normalization post-forging. This results in mixed grain sizes in the forged structure, and insufficient tempering time post-heat treatment prevents complete transformation of martensite to tempered martensite.

Seal Failure: Improper design or manufacturing of the sealing structure of track rollers can lead to oil leakage. For instance, oil leakage in track roller assemblies is mainly due to poor lubrication between the contact surfaces of the two floating seal rings, and inadequate machining quality and assembly quality of parts related to the seal.

Wear and Fatigue: Track rollers are subjected to wear and fatigue over prolonged use, especially in harsh working environments. Common wear in tracked bulldozers' "four wheels and a belt" is observed at the contact points between the track roller and the track chain rail. Additionally, fatigue wear of track rollers in tunneling machines is also a significant form of damage.

Structural Design Issues: Unreasonable structural design can also lead to early failure of track rollers. For example, the original track roller shaft of the SD13 bulldozer was a plain shaft, relying solely on small diameter circlips on both sides to bear axial force. This led to increased assembly gaps and insufficient pressure of the large diameter O-ring on the floating oil seal ring, causing oil leakage.

Improper Operation and Maintenance: Improper operation and maintenance are also crucial factors contributing to track roller damage. For instance, the wear mechanisms of the walking mechanism of large track bulldozers are explored from the perspectives of operation and maintenance.

In conclusion, the causes of bulldozer track roller damage are diverse, including material and heat treatment issues, seal failure, wear and fatigue, structural design problems, and improper operation and maintenance. To address these causes, appropriate improvement measures should be taken, such as optimizing material and heat treatment processes, improving seal design, and enhancing daily maintenance and inspections, to improve the service life and reliability of track rollers.

Reference:

https://www.semanticscholar.org/paper/Identifying-root-causes-of-heavy-haul-wheel-damage-Ekberg-Kabo/4d4755a86185c5cf502c17876a2f335d4cce9ad1