LIUGONG 51C0249 Track Bottom Roller Assy | For CCLG936E Excavator | OEM/ODM Manufacturer – HELI(cqctrack)

High-performance Track Bottom Roller Assembly (Part# 51C0249) for the LIUGONG CCLG936E excavator. Engineered and manufactured by HELI (CQCTRACK) to exact OEM specifications, featuring forged components, advanced sealing, and optimized heat treatment for superior durability in heavy-duty undercarriage applications.

1. Product Definition & Application Criticality

The Track Bottom Roller Assembly, referenced under the OEM part number 51C0249, is a fundamental load-bearing component within the undercarriage system of the LIUGONG CCLG936E hydraulic excavator. This model represents a pivotal machine in the 30-40 ton class, widely utilized in construction, quarrying, and infrastructure projects. The Bottom Roller is subjected to continuous radial loads, abrasive wear, and impact shocks. As both an OEM-specification supplier and an ODM (Original Design Manufacturer), HELI (CQCTRACK) produces this assembly not merely as a replacement part, but as an engineered system designed to meet and exceed the rigorous demands of the CCLG936E’s operational lifecycle, ensuring optimal machine stability, travel performance, and cost-efficiency.

2. Technical Anatomy & Functional Mechanics

This assembly functions as the primary interface between the excavator’s massive weight and the track chain. Its design is a balance of brute strength and precision engineering.

• Core Function:
  • Static & Dynamic Load Support: Directly carries the machine’s operational weight, transferring it through the roller tread to the track links and shoes.
  • Track Guidance & Stability: The dual-flange design securely guides the track chain, preventing lateral slippage and derailment during turns and on uneven ground.
  • Friction Minimization: By providing a smooth, hardened rolling surface, it converts sliding friction into efficient rolling motion, reducing drive force requirements and power loss.
• Structural & Material Deconstruction (HELI Specification):
  • Wheel Body: Fabricated from high-grade, wear-resistant alloy steel (e.g., 55Mn, 50Mn). HELI employs either precision forging or centrifugal casting processes based on the performance tier, ensuring a dense, void-free microstructure with superior integrity compared to standard castings.
  • Shaft (Spindle): Manufactured from quenched and tempered alloy steel (e.g., 40Cr, 42CrMo), providing exceptional resistance to bending and shear forces. The shaft is the non-rotating backbone of the assembly, fixed directly to the machine’s track frame.
  • Bearing System: Utilizes large-diameter, tapered roller bearings. These bearings are selected for their supreme radial load capacity and ability to manage slight axial loads induced during turning. They are pre-lubricated with high-stability, extreme-pressure grease.
  • Multi-Labyrinth Seal System: The heart of longevity. HELI integrates a triple-action seal combo:
    1. Primary Nitrile Rubber Lip Seal: Provides the main elastic barrier.
    2. Grease-Purged Labyrinth Channel: Creates a positive-pressure zone to expel contaminants.
    3. Dust Wiper/Deflector: An external rigid seal to block large debris and mud.
       This system is validated for extended performance in wet and abrasive conditions.
  • End Caps & Fasteners: Robust, machined caps secure the internal components, using high-strength, grade-marked bolts for assured assembly integrity.

3. HELI’s OEM/ODM Engineering & Manufacturing Protocol

HELI’s capability as both an OEM-equivalent and ODM partner is demonstrated through a controlled, technology-driven manufacturing flow:

1. Material Science & Forming:
   • Raw material is spectrographically verified.
   • The wheel body is formed via hot forging/casting, followed by normalizing heat treatment to relieve internal stresses and refine the grain structure for optimal machinability and final toughness.
2. Precision Machining:
   • Critical surfaces—the bearing bores, seal journal diameters, and wheel tread—are machined on CNC turning centers and vertical machining centers. This guarantees concentricity, parallelism, and dimensional adherence to the original LIUGONG 51C0249 blueprint within tight tolerances (±0.03mm).
3. Advanced Surface Engineering:
   • The wheel tread and flanges undergo medium-frequency induction hardening. This process creates a controlled-depth (typically 4-6mm) hardened case with a surface hardness of HRC 58-62, while preserving a tough, shock-absorbing core (HRC ~30-35). The hardened pattern is consistent and repeatable, ensuring uniform wear.
4. Assembly & Performance Validation:
   • Clean-room assembly practices prevent contaminant ingress.
   • Each roller is tested for:
     • Smooth Rotational Torque: Ensuring no bearing binding.
     • Axial Play: Verified to be within strict non-metric specifications (e.g., <0.5mm).
     • Seal Leak Test: Subjected to air pressure decay testing to confirm seal integrity.

4. Compatibility & Service Information

• OEM Part Number: 51C0249
• Primary Machine Application: LIUGONG CCLG936E Hydraulic Excavator.
• HELI Designation: Typically cataloged under a cross-reference such as TR-LG-51C0249-HL or according to customer-specific ODM requirements.
• Service Life Factors: Service life is maximized by maintaining correct track tension, avoiding excessive lateral impacts, and regularly cleaning packed mud from around the roller flanges and seals.

5. Value Proposition & Operational Benefits

Choosing the HELI-manufactured 51C0249 Bottom Roller Assembly delivers direct operational and economic advantages:

• OEM Fit & Performance: Guaranteed direct interchangeability, restoring the CCLG936E to its original travel performance and reliability.
• Enhanced Durability: Optimized material and heat treatment protocols result in a wear life that matches or surpasses the original part, directly lowering cost-per-hour metrics.
• ODM Flexibility: HELI can work with customers on material, specification, or branding modifications, offering tailored solutions for different market segments or fleet-specific requirements.
• Supply Chain Reliability: As a dedicated manufacturer, HELI provides a stable, traceable supply chain, reducing downtime risk associated with part scarcity.

6. Conclusion: The Strategic Underpinning for a Workhorse Machine

The LIUGONG CCLG936E is a cornerstone of productivity on countless job sites. Its undercarriage, and specifically the Bottom Roller Assemblies, are foundational to its uptime and efficiency. The part number 51C0249 is therefore not just a commodity code; it represents a critical wear component that demands manufacturing excellence.

HELI (CQCTRACK), through its dual role as an OEM-spec producer and an innovative ODM partner, delivers this assembly with a depth of engineering understanding. From metallurgy to final validation, the process is designed to produce a component that provides unwavering support under load. For fleet managers and equipment owners, specifying the HELI 51C0249 equivalent is a decision that prioritizes mechanical integrity, long-term value, and sustained machine productivity, ensuring this vital excavator model remains a reliable and profitable asset.