The blades in compressors and turbines are subject to particularly high levels of stress and strain. The job of the blades is to convert fluid energy into mechanical energy. They ensure that aircraft engines generate the required thrust and that power plant generators produce sufficient electricity.
Repairing damaged components makes sound financial sense. The drawback with repair is that the processes involved are very complicated and elaborate. The individual work steps cannot be easily integrated into largely automated series manufacturing. Specialists process the workpieces by hand or with specially adapted machine tools. Depending on its size, it can take anything from a few hours to several days before a single blade is repaired. Or to give another example: on account of the strict quality assurance requirements in the aviation industry, it can often take two to three weeks before an individual rotating engine component can return to action.
The Fraunhofer Institute is developing an automated, robot assisted technique. Lending the researchers support were specialists from turbomachinery manufacturers such as MAN, MTU, Rolls-Royce, and Siemens. Together with further partners from business and research, the team not only managed to make individual process steps suitable for automation, they also developed a technique whereby a robot passes through several repair stations inside a single production cell. What is special about this technique is that the robot holds on to the component at all times and moves around to the individual stations in turn, which are arranged around it in an area of about 15 square meters. It cleans the component, measures its geometry, locates the faults, and carries out machining repairs.