Variable torque dynamoelectric machine with adjustable halbach magnet array

Abstract

To provide an electric machine with variable torque generation having an adjustable Halbach array configuration.SOLUTION: The electric machine includes a magnet assembly for generating a magnetic field. The magnet assembly includes a plurality of fixed magnets disposed in a ring arrangement such that fixed magnets having a north pole adapted to face toward the rotor or stator are alternated with fixed magnets having a south pole adapted to face toward the rotor or stator, a plurality of rotatable magnets disposed in respective slots formed between two adjacent fixed magnets, and a drive assembly for turning the rotatable magnets in the slots, the drive assembly being configured to turn the rotatable magnets between a first position in which the magnetic field at the rotor or stator is enhanced and a second position in which the magnetic field at the rotor or stator is cancelled.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application was filed on March 2, 2020, and relates to a "Variable Torque This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62 / 984,270, filed September 11, 2020, entitled "Cascade Mosfet Design for Variable Torque Generator / Motor Gear Switching." This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 62 / 077,243, filed September 11, 2020, entitled "Cascade Mosfet Design for Variable Torque Generator / Motor Gear Switching." Co-pending non-provisional application No. XX / XXX,XXX, filed March 2, 2021, entitled "Cascade Mosfet Design for Variable Torque Generator / Motor Gear Switching," is incorporated herein by reference in its entirety. Furthermore, co-pending non-provisional application No. XX / XXX,XXX, entitled "Cooling System for Variable Torque Generation Electric Machine," filed March 2, 2021, is incorporated by reference herein in its entirety. [Background technology]

[0002]

[0002] An electric machine is a device that uses electromagnetic forces to convert electrical energy into mechanical energy or mechanical energy into electrical energy. Commonly known electric machines include electric generators and electric motors.

[0003]

[0003] Electric generators convert mechanical energy into electrical energy for use in external circuits such as power grids, electrical systems in vehicles, etc. Most generators use a source of motive power in the form of a rotational force (torque), such as the rotation of a shaft. The rotational force causes an electric current to be generated in one or more windings of wire by the interaction between the wire windings and a magnetic field created by magnets in the generator. Common sources of motive power include steam turbines, gas turbines, hydroelectric turbines, internal combustion engines, and the like, which have a constant torque and a continuous rotational speed, expressed in revolutions per minute (RPM).

[0004]

[0004] An electric motor is mechanically identical to an electric generator, but operates in reverse. An electric motor converts electrical energy into mechanical energy through the interaction of a magnetic field created by magnets within the motor and an electric current passing through one or more wire windings to generate motive power (i.e., rotational force or torque) in the form of rotation of the motor's shaft. This rotational force (torque) is then used to propel some external mechanism. Electric motors are generally designed to provide continuous rotation and constant torque. In certain applications, such as in vehicles using regenerative braking with a traction motor, an electric motor can be used in reverse as a generator to recover energy that would otherwise be lost as heat and friction.

[0005]

[0005] Increasingly, electric generators used in renewable energy technologies must operate at widely varying rotational speeds (RPM) and torques because the power sources used are variable, irregular, and often unpredictable. Similarly, electric motors used by environmentally friendly or green technologies must be capable of producing a range of rotational speeds (RPM) and torques. However, conventional electric While generators and motors often demonstrate efficiencies ranging from ninety to ninety-eight percent (90%-98%) when operated near their rated rotational speed (RPM) and torque, the efficiency of these same generators and motors decreases dramatically, often as low as thirty to sixty percent (30%-60%), when they are operated outside of their rated rotational speed (RPM) and / or torque.

[0006] The detailed description will now be described with reference to the accompanying drawings. The use of the same reference numbers in different instances in the description and drawings may refer to similar or identical items. Additionally, it will be appreciated by those skilled in the art that the concepts disclosed herein may be applied to various types of electric machines, including, but not limited to, electric motors, electric generators, and / or electromechanical transmission systems. Thus, throughout this disclosure and in the claims that follow, the term electric machine will be used generally to describe any electromechanical device capable of employing the concepts described herein, and it will be appreciated that, unless otherwise stated, the term electric machine may refer to an electric motor, an electric generator, an electromechanical transmission system, combinations thereof (e.g., an electric machine may include a motor / generator suitable for use in a hybrid vehicle employing regenerative braking), etc. [Brief explanation of the drawings]

[0007] [Figure 1]

[0007] FIG. 1 is a side view illustrating an electric machine according to an example embodiment of the present disclosure. [Figure 2]

[0008] 2 is an illustrative perspective view of the electric machine shown in FIG. 1 according to an example embodiment of the present disclosure. [Figure 3]

[0009] 2 is a cross-sectional perspective view of the electric machine shown in FIG. 1, including a housing, a rotor assembly, a stator assembly, and a main shaft, according to an example embodiment of the present disclosure. FIG. [Figure 4]

[0010] FIG. 4 illustrates a further cross-sectional perspective view of the electric machine shown in FIG. 3, showing a rotor assembly having a Halbach configuration, according to an example embodiment of the present disclosure. [Figure 5]

[0011] 3A-3C illustrate different cross-sectional perspective views of the electric machine shown in FIG. 2, parallel to the main axis, showing the stator assembly and rotor assembly, according to example embodiments of the present disclosure. [Figure 6]

[0012] 6 is a side view illustrating a rotor assembly of the electric machine in FIG. 5 having two sets of rotatable magnets arranged in a Halbach array, according to an example embodiment of the present disclosure. [Figure 7]

[0013] 7 is a perspective view illustrating a rotor assembly of the electric machine of FIG. 6 arranged in a Halbach array according to an example embodiment of the present disclosure. [Figure 8]

[0014] FIG. 7 is a perspective view of a fixed magnet of the Halbach array of the rotor shown in FIG. 6 according to an example embodiment of the present disclosure. [Figure 9]

[0015] FIG. 7 is a front view of a fixed magnet of the Halbach array of the rotor shown in FIG. 6, according to an example embodiment of the present disclosure. [Figure 10]

[0016] FIG. 7 is a perspective view of the rotor assembly shown in FIG. 6, showing a magnet assembly and a driver assembly for rotating rotatable magnets in the magnet assembly, according to an example embodiment of the present disclosure. [Figure 11]

[0017] FIG. 11 is a perspective view of the rotor assembly shown in FIG. 10, further showing a magnet assembly and a driver assembly, according to an example embodiment of the present disclosure. [Figure 12]

[0018] 3 is a perspective view of a different embodiment of the rotor assembly shown in FIG. 2 having a driver assembly and a magnet securing lid around the periphery of the magnet assembly according to an example embodiment of the present disclosure. [Figure 13]

[0019] FIG. 10 is a perspective view of another embodiment of an electric machine according to an example embodiment of the present disclosure. [Figure 14]

[0020] FIG. 14 is a perspective view of the mounting bracket shown in FIG. 13 with a torque sensor according to an example embodiment of the present disclosure. [Figure 15]

[0021] 14 is a cross-sectional perspective view of the electric machine shown in FIG. 13, including a housing, a rotor assembly, a stator assembly, and a main shaft, according to an example embodiment of the present disclosure. FIG. [Figure 16]

[0022] FIG. 14 is a perspective view of an end cap of the shaft shown in FIG. 13 according to an example embodiment of the present disclosure. [Figure 17]

[0023] 16 is a side view illustrating a rotor assembly of the electric machine in FIG. 15 having one set of rotatable magnets arranged in a Halbach array, according to an example embodiment of the present disclosure. [Figure 18]

[0024] FIG. 16 is a perspective view of the rotor assembly shown in FIG. 15, showing the main shaft, the magnet assembly, and a driver assembly for rotating the rotatable magnets in the magnet assembly, according to an example embodiment of the present disclosure. [Figure 19]

[0025] FIG. 19 is a perspective view of a fixed magnet of the Halbach array of the rotor shown in FIG. 18 according to an example embodiment of the present disclosure. [Figure 20]

[0026] FIG. 19 is a side view of a fixed magnet of the Halbach array of the rotor shown in FIG. 18, according to an example embodiment of the present disclosure. [Figure 21]

[0027] FIG. 16 is a perspective view of the rotor assembly shown in FIG. 15, showing a magnet assembly and a driver assembly for rotating rotatable magnets in the magnet assembly, according to an example embodiment of the present disclosure. [Figure 22]

[0028] FIG. 16 is a perspective view of the rotor assembly shown in FIG. 15, showing magnet assemblies configured in a Halbach array, according to an example embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] Overview

[0029] Although the present subject matter has been described in language specific to structural features and / or process acts, it should be understood that the present subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

[0009]

[0030] The detailed description will be described with reference to the accompanying drawings. The use of the same reference numbers in different instances in the description and drawings may refer to similar or identical items. Additionally, it will be appreciated by those skilled in the art that the concepts disclosed herein may be applied to various types of electric machines, including, but not limited to, electric motors, electric generators, and / or electromechanical transmission systems. Thus, throughout this disclosure and in the claims that follow, the term electric machine will be used generally to describe any electromechanical device capable of employing the concepts described herein, and it will be appreciated that, unless otherwise stated, the term electric machine may refer to an electric motor, an electric generator, an electromechanical transmission system, combinations thereof (e.g., an electric machine may include a motor / generator suitable for use in a hybrid vehicle using regenerative braking, a generator suitable for a wind turbine, etc.), etc.

[0010]

[0031] Motors and generators are designed for operation at a specific rotatable speed and torque, with a very narrow range of optimum efficiency; high torque requirements in a motor or generator call for more powerful permanent magnets that create a large back electromotive force (EMF) that is overcome by high voltage and current. When the rotatable speed and torque are constant, the motor or generator can be designed for optimum efficiency. Often, this efficiency can be well above ninety percent (90%). Thus, in the design and manufacture of such motors and generators, the stator core, core windings, and permanent magnets are all designed for optimum or threshold efficiency. The motor or generator is typically configured with a fixed magnet back-emf that must be overcome when the speed and torque requirements are less than the maximums for which it was designed, and the stator wiring must still be adequate and properly sized when the speed and torque requirements are greater than the maximums for which it was designed. When these fixed magnet back-emf and stator wiring are not, the overall efficiency of the motor or generator drops dramatically—in many cases to as low as twenty percent (20%)—for electric or hybrid vehicles, wind or hydro generators, and the like.

[0011]

[0032] The present disclosure is directed to variable torque generating (VTG) electric motors, electric generators, and / or transmission systems capable of operating with high efficiency over a wide voltage and amperage operating range and / or under highly variable torque and rotatable speed (RPM) conditions. Electric motors according to the present disclosure are well suited for use in technologies where motors produce variable torque and / or rotatable speed (RPM). Similarly, electric generators according to the present disclosure are well suited for use in technologies where variable torque and rotatable speed (RPM) conditions are common, such as where variable environmental conditions are frequently encountered, such as uneven wind speeds, erratic ocean wave motion, variable braking energy in hybrid vehicles, etc. Example technologies may include technologies using renewable energy sources, including, for example, wind power, hydroelectric power, electric or hybrid vehicles, etc.

[0012]

[0033] As previously discussed, the rotor magnetic field in permanent magnet electric motors and generators is fixed, not adjustable. It is the alternating flow of magnetic flux between the rotor's permanent magnets and the stator core, and the alternating flow of electricity in the stator core's wires, that determines how a permanent magnet motor or generator will operate. If there is a small amount of magnetic flux flowing between the rotor magnets and the stator core, it is as if the motor's or generator's rotor were fitted with smaller or lower strength permanent magnets. If a large amount of magnetic flux flows between the rotor magnets and the stator core, the opposite is true: the strength of the permanent magnets in the motor's or generator's rotor is higher. When small permanent magnets are used in the motor's rotor, the wire in the stator core coils is sized by the required number of turns to produce optimal (or near-optimal) magnetic flux flow between the rotor and stator, and a magnetic field in the stator teeth (or core) that will efficiently react to the rotor magnet's magnetic field to produce optimal (or near-optimal) torque or rpm. In the case of a generator, the wire is sized by the required number of turns to efficiently accommodate the electricity generated by the alternating magnetic flux induced in the stator core by the permanent magnets on the rotating rotor. Motors and generators can have different numbers of wire windings even if their respective permanent magnets are the same size. The number of wire and turns in a large permanent magnet rotor differs from the number of wire and turns in a small permanent magnet rotor, and the output sizes of the two rotors are significantly different.

[0013]

[0034] The techniques described herein involve the use of a rotor in an electric machine, such as a motor, generator, transmission, or the like, by one or more of: varying the magnetic field induced in the stator by switching a plurality of untwisted parallel coil wires in the stator between being connected all in series, all in parallel, or a combination thereof; and correspondingly adjusting (e.g., varying, adjusting, or focusing) the magnetic field of a permanent magnet acting on the stator using an adjustable Halbach magnet arrangement in the rotor. The output "size" can be dynamically changed. An adjustable Halbach magnet arrangement consists of interspersed fixed and rotatable magnets that can be rotated to adjust the magnetic field strength of the magnet array. Additionally, as torque / RPM or current / voltage requirements change, the system can activate one stator or another in the rotor / stator assembly (in multiple electric machine units connected to a common computer processor) to change from parallel windings to series windings, or vice versa, with two (2), four (4), six (6), or more parallel three-phase untwisted coil winding assemblies. In this manner, the system can meet the torque / RPM or current / voltage requirements of the electric machine while improving (e.g., increasing, optimizing, or near-optimizing) the system's efficiency.

[0014]

[0035] The present disclosure provides systems and methods for adjusting the magnetic field of a permanent magnet rotor in an electric machine, such as an electric motor, generator, or transmission. The present disclosure does so by using an adjustable Halbach magnet array configuration to adjust (e.g., vary, adjust, and / or focus) the magnetic field acting on the stator core to meet the torque and speed (RPM) requirements of the electric machine at any given time. By reducing or increasing the magnetic field acting on the stator core, the technique reduces or increases the back EMF, respectively. For example, in the case where the electric machine is a motor, reducing or increasing the back EMF may result in the motor using a lower or higher voltage and current (power) to operate. In another example, if the electric machine is a generator, varying the back EMF of the magnetic field will vary the torque (e.g., wind speed) required to turn the generator. The present disclosure enables systems using electric machines to adjust back-EMF to meet varying conditions, allowing the electric machine to operate at greater efficiency over a much wider range of torque than previously possible. These capabilities allow the electric machine to control the strength of interaction of both the rotor and stator magnetic fields over a relatively uniform range of variable power requirements with high efficiency. The efficiency of any electric motor depends on the balance between the stator's electromagnetic field and the rotor's electromagnetic field interacting with the stator. An inverter / controller in the electric machine can adjust the voltage received from an electrical source, such as a battery or other electrical source, by adjusting the amount of current in the stator coil wires, within the capacity of the wires and voltage source. The electric machine can switch between different wiring combinations, each with a different resistance. The different resistances of the wiring combinations create different ranges of amperage turns as the inverter / controller in the computer processor increases the voltage in each wiring configuration from low to high.Different wiring configurations are then configured, combined, and organized with voltage adjustments so that as the computer processor switches the wiring from one configuration to the next, correspondingly changing the number of turns in the stator coils and the resulting magnetic field strength, the overall range of current flow in the stator coils can be adjusted uniformly (increased or decreased) over a greatly extended range. Due to the ability of electric machines to focus or control the magnetic field of the rotor magnets interacting with the stator coils over a much larger range, from low to high, by movement of one or more rotors relative to the stator, the computer processor can be configured to adjust the rotor's magnetic field relative to the stator, a function of the number of turns in the stator coils, such that the rotor is adjusted to provide optimal efficiency or balance between the magnetic fields of the stator coils and the rotor permanent magnets.

[0015]

[0036] Varying the wiring and number of turns to modify the flux and electricity flowing in the stator core coil wires is not as easy to adjust or vary as changing the flux flowing from the rotor permanent magnets. This allows for multi-phase stator wiring in a center tap, or delta configuration, with the ability to switch and connect multiple wires in all series, all parallel, and combinations of parallel and series configurations. This can be accomplished by separating the three legs and providing multiple untwisted parallel wires (and in some cases, with different size wires) in the core winding for each phase leg. In some implementations, one or more wires can be disconnected to create additional configurations (e.g., from a six-wire system to a four-wire system, or the like). In some implementations, the phase windings can also be switched from a star or wye configuration to a delta (e.g., triangle) configuration. In some implementations, the system can provide two separate polyphase wiring configurations with separate controllers for the same stator, and in some implementations, in either separate polyphase configuration, the coils in each phase leg (including multiple wires therein) can be switched (e.g., using electronic switches) to be connected in series, parallel, or a combination thereof in either a star (wye) or delta configuration.

[0016]

[0037] In embodiments, the electric machine may further be provided by linking together multiple modular electromechanical units (e.g., each having its own stator and rotor) to vary the overall system output. For example, the electromechanical units may be linked together under common control from a central processor, where they may operate together for increased power or at least one may operate while another is neutral. The electromechanical units may further be configured to transition between different series, parallel, or combinatorial (i.e., series and parallel) wiring and switching combinations to provide smooth transitions between various combinations. The electromechanical units may further be transitioned between delta or star phase configurations by series / parallel switching of multiple wires in each phase.

[0017]

[0038] In embodiments of the present disclosure, any single electric machine unit may have any or all of the multiple wiring and switching combinations described herein, including switching between delta and wye configurations, multiple wire windings in sets of two or more wires connected in series or parallel, or in sets of two or more wires connected in series and parallel to each other, and if the electric machine is multi-polar, the individual coils of the phase windings may be connected in series or parallel, or in sets of two or more coils connected in series and parallel to each other, resulting in a wide range of voltage / current magnitudes and torque / speed ratios in a single electric machine that can be electronically reconfigured to meet widely varying conditions. This feature, combined with the ability to electronically shift and focus the rotor field on the stator core, results in the ability by a computer system processor to select and rapidly change stator winding configurations to meet widely variable speed and torque requirements that can be imposed on the electric machine at optimal (or near-optimal, or otherwise selected) energy efficiency.

[0018]

[0039] The electric machine of the present disclosure may further include a cooling system that uses series and parallel switching to gradually reduce the resistance of the stator coils to increase the amount of current in the coils without incurring significant losses. Cooling the wires allows them to carry as much as five times their rated capacity. In comparison to a conventional motor or generator with a single conductor per phase, a cooled conventional electric machine may have its mechanical power increased by as much as five times due to the cooling; in this case, the electric machine may have its mechanical power increased by as much as 30 times.

[0019]

[0040] The cooling system of the present disclosure includes an enclosed stator core, a coil fluid cavity with a circulating cooling fluid, and a cooling system using water or other suitable fluid to reduce the temperature of the cooling fluid circulated within the fluid cavity. The cooling device may include piping for circulating a fluid, and a thermoelectric element, such as a Peltier element, in contact with the cooling fluid.

[0020] Detailed Description of Example Embodiments

[0041] 1-21 illustrate an electric machine having a rotor using an adjustable Halbach array configuration according to the present disclosure. The Halbach array configuration allows the magnetic flux of permanent magnets in the electric machine to be adjusted (e.g., varied, tuned, focused, etc.) to vary electrical induction in coils in controlled increments from maximum current and / or voltage to zero or near-zero current and / or voltage. The electric machine includes a housing, a stator, and at least one rotor. The at least one rotor includes a circular Halbach array of magnets, including fixed magnets having a somewhat hourglass shape or cross-section (e.g., an I-shaped cross-section) and rotatable magnets having a cylindrical (round) shape or cross-section, with the rotatable magnets positioned between slots between adjacent ones of the fixed magnets. The fixed magnets are mounted on the stator core around its periphery and positioned with adjacent north and south poles alternating and facing outward toward the stator. The rotatable magnets are diametrically magnetized. A minimal uniform gap is provided between the inner wall of the fixed magnet and the outer wall of the rotatable magnet. The inner wall of the fixed magnet may be coated with a friction-reducing coating, such as a Teflon™ or Delrin™ type material, or other polymer that reduces friction between surfaces.

[0021]

[0042] 1-5, an electric machine 100 is described in accordance with an embodiment of the present disclosure. As noted hereinabove, the term electric machine may refer to an electric motor, an electric generator, a transmission system, combinations thereof, and the like.

[0022]

[0043] As shown in Figures 3-5, the electric machine 100 includes a housing 102, a main shaft 104, a stator assembly 106, and a rotor assembly 108. The housing 102 includes a stator chamber 103. The main shaft 104 is disposed within the housing 102 and is rotatably connected to the housing 102, for example, by one or more bearings that support the shaft 104. The stator assembly 106 is further disposed within the housing 102. The stator assembly includes a stator core 110 that supports a plurality of windings 112. Figures 6 and 7 show the rotor assembly 108. The rotor assembly 108 is coupled to the main shaft 104 and configured to rotate relative to the stator assembly 106 to rotate the main shaft 104. The rotor assembly 108 includes a rotor core 114 , a first magnet assembly 116 , and a second magnet assembly 117 .

[0023]

[0044] 10 , the first magnet assembly 116 includes a first plurality of fixed magnets 118 and a first plurality of rotatable magnets 120 arranged in a first wheel arrangement 119. In the illustrated embodiment, the fixed magnets 118 have an overall somewhat hourglass shape or cross-section (e.g., an I-shaped cross-section). As shown, the I-shaped fixed magnets 118 have concavely curved inner sides such that slots 126 are formed between adjacent ones of the fixed magnets 118 near the periphery of the rotor assembly 108. Each of the fixed magnets 118 includes a north pole 122 and a south pole 124. Adjacent fixed magnets 118 are separated by respective ones of the slots 126. Each of the fixed magnets 118 is mounted to the rotor core 114 and oriented so that its respective north pole faces either outward toward the stator assembly 106 and away from the rotor core 114, or inward toward the rotor core 114 and away from the stator assembly 106, while its respective corresponding south pole faces in the opposite direction, i.e., inward toward the rotor core 114 and away from the stator assembly 106, or outward toward the stator assembly 106 and away from the rotor core 114. The differently oriented fixed magnets 118 are arranged in an alternating configuration near the rotor core 114 so that the fixed magnets 118 with their north poles facing the stator assembly 106 are positioned between the fixed magnets 118 with their south poles facing the stator assembly 106.

[0024]

[0045] Each of the plurality of rotatable magnets 120 is disposed in a respective slot 126 between two adjacent fixed magnets 118. In the illustrated embodiment, the rotatable magnets 120 include a generally cylindrical body having a first end 128 and a second end 130. The cylindrical body of each rotatable magnet 120 includes a first half-cylinder 132 and a second half-cylinder 134 that extend from the first end 128 to the second end 130 of the cylindrical body of the rotatable magnet 120. The first and second half-cylinders 132 and 134 correspond to the north pole of the rotatable magnet 120 and the south pole of the rotatable magnet 120, respectively. In embodiments, the rotatable magnet 120 may be a single piece magnet extending the length of the stator 106, as shown in FIG. 17, or may be comprised of multiple rotatable magnets joined together by a shaft 121, with the poles of the multiple rotatable magnets aligned in the same or different directions.

[0025]

[0046] The rotor assembly 108 further includes a first drive assembly 136 for rotating the rotatable magnet 120 in the slot 126 between the fixed magnets 118, causing the magnetic field generated by the magnet assembly to fluctuate. In the illustrated embodiment, the rotatable magnet 120 is attached to a shaft 121 that extends through the longitudinal center of the rotatable magnet 120 relative to the length of the rotor assembly 108 and sufficiently beyond the ends of the rotor assembly 108 to receive an axle gear 123 on at least one end of the shaft 121. In other embodiments, the shaft 121 may be replaced or supplemented by other gears, bearings, or bushings fixedly connected to the first and second ends 128, 130 of the rotatable magnet 120.

[0026]

[0047] The bearings or bushings connecting the shaft 121 to the rotatable magnet 120 may be mounted on non-magnetic plates on either end of the rotor assembly 108 or in intermittent sections along the length of the rotor. Other embodiments of the rotor assembly 108 may use a synthetic polymer, including but not limited to polytetrafluoroethylene (PTFE) or Teflon™, to coat the inner surface of the circular space between the first and second half-cylinders 132, 134 of the rotatable magnet 120 to minimize friction between the rotatable magnet 120 and the shaft 121.

[0027]

[0048] The driver assembly rotates the rotatable magnet in a first direction (e.g., clockwise) between a first position, shown in Figures 10 and 11, where the magnetic field in the rotor or stator is increased or enhanced, and a second position (not shown) where the magnetic field in the rotor or stator is canceled. Rotating the north pole 132 of the rotatable magnet 120 toward the center of the fixed magnet, where the north pole 122 of the fixed magnet faces outward, away from the rotor core 114, increases the magnetic field of the rotor assembly 108. In contrast, rotating the north pole 132 of the rotatable magnet 120 toward the center of the fixed magnet, where the south pole 124 of the fixed magnet faces outward, decreases the strength of the magnetic field to zero or near zero (e.g., zero or near zero gauss). The magnetic field of the rotor assembly 108 can be varied over a wide range of field strength (Gauss) output so that application requirements can be met in a more efficient manner compared to the prior art. The rotation of the rotatable magnets 120 can be reversed in up to 180 degree increments so that the respective north and south poles 132, 134 of the rotatable magnets 120 face the radial plane of the fixed magnet of the opposite polarity.

[0028]

[0049] 10 and 11 further illustrate a second magnet assembly 117 having a second plurality of fixed magnets 138 and a second plurality of rotatable magnets 142 arranged in a second wheel arrangement 140. In the illustrated embodiment, the fixed magnets 138 have a somewhat overall hourglass shape or cross-section (e.g., an I-shaped cross-section). As shown, the I-shaped fixed magnets 138 have concavely curved inner sides such that slots 126 are formed between the fixed magnets 138. Each of the fixed magnets 138 includes a north pole 122 and a south pole 124 and is separated by a respective one of the slots 126. Each of the fixed magnets 138 is mounted on the rotor core 114 and oriented so that its respective north pole faces either outward toward the stator assembly 106 and away from the rotor core 114, or inward toward the rotor core 114 and away from the stator assembly 106, while its respective south pole faces in the opposite direction, i.e., inward toward the rotor core 114 and away from the stator assembly 106, or outward toward the stator assembly 106 and away from the rotor core 114. A rotatable magnet 142 is disposed in a respective slot 126 between two adjacent fixed magnets 138. A rotatable magnet 142 includes a generally cylindrical body having a first end 128 and a second end 130. The cylindrical body of the rotatable magnet 142 includes a first half-cylinder 132 and a second half-cylinder 134 that extend from a first end to a second end of the cylindrical body of the rotatable magnet. The first and second half-cylinders 132 and 134 correspond to the north and south poles of the rotatable magnet, respectively.

[0029]

[0050] The second magnet assembly 117 further includes a second drive assembly 144 for rotating the second plurality of rotatable magnets 142 in the slots 126 between the second plurality of fixed magnets 138, allowing the magnetic field generated by the second magnet assembly 117 to vary. The second drive assembly 144 rotates the rotatable magnets 142 counterclockwise between a first position where the magnetic field is increased and a second position where the magnetic field in the rotor or stator is canceled. Rotating the north pole of the rotatable magnet 142 toward the central radial plane of the fixed north pole magnet 122, where the fixed north pole magnet 122 faces outward from the rotor core 114, increases the magnetic field of the electric machine 100. In contrast, rotating the north pole of the rotatable magnet 142 toward the central radial plane of the fixed south pole magnet 124, where the fixed south pole magnet 124 faces outward from the rotor core 114, reduces the strength of the magnetic field to near zero (e.g., near zero (0) Gauss), which allows the rotor assembly 108 to vary the magnetic field over a wide range of Gauss output. The rotation of the rotatable magnet 142 can be reversed in up to 180 degree increments so that the respective north and south poles of the round magnet face the radial plane of the fixed magnet of the opposite polarity.

[0030]

[0051] In this embodiment, the first magnet assembly 116 and the second magnet assembly 117 are adjacent to one another. The first magnet assembly and the second magnet assembly are arranged in an alternating order. A first plurality of fixed magnets 118 having a north pole 122 facing outward toward the stator assembly 106 is adjacent to a fixed magnet of the second plurality of fixed magnets 138 having a south pole 124 facing outward toward the stator assembly 106. Similarly, a fixed magnet of the first plurality of magnets 118 having a south pole 124 facing toward the stator assembly 106 is adjacent to a fixed magnet of the second plurality of fixed magnets 138 having a north pole 122 facing toward the stator assembly 106.

[0031]

[0052] 10 and 11 illustrate that a rotatable magnet from the first plurality of rotatable magnets 120 is coupled to a rotatable magnet from the second plurality of rotatable magnets 142 to form a multiple rotatable magnet assembly 146. The rotatable magnet assembly has a first side 132 and a second side 134. A rotatable magnet from the first plurality of rotatable magnets 120 is coupled to a magnetic north pole disposed on the first side 132 of the rotatable magnet assembly. and a south pole disposed at the second side 134 of the rotatable magnet assembly. The rotatable magnets from the second plurality of rotatable magnets 142 may have a south pole disposed at the first side 132 of the rotatable magnet assembly and a north pole disposed at the second side 134 of the respective magnet assembly. Every other rotatable magnet assembly may be positioned at a 180 degree rotational angle relative to an adjacent rotatable magnet assembly along the wheel arrangements 119 and 140 of the rotor assembly 108.

[0032]

[0053] In one embodiment, each of the first and second rotatable magnet assemblies 120 and 142 includes a drive assembly having a planetary gear 148. Each of the first and second drive assemblies 136 and 144 further includes a ring gear 150 engaged to a motive device 152 by a drive gear 154. The motive device 152 may be a stepper motor, a hydraulic piston, or any other radial or linear motion device known in the art. Different embodiments of the present invention may include two or more motive devices on each side of the rotor assembly. The ring gear 150 is connected to the planetary gears 148. As seen in FIG. 10 , the motive device 152 rotates a drive gear 154, which rotates the ring gear 150 to rotate the planetary gears 148. The planetary gears 148 enable each respective rotatable magnet assembly to rotate the plurality of rotatable magnets 120 and 146 in the slots 126 between the plurality of rotatable fixed magnets 118 and 138. In alternative embodiments, including but not limited to, the axle gears 123 meshing all round axle gears 123 together such that alternate rotatable magnets 120 on either side of the fixed magnet 118 rotate clockwise and counterclockwise in alternating order, the axle gears 123 may be rotated by other transmission means other than ring gears at the ends of the rotatable magnets 120.

[0033]

[0054] The main shaft 104 may be configured to support one or more motive devices 152. The motive devices 152 may be positioned parallel to the longitudinal axis of the main shaft 104, facing forward, and facing rearward, depending on the number of motive devices 152 used in different embodiments of the electric machine 100. The main shaft 104 may also support different electronic devices used to control the one or more motive devices, such as, but not limited to, a printed circuit board (PCB), a power converter, combinations thereof, etc. The main shaft 104 may also include a rotational position indicator, which may be located at an end of the main shaft 104.

[0034]

[0055] FIG. 13 shows a different embodiment of the housing 102 inside the mounting bracket 156. The mounting bracket 156 shown in FIG. 14 is rotatably connected to the main shaft 104 by means of bearings 158 on either side of the main shaft 104. This configuration allows the housing 102 to have free rotational movement relative to the mounting bracket 156. The shaft 104 includes an end cap 157 with a position sensor 159 and a wireless communication device. The position sensor 159 measures the RPM of the electric machine, and the wireless communication device communicates and sends commands to each of the motive devices 152. Another possible configuration for the mounting bracket 156 includes, but is not limited to, a fully enclosed shroud. This enclosed shroud mounting bracket (not shown) would protect the electric machine from environmental contaminants and weather conditions.

[0035]

[0056] 14, the mounting bracket 156 may include torque sensors, such as, but not limited to, two load cells 160 mounted on either side of the electric machine housing 102. The load cells 160 may measure tension or compression to determine the torque of the electric machine in either direction. This torque measurement may be used in addition to other measured parameters (e.g., rpm, etc.) to determine the power input or output of the electric machine 100.

[0036]

[0057] A second embodiment of the electric machine 100 is illustrated in Figures 13 through 22. In this second embodiment of the electric machine, the rotor 302 includes a single magnet assembly 304. Figures 19 and 20 show multiple fixed magnets 306. The I-shaped fixed magnets are arranged around the periphery of the rotor wheel and secured to conventional laminations 307. Each fixed magnet 306 includes alternating north and south poles facing radially outward from the central axis of the rotor 302 around the periphery of the rotor wheel. Multiple rotatable magnets 308 are located in slots 310 between the fixed magnets 306. The slots 310 may be coated with a friction-reducing coating, such as a Teflon™ or Delrin™-type material, or other polymer that reduces friction between surfaces.

[0037]

[0058] The rotatable magnets 308 on either side of the fixed magnet 306 are designed to rotate in opposite directions, preferably by approximately 180 degrees, but without limitation. The rotatable magnets 308 are rotated by means of sprockets 312 fixedly connected to the ends of the rotatable magnets. In addition to including the sprockets 312, the drive assembly 314 further includes two ring gears 316 and 318 and a motive device 320. Each of the ring gears 316 and 318 includes teeth on its outer periphery that rotate the sprockets 312 on every other rotatable magnet 308, respectively. In this embodiment, the first ring gear 316 rotates the first set of rotatable magnets clockwise, while the second ring gear 318 rotates the second set of rotatable magnets counterclockwise. Ring gears 316 and 318 are in turn rotatably connected to respective motive devices 320 by means of teeth around the inner periphery of each ring gear. Different embodiments can vary the direction of rotation for the first and second ring gears.

[0038]

[0059] Embodiments referred to in this disclosure may include magnetic metal laminations around the rotor core 322 as magnet securing caps 324 for securing multiple fixed magnets to the rotor wheel, as shown in FIG. 9 . The magnet securing caps 324 may be separated tangentially from each other by gaps 325 to focus the variable-strength magnetic field of the combined rotor assembly 108 radially outward toward the stator assembly 106. In different embodiments, the magnet securing caps may be positioned continuously between the north and south poles and not separated by gaps. The magnetic metal laminations may be magnetic iron but may be made from a different ferromagnetic material. The stator core material may be magnetic iron, another magnetic material, a non-magnetic material (e.g., aluminum, etc.), or any combination of magnetic and non-magnetic materials.

[0039]

[0060] The stator core material can be magnetic iron, another magnetic material, a non-magnetic material (e.g., aluminum, etc.), or any combination of magnetic and non-magnetic materials. Different embodiments of the present invention can include a metal jacket 326 around the multiple rotatable magnets. The jacket 326 can be made of stainless steel or other metal alloys.

[0040]

[0061] In other embodiments, electric machine 100 may include fixed magnets of different depths, shapes, and sizes. The fixed magnets in other embodiments may even be spaced apart at different distances from one another to mount rotatable magnets between them to produce the variable magnetic field and desired induction of electrical current in the stator coils. In other embodiments, the rotatable magnets may be cylindrical in shape, with a diameter related to the depth of the fixed magnets, which will produce the variable magnetic field and desired induction of electrical current in the stator coils.

[0041]

[0062] In another embodiment, the electric machine 100 includes a rotor core that supports multiple windings. The rotor assembly may include a rotor disposed within a housing having a main shaft. The rotor assembly may be coupled to a main shaft and configured to rotate relative to a stator assembly. The stator assembly may include a stator core having at least one magnet assembly, the at least one magnet assembly having an adjustable Halbach array configuration according to the present disclosure.

[0042]

[0063] It should be understood that the term "stator" is used herein to describe an element of an electric machine in which coils of wire are located and into which electric current is induced by the magnetic field of a permanent magnet or is pumped by other sources to produce a magnetic field EMF for interacting with the magnetic field of the permanent magnet. This may be a motor, a generator, or a linear motor, including a linear induction motor.

[0043]

[0064] Although the present subject matter has been described in language specific to structural features and / or process acts, it should be understood that the present subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. 1. A magnet assembly for generating a magnetic field in one of a rotor or a stator having a plurality of wire windings carrying an electrical current, the magnet assembly comprising: a plurality of fixed magnets arranged in a ring arrangement, each of the fixed magnets having a north pole and a south pole, the fixed magnets arranged in the ring arrangement such that fixed magnets having north poles facing towards the rotor or stator alternate with fixed magnets having south poles facing towards the rotor or stator, and slots are formed between the fixed magnets; and a plurality of rotatable magnets, each having a north pole and a south pole, disposed in respective slots formed between a fixed magnet having a north pole facing towards the rotor or stator and a fixed magnet having a south pole facing towards the rotor or stator, such that the rotatable magnets may rotate within the slots; a magnet assembly including: a driver assembly for rotating the rotatable magnet in the slot to vary the magnetic field generated by the magnet assembly in the rotor or stator, the driver assembly being configured to rotate the rotatable magnet between a first position where the magnetic field in the rotor or stator is enhanced and a second position where the magnetic field in the rotor or stator is canceled; Electrical machines including:

2. 2. The electric machine of claim 1, wherein each of the fixed magnets is generally I-shaped with concavely curved sides such that the slot formed between each pair of fixed magnets is generally cylindrical, and the fixed magnets have a plurality of magnet fixation lids that focus the magnetic field of the rotor assembly toward the stator assembly.

3. 3. The electric machine of claim 2, wherein each of the rotatable magnets includes a generally cylindrical body having a first end and a second end, the cylindrical body being composed of a first half-cylinder that includes the north pole of the rotatable magnet and a second half-cylinder that includes the south pole of the rotatable magnet, the first and second half-cylinders extending from the first end to the second end.

4. a second plurality of fixed magnets spaced apart on an outer surface of the rotor core in a second ring arrangement, each of the fixed magnets having a north pole and a south pole, the second plurality of fixed magnets arranged in the second ring arrangement such that fixed magnets having north poles facing toward the stator assembly alternate with fixed magnets having south poles facing toward the stator assembly, and slots are formed between the fixed magnets; and a second plurality of rotatable magnets, each rotatable magnet of the second plurality of rotatable magnets having a north pole and a south pole, and disposed in a respective slot formed between a fixed magnet having a north pole facing toward the stator assembly and a fixed magnet having a south pole facing toward the stator assembly such that the rotatable magnet may rotate within the slot; and a second magnet assembly including: The driver assembly rotates the second plurality of turns in the slots formed in the second plurality of fixed magnets to vary the magnetic field in the stator assembly.

2. The electric machine of claim 1, configured to rotate the rotatable magnet of a rotatable magnet between a first position in which the magnetic field in the stator assembly is enhanced and a second position in which the magnetic field in the stator assembly is canceled.

5. 5. The electric machine of claim 4, wherein the second magnet assembly is adjacent to the first magnet assembly such that a fixed magnet of the first plurality of fixed magnets having a north pole facing toward the stator assembly is adjacent to a fixed magnet of the second plurality of fixed magnets having a south pole facing toward the stator assembly, and a fixed magnet of the first plurality of magnets having a south pole facing toward the stator assembly is adjacent to a fixed magnet of the second plurality of magnets having a north pole facing toward the stator assembly.

6. The electric machine of claim 5 , wherein the rotatable magnets of the first plurality of rotatable magnets and the second plurality of rotatable magnets are coupled together to form a rotatable magnet assembly.

7. 7. The electric machine of claim 6, wherein each rotatable magnet assembly of the rotatable magnet assemblies has a first side and a second side, a rotatable magnet of the first plurality of rotatable magnets has a north pole disposed on the first side and a south pole disposed on the second side, and a rotatable magnet of the second plurality of rotatable magnets has a south pole disposed on the first side and a north pole disposed on the second side.

8. 8. The electric machine of claim 7, wherein every other rotatable magnet assembly is positioned at a 180 degree rotation relative to the remaining rotatable magnet assemblies.

9. 9. The electric machine of claim 8, wherein each of the fixed magnets is generally I-shaped with concavely curved sides such that the slot formed is generally cylindrical.

10. 10. The electric machine of claim 9, wherein each of the rotatable magnets of the first plurality of rotatable magnets and the second plurality of rotatable magnets includes a generally cylindrical body having a first end and a second end.

11. A storage section; a shaft disposed in the housing, the shaft being supported by at least one bearing assembly such that the shaft can rotate relative to the motor housing; a stator assembly disposed within the motor housing, the stator assembly including a stator core and a plurality of wire windings supported by the stator core; a rotor assembly coupled to the shaft and configured to rotate relative to the stator assembly to rotate the shaft, the rotor assembly comprising: a rotor core having a generally cylindrical outer surface; a magnet assembly for generating a magnetic field in the stator assembly, the magnet assembly comprising: a plurality of fixed magnets spaced about the outer surface of the rotor core in a ring arrangement, each of the fixed magnets having a north pole and a south pole, the fixed magnets being arranged in the ring arrangement such that fixed magnets having north poles facing toward the stator assembly alternate with fixed magnets having south poles facing toward the stator assembly, and slots are formed between the fixed magnets; a plurality of fixed magnets; and a plurality of rotatable magnets, each having a north pole and a south pole, disposed in respective slots formed between a fixed magnet having a north pole facing toward the stator assembly and a fixed magnet having a south pole facing toward the stator assembly, such that the rotatable magnets may rotate within the slots; a magnet assembly including: a driver assembly for rotating each of the rotatable magnets in the slots to vary the magnetic field in the stator assembly, the driver assembly being configured to rotate the rotatable magnet between a first position in which the magnetic field in the stator assembly is enhanced and a second position in which the magnetic field in the stator assembly is canceled; a rotor assembly including: Electrical machines including:

12. 12. The electric machine of claim 11, wherein each of the fixed magnets is generally I-shaped with concavely curved sides such that the slot formed is generally cylindrical.

13. 13. The electric machine of claim 12, wherein each rotatable magnet of the rotatable magnets includes a generally cylindrical body having a first end and a second end, the cylindrical body being composed of a first half-cylinder that includes the north pole of the rotatable magnet and a second half-cylinder that includes the south pole of the rotatable magnet, the first and second half-cylinders extending from the first end to the second end.

14. 12. The electric machine of claim 11, wherein each of the rotatable magnets includes a planetary gear, and the drive assembly includes a ring gear engaged with the planetary gear and a motive device having a drive gear engaged with the ring gear, the motive device turning the drive gear which turns the ring gear to turn the planetary gear which rotates the rotatable magnet in the slot.

15. a second plurality of fixed magnets spaced apart on the outer surface of the rotor core in a second ring arrangement, each of the fixed magnets having a north pole and a south pole, the second plurality of fixed magnets being arranged in the second ring arrangement such that fixed magnets having north poles facing toward the stator assembly alternate with fixed magnets having south poles facing toward the stator assembly, and slots are formed between the fixed magnets; and a second plurality of rotatable magnets, each rotatable magnet of the second plurality of rotatable magnets having a north pole and a south pole, and disposed in a respective slot formed between a fixed magnet having a north pole facing toward the stator assembly and a fixed magnet having a south pole facing toward the stator assembly such that the rotatable magnet may rotate within the slot; and a second magnet assembly including: the driver assembly is configured to rotate the rotatable magnets of the second plurality of rotatable magnets in the slots formed in the second plurality of fixed magnets to vary the magnetic field in the stator assembly, and to rotate the rotatable magnets between a first position where the magnetic field in the stator assembly is enhanced and a second position where the magnetic field in the stator assembly is canceled.

12. The electric machine of claim 11.

16. 16. The electric machine of claim 15, wherein the second magnet assembly is adjacent to the first magnet assembly such that a fixed magnet of the first plurality of fixed magnets having a north pole facing toward the stator assembly is adjacent to a fixed magnet of the second plurality of fixed magnets having a south pole facing toward the stator assembly, and a fixed magnet of the first plurality of magnets having a south pole facing toward the stator assembly is adjacent to a fixed magnet of the second plurality of magnets having a north pole facing toward the stator assembly.

17. The electric machine of claim 16 , wherein the rotatable magnets of the first plurality of rotatable magnets and the second plurality of rotatable magnets are coupled together to form a rotatable magnet assembly.

18. 18. The electric machine of claim 17, wherein each rotatable magnet assembly of the rotatable magnet assemblies has a first side and a second side, a rotatable magnet of the first plurality of rotatable magnets has a north pole disposed on the first side and a south pole disposed on the second side, and a rotatable magnet of the second plurality of rotatable magnets has a south pole disposed on the first side and a north pole disposed on the second side.

19. 20. The electric machine of claim 18, wherein every other rotatable magnet assembly is positioned at a 180 degree rotation relative to the remaining rotatable magnet assemblies.

20. 20. The electric machine of claim 19, wherein each of the fixed magnets is generally I-shaped with concavely curved sides such that the slot formed is generally cylindrical, and each of the rotatable magnets of the first and second plurality of rotatable magnets includes a generally cylindrical body having a first end and a second end.

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