If you’ve ever looked at a hydraulic cylinder and wondered why it has those two side pivots near the middle, chances are you’re dealing with a hydraulic cylinder trunnion mount. These mounts aren’t just for show—they’re specifically designed to solve real-world challenges in equipment where pivoting movement and stability matter.
Whether you’re working on construction machinery, agricultural equipment, or even industrial presses, understanding how trunnion mounts work can help you avoid unnecessary wear, improve alignment, and get more life out of your cylinder setup.
What Is a Trunnion Mount in a Hydraulic Cylinder?
A trunnion mount is a pair of pivot points welded or bolted onto the cylinder body (not the ends). These pivots allow the cylinder to rotate around a fixed axis as it extends and retracts. Unlike clevis or flange mounts that attach at the ends, trunnion mounts hold the cylinder near its midsection.
This allows for more stable and natural angular movement—especially useful when the equipment has moving arms or changing angles during operation.
Why Use a Trunnion Mount Instead of Other Mounting Types?
1. Flexibility in Angular Movement
Trunnion mounts allow the hydraulic cylinder to pivot during operation, which is crucial for equipment that moves in arcs or shifts under load. It reduces binding and helps maintain alignment with the machine’s structure.
2. Ideal for Pivoting Applications
If you’re working with equipment like excavator arms, dump beds, or tilting mechanisms, a fixed end mount can create side loading—which wears out seals and rods. Trunnion mounts help the cylinder follow the motion naturally, avoiding that stress.
3. Better Load Distribution
Because the trunnion is positioned closer to the cylinder’s center of gravity, the load gets distributed more evenly across the mounting structure. This helps reduce wear on pivot points and keeps the frame from twisting under force.
Common Real-World Applications of Trunnion Mount Cylinders
Trunnion-mounted cylinders show up in more places than you might think. Here are some real examples:
- Backhoes and excavators: Boom arms often use trunnion-mounted cylinders to allow for smooth pivot motion while digging or lifting.
- Dump trucks: Telescopic cylinders used to lift the bed sometimes use trunnions to allow better control and avoid binding.
- Hydraulic presses: In large industrial presses, trunnion mounts handle repeated up-down strokes with better alignment.
- Heavy agricultural sprayers or plows: Trunnion mounts allow cylinders to compensate for uneven terrain and shifting implement angles.
Choosing the Right Trunnion Mount Cylinder: What to Look For
Before buying or specifying a hydraulic cylinder with a trunnion mount, here are a few key factors to consider:
- Mounting orientation: Decide whether you need a rear trunnion, center trunnion, or front trunnion mount, depending on your equipment geometry.
- Operating angle: Ensure your mounting points allow for enough pivot clearance to prevent side loading.
- Bore and stroke size: Match the force and travel requirements to your application—don’t just guess.
- Material and weld quality: The trunnion mounts take a lot of load. Poor-quality welds or cheap trunnion pins can fail under pressure.
Many OEMs now offer trunnion cylinders in standard configurations, but for specialized machinery, you may need a custom solution. If in doubt, consult your equipment manual or a hydraulic engineer.
Common Mistakes to Avoid When Installing or Specifying Trunnion Mounts
Even experienced mechanics and engineers make these avoidable errors:
- Incorrect trunnion axis height: Misalignment causes side loads and premature rod seal wear.
- Underrated pin diameter: Too small a pin can shear under repeated stress, especially in high-load or fast-cycle applications.
- No provision for rotation: Forgetting to allow rotational movement at both ends of the cylinder leads to binding and metal fatigue.
Trunnion mounts must work together with clevises or spherical bearings to allow full, natural motion—otherwise, the benefits are lost.
Maintenance Tips for Long-Term Performance
Once installed, trunnion-mounted cylinders are low-maintenance—but not maintenance-free. Here are a few best practices:
- Grease trunnion pins and pivot joints regularly, especially in dirty or wet environments.
- Inspect for slop or side play—this can indicate bushing wear or pin elongation.
- Check for hairline cracks in trunnion welds during routine inspections.
- Monitor alignment and watch for signs of rod bending—this means mounting issues.
A little routine attention can add years to your hydraulic system’s life, especially under heavy daily use.
Final Thoughts: Is a Trunnion Mount Right for Your Job?
If your hydraulic setup involves moving parts, pivoting structures, or heavy lifting at odd angles, a hydraulic cylinder trunnion mount is likely the smart choice. It offers flexibility, load balance, and motion control that end mounts just can’t match.
But like any tool, it’s only effective if installed and maintained properly. So whether you’re buying a new cylinder or upgrading an existing one, take the time to understand how a trunnion mount fits into your system. Done right, it’ll keep your equipment moving smoothly for years to come.
It is recommended to use various types of hydraulic cylinders, dump truck hydraulic cylinders, and top hydraulic cylinders of our company
Whatsapp
