Design and operating principles of a magnetically suspended ceiling actuator with fail-safe operation

摘要

This paper presents the design and operating principles of a magnetically suspended ceiling actuator when it is used as a planar conveyor system. The presented ceiling actuator consists of a translator which is magnetically suspended under and propelled in the plane below a stationary frame, called the ceiling. Four linear actuators comprise the translator and provide a limited stroke in the xy-plane. Because permanent magnets and iron are employed inside the linear actuators, a passive attraction force is created between the translator and ceiling which provides fail-safe operation. The linear actuators are optimized with the objective to minimize the ohmic losses when the translator is accelerated. Furthermore, it is shown that depending on the level of acceleration, the minimum dissipated power is obtained at different airgap lengths.