Multi-winding homopolar electric machine
A multi-winding homopolar electric machine and method for converting between mechanical energy and electrical energy. The electric machine includes a shaft defining an axis of rotation, first and second magnets, a shielding portion, and a conductor. First and second magnets are coaxial with the shaft and include a charged pole surface and an oppositely charged pole surface, the charged pole surfaces facing one another to form a repulsive field therebetween. The shield portion extends between the magnets to confine at least a portion of the repulsive field to between the first and second magnets. The conductor extends between first and second end contacts and is toroidally coiled about the first and second magnets and the shield portion to develop a voltage across the first and second end contacts in response to rotation of the electric machine about the axis of rotation.
1. A method of generating an electrical voltage across two contacts comprising the steps of:
a) providing an electrical apparatus including,
a shaft defining an axis of rotation extending axially through a length of said shaft;
first and second magnets, each of said magnets being rotatable in unison with said shaft and including a charged pole surface and an oppositely charged pole surface, wherein charged pole surfaces face one another to form a repulsion field therebetween,
magnetic shielding extending between said magnets to confine at least a portion of the repulsion field to between said first and second magnets,
a conductor including first and second end contacts, said conductor being coiled about said first and second magnets and said magnetic shielding and extending across said oppositely charged pole; and
b) rotating said apparatus provided in step a) about the axis of rotation to develop a voltage across the first and second end contacts of the conductor.
2. The method according to claim 1 wherein the magnetic shielding includes an outer cylindrical shielding layer extending between respective outer radial end portions of the first and second magnets, and an inner cylindrical shielding layer extending between respective inner radial end portions of the first and second magnets.
3. The method according to claim 1 wherein the pole surfaces are perpendicular to the axis of rotation.
4. The method according to claim 1 wherein the pole surfaces are parallel to the axis of rotation.
5. The method according to claim 1 wherein the conductor extends in a helical winding about a toroidally-shaped core formed from the first and second magnets and the magnetic shield.
6. The method according to claim 1 wherein the shield circumferentiates the region between the first and second magnets.
7. The method according to claim 1 wherein the first magnet is concentric with the second magnet and defines an inner radius greater than an outer radius of the second magnet.