Abstract: 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.

Abstract: A multi degree-of-freedom electromagnetic machine includes an outer case, an inner case, a stator, stator windings, a voice coil winding, a tilt magnet, a rotor, and rotor magnets. The inner case is disposed within an inner cavity of the outer case and is mounted to rotate relative to the outer case about one or more rotational axes. The stator is fixedly mounted within the inner case, and the stator windings are wound thereon. The voice coil winding is fixedly coupled to either the inner surface of the outer case or the outer surface of the inner case. The tilt magnet is fixedly coupled to either the outer surface of the inner case or the inner surface of the outer case. The rotor is rotationally mounted within the inner case and is operable to rotate, relative to the stator, about a rotational axis.

Abstract: A multi-degree-of-freedom electromagnetic machine includes a spherical structure, a first coil, a second coil, a non-magnetic structure, and a Halbach array. The spherical structure has a first axis of symmetry, a second axis of symmetry, and a third axis of symmetry, and the first, second, and third axes of symmetry are disposed perpendicular to each other. The first coil is wound on the spherical structure about the first axis of symmetry, and the second coil is wound on the spherical structure about the second axis of symmetry. The non-magnetic structure is spaced apart from, and at least partially surrounds, the spherical structure. The Halbach array is mounted on the non-magnetic structure and includes N-magnets, where N is a multiple of 4. The spherical structure and non-magnetic structure are mounted to allow relative rotation between the non-magnetic structure and the spherical structure.

Abstract: A stepper motor includes a rotor, a stator, a plurality of stator windings, and a plurality of permanent magnets. The permanent magnets are coupled to the outer surface of the rotor and are spaced apart from the plurality of stator poles, and each permanent magnet is shaped like an arc having an arc length and is circumferentially spaced apart from two adjacent permanent magnets by a spacing angle. In some instance, the arc length of each permanent magnet is equal, and the spacing angles are not all equal. In other instances, the arc length of two or more of the permanent magnets is unequal to the arc lengths of the other permanent magnets, and the spacing angles are not all equal.

Abstract: 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.

Abstract: A two degree-of-freedom motor includes a stator, a plurality of stator windings, a rotor, a shaft, a limited angle torque motor, and a spring. The stator has a main body and a plurality of stator poles. The stator windings are wound around the stator poles. The rotor is spaced apart from the stator and includes a plurality of magnets and is configured to rotate about a first rotational axis. The shaft is coupled to the rotor and is rotatable therewith and and has a shaft first end and a shaft second end. The limited angle torque motor is coupled to the shaft first end, and is operable to supply a torque that causes the shaft, the rotor, and the stator to rotate about a second rotational axis that is perpendicular to the first rotational axis. The spring is fixedly mounted and is coupled to the limited angle torque motor.

Abstract: A two degree-of-freedom motor includes an inner stator, a plurality of inner stator windings, an inner rotor, an outer stator, a plurality of outer stator windings, an outer rotor, and a shaft. The inner rotor is spaced apart from, and at least partially surrounds, the inner stator, and includes a plurality of magnets. The outer stator is spaced apart from, and at least partially surrounds, the inner stator and the inner rotor. The outer rotor is spaced apart from, and is disposed between, the inner rotor and the outer stator, and has a plurality of outer rotor projections. The shaft is coupled to the inner rotor and the outer rotor.

Abstract: A multi degree-of-freedom electromagnetic machine includes an outer case, an inner case, a stator, stator windings, a voice coil winding, a tilt magnet, a rotor, and rotor magnets. The inner case is disposed within an inner cavity of the outer case and is mounted to rotate relative to the outer case about one or more rotational axes. The stator is fixedly mounted within the inner case, and the stator windings are wound thereon. The voice coil winding is fixedly coupled to either the inner surface of the outer case or the outer surface of the inner case. The tilt magnet is fixedly coupled to either the outer surface of the inner case or the inner surface of the outer case. The rotor is rotationally mounted within the inner case and is operable to rotate, relative to the stator, about a rotational axis.

Abstract: A multi-degree-of-freedom electromagnetic machine includes a spherical structure, a first coil, a second coil, a non-magnetic structure, and a Halbach array. The spherical structure has a first axis of symmetry, a second axis of symmetry, and a third axis of symmetry, and the first, second, and third axes of symmetry are disposed perpendicular to each other. The first coil is wound on the spherical structure about the first axis of symmetry, and the second coil is wound on the spherical structure about the second axis of symmetry. The non-magnetic structure is spaced apart from, and at least partially surrounds, the spherical structure. The Halbach array is mounted on the non-magnetic structure and includes N-magnets, where N is a multiple of 4. The spherical structure and non-magnetic structure are mounted to allow relative rotation between the non-magnetic structure and the spherical structure.

Abstract: A stepper motor includes a rotor, a stator, a plurality of stator windings, and a plurality of permanent magnets. The permanent magnets are coupled to the outer surface of the rotor and are spaced apart from the plurality of stator poles, and each permanent magnet is shaped like an arc having an arc length and is circumferentially spaced apart from two adjacent permanent magnets by a spacing angle. In some instance, the arc length of each permanent magnet is equal, and the spacing angles are not all equal. In other instances, the arc length of two or more of the permanent magnets is unequal to the arc lengths of the other permanent magnets, and the spacing angles are not all equal.

Abstract: A multi-stage spherical motor includes an inner stator, an outer stator, a rotor, and magnets. The inner stator has a plurality of inner stator windings wound thereon. The outer stator is spaced apart from and at least partially surrounds the inner stator, and has a plurality of outer stator windings wound thereon. The rotor is disposed between the inner stator and the outer stator and is configured to rotate about a plurality of perpendicular axes. The rotor has an inner surface and an outer surface. An inner array of magnets is coupled to the inner surface of the rotor, and an outer array of magnets coupled to the outer surface of the rotor. In some embodiments, a multi-stage spherical motor includes an inner rotor, an outer rotor, a stator, inner stator coils, and outer stator coils.