FLYWHEEL VACUUM ENCLOSURE AND ADJUSTMENT SYSTEM

A system may include an enclosure base having a bottom surface and one or more side walls coupled with the bottom surface. A system may include an enclosure lid having a top surface, the enclosure lid coupling with the one or more side walls of the enclosure base to create an enclosed space, the enclosed space containing a massive flywheel, the massive flywheel having one or more axles. A system may include one or more bearings coupling the one or more axles to the enclosure base and the enclosure lid, the one or more bearings holding the one or more axles at an axis of rotation. Aspects of the invention include components coupled with the system, such as a vacuum assembly, adjustment and locking mechanisms, and other components.

BACKGROUND

The present disclosure relates to mechanical energy storage units. Implementations relate to flywheel-based mechanical energy storage units.

Currently, residential electricity customers, as well as electrical utilities, use various sources of electrical energy storage to offset varying electrical power production and use, such as the duck curve associated with solar or other renewable energy production. The variation in power production and usage has been further exacerbated with the increasing popularity of renewable power sources. These issues cause significant cost and other issues to utilities, power outages, and other issues.

Commonly, excess or backup power is stored in chemical storage, such as large chemical batteries. Unfortunately, chemical batteries suffer from many issues that make them undesirable at both a residential level and at a utility level. For example, chemical batteries may be very expensive, complex, and require numerous safeguards against fires. Chemical batteries are also ecologically unfriendly, as their production uses toxic chemicals, creates significant greenhouse gases, and results in significant material waste. Furthermore, chemical batteries have short lifespans because the batteries have a limited number of years and recharge cycles before they must be disposed of.

Previous solutions for mechanical energy storage have been overly complex, too large to be implemented at a residential level, not scalable for an electrical utility, or have faced other issues.

SUMMARY

In some aspects, the techniques described herein relate to a flywheel enclosure including: an enclosure base having a bottom surface and one or more side walls coupled with the bottom surface; an enclosure lid having a top surface, the enclosure lid coupling with the one or more side walls of the enclosure base to create an enclosed space, the enclosed space containing a massive flywheel, the massive flywheel having one or more axles; and one or more bearings coupling the one or more axles to the enclosure base and the enclosure lid, the one or more bearings holding the one or more axles at an axis of rotation.

In some aspects, the techniques described herein relate to a flywheel enclosure, further including: a plurality of reinforcing ribs reinforcing the bottom surface and the one or more side walls.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein: one or more seals are disposed on at least one of the enclosure base and the enclosure lid, the one or more seals sealing the enclosed space to provide a vacuum inside the enclosed space.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein: the enclosure base includes a top ring mounted to the one or more side walls, the top ring including a groove holding an O-ring seal; the enclosure lid mounts to the top ring via a plurality of fasteners, the O-ring seal sealing the enclosure lid to the top ring; and the one or more bearings include a top bearing coupled with the enclosure lid and a bottom bearing coupled with the enclosure base.

In some aspects, the techniques described herein relate to a flywheel enclosure, further including: a component mounting plate coupled with the enclosure lid, the component mounting plate including a plurality of mounting points for mounting flywheel accessory components to the enclosure lid, the flywheel accessory components including a vacuum assembly.

In some aspects, the techniques described herein relate to a flywheel enclosure, further including: a positioning mechanism coupled with the enclosure base, the positioning mechanism moving one or more of the one or more bearings and the massive flywheel within the enclosed space.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein the positioning mechanism includes: a nut bearing holder that holds a bottom bearing of the one or more bearings, the nut bearing holder having threads that cause the nut bearing holder to move the bottom bearing vertically when the nut bearing holder is rotated.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein: the nut bearing holder lifts the massive flywheel via the one or more bearings when the nut bearing holder is rotated.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein the enclosure base includes threaded ring around a perforation in the bottom surface, the threaded ring interacting with the threads of the nut bearing holder.

In some aspects, the techniques described herein relate to a flywheel enclosure, further including: a shipping support area coupled with the enclosure base and configured to vertically support the massive flywheel during shipping, the positioning mechanism configured to decouple the massive flywheel and the shipping support area.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein the shipping support area includes a shipping ring located around a perforation in the bottom surface, the one or more bearings extending through the perforation in the bottom surface.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein the positioning mechanism includes: a nut bearing holder that holds a bottom bearing of the one or more bearings, the nut bearing holder moving the one or more of the one or more bearings and the massive flywheel within the enclosed space when the nut bearing holder is rotated; and a nut locking mechanism that locks the nut bearing holder rotationally to the enclosure base.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein the nut locking mechanism includes: a retaining cap that holds the nut bearing holder to the enclosure base and encloses the one or more bearings in the enclosed space.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein the nut locking mechanism includes: a hex interface coupling with the nut bearing holder and the retaining cap, the hex interface allowing the nut bearing holder to be held by the retaining cap at a set of angles defined by the hex interface.

In some aspects, the techniques described herein relate to a flywheel enclosure, wherein: the flywheel enclosure includes one or more magnets coupled with the enclosure lid, the one or more magnets pulling the massive flywheel toward the enclosure lid; and the positioning mechanism is configured to lift the massive flywheel to increase the pulling force of the one or more magnets.

In some aspects, the techniques described herein relate to a flywheel system including: an enclosure base having a bottom surface and one or more side walls coupled with the bottom surface; an enclosure lid having a top surface, the enclosure lid coupling with the enclosure base to create an enclosed space, the enclosed space containing a massive flywheel, the massive flywheel including a massive cylinder and one or more axles, the massive flywheel rotating about the one or more axles, a motor being mounted to the enclosure lid and coupled with the one or more axles, the motor changing a rotational velocity of the massive flywheel; and one or more bearings coupling the one or more axles to the enclosure base and the enclosure lid, the one or more bearings holding the one or more axles at an axis of rotation.

In some aspects, the techniques described herein relate to a flywheel system, further including: a positioning mechanism coupled with the enclosure base, the positioning mechanism moving one or more of the one or more bearings and the massive flywheel within the enclosed space.

In some aspects, the techniques described herein relate to a flywheel system, wherein the positioning mechanism includes: a nut bearing holder that holds a bottom bearing of the one or more bearings, the nut bearing holder having threads that cause the nut bearing holder to move the bottom bearing vertically when the nut bearing holder is rotated.

In some aspects, the techniques described herein relate to a flywheel system, wherein: the nut bearing holder lifting the massive flywheel via the one or more bearings when the nut bearing holder is rotated.

In some aspects, the techniques described herein relate to a system including: an enclosure tub having a bottom surface and one or more side walls coupled with the bottom surface; an enclosure lid having a top surface, the enclosure lid coupling with the enclosure tub to create an enclosed space, the enclosed space containing a massive flywheel, the massive flywheel having one or more axles; one or more bearings coupling the one or more axles to the enclosure tub and the enclosure lid, the one or more bearings holding the one or more axles at an axis of rotation; and a positioning mechanism coupled with the enclosure tub, the positioning mechanism holding the one or more bearings, the positioning mechanism moving the massive flywheel vertically via the one or more bearings.

Other implementations of one or more of these aspects or other aspects include corresponding systems, apparatus, and computer programs, configured to perform the various actions and/or store various data described in association with these aspects. These and other implementations, such as various data structures for controlling the mechanical energy storage unit, may be encoded on tangible computer storage devices. Numerous additional features may, in some cases, be included in these and various other implementations, as discussed throughout this disclosure. It should be understood that the language used in the present disclosure has been principally selected for readability and instructional purposes, and not to limit the scope of the subject matter disclosed herein.

DETAILED DESCRIPTION

This description includes several improvements over previous solutions, such as those described in reference to the Background. A mechanical-energy storage unit is described herein along with its assembly and an assembly fixture. Some aspects of the technology include components that reduce vertical force by a massive flywheel on bearings, such as an improved magnetic lift system. Other aspects include bearings, magnetic couplings, clamping plates, and/or other systems that may further improve the mechanical energy storage unit.

In some implementations, one or two mechanical-energy storage units102may be installed at a residence to provide backup power in case of a power outage, to store electricity generated using residential solar panels, or to offset unevenness of power production and usage (e.g., an electrical utility may control the mechanical-energy storage unit102at a residence to address the balance energy use/production at the residence, nearby residences, or across the power grid). A mechanical-energy storage unit102may be buried next to an electrical panel or placed in a shed outside a residence, placed in a garage or utility room, or stored offsite.

In some implementations, multiple mechanical-energy storage units102may be coupled together to scale energy backup at a larger facility, such as a business, or by an electrical utility. For instance, many mechanical-energy storage units102may be placed at a facility, buried, or otherwise used by an electrical utility. The multiple mechanical-energy storage units102may be communicatively linked to each other or to a central server to control storage and distribution of the stored energy (e.g., by controlling the rotational frequency of a flywheel402to keep various flywheels402at efficient speeds).

Various implementations and features of flywheel energy storage systems (FESS) are described herein. These provide improvements over previous energy storage units including other flywheels402. For instance, the technology described herein provides an improved flywheel system or assembly, improved bearings, improved flywheel-motor couplings, improved flywheel housing, improved flywheel plates, improved assembly fixture, and method for assembly and use, among other improvements, features, and benefits.

For example, a flywheel402may include a rotatable mass component, which may comprise a plurality of stacking plates122, cylinders, or other components, one or more bolt or clamping plates120, one or more axle408members, and other features. For instance, the technologies described herein include a plurality of plates that may have contoured edges based on an associated support structure, which allows increased speeds while reducing failure modes. For instance, the support structure may include clamping plates120that apply pressure to stacking plates122, thereby inducing friction between the plates to keep them in place and transfer rotational momentum between the plates and one or more axles408. In some implementations, two clamping plates120may be clamped together by bolts or other fasteners, which thereby cause the clamping plates120to apply pressure on massive plates (e.g., in an axial direction), which may be referred to herein as stacking plates122, and increase the friction among the stacking plates122, which may, in some cases, allow the stacking plates122to be used without other fasteners, thereby improving safety and efficiency. Other features and benefits of the flywheel402are described below. Not only are the plates improved, but their support structure is improved, among other benefits. Further implementations and features allow the expansion, positioning, and use of the flywheel402thereby further improving its performance.

Among other improvements, the technologies described herein also include an improved support structure, such as an enclosure104, and support system, which may include, among other things, a sealed enclosure104, a lid-mounted vacuum assembly108, a magnetic coupling118, various bearings, and positioning mechanisms. The enclosure104may include a magnetic lift assist mechanism152that either entirely supports or partially supports the weight of the flywheel402(e.g., to reduce wear on bearings). The enclosure104may also include a transport surface and a lifting and adjustment mechanism that moves the position of the flywheel402internal to the enclosure104from a transport or storage position and adjusts it in an active position. The enclosure104may provide support for various components, such as a supercapacitor106, vacuum assembly, processor/controller/central processing unit, a motor110, and other components. The enclosure104may include various features for maintaining a vacuum, holding one or more bearings, positioning a flywheel402during use or transport, mitigating damage due to structural failures, and isolating vibration, among other features.

Other benefits and features are described throughout this disclosure, but it should be noted that other features and benefits are contemplated. Furthermore, while various implementations are described in reference to the figures, these are provided by way of example and their features may be expanded, modified, or removed. For instance, features described in reference to some implementations may additionally or be used with other implementations.

With reference to the figures, reference numbers may be used to refer to components found in any of the figures, regardless of whether those reference numbers are shown in the figure being described. Further, where a reference number includes a letter referring to one of multiple similar components (e.g., component 000a, 000b, and 000n), the reference number may be used without the letter to refer to one or all of the similar components. Further, it should be noted that while various example features and implementations are described throughout this disclosure and the figures, these examples are not exhaustive of every contemplated implementation, feature or permutation. For instance, while a certain feature may be described in reference to a first implementation, the feature may be used with a second implementation or the features, operations, etc., may otherwise be exchanged between the implementations.

The innovative technology disclosed in this document also provides novel advantages including the ability to integrate modern technology with conventional power infrastructure; enable rapid transition to renewable energy sources; use the power grid as a backup; store power locally in nodes and regionalized storage clusters of nodes; isolate and minimize the impact of power outages; whether caused by natural disasters, infrastructure failure, or other factors; provide affordable alternatives to expensive and environmentally unfriendly electrochemical batteries; provide consumers the option to be independent from carbon-based power sources; and decentralize electric power production.

FIGS.1A-1Dillustrate an example mechanical-energy storage unit102(MESU102) or flywheel assembly102from various angles and views. For example,FIG.1Aillustrates a front-top view,FIG.1Billustrates a cross section view,FIG.1Cillustrates a front-top view of another example MESU102or flywheel assembly102, andFIG.1Dillustrates a front-top view with an enclosure lid128removed to show a flywheel402inside a flywheel enclosure104of an example MESU102assembly.

The improved flywheel assembly102may be a mechanical-energy storage unit102with configurations and features that improve manufacturability while also providing redundancy, safety, and reliability that allow the flywheel assembly102to provide years of safe and relatively maintenance free operation in ways that were not previously possible, for example, as may be noted in the Background and elsewhere herein. Although various configurations are possible and contemplated, the illustrated example flywheel assembly102may include a vacuum enclosure104and support structure, a massive rotating flywheel402(not visible inFIG.1A) internal to the enclosure104, a motor-generator110that may be fully or partially external to the enclosure104and coupled with the flywheel402, a supercapacitor106, driver(s) and/or CPUs, inverter(s), circuit breakers, magnetic lift member(s)152(also referred to as magnetic lift components or mechanisms herein), bearings, physical or magnetic couplings118, a vacuum pump108, and various other components, as described below, although other implementations are possible and contemplated herein.

The enclosure104is an example of a support structure that supports various components of a flywheel assembly102. While example enclosures104are shown completely enclosed, in some implementations, an enclosure or other support structure may be open, such as a cage, frame, or other configuration.

The example flywheel assembly102may include, among other things, an enclosure104that is scalable to provide a vacuum, support to the flywheel402(not visible inFIG.1A), a mounting structure for various components of the assembly, and protection against mechanical failure, among other things. The example enclosure104for the flywheel402may be configured as a vacuum assembly case with reinforcement including features for coupling the flywheel402with the case, an improved shape, and an ability to adjust the flywheel402through the case. In some instances, a connection for creating and/or maintaining a vacuum may also be included with the case. Example implementations and features of the enclosure104may be described elsewhere herein, although other implementations are possible and contemplated.

The flywheel enclosure104may be mounted and/or isolated from a mounting structure by one or more feet114or legs, as noted below, and may include mounting structures for accommodating various components of the assembly. For example, a supercapacitor106may be mounted to a support structure of or attached to the enclosure104, which supercapacitor106may buffer energy entering/exiting the flywheel402, for instance, by assisting the motor110to spin the flywheel402up or receive energy therefrom.

Also, as described below, the enclosure104may provide mounting points or structures (e.g., a mounting brace132) for mounting a motor-generator110in line with the axis of rotation of the flywheel402, although, in other implementations, gears may be used to couple the motor-generator110with the flywheel402. The motor-generator110may be coupled with the flywheel402via one or more axle408components and, in some instances, a magnetic coupling118that allows a flywheel axle(s)408to remain physically decoupled from a motor-generator110rotor while still providing force to pass between them, although a physical coupling may also or alternatively be used, as described below. The motor-generator110may have an electrical connection to a supercapacitor106, inverter, driver, CPU, external grid connection or otherwise, which allows electrical current to flow into the motor-generator110to spin up the flywheel402or out of the motor-generator110to receive stored potential energy from the flywheel402.

The motor-generator110may have various configurations, as noted in further detail elsewhere herein. In some implementations, the motor-generator110may be an electrical-vehicle motor or other motor (e.g., a Hyper 9™ motor), such as a brushless alternating current motor (e.g., a 3 phase AC synchronous reluctance internal permanent magnet motor) that can free-wheel in order to allow the flywheel402to store power for a longer period of time. The motor size and configuration may vary depending on peak output/input and flywheel402size/speed requirements. For instance, a smaller, residential MESU102may include a smaller size flywheel402with a 30-40 KW motor while a larger, commercial (e.g., for a store, electrical utility, subdivision, etc.) may have a 300-500 kW motor, although other implementations are possible. The motor controller and/or CPU may be the same for various sizes of flywheels402or may vary depending on the implementation.

The motor-generator110may be coupled with the flywheel402using an axle408and bearing of the flywheel402/flywheel enclosure104. Similarly, in some implementations, the flywheel axle408and motor-generator110may be coupled using a flywheel motor coupling, which may include a direct connection, magnetic coupling118, friction clutch, torque converter, gearbox, or otherwise, as described in further detail below.

An example flywheel402(not visible inFIG.1A) may be housed in and/or supported by the enclosure104and components thereof. Example flywheels402and features thereof are described throughout this disclosure. For example, a flywheel402may include a plurality of stacking plates122held together by a support structure, such as clamping plates120(e.g., using compression and friction). The support structure may include one or more axles408that attach thereto and provide support to the flywheel402. As described in further detail elsewhere herein, the configuration of the support structure and axles408may allow flywheel plates to be used without the axle408perforating the plates. Depending on the implementation, the axle(s)408may be vertically and/or horizontally supported by other components or the flywheel enclosure104and may couple with a motor-generator110(e.g., as noted above).

For example, an axle408may interact with one or more bearings, whether magnetic, metal, ceramic, hybrid ceramic, etc., of the enclosure104, to allow the flywheel402to spin about an axis formed by the axle408. The enclosure104may include or couple with one or more bearings that support the flywheel402horizontally to keep it spinning with little-to-no vibration, as described below. In some cases, the bearings may be ceramic to avoid interaction with a magnetic field of a magnetic lift member152or other magnetic component.

The axle(s)408may interact with the bearing(s) to provide vertical or horizontal support to the flywheel402, for example, by keeping the axles at a defined location and balanced at a defined axis of rotation.

For instance, a bottom bearing may interact with the bottom of the flywheel402and/or a top bearing may interact with the top of the flywheel402, for example, inside the enclosure104. In some implementations, a magnetic levitation device or magnetic lift assistance member152may be used to reduce the friction or pressure, for example, on one or more of the bearings. For instance, a magnetic levitation device may be disposed at a bottom of the flywheel402to apply upward force thereon thereby limiting the force due to gravity on a bottom bearing and/or balancing force between a top and bottom bearing. In some implementations, a magnetic lift assistance member (also referred to as magnetic lift member)152may be positioned at a top of the flywheel402/enclosure104to pull the enclosure104upward, thereby decreasing the force due to gravity on a bottom bearing(s). As noted in further detail elsewhere herein, the magnetic lift assistance member152may lift less then, exactly, or greater than the weight of the flywheel402so that there is some, little, or no weight on the bottom and/or top bearing(s).

The amount of weight held by magnets of the magnetic lift assistance member152may be adjusted based on a distance from the magnets, as described elsewhere herein. For instance, the flywheel may be manually adjusted by an installer or, in some implementations, the enclosure104may include or may be coupled with one or more flywheel positioning components that may adjust the position of the flywheel402, for example, to ensure that a correct distance between the flywheel402and magnetic lift assist mechanism152, top bearing, bottom bearing, or other component of the assembly102. For instance, a flywheel positioning component may move the flywheel402(e.g., inside the enclosure104) from a shipping position to an engaged position where it is in a correct position relative to the bearing(s) to minimize bearing wear and friction.

It should be noted that although the enclosure104is illustrated as fully enclosed, including reinforcements, welds, seals/O-rings, etc., that allow a vacuum to be maintained inside the enclosure104with the flywheel402; however, it should be noted that other implementations are possible and contemplated herein, such as where the enclosure104is fully or partially open.

In some implementations, the flywheel assembly102may include various components mounted to the enclosure104(e.g., via a lid128assembly mounting plate or bracket) that support the operation of the flywheel402. For instance, the flywheel assembly102may include a supercapacitor106, motor-generator110(and associated mounting hardware), driver and CPU/controller112, vacuum pump108, various inverters, wiring harnesses, circuit breakers, and other equipment, although other implementations are possible and contemplated herein.

As illustrated in the examples ofFIGS.1A-1D, a flywheel enclosure104may be round with a flat bottom and top and various reinforcing ridges, which configuration may provide strength to the enclosure104to prevent buckling due to an internal vacuum while also preventing external damage in case of a mechanical failure of the flywheel402. It should be noted that the enclosure104may be square, hexagonal, etc. It may have rounded (e.g., as illustrated inFIG.1D) or flat sides (e.g., as illustrated inFIG.1A). As illustrated inFIG.1A, a mounting plate may be positioned on top of the enclosure104components mounted thereto, as described in further detail below.

In some implementations, as illustrated in the examples, the flywheel assembly102may include one or more (e.g.,3and4arms are illustrated) motor mount braces132that couple with a lid128of the flywheel enclosure104and extend upward to support a motor mount, which may comprise a ring that holds the motor-generator110in alignment with an axis of rotation of the flywheel402. In some instances, the motor mount braces132may include linear actuators that lift the motor-generator110vertically in order to decouple the motor-flywheel402coupling, such as the magnetic coupling118described in further detail below. The flywheel assembly102may include a component mounting plate or lid assembly mounting plate(s)130that couple with top ribs or other structures of the enclosure104and provide mounting points for the various accessory components of the flywheel assembly102. In some instances, the lid128or lid assembly mounting plate(s)130may have various perforations that allow the motor mount braces132, axles408, motor-flywheel402coupling, vacuum pump108connection and other components to pass therethrough. Accordingly, the components may be securely mounted to mounting plate130, lid128, enclosure104, or otherwise (e.g., as illustrated in the example figure) in order to speed assembly and improve stability.

As shown in the example ofFIG.1A, the enclosure104may have a plurality of reinforcing structures, such as ribs, rings, etc.

The enclosure104may also include one or more feet114or other supports that provide support to the ribs (e.g., the side or bottom ribs) or other structures (e.g., a bottom plate) of the enclosure104to secure the flywheel assembly102, support the weight of the flywheel402, and/or isolate the flywheel402's movement/vibration; although, it should be noted that vibration is ideally limited by balancing the flywheel402and acceleration, temperature, or other sensors may be located in the bearings, axles408, enclosure104, or other components.

FIG.1Billustrates an example cross section view of a flywheel assembly102. For instance, as shown in the figure, a flywheel402having a number of stacking plates122and a top and bottom axle408bis located inside an enclosure104. The bottom axle408bof the flywheel402is shown interacting with bottom bearings that support the flywheel402horizontally and/or vertically. The top axle408aof the flywheel402is shown passing through a magnetic lift member152and into a magnetic coupling118, which couples the axle408with a stator (directly or via other components, axles408, drive shafts, gears, etc.) with the motor-generator110, which is held vertically above the axle408using the motor braces132. Additionally, as noted elsewhere herein, various sensors may be located throughout the assembly, such as the RPM sensor mount116that is located adjacent to the magnetic coupling118, as well as various temperature, acceleration, etc., sensors that may be positioned adjacent to the motor110, bearings, and other components of the assembly. These and other implementations and features are described in further detail below.

FIG.1Cillustrates another example MESU102or flywheel assembly102with a different implementation of the enclosure104. As illustrated, an enclosure104may be a cylindrical enclosure with an enclosure base, such as a tub126and a lid128. The enclosure104may also include one or more feet114(e.g., three are illustrated inFIG.1C) or legs support the flywheel assembly102. A foot114may include a bushing or other component that isolates vibrations, bolt holes to bolt the flywheel assembly102to a floor or other location.

In the depicted example, the motor-generator110may be mounted higher on motor mount braces132and/or base than the example ofFIG.1A, for example, to allow access to mount or remove the motor-generator110, magnetic coupling118, bearings, or other components. Additionally, while the other components illustrated inFIG.1Aare not shown inFIG.1C, they may also be mounted to the lid128or another location of the flywheel assembly102. For instance, a vacuum pump108, supercapacitor106, chemical battery, driver, CPU, etc., may be mounted to the lid128, tub126, other portion of the flywheel assembly102, or otherwise.

FIG.1Dillustrates the example flywheel assembly102ofFIG.1Cwith the lid128and other components omitted to show an example massive flywheel402inside the enclosure104. As shown, the flywheel402may be positioned at a center of the enclosure104, although other implementations are possible. As illustrated in the example ofFIG.1D, a flywheel402may include one or more clamping plates120(the top clamping plate120ais shown), one or more stacking plates122, one or more bolts holding the clamping plates120together and/or to the stacking plates122, and one or more axles408. These and other features and implementations are described in further detail elsewhere herein.

FIGS.2A-2Fillustrate an example flywheel enclosure104and various components, views, and constructions thereof.FIG.2Aillustrates an example flywheel enclosure104with a motor mount, magnetic coupling118, and other features coupled therewith. For instance, various components, such as the motor-generator110, CPU, vacuum108, and mounting plates130are removed to expose the underlying structure. As illustrated in the example, four motor mount braces132are coupled to a top plate (e.g., part of a lid128) of an enclosure104and extend upward to provide rigid support to a motor mount base206. The motor mount base206may be round or any other shape to accommodate various components, such as the motor-generator110, magnetic coupling118, bearing(s), axle(s)408, etc. For instance, the motor mount base206may be rounded at a top to receive and mount (e.g., using fasteners, such as bolts) the motor-generator110, have a perforation through which a flywheel axle408and/or motor axle, etc., may pass, and or may allow various other components to be coupled or mounted thereto. For instance, a magnetic coupling118may be mounted to or integrated with the motor mount base206, so that it can easily be attached to the enclosure104.

As depicted in the example, the motor mount braces132and base206may be configured to be lifted above, accommodate, and/or hold other components. For instance, a motor coupling, such as the illustrated example magnetic coupling118may be coupled to a bottom side of the motor mount base206to interact with both a top axle408aand a motor-generator110. Similarly, this positioning may allow top bearing(s) to be installed or maintained under the braces/base. Similarly, as noted elsewhere herein, reinforcing components or structures of the flywheel assembly102may support the motor110, prevent undesired twisting of components, and hold a bearing and/or magnetic lift member152.

FIG.2Aalso illustrates various assembled structures of the flywheel enclosure104, which may include a lid128and a tub126. The lid128, as described in further detail below, may include a top plate, top rib(s), motor mount brace(s)132, mounting plates, and various other structures. For instance, a top ring218may include a ring of material (e.g., a steel ring or set of bends in steel plates) may be disposed surrounding an axle408a/axis of rotation to provide torsional rigidity to the enclosure104and/or to top ribs, which may radiate outward from the top ring218and provide strength to the lid128, which may support motor mount brace(s)132, mounting plate(s), a vacuum108, etc., and may prevent the top plate from buckling when force is placed thereon. The top ring218, top rib(s), top plate, and/or other structures may work together to support air pressure due to an internal vacuum and/or the weight of the flywheel402. For instance, a magnetic lift mechanism152may be coupled to the lid128(e.g., at a center near the axle408a) to lift some or all of the weight of the flywheel, so the strength of the lid128is particularly beneficial. Depending on the implementation, the lid128may be constructed of one quarter to one half inch steel plate, or a thicker construction (e.g., as in the example ofFIG.1C), which may be flat, welded together, and/or have various bends to further increase rigidity. For instance, the top ring218and top ribs may include one or more longitudinal bends to increase their strength and the ability to mount components thereto.

The enclosure tub126, as described in further detail below, may include one or more side walls that encircle the flywheel402, which may be a continuous ring of material or bent metal (e.g., steel) or other plates that are welded together. The side walls may provide vertical strength to the enclosure104while also mitigating mechanical failure of the flywheel402. Side ribs (e.g., steel plates welded to the side walls, such as the top ribs) may also be attached around the side wall, as illustrated, to provide further strength and avoid buckling inward or outward. The side ribs and/or side walls may be coupled (e.g., welded, glued, bolted, etc.) with a wall ring to which a lid128may be bolted, as described below, and with a bottom plate (which may have structures, such as bottom ribs, as described below).

For instance, a magnetic coupling118is shown in the example ofFIG.2A. The magnetic coupling118may couple the flywheel axle408(e.g.,408a) with an axle or rotor of the motor-generator110. The magnetic coupling118may be supported by a motor mount base206, top ring218, or other components of the flywheel assembly102to hold it above an axle408. The magnetic coupling118may include an external rotor bottom210and external rotor top212, which may house an internal arrangement of magnets and/or bearings, etc., as described in further detail below. The magnetic coupling118may include an internal rotor top214with a rounded machine key216that interacts with a corresponding slot in an axle and/or rotor of the motor-generator110to improve the strength of the mechanical connection between these components. A similar structure may additionally or alternatively be used with an axle408a. The magnetic coupling118is described in further detail below.

FIG.2Billustrates an example flywheel enclosure104with an upper bearing and O-ring housing or other components removed. As illustrated, a top component of the magnetic lift member152may surround the top axle408aof the flywheel402to interact with the top clamping plate120a(not visible inFIG.2B) or another component of the flywheel402. A magnetic lift member152may include a ring of magnets coupled (e.g., welded, bolted, etc.) to the top plate of the lid128, top reinforcement ring408, and/or other components of the enclosure104or flywheel assembly102. For example, the magnetic lift member152may be coupled with a bottom side of the top plate of the lid128to be in close proximity to the top clamping plate120aof the flywheel402, as described elsewhere herein.

As illustrated in the example ofFIG.2B, the lid128may include a flat plate with various ribs, rings, or other reinforcing or mounting structures coupled (e.g., integrated with, welded to, bolted to, etc.) thereto. As illustrated in the example ofFIG.2B, the top plate of the lid128may include a perforation at a center or axis of rotation, for example through which a top axle408a, portion of a top axle408a, or other components (e.g., bearings, seals, magnetic couplings118, motors110, etc.) may extend or be mounted. A magnetic lift member152may be in, below, or adjacent to the perforation.

FIG.2Cillustrates an example enclosure tub126shown from the bottom. As illustrated, a lid128has been omitted while the bolts for the lid128are shown in place in a top ring230. As described in further detail above, the enclosure tub126may include side wall(s)232, side rib(s)234, a bottom plate236, bottom rib(s)238, feet114, and other components. For instance, a bottom reinforcement ring240may be located at a center of the bottom plate236and bottom ribs238may radiate outward therefrom in order to provide strength and rigidity. The ribs and other structure illustrated, as noted with the top128, may provide support to the flywheel402, for example, via bearings, magnetic lift, and/or axle(s)408.

Four example feet114are illustrated coupled with the bottom plate236of the tub126in the example ofFIG.2C. The feet114may allow the flywheel assembly102to be bolted directly to an external structure and, in some instances, may allow some leveling of the enclosure. Example implementations of feet are114are described in further detail below.

FIG.2Calso illustrates a retaining cap242that may couple with the enclosure tub126(e.g., by bolting it to a bottom reinforcement ring240or other structure) to allow various components, such as a bottom/lower bearing assembly of the flywheel402to be accessed. The retaining cap242may also include seals/O-rings that seal the vacuum of the enclosure104. As described in further detail below, the bottom or lower bearing assembly may include one or more horizontal and/or vertical bearings, a shipment support area or ring262, a bearing height adjustment mechanism (e.g., the nut bearing holder264described below), and adjustment locking mechanism606.

For example,FIG.2Dillustrates an example enclosure tub126. As illustrated, in the example implementations, various configurations and constructions are possible. For instance, the enclosure104and its components may be made of plate metal (e.g., steel, aluminum, etc.) that is attached together to form the enclosure104. For instance, the plate metal may be coupled or bent at various angles or continuously to create side walls232, a bottom plate236, top lid128(not shown inFIG.2D), etc., and ribs (e.g.,234) positioned at a normal angle to the plates may be attached thereto to provide increased strength. The walls, ribs, top/bottom plates, and other components may be attached together using various techniques, such as welds, glue, or fasteners. For instance, where metal plates are used, they may be welded together to not only provide strength against an internal vacuum but also mitigate against mechanical failures of the flywheel402. For example, a bottom plate236may be welded to a side wall232(which may comprise one or multiple coupled segments), which may be welded to a top ring230, as shown inFIG.2D. Side234and bottom ribs238may be welded to the walls, plates, and/or reinforcing rings, as illustrated in the examples.

Other implementations of an enclosure tub126or other components are described and illustrated elsewhere herein.

In some implementations, the top ring230(and/or the lid128) may include grooves252for accepting one or more seals or O-rings, so that top ring230may be sealed against the lid128, although other implementations are possible. In some instances, multiple (e.g., two) seals/O-rings may be used to provide redundancy.

In some implementations, a side wall232may include one or more holes or perforations through which the internal cavity may be accessed, such as for adjustment, sensors, for receiving a vacuum hose or fitting, or for other purposes. These perforations may be sealed using gaskets, caps, or other components during operation of the flywheel402.

As illustrated inFIG.2D, in some implementations, the enclosure tub126may include a hole254or perforation at a bottom center at which the bottom/lower bearing assembly may be located. For instance, the hole254in the bottom of the tub126may allow the flywheel402to be adjusted, mounted, or otherwise, as described elsewhere herein. It should be noted that in other implementations, such as where a solid bottom of the enclosure104supports bearings and/or other components of the flywheel402, are possible. Similarly, in some implementations, the flywheel402may be entirely supported by a lid128of the flywheel enclosure104and the bottom of the flywheel enclosure104may be solid.

FIG.2Eillustrates an example enclosure tub126with a shipping ring262, nut bearing holder264, and bearing(s)266, which may be mounted at the hole or perforation in the bottom of the enclosure104. As described in further detail below, one or more bearings266that support the flywheel402(e.g., via a bottom/lower axle408bof the flywheel402) may be held by a nut bearing holder264, which may be vertically adjustable to move the bearings up or down. Accordingly, by adjusting the bearing holder264, the flywheel402can be moved up or down to move it between a storage position and adjust it in the enclosure104to provide an appropriate amount of force on the top and/or bottom bearings266.

For example, a shipping ring262may be located at the bottom of the enclosure tub126, so that a portion of the bottom axle408b(not shown inFIG.2E) and/or bottom clamping plate120b(e.g., a flat bottom portion thereof, as illustrated in other figures herein) may rest thereon when in a shipping position. For instance, when a nut bearing holder264is adjusted into a shipping position (e.g., completely downwards), a bottom bearing266and/or top bearing may be fully disengaged (e.g., vertically) from the flywheel402to avoid damage to the bearings during shipping, for example, where the weight of the flywheel402is supported on the shipping ring262. As described in further detail below, the bottom bearing266/bearing holder264may be adjusted to move the flywheel402(e.g., vertically upward) to engage a top and/or bottom bearing. Additionally, or alternatively (e.g., where a top bearing has a variable position), the flywheel402position may be adjusted to vary a distance to a magnet of the magnetic lift member152using the nut bearing holder264, for instance.

In some implementations, the nut bearing holder264may be un-adjustable, fixed, or omitted (e.g., replaced by another bearing holder). Additionally, or alternatively, a shipping ring262may be omitted or may be removable. For instance, a shipping ring262or other structure may be installed during assembly and then removed during installation, for example, as a flywheel402is manually adjusted by an installer.

FIG.2Ealso illustrates an angled flange268in a side wall232of the enclosure104, which may allow access to an internal cavity, such as by a sensor, vacuum assembly108, or other components of the flywheel assembly102.

FIG.2Fillustrates an example enclosure tub126with a shipping ring262and bearing(s)266, which may be mounted at the hole or perforation in the bottom of the enclosure104. In the depicted example, a nut bearing holder264may be omitted or permanent, for example, where it is not adjustable, although other implementations or combinations are possible.

In the example ofFIG.2F, a side wall232may be a circular wall, for example, with or without ribs. For instance, a thicker side wall232may be continuous or a strip welded at the ends to form the side wall232. The tub126may include a bottom plate236welded or integrated with the side wall232.

FIG.3Aillustrates an example enclosure lid128with various components attached thereto. For instance, the enclosure lid128may be placed onto an enclosure tub126(not shown inFIG.3A) to form an enclosure104, which may be vacuum sealed, depending on the implementation. As illustrated in the example, a lid128may include a top plate322with reinforcing top ribs324that extend radially from an axle408a(e.g., from a top reinforcing ring218) to an outer edge of the plate322. In some instances, the top ribs324may extend beyond the top plate322or into cuts in the top plate322. For example, the top rib(s)324may extend partially (e.g., at an end) into slots formed in the top plate322to further enhance rigidity and case manufacturability.

Other configurations of a lid128are also possible, such as the example implementation ofFIG.1C. For example, a lid128may not have reinforcing ribs mounting plates (e.g.,130) or other components, such as where the top plate322is thick enough to support the flywheel402, a magnetic lift component152, or other component. In some instances, the top plate322may include a recess or other area to accommodate, receive, or couple with the magnetic lift member152.

The lid128may also include O-rings, O-ring grooves/channels332, or other seal locations around a periphery of the top plate322, center perforation (e.g., in association with a top bearing assembly or other components), and other features for sealing the enclosure104when the lid128is attached to the enclosure tub126(e.g., by bolts around the peripheral edge). In some instances, the lid128or other components may include a hole, seal, valve, etc., through which a vacuum assembly108may be attached in order to actively establish or maintain a vacuum. For example, as noted above, a vacuum assembly108may be mounted to a lid128assembly mounting plate130or otherwise, depending on the implementation.

In some implementations, the lid128may also include a motor110mounted thereto, along with other components, such as a driver, controller/CPU112, supercapacitor106, etc. As these and other components may be previously assembled on the lid128and then placed onto the enclosure tub126(e.g., where a flywheel402is already positioned in the tub126), which may improve the speed and case of assembly.

In some implementations, the lid128may include a perforation at an axis of rotation of the flywheel for receiving a top axle408aof the flywheel402, although other implementations are possible, such as where a top axle408ainteracts with a magnetic coupling118integrated or coupled with the lid128. For instance, the magnetic coupling118may be sealed and/or placed at a center of the lid128and may interact with the top clamping plate120ato provide interaction between the flywheel402and the motor110.

In some implementations, the axle408amay pass through the perforation, which may include or be coupled with one or more bearing(s)334that support the axle408ahorizontally and/or vertically (e.g., holding the flywheel downward from contacting magnets in the magnetic lift member152). One or more magnets, such as in a magnetic lift assist member/mechanism152may be attached to the lid128.

A magnetic lift member152may extend downward from the bearing(s)334or other components to bring it into proximity with the top clamping plate120aand/or stacking plates122of the flywheel402, which may increase the efficiency of the magnets. Although the magnetic lift member152is illustrated as being a continuous ring, multiple individual magnets may be included (e.g., in a balanced manner) around the axis of rotation of the flywheel402(e.g., inside a housing of the magnetic lift member152). In some implementations, the height of the magnetic lift member152and/or its magnets may be adjustable by tightening or loosening bolts coupling the magnetic lift member152to the lid128, for example, from underneath the lid128or on top of the lid128(e.g., when the lid128is on top of the enclosure tub126). Accordingly, a position (and, by extension, strength) of the magnets may be adjustable to further balance the system and force on the bearings334.

FIG.3Billustrates an example vacuum assembly108that may actively maintain or initially established a vacuum in the enclosure104(e.g., via a perforation in the lid128or tub126). The vacuum assembly108may be mounted to the enclosure104, as illustrated inFIG.1A, and it may be triggered using a pressure sensor that senses pressure inside the enclosure104. The vacuum assembly108may include a vacuum pump352that is powered by the flywheel402itself, supercapacitor106, a chemical battery, or grid power. The vacuum pump352may be coupled with a motorized on/off valve354that opens or closes the vacuum to avoid leakage, a solenoid valve356and solenoid valve coil housing358that may allow air to enter the enclosure104, desiccant filter360that prevents dust or debris from entering the enclosure104while also reducing buildup of moisture (e.g., due to the operation of the vacuum pump352), and other components that maintain the vacuum and limit humidity in the system.

The vacuum assembly108may include additional, fewer, or different components. It may be used to reduce a pressure and therefore an air resistance of a spinning flywheel402. In some implementations, when a technician is performing maintenance or repairs on the flywheel assembly102, the vacuum may be released (e.g., where air enters the enclosure104through a filter) to allow the maintenance to be performed. In some implementations, the vacuum pump352may create a positive pressure inside the flywheel enclosure104. By providing a positive pressure, dust or other debris may be prevented from entering the enclosure104, for example, because it may be difficult to clean out.

FIG.3Cillustrates an example foot114of a flywheel enclosure104. The foot114may include a top portion374that may be welded, bolted, or otherwise affixed to a bottom (e.g., a bottom plate236and/or rib238) or side (e.g., side wall232or rib234) of the enclosure104. The foot114may also include a coupling portion376that allows it to be bolted to an external surface, such as a cement pad. In some implementations, the foot114may also include adjustable bolts378to allow the flywheel enclosure104to be leveled or bushings that isolate vibrations.

FIG.3Dillustrates an example foot114of a flywheel enclosure104. The foot114may include a top portion374that may be welded, bolted, or otherwise affixed to a bottom (e.g., a bottom plate236and/or rib238) or side (e.g., side wall232or rib234) of the enclosure104. For example, the top portion374may include a bolt that bolts to a leg coupled with the enclosure104(e.g., as inFIG.1C). The foot114may also include a coupling portion376that allows it to be bolted to an external surface, such as a cement pad. In some implementations, the foot114may also include a rubber bushing380, gasket, etc., that isolates the flywheel enclosure104from a floor.

FIGS.4A-4Dillustrate an example flywheel402and various components, views, and constructions thereof. There are a number of innovative features in the flywheel402. For example, the flywheel402may include flywheel plates (120and/or122) that are coupled together using friction, which may be performed in addition to or in lieu of other connections, such as adhesive, welding, or otherwise. Some implementations of the flywheel402include bolts through components while others do not include bolts through components. Similarly, some implementations of the flywheel402include two separate axles408—a top axle408aand a bottom axle408b. For instance, while previous flywheels402may include bolts attaching each of their components together, some implementations of the flywheel402herein may separate the axle408and/or use a clamping force from clamping plates120(and/or axles408) to increase friction between the stacking plates122themselves, which may improve manufacturing and reduce points of failure when the flywheel402is spinning at high speeds.

In some implementations, clamping plates120may be used on the top and bottom of the flywheel402to support the flywheel402, for example, by coupling the stacking flywheel plates122together and/or to axles408. A top clamping plate120aand a bottom clamping plate120bmay be drawn together by bolts at or near its peripheral edge, as described in elsewhere herein, which applies pressure inward on the stacking plates122in an axial direction thereby increasing friction. The friction may also allow rotational force to be transferred through the stacking plates122while also preventing them from moving out of alignment, which may throw the balance of the flywheel402off.

Depending on the implementation, the clamping force from the clamping plates120may be applied to the stacking plates122directly (e.g., by direct contact between the clamping plates120or stacking plates122) and/or via other components, such as a portion of an axle408or other contact points (e.g., bushings or washers, as described below). For example, a clamping plate120may apply force to a center of the stacking plates122via a top and bottom axle408b(and/or washer(s), ball washer(s), bushings at a peripheral edge or arm end, and/or otherwise).

In some implementations, the clamping plates120may be less massive than the stacking plates122(although other implementations are possible, as noted herein), so each type of plate may expand (and, potentially, become thinner) differently, especially at the peripheral edge. Accordingly, in some instances, bushings or other components may allow the stacking plates122to move relative to the clamping plates120while the clamping force is continuously applied.

The clamping plates120may have various contours and configurations to allow them to provide clamping force and other functionality. In some implementations, the stacking plates122may be configured differently from the clamping plates120and their function is primarily to add rotational mass to the flywheel402in order to store energy. The stacking plates122may be massive plates that are substantially round or may include various contours based on interaction with the clamping plates120or an assembly fixture. Example stacking plates122and clamping plates120are described in further detail below.

As described in further detail elsewhere herein, shapes, configurations, or features of the clamping plate(s)120may be designed to improve their interaction with the magnetic lift member152, for example, to improve an amount of space, a magnetic pull, or otherwise. In some instances, it may further be configured to reduce eddy currents caused by the magnetic lift member152.

FIG.4Aillustrates a side-bottom view of the example flywheel402. As illustrated, a plurality of stacking plates122may be continuously stacked with their faces touching each other to minimize space consumed and flex while increasing friction. Fourteen stacking plates122are illustrated, although other implementations are possible and contemplated herein. As illustrated, there may be a space442between one or both of the clamping plates120and the stacking plates122. Although this space442is illustrated as being relatively large and uniform, it may be smaller or non-existent for one or both of the axles408. For instance, the top clamping plate120amay contact a top-most stacking plate122, while there may be only a few millimeters between the bottom clamping plate120band the bottom-most stacking plate122, which space may vary based on clamping force applied and flex of the clamping plate120.

As illustrated in the example flywheel402ofFIGS.4A-4D, a bottom axle408bmay be coupled with a bottom clamping plate120b. The bottom clamping plate120bthen interacts with a bottom flywheel stacking plate122(e.g., via bushings, an axle washer432washer432b, a portion of the axle408, etc.). Various quantities of stacking flywheel plates may be stacked together depending on desired energy capacity, as noted elsewhere herein. Similarly, a top clamping plate120amay interact with a top-most flywheel stacking plate122(e.g., via bushings, axle washer432washer432a, etc.). The top clamping plate120amay be coupled with a top axle408a. In other implementations, a bottom face of the top clamping plate120amay rest directly against the top face of the top-most stacking plate122.

In some implementations, each of the stacking plates122may be identical, and each of the clamping plates120may be identical, although other implementations (e.g., sizes, configurations, etc.) are possible and contemplated, as noted below. Similarly, the top and bottom axle408bmay be the same or different (e.g., having a different length, interacting with different bearings or configurations, as illustrated herein.

As illustrated, when assembled, the clamping plates120of the flywheel402may align with the stacking plates122. In some implementations, a clamping plate120may have a star shape (e.g., as illustrated inFIG.4A) where the tip of each arm or branch of the clamping plate120has a bolt hole that receives a bolt for clamping the clamping plates120together. In some implementations, a clamping plate120may have another shape (e.g., as illustrated inFIGS.4C and4D) including one or more perforations proximate to a peripheral edge.

Similarly, the configuration of the stacking plates122may be based on the shape (e.g., the position and quantity of branches of the clamping plate120), as described in further detail below. For instance, bolt points of the stacking plates122may correspond to bolt points of the clamping plates120whether or not the stacking plates122contact the bolts.

FIG.4Billustrates a cross sectional view of an example multi-part flywheel402. As illustrated in the example implementation, a top clamping plate120amay be connected with a top axle408a. For instance, a top axle408amay pass through the top clamping plate120aso that the top clamping plate120amay apply downward force on the axle408. In some implementations, the axle408may include multiple parts, such as an axle408portion and an axle washer432aor432b, where the washer432(or a bottom portion of the top axle408a) contacts a top-most stacking plate122. Accordingly, via the axle408, the top clamping plate120amay apply force to the stacking plate(s)122. It should be noted that other configurations, such as direct contact or contact through another device are possible without departing from the scope of this disclosure. Accordingly, the clamping plate120may apply pressure at a center of the stacking plate(s)122via the washer and/or axle408.

Similar to the description of the top axle408aabove, a bottom axle408bmay be coupled to a bottom clamping plate120band may apply force to a bottom-most stacking plate122. It should be noted that other configurations are possible, such as where the contact is direct, where the axles408are integrated with the clamping plates120, where the axles408are integrated with one or more stacking plates122, or otherwise.

Additionally, as described in further detail below, force may be applied (e.g., in an axial direction) to a center, periphery, and/or other area of the stacking plate(s)122. For example, bolts may be tightened down on the clamping plate(s)120, which apply force to an outer edge of the stacking plates122. The force may be applied via direct contact between the clamping plates120and the stacking plates122or via an intermediary device, such as a bushing or washer (e.g., a ball washer or axle washer432). In some instances, the clamping plates120may flex between the axle(s)408and the bolt(s) to provide the pressure. Accordingly, friction can be increased between the stacking plates122. In some implementations, the stacking plates122may be simple, solid plates rather than having perforations for fasteners in the plates, which may reduce strength and introduce stress risers due to centrifugal force, and which may lead to increased complexity and failure modes. In other implementations, the stacking plates122may have perforations through which bolts may pass, which may increase a radius of the plates, provide simplicity in manufacturing, or increase an inter-plate (e.g., due to friction) force.

As described below, the bolts may be tensioned to varying levels of tension to cause the friction force. Although different configurations are possible and contemplated, as noted elsewhere herein, the flywheel402may include 8 bolts located around or proximate to a peripheral edge. Each bolt may be tightened to provide a defined torque or based on an applied force before the bolts are torqued (e.g., to apply a force of 2600 pounds per bolt), which may cumulatively provide a relatively even clamping and friction force across the stacking plates122(e.g., 16,000-21,000 pounds of clamping force).

In addition to their roles in clamping together the clamping plates120, the bolts may include other features, such as the ability to mitigate failure of one or more stacking plates122(e.g., by catching a stacking plate122or portion thereof that slips or breaks). In some instances, the bolts may be replaced with other bolts of varying weights to assist in balancing the flywheel402. Other details and implementations are possible and/or described elsewhere herein.

It should also be noted that the top axle408aand the bottom axle408bshould be aligned as perfectly as possible to reduce vibrations and improve alignment with bearings, etc. Although other implementations are possible, ball washers (e.g.,232) may be used with the axles408to allow some adjustability during assembly to improve alignment. It should be noted that flat washers or no washers (e.g., the axles408may be single components instead of broken into an axle body and axle washer432) may be used.

As the axles408or axle washers432contact the stacking plates122, the application of clamping force by the bolts may cause one or more of the clamping plates120(e.g., the arms thereof) of the bend slightly and increase the force at the center that is applied by the axles408/axle washers432. Depending on the implementation, the thickness of the axle washer432(or similar component) and the configuration of the clamping arms may be such that the distance between the ends of the arms (e.g., to the stacking plates122) may be minimalized when the plates are clamped. In some implementations, in addition or alternative to the clamping force at the center of the stacking plates122, the clamping plates120may apply clamping force along a peripheral edge of the stacking plates122.

FIG.4Cillustrates a side-top view of another example flywheel402, according to some implementations. In the example ofFIG.4C, the shape of the clamping plates120has an X shape with two bolt holes proximate to the radial edge of each arm thereof. In the depicted example, the bolts may be angled as they pass from the top clamping plate120a, through the stacking plates122, and to the bottom clamping plate120b. By angling the bolts, rotational forces across the clamping plates120, stacking plates122, and axles408may be reinforced, which reduces the odds that the plates will move out of alignment when the flywheel402is spun up or down though the axle(s)408.

In the depicted example, the bolts may be angled toward each other or away from each other on alternating clamping plate arms, which improves uniformity of force (e.g., circumferentially and axially) and rotational balance. For instance, in a first arm, the bolts are angled away from each other at the top plate, while, at a second arm 90 degrees from the first arm, the bolts are angled toward each other at the top plate, which pattern may repeat, as illustrated. Where the top clamping plate120aand the bottom clamping plate120bare the same, they may be rotated 90 degrees, so that the holes on each match the angles of the bolts. For example, a bolt may be perpendicular to a radial direction of the flywheel402and angled around the periphery, for example, at an angle to the axial direction of the flywheel402.

In the depicted example ofFIG.4C, the bolts extend through the top and bottom clamping plates120band through perforations in the stacking plates122. In the example implementation where the bolts are angled, the bolts may use wedge shaped washers that allow the force from the bolts to be applied to the clamping plates120. In some implementations whether with angled or straight (e.g., axial) bolts, the bolts and associated nuts may be tapered to allow them to extend partially into countersunk holes in the clamping plate(s)120.

In the depicted example ofFIG.4C, the top clamping plate120a(and potentially the bottom clamping plate120b) may be substantially flat on its top and bottom surfaces, which allows the it to contact the stacking plates122and/or interact with a magnetic lifting component152. For example, a very flat top surface of the top clamping plate120athat interacts with a magnetic lifting component may reduce eddy currents in the top clamping plates120acaused by rotation relative to the magnetic lifting member152.

FIG.4Dillustrates a side-top view of another example flywheel402, according to some implementations. In the depicted example, the bolts extend axially through perforations422in the top clamping plate120a, the stacking plates122, and the bottom clamping plate120b. Depending on the implementation, the stacking plates122may have an equal quantity of perforations422as the quantity of bolts clamping the clamping plates120, the clamping plate(s)120may include additional perforations422proximate to their peripheral edge(s). These additional perforations422may be used in balancing the flywheel402, for instance, by drilling out the holes or adding plugs to the holes. As noted elsewhere herein, there may be a space between one or both of the clamping plates120and the stacking plates122. For instance, the top clamping plate120aand top stacking plate122may lack a space (e.g., as at442), which may prevent the top clamping plate120afrom flexing, thereby improving its flatness and interaction with a magnetic lift member. In some implementations, there may be a small gap/space between the bottom clamping plate120band a bottom-most stacking plate122, which allows some flex in clamping (e.g., to increase a force at the center/axles408). For instance, a portion of the bottom axle408band/or an axle washer (whether a ball washer or flat) may be used to provide a space between a center of the bottom clamping plate120band the bottom-most stacking plate122.

In some implementations, the stacking plates122may include contours or scallops410around a peripheral edge, which may reduce failure points due to radial stress around bolt holes and/or assist with aligning the plates. For instance, a scallop410may be a scalloped shape or contour removed or omitted from a peripheral edge of a stacking plate122.

The clamping plates120may be constructed from aluminum, steel, or another material. For instance, the plates120may be constructed from a ferromagnetic steel (e.g., AR500 steel plate) and may be stamped, formed, or machined into the desired shapes. Example masses of the clamping plates120may be 66-68 pounds when constructed from steel, although other implementations are possible.

FIG.4Eillustrates example flywheel axles408aand408b. Although other sizes and configurations are possible,FIG.4Eillustrates a top and bottom axle408bwith axle washers432(e.g., ball washers). Depending on the implementation, the top and bottom axles408bmay be identical or have variations, such as their length, whether or not they include washers or axle washers432, whether they include a motor connection466. Some features of the axle408are described in reference to a single one of the top and bottom axle408b, but they may be present on both or the other axle408.

Depending on the implementation, an axle408may include a smooth shaft464(e.g., a 50-70 mm diameter shaft464) portion that interacts horizontally with one or more bearings to keep the flywheel402aligned. The shaft464may contact one or more seals to maintain the vacuum and may be polished to avoid friction with the seals.

An axle408may include one or more bearing shelf(ves)/step(s)468that interact with bearings to provide vertical support to the flywheel402(e.g., to lift, lower, or hold it vertically).

In some implementations, an axle408may include one or more clamping shelf (ves)/step(s)470that interact with a clamping plate120. For instance, the clamping step470could be a wider area than the shaft464so that the clamping plate120applies pressure on the clamping step470to hold the axle408. In some implementations, the axle408extends beyond the clamping step470and flywheel step468, so that the axle408applies pressure to a stacking plate122, as noted above. The contact with a stacking plate122may be via a washer, such as an axle washer432(which may be a flat or ball washer). The clamping step470may interact with an edge or corresponding step(s) on a clamping plate120.

In some implementations, the clamping step470, an axle washer432, or another part of the axle408may be shaped to interact with a corresponding shape or structure in a clamping plate120. For instance, it may include a flat side, oval shape, protrusion, or other structure that allows torque to be transferred between the axle408and the clamping plate120and/or stacking plates122(e.g., where a top or bottom stacking plate122includes a shape to match this structure). For example, as noted in further detail above, an oval or small flat side may be used to avoid stress risers in the material (e.g., of the clamping plate120).

In some implementations, one or both of the axles408may include a motor connection466that may be a portion or extension of the shaft464. The motor connection466may include a flat, oval, D-shaped, or other structure/shape (e.g., a key or slot) that allows torque to be transferred between the axle408and another structure, such as a motor-generator110(e.g., via a magnetic coupling118, as described elsewhere herein). The motor connection466may additionally or alternatively include keys or other protrusions that improve the connection between the axle408and another structure (e.g., the magnetic coupling118, motor-generator110, etc.).

Although a ball washer (at232) is illustrated on both the top and bottom axle408aand408binFIG.4E, other implementations are possible and contemplated. For example, a ball washer may be used to provide a small amount of adjustability to the axle408alignment when top axle408a, bottom axle408b, stacking plates122, and clamping plates120are aligned. As illustrated in the example, two axles408may be used where the axles408are physically disconnected from each other.

In some implementations, a ball washer may be flat on its bottom where it contacts a stacking plate122while it is rounded on a top where it contacts a corresponding curve in the axle body. Accordingly, the position of the axles408could be shifted slightly during assembly to allow the axles408to be positioned. As illustrated, in some implementations, a bolt may couple the axle washer432to the axle body in order to hold it in place during assembly.

It should be noted that, in some implementations, flat washers or no washers are used with an axle408.

FIG.5Aillustrates a cross-sectional view of an example upper axle408adisposed within an upper bearing assembly of a flywheel enclosure104. In the illustrated example, some components may be omitted for visibility. As illustrated, a top axle408amay interact with a plurality of bearings334and/or seals (e.g., in a housing522) to provide vertical and/or horizontal support. For instance, multiple (e.g.,2) bearings334may be used on an axle408to increase redundancy and safety. In some instances, a temperature sensor504or accelerometer may be located in or adjacent to the bearing housing522, which allows the flywheel402to detect a failure of one or more bearings334thereby increasing a safety margin. Other features, such as cooling loops (e.g., through which coolant may be circulated), vacuum connections, etc., may also be used.

As illustrated, one or multiple seals may be located in or adjacent to the shaft of the axle. For instance, the seals may be housed within a bearing/O-ring housing522and contact the smooth sides of the axle shaft to seal a vacuum. In some instances, where the vacuum is actively established or maintained, the seals may change their shape by flexing inward to improve the seal. Similarly, the seals may be multiplied (e.g., doubled) for redundancy. Other structures, such as retaining clips may be located on one or both sides of the bearings334, so that they can be installed or replaced separately or with a housing522.

In some implementations, the bearings and/or seals/shaft may be lubricated, for example, using a high durability and/or vacuum specific lubricant. In some implementations, a special material may be used for the seals to allow them to be used in a vacuum and/or without a separate lubricant. Depending on the implementation, the bearings may be dry bearings, such as a ceramic hybrid bearing, which beneficially reduces eddy currents and other issues due to moving in a magnetic field. Additionally, or alternatively, a dry film lubricant may be used for these components.

In some implementations, as illustrated, an example magnetic lift member152may interact with (e.g., to attract) a flywheel402, such as a top clamping plate120a(and/or stacking plates122). For instance, as illustrated, the magnet(s) of a magnetic lift member152may be located above, below, or next to the center of the axle408a. For example, the magnets may be positioned by the magnetic lift member152(also referred to as the magnetic lift assist member/mechanism152) to closely interact with the flat area (e.g.,444) of the top clamping plate120a. For instance, the top bearing334may hold the top clamping plate120a/flywheel402at a defined distance from the magnetic lift member152, so that a defined magnetic force is applied, which lifts the flywheel402wholly or partially. For instance, as described elsewhere herein, the magnetic lift may be less than (e.g., so that weight remains on a bottom bearing), equal to (e.g., so that weight is roughly balanced between the top and bottom bearings), or greater than (e.g., so that the top bearing is holding the flywheel402from being pulled closer to the magnet(s)) the weight of the flywheel402at the set distance.

As illustrated and described in further detail below, the magnetic lift member152may be positioned close to the clamping plate120a, which may be ferromagnetic (e.g., a magnetic steel) flat (or matching the shape of the magnetic lift member) shape. As shown, the flywheel402may be positioned at a center of the enclosure104, although other implementations are possible. As noted elsewhere herein, the magnets of the magnetic lift mechanism152/member may be stationary and coupled with the enclosure because magnets tend to be made out of weaker material that would not hold up well to rapid spinning (e.g., because rare-earth magnets, for instance, are mechanically weak). In the depicted example inFIG.5A, a cavity is shown in the magnetic lift member152, but this cavity may include one or more magnets, as described below. The magnetic lift member152may be assembled as a unit and then bolted or otherwise attached to a lid128of the flywheel assembly102.

In the depicted example, an upper axle408amay be coupled to a motor directly or via a magnetic coupling118, as described elsewhere herein.

FIG.5Billustrates a cross-sectional view of an example lower axle408bdisposed within a lower bearing assembly524of a flywheel enclosure104. In the illustrated example, some components may be omitted for visibility. Similar toFIG.5A, as illustrated, a bottom axle408bmay interact with a plurality of bearings266and/or seals or structures to provide vertical and/or horizontal support. For instance, multiple (e.g.,2) bearing assemblies may be used on an axle408bto increase redundancy and safety. In some instances, a temperature sensor or accelerometer may be located in or adjacent to the bearing housing524, which allows the flywheel402to detect a failure of a bearing thereby increasing a safety margin, improving efficiency, etc. Stacking plates122are also shown.

As shown in the example ofFIG.5B, a cap242is also shown. The cap242may seal (e.g., using gaskets and bolts) an interior cavity of the enclosure104. The cap242may provide access to move the flywheel402within the enclosure104; install, maintain, or adjust bearings266and seals; and perform other actions.

In some implementations, the cap242and/or another component may be threaded, so that it may be twisted up/down, which adjusts the position of the bearings266and/or seals; or it may lift the flywheel402itself to set its position in the enclosure104. In other implementations, the flywheel402may be manually adjusted (e.g., to be at a defined distance from the magnetic lift member152) and then the bearings inserted or locked in position.

FIG.5Cillustrates an example flywheel402coupled with a portion of a magnetic lift member152and a lower bearing assembly outside of a flywheel enclosure104, for example, for purposes of illustration.

As illustrated in the example ofFIG.5C, an exterior of the magnetic lift member152has been omitted to show magnets532, which may be wedge magnets, and an example relative proximity to the top clamping plate120a. For instance, the wedge magnets532may, when in an active configuration, pull on the flat area (e.g.,444) of the clamping plate120a, although other implementations are possible and contemplated. It should be noted that although the magnets532and other components of the magnetic lift member152are illustrated floating above the top clamping plate120a(e.g., instead of attached to an enclosure104/lid128) for purposes of illustration.

The example ofFIG.5Calso illustrates a lower bearing assembly524that holds one or more bearings at the bottom of the flywheel enclosure104. For instance, a lower bearing assembly524may be welded, integrated with, or bolted to an enclosure tub126. The lower bearing524may support none, a portion, or all of the weight of the flywheel402. In some implementations, the lower bearing524may merely be present to keep the flywheel402horizontally aligned.

The lower bearing524may include a shipping support area262, such as a shipping ring, on which the weight of the flywheel402may rest during shipping, storage, or when not in use. The shipping support area262may be any device that may support the flywheel402, such as a plastic or metal ring in the enclosure tub126.

The height and/or relative positioning of the bearings may also be adjusted because a quantity (e.g., 10, 14, 18, 28, or other quantities) of stacking plates122may vary, and thicknesses of each plate may vary (e.g., by a thousandth of an inch), the overall thickness of the flywheel402may vary enough to affect the functioning or longevity of the bearings unless there is flexibility in the design, as illustrated, to accommodate different heights.

As described elsewhere herein, a retaining cap242or another mechanism may seal the enclosure and/or capture an adjustment nut so that it does not accidentally move in order to lock the Z/vertical axis of the flywheel402.

FIGS.6A-7Hillustrate various views, components, and constructions of an example flywheel positioning system. The flywheel positioning system may be configured to position the flywheel402within the enclosure104, as described elsewhere herein. Although a certain implementation is described, other implementations and features are contemplated, and the provided examples should be understood as examples.

In some implementations, the flywheel positioning system may adjust the position of the flywheel402between the top and bottom bearings266so that a distance between the bearings266may be adjusted to match a size of the flywheel402and thereby to minimize wear on the bearings266while using their functionality. For instance, as noted elsewhere herein, the flywheel positioning system may lift the bottom bearing266upward, in turn lifting the flywheel402upward, until the flywheel402contacts the top bearing and/or is correctly distanced from the magnetic lift member/mechanism. In some implementations, as the flywheel402is lifted up, it may contact a surface, such as a top bearing (e.g., at the top of an enclosure104, magnetic lift member152, or bumper. Once it contacts the surface, it may be backed down by a defined amount to correctly position the flywheel402. In some implementations, the positioning system (e.g., a nut bearing holder264) may include one or more marks that may be used to determine correct positioning.

In some implementations, the flywheel positioning system may be used to move the flywheel402or components of the flywheel assembly102between modes. As noted above, the flywheel positioning system may move the flywheel402(e.g., via a bottom bearing266) or a shipping surface/ring262in order to move the flywheel402between a shipping position and an active position.

For example, as noted in further detail elsewhere herein, a flywheel402may rest on a shipping ring262during shipping or storage. The flywheel positioning system may be adjusted to lift the flywheel402off the shipping ring262and into an active position, for instance, by engaging a bottom bearing266(e.g., by moving the bearing266and/or flywheel402) and/or the top bearing (e.g., by moving the bearing and/or flywheel402).

FIG.6Aillustrates a cross sectional view of an example flywheel positioning system, which may include a retaining cap604that couples with a positioning nut/nut bearing holder264and a flywheel enclosure104. For example, the base ring240may be integrated or coupled with a bottom plate236of the enclosure104tub. One or more bottom ribs238may also be coupled with the bottom plate236and base ring240(e.g., by a weld), which provides strength to the enclosure104sufficient to hold the weight of the flywheel402.

In some implementations, the base ring240may be threaded on its interior to interact with a nut bearing holder264, as described below. In some implementations, a retaining cap604may be coupled with the base ring240via one or more bolts, which bolts may provide adjustability to the rotation of the retaining cap604on the enclosure104, as noted below.

In the depicted examples, a flywheel402and flywheel axle408bare shown inside an enclosure104. Although the flywheel positioning system could be used with a top axle408b/the top of a flywheel, the illustrated examples ofFIG.7Billustrates the flywheel positioning system used with a bottom axle408bof the flywheel402.

As shown, an axle408bmay interact with one or multiple bearings266held by a lower bearing holder264. The lower bearing holder264may be a nut bearing holder264where the nut includes a bearing266holding portion, a tightening portion, and one or more threads, as described below. The bearing(s)266may support the axle408bof the flywheel. In some instances, the bearing(s)266and/or nut bearing holder264may be held by a lower sleeve608.

As illustrated in the example, the nut bearing holder264may hold the bearings266and may rotate (e.g., using threads) within a lower ring of the enclosure104tub to move the nut bearing holder264and bearing(s)266upward or downward relative to the enclosure104, which may, in turn, move the flywheel upward or downward. For example, when in a shipping configuration, the nut bearing holder264, bearing(s)266, and flywheel402may be moved downward so that the bottom surface of the clamping plate120brests on the shipping ring262, which may be a metal, plastic, or another material on which the flywheel may rest to remove stress from the bearing(s)266. In some instances, the flywheel402may rest directly on the bottom of the enclosure104tub when in a shipping or storage position.

Although other implementations are possible, a nut locking mechanism may include one or more of a cap604, a hex lock606, and/or a nut bearing holder264, etc. In some implementations, as described in further detail below, a cap hex lock606may include various protrusions, recesses, or other structures, such as teeth714(e.g., defining a set of angles at which a nut may be held), that interact with the nut bearing holder264to prevent the nut bearing holder264from twisting relative to the enclosure104, which may change the vertical position of the flywheel in the enclosure104. The cap604hex lock606is described in further detail below.

In the depicted implementation, a retaining cap604is also shown. The retaining cap may be an implementation of a cap242. The retaining cap604may include one or more O-rings752or channels to seal the vacuum internal to the enclosure104. Accordingly, when the retaining cap604is placed onto the enclosure104(e.g., after flywheel positioning), a vacuum may be maintained.

In some implementations, the retaining cap604may hold the cap hex lock606in position on the nut bearing holder264, so that the nut bearing holder264cannot rotate when the retaining cap604is bolted to the enclosure104(e.g., the base ring240). For example, when attaching the retaining cap604, it may be rotated to mate up with the cap hex lock606to hold it in a specific position, causing the cap hex lock606to bridge the space between the nut bearing holder264and the retaining cap604and prevent the nut from rotating. It should be noted that although the cap hex lock606is described as a separate device from the retaining cap604, it may be integrated with either the nut bearing holder264or the retaining cap604to simplify installation. Example implementations of the nut bearing holder264, cap hex lock606, and retaining cap604are described elsewhere in further detail below.

Accordingly, as an example procedure for changing the mode of the flywheel from a shipping position to an active position, a technician may rotate the nut bearing holder264, so that it moves upward and lifts the flywheel internal to the enclosure104and off of the shipping ring262. Once the flywheel402(e.g., a top clamping plate120a) contacts a surface at the top of the enclosure104, magnetic lift member152, top bearing(s)266, bumper, or other component, the technician may stop rotating the cap604hex lock606upward and may back it off slightly to relieve pressure on the top bearing266or contact with another component. The technician may then insert a cap hex lock606around the hex head of the nut bearing holder264to mesh the teeth714of the lock with the nut. The technician may then place the retaining cap604onto the base ring240and rotate it until it interacts with the cap hex lock606(as described below) to hold the cap hex lock606in a given orientation so that it does not rotate. The technician may then tighten bolts between the retaining cap604and the base ring240to seal the enclosure104and lock the nut bearing holder264in place.

Accordingly, the position of the flywheel402and lower bearing266may be adjusted to accommodate for shipping, variations in flywheel thickness, or other aspects. By locking in an adjustable vertical position of the flywheel402, the flywheel positioning system prevents unintended movement of the nut bearing holder264during flywheel rotation or vibration. It also allows the position to be adjusted in the future for troubleshooting or maintenance, where adhesives or welds would not allow such access. Accordingly, the lock is secure, sealed, and accessible.

Although not visible inFIG.6A, one or more sensors756aand756bmay also be located in the lower bearing assembly, such as in the base ring, adjacent to the bearings266, in the retaining cap604, or otherwise. The sensors756may measure vibration, temperature, rotational velocity, or otherwise.

FIG.6Billustrates a bottom plate236of a flywheel enclosure104with a lower bearing266assembly coupled thereto. In the illustrated example, the enclosure104slides, flywheel402, and bottom axle408bhave been omitted.

As illustrated, the shipping ring262and bolt plate754may be a single component or multiple components, one of which is slightly raised above the bottom plate236of the enclosure104. The top of the bolt plate754may act as a shipping ring262/support surface, as described above, to support the flywheel402when not in use. The bolt plate754may also couple together with the base ring240, lower sleeve608, and/or other components of the assembly102to hold it together and provide support.

In some implementations, the nut bearing holder264may be positioned within the base ring240and shipping ring262/bolt plate754and move upwards and downward therein in order to move the bearing(s)266. The bearings266may move upward and/or downward with the nut bearing holder264, for example, to lift or lower the lower/bottom axle408band change the position of the flywheel402, as described above.

FIG.6Cillustrates a side view of an example lower bearing266assembly with a bottom axle408band bottom clamping plate120bcoupled thereto. The lower bearing266assembly is shown coupled with a bottom plate236of a flywheel enclosure104and the enclosure104sides are omitted. As illustrated, the bottom axle408bof the flywheel402extends into the nut bearing holder264to interact with the bearings266held thereby. The example implementation ofFIG.6Bcorresponds to an active position where the flywheel402(e.g., the clamping plate120b) is lifted off the shipping ring262.

FIG.7Aillustrates a bottom-up view of an example nut bearing holder264coupled with a flywheel enclosure104and a hex lock606. As illustrated in the example ofFIG.7A, a nut bearing holder264is located in a base ring240and a retaining cap604is removed for visibility. As illustrated, the nut bearing holder264may be in a defined rotation that affects the height of the flywheel402. Because small changes in the height of the flywheel402may affect its functioning (e.g., while it interacts with a magnetic lift member152or bearing(s)266), a few degrees of rotation of the nut bearing holder264can significantly affect the longevity, etc., of the bearings266. Accordingly, the hex lock606may include teeth714on a radially inward edge, any of which may interact with the sides of the nut bearing holder264in various rotational positions. As noted below, the hex lock606may interact with a retaining cap604to hold the hex lock606in place, so that the hex lock606bridges the gap and/or rotational difference between the nut bearing holder264and the retaining cap604. Accordingly, when the retaining cap604is placed on it, the cap604and hex lock606combination captures the torque of the nut bearing holder264, which may be otherwise disposed to rotate due to the rotation of the flywheels402and bearings266.

Also, as illustrated inFIG.7A, the nut bearing holder264may include a hex shape to interact with wrench or other tools of various sizes, although it may be a different shape to accommodate different tools. In some implementations, it may include one or more slots at the bottom, so that a flat tool or a rod can be used to tighten or loosen the nut.

FIG.7Billustrates an example cap604or nut hex lock606(also referred to as a hex lock606). As illustrated in the example ofFIG.7B, the hex lock606may be a ring that may extend around a hex nut, such as the nut bearing holder264; although, it should be noted that it may extend only partially around the nut. The hex lock606may be a plate or disk of material that is formed, machined, or stamped (e.g., from steel) to have its features, as noted below.

In the depicted implementation, the hex lock606may include teeth714or other grooves, protrusions, recesses or other structures disposed around an inner edge of the ring. For instance, the angles of the teeth714may match the angle of the hex lock606(e.g., 120 degrees) and where the radius of the nut bearing holder264matches the radius of the corners of the teeth714, so that when the hex lock606is placed on the nut, the teeth714hold the nut.

The quantity of teeth714of the hex lock606may be varied depending on the increments of angles at which the nut may be held and adjustability of the retaining cap604. For instance, the teeth714may be larger and therefore fewer if the precise angle of adjustment of the nut is less important but smaller and greater in number of more precision is required for the application. Similarly, as noted elsewhere herein, the retention cap604may provide adjustability in its mounting to the enclosure104and/or interaction with the hex lock606, so the teeth714may be made larger based on the retaining cap604adjustability.

The hex lock606may also include one or more protrusions712at an outer edge of the ring (e.g., a full or partial ring) that may interact with another structure to prevent the hex lock606from rotating. For instance, the hex lock606protrusions712may interact with corresponding protrusions or recesses of the retaining cap604, as noted below, to hold the hex lock606in a position. The hex lock606may include various quantities of protrusions, such as the six pairs of protrusions illustrated in the example. The protrusions and their interaction with one or multiple positions and structures are described in further detail below.

It should be noted that, although nut interaction teeth714are illustrated in the inner edge of the ring and hex lock protrusions712are illustrated on the outside of the ring, other implementations are possible and contemplated herein. For instance, the hex lock606and/or retainer cap604may interact with an inner surface of the nut bearing holder264to keep it in place.

As noted below, in some implementations, the structure of the hex lock606, such as the teeth714, may be integrated with the retaining cap604.

FIG.7Cillustrates a top view of an example retaining cap604. As illustrated, the retaining cap604may include hex lock interaction elements728. For instance, the interaction elements728may be raised above the body of the retaining cap604in order to extend upward into the space next to a nut bearing holder264and interact with the hex lock606. For instance, the retaining cap604may include an equal or fewer number of hex lock interaction elements728as the hex lock606includes locking protrusions712, so that these components interact with each other in order to rotationally couple the hex lock606to the retaining cap604. As illustrated in the example, the hex lock606may include more locking protrusion712pairs than the retaining cap604includes interaction elements (e.g., a 2:1 ratio), so that the hex lock606can be locked into multiple positions relative to the retaining cap604. In some instances, these positions may be offset at various angles to provide further adjustability to the interaction.

In some implementations, the retaining cap604may include raised areas726that contact the bottom of the hex lock606to hold it in place. For instance, the top of the hex lock606may press against another area of the nut bearing holder264, base ring240, or another area to keep it from falling off the hex lock interaction elements728.

In some implementations, the retaining cap604and/or base ring240(not shown inFIG.7C) may include recesses or other areas that may hold seals (e.g., gaskets or O-rings752) in order to seal the vacuum internal to the enclosure104. For example, two grooves are illustrated as O-ring holders722inFIG.7C. In some implementations, the retaining cap604may include other components or structures, such as a vacuum hose adapter to which a vacuum hose may be attached to pull the vacuum in the enclosure104.

In some implementations, the retaining cap604may include adjustable bolt holes724or slots through which the retaining cap604may be bolted to the enclosure104, such as the base ring240as noted above. For example, the retaining cap604may be bolted at various positions, which increases adjustability of the retaining cap604, hex lock606, and nut bearing holder264combination, so that more precise rotations and, therefore, heights may be locked.

FIG.7Dillustrates a bottom view of an example nut bearing holder264with a nut hex lock606removed therefrom. As illustrated in the example, a nut bearing holder264may be rotated to move it upwards or downwards in the base ring240and/or lower sleeve608. The nut bearing holder264may hold a bearing266, which, in turn, holds the lower/bottom axle408bof the flywheel402. In some implementations, the nut bearing holder264may be open at a center/bottom so that the bottom axle408bis visible, although other implementations are possible and contemplated herein. Once the nut bearing holder264is rotated to a correct rotation/height, the hex lock606and/or retaining cap604may be placed thereon to secure its rotation and therefore the vertical/Z height of the flywheel402.

FIG.7Eillustrates a top view of an example nut bearing holder264. The example nut bearing holder264may have the illustrated configuration, although other configurations are possible. Additionally, the nut bearing holder264is illustrated without threads for clarity but, in some implementations, it may include threads on an outer face738to allow it to be twisted up or down. The bearing(s)266are also removed from the bearing holder732in order to illustrate an example structure of the nut bearing holder264.

The nut bearing holder264may have a hex interface740and/or notches to allow it to interact with tools and/or the hex lock606. The hex interface740may be located at the bottom of the nut bearing holder264, for example, below the outer face738and bearing holder264.

The nut bearing holder264may have a bearing holder body734with an outer face738and a bearing holder portion732on the inside that holds one or more bearings266. For instance, the bearing holder body734may be cylindrical with threads on a radially outward face and a hollowed-out core configured to hold one or more bearings266. The core or center of the bearing holder portion732may support vertical and/or horizontal bearings266, such as on one or more bearing steps736. In some implementations, the bearing holder body734may include a cavity at a center, such as is illustrated, to hold the flywheel axle408bor let it pass therethrough.

The nut bearing holder264may be resized, elongated, or widened based on the size of axle408band/or tightening tool being used. Furthermore, other configurations are possible and contemplated, such as where the nut bearing holder264additionally or alternatively holds a shipping ring262, where the nut bearing holder264has a different shape, or otherwise.

FIG.7Fillustrates an example lower bearing266in a flywheel enclosure104with the nut bearing holder264and bottom axle408bremoved to show the other example components. Although the bearing holder264has been removed, the bearing(s)266is illustrated to show their positioning. The bearing(s)266may move upward or downward in the aperture based on rotation of the nut bearing holder264.

As shown, the bearings266may be held at the center of an aperture/hole in the enclosure104bottom. The enclosure104bottom may include a base ring240coupled with a bottom plate236and bottom rib238to provide strength to support the flywheel402. In some implementations, the base ring240may include a lower sleeve608that is positioned between a portion of the nut bearing holder264and the base ring240to provide threads and/or reduce vibrations (e.g., from a space around the nut bearing holder264). In some implementations, the base ring240or other components may be coupled with a bolt plate754at the bottom of the enclosure104tub, which may securely hold the lower bearing266assembly in place.

In some implementations, the nut bearing holder264, lower sleeve608, space around the nut bearing holder264, or other area of the lower bearing266assembly may include one or more sensors756that relay bearing266or flywheel402health/status to the flywheel CPU/CNS/controller. For instance, a temperature sensor756aand an acceleration sensor756bmay be placed at the bearing266to detect bearing266wear and/or failure or other anomalous conditions. Wiring for the sensors756may pass through a retaining cap604or through the side of the enclosure104, as illustrated elsewhere herein.

FIG.7Gillustrates a top view of an example cap hex lock606, and nut bearing holder264in an assembled position, but with the flywheel402, flywheel enclosure104, and nut bearing holder264omitted for clarity.

The example raised area(s)726of the retaining cap604are illustrated supporting the cap hex lock606to keep it in place. Hex lock interaction element(s)728of the retaining cap604are also shown interacting with locking protrusions712of the hex lock606. For instance, the interaction elements728are held in between pairs of the locking protrusions712around an outer edge of the cap hex lock606. It should be noted that different configurations, such as pairs of protrusions being on the cap604instead of or in addition to the hex lock606are possible. Similarly, other structures in which the components are rotationally locked are possible and contemplated herein.

It should be noted that although the cap hex lock606and retaining cap604are illustrated as separate components, in some implementations, they may be integrated into a single component. For instance, an inner diameter of the retaining cap604may include teeth714configured as the hex lock606. Accordingly, while separating these components may provide easier manufacturability and assembly, they may be combined into a single unit designed to hold the nut bearing holder264in place, for example, at various rotations and corresponding heights.

FIG.7Hillustrates a top view of an example retaining cap604, cap hex lock606, and nut bearing holder264in an assembled position, but with the flywheel402and flywheel enclosure104omitted for clarity. In the depicted example, the assembled retaining cap604and cap hex lock606are shown in a locking position to prevent the nut bearing holder264from rotating.

In addition to the interactions described above between the retaining cap604and the cap hex lock606, the teeth714of the hex lock606are shown interacting with the corners of the hexagonal/hex interface740of the nut bearing holder264to rotationally lock the hex lock606with the nut bearing holder264.

The retaining cap604may be bolted with the base ring240or other component of the flywheel enclosure104. For example, a technician may position the nut bearing holder264(e.g., as a correct height, as noted above), place the cap hex lock606in the retaining cap604, and then place the retaining cap604onto the base ring240while rotating it slightly (e.g., using adjustability provided by the bolt holes/slots) until the teeth714of the hex lock606fall into place with the nut bearing holder264. The bolts of the retaining cap604may then be tightened to the base ring240of the enclosure104to secure the entire assembly in the set position and, in some instances, seal an internal vacuum.

FIG.8is a block diagram illustrating a method of building a flywheel assembly102, such as placing a flywheel402into a flywheel enclosure104and moving the flywheel402from a storage or shipping position to an active position. It should be noted that the operations provided are illustrative examples and that variations are possible and contemplated herein, such as where the order of operations is changed, various operations are omitted or added, or otherwise.

In some implementations, at804, a bottom bearing assembly and/or flywheel402may be set at a storage or shipping position, for example, using a vertical adjustment bolt or nut264. For example, an axle408support may be completely twisted downward, so that it (e.g., via a bearing) does not vertically support the flywheel402. As described above, where the flywheel402is in a shipping position, it may rest on a shipping ring262or similar structure to avoid damaging the bearings during shipping. In some implementations, other clamps, packing materials, bolts, or devices may be used to further secure the flywheel402from shifting during shipping.

In other implementations, the top and/or bottom bearings may be completely removed or otherwise disengaged to prevent damage to the bearings during transport of the MESU102or flywheel assembly102. In such instances, as noted below at814, the flywheel402may be adjusted and/or the bearings reengaged or re-inserted.

In some implementations, at806, the flywheel402may be placed in the enclosure tub126with a bottom axle408binserted into the bottom bearing assembly. For instance, the bottom bearing assembly may hold the axle408horizontally. Where a bottom axle408bholder has been moved to a shipping position, a bottom area of the bottom clamping plate120bmay rest on a shipping ring262or disposable shipping support. In some implementations, the bottom of the clamping plate120band the shipping ring262(e.g., with ridges, protrusions, channels, etc.) may prevent the flywheel402from shifting on the shipping ring262or shipping support during transport.

In some implementations, at808, the enclosure104lid may be attached and sealed to the enclosure tub126. The enclosure104lid may include O-rings or other seals (e.g., caulk, welds, etc.) may be used to seal it. The enclosure104lid may be bolted to a top ring of the enclosure tub126. The top axle408aof the flywheel402may be inserted into a top bearing assembly when the enclosure104lid is lowered onto the enclosure tub126.

In some implementations, various components may be pre-assembled onto the enclosure104lid, such as the motor-bearing, controller, or components described or illustrated herein. In some implementations, after the enclosure104lid is assembled onto the enclosure104, the other components of the flywheel assembly102may be assembled.

In some implementations, at810, the MESU102/flywheel assembly102may be transported to an installation location and installed. For instance, the legs thereof may be bolted to a concrete base or other structure. In some implementations, the flywheel assembly102may be placed into an enclosure104or case that is decorative or protects it from the elements. The flywheel assembly102may be placed fully or partially underground, above ground in a water-resistant enclosure104or otherwise. In some instances, where additional cooling is needed, the enclosure104may include vents, fans, or a radiator.

The flywheel assembly102may be installed at a residence in a utility room or adjacent to a service panel, or the flywheel assembly102may be installed with other flywheels402.

In some implementations, at812, a position of the flywheel402may be adjusted into an active position using a vertical adjustment bolt, clamp, axle408holder, external lift, or other device. For instance, an axle408holder may be twisted upward to engage a lower bearing (e.g.,266) with the flywheel402and lift it from a shipping ring262.

In some implementations, the flywheel402may be raised, using an axle holder, lift, or other device (whether from the top or bottom), until the flywheel402contacts a top structure, such as the magnetic lift member (e.g., magnets located at the top of the enclosure104to pull the flywheel402against a top bearing or limit the force on a bottom bearing), an enclosure104lid, or another structure, or the flywheel402may be raised until another condition is satisfied, such as a measured rotation of the nut bearing holder264, a measured height or offset from a structure, etc. For example, the flywheel402may be raised until a top clamping plate120acontacts the magnetic lift member152or a top bearing. The flywheel402may be lowered slightly to avoid contact with a structure or magnetic lift member152.

Once the vertical position of the flywheel402has been set, a retaining cap and/or hex lock606may be placed on the nut bearing holder264to lock the flywheel's402vertical position. Similarly, the retaining cap may be sealed using integrated O-rings or other seals.

Other openings in the enclosure104may also be closed or sealed, a vacuum valve may be opened, and other preparations may be performed.

In some implementations, at814, where the top and/or bottom bearings were removed or otherwise disengaged during shipping, a technician may reinsert or reengage the bearings. For instance, a shipping holder may be removed and/or a bottom bearing may be inserted into a channel or cylinder at the bottom of the flywheel enclosure104to bridge the gap between the cylinder and the bottom axle408b. In some implementations, similar actions may be performed to install one or more top axle bearings.

In some implementations, at816, the MESU102/flywheel assembly102may be connected to an external electrical network. For example, the motor-generator110, control unit, or other components may be coupled with an external energy source, load, or power grid. An inverter may be coupled with an external circuit breaker, and a controller may be connected to a communications network. Accordingly, for example, energy received from a grid or renewable energy source (e.g., solar panels) may be received, converted into A/C (e.g., based on a motor-generator type), and used to spin up the flywheel402. Similarly, when electrical power is requested, the motor-generator110may receive energy from the flywheel402to provide the power.

In some implementations, at818, a vacuum may be engaged for the enclosure104to reduce internal air pressure in the enclosure104, which may reduce energy losses due to air resistance. The vacuum may be permanent or maintained by an attached vacuum assembly108. The vacuum assembly108may be set to run at defined intervals or pressures (e.g., based on a pressure sensor). The vacuum assembly108may receive its power from the flywheel402, supercapacitor106, chemical battery, and/or external grid.

In some implementations, at820, the flywheel402may be spun up or down based on received power, requested power, or a data signal. For instance, when excess power is fed into the motor-generator110, the motor-generator110spins the flywheel402more quickly. Similarly, when power is requested, the motor-generator110may generate current from on the rotation of the flywheel402. The flow of energy may be controlled by a controller, which may be controlled based on received signals (e.g., from a server or connected computer).

The flywheel402controller may measure various parameters of the flywheel402, such as its rotational frequency, using sensors in the bearings or otherwise coupled with the flywheel assembly102. The controller may instruct an inverter to receive or input power that keeps the flywheel402within certain RPMs. For instance, the controller may measure the RPM and keep the flywheel402from spinning too quickly beyond safe limits, which may be set based on flywheel402size, material strengths, desired energy storage capacity, regulations, etc. For example, the limits may keep the flywheel402at less than 15,000 or 25,000 RPMs, although other implementations are possible.

In the foregoing description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the technology. It will be apparent, however, that the technology described herein can be practiced without these specific details.

Reference in the specification to “one implementation”, “an implementation”, “some implementations”, or “other implementations” means that a particular feature, structure, or characteristic described in connection with the implementation is included in at least one implementation of the disclosure. The appearances of the term “implementation” or “implementations” in various places in the specification are not necessarily all referring to the same implementation.

In addition, it should be understood and appreciated that variations, combinations, and equivalents of the specific implementations, implementations, and examples may exist, are contemplated, and are encompassed hereby. The invention should therefore not be limited by the above-described implementations, implementations, and examples, but by all implementations, implementations, and examples, and other equivalents within the scope and spirit of the invention as claimed.