Abstract:
Methods and apparatus that employ a coil-less magnetoelectric flux switch arrangement to repeatedly switch magnetic flux from at least one permanent magnet for the purposes of generating motive force and/or electrical energy.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to magnetic fields from permanent magnets and the control of such magnetic fields for use in motors, generators and the like. More particularly, the present invention relates to methods and apparatus that employ a coil-less magnetoelectric (ME) magnetic flux switching construct to repeatedly switch magnetic flux from at least one permanent magnet for the purposes of generating motive force and/or electrical energy. 
   BACKGROUND OF THE INVENTION 
   The basic electromechanical processes involved in motors and generators are well-known. Mechanical power is produced (in the case of a motor) or electrical energy is generated (in the case of a generator) by the interaction of the electromagnetic forces between the rotor and stator. While almost all conventional motors utilize electromagnetic forces produced by running current through a series of windings in the form of coils of wire to generate the electromagnetic field that turns the rotor, the design of motors powered by magnetic fields from permanent magnets date back to as early as the 1840&#39;s. For numerous reasons, such permanent magnet powered motors have not been practical or competitive when compared to conventional electrical motors powered by electromagnetic fields. For general background information on permanent magnets and permanent magnet motor design, reference is made to Moskowitz, Permanent Magnet Design and Application Handbook (1976), Hanselman, Brushless Permanent Magnet Motor Design (2003), and Gieras et al., Permanent Magnet Motor Technology Revised (2003). 
   Recently a permanent magnet powered motor construct has been proposed that overcomes many of the challenges long associated with permanent magnet motors. U.S. Pat. Nos. 6,246,561 and 6,342,746 issued to Flynn describe methods for controlling the path of magnetic flux from a permanent magnet and devices incorporating the same. In these patents, a permanent magnet device includes a permanent magnet having north and south pole faces with a first pole piece positioned adjacent one pole face thereof and a second pole piece positioned adjacent the other pole face thereof so as to create at least two potential magnetic flux paths. A first control coil is positioned along one flux path and a second control coil is positioned along the other flux path, each coil being connected to a control circuit for controlling the energization thereof. The control coils may be energized in a variety of ways to achieved desirable motive and static devices, including linear reciprocating devices, linear motion devices, rotary motion devices and power conversion. 
   It has long been known that certain materials commonly referred to as liquid crystals can be oriented by a magnetic field. As early as 1894, Curie stated that it would be possible for an asymmetric molecular body to polarize in one direction under the influence of a magnetic field. The practical application of this effect is most commonly seen in magnetically ordered crystals even in conditions of symmetry of the molecules of the crystal. U.S. Pat. No. 4,806,858, for example, describes an inspection technique for magnetization that utilizes liquid crystal material to determine whether a sample has been appropriately magnetized. The use of a liquid crystal layer to change the magnetic flux resistance of a single magnetic path was described in Japanese Abstract No. 62117757A2 (1985). 
   More recently, the magnetoelectric effects of liquid crystal materials in the form of magnetorestrictive and piezoelectric materials have been the subject of renewed research and development. Generally referred to as magnetoelectric (ME) materials, the research and development into various properties of these ME materials are described, for example, in Ryu et al, “Magnetoelectric Effect in Composites of Magnetorestrictive and Piezoelectric Materials,” Journal of Electroceramics, Vol. 8, 107–119 (2002), Filipov et al, “Magnetoelectric Effects at Piezoresonance in Ferromagentic-Ferroelectric Layered Composites,” Abstract, American Physical Society Meeting (March 2003) and Chang et al., “Magneto-band of Stacked Nanographite Ribbons,” Abstract, American Physical Society Meeting (March 2003). 
   While many of the properties of ME materials are understood and there are numerous applications for the use of such liquid crystal materials, there is nothing which suggests how to make effective use of ME materials in the context of the design of permanent magnet motors and the like. 
   SUMMARY OF THE INVENTION 
   The present invention employs a coil-less magnetoelectric (ME) magnetic flux switching construct to repeatedly switch magnetic flux from at least one permanent magnet for the purposes of generating motive force and/or electrical energy. In one embodiment, a pair of permanent magnets are similarly oriented with each pole operably adjacent an associated first and second magnetic flux conductor. A first pair of coil-less ME magnetic flux switches are positioned between a corresponding first end of the first and second magnetic flux conductors and a third magnetic flux conductor. A second pair of coil-less ME magnetic flux switches are positioned between a corresponding second end of the first and second magnetic flux conductors and a fourth magnetic flux conductor. The first and second pairs of coil-less ME magnetic flux switches are repeatedly, alternately enabled to permit magnetic flux from the permanent magnets to cyclically flow through the third magnetic flux conductor and then the fourth magnetic flux conductor. Preferably, the coil-less ME magnetic flux switches are comprised of a laminate magnetoelectric (ME) material controlled by applying a voltage across the material to switch the magnetic conductivity of the ME material. 
   In one rotary motor embodiment of the present invention, the third and fourth magnetic flux conductors are different regions of a single rotor. The first and second magnetic flux conductors along with the permanent magnets serve as the stator. By continuous switching of the magnetic flux using the pair of coil-less ME magnetic flux switches, rotational motive force is applied to the rotor and a rotary motor is created. 
   In another rotary motor embodiment of the present invention, the rotor is provided with the permanent magnets and the coil-less ME magnetic flux switches and the stator is the common element that provides the different regions for the third and fourth magnetic flux conductors. In one version of this embodiment, the rotor may be the rotating element of the motor. In another version of this embodiment, the stator may be the rotating element of the motor. 
   In one rotary motor/generator embodiment of the present invention, one or more pickup coils are wound around at least one of the magnetic flux conductors of the stator element of a rotary motor. Unlike the motor construct of U.S. Pat. Nos. 6,246,561 and 6,342,746, current is not applied to any of these coils. Instead, the coils are used as the pickup coils of an alternating current generator. In an alternate embodiment of this invention, a current may be applied to the coils to utilizes these coils as control coils to enhance or supplement the magnetic flux switching effected by the coil-less ME magnetic flux switches as described by the present invention, or to provide additional operational benefits to the magnetic flux switching constructs as described in this invention and/or U.S. Pat. Nos. 6,246,561 and 6,342,746. 
   In one solid state generator embodiment of the present invention, a pickup coil is wound around at least one of the first and second magnetic flux conductors of a given solid state flux switching construct. In one version of this solid state generator embodiment, at least one of the first and second magnetic flux conductors having a pickup coils is shared by two or more solid state flux switching constructs. In another version of this solid state generator embodiment, a pickup coil is wound around at one of the third and fourth magnetic flux conductors of a given solid state flux switching construct and at least one of the third and fourth magnetic flux conductors are shared by two or more solid state flux switching constructs. 
   In another embodiment of a solid state generator in accordance with the present invention, a permanent magnet is at least partially coaxially surrounded by at least one coil-less ME magnetic flux switch with at least one coil positioned outside the coil-less magnetic flux switch. In a first version of this embodiment, the coil is wrapped coaxially with the permanent magnet and the coil-less magnetic flux switch. In a second version of this embodiment, the coil is positioned transverse to a longitudinal axis of the permanent magnet. In a third version of this embodiment, the coil is wrapped as one or more torroids positioned around the permanent magnet. 
   In another embodiment, at least one permanent magnet has each pole operably adjacent an associated first and second magnetic flux conductor. The first and second magnetic flux conductors each include a pair of selectively enabled permanent magnets with opposite pole orientations. Each permanent magnet in the first and second magnetic flux conductor is selectively enabled in this embodiment by a corresponding pair of coil-less magnetic flux switches interposed between the poles of each of these magnets and the corresponding adjacent portions of the first and second magnetic flux conductors. In one version of this embodiment, the pair of magnets in the first and second magnetic flux conductors can be separated with a magnetic insulator material such as MU metal. In another embodiment, a third and fourth magnetic flux conductor can be added to the corresponding end of the first and second magnetic flux conductors with an additional set of interposed coil-less magnetic flux switches arranged as described in the preferred embodiment. 
   In a linear motor/actuator embodiment in accordance with the present invention, the third and fourth magnetic flux conductors are effectively rails along which a shuttle is moved between carrying the permanent magnets, the first and second magnetic flux conductors and the coil-less ME magnetic switches. 
   In a preferred embodiment, the coil-less ME magnetic flux switches are implemented as a liquid crystal ME material that is electronically controllable. In an alternate embodiment, the ME material may be physically or optically controllable. Preferably, the ME material is processed onto a desired surface of the magnetic flux conductor or permanent magnet by thin film deposition, sputtering, or other thin film processing techniques. Alternatively, the ME material may be positioned physically interposed between the desired surfaces of the magnetic flux conductors or permanent magnets. In one embodiment, an index matching coating material may be interposed between the ME material and the desired surface of the magnetic flux conductors or permanent magnets to improve the magnetic flux characteristics of the completed construct. In another embodiment, a magnetic insulator material, such as MU metal can be used to house an entire magnetic flux switching construct to prevent external magnetic fields or may be used to magnetically isolate selected portions of a magnetic flux switching construct. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1 and 2  are schematic diagrams of a preferred embodiment of magnetic flux switching construct in accordance with the present invention. 
       FIG. 3  is a schematic diagram of one embodiment of a motor/generator in accordance with the present invention. 
       FIG. 4  is a schematic diagram of an alternate embodiment of a rotary motor in accordance with the present invention. 
       FIG. 5  is a schematic diagram of an alternative embodiment of a magnetic flux switching construct in accordance with the present invention. 
       FIGS. 6 and 7  are schematic diagrams of alternate embodiments of a motor/generator in accordance with the present invention. 
       FIGS. 8 ,  9  and  10  are schematic diagrams of alternative embodiments of a magnetic flux switching construct in accordance with the present invention. 
       FIG. 11  is a top plan view of a coaxial construction of a generator in accordance with the present invention. 
       FIG. 12  is a side view of the embodiment shown in  FIG. 11 . 
       FIG. 13  is a side view of an alternate embodiment of a coaxial construction of a generator in accordance with the present invention. 
       FIG. 14  is a side view of an embodiment of a coaxial construction of a generator in accordance with the present invention. 
       FIGS. 15 and 16  are schematic views of alternate embodiments of multiple flux switching constructs in accordance with one embodiment of the present invention. 
       FIG. 17  is a schematic diagram of an alternate embodiment of a linear motor/actuator in accordance with the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1 and 2 , a first embodiment of the of a magnetic flux switching construct  100  in accordance with the present invention will be described. A pair of permanent magnets  102 ,  104  are similarly oriented with each north pole (N) operably adjacent a first magnetic flux conductor  112  and each south pole (S) operably adjacent a second magnetic flux conductor  114 . Preferably, the permanent magnets  102 ,  104  are high strength ceramic or rare-earth permanent magnets such as neodidium, although any material capable of being magnetized and retaining that magnetization for a period of time sufficient for the intended use of the construct  100  could be used. Preferably, the magnetic flux conductors  112 ,  114  are low loss magnetic flux laminate materials, such as hyperco or an MD grade metal, although any iron, steel or ferrous alloy could be used provided that the magnetic flux loss of such material is within the design parameters of the strength of magnetic flux to be switched by the construct  100 . 
   A first pair of coil-less magnetoelectric (ME) magnetic flux switches  142 ,  144  are sandwiched between a corresponding first end of the first and second magnetic flux conductors  112 ,  114  and a third magnetic flux conductor  122 . A second pair of coil-less ME magnetic flux switches  152 ,  154  are positioned between a corresponding second end of the first and second magnetic flux conductors  112 ,  114  and a fourth magnetic flux conductor  124 . Preferably, each of the first and second pairs of coil-less ME magnetic flux switches  142 ,  144 ,  152 ,  154  are repeatedly, alternately enabled by an electronic control circuit  150  (shown for convenience as connected to just one switch). Preferably, the coil-less ME magnetic flux switches  142 ,  144 ,  152 ,  154  are comprised of a laminate magnetoelectric (ME) material such as the ME materials described in Ryu et al, “Magnetoelectric Effect in Composites of Magnetorestrictive and Piezoelectric Materials,” Journal of Electroceramics, Vol. 8, 107–119 (2002). Alternatively, the ME materials may be any ME or liquid crystal material. 
   As shown in  FIG. 1 , the switching of the first pair of coil-less ME magnetic flux switches  142  and  144  into an “on” position and the second pair of coil-less ME magnetic flux switches  152  and  154  into the “off” position permits magnetic flux as shown at  132 ,  134  from the permanent magnets  102 ,  104  to flow through the third magnetic flux conductor  122  and not the fourth magnetic flux conductor  124 . Switching of the first pair of coil-less ME magnetic flux switches  142  and  144  into an “off” position and the second pair of coil-less ME magnetic flux switches  152  and  154  into the “on” position then permits magnetic flux as shown at  136 ,  138  from the permanent magnets  102 ,  104  to flow through the fourth magnetic flux conductor  124  and not the third magnetic conductor  122 . 
   As this switching process is cyclically repeated under control of control circuit  150 , the switching of the magnetic flux between the positions at  132 ,  134  and the positions at  136 ,  138  is accomplished. As will be described, there are numerous applications for this switching construct  100 . In the case of the embodiment shown in  FIGS. 1 and 2 , a pair of pickup coils  162 ,  164  are wound around the first and second magnetic flux conductors  112 ,  114 , respectively. Electricity is generated at these pickup coils by virtue of the switching magnetic flux. It will be seen that an AC output signal is generated at the terminals of the pickup coils with a frequency that is dependent upon the speed at which the switching process is cycled. The frequency is limited by the switching speeds of the specifications of the particular coil-less ME magnetic flux switches utilized. In a preferred embodiment of a laminate coil-less ME magnetic flux switch, switching frequencies may be up to 100 GHz. It will be apparent that numerous rectification, power conditioning and other signal processing techniques can be used to modify the output of the pickup coils  162 ,  164 . In one embodiment, at least a portion of the output of the pickup coils  162 ,  164  is used to power the control circuit  150 . 
   Referring now to  FIG. 3 , the use of the magnetic flux switching construct of the present invention in a rotary motor application will be described. In general, the arrangement of components in this embodiment is similar to the rotary motors as described in U.S. Pat. Nos. 6,246,561 and 6,342,746, except that no control coils are used to control switching of the magnetic flux. The rotary motor  200  includes components that are similar to those used in the magnetic flux switching construct  100  except that the third magnetic flux conductor  122  and fourth magnetic flux conductor  124  are different regions of a single rotor element  202 . Preferably, the rotor element  202  includes a number of notches  210  that are dimensioned to permit the selectively coupling of the magnetic flux through the enabled pair of switches  142 ,  144  or  152 ,  154  in a timed manner to generate an effective rotating force in one rotational direction. The first and second magnetic flux conductors  112 ,  114  are curved and along with the permanent magnets  102 ,  104  serve as the stator  204  of the rotary motor  200 . By continuous switching of the magnetic flux using the pair of coil-less ME magnetic flux switches  142 ,  144  and  152 ,  154 , rotational motive force is applied to the rotor  202 . It will be seen that a rotary motor  200  having any even number of poles could be constructed, such as a six pole motor or a twelve pole motor, for example. For a detailed understanding of the timing and construction of a control circuit that would enable the switches  142 ,  144 ,  152 ,  154 , reference is made to U.S. Pat. Nos. 6,246,561 and 6,342,746. 
   In another embodiment of a rotary motor  220  as shown in  FIG. 4 , the rotor  222  is provided with the permanent magnets and the coil-less ME magnetic flux switches  142 ,  144 ,  152 ,  154  and the stator  224  is the common element that provides the different regions for the third and fourth magnetic flux conductors  122 ,  124 . In one version of this embodiment, the rotor  222  may be the rotating element of the motor  220 . In another version of this embodiment, the stator  224  may be the rotating element of the motor  220 . In one embodiment, the control circuit  150  can be carried by the rotor  222  and may be powered by a battery or by a shaft feed powered by pickup coils or an outside source. 
   In one rotary motor/generator embodiment as shown in  FIG. 3 , one or more pickup coils  162 ,  164  are wound around at least one of the first and second magnetic flux conductors  112 ,  114  of the stator  204  of rotary motor  200 . 
   In another embodiment as shown in  FIGS. 5–7 , at least one permanent magnet has each pole operably adjacent an associated first and second magnetic flux conductor. In one embodiment, the first and second magnetic flux conductors each include a pair of selectively enabled permanent magnets with opposite pole orientations. Each permanent magnet in the first and second magnetic flux conductor is selectively enabled in this embodiment by a corresponding pair of coil-less magnetic flux switches interposed between the poles of each of these magnets and the corresponding adjacent portions of the first and second magnetic flux conductors. In one version of this embodiment, the pair of magnets in the first and second magnetic flux conductors can be separated with a magnetic insulator material such as MU metal. In another embodiment, a third and fourth magnetic flux conductor can be added to the corresponding end of the first and second magnetic flux conductors with an additional set of interposed coil-less magnetic flux switches arranged as described in the preferred embodiment. This construct can be used to create a rotary motor/generator as shown in  FIGS. 6–7 , with any number of pickup coils. 
   In another embodiment as shown in  FIG. 8 , a single permanent magnet is used to provide magnetic flux for the magnetic flux switching construct and multiple pick up coils are arranged on each of the first and second magnetic flux conductors. 
   In another embodiment as shown in  FIG. 9 , a pair of permanent magnets are used to selectively provide magnetic flux with a second set of coil-less ME magnetic flux switches interposed in between the poles of each of the permanent magnets and the first and second magnetic flux conductors. This second set of coil-less ME magnetic flux switches may be controlled by the control circuit for the first set of coil-less ME magnetic flux switches that selectively flux connect the third and fourth magnetic flux conductors or may be controlled by a separate control circuit.  FIG. 10  is an alternate embodiment of the embodiment shown in  FIG. 9  with a pair of paired and coil-less ME magnetic flux switched set of permanent magnets used to generate magnetic flux for the present invention. 
   In another embodiment of a solid state generator as shown in  FIGS. 11–14 , a permanent magnet is at least partially coaxially surrounded by at least one coil-less ME magnetic flux switch with at least one coil positioned outside the coil-less magnetic flux switch. In a first version of this embodiment as shown in  FIGS. 11 and 12 , the coil is wrapped coaxially with the permanent magnet and the coil-less magnetic flux switch. In a second version of this embodiment as shown in  FIG. 13 , the coil is positioned transverse to a longitudinal axis of the permanent magnet. In a third version of this embodiment as shown in  FIG. 14 , the coil is wrapped as one or more torroids positioned around the permanent magnet. 
   In a solid state generator embodiment of the present invention as shown in  FIG. 15 , a pickup coil is wound around at least one of the first and second magnetic flux conductors of a given solid state flux switching construct. In this embodiment, at least one of the first and second magnetic flux conductors having a pickup coil is shared by two or more solid state flux switching constructs. In another version of this solid state generator embodiment as shown in  FIG. 16 , a pickup coil is wound around at one of the third and fourth magnetic flux conductors of a given solid state flux switching construct and at least one of the third and fourth magnetic flux conductors are shared by two or more solid state flux switching constructs. 
   In a linear motor/actuator embodiment in accordance with the present invention as shown in  FIG. 17 , the third and fourth magnetic flux conductors are effectively rails along which a shuttle is moved between carrying the permanent magnets, the first and second magnetic flux conductors and the coil-less ME magnetic switches. The rails may be tied together as part of a common superstructure. One or more sets of the magnetic flux switching construct may be incorporated into the shuttle portion of this embodiment. 
   It will be apparent that numerous combinations of the various embodiments of the present invention may be arranged in different combinations to take advantage of different aspects of the present invention. 
   The complete disclosures of the patents, patent applications and publications cited herein are incorporated by reference in their entirety as if each were individual incorporated. Various modifications and alterations to this invention will become apparent to those skilled in the art without departing from the scope or spirit of this invention.