KOMATSU 21N3000131 / 21N3000130 / KM2419 PC1250 Track Upper Roller Group | Heavy-Duty Undercarriage Parts | HE LI CQCTRACK

OEM-grade KOMATSU PC1250 upper track roller assembly (P/N :21N3000131, 21N3000130, KM2419). Manufactured by HE LI CQCTRACK for exceptional durability in extreme-duty mining and excavation applications. Source directly from a specialized supplier.

Content:

Engineering the Support System: The Upper Roller Group in Ultra-Class Excavators

For ultra-class excavators like the KOMATSU PC1250, the undercarriage is a marvel of endurance engineering, tasked with supporting over 100 metric tons of operating weight while navigating punishing terrain. The Upper Track Roller Group (Carrier Roller Group) is a fundamental component within this system. Positioned along the top of the track frame, these rollers perform the critical dual function of supporting the track’s return run and maintaining precise track tension (sag). Their performance directly dictates track chain alignment, reduces parasitic drag, and protects other undercarriage components from undue stress. In mining and large-scale earthmoving, the failure of a single upper roller can lead to catastrophic track derailment and significant downtime.

Technical Product Profile: KOMATSU PC1250 Upper Roller Assembly

This assembly is engineered as a precise, bolt-for-bolt replacement for the OEM carrier rollers on the KOMATSU PC1250 series, ensuring seamless integration and performance.

• OEM Part Number Cross-Reference: 21N3000131, 21N3000130, KM2419.
• Primary Application: KOMATSU PC1250-6, PC1250-7, and similar ultra-class hydraulic excavators.
• Component Type: Heavy-Duty Upper Track Roller (Carrier Roller) Complete Assembly.
• Design Function: To bear the weight of the upper track chain, guide its return path with minimal friction, and maintain optimal track tension for stable machine operation and extended undercarriage life.

HE LI CQCTRACK: A Source Manufacturer for Critical Undercarriage Components

HE LI (CQCTRACK) operates as a direct manufacturer and supplier, specializing in the complete production cycle of heavy-duty undercarriage parts. Their capability to produce the PC1250 Upper Roller Group stems from a vertically integrated manufacturing philosophy focused on extreme-duty applications.

Manufacturing Process & Quality Engineering:

1. Forging for Structural Integrity:
   • The roller body originates as a forging from specially selected high-tensile, low-alloy steel. The forging process aligns the metallic grain structure to the part’s shape, creating superior impact strength and fatigue resistance—a non-negotiable requirement for the dynamic and shock loads experienced by a PC1250.
2. Precision Machining & Surface Engineering:
   • Post-forging, the component undergoes rigorous CNC machining to achieve exacting tolerances for the outer diameter, flange width, and internal bore. This precision ensures perfect concentricity for smooth rolling and a flawless fit with the track frame brackets and internal bearing systems.
   • The roller’s running surface and, critically, the guiding flanges are subjected to computer-controlled induction hardening. This creates a deep, consistent case hardness (typically 58-62 HRC) on the contact surfaces, providing exceptional resistance to abrasive wear from the track bushing and lateral grinding against the track chain links.
3. Sealed & Lubricated Bearing Chamber:
   • The internal bearing system is engineered for longevity. It incorporates a multi-passage labyrinth seal design working in tandem with heavy-duty floating face seals. This combination is pressure-tested to prevent the ingress of abrasive contaminants (fine ore dust, slurry, silica) and retain high-performance lithium-complex grease, ensuring consistent lubrication under all operating temperatures and conditions.
4. Complete Assembly Integration:
   • HE LI supplies the unit as a complete, ready-to-install assembly. This includes the hardened roller body, high-capacity tapered roller bearings or bushings, the sealed internal cavity pre-filled with grease, the hardened steel shaft, seals, and all necessary fasteners. This eliminates guesswork during maintenance and reduces machine downtime.

Why Source from a Dedicated Manufacturer like HE LI CQCTRACK?

For equipment owners and procurement specialists managing ultra-class fleets, sourcing from a dedicated manufacturer offers distinct advantages:

• Control Over Quality & Specification: Direct manufacturing allows for stringent control at every stage, from material metallurgy to final assembly, ensuring the part meets the exact performance demands of a PC1250.
• Focus on Heavy-Duty Applications: HE LI CQCTRACK‘s process is tailored for mining and severe-service parts, not generalized industrial components. This focus is evident in material choices and hardening protocols.
• Supply Chain Stability & Traceability: As a manufacturer, they provide greater supply chain reliability and full traceability of the production lot, which is crucial for maintenance planning and warranty support.
• Cost-Effectiveness without Compromise: Eliminating intermediary layers allows for providing a component that matches OEM performance specifications at a more competitive total cost of ownership, driven by durability and reduced failure rates.

Operational & Maintenance Insight

• Paired Inspection: Upper rollers should be inspected in conjunction with track chains and lower rollers. Irregular wear patterns on the roller flanges or running surface often indicate track misalignment or improper tension.
• Preventative Replacement: Proactive, group-based replacement of upper rollers as part of a planned undercarriage maintenance schedule is more cost-effective than reactive replacement after a failure, which risks collateral damage.

Conclusion

The KOMATSU 21N3000131 / 21N3000130 / KM2419 Upper Track Roller Group is a precision-engineered component where failure is not an option. HE LI CQCTRACK positions itself as a capable source manufacturer for these critical parts, leveraging material science, advanced manufacturing, and a deep understanding of severe-service undercarriage dynamics. For fleet managers operating PC1250-class excavators in demanding environments, partnering with such a specialized supplier provides a viable strategy for maximizing equipment availability, optimizing maintenance budgets, and ensuring uncompromised operational safety and productivity.