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Say “thanks” to a pneumatic actuator subsequent time you take pleasure in a craft beer. Or eat a watermelon. Or open a can of paint. Or work together with any of numerous objects, from automobiles to drugs, in your each day routine.

The workhorses behind the scenes of our fashionable lives are linear actuators that push, pull, rotate, clamp, transfer and place the merchandise (or the machines that make the merchandise) we use every single day. This text discusses the various kinds of actuators, additionally known as cylinders, after which highlights methods through which actuator options may be chosen for optimum effectivity and efficiency in particular purposes.

Sorts of Pneumatic Actuators

Essentially the most acquainted industrial pneumatic actuator is a rod-style cylinder. A rod connected to a piston inside a barrel or tube extends by a sealed opening at one finish. The load is related to, or contacted by, the rod. Compressed air managed by a valve enters the barrel and strikes the piston, which strikes the rod. A port on the different finish permits the air to flee. The rods of single-acting actuators are moved by compressed air and return to their beginning place by way of a spring return. Double-acting actuators are moved by compressed air in each instructions.

One other sort of pneumatic actuator is the rodless cylinder. As an alternative of being moved by a rod, the load is moved by an exterior carriage alongside the tube’s floor. Rodless cylinders save house and may ship longer strokes than rod-style cylinders as a result of the stroke is contained inside the general envelope of the cylinder. Rodless cylinders additionally deal with excessive second—the forces appearing above, under, or to 1 aspect of the middle of the piston.

Match the Actuator to the Utility

Deciding on the appropriate actuator for an software begins by answering a couple of easy questions:

  • What’s the desired finish results of the operation?
  • What work will the actuator carry out—raise, push, open/shut?
  • How giant or heavy is the load?
  • How far should it transfer?
  • How shortly should the cylinder strike and recuperate?
  • How will the movement be stopped?
  • What’s the working setting?

Realizing what the cylinder should do helps designers perceive how a lot pressure can be required, which can decide the bore dimension. It is going to additionally information choices about cycle pace, which determines throughput, productiveness, longevity, and controllability. Designers might also have to calculate a cylinder’s air consumption for fast-cycling manufacturing gear to make sure that the compressor system has adequate capability.

Traditional, with a Twist

Pneumatic cylinders are a dependable expertise, confirmed over many years of efficiency. It’s straightforward to take them as a right or see them as commodities, however there’s extra selection in use and in design than you may assume. Listed here are just some fast examples.


A craft brewery in Colorado wanted to extend manufacturing capability and effectivity, however had no room for a brand new manufacturing line. They solved the issue with a rotary kegging machine. Linear actuators on high of the machine management the movement of the kegs by the method.

These actuators combine the valve, move controls, cushioning, and sensors in the identical package deal because the actuator, eliminating a number of valve islands, exterior parts, tubing, and equipment. This mixed with a clear exterior package deal not solely saves house on the machine, however permits for straightforward, thorough washdown as required by this software.

The cleanline profile and diminished tubing of the built-in actuator and valve management cylinder mounted on high of this rotary kegging machine save house and make washdown straightforward. (Picture copyright Norgren Inc.)

Material Provider

Reasonably than transfer yards of cloth by a stitching machine, a customized material provider mounted the machines underneath rodless cylinders in order that they might transfer exactly and evenly from stitching station to station. Rodless cylinders are particularly well-suited to this software, as a result of hundreds may be mounted on high, beneath, or alongside the aspect of the cylinder. They’ll additionally deal with a stroke size as much as 27 ft, and transfer in both course with the identical pressure.

Rodless cylinders, just like the Lintra Cylinder from IMI Norgren, may be mounted horizontally or vertically and carry hundreds on high, beneath, or to the aspect. (Picture copyright Norgren Inc.)

Bread Baker

Getting bread to rise generally is a delicate operation. An industrial bread-baking OEM discovered that extreme vibration throughout manufacturing was inflicting the bread to rise inconsistently, or worse, in no way. Changing current pneumatic cylinders with cylinders that had a specialised elastomeric seal on the finish of the tube diminished vibration, and product high quality instantly improved. Better of all, this enchancment was achieved with out sacrificing cycle pace; due to this fact, with the identical excessive throughput and fewer waste, productiveness soared. And diminished vibration means longer machine lifetime of each the cylinder and peripheral parts.

Alongside these strains, try IMI Norgren’s video on its actuators that make use of “Ecology Seals”:


This revolutionary cushioning has the added benefit of decreasing noise. The clanging of the metallic piston because it hits the cylinder’s metallic finish cap at excessive speeds can create noise at decibel ranges that require ear safety. Eliminating the metal-to-metal influence helps scale back noise ranges to acceptable OSHA requirements.

Utilizing cylinders with elastomeric seal cushioning dramatically reduces noise and put on brought on by influence and vibration with out considerably decreasing the variety of cycles over a typical eight-hour shift.

Melon Sorting

Linear actuators are used to type every kind of issues, together with watermelons. Because the melon passes over a scale, a sign is distributed to the actuator that corresponds to the melon’s weight. The actuator opens a gate that diverts the melon into the right bin.

A brand new configuration being examined integrates the actuator with a delicate pad on the finish in order that it may push the melon straight with out damaging it. Not solely does it scale back complexity and enhance pace on the road, however this mix can be offered as a unit with a single half quantity, simplifying buying, stocking, and upkeep.

An knowledgeable cylinder provider can mix the appropriate actuator with different parts to fulfill motion-control challenges, like sorting watermelons, precisely and effectively. (Picture copyright Norgren Inc.)

Bucket Closure

A machine designed to automate closing of pails and paint buckets makes use of linear actuators in two instructions. Horizontally, they transfer the pails down the road. Vertically, the actuator lowers an array of grippers that place the lid after which push it down securely.

When it comes time to design the subsequent machine, processing line, or plant, get artistic with a flexible pneumatic cylinder in certainly one of its many types. There’s virtually definitely an actuator to carry out any motion-control job, giant or small, wherever compressed air is offered. And the subsequent time you open a package deal or undergo a car-wash door (or eat a watermelon), thank a pneumatic actuator.


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