Design of Power Off Brake : Utveckling av testutrustning

Sammanfattning: The goal with this thesis is to find together with Saab Avionics Systems the correlation between applied current, air gap and forces that a brake with an electromagnetic release function have. This is achieved through theoretical calculations and practical tests.   At the moment the brakes are used in electromechanical actuators that are applied in aircraft flap systems. These brakes have been in Saab’s collection of products since a decade and to keep on being a competitive supplier they need to optimize their design process. However, there are difficulties regarding calculating the force of the magnetic field of these brakes since it is very complicated. To better understand how the design can be altered the current product Power Off Brake needs to be tested and analyzed.   The test equipment that was developed is designed so that the brake dimension, air gap and current can vary alongside a change of surrounding temperature. After a test in room temperature it was found that the test equipment had a margin of error about 10%. By testing Power Off Brake with the selected measuring method and test equipment Saab will get one step closer to better understand the relationship between theoretical calculations and practical tests. This can be used to reduce the safety margins when new brakes are to be developed since the test results provide insight about what happens when saturation in the material occur and how the brake perform in environmental conditions of an aircraft. Furthermore, the authors leave recommendations for continued work and suggestions for improved design.