A motor rotor includes an iron core. A mounting groove is recessed from an end surface of the iron core and extends in a direction from a middle of the iron core to an outer peripheral surface of the iron core. The motor rotor further includes a first magnet and a second magnet embedded in the mounting groove and arranged at an interval along an extension direction of the mounting groove. The first magnet is fixed at a radial outer side of the second magnet. A magnetization direction of each of the first magnet and the second magnet is perpendicular to the extension direction of the mounting groove. A coercive force of the first magnet being greater than a coercive force of the second magnet.

A motor rotor includes an iron core. A mounting groove is recessed from an end surface of the iron core and extends in a direction from a middle of the iron core to an outer peripheral surface of the iron core. The motor rotor further includes a first magnet and a second magnet embedded in the mounting groove and arranged at an interval along an extension direction of the mounting groove. The first magnet is fixed at a radial outer side of the second magnet. A magnetization direction of each of the first magnet and the second magnet is perpendicular to the extension direction of the mounting groove. A coercive force of the first magnet being greater than a coercive force of the second magnet.

A two degree-of-freedom brushless DC motor includes a stator, a rotor, a plurality of distributed stator windings, and a stator voice coil winding. The stator includes an inner stator structure and a plurality of arc-shaped stator poles. The inner stator structure includes a main body and a plurality of spokes that are spaced apart from each other to define a plurality of stator slots. Each arc-shaped stator pole is connected to a different one of the spokes. The rotor is spaced apart from the stator, includes a plurality of magnets, and is configured to rotate about a plurality of perpendicular axes. The distributed stator windings are wound around the plurality of spokes and extend through the stator slots. The stator voice coil winding is wound around the outer surfaces of the arc-shaped stator poles. The arc-shape and spacing of the stator poles define the stator as being spherically shaped.

A two degree-of-freedom brushless DC motor includes a stator, a rotor, a plurality of distributed stator windings, and a stator voice coil winding. The stator includes an inner stator structure and a plurality of arc-shaped stator poles. The inner stator structure includes a main body and a plurality of spokes that are spaced apart from each other to define a plurality of stator slots. Each arc-shaped stator pole is connected to a different one of the spokes. The rotor is spaced apart from the stator, includes a plurality of magnets, and is configured to rotate about a plurality of perpendicular axes. The distributed stator windings are wound around the plurality of spokes and extend through the stator slots. The stator voice coil winding is wound around the outer surfaces of the arc-shaped stator poles. The arc-shape and spacing of the stator poles define the stator as being spherically shaped.

A core piece that is circularly arranged to construct a stator core of an axial gap type rotary electric machine includes: a first member in a column form extending in an axial direction of the stator core; a second member in a plate form disposed on a first end side of the axial direction in the first member; and a third member in a plate form disposed on a second end side of the axial direction in the first member, the first member has a peripheral surface connecting with the second member and the third member, the second member has a protruding portion projecting outwardly from the peripheral surface of the first member, the third member has a protruding portion projecting outwardly from the peripheral surface of the first member, and the first member, the second member, and the third member are configured by an integrally molded green compact.

A core piece that is circularly arranged to construct a stator core of an axial gap type rotary electric machine includes: a first member in a column form extending in an axial direction of the stator core; a second member in a plate form disposed on a first end side of the axial direction in the first member; and a third member in a plate form disposed on a second end side of the axial direction in the first member, the first member has a peripheral surface connecting with the second member and the third member, the second member has a protruding portion projecting outwardly from the peripheral surface of the first member, the third member has a protruding portion projecting outwardly from the peripheral surface of the first member, and the first member, the second member, and the third member are configured by an integrally molded green compact.

A one-piece permanent magnet is provided for use in an electric machine. The permanent magnet comprises a groove having a depth d which is equal to the thickness of the permanent magnet. The groove has a meandering or helical course with a subsection having the form of the letter S or the letter Z.

A one-piece permanent magnet is provided for use in an electric machine. The permanent magnet comprises a groove having a depth d which is equal to the thickness of the permanent magnet. The groove has a meandering or helical course with a subsection having the form of the letter S or the letter Z.

A motor includes a housing including a housing base and a housing shaft portion that is provided on the housing base and extends in a direction along a rotation center axis, a motor stator that is disposed outward in a radial direction of the housing shaft portion, a motor rotor that is provided between the motor stator and the housing shaft portion, a bearing that is provided inward in a radial direction of the motor rotor and rotatably supports the motor rotor to the housing shaft portion, a sealing structure that is provided on an opposite side to the housing base in an axial direction of the motor rotor and seals between the motor rotor and the housing shaft portion, and a resolver that is configured to detect rotation of the motor rotor.

A motor includes a housing including a housing base and a housing shaft portion that is provided on the housing base and extends in a direction along a rotation center axis, a motor stator that is disposed outward in a radial direction of the housing shaft portion, a motor rotor that is provided between the motor stator and the housing shaft portion, a bearing that is provided inward in a radial direction of the motor rotor and rotatably supports the motor rotor to the housing shaft portion, a sealing structure that is provided on an opposite side to the housing base in an axial direction of the motor rotor and seals between the motor rotor and the housing shaft portion, and a resolver that is configured to detect rotation of the motor rotor.