What is a Linear Rail?

If you manufacture, pack and distribute things, if you need to move things through your manufacturing process with great precision and as little friction as possible the very best way to do that is using Linear Rails. Linear Rail are devices used widely used across the full range of industrial sectors.

A Linear Rail System is designed to support the movement and load of a piece of equipment in a linear way, either vertically or horizontally. A relatively simple piece of mechanical equipment designed to do a very simple job well, it lets you move things smoothly and safely through the manufacturing or packaging process.

The only real complexity lies in the different names used for Linear Rails: linear guide rails, linear guides, linear guideways, linear slides, and linear guidance systems. Whatever you prefer to call it, a Linear Rail efficiently moves loads along a determined horizontal or vertical path with a minimum of friction or resistance.

Linear guide rails are usually made from high-strength, hardened and galvanised Steel so they resist corrosion. Manufactured using a cold drawing process, the metal is shaped and profiled before adding a roller runner. As a rule profiled rail guides are the most suitable for high loads, also being designed to deliver a very precise linear motion. Rail guides come in every size from miniature Linear Rails designed for moving tiny components in limited spaces right up to mammoth examples for moving components that could weigh more than a tonne.

What are the common applications for a Linear Rail?

Because there’s such a wide variety of sizes, accuracy classes, and preloads available, Linear Rails are suitable in virtually any circumstance.

Linear rails tend to perform better than other guide devices thanks to their load capacity, displacement accuracy, and rigidity. For this reason Linear Rails form the basis of many varied industrial applications. Whenever you need a low-friction guide system with high rigidity for loads weighing anything from a few grams to a few tons, there will be a linear rail suitable for your unique performance requirements.

Their load capacity, travel accuracy, and rigidity are all better than other solutions. Whereas a round shaft guide only withstands downward or lift-off loads, for example, Liear Rail guides can withstand downward loads, lift-off loads and moment loads. Unlike crossed roller guides, which only travel a limited distance, they can deliver impressively long travel increased stiffness, rigidity, and long life also contribute to their popularity.

If you need a system that’s suited for applications that require high precision, high rigidity, and long life, a Linear Rail is the perfect solution.

What are the challenges of using Linear Rails?

Linear rails come with some common challenges which are easily overcome if you take account of the following:

1. Never ignore the effect of materials and plating on the cost and lead time. Plating, for example, may have to take place overseas
2. Don’t forget to fabricate your mounting surfaces to tolerance. Misalignment of the mounting surfaces directly adds preload to the system
3. Specifying the preload inaccurately means you can’t reduce negative factors like vibration, noise, heat generation, and deflection – significantly increasing friction and degrading performance
4. Failure to test over the full run means if there’s a problem, you won’t know about it until it’s too late
5. Not including mounting features for alignment means the system won’t perform to specification

How do you go about specifying a Linear Rail?

The best approach to specifying and sizing linear rails is a logical one. First, clearly define the most important parameters of the application. Then you need to narrow down your choices based on these requirements, and finally apply your critical variables to make the right final choice.

Your choice includes the profile of the rails, commonly square or round. It involves the kind of bearings, either cantilever or saddle slides, plus the stroke, load, speed, duty cycle, mounting area, and of course the mounting orientation, simply because the saddle could potentially move horizontally, vertically, along a wall mount, or even be inverted.

How do you maintain a Linear Rail for optimum performance?

Any system with moving parts will eventually wear out. Under-lubricated guides can wear excessively, which leads to performance problems and premature failure. Lubrication and characteristics of the lubrication product used make all the difference, and successful lubrication will depend on the quality of the lubricant applied.

Some guides come with automated lubrication systems, but they can be complicated and cost a lot. Maintenance free bearings are simpler, integrated mechanical features added to the bearing slider to store and deliver the lubricant.

The best way to head problems off before they become serious is to look and listen – a change in the sound the system makes can indicate it isn’t lubricated enough, the guide rails are misaligned, or there’s uneven loading on the bearing blocks. The seals, which keep dirt out and lubrication in, are usually easy enough to inspect and replace. And when you use components that are easy to replace, using interchangeable linear rails and bearings plus ball nuts with an adjustable preload, it makes your life a lot easier.

Any questions about Linear Rails?

We know everything there is to know about Linear Rail Systems and hold stock which is available on short lead times. If you have questions, please do not hesitate to call + 44 330 223 5344 or email sales@sandfieldengineering.com, we’ll be more than pleased to answer them for you.