A radial gap superconducting magnetic bearing that takes advantage of a high-order multipolar magnetic field with revolution symmetry and at least a superconducting body to establish stable levitation minimizing the amount of superconducting material required, therefore reducing its cost and enhancing the performance of the bearing.
1. A non-contact bearing structure comprising a) A rotor provided with a.1) An inner set of two or more permanent magnets axially magnetised with symmetry under rotation, their magnetisation direction being opposite between contiguous permanent magnets. a.2) An outer set of two or more ring permanent magnets axially magnetised with symmetry under rotation, their magnetisation direction being opposite between contiguous permanent magnets and being the outer set concentrically aligned with the said inner set of permanent magnets. b) A stator located between said inner and outer sets of permanent magnets of the rotor, provided with at least a superconducting part. 2. A non-contact bearing structure comprising a) A stator provided with a.1) An inner set of two or more permanent magnets axially magnetised with symmetry under rotation, their magnetisation direction being opposite between contiguous permanent magnets. a.2) An outer set of two or more ring permanent magnets axially magnetised with symmetry under rotation, their magnetisation direction being opposite between contiguous permanent magnets and being the outer set concentrically aligned with the said inner set of permanent magnets. b) A rotor located between said inner and outer sets of permanent magnets of the stator, provided with at least a superconducting part. 3. A bearing structure according to claims 1 or 2 also comprising a) A plurality of outer sets of two or more permanent magnets axially magnetised with symmetry under rotation, their magnetisation direction being opposite between contiguous permanent magnets and being the outer sets concentrically aligned with the said inner set of permanent magnets. b) A plurality of superconducting bodies, comprising each of them at least a superconducting part, located between two of the sets of permanent magnets. 4. A bearing structure according to any of the previous claims being the magnets of the outer set or sets characterized by being their north poles on the same planes as the north poles of the corresponding magnets of the inner set. 5. A bearing structure according to any of the previous claims where the permanent magnets in the said inner set are ringshaped and where at least a superconducting part is located inside the hole of the inner set of permanent magnets. 6. A bearing structure according to any of the previous claims where there is at least one superconducting part surrounding, at least partially, the outermost set of permanent magnets. 7. A bearing structure according to any claim from 1 to 6 where one or more magnetic field generators are used in place of at least one of the permanent magnets. 8. A bearing structure according to claim 7 where at least one of the said magnetic field generators is a superconducting magnet. 9. A bearing structure according to claims 7 or 8 where at least one of the said magnetic field generators is a persistent current. 10. A bearing structure according to any of the claims from 7 to 9 where at least one of the said magnetic field generators is an electromagnet. 11. A bearing structure according to any of the previous claims where the preferred superconducting material is ReBa2Cu3Ox/Ag where Re represents a rare-earth chemical element like Yttrium (Y), Lanthanum (La) or Samarium (Sm). 12. A bearing structure according to any of the claims from 1 to 11 where there is at least one spacer mainly composed of a magnetisable material placed between two contiguous permanent magnets in a set. 13. A bearing structure according to any previous claim where cooling means are provided for refrigeration of the superconductors.