Effective energy - Data transmission in the crane system

Energy chains play off its technical and economic strengths

In the crane system, the requirements on the operating safety are especially high due to the long travels. Expensive shut downs and downtimes must be avoided in any case. It has been shown in various national and international projects that energy chain systems have become furthermore indispensable when it comes to power supply systems for moving loads.

Projects in Asia and Europe

In crane systems, ready assembled energy chains, the so-called ReadyChain®, are almost exclusively used. The customer profits from it in many ways. The system is delivered to the installation site, saving considerable time during installation. Moreover, installation errors can be excluded to a large extent. With experiences from an application in Malaysia with a travel distance of nearly 450 m, the company installed energy chain systems on twelve ship-to-shore cranes in Asia. The travel length of these cranes comes up to 500 m. The length of the energy supply system amounts to 260 m. The energy chain systems installed in a shaft were equipped with stainless steel guide troughs and provided with a traversable top cover system.

Energy chains

Ready assembled energy chains save a lot of time during installation and excludes installation errors to a large extent.

 

The trolley drive in ship-to-shore cranes moves at a speed of 250 m/min and uses a Rol E-Chain® for the energy and data transmission. For this high speed trolling, additional drives or a control system are not required for the chain. Moreover the weight is lower than any conventional system. The crane builder can thus save drive power for the trolley and system weight for the crane girder. The crane builder decided on the Chainflex® fiber glass cable for data transmission. This solution is the safest kind of data transmission - without EMC disturbances - and thus avoids potential loss of data. This extremely light and flexible cable plays off its strength especially in applications with high loads. Another project, retrofitting of a ship unloader, was undertaken in Netherlands. The travel distance of the carriage amounted to 106 m at a speed of 240 m/min. The wagon is driven by a motor and is equipped with a series of energy and data cables. The cable weight amounts to over 50 kg/m. A system was developed as solution for the supply of the carriage that doesn't require any additional drive and thus offers utmost operating safety.

Heavy cables guide safely

In the Netherlands, igus uses two newly developed heavy duty energy chains. When heavy cables have to be guided over long travel stretches, the chains for these extreme loads are used. They have been further developed in three points to raise their stability still more. On the one hand, the bearing surfaces have been extended by 120% for the pin-hole connections. The diameter of the connection holes of the chain links were raised from 40 to 45 mm, and the pin length doubled from four to eight millimeters. Stability and service life of the energy chains increase through the thus essentially enlarged bearing surfaces. Thus it possesses the capability to bear higher tensile and shear forces. Moreover the thickness of the side plates have been raised from 22 to 29.5 mm. With unaltered inner height (80 mm) and outer height (108 mm), the chain also operates quietly and with stability with high additional loads.

Crane system

Travel distance in the wharfage Expensive shut downs and downtimes can be avoided thanks to rugged energy chain systems.

 
Online monitoring for large scale plants for energy chains

For the ship-to-shore major project, igus® has additionally installed a diagnosis tool. The "remote condition monitoring system" monitors the displacement forces of the energy chains and assists in preventing damages and stoppages. The pressure and tensile strength data are compared four times per second with a value fixed individually in advance. In case an error occurs, alarm signals are transmitted immediately and automatically via SMS and e-mail. They can then be analyzed at any required location. Stored data can be retrospectively analyzed for three months. The system opens completely new potentials in maintenance and fault diagnosis. So far it is used in crane drives. It has not yet been implemented on the trolley drives, but it's just a matter of time.

Technical data:

- Travel up to 500 m
- Length of the E-Chain® up to 260 m
- V max trolley drive 250 m/min
- Cable weight >50kg

More on applied products here
Further interesting applications from extremely diverse areas can be found here.