Trunnion Bearing
Heavy-Duty Rotation Support. Precision Alignment. Built for Bulk Handling Systems.
Trunnion bearings are specialized load-bearing components designed to support and allow rotation of large, heavy cylindrical drums or vessels. Found primarily in ball mills, rotary kilns, and industrial dryers, these bearings manage massive radial loads while ensuring the smooth rotation of the trunnion-mounted equipment.
Engineered for strength, reliability, and service longevity, trunnion bearings are integral to equipment operating under extreme conditions—be it high temperatures, heavy axial forces, or long operational cycles. Their rugged design, hydrodynamic lubrication, and vibration-damping construction make them indispensable in cement, mining, power, and metallurgical plants.
Application:
Trunnion Bearing Applications Across Industries
Trunnion bearings are essential in bulk material handling and rotary processing systems, where rotation under load must be smooth and stable.
| Industry | Applications |
| Cement Plants | Rotary kilns, clinker coolers, horizontal mills |
| Mining & Minerals | Ball mills, SAG mills, crushers |
| Power Generation | Coal pulverizers, dryers, biomass rotary units |
| Fertilizer & Chemicals | Rotary granulators, mixers, and reactors |
| Metallurgical Plants | Smelting furnaces, annealing drums |
What Is a Trunnion Bearing?
A trunnion bearing is a support unit that enables a rotating drum, mill, or shell to turn smoothly around its axis. Mounted on either end of a rotating cylinder (or ‘trunnion’), it distributes the weight of the structure while permitting free rotation. These bearings are typically housed in heavy-duty cast steel or cast iron housings and are lined with white metal or bronze-based bearing materials.
A trunnion bearing assembly includes:
- Trunnion Shaft (Journal Surface) – Machined surface rotating inside the bearing
- Bearing Insert (Liner/Bush) – Made of white metal, bronze, or bimetal alloys
- Pedestal Housing – Provides structural support and alignment
- Sealing System – Prevents ingress of dust, slurry, or moisture
- Lubrication Arrangement – Forced oil or oil bath system ensures hydrodynamic film formation
Proper alignment, material compatibility, and thermal expansion accommodation are key to its long-term performance.
Materials That Withstand the Pressure
Each component is manufactured using durable, high-grade materials selected to withstand abrasive loads, high heat, and continuous operation.
| Component | Material / Characteristics |
| Trunnion Journal | Forged steel or alloy steel – High strength, wear resistance |
| Bearing Liner | White Metal (Babbitt), Bronze, or Bimetal – Conformability, shock absorption |
| Housing | Cast Iron, SG Iron, or Cast Steel – Withstands load, impact, and misalignment |
| Seals & Gaskets | Labyrinth, Rubber, or Custom – Dust and fluid ingress protection |
RoHS-compliant and lead-free bearing materials are available for environmentally regulated industries.
Our Product Range Includes:
- Trunnion Bearings for Ball Mills and SAG Mills
- Rotary Kiln Trunnion Bearings
- Custom-Fit Trunnion Bushings and Housings
- Split and Solid Housing Options
- Sealed and Open-End Designs Based on Environment
- Reverse-Engineered Replacement Units for Legacy Systems
Reverse Engineering & Custom Manufacturing
When dealing with older mills or imported equipment lacking data, trunnion bearings can be fully reverse-engineered to create exact-fit, performance-improved replacements.
Capabilities include:
- Shaft/trunnion diameters from 150 mm to 1200 mm+
- Liner and bushing re-creation based on wear analysis
- Customized housings to match mountings and thermal expansion
- Material upgrades for corrosive, abrasive, or high-heat conditions
- On-site measurement, CAD modeling, and fast-track prototyping
Each replacement unit is tested for fit, function, and endurance.
Why Choose Trunnion Bearings?
- Supports Massive Loads: Ideal for rotating systems with heavy axial and radial pressure
- Smooth Hydrodynamic Lubrication: Reduces friction and enhances service life
- High Misalignment Tolerance: Pad and liner systems accommodate minor shaft movement
- Thermal & Shock Resistance: Maintains integrity under fluctuating operational stresses
- Long-Term Service: Minimal maintenance with robust sealing and material options
Why Partner with Metatek Engineering?
- Application-based design for rotary systems across sectors
- In-house casting, machining, and metallurgy facilities
- Expertise in replacement of OEM and outdated components
- DIN and ISO standards compliance
- Fast response for custom design, manufacturing, and MRO supply
Need a heavy-duty bearing that rotates with power and precision?
Trunnion Bearings by Metatek Engineering are built to carry the load—no matter how extreme the environment.