Energy storage flywheel and energy storage device

Abstract

The application discloses a kind of energy storage flywheel and energy storage equipment, the energy storage flywheel includes shell, flywheel rotor, radial magnetic bearing, axial magnetic bearing and central bearing assembly, central bearing assembly includes inner shaft and outer sleeve, inner shaft is located in shell, outer sleeve is rotatably sleeved on inner shaft, and inner shaft is collinear with the central axis of flywheel rotor, inner shaft is movable along the extension direction of its central axis between locking position and release position, in locking position, outer sleeve is connected with flywheel rotor, in release position, outer sleeve is separated from flywheel rotor.The energy storage flywheel of the application can not only use magnetic bearing to support flywheel to reduce energy loss under normal operating conditions, but also use the hard support of central bearing assembly to improve the impact resistance of energy storage flywheel when flywheel rotor rotates at high speed or is impacted by larger load, to ensure that energy storage flywheel can maintain stable operation under different working conditions.

Description

Technical Field

[0001] This invention relates to the field of energy storage equipment technology, and in particular to an energy storage flywheel and an energy storage device. Background Technology

[0002] Flywheel energy storage systems are highly efficient and energy-saving inertial energy storage devices. They utilize a high-speed rotating flywheel to store energy and convert mechanical energy into electrical energy through an electromechanical energy conversion device. To reduce energy loss, energy storage flywheels in related technologies typically use magnetic bearings as the balance support structure for the flywheel rotor. However, when dealing with high-speed rotation or large impact loads on the flywheel rotor, magnetic bearings struggle to meet the rotor's stiffness requirements, leading to instability in the energy storage flywheel structure. Using mechanical bearings, on the other hand, results in significant energy loss and component wear. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose an energy storage flywheel, which is equipped with both a central bearing assembly and a magnetic bearing. The flywheel can autonomously switch the support state of the central bearing assembly on the flywheel rotor according to different operating conditions. Under normal operating conditions, the magnetic bearing supports the flywheel rotor to reduce energy loss by utilizing the resistance-free rotation of the magnetic bearing. Conversely, when the flywheel rotor rotates at high speed or is subjected to large load impacts, the rigid support of the central bearing assembly enhances the impact resistance of the energy storage flywheel, ensuring stable operation under different conditions.

[0004] An embodiment of the present invention also proposes an energy storage device.

[0005] The energy storage flywheel of this invention includes: a housing; a flywheel rotor, a radial magnetic bearing, and an axial magnetic bearing, wherein the flywheel rotor is disposed within the housing, the rotor of the radial magnetic bearing is sleeved on the flywheel rotor, the stator of the radial magnetic bearing is connected to the housing and spaced around the outer periphery of the rotor of the radial magnetic bearing, and the axial magnetic bearing is disposed on the inner top surface and inner bottom surface of the housing; and a central bearing assembly, the central bearing assembly including an inner shaft and an outer sleeve, the inner shaft being disposed within the housing and connected to the top plate and / or bottom plate of the housing, and the inner shaft extending axially along the flywheel rotor, the outer sleeve being rotatably sleeved on the inner shaft, the central axis of the inner shaft being collinear with the central axis of the flywheel rotor, the inner shaft being movable between a locked position and a released position along the extension direction of its central axis, in the locked position the outer sleeve being connected to the flywheel rotor, and in the released position the outer sleeve being separated from the flywheel rotor.

[0006] According to an embodiment of the present invention, an energy storage flywheel has a radial magnetic bearing sleeved on the flywheel rotor, and an axial magnetic bearing disposed on the inner top and inner bottom surfaces of the housing. A central bearing assembly includes an inner shaft and an outer sleeve. The inner shaft is disposed within the housing and connected to the top plate and / or bottom plate of the housing. The outer sleeve is rotatably sleeved on the inner shaft, and the inner shaft is collinear with the central axis of the flywheel rotor. The inner shaft is movable between a locked position and a released position along the extension direction of its central axis. In the locked position, the outer sleeve is connected to the flywheel rotor; in the released position, the outer sleeve is separated from the flywheel rotor. Therefore, when the flywheel rotor requires high-rigidity support, the axial locking position of the inner shaft can be controlled to connect the outer sleeve to the flywheel rotor. At this time, the central bearing assembly can act as a mechanical bearing to provide rigid support to the flywheel rotor, ensuring the structural stability of the energy storage flywheel. Qualitatively, when the flywheel rotor does not require high-rigidity support, the inner axial release position can be controlled to separate the outer sleeve from the flywheel rotor. At this time, the central bearing assembly no longer provides support force to the flywheel rotor, and the flywheel rotor instead uses the magnetic force of the magnetic bearing to maintain balance, thereby reducing energy loss and component wear caused by mechanical friction. Thus, the energy storage flywheel of this application can autonomously switch the support state of the central bearing assembly on the flywheel rotor according to different operating conditions. It can reduce the energy loss of the energy storage flywheel by utilizing the resistance-free rotation of the magnetic bearing under normal operating conditions, and improve the impact resistance of the energy storage flywheel by utilizing the rigid support of the central bearing assembly when the flywheel rotor rotates at high speed or is subjected to large load impacts, ensuring that the energy storage flywheel can maintain stable operation under different operating conditions.

[0007] In some embodiments, the flywheel rotor has a mating groove on its end face facing the inner shaft. In the locked position, the outer peripheral surface of the outer sleeve is in contact with the inner peripheral surface of the mating groove. In the released position, the outer peripheral surface of the outer sleeve is separated from the inner peripheral surface of the mating groove.

[0008] In some embodiments, the outer peripheral surface of the outer jacket is a conical surface, the cross-sectional area of ​​the conical surface gradually decreases along the direction toward the mating groove, and the inner peripheral surface of the mating groove is adapted to the conical surface.

[0009] In some embodiments, a control component is also included, which is disposed within the housing and is capable of driving the inner shaft to move between the locked position and the released position.

[0010] In some embodiments, the control component includes an electromagnet and an induction magnet. The electromagnet is connected to the housing and located on the side of the central bearing assembly opposite to the flywheel rotor. The induction magnet is located at the end of the inner shaft facing the electromagnet. The electromagnet can be supplied with current in different directions.

[0011] In some embodiments, the housing includes a body and an outer casing, the flywheel rotor is disposed within the body and the top plate and / or bottom plate of the body are provided with through holes opposite to the flywheel rotor, the outer casing is connected to the outside of the body and covers the opening of the through hole, the inner shaft is disposed within the body and partially fits within the through hole, and the electromagnet is disposed within the outer casing.

[0012] In some embodiments, a limiting block is provided on one of the outer peripheral surface of the inner shaft and the inner peripheral surface of the through hole, and a limiting groove is provided on the other. Both the limiting block and the limiting groove extend along the axial direction of the flywheel rotor, and the limiting block is slidably fitted in the limiting groove.

[0013] In some embodiments, a protruding ring is provided on the outer side of the top plate and / or bottom plate of the body, the through hole passes through the protruding ring, and the outer cover is sleeved on the protruding ring.

[0014] In some embodiments, the inner shaft includes a first shaft segment and a second shaft segment, the first shaft segment being located within the body, at least a portion of the second shaft segment being located within the through hole, and the cross-sectional area of ​​the first shaft segment being larger than the cross-sectional area of ​​the second shaft segment.

[0015] The energy storage device in this embodiment of the invention includes the energy storage flywheel described in the above embodiments.

[0016] The energy storage device according to the embodiments of the present invention, by adopting the energy storage flywheel described in the above embodiments, can actively switch its shock resistance performance in different working scenarios and has a long service life. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the energy storage flywheel according to an embodiment of the present invention.

[0018] Figure 2 This is a partially enlarged view of the energy storage flywheel according to an embodiment of the present invention.

[0019] Figure label:

[0020] Housing 1, body 11, outer cover 12, convex ring 13, limiting groove 131, flywheel rotor 2, radial magnetic bearing 3, axial magnetic bearing 4, central bearing assembly 5, inner shaft 51, limiting block 511, first shaft section 512, second shaft section 513, outer sleeve 52, control assembly 6, electromagnet 61, induction magnet 62. Detailed Implementation

[0021] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0022] The energy storage flywheel of this embodiment of the invention includes a housing 1, a flywheel rotor 2, a radial magnetic bearing 3, an axial magnetic bearing 4, and a central bearing assembly 5.

[0023] Specifically, the flywheel rotor 2 is disposed inside the housing 1, the rotor of the radial magnetic bearing 3 is sleeved on the flywheel rotor 2, the stator of the radial magnetic bearing 3 is connected to the housing 1 and spaced around the outer periphery of the rotor of the radial magnetic bearing 3, the axial magnetic bearing 4 is disposed on the inner top surface and inner bottom surface of the housing 1, and the central bearing assembly 5 includes an inner shaft 51 and an outer sleeve 52. The inner shaft 51 is disposed inside the housing 1 and connected to the top plate and / or bottom plate of the housing 1, and the inner shaft 51 extends along the axial direction of the flywheel rotor 2. The outer sleeve 52 is rotatably sleeved on the inner shaft 51. The central axis of the inner shaft 51 is collinear with the central axis of the flywheel rotor 2. The inner shaft 51 is movable between a locked position and a released position along the extension direction of its central axis. In the locked position, the outer sleeve 52 is connected to the flywheel rotor 2, and in the released position, the outer sleeve 52 is separated from the flywheel rotor 2. It is understood that rolling elements are provided between the inner shaft 51 and the outer sleeve 52 of the central bearing assembly 5 to allow the outer sleeve 52 to rotate relative to the inner circumference 51, as can be seen from the structure of commonly used mechanical bearings. Preferably, the top plate and bottom plate of the housing 1 are provided with central bearing assemblies 5, which are used to support the upper and lower ends of the flywheel rotor 2, respectively.

[0024] It should be noted that, depending on the different operating scenarios of the energy storage flywheel, the flywheel rotor 2 needs to meet different support stiffness requirements to ensure that the flywheel rotor 2 does not become unbalanced. Specifically, when the flywheel rotor 2 maintains a low to medium speed rotation, the balance of the flywheel rotor 2 can be maintained by using the axial magnetic bearing 4 and the radial magnetic bearing 3. That is, the magnetic force generated by the magnetic bearing can meet the flywheel rotor's support stiffness requirements.

[0025] When the flywheel rotor 2 needs to maintain high-speed rotation, the magnetic support provided by the magnetic bearing alone is insufficient to maintain the balance of the flywheel rotor 2. At this time, the central bearing assembly 5 of this application can be used to support the flywheel rotor 2 instead of the mechanical bearing, making up for the lack of support stiffness of the magnetic bearing, avoiding the flywheel rotor 5 from becoming unbalanced under high-speed rotation, and ensuring that the energy storage flywheel can remain stable under any operating environment.

[0026] Specifically, when the flywheel rotor 2 requires high rigidity support, the inner shaft 51 can be controlled to move to the locking position so that the outer sleeve 52 is connected to the flywheel rotor 2. At this time, the central bearing assembly 5 can act as a mechanical bearing to provide rigid support to the flywheel rotor 2, ensuring the structural stability of the energy storage flywheel. When the flywheel rotor 2 does not require high rigidity support, the inner shaft 51 can be controlled to move to the release position so that the outer sleeve 52 is separated from the flywheel rotor 2. At this time, the central bearing assembly 5 no longer provides support force to the flywheel rotor 2. Instead, the flywheel rotor 2 uses the magnetic force of the magnetic bearing to maintain balance, thereby reducing energy loss and component wear caused by mechanical friction.

[0027] In other words, by simultaneously setting the central bearing assembly 5 and the magnetic bearing, this application allows for selective switching of the state of the central bearing assembly 5 according to the support stiffness requirements of the flywheel rotor under different operating conditions. When the flywheel rotor 2 requires high support stiffness, the central bearing assembly 5 provides rigid support for the flywheel rotor 2 to ensure its smooth rotation. When high support stiffness is not required, only the magnetic bearing is used to support the flywheel rotor 2, thereby reducing energy consumption.

[0028] In addition, the central bearing assembly 5 of this application can also serve as an emergency support shaft. When a sudden situation causes an impact on the flywheel rotor 2, the central bearing assembly 5 can cooperate with the flywheel rotor 2 autonomously to maintain the balance of the flywheel rotor 2 through rigid support.

[0029] According to an embodiment of the present invention, an energy storage flywheel has a radial magnetic bearing sleeved on the flywheel rotor, and an axial magnetic bearing disposed on the inner top and inner bottom surfaces of the housing. A central bearing assembly includes an inner shaft and an outer sleeve. The inner shaft is disposed within the housing and connected to the top plate and / or bottom plate of the housing. The outer sleeve is rotatably sleeved on the inner shaft, and the inner shaft is collinear with the central axis of the flywheel rotor. The inner shaft is movable between a locked position and a released position along the extension direction of its central axis. In the locked position, the outer sleeve is connected to the flywheel rotor; in the released position, the outer sleeve is separated from the flywheel rotor. Therefore, when the flywheel rotor requires high-rigidity support, the axial locking position of the inner shaft can be controlled to connect the outer sleeve to the flywheel rotor. At this time, the central bearing assembly can act as a mechanical bearing to provide rigid support to the flywheel rotor, ensuring the structural stability of the energy storage flywheel. Qualitatively, when the flywheel rotor does not require high-rigidity support, the inner axial release position can be controlled to separate the outer sleeve from the flywheel rotor. At this time, the central bearing assembly no longer provides support force to the flywheel rotor, and the flywheel rotor instead uses the magnetic force of the magnetic bearing to maintain balance, thereby reducing energy loss and component wear caused by mechanical friction. Thus, the energy storage flywheel of this application can autonomously switch the support state of the central bearing assembly on the flywheel rotor according to different operating conditions. It can reduce the energy loss of the energy storage flywheel by utilizing the resistance-free rotation of the magnetic bearing under normal operating conditions, and improve the impact resistance of the energy storage flywheel by utilizing the rigid support of the central bearing assembly when the flywheel rotor rotates at high speed or is subjected to large load impacts, ensuring that the energy storage flywheel can maintain stable operation under different operating conditions.

[0030] Furthermore, such as Figure 1 and Figure 2 As shown, the flywheel rotor 2 has a mating groove on the end face facing the inner shaft 51. In the locked position, the outer circumferential surface of the outer sleeve 52 fits against the inner circumferential surface of the mating groove. In the released position, the outer circumferential surface of the outer sleeve 52 separates from the inner circumferential surface of the mating groove.

[0031] Understandably, in the locked position, the rotation of the flywheel rotor 2 can drive the outer sleeve 52 to rotate around the inner shaft 51. That is, at this time, the central bearing assembly 5 acts as a mechanical bearing to support the flywheel rotor 2. In the released position, since the outer sleeve 52 separates from the inner circumferential surface of the mating groove, the central bearing assembly 5 no longer supports the flywheel rotor 2. At this time, the balanced rotation of the flywheel rotor 2 is maintained only by the magnetic bearing.

[0032] It should be noted that the fit between the outer sleeve 52 and the flywheel rotor 2 is not limited to the fit between the outer sleeve 52 and the mating groove. As long as the central bearing assembly 5 and the flywheel rotor 2 can be detachably connected and the flywheel rotor 2 can be supported to rotate in a balanced manner after the connection is made, it is acceptable.

[0033] Furthermore, such as Figure 1 and Figure 2 As shown, the outer circumferential surface of the outer sleeve 52 is a conical surface, and the cross-sectional area of ​​the conical surface gradually decreases along the direction towards the mating groove. The inner circumferential surface of the mating groove is adapted to the conical surface, that is, the outer circumferential surface of the outer sleeve 52 and the inner circumferential surface of the mating groove are wedge-shaped. When the outer sleeve 52 needs to be connected to the mating groove, the outer sleeve 52 is completely wedged into the mating groove. When the outer sleeve 52 needs to be separated from the mating groove, the inner shaft 51 only needs to drive the outer sleeve 52 to move up / down in a short stroke. The control method is simple and quick, and the wear of the mating parts is relatively small.

[0034] Furthermore, such as Figure 1 and Figure 2 As shown, the energy storage flywheel also includes a control component 6, which is located inside the housing 1. The control component 6 can drive the inner shaft 51 to move between a locked position and a released position. That is, the control component 6 can actively control the switching of the support state of the central bearing assembly 5 on the flywheel rotor 2. When high rigidity support is required, the control central bearing assembly 5 supports the flywheel rotor 2 to maintain the balance of the flywheel rotor 2 when rotating at high speed or subjected to large impact loads. When rotating at medium and low speeds, the control central bearing assembly 5 separates from the flywheel rotor 2, and only the magnetic bearing is used to maintain the balance of the flywheel rotor, thereby reducing energy loss.

[0035] Optionally, such as Figure 1 and Figure 2 As shown, the control component 6 includes an electromagnet 61 and an induction magnet 62. The electromagnet 61 is connected to the housing 1 and is located on the side of the central bearing assembly 5 away from the flywheel rotor 2. The induction magnet 62 is located at the end of the inner shaft 51 facing the electromagnet 61. The electromagnet 61 can be supplied with current in different directions.

[0036] In other words, the induction magnet 62 is fixed on the end face of the inner shaft 51, the electromagnet 61 is fixed inside the housing 1, and the electromagnet 61 and the induction magnet 62 are arranged opposite to each other. The direction of the magnetic pole of the electromagnet 61 can be changed by inputting current in different directions. Thus, under the action of the magnetic field, the electromagnet 61 and the induction magnet 62 can attract or repel each other, thereby driving the central bearing assembly 5 to move between the locked position and the released position.

[0037] Specifically, when it is necessary to control the central bearing assembly 5 to move towards the locking position, a positive current can be passed through the electromagnet 6. At this time, a repulsive force is generated between the electromagnet 6 and the induction magnet 62. This repulsive force can push the central bearing assembly 5 towards the mating groove until the outer sleeve 52 is in contact with the inner circumferential surface of the mating groove. When it is necessary to control the central bearing assembly 5 to move towards the release position, a reverse current can be passed through the electromagnet 6. At this time, a mutual attractive force is generated between the electromagnet 6 and the induction magnet 62. This attractive force can push the central bearing assembly 5 back to separate the outer sleeve 52 from the inner circumferential surface of the mating groove.

[0038] Furthermore, such as Figure 1 and Figure 2 As shown, the housing 1 includes a body 11 and an outer casing 12. The flywheel rotor 2 is located inside the body 11, and the top plate and / or bottom plate of the body 11 are provided with through holes opposite to the flywheel rotor 2. The outer casing 12 is connected to the outside of the body 11 and covers the opening of the through hole. The inner shaft 51 is located inside the body 11 and partially fits into the through hole. The electromagnet 61 is located inside the outer casing 12.

[0039] Understandably, the opening of the through hole should be opposite to the central shaft of the flywheel rotor 2. The outer casing 12 can cover the opening of the through hole, thereby preventing debris from falling into the body 11. At the same time, an electromagnet 61 is installed inside the outer casing 12, which can protect the coil and yoke structure of the electromagnet 61 and prevent the electromagnet 61 from being accidentally bumped. Furthermore, the electromagnet 61 located inside the outer casing 12 and the flywheel rotor 2 located inside the body 11 are not in the same assembly space, and the electromagnet 61 will not occupy the assembly space of the flywheel rotor 2.

[0040] Furthermore, such as Figure 1 and Figure 2 As shown, a limiting block 511 is provided on one of the outer peripheral surface of the inner shaft 51 and the inner peripheral surface of the through hole, and a limiting groove 131 is provided on the other. Both the limiting block 511 and the limiting groove 131 extend along the axial direction of the flywheel rotor 2, and the limiting block 511 is slidably fitted in the limiting groove 131.

[0041] In other words, the inner shaft 51 is engaged with the body 11 on the inner circumferential surface of the through hole through the limiting groove 131 and the limiting block 511. This prevents the inner shaft 51 from rotating and causing a "false rotation". At the same time, the limiting groove 131 and the limiting block 511 can slide relative to each other along the axial direction of the flywheel rotor 2, thereby guiding the movement of the inner shaft 51 and ensuring that the inner shaft 51 moves between the locked position and the released position along the axial direction of the flywheel rotor 2.

[0042] Furthermore, such as Figure 1 and Figure 2 As shown, a protruding ring 13 is provided on the outer side of the top plate and / or bottom plate of the body 11, and a through hole passes through the protruding ring 13. The outer cover 12 is sleeved on the protruding ring 13. Preferably, both the top plate and the bottom plate of the body 11 are provided with through holes and corresponding protruding rings 13.

[0043] Understandably, the convex ring 13 facilitates the assembly of the outer cover 12 and achieves sealing through the cooperation between the outer cover 12 and the convex ring 13. On the other hand, the convex ring 13 can increase the axial length of the through hole to meet the travel requirements of the central bearing assembly 5.

[0044] Optionally, the outer casing 12 has a cylindrical portion that is fitted onto the convex ring 13. The end of the cylindrical portion facing the body 11 has a circumferentially extending flange that fits against the top plate and / or bottom plate of the body 11. Thus, a sealed connection can be formed between the inner circumferential surface of the cylindrical portion and the outer circumferential surface of the convex ring 13, as well as between the flange and the body 11. This double seal ensures the airtightness of the connection between the outer casing 12 and the body 11.

[0045] Furthermore, such as Figure 1 and Figure 2 As shown, the inner shaft 51 includes a first shaft segment 512 and a second shaft segment 513. The first shaft segment 512 is located inside the body 11, and at least a portion of the second shaft segment 513 is located inside the through hole. The cross-sectional area of ​​the first shaft segment 512 is larger than the cross-sectional area of ​​the second shaft segment 513.

[0046] In other words, the outer diameter of the first shaft segment 512 is larger than the inner diameter of the through hole, and the outer diameter of the second shaft segment 513 is the same as the inner diameter of the first shaft segment 512. Thus, a stepped mating surface is formed between the first shaft segment 512 and the second shaft segment 513 of the inner shaft 51. This stepped mating surface can stop against the outer peripheral area of ​​the through hole, thereby limiting the axial displacement of the inner shaft 51 and preventing the central bearing assembly 5 from overtravel.

[0047] Optionally, the energy storage flywheel also includes a disc motor assembly 7, the motor stator of which is disposed on the top plate and / or bottom plate of the body 11, and the motor rotor of which is embedded on the end face of the flywheel rotor 2 facing the motor stator.

[0048] The energy storage device in this embodiment of the invention includes the energy storage flywheel described in the above embodiment.

[0049] According to the energy storage device of the present invention, by adopting the energy storage flywheel of the above embodiment, it can actively switch its shock resistance performance in different working scenarios and has a long service life.

[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0055] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. An energy storage flywheel, characterized in that, include: case; The system comprises a flywheel rotor, a radial magnetic bearing, and an axial magnetic bearing. The flywheel rotor is disposed within the housing. The rotor of the radial magnetic bearing is sleeved on the flywheel rotor. The stator of the radial magnetic bearing is connected to the housing and spaced around the outer periphery of the rotor of the radial magnetic bearing. The axial magnetic bearing is disposed on the inner top and inner bottom surfaces of the housing. A central bearing assembly includes an inner shaft and an outer sleeve. The inner shaft is disposed within a housing and connected to the top plate and / or bottom plate of the housing, extending axially along the flywheel rotor. The outer sleeve is rotatably fitted onto the inner shaft. The central axis of the inner shaft is collinear with the central axis of the flywheel rotor. The inner shaft is movable between a locked position and a released position along the extension direction of its central axis. In the locked position, the outer sleeve is connected to the flywheel rotor; in the released position, the outer sleeve is separated from the flywheel rotor. A mating groove is provided on the end face of the flywheel rotor facing the inner shaft. In the locked position, the outer circumferential surface of the outer sleeve is in contact with the inner circumferential surface of the mating groove; in the released position, the outer circumferential surface of the outer sleeve is separated from the inner circumferential surface of the mating groove. The outer circumferential surface of the outer sleeve is a tapered surface, the cross-sectional area of ​​which gradually decreases along the direction towards the mating groove. The inner circumferential surface of the mating groove is adapted to the tapered surface. A control assembly, housed within the housing, includes an electromagnet and an induction magnet. The electromagnet is connected to the housing and located on the side of the central bearing assembly opposite to the flywheel rotor. The induction magnet is located at the end of the inner shaft facing the electromagnet. The electromagnet can be supplied with current in different directions. The control assembly can drive the inner shaft to move between a locked position and a released position. When the flywheel rotor requires high rigidity support, the inner shaft can be controlled to move to the locked position, connecting the outer casing to the flywheel rotor. In this case, the central bearing assembly can act as a mechanical bearing, providing rigid support to the flywheel rotor. When the flywheel rotor does not require high rigidity support, the inner shaft can be controlled to move to the released position, separating the outer casing from the flywheel rotor. In this case, the central bearing assembly no longer provides support force to the flywheel rotor, and the flywheel rotor instead utilizes the magnetic force of the magnetic bearing to maintain balance.

2. The energy storage flywheel according to claim 1, characterized in that, The housing includes a main body and an outer casing. The flywheel rotor is disposed within the main body, and the top plate and / or bottom plate of the main body are provided with through holes opposite to the flywheel rotor. The outer casing is connected to the outside of the main body and covers the opening of the through hole. The inner shaft is disposed within the main body and partially fits into the through hole. The electromagnet is disposed within the outer casing.

3. The energy storage flywheel according to claim 2, characterized in that, A limiting block is provided on one of the outer peripheral surface of the inner shaft and the inner peripheral surface of the through hole, and a limiting groove is provided on the other. Both the limiting block and the limiting groove extend along the axial direction of the flywheel rotor, and the limiting block is slidably fitted in the limiting groove.

4. The energy storage flywheel according to claim 2, characterized in that, The outer side of the top plate and / or bottom plate of the main body is provided with a protruding ring, the through hole passes through the protruding ring, and the outer cover is sleeved on the protruding ring.

5. The energy storage flywheel according to claim 2, characterized in that, The inner shaft includes a first shaft segment and a second shaft segment. The first shaft segment is located within the body, and at least a portion of the second shaft segment is located within the through hole. The cross-sectional area of ​​the first shaft segment is larger than the cross-sectional area of ​​the second shaft segment.

6. An energy storage device, characterized in that, Includes an energy storage flywheel according to any one of claims 1-5.

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