Satellite momentum wheel
AssigneeSociete Nationale Industrielle Aerospatiale
InventorPierre Poubeau
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Abstract
The invention provides a satellite momentum wheel with passive magnetic centering means, between a stator and a rotor comprising at least one passive radial magnetic centering device, at least one axial magnetic centering device slaved to an axial velocity sensor and to an axial position sensor, at least one centering motor-generator unit having a magnetized rotor and a stator with toroidal windings switched by an angular rotation position sensor, at least one damping device, two emergency taper pivots for safe centering of the axial mounting of the rotor one of which is possibly in contact with a doped-polyamide step bearing on the stator, and interconnecting means between the wheel rim and the axis of said pivots employing a so-called coated arrayed-thread type cycloprofile structure.
Claims14
A magnetically suspended momentum wheel for satellites, including a stator within which are disposed:
- a rotor having a rotation shaft with back-up anti-friction bearings capable of selectively bearing against associated safety abutment means;
- a sensor for sensing the axial velocity and a sensor for sensing the axial position of said rotor in relation to said stator;
- at least one passive magnetic radial centering means formed by at least two coaxial magnet cores with alternating axial magnetic fields that are mounted on said rotor and are included, on either side, between two coaxial magnetic cores rigidly connected to said stator and the complementary axial magnetic field of which closes upon said stator through a yoke;
- at least one active magnetic axial centering means formed by at least one magnetic core with a radial field mounted on said rotor and disposed opposite at least one circular coil fast with said stator and receiving correction signals from said axial velocity sensor and said axial position sensor;
- at least one damping means at one end of said rotor and formed by a conducting disc connected to said stator and included between toroidal magnets angularly rigid with said rotor;
- at least one switchable motor-generator formed by at least one alternatingly magnetized magnetic core connected to said rotor and included, on either side, between windings connected to said stator and wound over a ferromagnetic toroidal core;
- whereby those turns of said windings which lie in the air gap engender either electromagnetic forces enabling said magnetic core to rotate through successively switched activation of said toroidal windings subjected one after the other to the same continuous magnetic field, and a unidirectional induced current when said magnetic core is continuously rotated and said toroidal windings are switched in succession after being subjected one after the other to the same continuous magnetic field.
Dependencies are inferred from the claim text.