Culturally, the term ‘linear’ has gained an unfair reputation in the past few decades. To declare that something is linear is to suggest that it is lacking in complexity; it is plain, straightforward, simple, there is no deviation, and no unknown quantities where choice can come in.

Of course, when it comes to manufacturing, that’s exactly why linearity is so crucial. In demanding applications such as factory automation, the danger is of having systems or processes that aren’t linear enough. Nearly straight won’t do – production lines depend on machinery that will reliably move along a pre-determined axis, over and over again.

To achieve that quality of linear transfer, design engineers use linear guides. In principle, it’s the same technology that helps people around the world to open clothes drawers, reliably and without trouble, day after day. Yet the stakes are considerably higher in a factory setting. A linear guide needs to be strong and frictionless. It must maintain its performance over thousands, if not millions, of repeatable movements, and it must withstand forces without becoming deformed.

Which linear guide is right for you?

Selecting the right linear guide isn’t a simple matter, and it’s important to get it right. There are two main types of linear guide system, each with its particular characteristics.

Slide guides are linear guides in which the individual linear guide elements are not separated by rolling elements. In contrast, roller guides are based on a rotational mechanism, whereby roller guides such as rollers or ball bearings are rotated between two moving elements.

Either way, though, the end result is the same: the linear block moves forward and backward along the plane on which the rail is positioned.

Slide guides

Linear slide guide systems include the dovetail slide from norelem, which prevents a guide element from lifting during rotational movements. The full-contact design of the sliding surfaces makes dovetail slides well-suited for absorbing and damping shocks and vibrations.

Telescopic slides are another option – and norelem now offers 33 types, designs and sizes, providing effective movement for payloads from 10 kg to 450 kg. When putting together this comprehensive range, we placed particular emphasis on reducing friction, noise, and the need for maintenance.

Slide rails are manufactured in steel as standard but are also available in stainless steel or aluminium. Stainless steel is corrosion-resistant and guarantees maximum hygiene: perfect for medical technology. In comparison, aluminium is light, therefore making it ideally suited for applications such as aviation, where every gramme counts.

Roller guides

A rolling element retainer (such as a roller chain) keeps the rolling element in control and ensures that the guide runs as quietly as possible. Roller guides include profile guide rails and linear ball bearings.

Roller guide systems from norelem comprise guide rails with lengths up to 4080 mm and in compact and heavy-duty design sized 20 mm, 30 mm, and 45 mm. Depending on the size and dimensions, the roller guide systems can operate with static loads of up to 5,500 N and dynamic loads up to 12,280 N.

The combination of fixed and floating bearing rail prevents annoying tilting and unnecessary wear of the roller guide systems, the carriage can be made play-free by simply adjusting the central cam roller to the desired tension in the rail. This guarantees precise running, the permanently lubricated roller bearing ensures maintenance-free operation.

Another type of roller guide relates to those which have recirculation rolling elements. Rolling elements recirculate within the linear block and move with the block instead of separately, akin to the tracks of a tank.

What else to consider

As a general rule, a good quality guide depends on its shape, positional accuracy and lack of friction. This means that, when specifying and sizing a linear guide system, you can take a logical approach.

Once you have clearly defined the most important parameters required for your application, you will likely determine whether a slide or roller guide is the best system to use.

Based on this decision, you can then narrow down the selection further based on specific variables, such as speed, load, material, maintenance and more.

Choosing linear systems from norelem

At norelem, we have extensive experience in helping customers to choose the right linear guide system. Our linear guides are used in industries as varied as semiconductor manufacturing, robotics, packaging and medical technology – although, understandably, the primary field of application is factory automation.

Where required, we are happy to advise customers on the right specification for positioning, manipulating, lifting or rotating production elements. This means that our linear guide systems can be assembled according to the customer's specific application.

In short, a linear guide is a simple device, which does a simple job well. Next time somebody complains about something being too linear, point them in the direction of the linear guide and remind them that, sometimes, simple is exactly what is needed.

For more about norelem, please visit www.norelem.com

About norelem

norelem is a world-leading manufacturer and supplier of flexible standard parts and components for mechanical engineering. The company supplies 60,000 standard products relating to standard machinery and operating elements, as well as automation components. Ninety-eight per cent of these parts are available from stock, and the business delivers on-site technical support for products. This high level of inventory enables norelem to provide fast and reliable delivery times.

About THE BIG GREEN BOOK

THE BIG GREEN BOOK is both norelem’s ideas catalogue and a reference book, and has become the norelem trademark. More than just a standard product catalogue, THE BIG GREEN BOOK represents everything norelem stands for, combining product information, specifications, and technical information, with best practice references, advice, and guidance.

THE BIG GREEN BOOK combines product information, specifications, and technical information in one single source. Created using a logical sequence of article numbers based on stages of production, it contains best practice references, advice, and guidance.