Rotor and reluctance motor

A rotor, comprising:

• a shaft configured to rotate about the central axis;
• and
• a rotor core fixed to the shaft,
• wherein the rotor core has a plurality of flux barriers formed side by side in a radial direction of the rotor core, each of the flux barriers ranging from a certain portion to another portion of an outer circumferential surface of the rotor core,
• each of the flux barriers has:
• a plurality of bridges that include a bridge forming a part of the outer circumferential surface of the rotor core at opposite ends thereof in a longitudinal direction thereof;
• and
• one or more barrier regions that have a lower permeability than a portion other than each of the flux barriers in the rotor core between the plurality of bridges,
• a permanent magnet is provided in at least one of the barrier regions,
• a magnetizing direction of the permanent magnet is directed in a direction that intersects a longitudinal direction of each of the flux barriers at a position at which the permanent magnet is provided, and
• when a permeability of a region where the permanent magnet is not present in the barrier region is defined as μ0,
• a cross-sectional area of the permanent magnet in a plane that is orthogonal to an extending direction of the shaft is defined as SM,
• a residual magnetic flux density of the permanent magnet is defined as Br,
• a recoil permeability of the permanent magnet is defined as μre,
• an arithmetic mean between a minimum and a maximum of a thickness of the bather region is defined as tFB, and
• a sum of widths of all the plurality of bridges is defined as wB,
• a value of (μ0×SM×Br)/(μre×tFB×wB) is within a range between 1.2 and 3.0.