MTU Aero Engines

“Our goal was to replace the established manual job because the sheer complexity of the tightening process meant that it was becoming increasingly prone to error,” says Nico Vohse, who had the idea for the project and launched it. The project team set out to find an optimum, forward-thinking solution. But instead of simply replacing one manual process with another, MTU decided to switch to an automated process based on industrial robots. This promises to be a sound investment in the future: as this new solution offers significantly greater precision and can be adapted to other models of rotor, other MTU sites also stand to benefit in the medium term.

Arduous and unergonomic manual labor eliminated

Together with 3D.aero—an automation solutions provider specializing in solving problems particular to the aviation industry—the Hannover team developed a solution that combines many of the benefits of digitalization and Industry 4.0. It also happens to make life much easier for the employees who have to get the job done. It was advantageous that among the project team comprised several employees who had performed the task manually many times before, which meant they were very familiar with the hand movements and the obstacles involved. “In the past, mechanics would work in a less than ergonomic position bent over the rotor, ultimately using a mirror and a light to check whether the nuts were in the correct position,” says Ingo Scheele, the member of the project team responsible for first level support. “So when we switched to the robotic solution, we took the opportunity to eliminate these unergonomic processes while also introducing a camera system to help chart and document the tightening process,” Vohse says. Now, the camera system moves inside the rotor and documents whether everything there is up to scratch and if the nuts have been tightened correctly. The image data collected is then filed for future reference. This system’s added bonus is that the whole process can now be monitored remotely.

Flexibly adaptable to other compressor rotors

The solution achieved in collaboration with 3D.aero is highly customized—there was no real blueprint to follow or any similar process. “This is MTU’s first automated tightening robot in the field of assembly and disassembly to support such a specific maintenance area. But it won’t remain the only application we could imagine for this technology,” says Oliver Persuhn, who, together with Vohse, has been a part of developing the system from day one and is transferring it to standard operations.

Persuhn explains that MTU is striving to replicate the system’s more precise tightening and the improved time planning in maintenance processes for larger rotor series. “The current system variant can accommodate rotors with a diameter of up to 1.10 meters. And since the robot is equipped with quick-lock couplings, we can change out the tightening tool relatively easily and inexpensively.” What’s more, the technology provides an ideal basis for an automated measuring and assembly system for larger rotors and other automation projects. “At the end of the day,” says project team member William Xu, “our greatest achievement with the tightening robot is that we’ve brought industrial systems and IT closer together and torn down some big barriers in everything from incorporating IT to helping realize MTU’s Industry 4.0 strategy.” He adds that it’s now easier to integrate process data into the MTU ecosystem and to gather additional empirical data with a view to rolling out this lighthouse project at other sites further down the line.