Magnetic gearbox with flux concentration halbach rotors
AssigneePortland State University
InventorJonathan Bird
Life of this patent
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Abstract
This application relates to translating mechanical energy from a low-speed rotor to a high-speed rotor or vice versa in a magnetic gearbox. More specifically, this application discloses various embodiments of a coaxial magnetic gearbox with flux concentration Halbach rotors. In certain implementations, the device further comprises a circular back iron (or other ferromagnetic material) disposed concentrically along the axis of the cylindrical magnetic gearing device. In such embodiments, this flux concentration back iron (or ferromagnetic pole) improves the torque density and can also help retain the magnets in place.
Claims20
A cylindrical magnetic gearing device comprising:
- an outer cylinder having an outer circumference and an inner circumference, comprising:
- a first plurality of magnetic pole pairs disposed along the outer cylinder, wherein the first plurality of magnetic pole pairs extends radially between the inner circumference and the outer circumference of the outer cylinder;
- a second plurality of magnetic pole pairs disposed along the outer circumference of the outer cylinder, each respective pole of the second plurality of magnetic pole pairs being interspersed between respective poles of the first plurality of magnetic pole pairs, wherein the polarities of the second plurality of magnetic pole pairs are substantially orthogonal to the polarities of the first plurality of magnetic pole pairs;
- and
- a first plurality of ferromagnetic pole pieces disposed along the inner circumference of the outer cylinder and interspersed between respective poles of the first plurality of magnetic pole pairs;
- an inner rotor having an outer circumference and an inner circumference, comprising:
- a third plurality of magnetic pole pairs disposed along the inner rotor, wherein the third plurality of magnetic pole pairs extends radially between the inner circumference and the outer circumference of the inner rotor;
- a fourth plurality of magnetic pole pairs disposed along the inner circumference of the inner rotor, each respective pole of the second plurality of magnetic pole pairs being interspersed between respective poles of the third plurality of magnetic pole pairs, wherein the polarities of the fourth plurality of magnetic pole pairs are substantially orthogonal to the polarities of the third plurality of magnetic pole pairs;
- and
- a second plurality of ferromagnetic pole pieces disposed along the outer circumference of the inner rotor and interspersed between respective poles of the third plurality of magnetic pole pairs;
- and
- a cage rotor disposed between the outer cylinder and inner rotor, and separated from the outer cylinder and inner rotor by air gaps,
- wherein a magnetic flux density in the air gaps is substantially confined by the first and second plurality of ferromagnetic pole pieces.
A system configured to convert rotational energy between an outer cylinder, an inner rotor, and a cage rotor, the system comprising:
- an array of permanent magnets disposed on the outer cylinder and periodically separated by outer cylinder ferromagnetic pole pieces,
- an array of permanent magnets disposed on the inner rotor and periodically separated by inner rotor ferromagnetic pole pieces, and
- a cage rotor disposed between the outer cylinder and inner rotor, the cage rotor being separated from each of the outer cylinder and the inner rotor by first and second air gaps, respectively,
- wherein the outer cylinder ferromagnetic pole pieces and the inner rotor ferromagnetic pole pieces are configured to concentrate magnetic flux densities within the first and second air gaps.
Dependencies are inferred from the claim text.