WO2017008085A1

WO2017008085A1 - An improved electric linear motor/generator

Info

Publication number: WO2017008085A1
Application number: PCT/US2016/041818
Authority: WO
Inventors: Fred E. Hunstable
Original assignee: Linear Labs, Inc.
Priority date: 2015-07-09
Filing date: 2016-07-11
Publication date: 2017-01-12

Abstract

Disclosed are various embodiments for a linear motor/generator having a unique magnetic section geometry and orientation.

Description

AN IMPROVED ELECTRIC LINEAR MOTOR/GENERATOR

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S. provisional patent application serial number 62/190,628, entitled "An Improved Electrical Linear Motor/Generator" filed on July 9, 2015, the disclosure of which is incorporated herein by reference for all purposes.

TECHNICAL FIELD

The invention relates in general to a new and improved electric motor/generator, and in particular to an improved system and method for producing linear motion from a electro-magnetic motor or generating electrical power from a linear motion input.

BACKGROUND INFORMATION

Electric motors use electrical energy to produce mechanical energy, very typically through the interaction of magnetic fields and current-carrying conductors. The conversion of electrical energy into mechanical energy by electromagnetic means was first demonstrated by the British scientist Michael Faraday in 1821.

In a traditional electric rotary motor, a central core of tightly wrapped current carrying material (known as the rotor) spins or rotates at high speed between the fixed poles of a magnet (known as the stator) when an electric current is applied. The central core is typically coupled to a shaft which will also rotate with the rotor. The shaft may be used to drive gears and wheels in a rotary machine and/or convert rotational motion into motion in a straight line.

A linear motor typically comprises a "stator" which is usually in the form of a track of flat coils made from aluminum or copper and is known as the "primary" of a linear motor. The "rotor" or "mover" takes the form of a moving platform known as the "secondary." When the current is switched on, the secondary glides past the primary supported and propelled by a magnetic field.

Although electric motors have been used for over 150 years, as the world's energy resources grow more scarce, there is a need for more efficient methods and improvements in electrical motors. SUMMARY

In response to these and other problems, there is presented various embodiments disclosed in this application, including methods and systems of increasing flux density by permanent magnet manipulation using linear magnetic tunnels. Disclosed are various embodiments for a motor/generator comprising: a rotor adapted to move along a longitudinal axis, the rotor comprising a plurality of magnetic tunnels, wherein the plurality of magnets forming each magnetic tunnel substantially have poles facing inward toward the center of the tunnel, when a stator is positioned within the tunnel, flux lines cross the tunnel from at least two directions, the linear tunnel having an entrance and an exit, wherein the magnetic field of any magnetic tunnel is of an opposite polarity to the magnetic field of an adjacent magnetic tunnel.

These and other features, and advantages, will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

It is important to note the drawings are not intended to represent the only aspects of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is an exploded view of one embodiment of a linear motor/generator according to certain aspects of the present disclosure.

Fig. 2A is a detailed isometric view of the assembled linear motor/generator illustrated in

Fig. 1.

Fig. 2B is a detailed isometric view of the assembled linear motor/generator illustrated in Fig. 1 with the back iron circuit removed for clarity.

Fig. 3A is an isometric view of a rotor/stator which may be used in the motor generator of Fig. 1.

Fig. 3B is an isometric view of the rotor/stator of Fig. 3A illustrating a central iron core and a plurality of ribs extending from the iron core where a portion of the ribs have been removed for clarity.

Fig. 3C is a detailed perspective view of a single rib of the plurality of ribs of Fig. 3A and a portion of the iron core.

Fig. 3D is a detailed section or "cut away" perspective section view of a single rib of Fig. 3C. Fig. 4A illustrates a plurality of magnets forming one embodiment of a linear magnetic tunnel.

Fig. 4B illustrates the plurality of magnets forming one embodiment of a linear magnetic tunnel of Fig. 4A from a different perspective.

Fig. 4C is a section view through a magnetic segment of the linear magnetic tunnel of Figs. 4 A and 4B.

Fig. 4D is a section view of an adjacent magnetic segment of the linear magnetic tunnel of Figs. 4 A and 4B.

Fig. 5A is a detailed isometric view of one embodiment of a magnetic linear segment with a rotor/stator portion positioned therein illustrating the direction of the flux forces generated from the magnets comprising the magnetic linear segment.

Fig. 5B is a detailed isometric view of one embodiment of a magnetic linear segment with a rotor/stator portion and a coil winding positioned therein illustrating the direction of the flux forces generated from the magnets and the direction of the current in the coil winding.

Fig. 5C is a detailed isometric view of one embodiment of a magnetic linear segment of Fig. 5B illustrating the direction of the electromotive forces generated by the magnets and the current in the coil windings.

DETAILED DESCRIPTION

Specific examples of components, signals, messages, protocols, and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to limit the invention from that described in the claims. Well-known elements are presented without detailed description in order not to obscure the present invention in unnecessary detail. For the most part, details unnecessary to obtain a complete understanding of the present invention have been omitted inasmuch as such details are within the skills of persons of ordinary skill in the relevant art. Details regarding conventional control circuitry, power supplies, or circuitry used to power certain components or elements described herein are omitted, as such details are within the skills of persons of ordinary skill in the relevant art.

When directions, such as upper, lower, top, bottom, clockwise, or counter-clockwise are discussed in this disclosure, such directions are meant to only supply reference directions for the illustrated figures and for orientation of components in the figures. The directions should not be read to imply actual directions used in any resulting invention or actual use. Under no circumstances, should such directions be read to limit or impart any meaning into the claims.

Fig. 1 is an exploded perspective view of a linear motor/generator 100. Fig. 2A is the linear motor/generator 100 in an assembled configuration illustrating a first portion of a back iron circuit 102. Fig. 2B illustrates the motor/generator 100 in the assembled configuration of Fig. 2B, but with the back iron circuit 102 removed for clarity.

Turning to Figs. 1, 2A and 2B, the linear motor/generator 100 comprises a back iron circuit 102, a magnetic tunnel 104 sized to fit within the back iron circuit 102, a coil assembly or "stator" 106 having a plurality of ribs 108 extending laterally from a core 110, and a plurality of coil windings 112 sized to fit within a plurality of slots 114 defined by the plurality of ribs 108 of the coil assembly 106. All the primary components are aligned to a central or longitudinal axis 101 which also defines a longitudinal or axial direction.

For purposes of convenience, it will be assumed that the magnetic tunnel 104 and the back iron circuit 102 moves relative to the structure forming the coil assembly 106 (which also contains the plurality of coil windings 112). Thus, the magnetic tunnel 104 and the back iron circuit 102 is the rotor, mover, or secondary. The coil assembly 106, including the plurality of coil windings 112 is thus, the stator or primary of the motor/generator 100. In other configurations, which are within the scope of this invention, the magnetic tunnel 104 and back iron circuit 102 may be the stator or primary. In such configurations, the coil assembly would then be the rotor, mover, or secondary of the motor/generator 100. Thus, it does not matter which components actually move as long as relative movement occurs between the stator and rotor.

For purposes of this application the term "back iron" may refer to iron, any ferrous compound or alloy, such as stainless steel, any nickel or cobalt alloy, or any laminated metal comprising laminated sheets of such material.

Thus, when assembled as illustrated in Fig. 2A, the back iron circuit 102 physically surrounds the magnetic tunnel 104. In certain embodiments, the back iron circuit may be used as part of the magnetic flux path. The back iron material channels the magnetic flux produced by the magnetic tunnel 104 through the back iron material (as opposed to air) to reduce the reluctance of the magnetic circuit. In certain embodiments, therefore, the amount or thickness of the magnets forming the tunnel(if permanent magnets are used) may be reduced when using the appropriately designed back iron circuit.

In other embodiments, the back iron circuit 102 have slots (not shown) defined therein to allow the passage of control wires and/or electrical conductors as well as allowing heat to escape.

Fig. 3 A is a perspective view of the coil assembly 106 showing the plurality of ribs 108 extending laterally from the core 110. Fig. 3B is a perspective view of the coil assembly 106 with a portion of ribs 108 removed for clarity. With a portion of the ribs 108 removed, several of the individual coil windings of the plurality of coil windings 112 are visible. As illustrated, the coil windings 112 may be positioned about the core 110 of the coil assembly 106 and are longitudinally positioned along the core 110 within the slots 114 formed by the ribs 108 to create a coil structure 118. Thus, the coil structure 118 comprises both the stator structure 106 and the plurality of coil windings 112.

Each individual coil or coil winding 112a in the coil structure 118 may be made from a conductive material, such as copper (or a similar alloy) wire and may be constructed using conventional winding techniques known in the art. In certain embodiments, concentrated windings may be used. In certain embodiments, the individual wound coils 112 may be essentially toroidal, cylindrical or rectangular in shape being wound around the coil core 110 having a center opening sized to allow the individual coil 112a to be secured to the core 110. In certain embodiments, the individual coils 112a may be connected to each other in series. In yet other embodiments, multiple phase windings may be used. For instance, two adjacent coils may be phase A coils, the next two adjacent coils may be phase B coils, and the next two adjacent coils may be phase C coils. This three phase configuration would then repeat for all individual coils 112 within the coil structure.

By positioning the individual coils 112 within the slots 114 formed by the ribs 108, the coils are surrounded by the more substantial heat sink capabilities of the ribs which, in certain embodiments, can be can incorporate cooling passages directly into the material forming the ribs. This allows much higher current densities than conventional motor geometries. Additionally, positioning the plurality of coils 112 within the slots 114 and between the ribs 108 reduces the air gap between the coils or coil windings. By reducing the air gap, the coil structure 118 can contribute to the overall force produced by the motor or generator. As will be explained below, a longitudinally extending frame extends from each rib and also contributes to the force. Thus, all portions of the stator structure 106 contribute to the overall force developed by the system. The number of individual coils 112 can be any number that will physically fit within the desired volume and of a conductor length and size that produces the desired electrical or mechanical output as known in the art.

As discussed above, the core 110 may be made out of iron or back iron materials so that it will act as a magnetic flux force concentrator. However, other core materials maybe used when design considerations such as mechanical strength, reduction of eddy currents, cooling channels, etc. are considered. Back iron materials may be iron, an iron alloy, laminated steel or iron.

An embodiment of an individual rib 108a and a small portion of the stator core 110a are illustrated in Fig. 3C. In the illustrated embodiment, the rib 108a laterally extends from the core 110a in all directions. Thus, in this embodiment, each rib 108a is rectangular in shape. Adjacent ribs (not shown) are positioned at predetermined longitudinal intervals along the entire core 110. In some embodiments, an exterior frame 116 couples to an exterior edge or portion of the rib 108a and extends from the exterior edge outward in a longitudinal direction to reduce the air gap between adjacent ribs. In certain embodiments, the ribs 108a and exterior frames 116 may be made from a material similar to the material forming the core 110, for example, iron or laminated steel. Fig. 3D is a partial section or cut away perspective view of the individual rib 108a and portion of the stator core 110a of Fig. 3C which illustrates the overall section shape of the exterior frame 116. Specifically, the exterior frame 116 extends from an exterior edge or portion of the rib 108a in two directions which are parallel to the longitudinal axis 101. In this specific embodiment, the exterior frame cross-sectional thickness is larger proximate to the rib 108a and tapers slightly as it extends longitudinally away from the rib 108a.

Although the core 110 is represented as a single core, in order to manufacture the coil structure using conventional winding techniques, the core 110 may be formed from a plurality of interlocking pieces. Thus, the coil structure 118 may be made from wrapping a coil winding about a first portion of the coil structure (comprising a first portion of the core and a first rib), then coupling a next portion of the coil structure (comprising an adjacent portion of the core and an adjacent rib) to the first portion. Once the coupling is completed, the next coil winding may be wrapped around the adjacent portion of the new rib. This, process may continue until the coil structure is built up to a predetermined longitudinal length (which depends on design characteristics).

Fig. 4A is a detailed perspective view of the magnetic tunnel 104 taken from a first perspective to show a first side of the magnetic tunnel. Fig. 4B is a detailed perspective view of the magnetic tunnel 104 taken from a second perspective to show a second side of the magnetic tunnel. As discussed above, in certain embodiments the magnetic tunnel 104 (and the back iron circuit 102) may be the rotor, mover or the secondary of the motor 100. In other embodiments, the magnetic tunnel 104 may be the stator or the primary of the motor 100.

As illustrated in Figs. 4A and 4B, the magnetic tunnel 104 comprises a plurality of magnetic tunnel segments arranged longitudinally along the axis 101. In the embodiment illustrated in Fig. 4A, there are eight magnetic tunnel segments. In other embodiments, there may be any number of tunnel segments. The scope of this invention specifically includes and contemplates multiple tunnel segments having an opposite magnetic polarity direction to the adjacent magnetic tunnel segments. For simplicity and illustrative purposes, an eight segment magnetic tunnel 104 is described herein. However, this design choice is in no way meant to limit the choice or number of tunnel segments which may be required for any particular application. The actual number of magnetic tunnel segments selected for any given application may based on engineering design parameters and the particular performance characteristics for an individual application.

In Fig. 4A, a first plurality of tunnel segments 120a-120d have their side magnets orientated such that their south magnet poles are facing the viewer (conceptually represented for the purposes of this discloser with an "S" on the face of the magnet). A second plurality of tunnel segments 122a- 122d have their side magnets orientated such that their north poles are facing the viewer (conceptually represented for the purposes of this discloser with a "N" on the face of the magnet).

The magnetic tunnel 104 thus comprises tunnel segments 120a-120d which are longitudinally inter-dispersed between the tunnel segments 122a-122d. As will be explained below, each tunnel segment (e.g., tunnel segment 120a) is positioned adjacent to another tunnel segment (e.g. tunnel segment 122a) where the magnets forming the adjacent magnetic tunnel have their magnetic poles orientated or positioned in an opposite direction relative to the magnetic pole orientation of the adjacent magnetic tunnel.

In the illustrated embodiment, each of the magnetic tunnel segments 120a-120d are formed by four individual plate magnets (or a plurality of strip magnets positioned to form a plate magnet). Fig. 4C is a conceptual section view through a tunnel segment, such as tunnel segment 120a. In the illustrated embodiment, the tunnel segment 120a comprises a top or upper magnet 124, a lower or bottom magnet 126, a first side magnet 128, and a second side magnet 130. In this embodiment, the upper magnet 124 is positioned and configured such that its north pole is on the exterior face of the magnet (represented by the letter "N" in Fig. 4C). Consequently, its south pole faces the interior 132 of the tunnel (represented by the letter "S" in Fig. 4C). The first side magnet 128 is also positioned and configured such that its north pole is on the exterior face of the magnet and its south pole faces the interior 132 of the tunnel 120a. In contrast, the lower magnet 126 is positioned and configured such that its south pole is on the exterior face of the magnet and its north pole faces the interior 132 of the tunnel 120a. Similarly, the second side magnet 130 is positioned and configured such that its south pole is on the exterior face of the magnet and its north pole faces the interior 132 of the tunnel 120a.

The magnetic tunnel segments 122a-122d are also formed by four individual plate magnets (or a plurality of strip magnets positioned to form a plate magnet). Fig. 4D is a conceptual section view through an adjacent tunnel segment, such as tunnel segment 122a. The tunnel segment 122a is similar to the tunnel segment 120a except that the like magnetic poles of the magnets forming the tunnel segment 122a are orientated in an opposite direction from the like poles of magnets forming the tunnel segment 120a. To illustrate, the tunnel segment 122a comprises a top or upper magnet 134, a lower or bottom magnet 136, a first side magnet 138, and a second side magnet 140. In this embodiment, the upper magnet 134 is positioned and configured such that its south pole is on the exterior face of the magnet (represented by the letter "S" in Fig. 4D). Consequently, its north pole faces towards the interior 142 of the tunnel (represented by the letter "N" in Fig. 4D). The first side magnet 138 is also positioned and configured such that its south pole is on the exterior face of the magnet and its north pole faces the interior 142 of the tunnel 122a. In contrast, the lower magnet 136 is positioned and configured such that its north pole is on the exterior face of the magnet and its south pole faces the interior 142 of the tunnel 122a. Similarly, the second side magnet 140 is positioned and configured such that its north pole is on the exterior face of the magnet and its south pole faces the interior 142 of the tunnel 122a.

In certain embodiments, the magnets forming the magnetic tunnel 104 (or any magnetic tunnel segment, such as the magnetic tunnel segment 120a and 122a discussed above) may be made of out any suitable magnetic material, such as: neodymium, Alnico alloys, ceramic permanent magnets, or electromagnets. The exact number of magnets or electromagnets will be dependent on the required magnetic field strength or mechanical configuration. The illustrated embodiment is only one way of arranging the magnets, based on certain commercially available magnets. Other arrangements are possible, especially if magnets are manufactured for this specific purpose.

In the illustrated embodiment of Figs. 4C, there are slots between the magnetic walls, such as slot 144 between the magnetic wall 128 and the magnetic wall 124. The individual magnets in the magnetic walls 124, 126, 128, and 130 all have their magnetic poles orientated towards or away from an interior 132 of the magnetic tunnel segment 120a to form a "closed" magnetic tunnel. The term "closed magnetic tunnel" as used in this disclosure refers to using a arrangement of the magnets forming the tunnel segment 120 that that "forces" or "bends" the flux forces from one side of the tunnel to the other without first letting the forces escape through a slot or other opening. Thus, if there are slots between the magnetic walls (or in the walls), the slot widths are limited to keep flux forces from exiting through the slots. In other embodiments, additional magnets may be inserted into the slots to keep the flux forces channeled to a predetermined direction.

Fig. 5 A is an isometric view of the magnetic tunnel segment 120a having a portion of the coil structure 118 positioned within the interior of the segment. The top magnetic wall 124 is labeled with an "N" on its exterior face which means that the interior surface (not shown) contains its south pole. An arrow 150 pointing towards the center of the coil structure 118 represents the direction of the flux forces generated from the south poles (interior face) of the magnet(s) forming the top magnetic wall 124. Similarly, the exterior of the first side wall 128 is labeled with an "N" on its exterior surface which means that the interior surface (not shown) contains its south pole. Thus, an arrow 152 pointing towards the coil structure 118 represents the direction of the flux forces generated from the south poles of the magnet(s) forming the first side magnetic wall 128. In contrast, an arrow 154 pointing towards the coil structure 118 from the lower wall 126 represents the direction of the flux forces generated from the north poles of the magnet(s) forming the lower wall. Similarly, an arrow 156 pointing towards the coil structure 118 from the second side wall 130 represents the direction of the flux forces generated from the north poles of the magnet(s) forming the second side wall.

Fig. 5B is an isometric view of the magnetic tunnel segment 120a but with a coil winding 112a positioned around the core portion of the coil structure 118. When the motor/generator 100 is in motor mode, current from an external source (not shown) is applied to the coil windings, such as the coil winding 112a. When the motor/generator 100 is in generator mode, an applied force from an external source (not shown) causes relative movement between the coil structure 118 and the magnetic tunnel segment 120a, which in turn produces a current within the coil winding 112a.

In the illustrated embodiment, the current flows in a counterclockwise manner as illustrated by the arrow 160. Thus, arrow 160 represents the direction of current flow in an upper portion of the coil 112a - which flows in a right-to-left manner. The current then flows in a downwardly direction as illustrated by the arrow 162 when the current is in a side portion of the coil 112a adjacent to the first side wall 128. Then the current flows in a left-to-right direction as illustrated by arrow 164 when the current is in a lower portion of the coil 112a adjacent to the lower magnetic wall 126. Finally, the current flows in an upwardly manner as illustrated by the arrow 166 when the current is in a side portion of the coil 112a adjacent to the magnetic wall 130.

Fig. 5C is an isometric view of the magnetic segment 120a with a coil 112a positioned around the core 110 portion of the coil structure 118 and the current flowing through the coil as explained above in reference to Fig. 5B. In "motor mode" when the magnets forming the top magnetic wall 124 generate a flux in the direction of the arrow 150 and the applied current in the coil 112a flows in a right-to-left direction as represented by the arrow 160, an electromotive force will be generated in the direction of the arrow 170. When the magnets forming the wall 128 generate a flux in the direction of the arrow 152 and the applied current in the coil 112a flows in a downward direction as illustrated by the arrow 162, an electromotive force will be generated in the direction of the arrow 172. Simultaneously, the magnets forming the lower wall 126 generate a flux in the direction of the arrow 154 and the applied current in the coil 112a flows in a right-to-left direction as represented by the arrow 164, an electromotive force will be generated in the direction of the arrow 174. The magnets forming the second side magnetic wall 130 generate a flux in the direction of the arrow 156 and the applied current in the coil 112a flows in an upward direction as represented by the arrow 166, an electromotive force will be generated in the direction of the arrow 176. Thus, the electromotive force represented by the arrows 170, 172, 174, and 176 will cause relative movement between the coil structure 118 and the magnetic segment 112a. An adjacent magnetic segment, for instance 122a has its magnetic poles configured in an opposite direction. So, for the adjacent magnetic segment 122a to contribute to the overall electromagnet force, the current direction in the coils contained within the adjacent magnetic segment 122a are reversed so that the direction of its electromagnetic force is in the same direction, and thus contributes to the overall electromotive force produced by the motor.

In "generator mode" when the magnets forming the top magnetic wall 124 generate a flux in the direction of the arrow 150 and relative movement is caused by an applied force in the direction of the arrow 170, a generated current will be produced in the coil 112a flowing in a right-to-left direction as represented by the arrow 160. When the magnets forming the wall 128 generate a flux in the direction of the arrow 152 and relative movement is caused by an applied force in the direction of the arrow 172, a generated current will be produced in the coil 112a flowing in a downward direction as illustrated by the arrow 162. Simultaneously, the magnets forming the lower wall 126 generate a flux in the direction of the arrow 154 and relative movement is caused by an applied force in the direction of the arrow 174, a generated current in the coil 112a flowing in a right-to-left direction will be produced as represented by the arrow 164. The magnets forming the second side magnetic wall 130 generate a flux in the direction of the arrow 156 and relative movement is caused by an applied force in the direction of the arrow 176, a generated current in the coil 112a will be produced flowing in an upward direction as represented by the arrow 166. Thus, applied the applied force represented by the arrows 170, 172, 174, and 176 will cause relative movement between the coil structure 118 and the magnetic segment 120a, which in turn will cause a generated current in the coil winding 112a.

An adjacent magnetic segment, for instance the magnetic segment 122a has its magnetic poles configured in an opposite direction. So, when the same applied force causes relative movement between the coil structure 118 and the magnet segment 122a, the direction of the generated current produced the coil windings within the magnetic segment 122a will be opposite of the generated current produced by the coil windings within the magnet segment 120a.

In conventional configurations, the opposing poles of the magnets are usually aligned longitudinally. Thus, the magnetic flux lines will "hug" or closely follow the surface of the magnets. So, when using conventional power generating/utilization equipment, the clearances must usually be extremely tight in order to be able to act on these lines of force. By aligning like magnetic poles perpendicular or lateral to the coil structure 118 the magnetic flux forces flow from the surface of the magnets across the coil structure. This configuration allows for greater tolerances between coils and magnetic surfaces. One of the advantages of this configuration over conventional motors is that the end turns (in this case the radial section of the coils) are part of the "active section" of the invention. In conventional motors, the axial length of the copper conductor is the section that produces power. The end turns are a penalty, adding weight and losses, but not producing power because the end region fields are not effectively linking the end windings. However, as can be seen, the entire coil winding is effectively producing torque due to the side wall or axial magnets which are axially magnetized. Therefore, essentially the entire conductor of the coils is active producing a greater force.

The windings of each coil 112 are generally configured such that they remain transverse or perpendicular to the direction of the relative movement of the magnets comprising the coil structure 118 and parallel with the longitudinal axis 101. In other words, the coil windings 112 are positioned such that their sides are parallel with the longitudinal axis and their ends are perpendicular to the longitudinal axis. The windings are also transverse with respect to the magnetic flux produced by the individual magnets of the rotor at their interior face as described above. Consequently, the entire coil winding or windings may be used to generate movement (in motor mode) or voltage (in generator mode).

Surrounding the coils with magnets as described above creates more flux density and the forces are now all in the direction of motion which may create more force, minimize vibration, and minimize noise - as compared to conventional motors where forces may try to pull the coil downwards or push it upwards (depending on the polarity), not in the direction of motion.

In order maintain the generated movement and/or power the individual coils 112 in the coil structure may be selectively energized or activated by way of a switching or controller (not shown). The individual coils 112 in the coil assembly 106 may be electrically, physically, and communicatively coupled to switching or controller which selectively and operatively provides electrical current to the individual coils in a conventional manner.

For instance, the controller may cause current to flow within the individual coil as indicated in Fig. 5B when the individual coil is within a magnetic tunnel segment with a NNSS magnetic pole configuration as illustrated in Fig. 5B. On the other hand when the same individual coil moves into an adjacent magnetic tunnel segment with a SSNN magnetic pole configuration, the controller causes the current within the individual coil to flow in a direction opposite to that shown in Fig. 5B so that the generated magnetic force is in the same direction as illustrated by the arrows 170, 172, 174, and 176of Fig. 5C.

In multi-phase embodiments, the controller can apply forward current, reverse current, or no current. In operation, the controller applies current to the phases in a sequence that continuously imparts a force to move the magnetic tunnel in a desired direction (relative to the coil assembly) in motor mode. In certain embodiments, the controller can decode the rotor position from signals from position sensors or can infer the rotor position based on current drawn by each phase.

Force and continuous power, therefore, are greatly increased. Furthermore, force density, power density by volume, and power density by weight are also increased when compared to conventional electric motors.

As explained above, the configuration of the coils reduce or eliminate copper "end- windings" (windings outside the active zone), which may reduce heat, and in turn increases efficiency, and also minimizes the areas in need of cooling.

The abstract of the disclosure is provided for the sole reason of complying with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Any advantages and benefits described may not apply to all embodiments of the invention.

For the U.S. application, when the word "means" is recited in a claim element, Applicant intends for the claim element to fall under 35 USC 112. Often a label of one or more words precedes the word "means". The word or words preceding the word "means" is a label intended to ease referencing of claims elements and is not intended to convey a structural limitation. Such means-plus-function claims are intended to cover not only the structures described herein for performing the function and their structural equivalents, but also equivalent structures. Claims that do not use the word means are not intended to fall under 35 USC 112.

The foregoing description of the embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many combinations, modifications and variations are possible in light of the above teaching. For instance, in certain embodiments, each of the above described components and features may be individually or sequentially combined with other components or features and still be within the scope of the present invention. Undescribed embodiments which have interchanged components are still within the scope of the present invention. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims.

Claims

CLAIMS:

1. A linear motor/generator comprising:

a magnetic tunnel comprising a plurality of magnetic tunnel segments linearly arranged along a longitudinal axis forming a linear path, comprising:

a first magnetic tunnel segment comprising:

a top magnetic wall having a magnetic pole orientation that points generally towards an interior of the tunnel segment;

a lower magnetic wall having a magnetic pole orientation that points generally towards the interior of the tunnel segment;

a first magnetic side wall having a magnetic pole orientation that points generally towards the interior of the tunnel segment;

a second magnetic side wall having a magnetic pole orientation that points generally towards the interior of the tunnel segment;

wherein like magnetic poles of the top magnetic wall and like magnetic poles of the first side wall are orientated in an opposite direction from the like poles of lower magnetic wall and the like magnetic poles of second side wall; a second magnetic tunnel segment positioned longitudinally adjacent to the first magnetic tunnel segment, the second magnetic tunnel segment having the magnetic poles of the magnetic walls comprising the second magnetic tunnel segment orientated in a direction opposite to the magnetic poles of the magnetic walls comprising the first magnetic tunnel segment;

a coil assembly positioned along the linear path adapted to move relative to the magnetic tunnel, the coil assembly comprising:

a center core;

a plurality of ribs longitudinally positioned along the center core and extending laterally from the core to form a plurality of slots;

wherein each rib in the plurality of ribs is coupled to a frame extending in the longitudinal direction from an exterior edge of the rib;

a plurality of coil windings wherein each coil winding in the plurality of winding is positioned within a slot of the plurality of slots.

2. The linear generator/motor of claim 1 wherein the center core material is selected from the group consisting of iron, magnetic steel, or laminated steel.

3. The linear generator/motor of claim 1 wherein the top magnetic wall, the lower magnetic wall, the first side wall and the second side wall may be formed from electromagnets.

4. The linear generator/motor of claim 1 wherein substantially all of the wire windings in an individual coil is substantially positioned within the magnetic field created by the respective magnetic tunnel segment.

5. The linear generator/motor of claim 1 wherein the magnetic field generated by the top magnetic wall and a current flowing within wire windings in an adjacent coil creates a linear force in a direction of relative movement between the magnetic tunnel and the coil assembly.

6. The linear generator/motor of claim 1, wherein the magnetic field generated by the lower magnetic wall and a current flowing within wire windings in an adjacent coil creates a linear force in a direction of relative movement between the magnetic tunnel and the coil assembly.

7. The linear generator/motor of claim 1 wherein the magnetic field generated by the first magnetic side wall and a current flowing within wire windings in an adjacent coil creates a linear force in a direction of relative movement between the magnetic tunnel and the coil assembly.

8. The linear generator/motor of claim 1 wherein the magnetic field generated by the second magnetic side wall and a current flowing within wire windings in an adjacent coil creates a linear force in a direction of relative movement between the magnetic tunnel and the coil assembly.

9. The linear generator/motor of claim 1 wherein a linear force is generated on all sides of individual coils in the plurality of coils.

10. The linear generator/motor of claim 1 comprising an additional pair of magnetic tunnel segments wherein the additional pair includes the first magnetic tunnel segment and the second magnetic tunnel segment.

11. The linear generator/motor of claim 10, comprising a second additional pair of magnetic tunnel segments wherein the additional pair includes the first magnetic tunnel segment and the second magnetic tunnel segment.

12. The linear generator/motor of claim 11, comprising a third additional pair of magnetic tunnel segments wherein the additional pair includes the first magnetic tunnel segment and the second magnetic tunnel segment.

13. A method of producing linear motion, the method characterized by:

forming a first area of magnetic concentration within a first interior cavity defined by an first outer magnetic wall having a first magnetic pole facing the interior cavity, a first inner magnetic wall having a second magnetic pole facing the interior cavity, a first magnetic side wall having a third magnetic pole facing the interior cavity, and a first opposing magnetic side wall having a fourth magnetic pole facing the interior cavity, wherein the first and third magnetic poles are of opposite polarities from the second and fourth magnetic poles;

positioning a coil within the first interior cavity; and

applying a current in a first direction to cause the coil to move relative to the first interior cavity.

14. The method of producing linear motion of claim 13 further comprising:

forming a second area of magnetic concentration within a second interior cavity positioned linearly adjacent to the first interior cavity defined by an second outer magnetic wall having a fifth magnetic pole facing the interior cavity, a second inner magnetic wall having a sixth magnetic pole facing the interior cavity, a second magnetic side wall having a seventh magnetic pole facing the interior cavity, and a second opposing magnetic side wall having a eighth magnetic pole facing the interior cavity, wherein the fifth and seventh magnetic poles are of opposite polarities from the sixth and eight magnetic poles;

applying a current in a first direction to the coil to cause the coil to move to the second interior cavity; and

applying a current in a second direction to the coil when the coil is within the second interior cavity to move the coil out of the second interior cavity.

15. A method of producing electric current from a linear generator, the method characterized by:

moving a coil within the first interior cavity; and

extracting from the coil a current having a first direction as the coil moves through the first interior cavity.

16. The method of producing electrical current of claim 15 further comprising:

forming a second area of magnetic concentration within a second interior cavity defined by an second outer magnetic wall having a fifth magnetic pole facing the interior cavity, a second inner magnetic wall having a sixth magnetic pole facing the interior cavity, a second magnetic side wall having a seventh magnetic pole facing the interior cavity, and a second opposing magnetic side wall having a eighth magnetic pole facing the interior cavity, wherein the fifth and seventh magnetic poles are of opposite polarities from the sixth and eight magnetic poles, wherein the first through fourth magnetic poles are of an opposite polarity than the fifth through eight magnetic poles;

moving the coil within the second interior cavity; and

extracting from the coil a current having a second direction when the coil moves through the second interior cavity.