Multi-pole magnetization of a magnet
AssigneeApple Inc.
InventorJean-Marc GERY
Life of this patent
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Abstract
A method of magnetizing a multi-pole magnet includes the steps of obtaining a magnetization coil having a magnetization zone and a central axis, and positioning a magnet within the magnetization zone. The method also includes positioning at least one pair of shield bodies including a conductive material proximate the first and second surfaces of the magnet, with the shield bodies being aligned together to cover both sides of at least a first region of magnet and expose both sides of at least a second region of the magnet. The method further includes energizing the magnetization coil to generate an applied magnetic field within the magnetization zone that is sufficient to induce eddy currents in the at least one pair of shield bodies and to magnetize the exposed second region of the magnet.
Claims20
A method for forming a multi-pole magnet using a magnetization coil having a magnetization zone and a central axis and configured to generate a magnetic field within the magnetization zone having flux lines that are substantially parallel to the central axis, the method comprising:
- using a shield body to magnetically shield a portion of a magnet located within the magnetization zone, the shield body being formed from a conductive material and with a thickness sufficient to allow for the inducement of eddy currents in accordance with the magnetic field;
- and
- using the magnetization coil to generate the magnetic field within the magnetization zone, the magnetic field having a field strength sufficient to magnetize an unshielded portion of the magnet and to induce eddy currents in the shield body that prevent magnetization of the shielded portion of the magnet.
A method for magnetizing a monolithic multi-pole magnet using a magnetization coil having a magnetization zone and a central axis and configured to generate a magnetic field within the magnetization zone having flux lines aligned substantially parallel with the central axis, the method comprising:
- positioning a magnet within the magnetization zone and transverse to the central axis, the magnet having a first surface and a second surface opposite the first surface;
- positioning at least one pair of shield bodies comprising a conductive material proximate the first and second surfaces of the magnet, the shield bodies cooperating to cover both sides of at least a first region of the magnet and to expose both sides of at least a second region of the magnet;
- and
- energizing the magnetization coil to generate a magnetic field within the magnetization zone sufficient to magnetize the second region of the magnet and to induce eddy currents in the shield bodies, the eddy currents shielding the first region from the magnetic field.
A system for magnetizing a multi-pole magnet, comprising:
- a magnetization coil that defines a magnetization zone having a central axis and configured to generate a magnetic field within the magnetization zone having flux lines that are substantially parallel to the central axis and having a size and shape in accordance with a magnet oriented transverse to the central axis, the magnet having a first surface and a second surface opposite the first surface;
- at least one shield body that is movable within the magnetization zone and comprising a conductive material with a thickness sufficient to allow for the inducement of eddy currents in the shield body and adapted for positioning proximate at least one surface of the magnet and covering a first portion of the at least one surface and exposing a second portion of the at least one surface;
- and
- an energy source configured to provide sufficient power to the magnetization coil to generates a magnetic field within the magnetization zone having a field strength sufficient to magnetize the magnet proximate the second portion of the at least one surface and to induce eddy currents in the shield body.
Dependencies are inferred from the claim text.