Passive magnetic bearing and rotating machineries integrating said bearing, including energy production turbines

A passive magnetic bearing comprising:

• a first ring element having an axial depth and being formed of magnetic material, the first ring element further having a Halbach array, the Halbach array being constant about a circumference of the first ring element;
• a second ring element having an axial depth and being formed of magnetic material, the second ring element being substantially concentric with the first ring element and being positioned relative to the first ring element within an operating range defined in an axial direction, the second ring element having:
• a first Halbach array extending angularly over a first set of at least one angular region of the second ring element;
• and
• a second Halbach array extending angularly over a second set of at least one angular region of the second ring element;
• wherein the first ring element is rotatable about the second ring element;
• and
• wherein the magnetic interaction from the Halbach array of the first ring element with the first and second Halbach arrays of the second ring element, when positioned relative to each other within the operating range defined in the axial direction, defines a combined force curve having:
• an axial component in the axial direction substantially matching a predetermined target axial force curve;
• and
• a radial component in the radial direction at a predetermined angular position substantially matching a predetermined target radial force curve.