New energy management from igus for SCARA robots in cleanrooms

The Clean SCARA Cable Solution ensures a particle-free power supply even during highly dynamic movements. (Source: igus GmbH)

igus introduces a new energy supply system for SCARA robots in cleanrooms: The Clean SCARA Cable Solution consists of tribologically optimized high-performance plastics and operates nearly particle-free even during high-speed applications according to ISO Class 2. Additionally, the system offers high stability and user-friendliness compared to traditional corrugated hoses.

The Hollywood blockbuster Deep Impact: A comet with a diameter of 2.5 kilometers races toward Earth, strikes, and causes worldwide destruction. A worst-case scenario, which electronics manufacturing can also relate to—albeit on a different scale. Because here, tiny particles invisible to the naked eye are the comets that ruin electronic components, semiconductors, and displays. Accordingly, it is crucial that machines and systems operate with minimal friction and do not contaminate the surrounding air. Not an easy task, especially with so-called SCARA robots, which resemble a human arm and move rapidly across four axes—with cycle times well under one second. There is always a risk that particles from hoses and pipes may loosen during high-speed applications. "Routing cables and hoses on the SCARA robot in a cleanroom is actually a science in itself. Fast movements are pure stress for the material, which causes abrasion and the release of unwanted particles," confirms Matthias Meyer, Head of the triflex and Robotics Business Unit at igus. For this reason, igus expanded the 2020-developed energy supply system SCARA Cable Solution with a variant suitable for cleanrooms. "The new Clean SCARA Cable Solution is a cleanroom-compatible energy supply for high-speed applications—reliable, compact, easy to operate, and quick to retrofit," says Meyer.

ISO Class 2: barely any particles in the ambient air even during the wildest movements

The core of the new cleanroom energy supply is the e-skin soft, a modular energy chain that guides cables and hoses in an arc from the robot's vertical arm to the end effector. Its flexible upper and lower shells can be assembled into a sealed, dust- and water-proof pipe. This ensures that particles from the cables and hoses do not escape into the environment—even during vigorous movements. "To reduce stress on the cables and increase their durability, we have mounted the connections at the fixed point and the drive with rotating bearings," explains Meyer. "This is the special feature of the energy supply system. At the same time, the rotary bearings are designed to be nearly particle-free even during the most dynamic movements." The e-chain itself is also particularly abrasion-resistant—thanks to tribologically optimized high-performance plastic. This is confirmed by ISO certification from experts at the Fraunhofer Institute. The Clean SCARA Cable Solution has achieved ISO Class 2. This means that the energy supply is so abrasion-resistant that in operation, no more than 100 particles up to 0.1 micrometers in size are found per cubic meter of air. For comparison: an average sheet of paper is 80 micrometers thick, 800 times thicker.

Clean SCARA Cable Solution as an alternative to traditional corrugated hoses

With the new energy supply system, igus offers an alternative to traditional corrugated hoses, which, in addition to being suitable for cleanrooms, provide two other advantages. First: Thin corrugated hoses, mainly used with SCARA robots, have little inherent stiffness and can bend quickly. The lack of support that absorbs torsion also causes the hoses to tear quickly. "Unlike corrugated hoses, the Clean SCARA Cable Solution supports itself and features a unique rotary bearing. This makes it ideal for short cantilevered lengths and highly dynamic applications," says Meyer. "Particularly when lateral forces are applied, the oval geometry of the chain offers additional stability." The second advantage over corrugated hoses: thanks to the Zipper principle, the Clean SCARA Cable Solution can be opened as easily as a zipper. This allows users to insert cables and hoses quickly. For additional protection, an optional internal partition is available, which is also not possible with corrugated hoses. "If desired, the customer can receive the new energy chain for cleanrooms pre-assembled with chainflex cables as a complete system," adds Meyer. "Over 900 highly flexible cables with IPA Class 1 are available for this purpose."