High Leaded Tin Bronze Alloys For Bearing Bushes: Codes And Specifications

Here are some material codes and specifications commonly used for bearing bushes:

• CDA 932 (SAE 660, C93200):
  This alloy is a standard material for light-duty applications, valued for its strength, machinability, and resistance to corrosion from seawater and brine. It contains 81-85% copper, 6.3-7.5% tin, 6-8% lead, 1-4% zinc, 1% nickel, and trace amounts of antimony and iron. It is suitable for automotive fittings, bearings, bushings, gears, impellers, and washers, meeting ASTM B505, ASTM B271, SAE J461, and SAE J462 standards.
• C93600 (Modified SAE 64 Bronze):
  Used in bushings for corrosion, lubrication, or pressure applications, this alloy contains 79-83% copper, 11-13% lead, and 6-8% tin. It is available in various sizes and can be custom-made to fit specific needs.
• C93200:
  Known for its strength, hardness, and shock resistance, C93200 is popular for heavily loaded, lubricated, and true-running bearings. It complies with SAE 660, SAE J461/J462, and ASTM B505 standards.
• C93700 Alloy (“Bearing Bronze”):
  This high-strength, leaded bronze alloy is designed for applications requiring durability and wear resistance.

Choosing the Right High Leaded Tin Bronze Alloy
When selecting a high leaded tin bronze alloy for bearing bushes, consider the application requirements, including load capacity, speed, and environmental conditions. Each of these materials has specific properties that make them suitable for particular uses. Consulting a technical expert or supplier will help ensure that the chosen material meets the necessary specifications.

Leaded tin bronze bearings, such as those made from CuPb15Sn8 alloy, are a common choice for heavy-duty applications like a cylinder hydraulic crusher due to their excellent wear resistance, ability to withstand high loads, and good conformity and embeddability.

Key Properties of CuPb15Sn8 Alloy:

• Composition: Typically contains approximately 15% lead, 8% tin, and the remainder copper. This combination provides both strength and the ability to absorb minor impurities and distribute them without damaging the cylinder surfaces.
• Hardness and Strength: The alloy is moderately hard, which helps it resist surface wear and deformation under heavy loads.
• Conformity and Embeddability: The lead in the alloy allows it to conform to slight misalignments and irregularities in the shaft, and also helps in embedding small particles, which might otherwise cause damage.
• Corrosion Resistance: While not the primary feature, it does offer reasonable resistance to corrosion, particularly from the lubricants and other fluids in hydraulic systems.
• Fatigue Resistance: Good fatigue resistance is crucial for bearings that experience high cyclic loads as seen in hydraulic crushers.

Material 

CuPb15Sn8

Applications:

• Hydraulic Crushers: In the cylinders of these crushers, bearings need to absorb significant radial and occasionally axial loads while providing smooth movements.
• Heavy Machinery: Apart from crushers, this bearing material is suitable for other heavy machinery in mining, construction, and industrial applications where similar loads are encountered.

Design Considerations:

When designing or selecting a leaded tin bronze bearing for use in a hydraulic crusher, consider the following:

• Load and Speed: Ensure the bearing material’s load capacity and speed limits align with the operational conditions of the crusher.
• Environment: Consider the environmental conditions such as temperature, presence of abrasive particles, and exposure to corrosive fluids.
• Lubrication: Adequate lubrication is crucial. The design should ensure easy access for regular lubrication to maintain the bearing’s performance and longevity.

High lead bronze bushings, particularly those made from the CuPb15Sn8 alloy, are exceptionally well-suited for demanding sectors like mining and heavy machinery. These components are critical in settings that subject them to severe mechanical stress due to their superior wear resistance, inherent self-lubricating features, and robust build, ensuring both efficient and dependable operations.

Applications of High Lead Bronze Bushings:

• Mining Industry: High lead bronze bushings play crucial roles in the mining sector, where they are extensively used in crushers, excavators, and other heavy equipment. They help to reduce friction and wear between moving parts, significantly enhancing both durability and operational efficiency.

• Crushers: These bushings are vital in several crusher components:

  • Shaft and Eccentric Bushings: They aid in the controlled movement of the crusher’s main shaft, facilitating its rotation and oscillation to effectively crush materials.
  • Friction Discs: Utilized in creating middle friction discs, as well as upper and lower friction discs, high lead bronze is chosen for its ability to withstand high loads and resist wear.

• Cone Crushers: In cone crushers, these bushings are indispensable as eccentric bushings that support the gyratory movement of the crusher’s main shaft, crucial for the crushing process and ensuring smooth operation and alignment of the crushing head or mantle.

Advantages:

• Wear Resistance: Offers outstanding wear and abrasion resistance, critical for the longevity of components in abrasive environments.
• Self-Lubrication: The alloy’s lead content naturally reduces the need for frequent maintenance, enhancing machinery efficiency.
• Corrosion Resistance: Provides reasonable resistance to corrosion, suitable for harsh conditions typical in mining and maritime settings.

Maintenance and Care:

• Regular Inspection: Continuous and efficient operation requires regular checks for wear and damage.
• Adequate Lubrication: While inherently self-lubricating, some applications may require additional lubrication depending on specific conditions.

Overall, the high lead bronze bushings crafted from CuPb15Sn8 alloy are vital in heavy-duty applications, where their mechanical attributes greatly boost the performance and durability of essential machinery components.

Maintenance Tips:

• Regular Inspection: Frequent inspection for wear and damage can prevent sudden machinery failures.
• Lubrication: Maintaining proper lubrication reduces friction and wear, and helps in dissipating heat generated by the operation.
• Cleanliness: Keeping the bearing and its environment clean prevents the ingress of abrasive particles that can accelerate wear.

Leaded tin bronze bearings made from CuPb15Sn8 are a robust choice for applications like hydraulic crushers, ensuring durable and reliable performance under challenging conditions.