The Ultimate Guide to Stacker Reclaimer Slew Bearing Replacement: A Step-by-Step Breakdown
For bulk material handling operations, the stacker reclaimer is a critical workhorse. At the heart of its slewing function lies the slew bearing—a massive component that endures tremendous radial, axial, and moment loads. When this bearing fails, it can bring your entire yard to a standstill. This comprehensive guide provides a detailed, step-by-step breakdown of the stacker reclaimer slew bearing replacement process, helping you plan for this major maintenance event with confidence.
Understanding the Slew Bearing’s Critical Role
The slew bearing enables the 360-degree rotation of the stacker or reclaimer’s boom. It acts as the pivotal connection between the upper structure (house) and the lower portal frame. A failure here directly impacts machine stability, alignment, and operational safety. Recognizing early signs of wear—such as increased noise during slewing, visible cracks or pitting, excessive backlash, or grease leakage—is crucial for proactive planning.
Pre-Replacement Planning and Safety Protocol
Successful replacement begins long before the first bolt is loosened. A detailed engineering survey is mandatory to assess the exact bearing dimensions, bolt patterns, and load specifications. Simultaneously, a comprehensive maintenance and safety plan must be developed. This includes securing the worksite, implementing lockout-tagout (LOTO) procedures, and ensuring all personnel are trained for heavy lifting and working at heights. All necessary tools, cranes, and the Stacker Reclaimer Slew Bearing Replacement kit must be on-site and inspected.
A Step-by-Step Breakdown of the Replacement Procedure
The actual replacement is a methodical, multi-stage operation requiring precision and expertise.
Step 1: Upper Structure Support and Disassembly
The first critical step is to securely support the entire upper structure (house) using synchronized hydraulic jacks or purpose-built supports. Once stable, the slewing pinion drive motors and gearboxes are disconnected. All electrical, hydraulic, and lubrication lines connected across the bearing plane are carefully detached and labeled.
Step 2: Bearing Unbolting and Removal
Workers then systematically remove the slew bearing’s inner and outer ring mounting bolts. Specialized hydraulic bolt tensioners are often required due to the immense pre-load. Using the main crane, the old, damaged bearing is carefully lifted and transported away from the worksite. This is an ideal time to thoroughly clean and inspect the mounting surfaces on both the upper and lower structures for corrosion or damage.
Step 3: New Bearing Installation and Alignment
The new, pre-greased bearing is lifted into position with extreme care. Precise alignment and levelling are paramount; even minor misalignment can drastically reduce bearing life. Laser alignment tools are used to ensure perfect concentricity and flatness before the first bolt is installed.
Step 4: Re-bolting, Reconnection, and Testing
Following the manufacturer’s specified sequence and torque/pretension values, all new high-strength bolts are installed. The pinion drives, along with all electrical and fluid lines, are reconnected. After a thorough visual inspection, the upper structure is slowly lowered onto the new bearing. The final phase involves controlled, incremental slewing
