University of Virginia Patent Foundation

Other

Doris Wilsdorf

Charles M Adkins

Heinz G Wilsdorf

MP-A and MP-T machines are members of the Multipolar (MP) family of electric motors/generators and have similarly low weight and high power densities. Their current tubes comprise conductive 'S-ribbons' in electrically non-conductive material. S-ribbons are shaped so as in operation to periodically substantially overlap a multiplicity of neighboring zones of high magnetic B-field, alternating with gaps with low B in which B changes sign. Accordingly, MP-A and MP-T machines, respectively, generate AC and 3-phase current in the generator mode, and as motor are driven by AC or 3-phase at the appropriate frequency. Two modifications are introduced: (i) Machines with stationary magnet tubes/rotating current tube and (ii) machines with stationary current tube/rotating magnet tubes. The latter do not require electrical brushes and are eminently suited for simultaneous multiple uses. Also, these may operate while immersed in hostile fluids, including sea water.

MP-A and MP-T machines, multipolar machines for alternating and three-phase currents

A multifiber electrical brush formed of an electrically conductive matrix material having plural electrically conducting fiber wires embedded therein and extending therefrom, wherein the fiber wires have a diameter varying from 1 to 120.mu.m, a length on the order of 100 times greater than the diameter thereof, and a packing density between 1-25%. Suitable materials for the fiber wires are platinum, gold, silver, copper, palladium, or niobium which may be embedded in a copper, silver, or other suitable matrix material, or copper embedded in an aluminum matrix. The fiber wires may be provided with a coating of a suitable barrier material on the lateral surfaces thereof as may be required to protect the fiber wires from etching during removal of the matrix material, or to prevent and/or retard interdiffusion between the matrix material and the fiber wire material during annealing or hot-forming of brush stock, and/or to impart improved electrical performance to the resultant electrical brush. The electrical brush is fabricated typically by drawing, cutting, bundling and redrawing metal fiber wires, with or without a coating or casing of a barrier material, packed in a tube of matrix material, whereupon after shaping of the multi-filamentary ends to the shape of an object to which the brush is to make contact, the matrix is etched away to a predetermined length, preferably under high centrifugal forces in a centrifuge and/or with the application of ultrasound.

Electric brush

A versatile electrical fiber brush comprising the following components: Firstly a brush body, which is not necessarily equiaxed, non-porous, rigid or all in one piece, made of a matrix material, not necessarily electrically conductive, embedded in which is at least one set of similarly formed fibers, in which there may be embedded other, thinner fibers, and in these fibers still thinner fibers. Secondly, at least one fibrous part which is formed by removing from a part of the brush body most or all of the matrix material plus, as the conditions may make it advisable, some fibrous material. Third, at least one working surface, this being the macroscopic surface of a brush where it makes contact with the object(s) to which electrical connection shall be made. Fourth at least one set of electrically conductive fiber wires which form at least part of the working surface as well as of the fibrous part. The mechanical resilience and compliance of the fibrous parts is controlled by a system of secondary and tertiary fibers, these being generated from the embedment of fibers in fibers in the body of the brush. The electrical properties of the brush are controlled by the fiber wires. By making extremely large numbers of fiber wires of very small diameters to contact the object at the working surface of a brush, quantum-mechanical tunneling is expected to become the predominant mechanism of current conduction, yielding extremely good brush performance, while at same time brush wear is forecast to be very low.

Growing community of inventors

Charlottesville, VA, United States of America

Doris Wilsdorf