Written by: FABCO-AIR
DRAKE supply professional and honest service.
Compact air cylinders are critical to a wide range of applications, including printing, palletizing, robotics, automotive assembly, semiconductor processing and more. This type of pneumatic actuator provides short strokes in a compact, low-profile design-enabling you to use it in very tight spaces. With bore sizes from 0.5-4 inches and a maximum standard stroke of 4 inches, these cylinders typically feature the longest possible stroke for the smallest package size.
In light of their value and widespread use, it&#;s important to remember that not all compact air cylinders are created equal. There are a number of products currently competing for your attention and a share of the actuator market. Many of these components have similar features. Some even look alike-featuring the exact same exterior dimensions. How, then, can you decide which cylinder to use?
This white paper provides a helpful overview of air cylinder design and also explores the key features you should look for when selecting a compact cylinder for your application.
To specify the right air actuator, it&#;s helpful to ask yourself two main questions. The first is: What type of work does the cylinder have to perform? The second is: What types of cylinders do you have to choose from?
Compact air cylinders typically come in a wide range of styles, sizes, and mounting options (see sidebar). They can be double-acting, which is ideal for pushing and pulling tasks like feeding, lifting, lowering, and sorting. They can also be single acting, an ideal configuration if your application requires force in only one direction or involves unloaded return strokes. For safety reasons, single-acting cylinders are also popular if a defined position must be taken in the event of a power failure. Typical tasks for this style include clamping, ejecting, and actuating flaps and levers.
Compact air cylinders also come in single or double rod designs. A more common option, single rod designs often include a spring that extends or retracts the rod. Double rod cylinders, on the other hand, are useful whenever you need equal displacement on both sides of the piston. You can also use the extra end to mount cams for operating limit switches.
In addition to specifying the right configuration, it&#;s important to make sure your compact air cylinder meets the proper size requirements. Due to their use in tight or limited spaces, look for standard bore sizes between 0.5 and 4 inches, as well as standard strokes up to 4 inches.
To truly evaluate a compact air cylinder, it&#;s helpful to take a look at what&#;s inside. High-performing cylinders will integrate top-of-the-line internal components. Our Pancake® cylinders, for example, incorporate stainless steel tie bolts and aluminum spacers, which lock precision-machined heads tightly around a strong composite cylinder barrel. This type of nonmetallic barrel features a smooth, self-lubricating interior surface that ensures reliable, long-lasting performance. At the same time, its high impact resistance reduces the chances that the cylinder will fail due to damage. By contrast, many compact air cylinders currently on the market integrate stainless steel cylinder walls, which-unlike nonmetallic composites-are subject to dings, dents and other damage. Many also include mirror-finished bores, which make lubrication difficult.
Due to their zero slipstick design, Pancake® cylinders also avoid the stiction problems metal cylinders encounter when they sit in a static position for too long. Combined with hard, chrome-plated stainless steel piston rods, as well as a nonmetallic rod bearing, Pancake® cylinders achieve optimal operation and service life.
The better the bearing, the more cycles you can expect from your air cylinder. Look for compact cylinders with superior rod-bearing materials. Pancake® cylinders, for example, incorporate a fluoropolymer-based composite that is bonded to a supporting filament-wound fiberglass and epoxy resin shell. This material resists corrosion, moisture and temperatures up to 325° F, enhancing the bearing&#;s load capacity and reliability in harsh environments. Many cylinders on the market feature oil-impregnated bronze bushings, which tend to pull out under side loads. These models also have a lower load capacity than composite options: 4,500 VERUS 60,000 PSI.
In addition to composite cylinder walls and rod bushings, other important internal design features to look for in compact air cylinders include:
Compact air cylinders like the Pancake® series play a critical role in a variety of applications-from conveyor systems to custom-built machinery. These highperforming cylinders come in a variety of styles and configurations. They also meet the right size requirements for use in tight or limited spaces. But most importantly, these cylinders incorporate high-quality internal components-enhancing your cylinder&#;s durability, reliability and lifespan in short-stroke applications.
Brought to you by FABCO-Air, a partner of DIRECTPNEUMATICS.COM
Want more information on double rod cylinder? Feel free to contact us.
Hydraulic cylinders, jacks, or rams. The names vary but whatever you choose to call them the definition is the same. A hydraulic cylinder is a device that harnesses the pressure generated in a hydraulic system to move a load. Due to the wide variety of cylinder options to choose from, you will need to consider your needs carefully when selecting a cylinder for your job. Answering just a few questions will help you to choose the right hydraulic cylinder for your lifting and pulling projects.
Cylinders are versatile products. Not only are they used for lifting and jacking, but also for pulling, pressing, holding, lowering, and clamping. Knowing the application you need a cylinder to perform is your first important step towards making the right decision.
Hydraulic cylinders are used for countless applications. Many job sites involve harsh conditions, whether that being extreme heat, or the rough conditions of a construction site. Cylinders with a nitrocarburized surface treatment have increased corrosion protection. This makes them much more durable and ideal for harsh environments.
The question of how much room you have for your cylinder is an important one. You wouldn&#;t choose a cylinder that has a collapsed height of 16.5cm (6.5 in) for a space that only has 12.7cm (5 in). There are purpose-designed cylinders made for jobs in confined spaces. These go by the name of low-height cylinders, or pancake cylinders.
Related to the maximum collapsed height, is the stroke length required. Stroke is defined as the difference between the fully extended height and the fully retracted height of the cylinder. It&#;s the distance between the top of the plunger piston and the bottom of the stop ring. For jobs that need extra stroke, there are telescopic hydraulic cylinders including low-height versions. The stroke determines how far the cylinder will lift, push, pull, or move your load. When considering the stroke of a cylinder, you should keep within 80% of the maximum stroke. This helps ensure better stability and damage from sideload.
Hydraulic cylinders are available in single acting and double-acting configurations. A single-acting cylinder uses hydraulic pressure to extend the plunger and a return spring to bring it back to the original position. A double-acting cylinder uses hydraulic force to both lift and lower the plunger. This provides much more control and precision.
If your load needs holding in place while you perform your job, a cylinder with load holding is a safe choice. Cylinders that hold your load, eliminate the time-consuming process of cribbing. There are two different types of cylinders that can be used for load holding. Locknut cylinders which utilize mechanical support, and cylinders with check valves.
Each hydraulic cylinder is built to lift a certain capacity. There are general-purpose designs, which are your &#;basic&#; options, and also high tonnage cylinders that have a capacity of up to tons. Like cylinder stroke, the 80% rule also applies to tonnage. Manufacturers always list their maximum weight capacity as a safe limit. However, good practice with cylinders encourages users to only go to 80% of the manufacturer&#;s limit.
If you&#;re looking for a cylinder for regular use, you will need one that&#;s built to last. Steel cylinders are inherently stronger than their aluminium counterparts. However, if weight is an issue, aluminium cylinders are also robust and much easier for a person to lift, transport, and reposition.
Some jobs need extra stability or precise cylinder positioning. If your job falls under that category you will need a hydraulic cylinder with either mounting holes or collar threads. Mounting holes are located on the bottom of the cylinder&#;s base and can be attached to a base plate.
For many larger lifts, you may need more than one cylinder. If that is the case, you will need to select a pump with the appropriate oil capacity. You may also want to think about a synchronized lifting system. A synchronized lifting system will ensure your load&#;s weight is distributed evenly.
A hollow plunger hydraulic cylinder design allows for both pull and push forces. This is achieved thanks to a threaded collar for attaching suitable fixing rods.
In many lifting projects, sometimes it is difficult to achieve sufficient contact between the saddle and the load. When this happens there is the risk of damage to the cylinder from side loading &#; often with the user completely unaware it is happening. A greater contact area can be achieved using Tilt Saddles. These are an option that can be specified to work with a wide range of cylinders and help extend the life of the cylinders.
Ok so you&#;ve answered the questions above and have a cylinder in mind. Good job! But before making your final selection, don&#;t forget to check whether the hydraulic pressure from your pump will be sufficient. If you need an upgrade there&#;s many great pumps to choose from. For example, plugin manual, electric, battery, air over hydraulic, and lightweight models for working at height.
Keep these things in mind when looking for a cylinder and you will come away with the best option for your application. If you have any more questions about how to choose the right cylinder, you can easily get in contact with your local Enerpac territory manager or distributor here.
Here&#;s a checklist to summarize;
If you want to learn more, please visit our website strokecontrol.