Devices and methods for magnetic flux return optimization in electromagnetic machines
A rotor element configured for movement relative to a stator includes a backing member formed, at least in part, from a ferromagnetic material; a first magnetic pole having a first polarity; and a second magnetic pole having a second polarity, opposite the first polarity. The first magnetic pole and the second magnetic pole are coupled to a first surface of the backing member such that the second magnetic pole is disposed, relative to the first magnetic pole, at a distance defined in a direction of a width of the backing member. A thickness of the backing member is varied along the width of the backing member to form a plurality of alternating first portions and second portions. The first portions include protrusions extending from a second surface of the backing member, opposite the first surface, such that the first portions are thicker than the second portions.
1. An apparatus comprising:
a rotor element configured to be disposed for movement relative to a stator, the rotor element including:
a backing member formed at least in part of a ferromagnetic material and having a first surface and a second surface on an axially opposite side of the backing member than the first surface,
a first magnetic pole having a first polarity coupled to the backing member on the first surface, and
a second magnetic pole having a second polarity opposite the first polarity and coupled to the backing member on the first surface,
the backing member having a length, a width and a thickness defined between the first surface and the second surface of the backing member, the second magnetic pole being disposed relative to the first magnetic pole at a distance defined in a direction of the width of the backing member,
the thickness of the backing member varying along the width of the backing member such that the backing member includes a plurality of alternating first portions and second portions, the first portions including protrusions extending from the second surface and being thicker than the second portions.
2. The apparatus of claim 1 , wherein one of the first portions from the plurality of alternating first portions and second portions being disposed between the first magnetic pole and the second magnetic pole.
3. The apparatus of claim 1 , wherein the plurality of alternating first portions and second portions each extend along the length of the backing member.
4. The apparatus of claim 1 , wherein the length of the backing member varies along the width of the backing member.
5. The apparatus of claim 1 , wherein the length of the backing member varies along the width of the backing member such that the backing member has a first length at a first location between the first magnetic pole and the second magnetic pole that is greater than a second length in a second location.
6. The apparatus of claim 1 , further comprising:
a third magnetic pole coupled to the backing member and disposed relative to the second magnetic pole at a distance defined in a direction of the width of the backing member and on an opposite side of the second magnetic pole from the first magnetic pole, the third magnetic pole having the first polarity,
wherein one of the first portions from the plurality of alternating first portions and second portions being disposed between the second magnetic pole and the third magnetic pole.
7. The apparatus of claim 1 , wherein the rotor element is disposed for rotational movement relative to the stator, the axis of rotation of the rotational movement being approximately parallel to the thickness.
8. An apparatus, comprising:
a rotor element configured to be disposed for movement relative to a stator, the rotor element including:
a backing member formed at least in part of a ferromagnetic material and having a first surface and a second surface opposite the first surface,
a first magnetic pole having a first polarity coupled to the backing member on the first surface, and
a second magnetic pole having a second polarity opposite the first polarity coupled to the backing member on the first surface,
the backing member having a length, a width and a thickness, the second magnetic pole being disposed relative to the first magnetic pole at a distance defined in a direction of the width of the backing member,
the thickness of the backing member varying along the width of the backing member such that the backing member includes a plurality of alternating first portions and second portions, the first portions including protrusions extending from the second surface and being thicker than the second portions,
the rotor element being disposed for linear movement relative to the stator, the direction of the linear movement being approximately parallel to a direction of the width.
9. An apparatus comprising:
a rotor element configured to be disposed for movement relative to a stator, the rotor element including:
a backing member formed at least in part of a ferromagnetic material, the backing member having a first surface and a second surface opposite the first surface,
a first magnetic pole having a first polarity coupled to the backing member, and
a second magnetic pole having a second polarity opposite the first polarity and coupled to the backing member,
the backing member having a length defined radially from an innermost edge of the backing member to an outermost edge of the backing member, a width defined in a circumferential direction around the backing member and a thickness defined between the first surface and the second surface of the backing member, the second magnetic pole being disposed relative to the first magnetic pole at a distance defined in a direction of the width of the backing member, the length of the backing member varying along the width of the backing member.
10. The apparatus of claim 9 , wherein the thickness of the backing member varies along the width of the backing member such that the backing member includes a plurality of alternating first portions and second portions, the first portions being thicker than the second portions, one of the first portions being disposed between the first magnetic pole and the second magnetic pole.
11. The apparatus of claim 9 , wherein the thickness of the backing member varies along the width of the backing member such that the backing member includes a plurality of alternating first portions and second portions, the first portions being thicker than the second portions, the first portions and the second portions each extending along the length of the backing member.
12. The apparatus of claim 9 , wherein the length of the backing member varies along the width of the backing member such that the backing member has a first length at a first location between the first magnetic pole and the second magnetic pole that is greater than a second length in a second location.
13. The apparatus of claim 9 , further comprising:
a third magnetic pole coupled to the backing member and disposed relative to the second magnetic pole at a distance defined in a direction of the width of the backing member and on an opposite side of the second magnetic pole than the first magnetic pole, the third magnetic pole having the first polarity,
wherein the length of the backing member varies along the width of the backing member such that the backing member has a first length between the first magnetic pole and the second magnetic pole in the direction of the width that is greater than a second length between the second magnetic pole and the third magnetic pole in the direction of the width.
14. The apparatus of claim 9 , wherein the rotor element is disposed for rotational movement relative to the stator, the axis of rotation of the rotational movement being approximately parallel to the thickness.
15. An apparatus, comprising:
a rotor element configured to be disposed for movement relative to a stator, the rotor element including:
a backing member formed at least in part of a ferromagnetic material,
a first magnetic pole having a first polarity coupled to the backing member, and
a second magnetic pole having a second polarity opposite the first polarity and coupled to the backing member,
the backing member having a length, a width and a thickness, the second magnetic pole being disposed relative to the first magnetic pole at a distance defined in the direction of the width of the backing member, the length of the backing member varying along the width of the backing member,
the rotor element being disposed for linear movement relative to the stator, the direction of the linear movement being approximately parallel to a direction of the width.