Gliding - long travels

igus® laboratory and practical experience

Our calculations and analyses are based on the results of ongoing practical tests in our Technical Center, as well as the cable carrier experience we've built up over more then three decades. The focal points of our tests include push-pull forces, friction values and wear under widely varying conditions and speeds. We also look at factors such as dirt, weathering, or impacts and bumps. In addition to our cable carriers, we test all our system components, including cables, hoses, strain reliefs, guide troughs and other accessories.

Guide troughs

The guide trough is an important element in long travel applications. Unifilar drawings can be found on this page. Usually, the height of the trough must be at least twice that of the energy chain link height. The sides must provide a chamfered opening. The trough inner width is the same as the energy chain outer width, plus 0.2 inches(B_Ri= Ba + ≈5).Along the side of the trough, where the upper run cannot glide on the lower run, glide bars must be installed. We recommend the use of polymer glide bars from igus®. They are optimally matched to the energy chain material and achieve the lowest values for friction, noise and wear. Guide troughs with and without glide bars can be obtained for almost all igus® energy chains.

Important: when assembling the trough parts, the following points must be given particular attention:

• Properly align all trough parts upon installation
• All screw heads should be flush with the trough
• There should be a smooth leveled transition between the end of the energy chain and the glide bars
• Solid connection with the glide surface. These points must be observed when using assembly-friendly igus® guide troughs.

Ba = energy chain outer width
ha = energy chain outer height
H_Ri = Inner trough height
B_Ri = Inner trough width
H_Ri ≥ 2 * ha
B_Ri ≥ Ba + ≈ 0.2 inches

If the fixed point is in the center of the travel, use half of the guide trough with glide bars and the other half of the guide trough without glide bars.

Travel speeds and accelerations

energy chains can achieve speeds up to 16.4 ft/s in continuous operation and are doing just that in existing applications. In special cases, even higher speeds are possible. For example, E4/00 and E4/4 energy chains achieve speeds of 72 ft/s and accelerations of 2,572 ft/s² in crash test units. Only a few thousand cycles per year are required in this situation. Acceleration plays a large role in the calculation. Differentiations must be made between normal operational acceleration and a sudden jolt in acceleration, such as an unexpected stop. Even in these situations, igus® energy chains prove to be very durable.

Service life

We offer service life calculations for your application based on our extensive gliding application experience. As developers of polymer plain bearings, we possess vast material behavior knowledge which we apply to the development of our energy chains as well. Units with over 650 ft travels have been in operation for 8 years with minimal maintenance. Units up to 197 ft travels have been in operation for 12 years with almost no maintenance. Please consult igus® for references and calculations for your project. The maintenance-free aspects of igus® EChainSystems® over long periods and under demanding operating conditions is often the deciding factor in choosing igus®. Our system guarantee (depends on the application) provides additional peace of mind.

Special properties - Long travel applications

energy chains that are nested can be used in gliding applications. This type of installation is most often used when there is a width restriction. Guide troughs with special wall heights are necessary. energy chains running side by side, or in a "multiband" design can also be used in gliding applications. Higher fill weights often require special guide troughs which can be delivered either from stock or on short notice. Higher fill weights are often a reason for this solution. We have also developed standard parts for unconventional solutions involving large hoses in gliding applications. We have developed standard parts for this purpose, which we'd be glad to offer you on request.

Technical environment

Long travel applications using igus® energy chains run in water, in dirt, in the tropics, in explosion-risk areas (energy chains with special design features) and many other conditions. You will find more details in the Technical Environment section of this chapter. Guide troughs can be supplied in corrosion-free materials.

Calculation

Comprehensive testing means we know our products inside out. Important factors in these tests are:

• Push-pull forces under both ambient and extreme temperatures. Humidity and dirt.
• Friction values of the polymers, alone and against various glide surfaces
• Behavior of electrical conduits under push-pull conditions
• Behavior of hydraulic and media hoses under push-pull conditions
• Service life, and noise generation.