Redundant active electromagnetic bearing

A redundant active electromagnetic bearing for supporting a movable member, comprising:

• a first set of electromagnet coils wound on an armature having double-pole parts and a second set of electromagnet coils would on said armature, a first and a second detection device for sensing the position of the movable member, a first control circuit connected to said first detection device and capable of being connected to said first set of coils for controlling the supply of said first set of coils in response to signals delivered by the first detection device in order to keep the movable member in a predetermined position, a second control circuit connected to said second detection device and capable of being connected to said second set of coils for controlling the supply of said second set of coils in response to signals delivered by the second detection device in order to keep the movable member in a predetermined position, and switch-over means being provided for connecting either the first set of coils with the first control circuit or the second set of coils with the second control circuit in response to a control signal, wherein the first and the second sets of coils are so placed on said armature that on each double-pole part of said armature are wound one coil of the first set and one coil of the second set and that the successive coils of the first set are all wound in the same direction whereas the coils of the second set which duplicate the coils of the first set are alternately wound in the same direction and in opposite directions with respect to the corresponding coils of the first set.