421-20-15123 square flange pillow block bearing assembly is specially matched for Komatsu WA series wheel loaders, with 1:1 OEM matching dimensions. The whole set consists of three parts: square cast iron housing, GCr15 spherical insert bearing and eccentric locking collar. It is installed on heavy-load positions of loader chassis, travel drive and frame support. It stably buffers alternating impact loads during shoveling, climbing and long-distance transportation of loaders. The 4-bolt square flange mounting structure ensures firm installation without displacement. The complete bearing assembly can be replaced separately without disassembling transmission parts, which greatly reduces loader downtime for maintenance.

2. Material & Processing Advantages

1. Insert Bearing Core: Made of national standard GCr15 high-carbon chromium bearing steel with complete quenching and tempering heat treatment. Uniform hardness of steel balls and raceways brings excellent anti-fatigue and dust wear resistance. The spherical self-aligning structure compensates slight concentricity deviation during installation.
2. Bearing Housing: Integrally cast from high-strength gray cast iron with stress relief aging treatment, featuring high overall rigidity and impact crack resistance. Green anti-rust baking paint prevents rust under humid and muddy construction site conditions.
3. Locking & Sealing Structure: Eccentric locking collar firmly locks inner shaft by tightening to avoid loosening during operation. Double-layer rubber dust seal prevents construction silt and mine dust from entering bearing interior, avoiding steel ball jamming and premature wear failure.

3. Precision Grade Selection Guide

• P0: Standard general precision with high cost performance, suitable for daily shoveling and regular maintenance replacement of loaders in sand and stone plants and construction sites
• P6: Tighter raceway dimensional tolerance reduces running vibration and heat generation, ideal for mining fleets with 24-hour non-stop heavy-duty operation
• P5: High-precision grade for complete loader overhaul and travel transmission performance upgrade, with greatly improved running concentricity and stability

4. Quality & Installation Instruction

421-20-15123 flange pillow block bearing is strictly manufactured according to Komatsu OEM drawing parameters. The complete assembly can be directly installed on loader mounting positions without extra accessories. Every finished product passes full inspection on bearing hardness, internal clearance, housing dimension and sealing performance before delivery. Custom P0/P6/P5 precision grades are available for bulk orders. Installation steps: 1. Clean loader mounting base and drive shaft; 2. Fit bearing assembly onto shaft and align 4 flange bolt holes; 3. Insert bolts and fasten evenly; 4. Rotate eccentric locking collar to lock bearing inner ring; 5. Fill lubricating grease to finish assembly.

5. Application Scenarios

Widely applied to chassis repair of Komatsu WA400-5, WA420-5, WA430-6, WA470-6, WA480-6 wheel loaders, export wholesale of Komatsu construction machinery spare parts, and regular maintenance of fleets in sand mines and infrastructure projects. It solves common failures of original bearings such as abnormal running noise, loose eccentric collar, silt ingress caused by seal failure, bearing pitting wear and weak travel shake. The complete pillow block bearing assembly is easy to replace and effectively reduces equipment downtime losses.