HK1078175B - Electrical machine, method of generating electricity and method of providing motive force - Google Patents

Description

Electric machine, method of generating electricity and method of providing motive power

Technical Field

Embodiments of the present invention relate to an electric machine that may be used as a motor or a generator. The motor uses high frequency commutation of magnetic flux to achieve high efficiency and high power density.

Background

Motors and alternators are designed for high efficiency, high power density and low cost. High power density is optionally achieved by operating the alternator at high rotational speeds, and thus high electrical frequencies. However, high electrical frequencies result in high magnetic core losses and low efficiency. It is desirable to provide a motor and alternator that has very low core losses, making it practical to operate at high electrical frequencies.

If high rotational speeds cannot be provided, prior art motors or alternators must have a large number of poles to provide high electrical frequencies at low rotational speeds. Because of space constraints, there is a practical limit to the number of poles that a prior art motor or alternator can have, so once this limit is reached, the motor or alternator must be relatively large and inherently have a low power density at low rotational speeds in order to reach a certain power level. It is desirable to provide an electric motor or alternator that can have many times the number of poles that can currently provide high power density, and that has good efficiency even at low rotational speeds.

Another problem with prior art motors and alternators is that they require permanent magnets or electromagnets to provide the magnetic field. Each type of magnet has some advantages and some disadvantages, so that a decision on the balance between the two types of magnets has to be made. Permanent magnets offer simplicity, they have the advantage that they do not require an electrical input, which allows for a brushless motor or alternator. The permanent magnets also make it possible to design an electric motor or alternator with a relatively high power density. However, they do not allow operation over a wide speed range and they cannot be de-energized if desired. The electromagnets can be de-energized, however, they occupy more space and require a slip ring to extract power, which is a parasitic power loss of the system. Therefore, to eliminate the need for a clutch, many electric machines must be configured as motors or alternators with low power density, low efficiency and high complexity. It is desirable to provide an electric motor and alternator that can combine the advantages of permanent magnets and electromagnets.

The design balance of existing motors and alternators has hindered the commercial success of some motors and alternators. For example, in-wheel motors that drive the wheels of vehicles have not been commercialized because low speed output requires large motors that are not compatible with the weight and size requirements of the vehicle suspension and drive system. A successful hub motor requires a power density many times higher than that provided by prior art motors and it must maintain good efficiency and have variable field strength. Such a motor would be of great help to make electric and hybrid electric vehicles commercially acceptable.

Disclosure of Invention

According to the present invention, there is provided a motor comprising: a magnet, an electrical conductor arranged as a ring, a plurality of magnetic flux conductors that direct magnetic flux from the magnet through the ring of electrical conductors, wherein a set of north pole magnetic flux conductors direct the magnetic flux through the ring in a radially outward direction and a set of south pole magnetic flux conductors direct the magnetic flux through the ring in a radially inward direction, and a switch for alternately connecting and disconnecting pairs of the sets of north and south pole magnetic flux conductors, wherein each pair comprises one north pole magnetic flux conductor and one south pole magnetic flux conductor.

According to the present invention, there is also provided a method of generating electricity, comprising: providing a magnet, providing an electrical conductor arranged as a ring, using a plurality of magnetic flux conductors to direct magnetic flux from the magnet through the ring of electrical conductors, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction, and alternately switching the magnetic flux conductors between an on state and an off state to induce an alternating current in the electrical conductor.

According to the present invention there is also provided a method of providing motive power comprising: providing a magnet, providing a first electrical conductor arranged as a ring, using a plurality of magnetic flux conductors to direct magnetic flux from the magnet through the ring of the first electrical conductor, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction, using a switch on a rotor to switch the magnetic flux conductors between an on state and an off state, and providing an alternating current in the first electrical conductor such that when the polarity of the alternating current changes sign, the switch moves between successive north and south pole sets of magnetic flux conductors.

According to the present invention, there is also provided a motor including: a magnetic flux source, an electrical conductor arranged as a loop, a plurality of magnetic flux conductors directing magnetic flux from the magnetic flux source through the loop of electrical conductor, wherein a set of north pole magnetic flux conductors directs the magnetic flux through the loop in a radially outward direction and a set of south pole magnetic flux conductors directs the magnetic flux through the loop in a radially inward direction, and a switch for alternately connecting and disconnecting a plurality of pairs of the sets of north and south pole magnetic flux conductors, wherein each pair comprises one north pole magnetic flux conductor and one south pole magnetic flux conductor.

According to the present invention, there is also provided a motor including: a magnet, a ring of electrically conductive material, a plurality of magnetic flux conductors that direct magnetic flux from the magnet through the ring of electrically conductive material, wherein a set of north pole magnetic flux conductors direct the magnetic flux through the ring in a radially outward direction and a set of south pole magnetic flux conductors direct the magnetic flux through the ring in a radially inward direction, and a switch for alternately connecting and disconnecting pairs of the sets of north and south pole magnetic flux conductors, wherein each pair comprises one north pole magnetic flux conductor and one south pole magnetic flux conductor.

According to the present invention, there is also provided a motor including: a magnet, an electrical conductor arranged as a loop, means for guiding a magnetic flux from said magnet through said loop of the electrical conductor, comprising first means for guiding said magnetic flux through said loop in a radially outward direction, and second means for guiding said magnetic flux through said loop in a radially inward direction, and a switch for alternately connecting and disconnecting pairs of said first and second means for guiding a magnetic flux, each of which comprises one said first means for guiding a magnetic flux and one said second means for guiding a magnetic flux.

According to the present invention, there is also provided a motor including: a magnet, an electrical conductor arranged as a ring, a plurality of magnetic flux conductors that direct magnetic flux from the magnet through the ring of electrical conductors, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction to form a first magnetic circuit and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction to form a second magnetic circuit, and a switch for alternately contacting pairs of the north and south pole sets of magnetic flux conductors to complete the first and second magnetic circuits, wherein one north pole magnetic flux conductor and one south pole magnetic flux conductor.

Embodiments of the present invention provide a motor/alternator that provides many times higher power density than prior art devices. This is accomplished primarily by greatly reducing the core losses, allowing the motor/alternator to operate at higher electrical frequencies. Since it operates at a high electrical frequency at a given rotational speed, the output voltage is higher than in prior art alternators if the device is operated as an alternator. This reduces the current through the windings and substantially reduces resistive losses in the device.

Conventional motors and alternators use varying currents in the windings to produce varying magnetic fields in the stator, rotor, or both. Instead, embodiments of the present invention vary the constant magnetic field by varying the magnetic flux path of the magnetic field. Hysteresis and eddy currents are the main sources of core losses. Hysteresis is caused by the reversal of magnetic polarity in the material and eddy currents are caused by changes in the magnetic field strength in the material, independent of the magnetic field reversal. Embodiments of the present invention achieve low core losses by preventing hysteresis in the volume of the core, and using an eddy current resistant material such as powdered iron for that portion of the core. Embodiments of the present invention further reduce core losses by using materials that experience low hysteresis losses in the small portion of the core that experiences magnetic field reversal.

A motor/alternator according to an embodiment of the present invention uses a single magnet having north and south poles. The magnet may alternatively be a permanent magnet or an electromagnet or a combination of both. A plurality of magnetic flux conductors directs the magnetic field of a single magnet. One half of the magnetic flux conductors are in contact with the north pole of the magnet so that they have a positive pole, and one half of the magnetic flux conductors are in contact with the south pole of the magnet so that they have a negative pole. The north and south magnetic flux conductors are separated from each other by an air gap sufficient to minimize magnetic flux leakage between the conductors. A plurality of switching devices are attached to the rotor. These switching devices are in contact between the magnetic flux conductors to alternately open and close a magnetic circuit for conducting magnetic flux between the north and south poles of the magnets of the device. These flux switches are the only parts of the device that experience hysteresis. The magnetic flux conductors are arranged such that they alternately conduct magnetic flux in opposite directions around the power coil. One half of the magnetic flux conductor produces a clockwise magnetic field around the power coil and the other half produces a counter-clockwise magnetic field around the coil. When the switching device opens and closes the ac magnetic circuit, the polarity of the magnetic field around the power coil is reversed. When used as an alternator, the reversal of the polarity of the magnetic field induces an alternating EMF voltage in the power coil. If an AC voltage is applied to the power coil, the device will act as a motor by moving the switching device on the rotor between the magnetic flux conductors.

The magnetic flux conductors can be small so many pairs can fit in a small space before they become too close and magnetic leakage occurs. Since each pair of magnetic flux conductors includes one pole in the motor/alternator, many times more poles are possible with embodiments of the present invention than with prior art motors and alternators. The large number of poles allows embodiments of the present invention to achieve the high electrical frequencies required for high power density while operating at moderate rotational speeds.

The device according to an embodiment of the invention has the advantage that it uses only a single magnet. This allows for a very simple and economical construction compared to many prior art motors and alternators. Embodiments of the present invention result in a motor or alternator having a large number of poles that does not require a large number of magnets. Furthermore, since the magnets are on the stator, there is no need for a slip ring to get the current to the electromagnets, greatly simplifying its implementation. Since the magnets are selectively permanent magnets or electromagnets, there is great flexibility in selecting the magnet that works best for the desired use. One possibility is that the magnets are a combination of hybrid permanent magnets, electromagnets. In such a configuration, the permanent magnet provides a magnetic field of fixed strength, and the additional electromagnet is used to increase the magnetic field to enhance the magnetic field or potentially decrease the magnetic field. By adjusting the strength of the magnetic field by the electromagnet, the overall field strength of the motor or alternator can be selectively adjusted as desired.

An alternate embodiment of the present invention provides a three-phase device. In its three-phase embodiment, only one magnet or a hybrid magnet is still required, which magnetizes the magnetic flux conductors around three separate coils arranged one above the other. The flux switches are arranged so that the magnetic circuit is completed around one coil at a time. The flux switches are spaced so that a three-phase output is produced when used as an alternator and so that the three-phase power drive is used when used as a motor.

Embodiments of the present invention have many possibilities in layout and geometry. The rotor may alternatively be located on the inside or outside of the stator, or even on the face. The magnetic flux switch and the magnetic flux conductor may alternatively take a variety of shapes, for example, depending on the intended use. The magnet may alternatively be a permanent magnet, an electromagnet, or both. Still further variations may not be described herein but are well within the scope of the present invention.

The motor/alternator according to embodiments of the present invention operates at a very high electrical frequency for a given rotational speed as compared to prior art devices. This results in a very high power density. In one embodiment, the operating electrical frequency is 10 times higher than in the prior art device for a given rotational speed. This results in a 10 times higher power density. High frequency operation also results in a reduced need for capacitors for smooth power output when the device is used as an alternator. High frequency operation also allows the device to operate at much higher voltages than prior art devices, thereby improving the battery charging capability of the device or simplifying its interface with the inverter. Higher voltages also result in smaller wires, lower currents and lower power losses in the device.

Additional features and advantages according to the invention in its various embodiments will be apparent from the remainder of the disclosure.

Drawings

Features and advantages of embodiments in accordance with the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:

figure 1 shows an exploded view of a stator assembly according to an embodiment of the present invention.

Fig. 2 shows an exploded view of a magnet assembly according to an embodiment of the invention.

FIG. 3 shows a magnetic flux conductor connected to the north pole of a magnet according to an embodiment of the present invention.

FIG. 4 shows a single north pole magnetic flux conducting lamination according to an embodiment of the present invention.

FIG. 5 illustrates a magnetic flux conductor connected to a south pole of a magnet in accordance with an embodiment of the present invention.

Fig. 6 illustrates a single south pole magnetic flux conducting lamination in accordance with an embodiment of the present invention.

Fig. 7 shows three magnetic flux conductors connected to the north pole of the magnet stack and three magnetic flux conductors connected to the south pole of the magnet stack according to an embodiment of the present invention.

Fig. 8 illustrates an exploded view of a rotor assembly according to an embodiment of the present invention.

Fig. 9 shows a partial cross section of a motor-alternator according to an embodiment of the invention.

Fig. 10 shows the magnetic flux in the magnetic flux conductors during the first orientation of the rotor according to an embodiment of the invention.

Fig. 11 shows the magnetic flux in the magnetic flux conductors during the second orientation of the rotor according to an embodiment of the invention.

FIG. 12 illustrates an assembled and packaged stator and an assembled and packaged rotor according to embodiments of the invention.

FIG. 13 shows a partial cross section of a motor-alternator according to an embodiment of the present invention.

Fig. 14 shows the magnetic flux in the magnetic flux conductors during the first orientation of the rotor according to an embodiment of the invention.

Fig. 15 shows the magnetic flux in the magnetic flux conductors during the second orientation of the rotor according to an embodiment of the invention.

Figure 16 illustrates an exploded view of a stator assembly according to an embodiment of the present invention.

FIG. 17 shows a magnetic flux conductor connected to the north pole of a magnet according to an embodiment of the present invention.

FIG. 18 shows a single north pole magnetic flux conducting lamination according to an embodiment of the present invention.

FIG. 19 illustrates a magnetic flux conductor connected to a south pole of a magnet in accordance with an embodiment of the present invention.

Fig. 20 shows a single south pole magnetic flux conducting lamination in accordance with an embodiment of the present invention.

Fig. 21 illustrates an exploded view of a rotor assembly according to an embodiment of the present invention.

Fig. 22 shows the magnetic flux in the magnetic flux conductors during the first orientation of the rotor according to an embodiment of the invention.

Fig. 23 shows the magnetic flux in the magnetic flux conductors during the second orientation of the rotor according to an embodiment of the invention.

Fig. 24 shows the magnetic flux in the magnetic flux conductors during a third orientation of the rotor according to an embodiment of the invention.

Fig. 25 shows the magnetic flux in the magnetic flux conductors during a fourth orientation of the rotor according to an embodiment of the invention.

Figure 26 illustrates an exploded view of a stator assembly according to an embodiment of the present invention.

Fig. 27 illustrates a rotor assembly according to an embodiment of the present invention.

Figure 28 shows a cross-sectional view of a magnetic flux conductor and a magnetic flux switch according to an embodiment of the present invention.

Fig. 29 shows a partial cross-section of a motor/alternator according to an embodiment of the present invention.

Detailed Description

The invention has been shown and described in a number of different embodiments, primarily four specifically described embodiments. The first particularly described embodiment is a single phase device. The second specifically described embodiment is also a single phase device with a different flux path geometry. The third describes a three-phase type device. The fourth is a one-way type device with its rotor inside the stator. There are other embodiments of the device beyond these specifically described (such as a three-phase device with a rotor inside) which, although not explicitly described herein, may suggest, or be fully understood from these four embodiments.

As shown in fig. 1, an embodiment of the invention includes a stator 1 having a ring magnet 2, a set of north magnetic flux conductors 4, a set of south magnetic flux conductors 6, and a power coil 8. North and south magnetic flux conductors 4 and 6 are in direct contact with the magnet 2. The magnetic flux conductors 4, 6 are made of a material that readily conducts magnetic fields. Ferrous materials may be suitable, and one particular material is powdered metal, although other materials may alternatively be used. The magnetic flux conductors 4 and 6 direct the magnetic field of the magnet 2 towards the power coil 8. The power coil 8 is an electrical coil in which a voltage is generated when the device is used as an alternator. When used as a motor, the power coil 8 provides voltage and current to power the device. The power coil 8 includes an electrical conductor 10 which collects the output power when the device is used as an alternator or provides power when the device is used as a motor.

Fig. 2 is a more detailed exploded view of the ring magnet of fig. 1. One embodiment of the present invention is a hybrid magnet comprising a concentrically disposed permanent magnet 12 and electromagnet 14, although embodiments of the present invention may alternatively comprise only a single permanent magnet 12 or a single electromagnet 14. In the configuration of the magnet 2 having only the permanent magnet 12, the electromagnet 14 is absent, and the electrical lead 16 connected to the electromagnet 14. In the structure of the magnet 2 having only the electromagnet 14, the permanent magnet 12 is replaced by a cylinder of ferromagnetic material having the same shape as the permanent magnet to conduct the magnetic flux generated by the electromagnet 14. The magnetic field is then increased or decreased by adjusting the voltage applied to the electrical leads 16 of the electromagnet 14. In one configuration of the magnet 2 in which both the permanent magnet 12 and the electromagnet 14 are used as a hybrid magnet, the electromagnet 14 may alternatively be added to the magnetic field of the permanent magnet 12 or subtracted from the magnetic field of the permanent magnet 12. This allows the field strength to be adjusted by the electromagnet 14 when starting, clutching or braking is required, while also allowing the motor/alternator to operate most of the time without an external current source using only the field generated by the permanent magnet 12.

The magnetic flux conductor 4 connected to the north pole of the magnet 2 may alternatively be formed as a single piece as shown in fig. 3. The magnetic flux conductor includes a mounting ring 18 that provides structural support for the magnetic flux conductor. The mounting ring 18 contacts the north pole side of the magnet 2 (not shown) and holds the magnet 2 in its proper position. Attached to mounting ring 18 is a plurality of flux conductor laminations 20. The laminations 20 direct the magnetic field from the magnet 2 to the appropriate location. Each lamination 20 extends radially outward from the mounting ring 18 and is separated into two conductive portions.

Fig. 4 shows a single north pole flux conductor lamination 20. The upper conductive portion 22 extends radially outward directly from the mounting ring 18. The lower conductive portion 24 extends downward from the upper conductive portion 22. Between the upper and lower conductive portions 22 and 24, there is a recess 26 defined in each lamination 20 to retain the power coil 8 (not shown). In addition to extending downward, each lower conductive portion 24 is bent such that the lower conductive portion 24 is not vertically aligned with the upper conductive portion 22. Each lower conductive portion 24 is circumferentially spaced so as to be at a distance halfway between two adjacent upper conductive portions 22. In one embodiment, the magnetic flux conductor 4 of fig. 3 comprises 60 laminations 20 such that the rotational separation between two laminations 20 is 6 degrees. Since the lower conductive portion 24 is circumferentially offset from the upper conductive portion 22, the overall offset between the two conductive portions 22 and 24 is 3 degrees. The magnetic flux conductor 4 may alternatively be cast in one piece from powdered metal. However, the magnetic flux conductor 4 may alternatively be manufactured such that the mounting ring 18 is a single piece and each lamination 20 is a separate piece securely attached to the mounting ring 18.

Another set of magnetic flux conductors 6 is shown in fig. 5. The magnetic flux conductor 6 is magnetically connected to the south pole of the magnet 2 (not shown). The magnetic flux conductor 6 has a similar structure to the magnetic flux conductor 4 of fig. 3. The magnetic flux conductor 6 comprises a mounting ring 28 which is connected to the south pole of the magnet 2. The laminations 30 project radially outwardly from the mounting ring 28.

Fig. 6 shows the separation of the laminations 30 of the magnetic flux conductors 6 into upper and lower conductive portions 32, 34 that extend radially from the mounting ring 28. A recess 36 is defined between the upper conductive portion 32 and the lower conductive portion 34 to retain the power coil 8 (not shown). The upper conductive portion 32 is circumferentially offset relative to the lower conductive portion 34 such that the two sets of conductive portions 32 and 34 are staggered.

The magnetic flux conductors 4 and 6 of fig. 1 are oriented relative to each other such that the laminations 20 of the north pole magnetic flux conductors 4 alternate with the laminations 30 of the south pole magnetic flux conductors 6, as shown in fig. 7. The laminations 20 and 30 are suitably spaced so that little or no magnetic flux leaks through the air gaps between adjacent laminations. A space of approximately 50 thousandths of an inch is sufficient to minimize magnetic flux leakage. The upper and lower conductive portions 22 and 24 of the north pole laminations 20 are interleaved with the upper and lower conductive portions 32 and 34 of the south pole laminations 30 such that the upper conductive portion 22 of each north pole lamination 20 is vertically aligned with the lower conductive portion 34 of the south pole lamination 30. Similarly, the lower conductive portion 24 of each north pole lamination 20 is vertically aligned with the upper conductive portion 32 of the south pole lamination 30. Fig. 7 shows a side view of three north pole laminations 20 and three south pole laminations 30.

According to an embodiment of the invention, the power coil 8 has an electrical conductor 10 which carries the power generated or required by the motor/alternator. For example, once north pole magnetic flux conductor 4 and south pole magnetic flux conductor 6 are assembled around magnet 2 (see fig. 1), power coils are wound into recesses 26, 36. The power coil 8 may alternatively be wound from copper foil which fits into the recess with an insulating layer (not shown) between the windings, or made from windings of insulated rectangular wire. Alternatively, the power coil may alternatively be wound with a generally round insulated wire, but with a lower fill factor than with platinum or rectangular wire. Optionally rails of "U" shaped insulating material (not shown), for example, rest in the notches 26, 36, wherein the power coil 8 is wound to generally prevent or reduce the possibility of the power coil 8 shorting to the magnetic flux conducting laminations 20, 30.

The stator 1 of the motor/alternator has been described so far. To function as a motor or alternator, the device includes a rotor that provides input rotation and torque when operating as an alternator and that transmits rotation and torque when operating as a motor. Figure 8 shows the rotor 37 of the motor/alternator. The rotor 37 includes a rotor housing 38 mounted on a shaft 40 that rotates in bearings 42. According to an embodiment of the invention, the shaft 40 is driven by the device when the device is used as a motor, or the shaft drives the device when the device is used as an alternator. Attached to the interior of the rotor housing 38 is a plurality of flux switches 44. One embodiment includes 60 flux switches 44 attached to the interior of rotor cover 38 at 6 degree intervals.

Fig. 9 shows a cross-sectional side view of a motor/alternator according to an embodiment of the present invention. Mounted to the rotor housing 38 is a flux switch 44 that rotates with the rotor 37. The stator 1 comprises magnets 2 which provide a magnetic field with north poles facing upwards and south poles facing downwards. Flux conducting laminations 4 and 6 are in contact with magnet 2. The magnetic flux conductors 4 and 6 conduct the magnetic field very efficiently from the magnet 2 so that substantially all of the magnetic flux from the magnet 2 is directed through the magnetic flux conductors 4 and 6. The magnetic flux conductors 4 and 6 include notches 26 (not shown) and 36 into which the power coil 8 is mounted. The flux switch 44 contacts the flux conductors 4 and 6 to complete the magnetic circuit and conduct the magnetic flux from the magnet 2. The magnetic circuit defined by the magnetic flux conductors 4 and 6 and the magnetic flux switch 44 surround the power coil 8 such that a change in the magnetic field passing in the circumference of the power coil 8 induces an EMF voltage in the power coil, and the device functions as an alternator.

The method of inducing a voltage in the power coil 8 by a change in the magnetic field in the flux conductors 4 and 6 and the flux switch 44 can be best understood with reference to fig. 10 and 11. Fig. 10 shows a portion of the stator 1 and the magnetic flux switch 44 when the rotor 37 is in the first position. In fig. 10, magnetic flux switch 44 contacts upper conductive portion 22 of north pole magnetic flux conductor laminate 20 and lower conductive portion 34 of south pole magnetic flux conductor laminate 30. Magnetic flux from magnet 2 is directed radially outward through north pole flux conductor laminations 20 by upper conductive portion 22, then downward through flux switch 44, and finally radially inward along south pole flux conductor laminations 30 through lower conductive portion 34 where the magnetic flux reenters the south pole of magnet 2. When the rotor 37 rotates, the magnetic flux switch 44 passes through the magnetic flux guiding parts 22 and 34, and temporarily contacts the laminations 20 and 30 to form the magnetic circuit.

Fig. 11 shows a portion of the stator 1 and flux switches 44 in a configuration that occurs at a time after the configuration shown in fig. 10 (after 3 degrees of rotation in one embodiment). As the rotor 37 rotates, the magnetic flux switch 44 advances from one pair of magnetic flux conducting portions 22 and 34 to the next pair 22 and 32. In the configuration shown in fig. 11, magnetic flux from magnet 2 is directed radially outward through north pole flux conducting laminations 20. However, as the magnetic flux portion exits the laminations 20, it is directed downwardly through the lower conductive portion 24 of the laminations 20. The magnetic flux then enters the bottom of the flux switch 44 and is directed upward through the flux switch 44. At the top of flux switch 44, the magnetic flux enters upper conductive portion 32 of south pole flux conducting laminations 30. The magnetic flux is then directed downward through flux conducting laminations 30 and then re-enters the south pole of magnet 2. In the configuration shown in fig. 11, the magnetic flux follows a path defining a "figure 8".

The main difference between the configurations shown in fig. 10 and 11 is that the magnetic flux passes within the circumference of the power coil 8. In fig. 10, the magnetic flux passes once in the periphery of the power coil 8 in the upward direction following the passage moving around the power coil 8 in the clockwise direction. In contrast, the structure shown in fig. 11 is such that the magnetic flux follows a "figure 8" path around the power coil 8. The magnetic flux path passes once upward through the power coil 8 near the center, then downward through the inside, then upward to the outside of the circumference of the power coil 8, and then downward through the inside again. The sum of the magnetic fluxes at the positions shown in fig. 11 is the magnetic flux in one pass in the upward direction minus two passes in the downward direction, which is equal to one pass in the downward direction. In one embodiment, every 3 degrees of rotation of flux switch 44 moves between the pair of laminations 20 and 30, the net flux passing within the circumference of power coil 8 reverses direction and an AC voltage is induced in power coil 8. The AC power generated in the power coil is then optionally rectified to DC power using standard techniques familiar to those of ordinary skill in the art upon reading this disclosure.

If the device is operated as a motor, an AC current is applied to the power coil 8 and the magnetic field surrounding the power coil 8 passes through the flux switch 44. Referring to fig. 11, when current flows out of the page through the power coil 8, the induced magnetic field around the power coil 8 is in a counter-clockwise direction, so that the magnetic field in the flux switch 44 is in an upward direction, enhancing the magnetic flux present at that location. When the direction of the current in the power coil 8 is reversed, the induced magnetic flux now reverses weakening the magnetic flux density at the location shown in fig. 11, but intensifies the magnetic flux density at the next location as shown in fig. 10. The flux switch is physically attracted to complete the flux circuit, the greater the flux, the stronger the attraction. Once the motor is rotating at a speed synchronized with the electrical frequency, the flux switch 44 is strongly attracted to the pair of flux conducting parts 24 and 32, or 22 and 34, as they approach. Then, as it leaves, the attraction weakens and the attraction to the next pair 24 and 32 or 22 and 34 increases. In this embodiment, the direction of rotation of the motor from a stationary state is indeterminate, since clockwise rotation and counterclockwise rotation are equally possible. Once the motor rotates in a certain direction, it will continue to rotate in that direction exactly at the frequency of the AC current in the power coil 8. If the motor's drag torque reaches a critical threshold, the motor will simply stall. In these respects, embodiments of the present invention behave much like a synchronous motor. Embodiments of the present invention do not resemble a synchronous motor in that there is no repulsive force because the flux switch 44 is not a magnet. There is a simple small and large attraction from one location to the next, rather than repelling from one location and attracting to the next.

Embodiments of the present invention benefit from being encapsulated (filled with epoxy) to maintain dimensional stability between the magnetic flux conductors 20, 30 and the magnetic flux switch 44. According to an embodiment of the invention, all components are solid and durable, and therefore do not require maintenance. Furthermore, there is only movement between the stator 1 and the rotor 37, so that in the final assembly only two parts are required, the fully encapsulated stator 1 and the fully encapsulated rotor 37. Fig. 12 shows the encapsulated stator 1 assembly and the encapsulated rotor 37 assembly.

The frequency of the voltage in the power coil 8 is the same as the frequency of the magnetic field reversal. In the illustrated arrangement, there are 60 flux conducting laminations 20 attached to the north pole and 60 flux conducting laminations 30 attached to the south pole. Thus, for each rotation of the rotor, the magnetic field reverses 60 times. This corresponds to a 60 pole alternator, although the device is obtained with a single magnet and is optionally housed in a much smaller physical space than prior art alternators having 60 poles. The device is optionally designed with a larger number of flux conducting laminations 20, 30 so that the number of poles is increased. One design consideration is that the laminations should generally be spaced sufficiently from each other to minimize magnetic flux leakage between the laminations. According to one embodiment, the laminations are separated from each other by at least 0.05 inches to minimize magnetic flux leakage. Embodiments of the present invention use 60 magnetic flux switches 44 that are positioned every 6 degrees around the rotor housing 38 so that they both contact similar pairs of north and south pole laminations 20, 30 at the same time.

The device shown and described has an output frequency equal to 60 times the rotational speed of the rotor. For a rotor speed of 100RPM, the output frequency will be 6000 cycles per minute, or 100 Hz. Compared to a typical 6 pole alternator according to the prior art, which has an output frequency of 10Hz for the same rotor speed. Due to the high electrical frequency at a given rotational speed, the device operates at a much higher voltage than prior art motors and alternators operating at the same rotational speed. The voltage is proportional to the rate of change of the magnetic flux. Thus, for a given magnetic field strength, the rate of change increases as the frequency and voltage increase proportionally. This provides several advantages over typical prior art motors and alternators. First, the current flowing through the output coil is reduced by a factor of 10 due to the 10 folds increasing the voltage, so that the resistive loss in the coil is reduced by a factor of 100, since the resistive loss is equal to the square of the current multiplied by the resistance. Alternatively, the device may have fewer wire turns in the output coil and produce the same output voltage and current as typical prior art devices. By reducing the length (number of turns) of the wire by a factor of 10, the cost of the coil is also reduced by a factor of 10, and the resistive losses are reduced by a factor of 10. The loop shape of the output coil also selectively reduces impedance losses in the windings, thereby providing additional efficiency gains.

The increase in frequency and voltage allows for a very high power density of the device. The power density of the apparatus according to embodiments of the invention is approximately 10 times higher than that of a typical prior art 6 pole motor or alternator. In other words, for a given power rating, the device is optionally packaged in 1/10's space, which is the only space required by a typical prior art motor or alternator. This makes the device more attractive for use where space or weight is important.

The prior art alternators can be rotated at higher rotational speeds to obtain the advantages associated with those described in the two paragraphs above. However, in prior art alternators, core losses would render such modes of operation inefficient. Significant reductions in core losses according to embodiments of the present invention enable higher electrical frequencies. The core losses are caused by hysteresis when the magnetic field reverses in the material, and eddy currents induced in the electrically conductive material when the magnetic field changes in the material. Since the magnetic flux conductor 20, 30 material does not experience hysteresis, the only loss is due to eddy currents caused by the magnetic flux increasing and then decreasing (but never reversing). In this way, a material like powdered iron works well as a magnetic flux conductor, since eddy currents in powdered iron are small compared to other materials of the same permeability.

Since the magnetic flux is reversed only in the flux switch 44, hysteresis loss is generated only in a small portion of the magnetic path, so that hysteresis loss is greatly reduced. Because flux switches 44 are so small, they are selectively optimized to minimize hysteresis and eddy current losses. The flux switch 44 is optionally made of laminated steel to minimize losses. Because of their small size, it is economical to alternatively form the flux switches 44 from metallic glass.

The above-described efficiency improvements and higher frequencies of the motor/alternator according to embodiments of the present invention help produce such a dramatic improvement over prior art motor/alternators. The prior art motor/alternator is not effective at such high frequencies because the core losses are dramatically increased due to hysteresis and eddy currents. The motor/alternator according to embodiments of the present invention not only provides a geometry that fits many poles in a small space, which allows for high electrical frequencies at moderate rotational speeds, but also provides a significant reduction in core losses, making high frequency motor/alternators more practical.

Since the magnet 2 is optionally a permanent magnet 12, an electromagnet 14, or a combination of both, the field strength can be varied as desired. This allows the device to be used as an infinitely variable voltage controller. Increasing the magnetic field at slow rotation and decreasing the magnetic field at fast rotation keeps the voltage constant, so that no gearbox or other transmission is required for use with the device. This infers a lot of use of the device. For example, when used as a generator connected to a flywheel, it can alternatively be operated as a direct drive generator and output a constant voltage without the need for a gearbox. Another use of a variable magnetic field is to operate in reverse to the above, reducing the magnetic field during start-up to make rotation easier, and then increasing the magnetic field as the turbine runs faster to act as a braking system; such a constant speed, variable output wind generator is possible. This saves considerable costs and maintenance problems for the wind turbine.

Since one embodiment of the motor/alternator of the present invention is an efficient 60 pole motor/alternator, cogging torque is reduced due to the even distribution of poles around the rotating tunnel. Instead of the 6 poles in a conventional motor alternator creating six points in the rotating channel (as an alternator) that must be overcome by the external torque machine, there are 60 poles through embodiments of the present invention, thus 60 points in rotation. Embodiments of the present invention eliminate torque around full rotation by only a small increase every 3 degrees instead of the large increase every 30 degrees of the conventional 6 pole motor/alternator.

The second specifically described embodiment of the invention further optimizes the operation as an alternator by minimizing the amount of material that experiences hysteresis. Fig. 13 shows a cross-sectional view according to this embodiment, similar to the view shown in fig. 9 of the first embodiment. Many elements of the second embodiment are the same as those of the first embodiment, such as the magnet 2, the power coil 8, and the rotor cover 38. A second embodiment of the invention utilizes deeper recesses 50 in north pole flux conductor laminations 52 and south pole flux conductor laminations 51 that house power coils 8, and smaller flux switches 54 that now rotate in recesses 50. North magnetic flux conductor laminate 52 has an elongated upper conductive portion 56 and an elongated lower conductive portion 58. Although not shown in fig. 13, south pole flux conductor 51 similarly has a longer upper conductive portion 60 and a longer lower conductive portion 62.

Fig. 14 and 15 show cross-sectional views of two north pole flux conductor laminations 52, one south pole flux conductor lamination 51 and one flux switch 54. As can be seen in these figures, the magnetic flux conductor laminations 51, 52 are flat and there is no offset between the upper conductive portions 56, 60 and the lower conductive portions 58, 62 of the laminations 51, 52 as in the first embodiment. It can also be seen that the magnetic flux switch 54 is angled so that it contacts one upper conductive portion 56, 60 of one pole and an adjacent lower conductive portion 62, 58 of the opposite pole. In the second embodiment, the magnetic flux conductors 51, 52 and the magnetic flux switch 54 are flat in shape, which will greatly facilitate manufacturing. Fig. 14 and 15 show the sequence as flux switch 54 rotates through flux conducting laminations 51, 52. In fig. 14, the magnetic flux switch connects the north pole upper conductive portion 56 to the adjacent south pole lower conductive portion 62. In fig. 15, after a while, the flux switch connects the south pole upper conductive portion 60 with the adjacent north pole lower conductive portion 58 so that the magnetic field reverses direction around the power coil 8 between fig. 14 and 15.

One advantage of the second embodiment is the small flux switch 54. Since the flux switch 54 is the only part of the embodiment that experiences the magnetic field, the smaller the flux switch, the smaller the hysteresis loss. Further, due to the small magnetic flux switch of a simple shape, a magnetic flux switch made of a special material such as metallic glass which experiences particularly small hysteresis loss is economical. The flux switch 54 can be reduced in size until flux leakage between the opposing flux conductors 51, 52 is problematic due to the narrow recess 50.

A third particularly described embodiment of the invention is a three-phase motor/alternator. The three-phase embodiment described herein is optimized for low hysteresis losses and uses a flux conductor and flux switch arrangement similar to that of a unidirectional ac generator as described in the second particularly described embodiment of the invention. Other layouts of the three-phase type are possible (such as an embodiment similar to the first one specifically described herein, or an embodiment with an internal rotor), and are considered to be included within the scope of the present invention.

A third embodiment of the three phases of the present invention comprises a stator 101 shown in fig. 16 and a rotor 160 shown in fig. 21. Fig. 16 shows the components of the stator 101. Stator 101 has a ring magnet 102, a set of north pole magnetic flux conductors 104, a set of south pole magnetic flux conductors 106, and three power coils 108, 110, 112. North and south magnetic flux conductors 104 and 106 are in direct contact with the magnet 102. Similar to the previous embodiments, the magnetic flux conductors are optionally made of a material that readily conducts magnetic fields and repels eddy currents, such as powdered iron. The magnetic flux conductors 104 and 106 direct the magnetic field of the magnet 102 toward the power coils 108, 110, 112. The power coils 108, 110, 112 are electrical coils in which a voltage is generated when the device is used as an alternator. When used as a motor, the power coils 108, 110, 112 provide voltage and current to power the device. Each power coil 108, 110, 112 includes an electrical lead 114, 115, 116, respectively, that collects output power when the device is operating as an alternator or provides power when the device is operating as a motor. The power waveform of each power coil 108, 110, 112 is 120 degrees out of phase with the other two. When combined, the outputs of the three power coils 108, 110, 112 produce three-phase power. The magnet 102 in the three-phase embodiment is similar in all respects to the magnet 2 in the single-phase embodiment (as seen in fig. 2), including permanent magnets, electromagnets, or a hybrid magnet form of both.

The magnetic flux conductor 104 connected to the north pole (not shown) of the magnet 102 may alternatively be formed as a single piece as shown in fig. 17. The magnetic flux conductor includes a mounting ring 118 that provides structural support for the magnetic flux conductor. The mounting ring 118 contacts the north pole side of the magnet 102 and holds the magnet 102 in its proper position. Attached to mounting ring 118 are a plurality of magnetic flux conductor laminations 120. Laminations 120 direct the magnetic field from magnet 102 to the appropriate location. Each lamination 120 extends radially outward from mounting ring 118 and is separated into four conductive portions.

Fig. 18 shows a single north pole flux conductor lamination 120. The lamination 120 is a flat piece having four conductive portions, here depicted in descending order, as shown in fig. 18. It should be noted that for the sake of clarity, the terms "top", "upper", "lower" and "bottom" are used as such with reference to their position in the figures. The use of descriptive labels herein and elsewhere in the specification is intended to aid in clearly distinguishing between similar elements and is not intended to limit the invention in any way. The top conductive portion 124 extends directly radially outward from the mounting ring 118. An upper conductive portion 126 extends downward from the top conductive portion 124. Between the top and upper conductive portions 124 and 126, there is a notch 128 defined in each lamination 120 to retain the power coil 108 (not shown). The lower conductive portion 130 extends downward from the upper conductive portion 126. Between the upper and lower conductive portions 126 and 130, there is a recess 132 defined in each lamination 120 to retain the power coil 110 (not shown). The bottom conductive portion 134 extends downward from the lower conductive portion 130. Between the lower and bottom conductive portions 130 and 134, there is a notch 136 defined in each lamination 120 to retain the power coil 112 (not shown). In one embodiment, the magnetic flux conductor 104 of fig. 17 includes 60 laminations 120 such that the separation between two laminations 120 is 6 degrees. The magnetic flux conductor 104 may alternatively be cast as a single piece from powdered metal. However, the magnetic flux conductor 104 may alternatively be manufactured such that the mounting ring 118 is a single piece and each lamination 120 is a separate piece securely attached to the mounting ring 118.

Another set of magnetic flux conductors 106 is shown in fig. 19. Magnetic flux conductor 106 is magnetically coupled to the south pole of magnet 102. The magnetic flux conductors 106 are simply reversed from the magnetic flux conductors 104 of fig. 17 with a similar construction. The magnetic flux conductor 106 includes a mounting ring 138 that is attached to the south pole of the magnet 102. The laminations 140 project radially outwardly from the mounting ring 138.

Fig. 20 shows a single magnetic flux conducting lamination 140 of magnetic flux conductor 106. The laminations 140 are flat pieces and are separated into four conductive portions depicted in descending order as shown in fig. 20; a top conductive portion 144, an upper conductive portion 146, a lower conductive portion 150, and a bottom conductive portion 154. The bottom conductive portion 154 extends directly radially outward from the mounting ring 138. Notches 148, 152, and 156 are defined between conductive portions 144, 146, 150, 154 as shown, and hold power coils 108, 110, and 112, respectively (not shown).

Magnetic flux conductors 104 and 106 are oriented relative to each other such that laminations 120 of north magnetic flux conductor 104 alternate with laminations 140 of south magnetic flux conductor 106. Laminations 120 and 140 are separated such that little or no magnetic flux leaks through the air gaps between adjacent laminations.

So far, only the stator 101 of the motor/alternator of the third specifically described embodiment has been discussed. Fig. 21 shows the rotor 160 of the motor/alternator. The rotor 160 includes a rotor housing 162 mounted on a shaft 164 that rotates in bearings 166. According to an embodiment of the present invention, shaft 164 is driven by the apparatus described herein when the apparatus is used as a motor, or the shaft drives the apparatus when the apparatus is used as an alternator. Attached to the interior of rotor cover 162 are a plurality of three rows of flux switches 168, 170, 172 arranged in a circle one below the other, referred to in descending order as shown in fig. 21 as high row flux switch 168, middle row flux switch 170 and low row flux switch 172. It should be noted that for the sake of clarity, the words "high", "intermediate", and "low" are used with reference to their positions in the figures. The use of descriptive labels herein and elsewhere in the specification is intended to aid in clearly distinguishing between similar elements and is not intended to limit the invention in any way. One embodiment includes 60 flux switches 168, 170, 172 in each row attached to the interior of rotor cover 162 at 6 degree intervals. Each row is rotatably offset from the other two rows by 2 degrees. After the rotor 160 is positioned on the assembled stator 101, the flux switches 168, 170, 172 are installed through slots (not shown) in the rotor cover 162. High flux switch 168 rotates through notches 128, 148 in magnetic flux conducting laminations 120, 140. The middle flux switch 170 rotates through the notches 132, 152 and the lower flux switch 172 rotates through the notches 136, 156 in the flux conducting laminations 120, 140. Operation of flux switches 168, 170, 172 in conducting magnetic flux between north and south pole flux conducting laminations 120, 140 generates three-phase electrical power, as best shown in fig. 22, 23, 24 and 25.

Fig. 22, 23, 24 and 25 show a set of three magnetic flux switches: high magnetic flux switch 168, middle magnetic flux switch 170, and low magnetic flux switch 172 rotate through a sequence of 3 degree arcs or half of a circle. The rotation in this series of figures is clockwise as viewed from above. Shown are power coils 108, 110 and 112, two north magnetic flux conducting laminations 120 having top 124, upper 126, lower 130 and bottom 134 conducting portions, and two south magnetic flux conducting laminations 140 having top 144, upper 146, lower 150 and bottom 154 conducting portions. In each figure, only the conductive parts mentioned in the description of the figure are marked. The arrows in flux switches 168, 170 or 172 and in flux conductors 120 and 140 indicate the location and direction of peak flux flow. The arrows on the power coils 108, 110 or 112 indicate the direction of the peak current. For purposes of illustration, current is defined as positive when current flows to the right as shown and negative when current flows to the left as shown.

In fig. 22, high flux conductor 168 magnetically connects top conductive portion 144 of south pole magnetic flux lamination 140 to upper conductive portion 126 of north pole magnetic flux lamination 120, causing the magnetic flux to rotate in a counterclockwise direction about power coil 108, inducing current to flow to the left, or negative, in power coil 108. Depending on the details of the construction of the flux conducting laminations 120, 140 and the flux switches 168, 170, 172, optionally also some small amount of current induced in the two power coils 108, 110, 112 (coils 110 and 112 in this figure) is not mentioned, which is the case if a standard three-phase power output is required. For purposes of illustration, only peak current and magnetic flux are shown and discussed.

Fig. 23 is the same view as fig. 22 after being rotated 1 degree. Middle flux switch 170 magnetically connects upper conductive portion 126 of north pole flux lamination 120 to lower conductive portion 150 of south pole flux lamination 140, causing the magnetic flux to rotate in a clockwise direction about power coil 110, inducing current to flow to the right, or positive direction, in power coil 110.

Fig. 24 is the same view as fig. 22 after being rotated 2 degrees. Low-flux switch 172 magnetically connects lower conductive portion 150 of south magnetic flux lamination 140 to bottom conductive portion 134 of north magnetic flux lamination 120, causing the magnetic flux to rotate in a counterclockwise direction about power coil 112, inducing current to flow to the left, or negative, in power coil 112.

Fig. 25 is the same view as fig. 22 after being rotated 3 degrees. High flux switch 168 magnetically connects top conductive portion 124 of north pole magnetic flux lamination 120 to upper conductive portion 146 of south pole magnetic flux lamination 140, causing the magnetic flux to rotate in a clockwise direction about power coil 108, inducing current to flow to the right, or positive direction, in power coil 108, which is the opposite of fig. 22. Thus, the current is reversed in the power coil 108, completing a half-cycle after a 3 degree rotation.

The three-phase embodiment of the present invention has the advantage of directionality, i.e., forward and backward. In the single phase embodiment, the direction of rotation is indeterminate when used as a motor, but with the three phase embodiment, there is a clear path of rotation (clockwise in the embodiment shown in fig. 23-26). By appropriate control, the direction of rotation is selectably reversed by switching the relative phases of power supplied to any two of the power coils 108, 110, 112. Furthermore, it should be noted that in the third particularly described embodiment of the invention, the motor/alternator has 60 poles and three phases, but still uses only one magnet.

A benefit of embodiments according to the invention is the low inertia of the rotor. Since only the flux switches rotate, they can alternatively be made very light to use, wherein the inertia of the rotor is a critical issue. To further reduce the inertia of the rotor, the structure of the rotor can be reversed so that the magnets are outside the stator and the power coils are inside. This allows the flux switch to be located inside the rotor, where the rotor has a lower moment of inertia and the rotor is lighter.

The single phase inner rotor variation of the device is described as a fourth particularly described embodiment of the invention. Although a single phase apparatus is described in the fourth embodiment, it is understood that the inner rotor structure can be equally applied to a single phase apparatus. Fig. 26 shows an exploded view of a stator 201 of a fourth embodiment of the present invention. Stator 201 has a ring magnet 202, a set of north pole magnetic flux conductors 204, a set of south pole magnetic flux conductors 206, and power coils 208 similar to other embodiments. Magnetic flux conductors 204 and 206 direct the magnetic field of magnet 202 on the outside towards power coil 208 on the inside.

The magnetic flux conductors 204 and 206 may alternatively be formed as a single piece, as in the other three embodiments. The magnetic flux conductors 204, 206 include mounting rings 218, 228 that provide structural support for the magnetic flux conductors 204, 206 and hold the magnet 202 in place. Attached to mounting rings 218, 228 are a plurality of flux conductor laminations 220, 230, respectively. Laminations 220, 230 conduct the magnetic field from magnet 202 to the appropriate location.

Magnetic flux conductors 204 and 206 are oriented relative to each other such that laminations 220 of north magnetic flux conductor 204 alternate with laminations 230 of south magnetic flux conductor 206. Laminations 220 and 230 are suitably spaced apart so that little or no magnetic flux leaks through the air gaps between adjacent laminations.

Fig. 27 shows a rotor 237 of a motor/alternator according to a fourth embodiment of the present invention. The rotor 237 includes a rotor shaft 240 that rotates in bearings 242. Shaft 240 is driven by the apparatus in various embodiments of the present invention when the apparatus is used as a motor, or the apparatus in various embodiments of the present invention when the apparatus is used as an alternator. Mounted to the exterior of the shaft 240 are a plurality of magnetic flux switches 244. One embodiment includes 60 magnetic flux switches 244 attached to the shaft 240 at 6 degree intervals. Each magnetic flux switch 244 has a double bend in its central portion such that it connects the upper conductive portion 222, 232 with the lower conductive portion 234, 224 of the adjacent opposing pole.

Fig. 28 shows a cross-sectional view of a fourth particularly described embodiment of the invention, in which magnetic flux switch 244 and two north pole magnetic flux conducting laminations 220 and two south pole magnetic flux conducting laminations 230 are shown. Each lamination 220, 230 is separated into two conductive portions. Thus, north pole lamination 220 has an upper conductive portion 222 and a lower conductive portion 224 defining a recess 226 therebetween, and south pole lamination 230 has an upper conductive portion 232 and a lower conductive portion 234 defining a recess 236 therebetween. Flux switch 244 connects upper conductive portion 222 of north pole flux conducting lamination 220 with lower conductive portion 234 of south pole flux conducting lamination.

Fig. 29 shows a cross-sectional side view of a motor/alternator of a fourth embodiment of the present invention, similar to the view shown in fig. 9 of the first embodiment, and the view of fig. 13 of the second embodiment. Mounted to the rotor shaft 240 is a flux switch 244 that rotates with the shaft 240. The stator includes magnets 202 that provide a magnetic field such that the north poles face upward and the south poles face downward. Magnetic flux conductors 204 and 206 are in contact with magnet 202. The magnetic flux conductors 204 and 206 include notches 226 and 236 in which the power coil 208 is mounted. Magnetic flux switch 244 contacts magnetic flux conductors 204 and 206 to complete the magnetic circuit and conduct the magnetic flux from magnet 202.

The fourth embodiment shows a different geometry (rotor 237 inside, stator 201 outside, flux switch 244 double bent) than the previous embodiments of the invention. The newly described geometry helps to reduce the inertia of the rotor. Still other geometries are possible and still be within the scope of the invention, and these alternative geometries may provide some advantages. For example, a layout in which both the stator and rotor terminate in flat discs abutting each other is possible and optionally required to facilitate construction or to generate electricity across the membrane. In this way, the rotor is not on the inside or outside of the stator, but on the stator face. Another possible form is as a linear motor/alternator in which the magnetic flux conductors are arranged in a straight line and the magnetic flux switches are attached to a reciprocating shaft. Such a linear alternator would be useful, for example, for use with Stirling motors. The above and other geometries and variations of layouts intended to produce the same or similar electromagnetic effects are included within the scope of the present invention. The specifically described embodiments illustrate some of the variations that the invention may encompass, but are in no way intended to limit the scope of the invention.

It should be noted that one difference between embodiments of the present invention and prior art motors and alternators is the basic orientation of the magnetic field and motion. In prior art motors and alternators, the axis of rotation, the orientation of the magnetic field and the line of relative movement between the stator and the rotor are all perpendicular to each other. In an embodiment of the invention, the axes of orientation and rotation of the magnetic field are parallel and each perpendicular to the line of relative motion between the rotor and stator. This difference optionally allows embodiments of the present invention to be used where prior art motors and alternators are not practical, such as to generate or transmit power across membranes as described above.

The motor of the invention in the particularly described embodiment described above comprises several components. These components include a magnet (e.g., element 2 in fig. 1), an electrical conductor (e.g., element 8 in fig. 1) arranged in a loop, a plurality of magnetic flux conductors (e.g., elements 4 and 6 in fig. 1) that direct magnetic flux from the magnet through the electrical conductor, wherein a first set of magnetic flux conductors (e.g., element 4 in fig. 1) direct magnetic flux through the electrical conductor in a first direction and a second set of magnetic flux conductors (e.g., element 6 in fig. 1) direct magnetic flux through the electrical conductor in a second direction, and a switch (e.g., element 44 in fig. 8) for alternately connecting and disconnecting the first and second sets of magnetic flux conductors. The switch may be selectively attached to a rotor of the motor, and the urging force may be selectively applied to the rotor to induce a current to flow in the electrical conductor, or the alternating current may be selectively applied to the electrical conductor to impart movement to the rotor. It should be noted that the ring of electrical conductors and the magnets may alternatively be annular, although they may take different shapes or forms. The magnets and electrical conductors may alternatively be concentrically oriented, although other orientations are possible. If the magnet and the electrical conductor are annular and they are concentrically oriented, the magnet may alternatively have a smaller diameter than the electrical conductor and may alternatively be disposed within the periphery of the electrical conductor, or the electrical conductor may alternatively have a smaller diameter than the magnet and may alternatively be disposed within the periphery of the magnet. The magnetic flux conductors may alternatively be formed of powdered iron, although other materials may work well. The switch may alternatively be formed from laminated steel or metallic glass, although other materials may work well for the switch. The electrical machine of the invention may optionally comprise three electrical conductors, each arranged to form a loop, wherein the magnetic flux conductor directs magnetic flux from the magnet through the loops of all three electrical conductors. In such a case, the motor will comprise a switch for alternately connecting and disconnecting the magnetic flux conductors by all three electrical conductors, so that the motor operates as a three-phase motor. The magnets used in the motor of the present invention may alternatively be permanent magnets, electromagnets or hybrid magnets comprising permanent and electromagnets juxtaposed so that the magnetic fields of the permanent and electromagnets are superimposed.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes in these embodiments may be made without departing from the scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments described and illustrated herein.

Claims (24)

1. An electric machine, comprising:

a magnetic body which is provided with a magnetic body,

the electrical conductor is arranged as a loop and,

a plurality of magnetic flux conductors that direct magnetic flux from the magnet through the ring of electrical conductors, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction, and

a switch for alternately connecting and disconnecting pairs of said sets of north and south magnetic flux conductors, wherein each pair comprises one north and one south magnetic flux conductor.

2. The motor of claim 1, wherein the switch is attached to a rotor of the motor.

3. The electric machine of claim 2 wherein a motive force is applied to the rotor to induce current to flow in the electrical conductors.

4. The motor of claim 2 wherein an alternating current is applied to the electrical conductors to impart motion to the rotor.

5. The motor of claim 1 wherein both said magnet and said electrical conductor are annular.

6. The electric machine of claim 5 wherein said magnet and said electrical conductor are concentrically oriented.

7. The electric machine of claim 6 wherein said magnets have a smaller diameter than said electrical conductor and are disposed within the periphery of said electrical conductor.

8. The electric machine of claim 6 wherein said electrical conductor has a smaller diameter than said magnet and is disposed within the periphery of said magnet.

9. The electric machine of claim 1, wherein the magnetic flux conductors are formed of powdered iron.

10. The electric machine of claim 1, wherein the switch is formed of laminated steel.

11. The electric machine of claim 1, wherein the switch is formed from metallic glass.

12. The electric machine of claim 1, further comprising two additional electrical conductors, each arranged as a loop, wherein the plurality of magnetic flux conductors direct magnetic flux from the magnet through the loops of all three electrical conductors, and further comprising a plurality of switches for alternately connecting and disconnecting the magnetic flux conductors through all three electrical conductors so that the electric machine operates as a three-phase electric machine.

13. The motor of claim 1 wherein said magnets are permanent magnets.

14. The motor of claim 1, wherein the magnet is an electromagnet.

15. The motor of claim 1, wherein the magnet is a hybrid magnet comprising a permanent magnet and an electromagnet juxtaposed so that the magnetic fields of the permanent magnet and the electromagnet are superimposed.

16. A method of generating electricity, comprising:

a magnet is provided which is capable of being rotated,

an electrical conductor is provided which is arranged as a loop,

using a plurality of magnetic flux conductors to direct magnetic flux from the magnet through the ring of electrical conductors, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction, and

the magnetic flux conductor is alternately switched between an on state and an off state to induce an alternating current in the electrical conductor.

17. The method of claim 16, further comprising the steps of providing a switch on a rotor, and rotating the rotor to move the switch between the north and south magnetic flux conductors to alternately switch the magnetic flux conductors between an on and off state.

18. The method of claim 17, further comprising the step of rectifying the alternating current in the electrical conductor to direct current.

19. A method of providing motive force, comprising:

a magnet is provided which is capable of being rotated,

a first electrical conductor is provided arranged as a loop,

using a plurality of magnetic flux conductors to direct magnetic flux from the magnet through the ring of the first electrical conductor, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction,

using a switch on the rotor to switch the magnetic flux conductor between an on-state and an off-state, an

Providing an alternating current in the first electrical conductor such that the switch moves between successive north and south pole sets of magnetic flux conductors when the polarity of the alternating current changes sign.

20. The method of claim 19, further comprising the steps of:

providing a second and a third electrical conductor, each arranged as a loop,

using a plurality of magnetic flux conductors to direct magnetic flux from the magnet through the second loop of the second electrical conductor and the third loop of the third electrical conductor, wherein a north pole magnetic flux conductor directs the magnetic flux through the second and third loops in a radially outward direction and a south pole magnetic flux conductor set directs the magnetic flux through the second and third loops in a radially inward direction,

using a switch on the rotor to switch the magnetic flux conductor between an on-state and an off-state, an

Providing three-phase alternating current in the first, second and third electrical conductors such that the switch moves between successive sets of north and south magnetic flux conductors to rotate the rotor in a predetermined direction.

21. An electric machine, comprising:

the source of the magnetic flux,

the electrical conductor is arranged as a loop and,

a plurality of magnetic flux conductors that direct magnetic flux from the magnetic flux source through the ring of electrical conductors, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction, and

a switch for alternately connecting and disconnecting pairs of said sets of north and south magnetic flux conductors, wherein each pair comprises one north and one south magnetic flux conductor.

22. An electric machine, comprising:

a magnetic body which is provided with a magnetic body,

a ring of an electrically conductive material is provided,

a plurality of magnetic flux conductors that direct magnetic flux from the magnet through the ring of electrical conductor material, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction, and

a switch for alternately connecting and disconnecting pairs of said sets of north and south magnetic flux conductors, wherein each pair comprises one north and one south magnetic flux conductor.

23. An electric machine, comprising:

a magnetic body which is provided with a magnetic body,

the electrical conductor is arranged as a loop and,

means for guiding magnetic flux from the magnet through the ring of electrical conductors, comprising first means for guiding the magnetic flux through the ring in a radially outward direction, and second means for guiding the magnetic flux through the ring in a radially inward direction, and

a switch for alternately connecting and disconnecting pairs of said first and second means for directing magnetic flux, each of which comprises one of said first means for directing magnetic flux and one of said second means for directing magnetic flux.

24. An electric machine, comprising:

a magnetic body which is provided with a magnetic body,

the electrical conductor is arranged as a loop and,

a plurality of magnetic flux conductors that direct magnetic flux from the magnet through the ring of electrical conductors, wherein a north pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially outward direction to form a first magnetic circuit and a south pole set of magnetic flux conductors directs the magnetic flux through the ring in a radially inward direction to form a second magnetic circuit, and

a switch for alternately contacting pairs of said north and south pole sets of magnetic flux conductors to complete first and second magnetic circuits, wherein one north pole magnetic flux conductor and one south pole magnetic flux conductor.