Bronze Pivot Bearings for Tandem Suspension Systems

Applications in Feed Mixers, Manure Handling & Hay Equipment

In agricultural machinery, tandem suspension systems are widely used to support heavy loads while maintaining stability over uneven terrain. At the heart of these systems are pivot points, where bronze sleeve bearings (bushings) provide reliable sliding motion under high load, shock, and contamination.

This article explains the specific application locations of bronze pivot bearings in feed mixers, manure handling equipment, and hay machinery, and why bronze—especially aluminium bronze—is the preferred bearing material.

1. Feed Mixers – Tandem Axle Pivot Bearings

Typical Machines

• Vertical feed mixers

• Horizontal feed mixers

• TMR (Total Mixed Ration) wagons

• Self-propelled and trailed mixer wagons

Specific Pivot Bearing Locations

Bronze pivot bushings are installed at:

• Tandem axle equalizer beam pivot points
  (between the equalizer beam and chassis frame)

• Suspension arm to frame pivots

• Axle walking beam center pivots

• Pivot pin to hanger bracket interfaces

These pivot points allow the tandem axles to articulate independently, keeping all wheels in contact with the ground while carrying extremely heavy feed loads.

Operating Conditions

• Very high static load (fully loaded mixer wagons)

• Low-speed oscillating motion

• Frequent shock when moving over concrete, silage pits, or uneven yards

• Exposure to moisture, silage acids, and feed residues

Why Bronze Bearings Are Used

• High load-carrying capacity

• Excellent resistance to shock and fatigue

• Good corrosion resistance in wet, acidic environments

• Reliable performance with grease lubrication

2. Manure Handling Equipment – Suspension & Chassis Pivot Points

Typical Machines

• Manure spreaders

• Slurry tankers

• Manure trailers

• Compost spreaders

Specific Pivot Bearing Locations

In manure handling equipment, bronze pivot bearings are commonly found at:

• Tandem suspension walking beam pivots

• Axle-to-equalizer beam pivot joints

• Suspension hanger bracket pivots

• Chassis articulation points between axle assemblies

These bearings support heavy, uneven loads and allow controlled movement of the axle assemblies during field operation and transport.

Operating Conditions

• Extremely harsh environments

• Continuous exposure to manure, slurry, moisture, and abrasive particles

• Low-speed oscillation with high contact pressure

• Infrequent maintenance in real-world farm use

Why Bronze Bearings Are Used

• Superior wear resistance compared to steel bushings

• Better tolerance to dirt and contamination

• Reduced risk of seizure under marginal lubrication

• Long service life even with irregular greasing

3. Hay Equipment – Tandem Suspension & Articulation Pivots

Typical Machines

• Hay wagons

• Bale trailers

• Bale accumulators

• Large square and round bale transporters

Specific Pivot Bearing Locations

Bronze bushings are installed at:

• Tandem axle pivot points

• Walking beam center pivots

• Suspension arm hinge points

• Frame articulation joints on multi-axle trailers

These pivot points allow smooth axle movement when traveling over uneven fields, preventing excessive stress on the frame and axles.

Operating Conditions

• Medium to heavy loads with dynamic impact

• Repeated oscillating motion

• Dust, dirt, and crop residue contamination

• Outdoor exposure with seasonal operation

Why Bronze Bearings Are Used

• Excellent resistance to abrasive dust

• Stable friction characteristics

• Good compatibility with hardened steel pivot pins

• Simple, robust design suitable for agricultural equipment

4. Why Aluminium Bronze Pivot Bearings Are Preferred

In agricultural tandem suspension systems, aluminium bronze alloys (such as C95400 or C95500) are commonly selected due to:

• High mechanical strength

• Excellent fatigue resistance

• Superior performance under oscillating motion

• Good corrosion resistance in wet and chemically aggressive environments

When combined with proper grease groove designs (helix or figure-eight), aluminium bronze bearings significantly reduce wear and downtime.

5. Typical Bronze Pivot Bearing Design

• Bearing Type: Bronze sleeve / bushing

• Material: Aluminium bronze (C95400 / C95500)

• Application: Tandem suspension pivot points

• Motion: Oscillating / limited rotation

• Lubrication: Grease-lubricated via grease nipple

• Installation: Press-fit into suspension brackets or beams

Conclusion

In feed mixers, manure handling equipment, and hay machinery, tandem suspension pivot points operate under some of the harshest agricultural conditions. Bronze pivot bearings provide a proven, maintenance-friendly solution for these applications by offering high load capacity, excellent wear resistance, and reliable performance in contaminated environments.

From equalizer beam pivots to axle suspension arm joints, bronze bushings play a critical role in ensuring smooth operation, reduced maintenance, and extended service life of agricultural equipment.