In crane technology, simple “off-the-shelf” solutions cannot always be adapted to new applications, as the requirements are always different. Large temperature fluctuations, severe vibration or movements of the entire steel construction have to be taken into account when new equipment or a retrofit of an existing crane is planned.
The motion plastics specialist igus has now equipped its 1 000th STS crane (ship-to-shore) with an energy chain system made of plastic, thus demonstrating that the trend towards lightweight, long-lasting components is now state-of-the-art all over the world. Theo Diehl, Head of Industry Management Cranes, who was directly involved in many of these 1 000 projects explains, “For us, the big breakthrough was the development of the rolling energy chain, which we installed to supply power to the trolley of our first STS crane in 2000.
‘‘By using a roller, the coefficient of friction on long travels drops dramatically, when the upper run of the chain runs on the lower run. Thereby, up to 57 percent of the required drive energy can be saved while moving the energy chain system. Noise levels are also significantly reduced.”
Over a period of many years
“Then in 2004, the heavy duty version of the roller energy chain was launched onto the market”, explains Theo. “It was strengthened in many ways and its stability and expected service life were drastically improved as a consequence.
“In 2008, the ‘P4’ roller energy chain was launched onto the market based on our experience in the preceding eight years. It is characterised by the fact that it operates with considerably less noise and vibration due to the double-roller design and as a result it has been possible to increase the service life of the system.”
Intelligent devices that predict the required component replacement date during ongoing operation and thus increase fail-safety, round off the portfolio. This includes, for example, the new and improved EC.M module, which is mounted on the moving end of the chain and automatically records acceleration, speed, temperature and the number of cycles completed.
Other examples are the EC.W wear sensor, which measures the wear on the e-chain and thus makes it possible to determine the remaining service life, and the new EC.RC (e-chain Run Control), which was introduced in 2017 and monitors the operating status of the chains, especially in guide troughs where long travels are involved.
Sensors measure and check the position of the energy chain. In this way, the machine is prevented from continuing to operate when mechanical faults occur; meaning that total loss of the chain or an electrical shutdown (for example, due to cable damage) are a thing of the past.