A Guide To Air Cylinders

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compressor air cylinder
(Last Updated On: August 26, 2020)

As a general rule, air cylinders are not designed to be “bottomed”. By that, I mean that the piston inside the cylinder should not impact the end caps at either end of stroke. The tooling on the rod end should have some method of stopping, so that the piston doesn’t crash into the end of the cylinder, particularly on high-speed, high-cycle-rate applications.

If modifying the tooling with shock absorbers or fixed stops is counterproductive or too expensive, then by all means, use the piston-to-end-cap impact as a method of stopping the cylinder stroke and the tooling.

Just be aware that it won’t be too many hundreds of thousands of cycles before the rod breaks from the piston, or the piston itself cracks.

This may not be an important issue on a $50.00 throwaway cylinder, but what about a $2,000 dollar unit?

 

If you need to move a load within the length of the air cylinder….

Then you’ll need either a cable, band or magnetically coupled cylinder.

All of these types are considered “rodless”, meaning that the carriage to which the load is attached, moves along the cylinder barrel as opposed to a “rodded” cylinder that moves a rod in and out of itself.

A footprint for a 12″ stroke rodded cylinder will be at least 24″, while the footprint of the same stroke in a rodless type cylinder will be only slightly more than the 12″, just enough extra length for the cylinder end caps.

 

Air Cylinder Problems?

On the website www.about-air-compressors.com, there’s lots of information about all kinds of air actuators, including much information about what causes problems with them.

The article linked below provides similar information, plus some new stuff about air cylinders that’s worth reading.

 

“Watch when you are sizing your air cylinders…” says Norgren.

They write, “oversizing an actuator by one bore size can result in a 50% increase in the cost of compressed air required for the application. If care is taken in this initial step of the design process, every component upstream of the actuator will have a better chance of being correctly sized and applied”.

Sound advice, I’d say.

 

Air Cylinder Mounting Issue

Whenever possible, use a clevis style mount when installing an air cylinder.

You can have a rear clevis, and/or a rod clevis.

The use of these devices will help compensate for an alignment issue between the air cylinder and the tooling when the air cylinder is cycling.

If the tooling is not aligned correctly with the axial motion of the cylinder, sideloading can result. Sideloading will result in premature cylinder wear and early air cylinder failure.

 

How To Reduce Compressed Air By Air Cylinders

Perhaps not so anymore, but for years the concept was that compressed air was a low cost energy source. Actually, energy consumed in generating compressed air means that it costs four or five times that of electricity, depending on where you are in the world.

Here’s a story that I found interesting about a new concept air cylinder that can reduce compressed air usage by 50%, yet still provide the same force. Even better, this new cylinder is faster than traditional air cylinders.

 

Concept to reduce compressed air use by cylinders.

Perhaps not so any more, but for years the concept was that compressed air was a low cost energy source. Actually, energy consumed in generating compressed air means that it costs four or five times that of electricity, depending on where you are in the world.

Here’s a story that I found interesting about a new concept air cylinder that can reduce compressed air usage by 50%, yet still provide the same force. Even better, this new cylinder is faster than traditional air cylinders.

 

Oscillating Air Cylinders

There are applications for small air cylinders that require fairly rapid and adjustable oscillation. Things like imparting a vibration to a conveyor or bin to help keep product flows or for moving small sifting screens.


Buy this oscillator here; Zeta 3KG JT-51 Square Quartet Electric Oscillator Equipment Lab Equipment

You can design an oscillating circuit yourself. I’ve done so, but it’s a bit awkward to get true adjustability in a self-designed cylinder oscillator circuit.

Never fear, some manufacturers of compressed air equipment can provide an air cylinder oscillator that you simply plumb into the air line before the cylinder to be oscillated. Turn on the air, and the cylinder starts extending and retracting, and these units are infinitely adjustable as to oscillation speed.

Other manufacturers may have their standard unit, but I know for sure that Festo has one. Ask for their VLG-1/8 or VLG-1/4 if you contact them for further information.

 

ISO 6431 air cylinders

ISO 6431 air cylinders are the European standard for a series of air cylinders that, regardless of the manufacturer, will have common port sizes, rod diameters, rod threads, mounting styles, and so on.


Check out the iso air cylinders HERE

In North America, the standard for similar air cylinders is NFPA.

Buying a cylinder that meets a standard means that when you need a replacement, specifying one of that same standard, regardless of source, should mean that the new is interchangeable with the old, with little or no difficulty.

 

Slow your air cylinder down to reduce noise and impact damage

Many industrial machines using compressed air as an energy source, use air cylinders or other pneumatic actuators to do the actual work.

Compressed air is ‘explosive’ as it moves from high pressure to low pressure on it’s way back to atmosphere.

That means when the air valve shifts and air flows to the cylinder, the cylinder piston and rod moves extremely quickly.

A high speed cylinder rod may not be best for your application, and you will want to reduce the speed and the impact.

One easy method of controlling the speed of an air cylinder is installing flow controls in the air lines between the valve to the air cylinder, in the cylinder ports themselves, or even in the exhaust ports of the air valve, though the latter is least desirable.

 

Ultraline cylinders and sensors

Question:

At first, excuse me for my bad english. I try to explain my problem so good as possible. I have to do a documentation for a qualification to become a technician.

In the machine I have to discribe are two cylindres and 6 sensors (all the same style). I need something like a datasheet for this two peaces and the only words, which I read of the peaces , I can give to you is for the cylindres:

ULTRALINE LZ 18/300

for the sensor:

ULTRALINE Model: UL-07R (DC/AC 5-120V. 100mA. 10W).

So I hope you can help my. If there is a need for pictures, I can send You some of the components.

Thank you very much.

_________________

Answer:

And you are welcome, indeed. I’m not entirely sure what it is you seek, but I can tell you, your English is a whole lot better than my German.


Buy this right now here
In any case, Ultraline Ltd is a leading UK manufacturer of pneumatic rodless cylinders and supplier of magnetic sensors, with a network of worldwide distributors. For information on their products you might email them:   sales@ultra-line.com or visit Ultraline’s website at www.ultra-line.com

I sure hope this helps. Thanks for writing in.

Hello, I am Bill, the Compressed-Air-Man. I have years of experience in industrial and residential compressed air applications, air compressors and general pneumatics. I created this site to help professionals, students, and DIYers understand and properly implement and maintain compress3ed air systems.

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