Magnetic steel embedded rotor assembly, motor and fan assembly

Abstract

The application provides a magnetic steel embedded rotor assembly, a motor and a fan assembly, wherein the rotor assembly comprises a rotating shaft and a rotor core sleeved on the rotating shaft, the rotating shaft has an assembly shaft section and a support shaft section, the assembly shaft section is a part corresponding to the rotor core on the rotating shaft, the support shaft section is a part on the rotating shaft outside the assembly shaft section, the diameter of the assembly shaft section is smaller than that of the support shaft section, the annular gap between the rotor core and the assembly shaft section has a damping ring, and the rotor core and the assembly shaft section can be connected into one through the damping ring. Under the same outer diameter of the rotor core, the radial length of the rotor core can be larger, the radial size of the magnetic steel assembled thereon can be larger, that is, the amount of the magnetic steel on the rotor core can be increased, thereby the overall performance of the rotor assembly can be improved, and the radial thickness of the damping ring can be larger. The damping ring with larger thickness can also improve the damping effect of the rotor assembly.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of motor design, and particularly relates to a magnetic steel embedded rotor assembly, a motor and a fan assembly. BACKGROUND

[0002] In a permanent magnet motor, noise problems are concerned by everyone. Some noise sources are that motor excitation excites the blade mode to vibrate, thereby generating noise. Once the blade mode, that is, the inherent frequency of the blade, is designed, it is difficult to change. In order to isolate the motor excitation from exciting the blade mode or reduce the transmission of the motor excitation, damping material (damping) is usually added to the rotor. The damping material can effectively reduce the transmission and reduce the rotation fluctuation of the rotor. There are two kinds of fan damping rotors: one is a surface-mounted damping rotor ( Figure 1 ), and the other is an embedded damping rotor ( Figure 2 ).

[0003] The surface-mounted damping rotor is as shown in Figure 1 . The magnetic shoe is pasted on the outer periphery of the iron core. The internal space of the iron core is large, the space that can be filled by the damping material is large, and the damping effect is good. However, the overall power density of the surface-mounted rotor is low, and it is no longer favored by the market.

[0004] The embedded damping rotor is as shown in Figure 2 . The magnetic steel is embedded in the rotor iron core. The power density of this kind of rotor is greater than that of the surface-mounted damping rotor, and it is also the rotor scheme selected by major manufacturers in the market. However, this kind of rotor also has obvious defects:

[0005] 1. It can be known that the rotor assembly is installed in the motor, that is, the rotor needs to be inserted into the shaft and then other parts such as bearings to make the rotor assembly. The rotor is inserted into the shaft by a tool against the inner iron core, and a press is used to press the rotating shaft into the rotor iron core. Therefore, the inner iron core cannot be too small, otherwise it cannot withstand the great pressure of the press, which causes the iron core to deform and affects the concentricity of the rotor. Usually, the outer diameter size Rb of the inner iron core is about 1.6 times or more than the diameter Rz of the rotating shaft. At the same time, the inner iron core also needs to have a protrusion, which is generally used to limit the circumferential rotation of the rotor during rotation. The damping material is filled between the inner iron core and the outer iron core. Because the damping material also needs a certain thickness, the inner iron core and the damping material together limit the minimum inner diameter of the outer iron core. This structure further limits the length of the magnetic shoe in the radial direction, resulting in a reduction in the power density of the rotor.

[0006] 2. When the overall height of the rotor is not high enough, the amount of damping material is also small, and the damping effect of the damping rotor is not good enough.

[0007] 3. In the rotor with high shear strength, the existing scheme increases the height of the inner iron core of the rotor and further increases the damping material. However, the inner iron core and the outer iron core have no mutual force, and the shear strength that can be borne is still not guaranteed.

[0008] 4. The segmented vibration damping rotor is difficult to manufacture. The outer iron core is completely separated and fixed by relevant positioning posts. During injection molding, each iron core bears the pressure of the flowing material, which will result in a slightly poorer roundness of the rotor, leading to some new noise problems.

[0009] 5. The installation of the segmented vibration-damping rotor core involves more steps and incurs higher processing costs. Summary of the Invention

[0010] Therefore, the present invention provides a magnet-embedded rotor assembly, motor, and fan assembly, which can solve the technical problem in the prior art where the radial dimension of the embedded magnet is too small due to unreasonable design of the iron core vibration reduction structure, resulting in a small amount of magnet used in the rotor assembly and low rotor performance of the motor.

[0011] To address the aforementioned problems, the present invention provides a magnet-embedded rotor assembly, comprising a rotating shaft and a rotor core fitted onto the rotating shaft.

[0012] The rotating shaft has an assembly shaft section and a support shaft section. The assembly shaft section is the part of the rotating shaft corresponding to the rotor core. The support shaft section is the part of the rotating shaft outside the assembly shaft section. The diameter of the assembly shaft section is smaller than the diameter of the support shaft section. A vibration damping ring is provided in the annular gap between the rotor core and the assembly shaft section. The rotor core and the assembly shaft section can be connected via the vibration damping ring.

[0013] In some implementations...

[0014] The outer circumferential wall of the assembly shaft section has a circumferential limiting structure.

[0015] In some implementations...

[0016] The circumferential limiting structure includes ribs or patterns protruding from the outer circumferential wall of the assembly shaft section.

[0017] In some implementations...

[0018] An inner limiting sleeve is fitted onto the assembly shaft section. The inner limiting sleeve includes a sleeve and multiple protrusions on the outer circumferential wall of the sleeve, extending radially outward along the inner limiting sleeve. The multiple protrusions extend axially along the rotating shaft. The diameter of the outer circumferential wall of the sleeve is not greater than the diameter of the support shaft section. The vibration damping ring is located in the gap between the sleeve and the rotor core.

[0019] In some implementations...

[0020] The number of the inner limiting sleeves is one, and the length of the inner limiting sleeve is equal to the length of the assembly shaft segment; or, the number of the inner limiting sleeves is at least two, and each inner limiting sleeve is arranged in sequence and closely adjacent along the length of the assembly shaft segment.

[0021] In some embodiments,

[0022] The rotor core comprises a plurality of axially stacked core laminations, the core laminations comprising a core inner ring and a plurality of core segments extending radially outward from the outer wall of the core inner ring, and a magnetic steel slot is formed between two adjacent core segments along the radial direction of the core inner ring, and a magnetic steel assembly is positioned in the magnetic steel slot.

[0023] In some embodiments,

[0024] The inner wall of the core inner ring has a plurality of protrusions, and the protrusions are uniformly spaced along the circumferential direction of the core inner ring, and each protrusion intersects with each protrusion in the circumferential direction of the shaft.

[0025] In some embodiments,

[0026] The magnetic steel embedded rotor assembly further comprises a plurality of stack height adjustment rings, and each stack height adjustment ring can be stacked integrally along the axial direction of the shaft and connected to the end face of the core inner ring.

[0027] In some embodiments,

[0028] One side of the stack height adjustment ring has a plurality of first buckle point protrusions, and the back of each first buckle point protrusion is a first buckle point groove, and one side of the core inner ring has a plurality of second buckle point protrusions, and the back of each second buckle point protrusion is a second buckle point groove, and each core lamination is axially stacked by adjacent and corresponding second buckle point protrusions and second buckle point grooves, and each stack height adjustment ring is axially stacked by adjacent and corresponding first buckle point protrusions and first buckle point grooves, and the first buckle point groove of the adjacent stack height adjustment ring is connected to the second buckle point protrusion of the core inner ring.

[0029] In some embodiments,

[0030] The outer wall of the core inner ring also has a magnetic steel inner side positioning protrusion, each magnetic steel inner side positioning protrusion is between two adjacent core segments, and each magnetic steel slot has two oppositely spaced magnetic steel outer side positioning protrusions at the slot opening, and the magnetic steel outer side positioning protrusions are on the core segments.

[0031] In some embodiments,

[0032] The inner limiting sleeve is injection molded.

[0033] In some implementations...

[0034] The vibration damping ring is formed by rubber injection molding; and / or, the outer circumferential surface of the rotor core has a plastic coating layer.

[0035] The present invention also provides an electric motor, including the above-described magnet-embedded rotor assembly.

[0036] The present invention also provides a fan assembly, including the motor described above.

[0037] This invention provides a magnet-embedded rotor assembly, motor, and fan assembly. Because the diameter of the assembly shaft section is smaller than the diameter of the supporting shaft section of the rotor shaft, after the rotor core is connected to the assembly shaft section by a vibration damping ring, the radial length of the rotor core can be larger for the same outer diameter. The radial dimension of the magnets assembled on it can be larger, which means that the amount of magnets on the rotor core can be increased, thereby improving the overall performance of the rotor assembly. At the same time, the radial thickness of the vibration damping ring can also be set to be larger, and a thicker vibration damping ring can also improve the vibration damping effect of the rotor assembly. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of a surface-mount vibration-damping rotor in the prior art;

[0039] Figure 2 This is a schematic diagram of the structure of an embedded vibration damping rotor in the prior art;

[0040] Figure 3 This is an exploded view of the structure of the magnet-embedded rotor assembly according to an embodiment of the present invention;

[0041] Figure 4 for Figure 3 The diagram shows the assembly structure of the magnet-embedded rotor assembly.

[0042] Figure 5 for Figure 3 A partial structural diagram of the rotating shaft in the diagram;

[0043] Figure 6 for Figure 3 A three-dimensional structural diagram of the inner limiting sleeve;

[0044] Figure 7 for Figure 3 A three-dimensional structural diagram of the rotor core in the image;

[0045] Figure 8 for Figure 3 A three-dimensional structural diagram of one side of the stacking adjustment ring;

[0046] Figure 9 is Figure 3 another side of the height-adjusting ring in

[0047] The reference signs are indicated as:

[0048] 1, rotating shaft; 11, assembled shaft section; 12, axial displacement limiting groove; 2, rotor core; 21, core inner ring; 211, magnetic steel inner side positioning protrusion; 212, magnetic steel outer side positioning protrusion; 22, core block; 23, magnetic steel slot; 24, magnetic steel; 25, protrusion; 251, second buckling point protrusion; 3, damping ring; 4, inner limiting sleeve; 41, sleeve; 42, convex strip; 5, height-adjusting ring; 51, first buckling point protrusion; 52, first buckling point groove; 6, plastic coating layer. DETAILED DESCRIPTION

[0049] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0050] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0051] Reference should be made to Figure 3 and Figure 9As shown, according to the embodiment of the present application, a magnetic steel embedded rotor assembly is provided, which comprises a rotating shaft 1 and a rotor core 2 sleeved on the rotating shaft 1, the rotating shaft 1 has an assembly shaft section 11 and a support shaft section, the assembly shaft section 11 is the part of the rotating shaft 1 corresponding to the rotor core 2, the support shaft section is the part of the rotating shaft 1 outside the assembly shaft section 11, the diameter of the assembly shaft section 11 is smaller than that of the support shaft section, the annular gap between the rotor core 2 and the assembly shaft section 11 has a damping ring 3, and the rotor core 2 and the assembly shaft section 11 can be connected as a whole through the damping ring 3, the connection as a whole includes direct connection as a whole or indirect connection as a whole, and it should be noted that the support shaft section can be provided with an axial displacement limiting groove 12 based on the axial positioning of the sleeving component on the rotating shaft 1, such as the aforementioned rotor core 2, at this time the groove bottom diameter of the axial displacement limiting groove 12 is not the diameter of the aforementioned support shaft section, and the aforementioned support shaft section is specifically supported by the bearings at both ends of the rotating shaft 1.

[0052] Specifically referring to Figure 5 As shown, the aforementioned assembly shaft section 11 is formed based on the machining of the rotating shaft 1, that is, the material removal processing is performed between the two bearing positions of the rotating shaft, and the material removal thickness has no fixed requirement, as long as it is not less than the strength requirement of the rotating shaft and has stepped surfaces on both sides; the material removal starting position L depends on the size of the traditional rotor shaft, and the material removal length H is determined according to the designed damping length.

[0053] In this technical solution, since the diameter of the assembly shaft section 11 is smaller than that of the support shaft section of the rotating shaft 1, after the rotor core 2 is connected as a whole with the assembly shaft section 11 through the damping ring 3, under the same outer diameter size of the rotor core 2, the radial length of the rotor core 2 can be larger, the radial size of the magnetic steel 24 assembled thereon can be larger, that is, the amount of magnetic steel on the rotor core 2 can be increased, thereby the overall performance of the rotor assembly can be improved, and at the same time, the radial thickness of the damping ring 3 can also be larger, and the damping ring 3 with larger thickness can also improve the damping effect of the rotor assembly.

[0054] In some embodiments,

[0055] The outer circumferential wall of the assembly shaft section 11 has a circumferential limiting structure, which has the ability to limit the circumferential movement, and specifically, the circumferential limiting structure includes ribs or patterns protruding from the outer circumferential wall of the assembly shaft section 11, that is, the circumferential limiting structure can be formed by performing ribbing or knurling processing on the surface of the material-removed rotating shaft.

[0056] In a preferred embodiment, specifically referring to Figure 6As shown, an inner limiting sleeve 4 is fitted on the assembly shaft section 11. The inner limiting sleeve 4 includes a sleeve 41 and multiple protrusions 42 on the outer circumferential wall of the sleeve 41 and extending radially outward along the inner limiting sleeve 4. The multiple protrusions 42 extend axially along the rotating shaft 1. The diameter of the outer circumferential wall of the sleeve 41 is not greater than the diameter of the supporting shaft section. The vibration damping ring 3 is located in the gap between the sleeve 41 and the rotor core 2.

[0057] In this technical solution, the sleeve 41 of the inner limiting sleeve 4 forms a reliable connection with the aforementioned assembly shaft section 11, and the radially outwardly extending protrusion 42 achieves a reliable connection with the vibration damping ring 3, ensuring a reliable vibration damping connection between the rotating shaft 1 and the rotor core 2, thereby ensuring the vibration damping effect.

[0058] In some embodiments, the number of inner limiting sleeves 4 can be one, and the length of one inner limiting sleeve 4 is equal to the length of the assembly shaft segment 11; or, the number of inner limiting sleeves 4 can be at least two, and each inner limiting sleeve 4 is arranged adjacent to each other along the length of the assembly shaft segment 11. The use of inner limiting sleeves 4 can be flexibly selected according to actual needs, so that it can be applied to assembly shaft segments 11 with different axial lengths.

[0059] The material of the inner limiting sleeve 4 is not limited; it can be either metallic or non-metallic. When it is metallic, it can be welded; when it is non-metallic, it can be assembled into a single unit using a snap-fit ​​method. Preferred material is injection molding, which allows for easy connection to the assembly shaft section 11 and offers relatively lower manufacturing costs. Direct injection molding of the inner limiting sleeve 4 integrates it with the rotating shaft, and its outer diameter is made to be the same as the shaft diameter, equivalent to a traditional inner iron core. Figure 2 The outer diameter Rb of the ring is made to be equal to the shaft diameter Rz, which directly saves 0.6 times the length. (For example, with a shaft diameter of 12mm as the benchmark, 7.2mm of length can be saved.) This increases the space left for the damping ring 3, rotor core 2, and magnet 24 by 0.6 times, allowing the radial length of magnet 24 to be maximized.

[0060] Taking the case where the diameter of the outer circumferential wall of the sleeve 41 of the inner limiting sleeve 4 is equal to the diameter of the support shaft section as an example, in the traditional embedded vibration damping rotor, the shaft diameter is 12mm, so the outer diameter of the inner iron core ring needs to be greater than 18mm to ensure the support and strength of the shaft tooling. However, the present invention can make the outer diameter of the sleeve 41 of the inner limiting sleeve 4 the same as the shaft diameter, that is, the shaft diameter is 12mm. The outer diameter of the sleeve 41 of the inner limiting sleeve 4 can be 12mm, which is equivalent to saving 33.3% of the space.

[0061] See Figure 7 As shown, in some implementations,

[0062] The rotor core 2 comprises a plurality of axially stacked core laminations, the core laminations comprising a core inner ring 21 and a plurality of core segments 22 extending radially outward from the outer wall of the core inner ring 21, a magnetic steel slot 23 being formed between two adjacent core segments 22 along the radial direction of the core inner ring 21, and a magnetic steel 24 being assembled in the magnetic steel slot 23.

[0063] In the technical solution, each core segment 22 is connected to form a whole through the core inner ring 21, so that the roundness of the rotor is ensured. It can be understood that the radial thickness of the core inner ring 21 should be designed to be relatively small to reduce the magnetic leakage. Compared with the conventional segmented outer rotor core, the core inner ring 21 in the present application is used to connect the core segments 22 to form a whole, so that the number of assembly parts is reduced, the assembly process steps are reduced, and the manufacturing cost is reduced.

[0064] Referring back to Figure 7 In some embodiments,

[0065] The core inner ring 21 has a plurality of protrusions 25 on the inner wall thereof, the plurality of protrusions 25 being uniformly spaced along the circumferential direction of the core inner ring 21, and each protrusion 25 intersects with each protrusion 42 in the circumferential direction of the rotating shaft 1. The protrusions 25 and the protrusions 42 form a zigzag annular gap structure, and when the damping ring 3 is injection molded in the annular gap structure, more bonding area is provided to ensure reliable connection of the rotor core 2, the inner limiting sleeve 4 and the damping ring 3, prevent loosening caused by long-time operation of the rotor assembly, and improve the service life of the rotor assembly.

[0066] Referring back to Figure 1 , Figure 8 and Figure 9 In some embodiments,

[0067] The magnetic steel embedded rotor assembly further comprises a plurality of stack height adjusting rings 5, each stack height adjusting ring 5 being capable of being stacked in a whole along the axial direction of the rotating shaft 1 and being connected to the end face of the core inner ring 21, and the number of the stack height adjusting rings 5 is selected according to actual needs.

[0068] In the technical solution, the connection of the stack height adjusting ring 5 can increase the relative position between the rotor core 2 and the inner limiting sleeve 4, so that more damping ring 3 material can be injection molded therebetween, which can increase the shear resistance of the damping rotor, the damping material can be improved according to actual needs, and the damping effect can be ensured. The stack height adjusting ring 5 matches the core inner ring 21 of the rotor core 2 in the overall structure, that is, it does not need to match the shape of the laminations of the entire rotor core 2, so that unnecessary waste is not increased.

[0069] In one specific embodiment, referring back toFigure 8 and Figure 9 as shown in the drawings,

[0070] The side surface of the stack height adjusting ring 5 has a plurality of first buckling point protrusions 51, the back surface of each first buckling point protrusion 51 is a first buckling point groove 52, the side surface of the inner core ring 21 has a plurality of second buckling point protrusions 251, the back surface of each second buckling point protrusion 251 is a second buckling point groove, each core punching piece is axially stacked through adjacent and corresponding second buckling point protrusions 251 and second buckling point grooves, and each stack height adjusting ring 5 is axially stacked through adjacent and corresponding first buckling point protrusions and first buckling point grooves, and the first buckling point grooves 52 of adjacent stack height adjusting rings 5 are buckled and connected with the second buckling point protrusions 251 of the inner core ring 21.

[0071] In the technical solution, the first buckling point protrusions 51, the first buckling point grooves 52, the second buckling point protrusions 251, and the second buckling point grooves can be formed by stamping, which is a mature technology and can simplify the connection structure of each component.

[0072] In some embodiments,

[0073] The outer ring wall of the inner core ring 21 also has a plurality of magnetic steel inner side positioning protrusions 211, each magnetic steel inner side positioning protrusion 211 is between two adjacent core blocks 22, and each magnetic steel slot 23 has two magnetic steel outer side positioning protrusions 212 arranged opposite to each other at the slot opening, and the magnetic steel outer side positioning protrusions 212 are on the core blocks 22.

[0074] In the technical solution, the magnetic steel inner side positioning protrusions 211 and the magnetic steel outer side positioning protrusions 212 reliably position the magnetic steel 24 in the magnetic steel slot 23 in the radial direction, preventing the magnetic steel 24 from moving in the radial direction in the magnetic steel slot 23 during operation of the rotor assembly. It can be understood that the circumferential displacement of the magnetic steel 24 is limited by the two circumferential slot walls of the magnetic steel slot 23.

[0075] In a specific embodiment, the damping ring 3 is formed by rubber injection molding.

[0076] As a preferred implementation, the outer circumferential surface of the rotor core 2 has a plastic coating layer 6, that is, the rotor core 2 of the rotor assembly of the application is preferably packaged with a plastic coating material, which specifically wraps the rotor core 2, the magnetic steel 24, and the inner limiting sleeve 4 of the application as a whole, making the structure of the entire rotor assembly more compact.

[0077] According to the embodiment of the present application, a motor is also provided, which comprises the above-mentioned magnetic steel embedded rotor assembly. The magnetic steel embedded rotor assembly is used in the motor. Since the diameter of the assembly shaft segment 11 is smaller than that of the support shaft segment of the rotating shaft 1, after the rotor core 2 is connected with the assembly shaft segment 11 through the damping ring 3, the radial length of the rotor core 2 can be larger under the same outer diameter of the rotor core 2, and the radial size of the magnetic steel 24 assembled thereon can be selected to be larger, that is, the amount of the magnetic steel on the rotor core 2 can be increased, and thus the overall performance of the rotor assembly can be improved. Meanwhile, the radial thickness of the damping ring 3 can also be set to be larger, and the damping ring 3 with larger thickness can also improve the damping effect of the rotor assembly.

[0078] According to the embodiment of the present application, a fan assembly is also provided, which comprises the above-mentioned motor.

[0079] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0080] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A magnetic steel embedded rotor assembly, comprising a rotating shaft (1) and a rotor core (2) sleeved on the rotating shaft (1), characterized in that, the rotating shaft (1) has an assembly shaft section (11) corresponding to the rotor core (2) and a support shaft section, the assembly shaft section (11) has a smaller diameter than the support shaft section, an annular gap is formed between the rotor core (2) and the assembly shaft section (11), and a damping ring (3) is arranged in the annular gap, the rotor core (2) and the assembly shaft section (11) are connected via the damping ring (3); the assembly shaft section (11) is sleeved with an inner limiting sleeve (4), the inner limiting sleeve (4) comprises a sleeve (41) and a plurality of protrusions (42) extending outward along the radial direction of the inner limiting sleeve (4) on the outer circumferential wall of the sleeve (41), the plurality of protrusions (42) extend along the axial direction of the rotating shaft (1), the diameter of the outer circumferential wall of the sleeve (41) is not greater than the diameter of the support shaft section, and the damping ring (3) is arranged in the gap between the sleeve (41) and the rotor core (2).

2. The magnetic steel embedded rotor assembly according to claim 1, characterized in that, the outer circumferential wall of the assembly shaft section (11) has a circumferential limiting structure.

3. The magnetic steel embedded rotor assembly according to claim 2, characterized in that, the circumferential limiting structure comprises ribs or patterns protruding from the outer circumferential wall of the assembly shaft section (11).

4. The magnetic steel embedded rotor assembly according to claim 1, characterized in that, the number of the inner limiting sleeve (4) is one, and the length of the inner limiting sleeve (4) is equal to the length of the assembly shaft section (11); or the number of the inner limiting sleeve (4) is at least two, and each inner limiting sleeve (4) is arranged in sequence and adjacent to each other along the length of the assembly shaft section (11).

5. The magnetic steel embedded rotor assembly according to claim 1, characterized in that, the rotor core (2) comprises a plurality of axially stacked core punches, the core punch comprises a core inner ring (21) and a plurality of core blocks (22) extending outward along the radial direction of the core inner ring (21) on the outer wall of the core inner ring (21), a magnetic steel slot (23) extending along the radial direction of the core inner ring (21) is formed between two adjacent core blocks (22), and a magnetic steel (24) is assembled in the magnetic steel slot (23).

6. The magnetic steel embedded rotor assembly according to claim 5, characterized in that, the inner wall of the core inner ring (21) has a plurality of protrusions (25), the plurality of protrusions (25) are uniformly and spacedly arranged along the circumferential direction of the core inner ring (21), and each protrusion (25) and each protrusion (42) cross each other in the circumferential direction of the rotating shaft (1).

7. The magnetic steel embedded rotor assembly according to claim 5, wherein a plurality of height adjustment rings (5) are further included, each of the height adjustment rings (5) being axially stacked and connected with an end surface of the inner core (21) of the rotor.

8. The magnetic steel embedded rotor assembly according to claim 7, wherein the height adjustment ring (5) has a plurality of first buckling point protrusions (51) on one side surface, each of the first buckling point protrusions (51) having a first buckling point recess (52) on a back surface, the inner core (21) has a plurality of second buckling point protrusions (251) on one side surface, each of the second buckling point protrusions (251) having a second buckling point recess on a back surface, each of the core punching sheets is axially stacked with each of the second buckling point protrusions (251) and the second buckling point recess, each of the height adjustment rings (5) is axially stacked with each of the first buckling point protrusions and the first buckling point recess, and the first buckling point recess (52) of each of the height adjustment rings (5) is connected with the second buckling point protrusion (251) of the inner core (21).

9. The magnetic steel embedded rotor assembly according to claim 5, wherein the inner core (21) further has a plurality of magnetic steel inner positioning protrusions (211) on an outer wall, each of the magnetic steel inner positioning protrusions (211) being between two adjacent core blocks (22), each of the magnetic steel slots (23) has two magnetic steel outer positioning protrusions (212) at a slot opening, and the magnetic steel outer positioning protrusions (212) are on the core blocks (22).

10. The magnetic steel embedded rotor assembly according to claim 4, wherein the inner limiting sleeve (4) is injection molded.

11. The magnetic steel embedded rotor assembly according to any one of claims 1 to 10, wherein the damping ring (3) is injection molded with rubber, and / or an outer circumferential surface of the rotor core (2) has a plastic coating (6). The magnetic steel embedded rotor assembly according to any one of claims 1 to 11. The electric machine according to claim 12. ​ ​ ​ 12. An electric machine characterized by ​ 13. A fan assembly comprising: ​

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