Magnet structure

摘要

A magnet structure including a magnet and an integral magnetically permeable concentrator and methods for making the same are provided. In one embodiment, the concentrator has a substantially planar base and a post extending normal to the base and the magnetic element is a ring magnet having a central aperture through which the concentrator post extends. The concentrator is comprised of a plastic loaded with one or more magnetically permeable materials to a percentage suitable for providing desired magnetic field characteristics. The magnetic element may be comprised of a conventional magnetic material or a plastic loaded with one or more magnetic materials. An insert molding technique is described in which either the concentrator or magnetic element is prefabricated and inserted into a mold which is subsequently filled with a loaded plastic to provide the other component of the magnet structure. In an alternate fabrication technique, both the concentrator and magnet are sequentially formed by injection molding in the same mold. Also described is a magnet structure including a ring magnet having a central aperture in which a steel rod is disposed.