Sugar Mill Bronze Bearings Application Guide

LBC-3 Material Selection, Centrifugal Casting Process & Top Roller Bearing Design

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1. Application Background: Milling Tandem System

In the Sugar Industry, the core mechanical unit is the Milling Tandem , where multiple rollers crush sugarcane under continuous heavy load.

Key Component

• Top Roller Bottom Bearing
• Also includes:
  • Top Roller Bearing
  • Lower Top Roller Bearing

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Operating Conditions (Engineering Reality)

（extreme-duty plain bearing application）

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2. Bearing Structure & Design Selection

2.1 Structural Types Used

(1) Plain Bearing / Bushing

• Direct sliding contact
• Suitable for heavy load

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(2) Flanged Bearing

• Provides axial positioning
• Improves assembly stability

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(3) Split Bearing

• Two-piece structure
• Enables:
  • Easier installation
  • Faster maintenance

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Practical Design Combination

In sugar mills, the typical solution is:

Split + Flanged Bronze Bearing

This configuration ensures:

• Load distribution stability
• Reduced downtime
• Adaptability to large shaft sizes (e.g., Ø533 mm)

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3. Material Selection: Why LBC-3 (JIS H5121)

3.1 Material Definition

• Lead Bronze Casting LBC-3
• Equivalent to:
  • ASTM B505 C93700

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3.2 Metallurgical Mechanism

LBC-3 is a multi-phase bearing alloy:

• Cu-Sn matrix (hard phase)
  （load bearing）
• Pb phase (soft phase)
  →（self-lubrication & embedability）

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3.3 Performance Advantages

Anti-Seizure

• Prevents metal adhesion under heavy load

Debris Tolerance

• Absorbs sugar fiber and particles

Conformability

• Adapts to shaft misalignment

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3.4 Application Fit

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3.5 Limitation Awareness

• Not suitable for:
  • High-speed operation
  • Lead-restricted environments (需注意环保法规)

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4. Casting Process: Why Centrifugal Casting

4.1 Client Requirement

Preferred: Centrifugal Casting（离心铸造）

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4.2 Process Mechanism

Molten bronze is poured into a rotating mold, generating centrifugal force that:

• Compacts the metal
• Expels gas and inclusions inward
• Forms a dense outer structure

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4.3 Technical Benefits

1. High Density Structure

• Eliminates shrinkage cavities

2. Low Porosity

• Critical for heavy-duty reliability

3. Uniform Microstructure

• Better Pb distribution → stable lubrication

4. Improved Mechanical Integrity

• Especially important for large diameters (>500 mm)

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4.4 Comparison with Sand Casting

👉 Conclusion:

Centrifugal casting is function-driven, not just process preference.

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5. Machining & Functional Features

5.1 Delivery Condition

• Fully Machined Bronze Bearing

Includes:

• ID (shaft contact surface)
• OD (housing fit)
• End faces

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5.2 Functional Machining

Threaded holes:

• NPT 1/2
• NPT 3/8
• M16 × 2

Functions:

• Lubrication ports
• Fixing / alignment

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5.3 Surface Engineering

• Controlled roughness (Ra)
• Supports:
  • Oil film formation
  • Wear reduction

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6. Specific Application: Top Roller Bearing

6.1 Geometry Reference

• Journal size:
  • Ø533 × 659L mm

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6.2 Functional Role

• Supports upper crushing roller
• Transfers load to housing
• Maintains alignment

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6.3 Design Considerations

Clearance Design

• Must accommodate:
  • Thermal expansion
  • Contamination ingress

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Wall Thickness

• Thick wall → improved load distribution

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Lubrication Interface

• Integrated threaded ports

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7. Reliability & Quality Control

7.1 Required Documentation

• Chemical Composition Report
• Dimensional Inspection Report
• Material Certificate

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7.2 Recommended Enhancements

• Ultrasonic Testing (UT)
• Dye Penetrant Testing (PT)

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7.3 Critical Control Points

• Lead segregation control
• Casting cooling rate
• Machining precision (especially large ID)

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8. Engineering Insight: Why This Solution Works

The performance of sugar mill bearings is not determined by a single factor, but by the interaction of three variables:

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1. Material

• LBC-3 → anti-seizure + contamination tolerance

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2. Process

• Centrifugal casting → structural integrity

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3. Design

• Split + flanged → maintainability & stability

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👉 Integrated Result:

• Reduced failure risk
• Extended service life
• Lower maintenance downtime

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9. Conclusion

For Sugar Industry Milling Tandem applications, the combination of:

• LBC-3 Lead Bronze (JIS H5121 / ASTM B505 C93700)
• Centrifugal Casting Process
• Split / Flanged Plain Bearing Design

provides a technically aligned solution for:

• Heavy load تحمل
• Contaminated environments
• Low-speed operation

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• sugar mill bronze bearing
• LBC-3 bronze bushing
• centrifugal cast bronze bearing
• top roller bearing sugar industry
• heavy duty plain bearing
• C93700 bronze bush

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