Case Study: Optimizing Mining Equipment Maintenance: Slew Gear Bolting Solutions for the Earth Moving Equipment Excavators
How do you optimize slew ring maintenance for coal mine excavators? By switching from impact wrenches to low-clearance hydraulic torque tools like the HYTORC STEALTH.
Project Overview
- Project Location: Mpumalanga, South Africa
- Industry: Coal Mining
- Asset: Earth Moving Equipment (EME)/Large Excavator
- Application: Slew Ring Gear Maintenance
- Primary Goal: Reduce downtime and improve bolting safety in low-clearance areas.
The Maintenance Challenge - Slew Ring Specs
- Fastener Count: 102 Bolts (Top and Bottom access)
- Fastener Size: M30
- Socket/Link Size: 46mm A/F (Across Flats)
- Torque Requirement: 1,750 Nm
- Key Constraint: Minimal clearance between bolt head and excavator superstructure.
The customer requested a solution for the tightening of the slew ring on their excavator. The requirements were to deliver an accurate, repeatable torque value. Slew rings are traditionally large diameter applications with radial bolting patterns, they are very sensitive to uneven loading causing premature bearing failures. Using the STEALTH tool ensured the desired torque value and significantly increases the component life in a safe operation. – John Fairhurst, Corporate Account Manager: Africa
The Limitations of Impact Wrenches
- Clearance Issues: Standard impact tools cannot fit between the bolt head and the excavator superstructure.
- Torque Accuracy: Impact tools provide inconsistent force, risking the structural integrity of the gear.
- Safety Hazards: High vibration increases the risk of Hand-Arm Vibration Syndrome (HAVS).
The Solution: HYTORC STEALTH
To solve the clearance problem, the team utilized the STEALTH hydraulic tool with a 46mm low-profile link.
Key Advantages
- Low-Profile Design: The 46mm link seated perfectly on every bolt, eliminating interference from the superstructure.
- Precision Torque: The hydraulic system delivered a repeatable 1,750 Nm, meeting exact OEM specifications.
- Safety First: The transition to hydraulic bolting removed the vibration risks associated with air-driven tools.
Results & Fleet-Wide Implementation
The immediate success of the repair cycle has led to a broader evaluation of tooling for the entire mining fleet, including:
- Articulated Dump Trucks (ADT)
- Tire Dozers & Wheel Loaders
- Track Dozers & Face Shovels
Ready to turn your 21-hour bolting marathons into 2-hour sprints?
Contact HYTORC for a custom Outage Efficiency Audit. Let our team show you how to eliminate heat stretching and reduce manpower requirements for your next nuclear maintenance cycle.
