An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic thrust bearing, wherein the hybrid magnetic thrust bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

A radial stabilizer is provided for stabilizing levitation passive bearing elements against lateral displacements. The stabilizer provides a means to introduce anisotropy in the radial stiffness of the stabilizer. The presence of anisotropic stiffness has a strongly stabilizing effect on whirl-type rotor-dynamic instabilities. The stabilizer design also provides a means for continuously monitoring the state of health of the rotor by signaling the onset of changes of balance that would be expected to precede any major failure.

A magnetic suspension bearing (10; 30; 40; 50) is described comprising a part rotatable about a rotation axis and a fixed part, and two elements made of ferromagnetic material, one integral with the rotatable part and one with the fixed part. The two elements are closely placed, separated by an air gap, and have axial symmetry with respect to said axis. There is a magnetic flux generator for generating a magnetic flux inside the two elements. The two elements have such a shape that the magnetic flux, flowing inside the two elements, describes in space a torus and passes from one element to the other through the air gap along a direction orthogonal to the direction of a load applied to the bearing. This configuration ensures high support strength for the bearing while being a simple structure to be built.

An electric submersible pump (ESP) assembly. The ESP assembly comprises an electric motor, a centrifugal pump, and a hybrid magnetic thrust bearing, wherein the hybrid magnetic thrust bearing is disposed inside the electric motor or disposed inside the centrifugal pump.

A pump may include a stator, a rotor, and an impeller. The stator may include one or more electromagnets and one or more permanent magnets. The rotor may include an armature, one or more complementary permanent magnets, and a pull magnet configured to position the rotor in an axial direction. The rotor may be disposed within the stator. The complementary permanent magnets and the one or more permanent magnets of the stator may create magnetic bearings. The armature may be aligned with at least one of the electromagnets of the stator and configured to rotate the rotor with respect to the stator. The impeller may be coupled to the rotor.

A pump may include a stator, a rotor, and an impeller. The stator may include one or more electromagnets and one or more permanent magnets. The rotor may include an armature, one or more complementary permanent magnets, and a pull magnet configured to position the rotor in an axial direction. The rotor may be disposed within the stator. The complementary permanent magnets and the one or more permanent magnets of the stator may create magnetic bearings. The armature may be aligned with at least one of the electromagnets of the stator and configured to rotate the rotor with respect to the stator. The impeller may be coupled to the rotor.

A magnetic device for centring a shaft on a predetermined axis in a clockwork movement includes at least one first magnetic bearing provided with a magnet to exert an attractive force on a first ferromagnetic end pivot of the shaft. The first magnetic bearing includes a central part made of soft ferromagnetic material mounted between the magnet and the first end pivot of the shaft. The central part is positioned centrally in a washer made of non-magnetic material so as to centre the magnetic field flux generated by the permanent magnet through the central part in order to magnetically attract the first end pivot of the shaft on the predetermined axis. The diameter of the central part can be identical to, or 0 to 20% less than, or 0 to 20% greater than, the diameter of the first end pivot.

A magnetic suspension bearing (10; 30; 40; 50) is described comprising a part rotatable about a rotation axis and a fixed part, and two elements made of ferromagnetic material, one integral with the rotatable part and one with the fixed part. The two elements are closely placed, separated by an air gap, and have axial symmetry with respect to said axis. There is a magnetic flux generator for generating a magnetic flux inside the two elements. The two elements have such a shape that the magnetic flux, flowing inside the two elements, describes in space a torus and passes from one element to the other through the air gap along a direction orthogonal to the direction of a load applied to the bearing.

This configuration ensures high support strength for the bearing while being a simple structure to be built.

An axially compliant rolling bearing for precision motion stages having a stage, at least one bearing member slidably disposed along a rail, and a compliant joint interconnecting the at least one roller bearing to the stage. The compliant joint is sufficiently compliant to permit movement of the stage in the axial direction while remaining stiff in other directions orthogonal to the axial direction.

A rolling bearing device includes a bearing portion and a power generation portion. The power generation portion has a plurality of projecting portions provided on an outer ring spacer, a pair of core members provided on an inner ring spacer, a magnet, and a coil. The power generation portion generates an induced current in the coil as the projecting portions pass in the vicinity of first side end portions of the core members during rotation. There are two different loop paths along which magnetism generated by the magnet flows: a first loop path formed when the projecting portions are close to the first side end portions of the core members; and a second loop path formed when the projecting portions and the first side end portions of the core members are away from each other.