METHODS FOR DETECTING STEPOUT OF MAGNET COUPLING AND FOR RESTARTING IT AFTER STEPOUT

摘要

PURPOSE:To enable detecting surely the generation of a stepout of a magnet coupling composed of driving side and driven side magnets by judging that said magnet coupling has stepped out, when the number of revolutions of a motor driving said driving side magnet to rotate is more than a given value. CONSTITUTION:Directly under the bottom of an incubation tank 1, a driving side magnet 3 driven by a motor 2 to rotate and a driven side magnet 5 with a fixed agitating element 4 are provided in opposition to each other. On said driving side magnet 3 and driven side magnet 5, N and S poles are alternately arranged at equal pitches all over circumferentially. To the motor 2, electric current is supplied according to a torque necessary for rotating the driving side magnet 3. When the number of revolutions of said motor 2 is more than a given value during operation, the driving side magnet 3 and the driven side magnet 5 are judged to have stepped out so that the motor 2 is stopped. After that, the motor 2 is restarted with a low number of revolutions.