Patent Publication Number: US-2022231572-A1

Title: Hollow, magnetic flywheel and related generator systems

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from U.S. Prov. App. No. 63/140,057 filed on Jan. 21, 2021, the entirety of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     Generators may be used to generate electricity using other energy sources. In particular, generators may produce electricity by rotating one or more permanent magnets to create a varying magnetic field that induces an electric current, which is output by the generator. 
     SUMMARY 
     The present disclosure includes new and innovative systems and methods for improved power generation and/or energy storage. 
     In an example, a flywheel is provided for use in a generator. The flywheel includes a plurality of hollow disks. Each hollow disk of the plurality of hollow disks includes a plurality of magnets angularly distributed around the hollow disk and a plurality of attachment points. The flywheel also includes a plurality of disk attachment brackets fastened to the plurality of hollow disks via the plurality of attachment points. The plurality of hollow disks may be spaced to accommodate a stator disk positioned between adjacent hollow disks. 
     In an example, a generator is provided that includes a flywheel. The flywheel may include a plurality of hollow disks containing a plurality of magnets angularly distributed around the plurality of hollow disks and a plurality of disk attachment brackets fastened to the plurality of hollow disks. The generator may also include a plurality of stator disks positioned between adjacent hollow disks of the plurality of hollow disks. The plurality of stator disks may contain a plurality of coils angularly distributed around the plurality of stator disks. 
     In an example, a method is provided that includes assembling, with a plurality of disk attachment brackets, a plurality of hollow disks into a plurality of flywheel sections. The plurality of hollow disks may contain a plurality of magnets. The method may further include positioning, between adjacent hollow disks of the plurality of hollow disks, a plurality of stator disks containing a plurality of coils. The method may also include assembling the plurality of flywheel sections into a flywheel, attaching the flywheel at a single point in a generator, and rotating the flywheel while keeping the stator disks stationary to generate electrical current output by the generator. 
     In an example, a flywheel for use in a generator is provided. The flywheel includes a plurality of flywheel sections. Each flywheel section may include a plurality of hollow disks spaced to accommodate one or more stator disks, and a plurality of brackets angularly distributed around the hollow disks. The plurality of brackets are configured to receive permanent magnets. Each of the plurality of flywheel sections is hollow along an axis of rotation. At least one of the plurality of flywheel sections is formed from a single piece of material as a single structure using additive manufacturing. 
     In an example, a device is provided. The device includes a plurality of rotor disks disposed in a coaxial arrangement and configured to rotate about a rotor axis. The plurality of rotor disks includes a first disk and a second disk adjacent to the first disk in the coaxial arrangement. The device also includes a first plurality of magnets disposed in the first disk. The first plurality of magnets is angularly distributed about the rotor axis according to a distribution pattern. The device also includes a second plurality of magnets disposed in the second disk. The second plurality of magnets is angularly distributed about the rotor axis according to the distribution pattern. First angular positions of the first plurality of magnets about the rotor axis are offset from corresponding second angular positions of the second plurality of magnets. 
     The features and advantages described herein are not all-inclusive and, in particular, many additional features and advantages will be apparent to one of ordinary skill in the art in view of the figures and description. Moreover, it should be noted that the language used in the specification has been principally selected for readability and instructional purposes, and not to limit the scope of the disclosed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  is a perspective view of a generator according to an exemplary embodiment of the present disclosure. 
         FIG. 1B  is a top view of the generator of  FIG. 1A . 
         FIG. 1C  is a detailed view of an example bearing attachment point of the generator of  FIG. 1A . 
         FIG. 2  is a side view of a generator according to an exemplary embodiment of the present disclosure. 
         FIG. 3  illustrates an example base for use in a generator according to an exemplary embodiment of the present disclosure. 
         FIGS. 4A-4C  illustrate an example stator disk for use in a generator according to an exemplary embodiment of the present disclosure. 
         FIGS. 5A-5C  illustrate an example flywheel section for use in a generator according to an exemplary embodiment of the present disclosure. 
         FIGS. 6A-6C  illustrate another example flywheel section for use in a generator according to an exemplary embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Certain generator designs may include flywheels that contain one or more permanent magnets. These flywheels may then be rotated (e.g., by a motor) to generate the electric current output by the generator. Such conventional flywheels are typically solid in construction. For example, conventional flywheels are typically formed from a solid permanent magnet. Such configuration allows for a larger electric current to be generated for each rotation of the flywheel. However, such flywheels also require greater energy to rotate, as the solid core of the flywheels increases the weight of the flywheel. Furthermore, solid cores have comparatively low moments of inertia, which can cause the flywheels to lose rotational speed (and corresponding power output) in certain operational scenarios, such as when heavy loads are connected to the generator. 
     Therefore, there exists a need for a generator designed to include and use a hollow flywheel to generate electric current. One solution to this problem is to use a flywheel created from multiple disks. The disks may include arrangements of magnets that are radially arranged near an outer edge of the disks. The disks may be hollow and may be axially aligned into one or more sections to form a flywheel for use in a generator. Stator disks may be arranged between the disks of the flywheel. The stator disks may contain coils of wire in which electrical current is generated as the flywheel rotates. Such designs may reduce the overall weight of the flywheel and/or may increase the moment of inertia for the flywheel, by concentrating the mass of the flywheel near the outer edge of the flywheel. 
       FIGS. 1A-1B  illustrate a generator  100  according to an exemplary embodiment of the present disclosure. In particular,  FIG. 1A  depicts a perspective view of the generator  100  and  FIG. 1B  depicts a top view of the generator  100 . The generator  100  includes a flywheel  102 , which may rotate to generate power output by the generator  100 . The generated power may be provided to an electrical load of the generator. In certain implementations, the flywheel  102  may be oriented vertically within the generator  100  as depicted. In other implementations, the flywheel  102  may be oriented horizontally within the generator  100 . Rotation of the flywheel  102  may be powered at least in part by a motor  114 . The motor  114  may be positioned near one end of the flywheel  102 . For example, as depicted, the motor  114  may be positioned at a bottom end of the generator  100 . The motor  114  may be used to initially power the rotation of the flywheel  102 . For example, the motor  114  may be used to initialize rotation of the flywheel  102 . In additional or alternative implementations, the motor  114  may continue to power the rotation of the flywheel  102  after initializing. The motor  114  may be powered from an alternative energy source, such as fossil fuels, solar power, wind power, or any other energy source. 
     The flywheel  102  may be formed from one or more flywheel sections  104 ,  106  (only a subset of which are numbered in  FIG. 1A ). The flywheel sections  104 ,  106  may be formed from one or more disks  108 ,  110 ,  112 . The disks  108 ,  110 ,  112  may include magnets positioned near an outer edge of the disks. Stator disks containing coils of wire (discussed further below) may be positioned between the disks  108 ,  110 ,  112 . When the flywheel  102  is rotated, the disks  108 ,  110 ,  112 , may rotate between the stator disks, causing the magnets to induce an electric current output by the generator  100 . As discussed further below, the disks  108 ,  110 ,  112  may be substantially hollow in design, which may reduce the overall weight of the flywheel  102  and/or may increase the moment of inertia for the flywheel  102  when in operation). The flywheel sections  104 ,  106  may be joined together to form the flywheel  102 . In this way, the flywheel sections  104 ,  106  may enable modular construction of the flywheel  102 . Such modular construction may allow for customizable design and/or assembly of generators configured for a particular power output. For example, rather than having to redesign a flywheel for larger power outputs, a larger flywheel can be constructed by combining additional flywheel sections  104 ,  106  to create a longer and larger flywheel capable of outputting more power (e.g., in a larger generator). In certain instances, electric current output by V generator  100  may be processed by a power converter. For example, the power converter may receive the current output by the generator  100  and may convert the currents to power with one or more desired characteristics (e.g., desired voltage, desired AC frequency). In one specific example, the power converter may convert the current from the generator  100  to 120 V, 60 Hz current. Another specific example, the power converter may convert the current from the generator  100  to 240 V, 50 Hz current. 
     The generator  100  also includes a top plate  120  and side plates  118 . The top plate  120  may support the flywheel  102  during operation within the generator  100 . The top plate  120  includes a bearing attachment point  122 , from which the flywheel  102  may be suspended during operation. The top plate  120  may also be configured to protect the generator  100  and associated internal components, such as the flywheel  102  and the disks  108 ,  110 ,  112 . The side plate  118  may be positioned to protect the generator internal components in the side. For example, once fully assembled, the generator  100  may include side panels on all four sides of the generator  100  (e.g., left, right, front, and back sides). As depicted, the generator  100  may omit one of the side plates  118  to enable visibility of the internal components, such as the flywheel  102 . 
     In some examples, the flywheel  102  is disposed in a vacuum chamber. For example, the side plates  118  (including a side plate (not shown) inserted to cover a front side of the generator  100 ) as well as the top plate  120 , when assembled, may form an enclosure for the flywheel  102  from which air is pumped out to form a vacuum chamber for the flywheel  102 . With this arrangement, reduced air friction during rotation of the flywheel can be achieved to further improve the efficiency of the generator  100 . 
       FIG. 1C  illustrates a detailed view of the bearing attachment point  122  of the generator  100  according to an exemplary embodiment of the present disclosure. To reduce friction, in some examples, the flywheel  102  may be suspended from a single point at the top of the generator  100 . In particular, the flywheel  102  may be suspended from a bearing attachment point  122  located on a top plate  120  of the generator  100 . In particular, a top portion  128  of the flywheel  102  may include a flywheel attachment bracket  126 . A bearing housing  124  may be attached to the top plate  120 . The bearing housing  124  may include multiple bearings (e.g., ball bearings, magnetic bearings) distributed throughout a bottom surface of the bearing housing  124 . The flywheel attachment bracket  126  may rest on top of the bearings within the bearing housing  124 . In this way, the weight of the flywheel  102  may be supported from a single point of the flywheel attachment bracket  126 . Supporting the flywheel  102  in this way they reduce the overall friction imparted on the flywheel  102  while rotating, thereby increasing the power output and efficiency of the generator  100 . In additional or alternative limitations, it should also be understood that the way to the flywheel  102  may be supported from multiple points of the flywheel attachment bracket  126  (e.g., supported by multiple bearings). 
       FIG. 2  illustrates a side view of the generator  100  according to an exemplary embodiment of the present disclosure. As can be seen in the side view, the flywheel  102  includes five flywheel sections  104 ,  106 ,  200 ,  202 ,  204 . Each flywheel section  104 ,  106 ,  200 ,  202 ,  204  is made from four disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 . The disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  may contain permanent magnets located near an outer edge of the disks. Between the disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  are stator disks  218 ,  220 ,  222  (only a subset of which are numbered). The stator disks  218 ,  220 ,  222  may contain coils of wire in which an electric current is induced by the magnets from the disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  when the flywheel  102  rotates. In particular, the stator disks  218 ,  220 ,  222  may remain stationary when the flywheel  102  rotates and may be fixed to a housing of the generator  100 . 
     The flywheel sections  104 ,  106 ,  200 ,  202 ,  204  may be assembled by joining multiple disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 . In certain instances, stator disks  218 ,  220 ,  222  may be positioned between the disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  during assembly. For example, in certain implementations, the disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  and stator disks  218 ,  220 ,  222  may be spaced from one another such that the distance between the magnets in the disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  and coils of wire in the stator disks  218 ,  220 ,  222  is less than or equal to 0.5 inches (e.g., less than 0.25 inches, less than 0.1 inches, less than 0.5 inches). Assembled flywheel sections  104 ,  106 ,  200 ,  202 ,  204  may then be joined together to form a complete flywheel  102  for use within a generator  100 . In certain implementations, each flywheel section  104 ,  106 ,  200 ,  202 ,  204  may be a discrete assembly capable of being independently added to or removed from the flywheel  102 . For example, the disks  212 ,  214 ,  216  of a flywheel section  106  may be joined together to form an assembly capable of staying assembled when separated from the other flywheel sections  104 ,  106 ,  200 ,  202 ,  204 . In additional or alternative implementations, all flywheel sections  104 ,  106 ,  200 ,  202 ,  204  may be assembled and stacked together before being joined as a single flywheel  102 . 
     It should be understood that the flywheel  102  depicted in  FIG. 2  is merely exemplary, and additional or alternative flywheel designs may be used in other implementations. For example, certain generators may use flywheels  102  containing more or fewer than five flywheel sections  104 ,  106 ,  200 ,  202 ,  204 . For example, generators designed to output more power may include more flywheel sections (e.g., six or more flywheel sections). As another example, generators designed to output less power may include fewer flywheel sections (e.g., four or fewer flywheel sections). In still further implementations, the number of disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  214 ,  216  included in each flywheel section  104 ,  106 ,  200 ,  202 ,  204  may differ. As explained further below, certain configurations of the disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  may include magnets arranged to provide magnet propulsion as the flywheel rotates. In such instances, the number of disks  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  may be selected to maximize the magnetic propulsion while also balancing the number of magnets and coils of wire in the generator  100 . In some examples, the generator  100  harnesses the magnetic energy from the magnets on the flywheel disks to generate the electrical energy in the coils and kinetic energy (e.g., magnetic propulsion) to facilitate further rotation of the flywheel  102 . For example, certain implementations may include five disks in particular flywheel sections and/or three disks in particular flywheel sections. Further, the number of disks may differ for certain flywheel sections  104 ,  106 ,  200 ,  202 ,  204 . For example, a first flywheel section may include three disks, a second flywheel section may include four disks, and a third flywheel section may include five disks. 
     The number of stator disks in the flywheel sections  104 ,  106 ,  200 ,  202 ,  204  may also differ in various implementations. For instance, in the generator  100 , there is one more stator disk  218 ,  220 ,  222  in each flywheel section  104 ,  106 ,  200 ,  202 ,  204 , such that each disk  108 ,  110 ,  112 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216  is positioned between two stator disks  218 ,  220 ,  222 . Certain implementations may differ from the depicted configuration. For example, certain flywheels may include the same number of flywheel disks and stator disks. As another example, certain flywheels may include fewer (e.g., one fewer) stator disks than flywheel disks. 
       FIG. 3  illustrates a base  300  of the generator according to an exemplary embodiment of the present disclosure. For example, the base  300  may be an exemplary implementation of the base of the generator  100 . The base  300  includes a motor  114  of the generator  100 . The base  300  further includes a bottom attachment point  302  for the flywheel  102 . The bottom attachment point may provide a single point of attachment to a bottom portion of the flywheel  102 , or may provide multiple points of attachment, similar to the bearing attachment point  122 . In certain implementations, the bottom attachment point  302  may include one or more magnets position to provide a lifting force on the bottom of the flywheel  102 , to reduce the overall friction on the flywheel  102  as the flywheel  102  rotates. In practice, the bottom attachment point  302  may include one or more bearings (e.g., ball bearings, magnetic bearings), similar to the bearing attachment point  122 . 
     The base  300  also includes multiple stabilization magnets  304 ,  306 ,  308  (only a subset of which are numbered). The stabilization magnets  304 ,  306 ,  308  are positioned radially along an upper portion of the base  300 . In particular, the stabilization magnets  304 ,  306 ,  308  may be positioned near the bottom of the flywheel  102 . The magnets  304 ,  306 ,  308  may be arranged to oppose the magnetic fields of the magnets within the disks of the flywheel  102 . Such configurations may provide both a lifting force on the bottom of the flywheel  102  (reducing friction on the flywheel  102  with the flywheel  102  rotates) and may prevent the flywheel  102  from wobbling or otherwise tilting an operation. In practice, this may result in reduced energy required to maintain rotation of the flywheel  102 , improving overall output efficiency and spin downtime for the flywheel  102 . The stabilization magnets  304 ,  306 ,  308  may also reduce wobbling or other off-axis rotations of the flywheel  102  while rotating, which may prevent damage to components of the generator  100  and/or may improve the operating efficiency of the generator  100 . 
       FIGS. 4A-4C  illustrate a stator disk  400  for use in a generator according to an exemplary embodiment of the present disclosure. For example, the stator disk  400  may be positioned between disks of a flywheel  102  of the generator  100 . The stator disk  400  may include one or more coils of wire. For example, the stator disk  400  includes multiple brackets  402 ,  404 ,  406  and grooves  414 ,  416 ,  418  (only a subset of which are numbered). Coils of wire (not depicted) may be wound around the brackets  402 ,  404 ,  406  and in the grooves  414 ,  416 ,  418  within the disk  400 . In certain implementations, the same size wire may be used for all coils of the stator disk  400 . In additional or alternative implementations, different sizes of wire may be used for different coils of the stator disk  400 . Furthermore, in certain implementations, all of the mounting points  402 ,  404 ,  406  may include coils of wire. In other implementations, only a subset of the mounting points  402 ,  404 ,  406  may include coils of wire. 
     The stator disk  400  also includes attachment points  408 ,  410 ,  412 . The attachment points  408 ,  410 ,  412  may be used to attach the stator disk  400  so that the stator disk  400  stays in place while the flywheel rotates. 
       FIGS. 5A-5C  illustrate a flywheel section  500  for use in a generator  100  according to an exemplary embodiment of the present disclosure.  FIG. 5A  is a perspective view of the flywheel section  500 . The flywheel section  500  is assembled from four disks  502 ,  504 ,  506 ,  508 . The disks  502 ,  504 ,  506 ,  508  are joined together using disk attachment brackets  510  (only one of which is numbered). Disk attachment brackets  510  may attach to the disks  502 ,  504 ,  506 ,  508  using multiple bracket attachment points  512 ,  514 ,  516  bracket attachment points  512 ,  514 ,  516  may be fastened to attachment points of the disks  502 ,  504 ,  506 ,  508 . For example, once a flywheel section  500  (or an entire flywheel  102 ) is assembled, bolts (e.g., carbon fiber bolts, steel bolts) may be threaded through the entire length of the flywheel section  500  (or flywheel  102 ) within the bracket attachment points  512 ,  514 ,  516 . The bolts may then be tightened to fasten together the disks  502 ,  504 ,  506 ,  508  and the disk attachment brackets  510 , thereby forming a flywheel section  500  and/or a flywheel  102 . Although not depicted in the flywheel section  500 , when finally assembled one or more stator disks  218 ,  220 ,  222 ,  400  may be positioned between the disks  502 ,  504 ,  506 ,  508  (e.g., surrounding the disk attachment brackets  510 ). 
     The disks  502 ,  504 ,  506 ,  508  include brackets  524 ,  526 ,  528 ,  530  radially arranged along an exterior portion of the disks  502 ,  504 ,  506 ,  508 . The brackets  524 ,  526 ,  528 ,  530  may receive permanent magnets. In certain implementations, the disks  502 ,  504 ,  506 ,  508  may be arranged within the flywheel section  500  such that the brackets  524 ,  526 ,  528 ,  530  are helically arranged around the exterior of the flywheel section  500  (e.g., to form a spiraling pattern). This arrangement can be seen in the changing angular position of the brackets  524 ,  526 ,  528 ,  530  within adjacent disks  502 ,  504 ,  506 ,  508 . 
       FIG. 5B  is a top view of the flywheel section  500 . In the illustration of  FIG. 5B , an axis of rotation  590  of the flywheel section  500  extends through the page (e.g., in a perpendicular direction. For purposes of illustration, some features (e.g., brackets  526 ,  528 ,  530 , etc.) of the disks  504 ,  506 ,  508  below the disk  502  are projected onto the illustration of disk  502  in  FIG. 5B  using dashed lines. As shown in  FIG. 5B , the top view of the flywheel section  500  demonstrates that the brackets  524 ,  526 ,  528 ,  530  have different angular positions about the axis  590  once the disks  502 ,  504 ,  506 ,  508  are assembled. In an example, the disks  502 ,  504 ,  506 ,  508  are attached (e.g., via the supports  510 , etc.) such that the disks  502 - 508  simultaneously rotate about axis  590  to maintain the relative (e.g., staggered) angular positions of the brackets  524 - 530 , etc. during rotation of the disks  502 - 508 . 
     In some examples, assembling flywheel section  500  as shown in  FIGS. 5A-5B  may reduce an overall weight of a complete flywheel  102  used within a generator. In particular, by assembling the flywheel sections  500  from hollow disks  502 ,  504 ,  506 ,  508 , the overall weight of the flywheel  102  may be reduced by removing excess weight for interior portions of the disks. Similarly, the disk attachment bracket  510  may be designed for reduced weight. In some examples, the disk attachment bracket  510  may include one or more openings  518 ,  520 ,  522  that are empty to reduce the overall weight of the disk attachment bracket  510 , while still ensuring sufficient structural rigidity to sustain operating loads for the flywheel  102 . Furthermore, the disks  502 ,  504 ,  506 ,  508  and/or the disk attachment bracket  510  may be formed from materials selected to reduce the overall weight of the assembled flywheel section  500 . For example, the disks  502 ,  504 ,  506 ,  508  and the disk attachment bracket  510  may be assembled from plastic (e.g., ABS plastic) and/or lightweight metals (e.g., titanium, aluminum). As will be appreciated by one skilled in the art in light of the present disclosure, however, additional or alternative materials may be used to form one or more disks  502 ,  504 ,  506 ,  508  and/or disk attachment brackets  510 , such as steel, carbon fiber, and the like. 
     In some examples, rather than assembling flywheel section  500  from multiple separate hollow disks  502 ,  504 ,  506 ,  508  and multiple disk attachment brackets  510 , the flywheel section  500  may alternatively be formed as a single physical structure using a single piece of material (e.g., a single, contiguous carbon fiber component). In such instances, the flywheel section  500  formed by a single piece of material may have a similar geometry to the hollow disks  502 ,  504 ,  506 ,  508  and disk attachment brackets  510  once assembled. In certain implementations, such flywheel sections  500  may be manufactured or created using one or more additive techniques, such as 3D printing. In certain implementations, forming flywheel sections  500  from single pieces of material may reduce variance of the components (e.g., weight distribution of the disks  502 ,  504 ,  506 ,  508  and disk attachment brackets  510 ). For example, a flywheel section  500  formed from single pieces of material may be better balanced in operation, allowing for higher rotational speeds and/or higher operating efficiencies. Furthermore, in some instances, flywheel sections  500  formed from single pieces of material may reduce assembly time, as individual hollow disks  502 ,  504 ,  506 ,  508  and disk attachment brackets  510  do not need to be separately assembled to form the flywheel section  500 . 
       FIG. 5C  illustrates a conceptual view  550  of the flywheel section  500 . In particular, the conceptual view  550  depicts partial cross-section views of portions of the disks  502 - 508  where the brackets  524 - 530  are located. Relatedly, as depicted in the conceptual view  550  of  FIG. 5C , magnets  552 ,  554 ,  556 ,  558  may be disposed in the brackets  524 ,  526 ,  528 ,  530  of the disks  502 ,  504 ,  506 ,  508  and positioned such that opposing magnetic fields of magnets  552 ,  554 ,  556 ,  558  in adjacent disks  502 ,  504 ,  506 ,  508  are aligned. In the illustrated example of  FIG. 5C , northern poles of all the magnets  552 ,  554 ,  556 ,  558 , etc. in the respective disks  502 - 508  are magnetically aligned and oriented in a same direction (e.g., toward a top of the flywheel section  500 ), although it is noted that other implementations are possible. Furthermore, in some implementations, the brackets  524 ,  526 ,  528 ,  530  may contain metal shielding (e.g., using non-magnetic metals) to surround one or more sides of the magnets (e.g.,  502 - 508 , etc.) placed within the brackets  524 ,  526 ,  528 ,  530 , etc. In one example, the brackets  524 ,  526 ,  528 ,  530  may contain copper surrounding the magnets. In certain implementations, such metals may increase fields definition for the magnets within the brackets  524 ,  526 ,  528 ,  530 , thereby increasing electromagnetic wave strengths produced by the generator and increasing the overall operating efficiency and power output of the generator. 
       FIGS. 6A-6C  illustrate another example flywheel section  600 , according to an example embodiment. In particular, flywheel section  600  may represent an alternative embodiment of a flywheel section such as flywheel section  500 .  FIG. 6A  is a perspective view of the flywheel section  600 .  FIG. 6B  is a top view of the flywheel section  600 . 
     As shown, the flywheel section  600  includes a plurality of rotor disks  602 - 610  disposed in a coaxial arrangement about a center or rotor axis  690 . Although the rotor disks  602 - 610  are shown to have circular shapes, other shapes (e.g., oval shapes, etc.) of the rotor disks  602 - 610  are possible as well. 
     The disks  601 - 610  may be similar to the disks  502 - 508 . For example, the disks  602 - 610  may be configured to rotate simultaneously about the rotor axis  690  (e.g., which may be similar to the axis  590 ) and may remain in the relative coaxial arrangement shown during the rotation about the axis  690 . To that end, it is noted that some components of the flywheel section  600  are omitted from the illustrations of  FIGS. 6A-6C  for convenience in description. For example, although not shown, flywheel section  600  may include disk attachment brackets, similar to disk attachment bracket  510  for example, configured to attach the disks  602 - 610  in the coaxial arrangement shown. For instance, the disk attachment points  652 - 656  can be used to attach each respective disk  602 - 610 , etc. to a respective disk attachment between the disk and an adjacent disk. 
     Each disk  602 - 610  includes a plurality of brackets, exemplified by brackets  612 - 620 , disposed on the disk according to a same distribution pattern as that of magnets disposed on other disks  602 - 610 . For example, the brackets on disk  602  (exemplified by bracket  612 ) may be spaced apart by a same bracket spacing offset (e.g., 36 degrees) about the axis  690 . In general, the brackets  612 - 620 , etc., may each be configured to receive a permanent magnet, similarly to the brackets  524 - 530  of flywheel section  500 . However, as shown, the brackets  612 - 620 , etc., have a square shape which may be shaped to receive square magnets. 
     For example,  FIG. 6C  illustrates a top view of the disk  610 . In the illustrated example, a plurality of magnets  630 - 638 , etc., are distributed about axis  690  according to the distribution pattern. Further, each magnet  630 - 638  is disposed in a respective bracket of the disk  610 . For example, the magnet  630  may be disposed in the bracket  620 , and so on. Further, as noted above, each of the magnets  630 - 638 , etc. has a respective first surface (along the surface of the page) that faces the disk  608  and that has a square shape. In alternate examples, the respective first surfaces of the magnets  630 - 638 , etc. may have a different shape (e.g., round shape such as the round shapes of brackets  524 - 530 , rectangular shape, etc.). The magnets  630 - 638 , etc., may include any type of permanent magnet, such as neodymium magnets for example. 
     In some examples, respective magnetic north poles of the plurality of magnets  630 - 638 , etc., are positioned at a first side of the disk  610  (i.e., at the side shown in  FIG. 6C ), and each of the plurality of magnets  630 - 638  extends axially through the disk  610 , similarly to the orientation of the magnets  552 - 558  shown in  FIG. 5C  for example. 
     Returning now to  FIG. 6B , it is noted that portions of the disks  604 - 610  (e.g., the brackets  614 - 620 ) are projected onto the illustration of the top disk  602  in  FIG. 6B  using dashed lines for convenience in description. In particular, as best shown in  FIG. 6B , angular positions of the brackets/magnets on each disk are offset from corresponding angular positions of an adjacent disk by a staggering angular offset. By way of example, where an angular position of bracket  612  is 0 degrees and the staggering angular offset is 6 degrees, the angular positions of brackets  614 - 620  may be, respectively, 6 degrees, 12 degrees, 18 degrees, and 24 degrees about axis  690 . Thus, in some examples, a spacing angular offset (e.g., 36 degrees, etc.) between adjacent magnets on a same disk (e.g., between magnets  630  and  632 ) may be greater than a staggering angular offset (e.g., 6 degrees, etc.) between corresponding magnets on adjacent disks (e.g., between bracket  612  and  614 ). 
     In the illustrated example, the plurality of magnets (e.g.,  630 - 638 , etc.) on each disk  602 - 610  are at a same radial distance to the axis  690 . In alternate examples, magnets on a first disk may be instead disposed at a different radial distance to axis  690  than magnets on a second disk. 
     Aspects of the subject matter described herein may be useful alone or in combination with one or more other aspects described herein. 
     In a first exemplary aspect, a flywheel is provided for use in a generator. The flywheel includes a plurality of hollow disks. Each hollow disk of the plurality of hollow disks includes a plurality of magnets angularly distributed around the hollow disk and a plurality of attachment points. The flywheel also includes a plurality of disk attachment brackets fastened to the plurality of hollow disks via the plurality of attachment points. The plurality of hollow disks may be spaced to accommodate a stator disk positioned between adjacent hollow disks. 
     In a second exemplary aspect according to the first exemplary aspect, the plurality of disk attachment brackets fasten the plurality of hollow disks such that respective magnets of two or more adjacent disks are arranged in a helical pattern around the flywheel. 
     In a third exemplary aspect according to the first or second exemplary aspects, the flywheel is suspended within the generator from a single point. 
     In a fourth exemplary aspect according to any of the first through third exemplary aspects, the flywheel is suspended within the generator from multiple points. 
     In a fifth exemplary aspect according to any of the first through fourth exemplary aspects, the flywheel is balanced during operation by a plurality of stabilization magnets positioned at a base of the generator. 
     In a sixth exemplary aspect according to any of the first through fifth exemplary aspects, the flywheel includes a plurality of flywheel sections. Each of the plurality of flywheel sections may include at least a subset of the plurality of hollow disks and at least a subset of the plurality of disk attachment brackets. 
     In a seventh exemplary aspect according to any of the first through sixth exemplary aspects, each of the plurality of magnets is surrounded by a non-magnetic metal on at least one side. 
     In an eighth exemplary aspect according to any of the first through seventh exemplary aspects, the plurality of magnets have a same size. 
     In a ninth exemplary aspect according to any of the first through eighth exemplary aspects, a first subset of the plurality of magnets are larger than a second subset of the plurality of magnets. 
     In a tenth exemplary aspect according to any of the first through ninth exemplary aspects, the stator disks contain a plurality of coils. 
     In an eleventh exemplary aspect according to the tenth exemplary aspect, each of the plurality of coils is formed from wire of a same gauge. 
     In a twelfth exemplary aspect according to any of the tenth and eleventh exemplary aspects, a first subset of the plurality of coils are formed from wire with a larger gauge than a second subset of the plurality of coils. 
     In a thirteenth exemplary aspect, a generator is provided that includes a flywheel. The flywheel may include a plurality of hollow disks containing a plurality of magnets angularly distributed around the plurality of hollow disks and a plurality of disk attachment brackets fastened to the plurality of hollow disks. The generator may also include a plurality of stator disks positioned between adjacent hollow disks of the plurality of hollow disks. The plurality of stator disks may contain a plurality of coils angularly distributed around the plurality of stator disks. 
     In a fourteenth exemplary aspect according to the thirteenth exemplary aspect, the plurality of disk attachment brackets fasten the plurality of hollow disks such that respective magnets in two or more adjacent disks are arranged in a helical pattern around the flywheel. 
     In a fifteenth exemplary aspect according to any of the thirteenth and fourteenth exemplary aspects, the flywheel is suspended within the generator at a single point. 
     In a sixteenth exemplary aspect according to any of the thirteenth through fifteenth exemplary aspects, the flywheel is balanced during operation by a plurality of stabilization magnets positioned at a base of the generator. 
     In a seventeenth exemplary aspect according to any of the thirteenth through sixteenth exemplary aspects, the flywheel is formed from a plurality of flywheel sections. Each of the plurality of flywheel sections may include at least a respective subset of the plurality of hollow disks and at least a respective subset of the plurality of disk attachment brackets. 
     In an eighteenth exemplary aspect according to any of the thirteenth through seventeenth exemplary aspects, the plurality of magnets have a same size. 
     In a nineteenth exemplary aspect according to any of the thirteenth through eighteenth exemplary aspects, a first subset of the plurality of magnets are larger than a second subset of the plurality of magnets. 
     In a twentieth exemplary aspect according to any of the thirteenth through nineteenth exemplary aspects, the plurality of coils are formed from wire of a same gauge. 
     In a twenty first exemplary aspect according to any of the thirteenth through twentieth exemplary aspects, a first subset of the plurality of coils are formed from wire with a larger gauge than a second subset of the plurality of coils. 
     In a twenty second exemplary aspect according to any of the thirteenth through twenty first exemplary aspects, the flywheel is suspended in a vacuum chamber. 
     In a twenty third exemplary aspect according to any of the thirteenth through twenty second exemplary aspects, the flywheel is suspended in the generator via one or more magnetic bearings. 
     In a twenty fourth exemplary aspect, a method is provided that includes assembling, with a plurality of disk attachment brackets, a plurality of hollow disks into a plurality of flywheel sections. The plurality of hollow disks may contain a plurality of magnets. The method may further include positioning, between adjacent hollow disks of the plurality of hollow disks, a plurality of stator disks containing a plurality of coils. The method may also include assembling the plurality of flywheel sections into a flywheel, attaching the flywheel at a single point in a generator, and rotating the flywheel while keeping the stator disks stationary to generate electrical current output by the generator. 
     In a twenty fifth exemplary aspect according to the twenty fourth exemplary aspect, each of the plurality of stator disks is positioned such that a distance between the plurality of coils and respective adjacent hollow disks is less than or equal to 0.25 inches. 
     In a twenty sixth exemplary aspect, a flywheel for use in a generator is provided. The flywheel includes a plurality of flywheel sections. Each flywheel section may include a plurality of hollow disks spaced to accommodate one or more stator disks, and a plurality of brackets angularly distributed around the hollow disks. The plurality of brackets are configured to receive permanent magnets. Each of the plurality of flywheel sections is hollow along an axis of rotation. At least one of the plurality of flywheel sections is formed from a single piece of material as a single structure using additive manufacturing. 
     In a twenty seventh exemplary aspect, a device is provided. The device includes a plurality of rotor disks disposed in a coaxial arrangement and configured to rotate about a rotor axis. The plurality of rotor disks includes a first disk and a second disk adjacent to the first disk in the coaxial arrangement. The device also includes a first plurality of magnets disposed in the first disk. The first plurality of magnets is angularly distributed about the rotor axis according to a distribution pattern. The device also includes a second plurality of magnets disposed in the second disk. The second plurality of magnets is angularly distributed about the rotor axis according to the distribution pattern. First angular positions of the first plurality of magnets about the rotor axis are offset from corresponding second angular positions of the second plurality of magnets. 
     In a twenty eighth exemplary aspect according to the twenty seventh exemplary aspect, each of the first angular positions is offset from a corresponding one of the second angular positions by a stagger angular offset. 
     In a twenty ninth exemplary aspect according to any of the twenty seventh and twenty eighth exemplary aspects, adjacent magnets of the first plurality of magnets are angularly separated in the distribution pattern by a spacing angular offset. 
     In a thirtieth exemplary aspect according to the twenty ninth exemplary aspect, the spacing angular offset is greater than the stagger angular offset. 
     In a thirty first exemplary aspect according to any of the twenty seventh through thirtieth exemplary aspects, each of the first plurality of magnets is disposed at a same radial distance to the rotor axis. 
     In a thirty second exemplary aspect according to any of the twenty seventh through thirty first exemplary aspects, each of the second plurality of magnets is disposed at the same radial distance to the rotor axis. 
     In a thirty third exemplary aspect according to any of the twenty seventh through thirty second exemplary aspects, respective magnetic north poles of the first plurality of magnets are positioned at a first side of the first disk. Each of the first plurality of magnets extends axially through the first disk. 
     In a thirty fourth exemplary aspect according to any of the twenty seventh through thirty third exemplary aspects, a first surface of a given magnet of the first plurality of magnets is exposed at a first side of the first disk facing the second disk. 
     In a thirty fifth exemplary aspect according to the thirty fourth exemplary aspect, the first surface has a square shape. 
     In a thirty sixth exemplary aspect according to the thirty fourth exemplary aspect, the first surface has a round shape. 
     In a thirty seventh exemplary aspect according to any of the twenty seventh through thirty sixth exemplary aspects, at least one of the first plurality of magnets is a neodymium magnet. 
     The presently discussed generator designs and corresponding flywheels result in multiple unexpected and practical benefits when used in an operating generator. In some examples, a lower weight of the flywheel in the generator may be selected to reduce the overall energy required to initialize operation of the generator. Furthermore, by increasing the moment of inertia for the flywheel, the flywheel itself can continue spinning for longer and with less energy, improving the operating efficiency of the generator overall. Also, in examples, arranging magnets in a helical arrangement around the flywheel may further reduce the energy required to keep the flywheel spinning, as such an arrangement can create a propulsive magnetic force that continues to assist with propelling flywheel when in operation. Overall, these benefits can result in a significant overall improvement to the efficiency of the generator. 
     It should be understood that various changes and modifications to the examples described here will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.