For almost 45 years, igus has developed energy supply systems that reliably guide cables and hoses and protect them against damage. In the beginning, the products were almost exclusively manufactured for the mechanical engineering sector, but the invention of the roller energy chain more than 20 years ago was igus’s breakthrough into other branches of industry.
More than 1000 applications in the crane industry
The phrase “rolling instead of gliding” and an achievable lengthening of service life finally led to a breakthrough in the crane industry.
“In crane technology there are a lot of peculiarities, such as large variations in temperature or strong vibrations as well as movements of the entire plant,” says Theo Diehl, who has been working for igus since 1993.
“One cannot offer ready-made solutions, so each project must be worked out in detail and in collaboration with the customer.”
Diehl was at igus from the beginning of the energy chain revolution, and implemented the initial projects.
“You have the whole world as a field of application,” he says.
“There are projects at +45 degrees C in Abu Dhabi, and at -30 degrees in Finland. One must consider everything when designing the system.”
Crane systems in particular are constantly exposed to some very harsh outdoor weather conditions. The pioneer project was to create a new crane in which vibrations occurring in the energy supply system during wind had to be ruled out.
Since the igus solutions are lightweight but tough enough to withstand the push/pull forces, and very compact compared to alternative energy supply systems, this could then be guaranteed without any restrictions.
The customer’s needs in the foreground
The foray into the crane industry finally led igus to a shift from product to project orientation, and the creation of the project engineering department, which today implements project solutions from conception to execution in many other industries as well.
Close co-operation with customers in the crane industry continued to drive the development of the roller energy chain.
This was also the case with the “4040CR” model for container cranes in Basel, which started service in 2004. The 4040CR’s special feature was reduced noise emissions, particularly in residential areas.
Integrated rollers in the chain links ensure smooth and low-friction operation of the entire system. Since the rollers are integrated into the links of the chain and not additionally moved or needed to run through specified openings in the guide trough, they cannot get snagged.
High performance products set world records
A “heavy duty” version soon followed, and dramatically increased stability and service life expectancy. The “5050R” had reinforced side plates, additional wear surfaces and a pin/bore system reinforced by approximately 40 per cent. This means that even high cable weights could be reliably guided and moved.
These specifications created a world record for roller energy chains, which continue to operate today. In 2007, a 5050RHD was installed in the Czech lignite power plant Tusimice, covering a travel distance of 615m. For more than 10 years, the energy chain has worked reliably “on demand”, sometimes in continuous 24/7 operation, and often after a month of standstill.
Since then, operators of the lignite-fired power plant have benefited from enormously reduced friction and associated savings in drive energy of around 57 per cent.
The heavy-duty version is also used in the crane bridge of double girder bridge cranes installed at a rolling mill and a waste incineration plant of MVA Weisweiler GmbH & Co. KG.
The latter was fitted with igus products in 2009 and has been working smoothly ever since.
“It’s of great benefit here that the chains clean themselves,” says Stephan Runke of MVA Weisweiler.
“The dirt particles simply fall away when the chain moves.”
Comprehensive practical experience as the basis for new developments
After eight years of experience with the roller energy chain, igus introduced the “P4” to the market. The P4 is characterised by operation that features considerably less noise and vibration due to the double-roller design. As a result, it has been possible to increase the service life of the system.
The P4 is specifically designed for high travel speeds of over 10m/s and high fill weights of up to 50 kg/m. The upper rollers do not run one above the other but are offset by the lower run and are supported by comb-like autoglide crossbars.
One of the goals of the P4 system was to achieve special stability at high speeds and acceleration. The links therefore incorporate a double stop-dog system, and tight tolerances result in an almost clearance-free motion that enables high acceleration.
Linear gantry dynamics were also a top priority for GROB-Werke GmbH & Co. KG in Mindelheim, which has used igus low-maintenance P4 roller energy chains since 2011.
“Our linear gantries usually operate in three shifts, six days a week,” says Peter Vogl, director of construction and development at GROB-Werke.
“It depends on extremely robust components in all areas. Machine or plant downtime simply can’t occur.”
Vogl says the P4’s achieved dynamics, whereby the linear gantry is twice as fast as the previous model, are particularly noteworthy. To date, there have been no issues with the system.
Equipped for the digital future
Thanks to ongoing research, igus developers have been able to further optimise the roller energy chain in order to significantly increase plant safety and availability. A current example is the “P4.1”, which features a bearing point for pivoting in every connection of the chain links.
This has now been re-equipped with a maintenance-free igus tribo-polymer plain bearing, which more than doubles service life. Container cranes in ports can now achieve a service life of 15 years or more, or 20,000-plus operating hours, with low maintenance and high reliability.
The P4.1 can also be equipped with smart monitoring sensors, with a wear sensor for newly installed plain bearings. From a defined wear limit, this can issue a signal to the igus “icom” communication module, making it possible to plan maintenance in advance.
Trustworthy partnership at all levels
The close cooperation with the customer doesn’t end with the completion of the system. Treotham undertakes inspection and maintenance of igus energy chain systems for customers in Australia and New Zealand.
In customer-specific maintenance contracts, maintenance costs are waived for the first five years of ownership, and this cost transparency makes possible the highest planning reliability.
There is also an installation service for retrofitting and upgrading existing systems.
Customers also benefit from the world’s largest test laboratory in the industry, operating on more than 3,800 square metres, which includes a 1,000-metre outdoor testing facility.
Against this backdrop, it’s not hard to see why other industries have chosen igus’s roller energy chains. Customers in any industry can benefit from the solutions and related products once exclusively developed to meet the demands of the crane industry.
Roller energy chains, along with the entire igus product line, are available now from Treotham.
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