June 2021

TECHNOLOGY n 17 www.drivesncontrols.com June 2021 A DUTCH machine-builder has developed a welding cell based on a cobot (collaborative robot) that makes it easier for manufacturers to automate the welding of small batches, to introduce new products, and to allow people and machines to work together safely. AWL-Techniek has collaborated with Omron to develop the Qube cell, which has two key differences from conventional welding cells: it incorporates a manual turntable; and the welding is doen by a cobot. Until now, there have been two main methods of welding in manufacturing: robot cells; and manual welding. Robot cells are ideal for producing large batches, but lack flexibility and require strict safety conditions. This makes them inefficient and costly. Manual welding is ideal for small, changing batches, but needs qualified welders. The new Qube cell is aimed at manufacturers with requirements between these two extremes – typically, those producing series of 100 to 1,000 pieces and needing to change easily between different products. The cell resembles a conventional robot welding cell. It contains a cobot with a welding torch, the turntable which has two working sides, and a fume extractor, all enclosed by four walls. It can weld different types of metal, such as steel and aluminium, using MIG/MAG technologies. The turntable allows parts of different sizes to be welded together. Due to the fast and simple programming of the cobot – up to 45% faster than a traditional robot – there is no need for a specialist robot programmer. Instead, a qualified welder teaches and programs the cobot. The same cell can be used to weld a variety of products, allowing production personnel to continue working safely while a welding expert applies their knowledge to the next product. “With the increasing scarcity of qualified welding personnel, the cobot welding cell is ideal, especially for smaller production companies,”says AWL’s business developer, Thomas Modderkolk. The welding expert can assess new welds safely while in the cell with the cobot. After programming, other employees can continue the welding work and only need to control the supply of items to be welded. The manual turntable allows a welder to work at the same time as the cobot, potentially halving cycle times. The cobot welds with a repeatable accuracy of 0.1mm, ensuring consistent product quality – more consistent than welding by hand. Fewer parts are therefore rejected. Another attraction of the Qube is that it is compact, lightweight and self- contained, allowing it to be moved using a forklift or overhead crane from one part of a factory to another, depending on where it is needed. The only connection required is a power cable. As an independent system integrator, AWL uses different makes of robot in its machines. It found the Omron cobot attractive for the Qube application because its graphical programming makes it easy for almost anyone to use. Omron and AWL have entered into a global partnership to develop and distribute the cell.“Combining the knowledge and skills of both our companies has resulted in a product that can meet the needs of the customer in all areas,”says Stephan Pruiksma, innovation manager at Omron Benelux.“While AWL has expertise in the field of process improvement, Omron’s strength is at the component level. Together we can offer a powerful and unique cobot welding cell that boosts productivity, increases safety and makes employees more efficient.” www.awl.nl/qube Cobot welding cell targets manufacturers with short runs The cobot welder can be taught and programmed safely by welder inside the cell THEGERMAN automotive supplier Mahle is developing a magnet-free motor that, it claims, will operate with an efficiency of more than 95% at almost all operating points. The motor uses an inductive – and thus contact- and wear-free – technology to transmit power between its stationary and rotating parts. Mahle says that the asynchronous motor, which generates magnetic fields using excitation coils in the rotor, combines the strengths of different motor technologies in one product. It does not use any rare- earth materials, making it environmentally attractive, and offering advantages in terms of costs and resource security. “Our magnet-free motor can certainly be described as a breakthrough, because it provides several advantages that have not yet been combined in a product of this type,” explains Dr Martin Berger, Mahle’s vice- president of corporate research and advanced engineering.“As a result, we can offer our customers a product with outstanding efficiency at a comparatively low cost.” Energy is transmitted to the rotor via an alternating field. The energy is converted into DC to power the magnetic coils, avoiding the need for permanent magnets. The coils induce a magnetic field in the motor’s airgap, causing it to produce torque. Depending on the operating point, the field can be controlled easily – unlike PM machines, according to Mahle. The rugged motor technology is aimed mainly at automotive drivetrains and is said to be scalable, allowing it to be used in anything from small cars to commercial vehicles. It is expected to be a few years before the technology is commercially available. ‘Breakthrough’ motor combines strengths of different technologies