Magneto-Mechanical Design of an Electromagnetically Actuated Coaxial Magnet Coupling for Fault Protection

This paper presents the design process for an electromagnetically actuated coupling disconnection system relying on contactless torque transfer. The device can replace existing mechanical and electromagnetic clutches to provide enhanced protection against over torque conditions resulting from faults in the coupled machines. The novel disconnection system contains a coaxial magnetic coupling (CMC) that can be fully disengaged via an electromagnetic actuator. This system configuration improves the fault performance of magnetic couplings and reduces the losses and maintenance requirements associated with other clutch designs. The end result is a more reliable and versatile coupling solution that can be used in a broad range of machine applications. The design and optimization process builds upon existing knowledge of CMC design to produce a practical device that can transmit a maximum torque of 100 Nm and rotate at a maximum speed of 20,000 RPM. The electromagnetic actuator is tested to ensure the system is capable of disengaging the coupling. An investigation is made into the axial forces present in a CMC when the magnets are separated. It is concluded that decoupling a CMC is practical and achievable with the presented electromagnetic actuator design.