SDLG E6730H Track Btottom Roller Assembly/Heavy duty crawler undercarriages Made by DPW PARTS/Source Manufacture and factory
Product Specifications
Professional Overview: SDLG E6730H Track Roller Assembly (Undercarriage)
The Track Roller Assembly, a core component of the undercarriage system on the SDLG E6730H excavator, is critical for mobility, stability, and overall machine performance. The SDLG E6730 is a large excavator, typically in the 75-ton class, designed for demanding applications in construction, quarrying, and mining.
This analysis provides a detailed breakdown of its track roller group, synthesizing standard engineering principles for undercarriages of this size and duty cycle.
1. Primary Function and Importance
The Track Roller Assembly (often called the lower track roller or bottom roller) is a key element of the entire undercarriage system. Its functions are:
Weight Support: It carries the majority of the machine's operating weight (approximately 70,000+ kg for the E6730) and rolls along the bottom of the track chain.
Load Distribution: It helps distribute the immense weight of the machine evenly across the track chain and onto the ground, contributing to low ground pressure.
Guidance and Alignment: It works in conjunction with the top rollers and idlers to keep the track chain aligned and running true on the track frame.
Shock Absorption: It absorbs impacts and shocks from uneven terrain, protecting the mainframe and internal components from excessive vibration.
A well-maintained track roller assembly is essential for smooth travel, reduced vibration, and maximizing the lifespan of the entire undercarriage system.
2. Key Components of the Track Roller Assembly
While the "assembly" can refer to the entire undercarriage, it most precisely refers to the individual roller units. However, it's crucial to understand its role within the full undercarriage system, which includes:
Track Rollers (Bottom Rollers): These are the sealed, lubricated rollers that directly support the machine's weight. They are mounted on the track frame and are subject to constant abrasion and shock loads. They typically feature:
Hardened Steel Rims: For extreme wear resistance against the track chain links.
Sealed Lubrication: Grease-filled and sealed to prevent contamination and ensure continuous lubrication of internal bearings.
Double or Triple Flanges: Common on machines of this size to provide superior track guidance and prevent derailment.
Track Frame (Beam): The main structural member that houses the rollers' axles and connects to the excavator's main body.
Track Chain (Link Assembly): Consists of links, pins, and bushings. The rollers ride on the hardened bushings of the chain.
Track Idlers (Front Idlers): The guide wheels at the front of the track frame.
Sprockets (Drive Sprockets): The final drive components that engage with the track chain to propel the machine.
Track Shoes (Pads): Bolted to the chain links, they provide traction and flotation. The E6730 likely uses shoes in the 500mm - 600mm width range for its applications.
3. Technical Specifications & Performance (Inferred for E6730 Class)
Based on the standard specifications for a 70-ton excavator like the SDLG E6730:
| Parameter | Estimated Specification | Implication |
|---|---|---|
| Shoe Width | 500 - 600 mm (e.g., 600mm) | A wide shoe reduces ground pressure, enhancing stability and enabling work on softer surfaces. |
| Ground Pressure | ~50 - 60 kPa (approx. 7 - 8.5 psi) | Low ground pressure for excellent flotation and minimal ground disturbance. |
| Number of Rollers | 7-9 per side | A higher number of rollers distributes the machine's weight more evenly, reducing point loading and wear. |
| Roller Design | Sealed and Lubricated, Double-Flanged | Standard for modern excavators, ensuring long life and reliable performance with minimal maintenance. |
4. Design, Durability, and Maintenance
The E6730's undercarriage is built for durability in tough conditions. Key features of the roller assembly include:
Robust Construction: Manufactured from high-strength, alloy steel with hardened running surfaces to withstand abrasion and impact.
Advanced Sealing: Multi-layered lip seals are used to keep grease in and contaminants (water, silt, abrasive dust) out. The integrity of these seals is the single most important factor determining the roller's service life.
Large Diameter Rollers: Larger rollers reduce rolling resistance, generate less heat, and typically have a longer lifespan than smaller rollers.
Easy Replacement: Rollers are designed to be replaced individually. They are typically mounted to the track frame with bolts or pressed onto fixed axles.
Common Failure Modes:
Seal Failure: The primary cause of roller failure. Once the seal is compromised, contaminants enter and abrasive wear destroys the internal bearings, causing the roller to seize or lock up.
Flange Wear: The guiding flanges can wear down from constant contact with the track chain, especially if track tension is incorrect.
Wear and Performance Degradation: Over time, the roller's outer surface will wear from friction with the track bushing, reducing its diameter.
Essential Maintenance Best Practices:
Daily Inspection: Walk around the machine and check for rollers that are not turning (indicating seized bearings), visible oil leaks from seals, or excessive wear on the flanges and rims.
Cleanliness: Regularly remove packed mud and debris from the undercarriage. Packed material can harden and put pressure on roller seals, leading to premature failure.
Correct Track Tension: Maintain track tension (sag) according to the operator's manual. Over-tensioning places excessive load on rollers and idlers. Under-tensioning can cause derailment and impact damage.
Proper Operation: Avoid high-speed travel on abrasive surfaces and minimize sharp, high-power turns, which cause accelerated and uneven wear on all undercarriage components, including rollers.
