Energy chain systems can not only transport energy, data and media to machines and systems, says manufacturer igus UK. They can also influence their energy consumption costs
How much pull-push force, or driving force, is required at a given speed to move an energy chain? How light or stable do energy chains have to be for minimum energy to be consumed? Modern plastic energy chains and Chainflex cables from igus can help in the design and operation of machines that are efficient in terms of energy and cost.
Energy consumption can be significantly reduced by using the right materials and the right design, as current tests at the igus energy chain and cable laboratory show. For example, long travel distances with high fill weights: if a roller energy chain is used in place of a sliding application, friction loss is reduced. Tests show that with the same basic data (filling, chain length, speed and acceleration) the friction factor can be reduced from 0.3 to under 0.1. And thanks to the user of the roller energy chain, says igus, the drive power was reduced by 37 per cent compared to the equivalent sliding application.
Modern plastic instead of steel
Such roller energy chains for long distances developed by igus have been in use globally for several years. One example is the 550m chain used in a taconite mine in Minnesota: another is the longest plastic energy chain in the world so far, a 615m unit in the lignite-fired power plant at Tusimice in the Czech Republic, pictured above.
Metal chains are being replaced more and more now by lighter and lubricant-free plastic energy chains even in the toughest of working conditions. The latest example is in a steelworks in Isfahan, Iran, where dust, lubricants and oils impaired the functional ability of the heavy metal chain that had to be pulled by the machine. Cables were damaged by sharp chain edges and permanent sun radiation.
Alongside the reduction of the friction coefficient illustrated by roller energy chains, there are further factors which favour efficient energy management, adds igus. Size and weight, for example:tests in the igus Technical Centre have shown that 17 per cent drive power can be saved with smaller energy chains which are as robust as larger chains due to their careful design.
A strong energy chain from the E4 range was chosen: this is a comprehensive, modular system that can be used to realise almost all applications from side-mounted and hanging applications, through to long travel distances of over 200m. The new E4.1 generation of energy chains offers a number of application possibilities, since design features from previous energy chains, as well as new design features, have been merged into one new design.
Cables: sheathing and insulating materials
Chainflex cables especially for energy chains can help directly in reducing energy consumption. According to the latest igus tests, the use of high-grade sheathing and insulating materials, depending on the combination of cross-sections and cables used, can ultimately save between five and 30 per cent of energy consumption. The result here is that the drive power requirements can be reduced by around 17 per cent.
Firstly, optimised sheathing materials, matched to the energy chain application, can achieve low abrasion resistance. Secondly, high-quality sheathing materials can be extruded with an extremely thin wall, which saves up to 18 per cent in weight compared with conventional cables. Insulation materials must also be considered. With high-quality materials, significantly higher current carrying capacity can be achieved with the same core cross-section, or the cross-sections can often be reduced without the electric performance being diminished. This allows weight reductions of up to 30 per cent.
