Abstract:
An electricity generator using a six-segment rotating flux switch, a 2×2 switching sequence with four magnetic flux switch sites, and a unique magnetic circuit design, all of which together alternate the magnetic flux from a stationary permanent magnet through a stationary magnetic segment around which is wound a pickup coil thereby inducing electricity in the pickup coil. Both the vector direction and the scalar value of the magnetic flux are alternated within the stationary magnetic segment resulting in a high power output of AC electricity.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to electrical energy generation and, in particular, to methods and apparatus wherein magnetic flux is switched through a flux path to produce electricity. 
     BACKGROUND OF THE INVENTION 
     Magnetic flux may exist in “free-space,” in materials that have the magnetic characteristics of free-space, and in materials with magnetically conductive characteristics. The degree of magnetic conduction in magnetically conductive materials is typically indicated with a B-H hysteresis curve, by a magnetization curve, or both. 
     Permanent magnets may now be composed of materials that have a high coercively (Hc), a high magnetic flux density (Br), a high magneto motive force (mmf), a high maximum energy product (BHmax), with no significant deterioration of magnetic strength over time. An example is the N52 NdFeB permanent magnet from magnet supplier, www.magnet4sale.com, which has an Hc of 1,079,000 Amperes/meter, a Br of 1.427 Tesla, an mmf ranging up to 575,000 Ampere-turns, and a BHmax of 392,000 Joules/meter 3 . 
     According to Moskowitz, “Permanent Magnet Design and Application Handbook” 1995, page 52, magnetic flux may be thought of as flux lines which always leave and enter the surfaces of ferromagnetic materials at right angles, which never can make true right-angle turns, which travel only in straight or curved paths, which follow the shortest distance, and which follow the path of lowest reluctance (resistance to magneto motive force). 
     Free space presents a high reluctance path to magnetic flux. There are many materials that have the magnetic characteristics similar to those of free space. There are other materials that offer a low or lower reluctance path for magnetic flux, and it is these materials that typically comprise a defined and controllable magnetic path. 
     High-performance magnetic materials for use as magnetic paths within a magnetic circuit are now available and are well suited for the (rapid) switching of magnetic flux with a minimum of eddy currents. Certain of these materials are highly nonlinear and respond to a “small” applied magneto motive force (mmf) with a robust generation of magnetic flux (B) within the material. The magnetization curves of such materials show a high relative permeability (ur) until the “knee of the curve” is reached, at which point ur decreases rapidly approaching unity as magnetic saturation (Bs) is reached. 
     A “reluctance switch” is a device or means that can significantly increase or decrease the reluctance of a magnetic path. This is ideally done in a direct and rapid manner, while allowing a subsequent restoration to the previous reluctance, also in a direct and rapid manner. A reluctance switch typically has analog characteristics. By way of contrast, an off/on electric switch typically has a digital characteristic, as there is no electricity “bleed-through.” With the current state of the art, however, reluctance switches exhibit some magnetic flux bleed-through. Reluctance switches may be implemented mechanically, such as to cause keeper movement to create an air gap, or rotating a lower reluctance material through an air gap (a high reluctance path segment) or electrically by various other means. 
     One electrical reluctance switch implementation uses a control coil or coils wound around a magnetic path or a sub-member that affects the path. U.S. Navy publication, “Navy Electricity and Electronics Series, Module 8—Introduction to Amplifiers” September 1998, page 3-64 to 3-66 describes how to modulate alternating current by changing the reluctance of the entire primary magnetic path by these means, one of which is used in a saturable-core reactor and the other in a magnetic amplifier. Flynn, U.S. Pat. No. 6,246,561; Patrick et al., U.S. Pat. No. 6,362,718; Pedersen, U.S. Pat. No. 6,946,938; Marshall, and US Patent Application 2005/01256702-A1 all disclose methods and apparatus that employ this type of reluctance switch for switching magnetic flux from a stationary permanent magnet or magnets for the purpose of generating electricity (and/or motive force). 
     Another electrical means of implementing a reluctance switch is the placement within the primary magnetic path of certain classes of materials that change (typically increase) their reluctance upon the application of electricity. A different way of implementing a reluctance switch is to saturate a sub-region of a primary magnetic path by inserting conducting electrical wires into the material comprising the primary magnetic path. Such a technique is described by Konrad and Brudny in “An Improved Method for Virtual Air Gap Length Computation,” in IEEE Transactions on Magnetics, Vol. 41, No. 10, October 2005. A further electrical means of implementing a reluctance switch is described by Valeri Ivanov of Bulgaria on the website www.inkomp-delta.com. 
     SUMMARY OF THE INVENTION 
     An electricity generator using a six-segment rotating flux switch, a 2×2 switching sequence with four magnetic flux switch sites, and a unique magnetic circuit design, all of which together alternate the magnetic flux from a stationary permanent magnet through a stationary magnetic segment around which is wound a pickup coil thereby inducing electricity in the pickup coil. Both the vector direction and the scalar value of the magnetic flux are alternated resulting in a high power output of AC electricity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an oblique drawing of a preferred embodiment of the invention; 
         FIG. 2  is a detail drawing of the magnetic flux delivery subsystem including the rotating disk; 
         FIG. 3  is a detail drawing of the magnetic flux delivery subsystem without the disk; 
         FIG. 4  is a detail drawing of the electromagnetic induction subsystem; 
         FIGS. 5A-5G  illustrate how an alternating current is induced in a coil via rotation of the disk; and 
         FIG. 6  is a magnetic equivalent circuit of the preferred embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is an oblique drawing of a preferred embodiment of the invention depicted generally at  100 . The apparatus broadly comprises a magnetic flux delivery subsystem  102  and an electromagnetic induction subsystem  104  separated by a rotating disk  106 . As will be seen, in contrast to typical electrical generators, the system induces electricity in a stationary winding, wound around a magnetic path in which electricity is generated to a varying magnetic field, thereby generating electrical energy, without the use of rotating windings. 
       FIG. 2  is a detail drawing of the magnetic flux delivery subsystem including the rotating disk, and  FIG. 3  is a detail drawing of the magnetic flux delivery subsystem without the disk. 
     The magnetic flux delivery subsystem comprises a plate  103  to which there is coupled two C-shaped members  105 ,  114 . Each C-shaped member comprises two arms extending away from plate  103  and toward the rotating disk  106 . In particular, member  105  includes arms  107 ,  108 , and member  114  includes arms  116 ,  118 . Arm  107  terminates in a flat surface N 1 ; arm  108  terminates in flat surface N 2 ; arm  116  terminates in flat surface S 1 ; and arm  118  terminates in flat surface S 2 . All of the flat surfaces N 1 , N 2 , S 1 , S 2  lie in a common first plane. The ends of the arms  107 ,  108 ,  116 ,  118  are preferably chamfered as shown so that the surfaces N 1 , N 2 , S 1 , S 2  better conform to the magnetically conductive wedges of the rotating disk described below. 
     A magnet is interposed between the back surfaces of one or both of the C-shaped members and the plate  103 . As seen in  FIGS. 2, 3 , two permanent magnets  124 ,  126  are shown. If two magnets are used, they are arranged in ‘series,’ that is, with their poles alternating such that their magnetic fields are additive. Arbitrarily, surfaces N 1 , N 2  are ‘north’ poles, whereas surfaces S 1 , S 2  are ‘south’ poles. If the magnet(s) are reversed so, too, would these arbitrary poles. 
     The electromagnetic induction subsystem, illustrated in  FIG. 4 , also comprises a pair of C-shaped members  142 ,  152 . Each C-shaped member also has a pair of arms oriented toward rotating disk  106 . In particular, member  142  includes arms  144 ,  146 , and member  152  includes arms  154 ,  156 . Arm  144  terminates in a flat surface  1 ; arm  146  terminates in flat surface  2 ; arm  154  terminates in flat surface  3 ; and arm  156  terminates in flat surface  4 . All of the flat surfaces  1 ,  2 ,  3 ,  4  lie in a common second plane, spaced-apart from and parallel to the first plane. 
     Continuing the description of the electromagnetic induction subsystem, a bar  160  shown in  FIG. 1  is disposed between the mid-sections of C-shape members  142 ,  152 . A coil of wire  164 , wrapped around bar  160 , is interconnected to a utilization device  166 . As described in detail below, during operation, magnetic flux reverses direction through bar  160 , thereby inducing an alternating current through wire  164 . 
     The surfaces of the arms associated with the magnetic flux delivery subsystem are axially aligned with the surfaces of the arms associated with the electromagnetic induction subsystem. The first and second planes are spaced apart at a distance to receive rotating disk  106 . In the preferred embodiment, the surfaces are as close as possible to the front and back surfaces of the disk while allowing it to rotate freely. 
     Disk  106  is constructed from a non-magnetic material such as aluminum, but includes six flux-carrying inserts A, B, C, D, E, F best seen in  FIG. 2 . The wedge-shaped inserts, which extend all the way through the disk  106  from front to back surface, are constructed from a high magnetic permeability material such as iron or other ferromagnetic material. Disk  106  is supported on a rod  130  that rotates about a central axis. The ends of the rod include some form of bearing structure  132  engineered to minimize friction. Needle or gas bearing may be used, for example. 
     The C-shaped members of the magnetic flux delivery and electromagnetic induction subsystems, as well as bar  160 , are preferably constructed from laminated electrical steel material, most preferably HF-10 C5, with laminations having thicknesses in the range of 0.010 inches. Laminations are used to inhibit eddy currents and improve efficiency. In terms of dimensions, the apparatus may be constructed in different sizes. In one example, the various bars have cross sections with dimensions ranging from 0.5 to 1.5 inches. Disk  106  may have a diameter on the order of 14 inches, in which case the surfaces facing the disk are about 0.010 inches apart. 
     The disk may rotate in either direction, at different speeds, though constant speeds in the range of 1000 to 4000 RPM are preferred. Any mechanical energy may be used to turn the disk, including wind, water, manual cranking, and so forth. The disk may also be motor-driven, using at least a portion of the alternating current produced by the electromagnetic induction subsystem. 
       FIGS. 5A-5G  illustrate how an alternating current is induced in coil  164  via rotation of disk  106 .  FIG. 5A  illustrates an arbitrary starting position, with rotation arbitrarily proceeding in a counter-clockwise direction. In  FIG. 5A , flux from surface N 1  of the magnetic flux delivery subsystem (behind insert A), is able to conduct through insert A, into surface  1 , through bar  162 , through insert D, and into surface S 2  of the magnetic flux delivery subsystem (behind insert D). Arbitrarily, then, magnetic flux may be thought of as ‘flowing’ from right to left through bar  162  around which wire  164  is wound. A meter  500  in series with wire  164  shows a positive current in one direction (assuming continuous rotation and a previous flux reversal as described below). 
     In  FIG. 5B , the disk has rotated 5 degrees CCW. Inserts A, D are no longer as well aligned with the corresponding surfaces of the magnetic flux delivery and electromagnetic induction subsystems, causing the current induced in the coil to diminish somewhat, as indicated by meter  500 . In  FIG. 5C , at 10 degrees of rotation, the overlap and induced current continue to diminish. In  FIG. 5D , the overlap of insert A and surface N 1 , the overlap of insert B and S 1 ; the overlap of insert D and surface S 2 , and the overlap of insert E and surface N 2  are all equal, resulting in little if any induced current. 
     In  FIG. 5E , however, at 20 degrees of rotation, the overlap of inset B and surface S 1 , as well as the overlap of insert E and surface N 2  begin to increase, now causing a left-to-right flux to develop though bar  160 . This overlap continues to increase in  FIGS. 5F and 5G , maximizing the induced current from left-to-right in the drawing. As rotation continues, the process described above will repeat, involving the other inserts, such that the flux will reverse precisely three times through bar  160  for each full rotation of disk  106 .