e-spool cable guide for orbital friction-stir welding system with 660° rotation

What was needed: Two e-spools (SPHD2) for transmitting energy, control signals and data to a rotating unit with a movement range of up to 660°

Requirements: Cost-effective solution, simple integration, low maintenance and proven in applications with rotating movements

Industry: Machine tool manufacturing

Success for the customer: The use of the e-spool provided a reliable and elegant solution to the rotation requirement. The solution is low maintenance, minimises noise emissions and was decisive for the successful design of the orbital welding system.

ESA Technologies AG, a company in the energy technology sector, develops and manufactures machines and systems for the production of gas-insulated cables (GIL cables). These cables are used by large companies such as Siemens, GE or Hitachi and are essential for modern high-voltage transmission networks. The newly developed friction-stir welding system from ESA Technologies AG is specially designed for welding flanges to the ends of GIL cable tubes. It works with the so-called FSW process, which reduces smoke gases and noise emissions, the need for shielding gases or additives and energy consumption compared to conventional welding methods. The system can be used to process pipes with a diameter of up to 590mm, a wall thickness of 8mm and a length of 12 metres.

A central component of the system is a rotating unit that has to perform a rotation of up to 660° while simultaneously transmitting energy, control commands and sensor data without interference. This unit contains three servo drives, a 5.5kW lead screw drive, a surveillance camera and several measuring elements and sensors. Approx. 13,000 - 15,000 cycles are carried out per year. A rotating cable guide was sought for the reliable transmission of energy and data. A spring-mounted cable drum with a slip ring was initially considered for this purpose, but failed due to the high costs, the increased maintenance effort and the complex design.

When the idea for the friction-stir welding system was born, considerations for optimal cable guidance with the customer began at an early stage. The challenges of rotating energy and data transmission were finally solved by using two e-spool spring-loaded cable drums (SPHD2). The e-spool is a slip ring-free spring-loaded cable drum that enables simple, flexible and reliable transmission of energy, control and data in the application. It replaces slip rings, which allow continuous rotation but are often associated with higher costs, more maintenance and increased design complexity.

A special feature of this application is the movement of cables onto a rotating unit that revolves around a centre while simultaneously undergoing rotation of up to 660°. The e-spool ensures that the cables are always safely guided in the energy chain. Despite the complex requirements, the solution was easy to integrate. The low-maintenance operation and the proven reliability of the e-spool were decisive for the success of this project.

Overall, the e-spools contributed to the successful implementation of the system by enabling simple, elegant and cost-efficient cable guidance in the friction-stir welding machine.