Flywheel energy storage device

Abstract

The application relates to a flywheel energy storage device. The flywheel energy storage device comprises a shell, a rotor assembly and a stator assembly, and the shell is provided with a containing cavity. The rotor assembly is arranged in the containing cavity, and the rotor assembly comprises a flywheel rotor and a rotating shaft, the flywheel rotor is connected to the rotating shaft, and the rotating shaft is rotatably connected to the shell. The stator assembly is connected to the shell, and the stator assembly is movably arranged coaxially at one end of the rotor assembly. When the flywheel energy storage device is in a charging or discharging state, the stator assembly is arranged at a charging and discharging position close to an end face of the flywheel rotor; when the flywheel energy storage device is in a standby running state, the stator assembly is arranged at a standby position away from the end face of the flywheel rotor. The flywheel energy storage device has the advantages of considering conversion efficiency and power.

Description

Technical Field

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

[0002] During operation, flywheel energy storage devices operate in three states: charging, discharging, and standby. Flywheel energy storage devices spend most of their time in standby mode, while the charging and discharging states are very short. Therefore, reducing standby losses is crucial to improving the energy conversion efficiency of flywheel energy storage devices.

[0003] Current flywheel energy storage devices consist of a rotor and a stator. If the stator has a core structure and the flywheel energy storage device is in a standby state for a long time, core losses will occur, increasing the standby loss of the flywheel energy storage device and reducing its energy conversion efficiency. If the stator adopts a coreless structure, stator core losses are eliminated, reducing the standby loss of the flywheel energy storage device. However, this increases the effective air gap length of the flywheel energy storage device, greatly reducing its power. This presents a drawback where the conversion efficiency and power of the flywheel energy storage device cannot be simultaneously achieved. Summary of the Invention

[0004] Therefore, it is necessary to provide a flywheel energy storage device to address the problem that conversion efficiency and power cannot be simultaneously achieved in flywheel energy storage devices.

[0005] This invention provides a flywheel energy storage device, comprising:

[0006] The housing has a receiving cavity;

[0007] A rotor assembly disposed in the receiving cavity, the rotor assembly including a flywheel rotor and a rotating shaft, the flywheel rotor being connected to the rotating shaft, the rotating shaft being rotatably connected to the housing;

[0008] A stator assembly is connected to the housing and is movably disposed at one end of the rotor assembly. When the flywheel energy storage device is in a charging or discharging state, the stator assembly is disposed at a charging / discharging position close to the end face of the flywheel rotor. When the flywheel energy storage device is in a standby operating state, the stator assembly is disposed at a standby position away from the end face of the flywheel rotor.

[0009] In one embodiment, the stator assembly includes a stator and an armature winding, the stator is connected to the housing, the stator has a plurality of stator teeth along the circumferential direction, and the armature winding is installed in a slot formed by two adjacent stator teeth.

[0010] In one embodiment, the housing includes a housing body, a first end cap, and a second end cap. The first end cap is disposed at one end of the housing body, and the second end cap is disposed at the other end of the housing body. The housing body, the first end cap, and the second end cap together form the receiving cavity. One end of the rotating shaft is mounted on the first end cap, and the other end of the rotating shaft is mounted on the second end cap. The stator assembly is movably disposed between the flywheel rotor and the first end cap.

[0011] In one embodiment, the first end cover is provided with a snap-fit ​​portion, and the stator is provided with a circumferential protrusion. When the stator is in the charging / discharging position, the protrusion abuts against the snap-fit ​​portion.

[0012] In one embodiment, the stator assembly further includes a first connector. The end face of the stator facing the first end cover is provided with a connecting groove, and the first end cover is provided with a first connecting hole. When the flywheel energy storage device is in a charging or discharging state, one end of the first connector passes through the first connecting hole, and the other end of the first connector abuts against the bottom of the connecting groove, so that the protrusion abuts against the snap-fit ​​portion.

[0013] In one embodiment, the first connector and the wall of the first connecting hole are connected by a first threaded pair.

[0014] In one embodiment, the stator assembly further includes a second connector, and the end face of the stator facing the first end cover is provided with a second connecting hole. The first end cover is provided with a third connecting hole. When the flywheel energy storage device is in standby operation, one end of the second connector is connected to the second connecting hole, and the other end of the second connector is connected to the third connecting hole, so that the stator assembly is set in the standby position.

[0015] In one embodiment, the second connector includes a bolt and a nut, the bolt being sequentially inserted through the second connecting hole and the third connecting hole, and the nut being connected to the end of the bolt that passes through the third connecting hole.

[0016] In one embodiment, the rotor assembly further includes a first bearing and a second bearing, the first end cover is provided with a first mounting seat, the first bearing is disposed on the first mounting seat, one end of the rotating shaft is mounted on the first bearing, the second end cover is provided with a second mounting seat, the second bearing is disposed on the second mounting seat, and the other end of the rotating shaft is mounted on the second bearing.

[0017] In one embodiment, the flywheel rotor has a protrusion on the end face facing the stator assembly, the protrusion forming a mounting groove around the circumference, the flywheel rotor also includes a permanent magnet and a filler, the permanent magnet being disposed around the mounting groove, and the filler filling the gaps in the mounting groove.

[0018] The aforementioned flywheel energy storage device has a rotor assembly and a stator assembly coaxially arranged within the housing cavity. The flywheel rotor of the rotor assembly rotates relative to the stator assembly via a shaft, enabling the flywheel energy storage device to perform charging or discharging functions. When the flywheel energy storage device is in a charging or discharging state, the stator assembly is positioned close to the flywheel rotor in the charging / discharging position, reducing the effective air gap of the flywheel energy storage device and thus increasing its power. When the flywheel energy storage device is in standby mode, the position of the stator assembly is adjusted to a standby position away from the flywheel rotor, increasing the effective air gap and significantly reducing the air gap magnetic flux density. At this time, the core loss of the stator assembly is almost negligible, effectively improving the energy conversion efficiency of the flywheel energy storage device. This embodiment, by adjusting the position of the stator assembly, increases the power of the flywheel energy storage device during charging or discharging and improves the energy conversion efficiency during standby mode, effectively balancing the conversion efficiency and power of the flywheel energy storage device. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the flywheel energy storage device described in an embodiment of this application.

[0020] Figure 2 This is a schematic diagram of the rotor assembly and stator assembly of the flywheel energy storage device described in the embodiments of this application.

[0021] Figure 3 This is a schematic diagram of the rotor assembly of the flywheel energy storage device described in an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the stator assembly of the flywheel energy storage device described in an embodiment of this application.

[0023] Figure 5 This is an assembly diagram of the rotor assembly and stator assembly of the flywheel energy storage device described in the embodiments of this application.

[0024] Figure 6 This is a schematic diagram of the flywheel energy storage device described in the embodiments of this application in a charging or discharging state.

[0025] Figure 7 This is a schematic diagram of the flywheel energy storage device described in the embodiment of this application in standby operation mode.

[0026] Icon labels:

[0027] 100, Housing; 100A, Receiving cavity; 110, Housing body; 120, First end cap; 121, Snap-fit ​​part; 120A, First connecting hole; 120B, Third connecting hole; 122, First mounting base; 130, Second end cap; 131, Second mounting base;

[0028] 200, Rotor assembly; 210, Flywheel rotor; 211, Protrusion; 212, Permanent magnet; 213, Filler; 220, Shaft; 230, First bearing; 240, Second bearing;

[0029] 300, Stator assembly; 310, Stator; 311, Stator tooth; 312, Lug; 310A, Connecting slot; 310B, Second connecting hole; 320, Armature winding; 330, First connector; 340, Second connector. Detailed Implementation

[0030] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0031] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0032] Furthermore, where the terms "first" and "second" appear, these terms are 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 with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0033] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," 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 or an electrical connection; 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 expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0034] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" 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. Similarly, "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.

[0035] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0036] See Figure 1 , Figure 2 , Figure 6 and Figure 7 The diagram shows a structural schematic of a flywheel energy storage device according to an embodiment of the present application. The flywheel energy storage device includes a housing 100, a rotor assembly 200 and a stator assembly 300. The housing 100 is provided with a receiving cavity 100A.

[0037] The rotor assembly 200 is disposed in the receiving cavity 100A. The rotor assembly 200 includes a flywheel rotor 210 and a rotating shaft 220. The flywheel rotor 210 is connected to the rotating shaft 220, and the rotating shaft 220 is rotatably connected to the housing 100. Specifically, the flywheel rotor 210 is made of a single piece of structural steel.

[0038] The stator assembly 300 is connected to the housing 100 and is movably disposed at one end of the rotor assembly 200. When the flywheel energy storage device is in a charging or discharging state, such as... Figure 6 As shown, the stator assembly 300 is positioned at the charging / discharging position near the end face of the flywheel rotor 210. When the flywheel energy storage device is in standby mode, as... Figure 7 As shown, the stator assembly 300 is positioned in a standby position away from the end face of the flywheel rotor 210. Specifically, the rotor assembly 200 and the stator assembly 300 are coaxially arranged.

[0039] The flywheel energy storage device described in this application embodiment has a rotor assembly 200 and a stator assembly 300 coaxially arranged within the accommodating cavity of the housing 100. The flywheel rotor 210 of the rotor assembly 200 rotates relative to the stator assembly 300 via a rotating shaft 220, enabling the flywheel energy storage device to perform charging or discharging functions. When the flywheel energy storage device is in a charging or discharging state, the stator assembly 300 is positioned close to the flywheel rotor 210 in a charging / discharging position, reducing the effective air gap of the flywheel energy storage device and thus increasing its power. When the flywheel energy storage device is in a standby operating state, the position of the stator assembly 300 is adjusted to a standby position away from the flywheel rotor 210, thereby increasing the effective air gap of the flywheel energy storage device and greatly reducing the air gap magnetic flux density. At this time, the core loss of the stator assembly 300 is almost negligible, effectively improving the energy conversion efficiency in the flywheel energy storage device.

[0040] The flywheel energy storage device described in this application embodiment increases power during charging or discharging and improves energy conversion efficiency during standby operation by adjusting the relative positions of the stator assembly 300 and the flywheel rotor 210 on the axis, effectively balancing the conversion efficiency and power of the flywheel energy storage device.

[0041] Combination Figure 4 and Figure 5 This diagram illustrates the structure of the stator assembly 300 of a flywheel energy storage device according to one embodiment of this application. In some embodiments, the stator assembly 300 includes a stator 310 and an armature winding 320. The stator 310 is connected to the housing 100 and has a plurality of stator teeth 311 arranged circumferentially. The armature winding 320 is installed in the slot formed by two adjacent stator teeth 311. The stator teeth 311 are the core structure of the stator 310. In the flywheel energy storage device, the armature winding 320 is wound in the slot formed by two adjacent stators 310 of the stator assembly 300. The circumferential stator teeth 311 of the stator 310 can effectively focus the magnetic field, reduce magnetic reluctance and harmonic interference, and, in conjunction with the armature winding 320, significantly improve the sinusoidal density of the air gap and the current response speed, thereby improving the efficiency of the flywheel energy storage device.

[0042] In an exemplary embodiment, the armature winding 320 is distributed in a concentrated winding manner in the stator 310, which is beneficial to the coil winding of the armature winding 320, thereby improving the slot fill factor of the armature winding 320.

[0043] In an optional embodiment, such as Figure 6 and Figure 7 As shown, the housing 100 includes a housing body 110, a first end cover 120, and a second end cover 130. The first end cover 120 is disposed on one end of the housing body 110, and the second end cover 130 is disposed on the other end of the housing body 110. The housing body 110, the first end cover 120, and the second end cover 130 together form a receiving cavity 100A. One end of the rotating shaft 220 is installed on the first end cover 120, and the other end of the rotating shaft 220 is installed on the second end cover 130. The stator assembly 300 is movably disposed between the flywheel rotor 210 and the first end cover 120.

[0044] In this embodiment, the shell body 110 has openings at both ends that communicate with the receiving cavity 100A. The shell body 100 is formed by covering the two ends of the shell body 110 with a first end cap 120 and a second end cap 130. Specifically, the shell 100 has a cylindrical structure, and the rotor assembly 200 and the stator assembly 300 are arranged in the receiving cavity 100A of the shell 100 along the axis of the shell 100.

[0045] In one exemplary embodiment, the shell body 110, the first end cap 120, and the second end cap 130 are made of stainless steel, which gives the shell 100 good corrosion resistance and durability.

[0046] In an optional embodiment, such as Figure 6 As shown, the first end cap 120 is provided with a snap-fit ​​portion 121, and the stator 310 is provided with a circumferential protrusion 312. When the stator 310 is in the charging / discharging position, the protrusion 312 abuts against the snap-fit ​​portion 121. Specifically, the snap-fit ​​portion 121 is an L-shaped cross-section ring, and the snap-fit ​​portion 121 is connected to the end of the first end cap 120 facing the receiving cavity 100A.

[0047] In this embodiment, when the stator 310 is installed in the snap-fit ​​part 121, the protruding edge 312 of the stator 310 abuts against the bottom edge of the snap-fit ​​part 121. At this time, the stator assembly 300 is in the charging and discharging position, and the effective air gap length of the flywheel energy storage device is small, thereby increasing the power of the flywheel energy storage device.

[0048] In an optional embodiment, such as Figure 4 and Figure 6 As shown, the stator assembly 300 also includes a first connector 330. The end face of the stator 310 facing the first end cover 120 is provided with a connecting groove 310A. The first end cover 120 is provided with a first connecting hole 120A. When the flywheel energy storage device is in a charging or discharging state, one end of the first connector 330 passes through the first connecting hole 120A, and the other end of the first connector 330 abuts against the bottom of the connecting groove 310A, so that the protrusion 312 abuts against the snap-fit ​​portion 121.

[0049] In order to keep the stator assembly 300 in the charging or discharging position during charging or discharging, the first connector 330 is inserted through the first connecting hole 120A, so that the first connector 330 abuts against the connecting groove 310A of the stator 310, thereby limiting the axial position of the stator assembly 300 and preventing the stator assembly 300 from being displaced. This ensures that the flywheel energy storage device maintains the power at its maximum value during charging or discharging, which has the advantage of high efficiency.

[0050] In an exemplary embodiment, the first connector 330 and the hole wall of the first connecting hole 120A are connected by a first threaded pair. Specifically, the first connector 330 is a bolt, and the first connecting hole 120A is a threaded hole. The bolt is inserted into the receiving cavity 100A through the threaded hole, so that the end of the bolt abuts against the connecting groove, thereby defining the axial position of the stator assembly 300.

[0051] In an optional embodiment, such as Figure 4 and Figure 7 As shown, the stator assembly 300 also includes a second connector 340. The end face of the stator 310 facing the first end cover 120 is also provided with a second connecting hole 310B. The first end cover 120 is provided with a third connecting hole 120B. When the flywheel energy storage device is in standby operation, one end of the second connector 340 is connected to the second connecting hole 310B, and the other end of the second connector 340 is connected to the third connecting hole 120B, so that the stator assembly 300 is set in the standby position.

[0052] When the flywheel energy storage device switches to standby operation, the first connector 330 is detached, and the second connector 340 is adjusted to switch the stator assembly 300 from the charging / discharging position to the standby position. At this time, the stator assembly 300 is far away from the rotor assembly 200, thereby increasing the effective air gap length of the flywheel energy storage device, reducing the loss of the flywheel energy storage device in standby mode, and thus improving the energy conversion efficiency of the flywheel energy storage device in standby operation mode.

[0053] An exemplary second connector 340 includes a bolt and a nut. The bolt passes sequentially through a second connecting hole 310B and a third connecting hole 120B, and the nut is connected to the end of the bolt that passes through the third connecting hole 120B. Specifically, the bolt exits from the receiving cavity 100A through the second connecting hole 310B and the third connecting hole 120B. After disassembling the first connector 330, the position of the nut on the bolt is adjusted by rotating the nut, thereby driving the stator assembly 300 from the charging / discharging position to the standby position, which has the advantage of being convenient to use.

[0054] In an exemplary embodiment, both the first connecting hole 120A and the connecting groove 310A include four holes. The four first connecting holes 120A are equally spaced along the circumference of the first end cover 120, and the four connecting grooves 310A are arranged along the circumference of the stator 310, corresponding to the four first connecting holes 120A. The third connecting hole 120B and the second connecting hole 310B include four holes. The four third connecting holes 120B are equally spaced along the circumference of the first end cover 120, and the four second connecting holes 310B are arranged along the circumference of the stator 310, corresponding to the four third connecting holes 120B.

[0055] In an optional embodiment, such as Figure 3 As shown, the flywheel rotor 210 has a protrusion 211 on the end face facing the stator assembly 300. The protrusion 211 forms a mounting groove around the circumference. The flywheel rotor 210 also includes a permanent magnet 212 and a filler 213. The permanent magnet 212 is arranged around the mounting groove, and the filler 213 fills the gap in the mounting groove.

[0056] Because the permanent magnet 212 is brittle and has low tensile strength, it is subjected to enormous centrifugal stress when the flywheel rotor 210 rotates at high speed. In this embodiment, a protrusion 211 is provided on the end face of the flywheel rotor 210 to form a mounting groove. The permanent magnet 212 is mounted in the mounting groove by abutting against the inner wall of the protrusion 211, and is fixed by a filler 213. This generates compressive stress on the permanent magnet 212, thereby reducing the centrifugal or internal stress on it and preventing damage due to stress overload, thus improving the operational safety of the flywheel energy storage device.

[0057] Specifically, filler 213 is an epoxy resin filler.

[0058] In an optional embodiment, such as Figure 6 and Figure 7 As shown, the rotor assembly 200 also includes a first bearing 230 and a second bearing 240. The first end cover 120 is provided with a first mounting seat 122, the first bearing 230 is disposed on the first mounting seat 122, one end of the rotating shaft 220 is mounted on the first bearing 230, the second end cover 130 is provided with a second mounting seat 131, the second bearing 240 is disposed on the second mounting seat 131, and the other end of the rotating shaft 220 is mounted on the second bearing 240.

[0059] In this embodiment, the first bearing 230 is precisely positioned by the first mounting base 122 of the first end cover 120, and the second bearing 240 is precisely positioned by the second mounting base 131 of the second end cover 130. This provides symmetrical and stable two-point support for the rotating shaft 220, effectively dispersing the radial and axial loads on the rotating shaft 220 and the flywheel rotor 210, and avoiding overload on one end. Moreover, the first bearing 230 and the second bearing 240 significantly reduce the radial runout and sway of the rotating shaft 220 during high-speed rotation, ensuring the dynamic balance accuracy of the flywheel rotor 210, reducing aerodynamic losses and electromagnetic coupling deviations caused by the shaking of the rotating shaft 220, and improving the energy conversion efficiency of the flywheel energy storage device.

[0060] In an optional embodiment, the shaft 220 and the flywheel rotor 210 are integrally formed. This embodiment eliminates the assembly gaps, weak points, and stress concentration areas present when the shaft 220 and flywheel rotor 210 are separately connected, significantly improving the overall structural rigidity and resistance to centrifugal loads. It can withstand the enormous radial and axial forces generated during the high-speed rotation of the flywheel rotor 210, avoiding risks such as loosening or breakage at the connection points. Furthermore, it eliminates the need for subsequent maintenance and inspection of the connection points, significantly extending the service life and operational reliability of the rotor assembly 200. This provides a core structural guarantee for the stable energy storage and efficient energy release of the flywheel energy storage device under high-speed conditions.

[0061] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0062] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A flywheel energy storage device, characterized in that, include: The housing (100) has a receiving cavity (100A); the housing (100) includes a housing body (110) and a first end cap (120), the first end cap (120) is disposed on one end of the housing body (110), and the first end cap (120) has a snap-fit ​​portion (121). A rotor assembly (200) is disposed in the receiving cavity (100A). The rotor assembly (200) includes a flywheel rotor (210) and a rotating shaft (220). The flywheel rotor (210) is connected to the rotating shaft (220), and the rotating shaft (220) is rotatably connected to the housing (100). A stator assembly (300) is connected to the housing (100) and is movably disposed at one end of the rotor assembly (200). When the flywheel energy storage device is in a charging or discharging state, the stator assembly (300) is positioned at a charging / discharging position close to the end face of the flywheel rotor (210). When the flywheel energy storage device is in a standby operating state, the stator assembly (300) is positioned away from the flywheel rotor (210). The stator assembly (300) includes a stator (310) connected to the housing (100); the stator (310) has a circumferentially convex edge (312), and when the stator (310) is in the charging / discharging position, the convex edge (312) abuts against the snap-fit ​​portion (121); the stator assembly (300) also includes a first connector (330), and the end face of the stator (310) facing the first end cover (120) has a connecting member. The first end cap (120) has a first connecting hole (120A) in the groove (310A). When the flywheel energy storage device is in a charging or discharging state, one end of the first connector (330) passes through the first connecting hole (120A), and the other end of the first connector (330) abuts against the bottom of the groove (310A), so that the protruding edge (312) abuts against the snap-fit ​​part (121); the stator assembly (300) also includes a second connector (340), the... The stator (310) is provided with a second connecting hole (310B) on the end face facing the first end cover (120), and the first end cover (120) is provided with a third connecting hole (120B). When the flywheel energy storage device is in standby operation, one end of the second connector (340) is connected to the second connecting hole (310B), and the other end of the second connector (340) is connected to the third connecting hole (120B), so that the stator assembly (300) is set in the standby position.

2. The flywheel energy storage device according to claim 1, characterized in that: The stator assembly (300) further includes an armature winding (320). The stator (310) has a plurality of stator teeth (311) along the circumferential direction. The armature winding (320) is installed in the slot formed by two adjacent stator teeth (311).

3. The flywheel energy storage device according to claim 1, characterized in that: The housing (100) further includes a second end cap (130), which is disposed on the other end of the housing body (110). The housing body (110), the first end cap (120), and the second end cap (130) together form the receiving cavity (100A). One end of the rotating shaft (220) is installed on the first end cap (120), and the other end of the rotating shaft (220) is installed on the second end cap (130). The stator assembly (300) is movably disposed between the flywheel rotor (210) and the first end cap (120).

4. The flywheel energy storage device according to claim 1, characterized in that: The snap-fit ​​part (121) is an L-shaped cross-section ring, and the snap-fit ​​part (121) is connected to the end of the first end cap (120) facing the receiving cavity (100A).

5. The flywheel energy storage device according to claim 1, characterized in that: The first connector (330) and the hole wall of the first connecting hole (120A) are connected by a first threaded pair.

6. The flywheel energy storage device according to claim 1, characterized in that: The second connector (340) includes a bolt and a nut, the bolt being sequentially inserted through a second connecting hole (310B) and a third connecting hole (120B), and the nut being connected to the end of the bolt that passes through the third connecting hole (120B).

7. The flywheel energy storage device according to claim 1, characterized in that: The third connecting hole (120B) and the second connecting hole (310B) include four holes. The four third connecting holes (120B) are equally spaced along the circumference of the first end cover (120), and the four second connecting holes (310B) are arranged along the circumference of the stator (310) corresponding to the four third connecting holes (120B).

8. The flywheel energy storage device according to claim 7, characterized in that: The second connector (340) includes a bolt and a nut, the bolt being sequentially inserted through the second connecting hole (310B) and the third connecting hole (120B), and the nut being connected to the end of the bolt that passes through the third connecting hole (120B).

9. The flywheel energy storage device according to claim 3, characterized in that: The rotor assembly (200) further includes a first bearing (230) and a second bearing (240). The first end cover (120) is provided with a first mounting seat (122). The first bearing (230) is disposed on the first mounting seat (122). One end of the rotating shaft (220) is mounted on the first bearing (230). The second end cover (130) is provided with a second mounting seat (131). The second bearing (240) is disposed on the second mounting seat (131). The other end of the rotating shaft (220) is mounted on the second bearing (240).

10. The flywheel energy storage device according to any one of claims 1-9, characterized in that: The flywheel rotor (210) has a protrusion (211) on its end face facing the stator assembly (300). The protrusion (211) forms a mounting groove around the circumference. The flywheel rotor (210) also includes a permanent magnet (212) and a filler (213). The permanent magnet (212) is arranged around the mounting groove, and the filler (213) fills the gap in the mounting groove.

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