Pneumatic cylinders are mechanical components that provide linear force to various devices and systems. They generate the force by applying compressed air to one side of a sealed barrel and exhausting it from the other side. This action causes the piston/rod assembly contained inside to extend or retract.
It is important to install pneumatic cylinders correctly. Otherwise, there is a risk of inaccurate or unreliable operation and premature failure. This is especially true for hydra-pneumatic cylinders, which generate high forces in a small package. As such, incorrect installation can lead to severe equipment damage and/or operator injury.
Below, we discuss how to install a pneumatic cylinder properly. Additionally, we highlight the importance of testing the system before putting it into operation and the precautions to take when performing installations.
How Do I Install a Pneumatic Cylinder Properly?
There are two essential fixing points to consider when installing a pneumatic cylinder: the body and the piston rod end. How these points are fixed depends on the application.
In static applications, the cylinder can be mounted to the machine bench and fixed rigidly to its structure. Both pneumatic and hydra-pneumatic cylinders are typically mounted with a rectangular front flange mount (also sometimes called an MF1 mount or FH mount) or tapped holes in the front of the face (also sometimes called an MR1 mount or UH mount) due to the high forces generated. However, some pneumatic cylinders use a semi-rigid trunnion mounting method (MT1) that utilizes body supports or pivots and clevis pins. It allows them to rotate as they follow the extension and retraction of the piston rod. In rare cases, a side lug mounting method (MS2T mount) may be used.
In complex linkage applications, the cylinder must be able to swivel on its mountings. There are several solutions to this mounting requirement. For example, a front clevis, central trunnion, or rear hinge can be used on the body of the cylinder to allow the cylinder and load system to achieve different degrees of balance. Alternatively, a clevis, front hinge, or universal eye can be used at the end of the piston rod to mount swivel attachments. If a trunnion mounting method is chosen, it is essential to ensure the cylinder can oscillate freely on the mountings and the pipe connections can flex when in use.
Some of the things to keep in mind when installing a pneumatic cylinder include:
- Minimize or eliminate side loading. Side loading is highly damaging to pneumatic cylinders. Ensuring the cylinder is correctly aligned and properly mounted can reduce the risk of it occurring. An alignment coupler or die set coupling can also eliminate or minimize side loading when attaching the rod end to the tooling.
- Lubricate the bearing slides and trunnions. The bearing slides and trunnions should be lubricated as per the manufacturer’s guidelines.
Why Should I Test the System?
Before putting a cylinder into operation, it is critical to test the entire system to ensure the component actuates with minimal resistance and the rod experiences minimal side loading. Testing operations can be conducted by using a flexible air line and blow gun to check the cylinder is installed properly and able to move freely at the published minimum operating pressures. For hydra-pneumatic cylinders, it is vital to test them in low pressures (approach and retract) without going into high pressures (intensification) to ensure the tooling and overall setup are aligned correctly. These testing operations should follow the manufacturer’s guidelines for sequencing the cylinder for approach, retract, and intensification.
What Precautions Should I Take When Installing Pneumatic Cylinders?
There are many considerations to keep in mind when installing a pneumatic cylinder. Be sure to take the following precautions to ensure safe installation:
- Avoid attaching unsupported loads directly to the piston rod. Use roller guides or a slide to support the load.
- Minimize bending moments. Suspend the rod end from a roller track or another form of external guidance if it has a long out-stroke and high shear weight. Install external bearings, or guides, to reduce side loading wherever possible.
- Align the pneumatic cylinder and guided loads properly. The use of alignment couplers, or die set couplers, will overcome minimal alignment issues.
- Use properly conditioned air, according to the manufacturer’s recommendations. Particulate filtration, removal of water (moisture), and other contaminants is important for nearly every manufacturer’s cylinders and pneumatic valves.
Hydra-Pneumatic Cylinder Solutions at HyperCyl
If you’re looking for hydra-pneumatic cylinders and presses for your assembly and forming operations, turn to the experts at HyperCyl. Equipped with more than 20 years of experience, we have the knowledge and skills to help you identify the right equipment for your needs. Our products are carefully designed, assembled, and installed to allow for greater process control, higher retract force, and better cost savings.
For more information about pneumatic cylinders or our product and service offerings, contact us or request a quote today.
Hydra-pneumatic cylinders—commonly referred to in the industry as hydro-pneumatic cylinders, air-over-oil cylinders, or intensifier cylinders—are pneumatically controlled cylinders engineered to generate higher hydraulic pressures to achieve a greater stroke force than can be attained by solely pneumatic cylinders of the same bore size. For example, a 5-inch bore pneumatic cylinder can output less than 1 ton of force at 100 psi, while a 5-inch bore hydra-pneumatic cylinder can produce up to 10, 15, or 20 tons of force, depending on the design.
The following blog post provides an overview of hydra-pneumatic cylinders, including how they work, key features, typical applications, and solutions at HyperCyl.
How Do Hydra-Pneumatic Cylinders Work?
In contrast to strictly pneumatic or strictly hydraulic cylinders, these hybrid cylinders rely on the surface area differential of an internal pneumatic piston-rod assembly to significantly increase the pressure of trapped oil above the work piston, to provide an intensified hydraulic cylinder output force. Initially, they function similarly to pneumatic, double-acting cylinders, extending and retracting to the workpiece with output forces typical of pneumatic cylinders. However, once in contact with the workpiece, a second pneumatically controlled cylinder section drives a rod into the oil section, sealing it off, and intensifying the internal pressure. The intensified oil pressure pushes against the work piston, producing an increased output thrust, typical of hydraulic cylinders.
Similar to other double-acting pneumatic cylinders, hydra-pneumatic cylinders utilize valves to control their motion. They have one four-way valve to control approach and retract motion, and one four-way valve to control oil pressure intensification. This design combines the advantages of pneumatic and hydraulic cylinders without any of the disadvantages (e.g., excess heat and noise, space limits, or risk of leaks). Compared to strictly pneumatic cylinders with a multi-stage design, these cylinders consume only about 1/4 to 1/3 of the air.
Key Features of Hydra-Pneumatic Cylinders
While hydra-pneumatic cylinders come in a variety of designs to suit different applications, some of their key features include:
- Three major moving components
- Simple control circuits
- Total/air oil separation on both sides of the oil
- Wear bands on the reservoir and work pistons
- Linear output forces up to 200 tons
- Heavy-duty construction for durability and reliability
- Tie rods with tensile strengths of 100,000 psi
- Mean time between failure (MTBF) of 4.7 million strokes
- Service life of 20 million strokes
- Operational capacities in any position or attitude
- Medium-duty mounting styles compliant with National Fluid Power Association (NFPA)
- Included repair manual and field serviceable seal kits
- Options for gage kits, sensors, total stroke limiters, alignment couplers, and more
Typical Industry Applications for Hydra-Pneumatic Cylinders
The full line (six series) of HyperCyl® hydra-pneumatic cylinders are designed for machine builders and OEMs to use in their own presses and automation, as well as for use in HyperCyl supplied presses. HyperCyl presses are available with “C” frames or “H” frames, unguided, two-column guided, or four-column guided upper bolsters, and bench-mounted, pedestal, or machine base configurations. Due to their modular design, machine designers can choose a simple frame and drive unit design that facilitates integration into a larger assembly process, or a turnkey design that incorporates automation technology, controls, and more.
HyperCyl presses find use in a wide range of production applications, such as:
- Part insertion and assembly
- Material piercing
Why Partner With HyperCyl for Your Hydra-Pneumatic Cylinder Needs?
HyperCyl by Aries Engineering Company (AEC) is a privately owned company based in Dundee, Michigan. We specialize in the manufacture of hydra-pneumatic cylinders and presses for assembly, piercing, and forming applications. By utilizing our cylinders, our customers benefit from the following:
- Greater Process Control: Our cylinders allow for separate regulation of the approach stroke and power stroke, which allows for more complete control over the process without the need for cylinder reconfiguration.
- Higher Retract Force: Since our cylinders generate greater retract forces, they can accommodate the attachment of heavier tooling.
- No Stored Energy: Our cylinders do not use mechanical springs to move the pistons, which can break and hinder/halt operations. There are no unexpected motions from stored energy in HyperCyl cylinders.
- Better Cost Savings: Our cylinders consume less air than other pneumatic cylinders. Our cylinders take up less space, generate less heat and noise, and cost less to purchase than a hydraulic cylinder and power unit. Additionally, they offer faster operational speeds and a smaller risk of leakage.
All of these qualities translate to lower investment, operational, and/or maintenance costs.
Source Hydra-Pneumatic Cylinders from HyperCyl
Since 1994, we’ve helped our customers determine the force and stroke requirements for their applications to help them design and purchase the right equipment for their needs. By evaluating their parts with our in-house equipment, we help identify the forces needed, and which actuator is best suited for their assembly, piercing, or forming application. All supplied materials are accompanied by complete evaluation documentation and reporting. We also offer access to an extensive database of hundreds of previous assembly and forming applications for examples of our capabilities.
To learn more about our product solutions and how they can benefit your assembly or forming application, contact us today. To discuss your application requirements with one of our experts, request a quote.