A motor rotor, a motor using the same and a range hood

Abstract

A motor rotor, a motor using the rotor and a kind of oil fume suction, a kind of motor rotor, characterized in that, the motor rotor includes: a plurality of sequentially laminated rotor core punching sheet, rotor core punching sheet includes inner rotor punching sheet and outer rotor punching sheet;Outer rotor core is also provided with magnetic steel slot along the circumferential direction at intervals;Magnetic steel assembly and filler;Wherein, the outer rotor punching sheet includes a plurality of outer rotor punching sheet units, adjacent outer rotor punching sheet units are independent and form the magnetic steel slot;The outer contour of each outer rotor punching sheet unit is the continuous arc line formed by the intersection of at least two eccentric circular arcs, and the center of each eccentric circular arc is eccentric with the center of the outer circle of the rotor core punching sheet.The utility model has the advantages that: multiple eccentric circular arc structure is adopted, the leakage magnetic quantity is greatly inhibited under the condition of guaranteeing output characteristic, the motor output torque characteristic is improved, high performance and good NVH characteristic are realized.

Description

Technical Field

[0001] This utility model relates to an electric motor rotor, and more particularly to an electric motor rotor, an electric motor using the rotor, and a range hood using the electric motor. Background Technology

[0002] In recent years, the performance requirements for range hoods have clearly shifted towards higher air pressure, larger air volume, and lower noise. As one of the core components of a range hood, the performance of the motor has a significant impact on the suction power, noise level, and lifespan of the product.

[0003] NVH performance refers to the noise, vibration, and harshness exhibited by a motor during operation. Currently, range hoods have high requirements for vibration and noise levels. However, the vibration and noise factors of electric motors are mainly concentrated in the rotor. Traditional electric motors suffer from problems such as high vibration, high noise, low efficiency, and high cost during use, resulting in a poor user experience.

[0004] In the prior art, Chinese utility model patent No. 201821213504.1, entitled "A Surface-Mounted Permanent Magnet Rotor Structure", Chinese invention patent No. 201210316633.4, entitled "An Embedded Sine-Shaped Permanent Magnet Motor Rotor", and Chinese utility model patent No. 201921367301.2, entitled "A Motor with a Vibration-Damping Mounting Base", respectively disclose motor rotors with three structures: surface-mounted, embedded, and vibration-damping. However, each rotor structure has its inherent defects.

[0005] Surface-mounted motor rotors can achieve high power, but the bonding is unreliable and the motor speed is limited; embedded motor rotors can achieve high speeds, but their load-bearing capacity is poor and the risk of abnormal noise is high; while vibration-damping motors can reduce motor vibration, the rotor strength is poor, which affects the service life and safety of the motor.

[0006] To address the compatibility issues in electric motor applications, the design process needs to strongly correlate motor output performance and NVH (noise, vibration, and harshness) performance. Therefore, optimizing the traditional rotor structure to address the aforementioned existing problems is extremely crucial. Utility Model Content

[0007] The first technical problem to be solved by this utility model is to provide a motor rotor that can effectively suppress leakage flux and improve the output torque characteristics of the motor while meeting the mechanical strength requirements of the rotor structure, in light of the above-mentioned existing technology.

[0008] The second technical problem to be solved by this utility model is to provide an electric motor with the above-mentioned rotor structure, which has low vibration and low noise, in view of the current state of the prior art.

[0009] The third technical problem to be solved by this utility model is to provide a range hood that uses the aforementioned electric motor, in view of the current state of the prior art.

[0010] The technical solution adopted by this utility model to solve the first technical problem mentioned above is: an electric motor rotor, characterized in that the electric motor rotor includes:

[0011] The rotor core assembly includes multiple rotor core laminations stacked sequentially. The rotor core laminations include inner rotor laminations and outer rotor laminations. The inner rotor laminations are stacked to form the inner rotor core, and the outer rotor laminations are stacked to form the outer rotor core. The inner rotor core has a shaft hole, the center of which is the center of the outer circle of the rotor core lamination. The outer rotor core is also provided with magnetic slots at intervals along the circumference.

[0012] The magnet assembly includes a magnet sheet that can be embedded in the magnet slot; and

[0013] Filler material used to fill the gap formed between the inner rotor core and the outer rotor core;

[0014] The outer rotor lamination includes multiple outer rotor lamination units arranged circumferentially around the inner rotor lamination. Adjacent outer rotor lamination units are independent of each other and form the magnetic slots. The outer contour of each outer rotor lamination unit is a continuous arc formed by the intersection of at least two eccentric arcs. The center of each eccentric arc is eccentrically set with respect to the center of the outer circle of the rotor core lamination.

[0015] Preferably, the rotor core assembly includes multiple rotor core laminations that are sequentially rotated n° and stacked, where n° = 360° / 2P, and 2P is the number of pole pairs. In this application, 2P is preferably 10, and n° is a rotation of 36°. The rotational stacking design can improve the rotor's dynamic imbalance and reduce the generation of modulation vibration.

[0016] As one preferred embodiment, the outer contour of the outer rotor lamination unit can be formed by the intersection of two eccentric circular arcs. These eccentric arcs can include a first eccentric arc and a second eccentric arc. The center of the first eccentric arc is set as O1, and its radius as R1. The center of the second eccentric arc is set as O2, and its radius as R2. The center of the outer circle of the rotor core lamination is set as O, and its radius as R. The centers O, O1, and O2 are all on the same straight line, and the eccentricity of center O1 relative to circle O is L1, the eccentricity of center O2 relative to center O1 is L2, and R2 + L1 + L2 > R. In this embodiment, the three points O, O1, and O2, when connected, are all on the same straight line and are arranged radially along the outer circle of the rotor core lamination.

[0017] As another preferred embodiment, the outer contour of the outer rotor lamination unit can be formed by the intersection of three eccentric circular arcs. The eccentric circular arcs include a third eccentric circular arc, a fourth eccentric circular arc, and a fifth eccentric circular arc. The center of the third eccentric circular arc is set to O3, and the radius of the third eccentric circular arc is set to R3; the center of the fourth eccentric circular arc is set to O4, and the radius of the fourth eccentric circular arc is set to R4; the center of the fifth eccentric circular arc is set to O5, and the radius of the fifth eccentric circular arc is set to R; the center of the outer circle of the rotor core lamination is set to O, and the radius of the outer circle of the rotor core lamination is set to R.

[0018] The fourth and fifth eccentric arcs are symmetrically arranged on both sides of the third eccentric arc. The eccentricity of the center O3 relative to the circle O is L3, the eccentricity of the center O4 relative to the center O3 is L4, and the eccentricity of the center O5 relative to the center O3 is L5. R4+L3+L4>R, R5+L3+L5>R, and R4=R5, L4=L5.

[0019] In this scheme, the line connecting the centers O and O3 is set along the radial direction of the outer circle of the rotor core lamination. However, the lines connecting the centers O4 and O3, as well as the lines connecting the centers O5 and O3, are deviated from the radial direction of the outer circle of the rotor core lamination. Furthermore, the three points O, O3, and O4, or the three points O, O3, and O5, are not on the same straight line after they are connected.

[0020] To ensure that the output torque meets requirements while effectively controlling the air gap magnetic flux density and improving the back electromotive force waveform, preferably, each of the outer rotor lamination units is fan-shaped. The larger end of each outer rotor lamination unit extends to both sides to form a magnet positioning section that narrows from wide to narrow. Using the narrowest extension line of this magnet positioning section as a reference line, the height ratios obtained after the two eccentric arcs intersect this reference line are h and H, respectively, where h ≥ 1 / 2H. Therefore, the larger h is, the smaller the output torque, the smaller the harmonic amplitude of each order of the air gap magnetic flux density, and the lower the distortion rate. Thus, a reasonable design of the eccentric arcs can ensure that the output torque meets requirements while effectively improving the low-order harmonic content and sinusoidal waveform of the air gap magnetic field.

[0021] Preferably, the inner rotor lamination and the outer rotor lamination are connected by at least one partition bridge along the circumferential direction. The partition bridge structure connects the toothed portion and the yoke portion, and the partition bridge structure fully considers the magnetic field distribution and the direction of magnetic field lines, which can reduce or avoid leakage magnetic field and improve performance.

[0022] Considering processing costs and difficulties, as a further preferred option, there are m partition bridges, where m ranges from X / 2, and X represents the number of pole pairs. The partition bridges are arranged along the circumference, spaced one outer rotor lamination unit apart. In this embodiment, the number of pole pairs is 10, therefore the number of partition bridges is 5. Each partition bridge passes through the center of the outer rotor lamination and is arranged radially. Not every tooth and yoke needs a partition bridge. Where partition bridges are not used, the magnetic resistance of the yoke leakage magnetic circuit can be increased, thereby reducing leakage magnetic flux and improving performance. Where partition bridges are used, the connection strength between the tooth and yoke can be further strengthened, preventing separation and thus improving assembly accuracy.

[0023] Preferably, the inner rotor lamination is circular, and spaced-apart positioning bosses are formed along its outer periphery, with adjacent positioning bosses forming the yoke of the rotor assembly. This positioning boss design facilitates the installation and positioning of the magnet sheets, improves assembly consistency, enhances packaging flow, thereby improving packaging quality and further strengthening the structure.

[0024] As a further preferred embodiment, each of the outer rotor lamination units is fan-shaped, and the small end of the fan-shaped part of each outer rotor lamination unit forms a tooth, which corresponds to the yoke of the inner rotor lamination. A partition bridge is provided between the tooth of at least one set of corresponding outer rotor lamination units and the yoke of the inner rotor lamination.

[0025] Preferably, the inner rotor lamination is further provided with spaced-apart first self-locking holes for connecting adjacent stacked inner rotor laminations along the circumferential direction. The slot direction of the first self-locking holes is along the circumferential direction of the inner rotor lamination. The inner rotor lamination adopts a tangential rectangular self-locking structure, and the self-locking direction is consistent with the magnetic circuit, which can reduce the magnetic resistance generated by self-locking.

[0026] Preferably, each of the outer rotor lamination units is provided with a second self-locking hole for connecting adjacent stacked outer rotor laminations; the groove direction of the second self-locking hole is along the radial direction of the outer rotor lamination. The radial rectangular self-locking structure on the outer rotor lamination can reduce the radial displacement generated when the lamination assembly is inserted into the central through hole, thereby avoiding changes in the size of the magnet slot.

[0027] To increase the mechanical strength of the laminations, preferably, each of the outer rotor lamination units is also provided with an auxiliary circular self-locking mechanism to increase the mechanical strength of the laminations.

[0028] Preferably, each of the outer rotor lamination units is also provided with process holes that allow for fluid venting. These process holes enable fluid venting during the filling process, enhancing the density of the filler and simultaneously increasing the mechanical strength of the rotor assembly.

[0029] Preferably, the cross-section of the magnet sheet is trapezoidal. The length of the upper base of the trapezoidal cross-section is set as d1, and the length of the lower base is set as d2, where d1 / d2 = λ, 0 < λ ≤ 1. Therefore, the larger λ is, the greater the average output torque of the motor, and the greater the cogging torque and pulsating torque. By designing the upper and lower bases of the magnet sheet to be unequal, the cogging torque and pulsating torque can be optimized, improving NVH characteristics.

[0030] The technical solution adopted by this utility model to solve the second technical problem mentioned above is: an electric motor, including a rotor and a stator, characterized in that: the rotor is an electric motor rotor as described above.

[0031] The technical solution adopted by this utility model to solve the third technical problem mentioned above is: a range hood, including a casing, a fan and an electric motor that drives the fan to rotate, characterized in that: the electric motor is the electric motor described above.

[0032] Compared with existing technologies, the advantages of this invention are as follows: It employs a multi-eccentric circular arc structure to design the outer contour of the motor rotor, which greatly suppresses leakage flux and improves the motor's output torque characteristics while ensuring output characteristics. Simultaneously, it effectively improves the air gap magnetic field and back electromotive force waveform, achieving high performance and excellent NVH characteristics. Furthermore, the embedded magnets within the rotor core allow for integrated encapsulation, enhancing the rotor's mechanical strength. The manufacturing process is simple, highly operable, and can reduce manufacturing costs to some extent. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the planar structure of the motor rotor core laminations according to an embodiment of the present invention.

[0034] Figure 2This is a three-dimensional structural diagram of the motor rotor core assembly according to an embodiment of the present utility model.

[0035] Figure 3 This is a schematic diagram of the three-dimensional structure of the filler material according to an embodiment of the present utility model.

[0036] Figure 4 This is a schematic diagram of the three-dimensional structure of the magnet in an embodiment of the present invention.

[0037] Figure 5 This is a side view of the magnet in an embodiment of the present utility model.

[0038] Figure 6 This is a cross-sectional view of the assembly plane of the motor rotor core according to an embodiment of the present utility model.

[0039] Figure 7 This is a three-dimensional structural diagram of the motor rotor core according to an embodiment of the present invention.

[0040] Figure 8 This is a schematic diagram of the eccentric structure of the outer contour arc of the motor rotor core lamination in an embodiment of the present invention (the line connecting the centers of the two eccentric arcs is collinear with the center of the shaft hole).

[0041] Figure 9 for Figure 8 The diagram shows a partially enlarged structural schematic of part I.

[0042] Figure 10 This utility model provides a schematic diagram of the eccentric structure of the outer contour arc of the motor rotor core lamination (the line connecting the centers of the two eccentric arcs is not collinear with the center of the shaft hole). Detailed Implementation

[0043] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0044] This embodiment discloses a range hood, which includes a casing, a fan, and an electric motor that drives the fan to rotate. The electric motor includes a rotor and a stator, and the rotor adopts a... Figures 1-10 The motor rotor structure shown is implemented.

[0045] like Figure 6 , Figure 7 As shown, the motor rotor of this embodiment includes a rotor core assembly 1, a magnet assembly, and a filler 3. The magnet assembly includes magnet sheets 2 that can be embedded in the magnet slots 13. The filler 3 is used to fill the gap formed between the inner rotor core and the outer rotor core. See [link to documentation]. Figure 3 ;

[0046] The rotor core assembly 1 includes multiple rotor core laminations stacked sequentially. The thickness of each rotor core lamination is approximately 0.1-1mm. Each rotor core lamination is rotated n° clockwise (or counterclockwise) in the same direction and then self-clamped. The rotation angles of the rotor core laminations between each other are independent and are all n°. After the previous lamination rotates n°, the next lamination is rotated n° in the same direction on the basis of the previous lamination and then stacked. This process is repeated until the required rotor core is formed according to the design stacking height requirements. The rotation angle can be determined according to the number of pole pairs. The rotation angle is 360° / P, where 2P is the number of pole pairs. In this scheme, 2P is preferably 10, and n° rotation is 36. The rotation stacking design can improve the dynamic imbalance of the rotor and reduce the generation of modulation vibration.

[0047] Specifically, the rotor core laminations include inner rotor laminations 11 and outer rotor laminations. The inner rotor laminations 11 are stacked to form the inner rotor core, and the outer rotor laminations are stacked to form the outer rotor core. The inner rotor core has a shaft hole 111, the center of which is the center of the outer circle of the rotor core lamination. The outer rotor core is also provided with magnetic slots 13 at intervals along the circumference. See [reference needed]. Figure 1 , Figure 2 ;

[0048] The outer rotor lamination includes a plurality of outer rotor lamination units 12 arranged circumferentially around the inner rotor lamination 11. Adjacent outer rotor lamination units are independent of each other and form the magnetic slots 13. The outer contour of each outer rotor lamination unit 12 is a continuous arc formed by the intersection of at least two eccentric arcs. The center of each eccentric arc is eccentrically set with respect to the center of the outer circle of the rotor core lamination.

[0049] The design of an eccentric circular arc can be achieved using the following two methods.

[0050] In the first preferred embodiment, see 8, the outer contour of the outer rotor lamination unit 12 can be formed by the intersection of two eccentric circular arcs. The eccentric circular arcs include a first eccentric circular arc P1 and a second eccentric circular arc P2. The center of the first eccentric circular arc P1 is set to O1, the radius of the first eccentric circular arc P1 is set to R1, and the circle containing the first eccentric circular arc P1 is set to C1. The center of the second eccentric circular arc P2 is set to O2, the radius of the second eccentric circular arc P2 is set to R2, and the circle containing the second eccentric circular arc P2 is set to C2. The center of the outer circle C0 of the rotor core lamination is set to O, and the radius of the outer circle C0 of the rotor core lamination is set to R.

[0051] Among them, the center O, center O1 and center O2 are all on the same straight line, that is, the three points of center O, O1 and O2 are all on the same straight line after being connected and are set radially along the outer circle of the rotor core lamination; and the eccentricity of center O1 relative to circle O is L1, the eccentricity of center O2 relative to center O1 is L2, and R2+L1+L2>R.

[0052] The second preferred option is described in [link / reference]. Figure 10 The outer contour of the outer rotor lamination unit 12 can be formed by the intersection of three eccentric circular arcs. The eccentric circular arcs include a third eccentric circular arc, a fourth eccentric circular arc, and a fifth eccentric circular arc. The center of the third eccentric circular arc is set to O3, the radius of the third eccentric circular arc is set to R3, and the circle containing the third eccentric circular arc is set to C3. The center of the fourth eccentric circular arc is set to O4, the radius of the fourth eccentric circular arc is set to R4, and the circle containing the fourth eccentric circular arc is set to C4. The center of the fifth eccentric circular arc is set to O5, the radius of the fifth eccentric circular arc is set to R5, and the circle containing the fifth eccentric circular arc is set to C5. The center of the outer circle of the rotor core lamination is set to O, and the radius of the outer circle of the rotor core lamination is set to R.

[0053] Among them, the fourth eccentric arc and the fifth eccentric arc are a pair of arcs that are symmetrically arranged with respect to the third eccentric arc. Let the eccentricity of the center O3 relative to the circle O be L3, the eccentricity of the center O4 relative to the center O3 be L4, and the eccentricity of the center O5 relative to the center O3 be L5. Then R4+L3+L4>R, R5+L3+L5>R, and R4=R5, L4=L5.

[0054] In this scheme, the line connecting the centers O and O3 is set along the radial direction of the outer circle of the rotor core lamination. However, the line connecting the centers O3 and O4, as well as the line connecting the centers O3 and O5, is deviated from the radial direction of the outer circle of the rotor core lamination. Furthermore, the three points O, O3, and O4, or the three points O, O3, and O5, are not on the same straight line after being connected.

[0055] The difference between the first and second schemes is that in the first scheme, the second arc is drawn from the same center, while in the second scheme, the second arc becomes two arcs of equal length and symmetrical to each other, drawn from different centers, namely the fourth arc and the fifth arc.

[0056] The design of the multi-eccentric circular arc structure can effectively control the air gap magnetic flux density and improve the back electromotive force waveform while ensuring the output characteristics. Experiments show that by reasonably selecting the value of the first segment of the eccentric circular arc, the air gap magnetic flux density amplitude can be reduced by about 7% and the waveform is more sinusoidal under the same output performance.

[0057] The aforementioned second and / or third eccentric arcs can effectively improve the low-order harmonic content and sinusoidal waveform of the air gap magnetic field. Experiments show that, with reasonable selection of the second and / or third eccentric arcs, the air gap magnetic flux density distortion rate can be reduced by about 30% and the waveform becomes more sinusoidal under the same output performance.

[0058] In this embodiment, the inner rotor lamination 11 is circular, and the inner rotor lamination 11 has spaced positioning bosses 112 formed along its outer periphery. The yoke 14 of the rotor assembly is formed between adjacent positioning bosses 112. The positioning bosses 112 are designed to facilitate the installation and positioning of the magnet sheet 2, improve assembly consistency, improve packaging flow, thereby improving packaging quality and further enhancing structural strength.

[0059] Each outer rotor lamination unit 12 is approximately fan-shaped, with a tooth 15 formed at the small end of the fan shape. This tooth 15 corresponds to the yoke 14 of the inner rotor lamination 11. At least one set of corresponding outer rotor lamination units 12 have a partition bridge 16 between their tooth 15 and the yoke 14 of the inner rotor lamination 11. The partition bridge 16 structure fully considers the magnetic field distribution and the direction of magnetic field lines, which can reduce or avoid leakage magnetic field and improve performance.

[0060] Not every tooth 15 and yoke 14 needs to be separated by a partition bridge 16. Where a partition bridge 16 is not provided, the magnetic resistance of the leakage magnetic circuit of the yoke 14 can be increased, thereby reducing leakage magnetic flux and improving performance. Where a partition bridge 16 is provided, the connection strength between the tooth 15 and yoke 14 can be further strengthened to prevent the tooth 15 and yoke 14 from separating, thereby improving assembly accuracy.

[0061] Therefore, considering overall performance and processing cost, there can be m partition bridges 16, where m ranges from X / 2, and X is the number of pole pairs. The partition bridges 16 are arranged along the circumferential direction, spaced at intervals of one outer rotor lamination unit 12. In this embodiment, the number of pole pairs is 10, so the number of partition bridges 16 is 5. All partition bridges 16 are arranged along the circumferential direction, spaced at intervals of one outer rotor lamination unit 12. Each partition bridge 16 passes through the center of the outer circle of the rotor core lamination and is arranged radially. See [reference needed]. Figure 1 The design of the partition bridge 16 with an interval of one outer rotor lamination unit 12 in this embodiment greatly suppresses the leakage flux, increases the effective magnetic flux, and reduces the leakage flux coefficient (total magnetic flux / effective magnetic flux), thereby improving the motor output torque and efficiency. Experiments show that the partition bridge 16 can improve the output torque performance by about 5%.

[0062] In addition, such as Figure 9 As shown, the fan-shaped large end of each outer rotor lamination unit 12 extends to both sides to form a magnet positioning part 121 that narrows from wide to narrow. Taking the extension line of the narrowest part 122 of the magnet positioning part 121 as the reference line L, the height ratios obtained by the two eccentric arcs after intersecting the reference line L relative to the bottom edge 123 of the magnet positioning part 121 are h and H, respectively. Then h ≥ 1 / 2H. Therefore, the larger h is, the smaller the output torque, the smaller the amplitude of each order harmonic of the air gap magnetic flux density, and the lower the distortion rate. Therefore, by reasonably designing the eccentric arc, it is possible to ensure that the output torque meets the requirements and effectively improves the low-order harmonic content and waveform sinusoidal nature of the air gap magnetic field.

[0063] The inner rotor lamination 11 is also provided with first self-locking holes 113 spaced apart along the circumference for connecting adjacent stacked inner rotor laminations 11. The slot direction of the first self-locking holes 113 is along the circumference of the inner rotor lamination 11. The inner rotor lamination 11 adopts a tangential rectangular self-locking structure, and the self-locking direction is consistent with the magnetic circuit, which can reduce the magnetic resistance generated by self-locking.

[0064] Each outer rotor lamination unit 12 has a second self-locking hole 124 for connecting adjacent stacked outer rotor laminations; the groove direction of the second self-locking hole 124 is along the radial direction of the outer rotor lamination. The outer rotor lamination adopts a radial rectangular self-locking structure, which can reduce the radial displacement generated when the lamination assembly enters the shaft at the central through hole, thereby avoiding changes in the size of the magnet slot 13.

[0065] Each outer rotor lamination unit 12 is also provided with an auxiliary circular self-locking 125 for increasing the mechanical strength of the lamination.

[0066] Each outer rotor lamination unit 12 is also provided with circular process holes 126. These process holes 126 can allow for air release during processing and filling, enhancing the density of the filler 3, and at the same time enhancing the mechanical strength of the rotor assembly.

[0067] like Figure 4 , Figure 5 As shown, the cross-section of the magnet sheet 2 in this embodiment is trapezoidal. The length of the upper base of the trapezoidal cross-section of the magnet sheet 2 is set as d1, and the length of the lower base is set as d2, where d1 / d2 = λ, 0 < λ ≤ 1. The larger λ is, the greater the average output torque of the motor, and the greater the cogging torque and pulsating torque. By designing the upper and lower bases of the magnet sheet 2 to be unequal, the cogging torque and pulsating torque can be optimized, thus improving NVH characteristics.

[0068] The basic manufacturing process of this embodiment is as follows:

[0069] Several rotor core laminations are sequentially rotated in the same clockwise (counterclockwise) direction and self-clamped to form a rotor core. The rotation and stacking design improves the rotor dynamic imbalance and reduces the generation of modulation vibration. At the same time, combined with the self-clamping point structure design, the magnetic resistance and displacement during the processing are reduced, which improves the manufacturing precision and consistency in terms of process.

[0070] In the production of rotor assemblies, an integrated injection molding or potting process is used to encapsulate and wrap each rotor core lamination and magnet sheet 2, so that all structural components form a solid and reliable whole, which greatly improves the structural strength of the rotor assembly. At the same time, experiments show that the cost of the motor is reduced by about 8% with this rotor assembly structure.

[0071] After the rotor core is stacked, the magnet sheet 2 is inserted into the magnet slot 13 and forms an air gap with the rotor core. The filler 3 then fills the air gap. The filler 3 is preferably injection molding material or potting material, which can realize the one-piece injection molding or potting molding process. The processing technology is simple and reliable, with strong stability, and can meet the centrifugal stress requirements of the rotor under high speed operation.

[0072] In this embodiment, the outer rotor lamination adopts a multi-eccentric circular arc design, which greatly suppresses the leakage flux and improves the output torque characteristics of the motor. At the same time, it effectively improves the air gap magnetic field and back electromotive force waveform, thus improving both the output torque characteristics and NVH characteristics of the motor.

[0073] In the specification and claims of this utility model, terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," are used to describe various exemplary structural parts and elements of this utility model. However, the use of these terms is merely for the purpose of explanation and is based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this utility model can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0074] In the description of this utility model patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an adhesive connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model patent based on the specific circumstances.

Claims

1. An electric motor rotor, characterized in that, The motor rotor includes: The rotor core assembly (1) includes a plurality of rotor core laminations stacked sequentially. The rotor core laminations include an inner rotor lamination (11) and an outer rotor lamination. The inner rotor laminations (11) are stacked to form an inner rotor core, and the outer rotor laminations are stacked to form an outer rotor core. The inner rotor core is formed with a shaft hole (111), the center of which is the center of the outer circle of the rotor core lamination. The outer rotor core is also provided with magnetic slots (13) at intervals along the circumference. The magnet assembly includes a magnet sheet (2) that can be embedded in the magnet groove (13); and Filler (3) is used to fill the gap formed between the inner rotor core and the outer rotor core; The outer rotor lamination includes multiple outer rotor lamination units (12) arranged circumferentially around the inner rotor lamination (11). Adjacent outer rotor lamination units are independent of each other and form the magnetic slots (13). The outer contour of each outer rotor lamination unit (12) is a continuous arc formed by the intersection of at least two eccentric arcs. The center of each eccentric arc is eccentrically set with respect to the center of the outer circle of the rotor core lamination.

2. The motor rotor according to claim 1, characterized in that: The rotor core assembly (1) includes multiple rotor core laminations that are stacked and formed by rotating n° in sequence, where n° = 360° / 2P and 2P is the number of pole pairs.

3. The motor rotor according to claim 1, characterized in that: The eccentric arc includes a first eccentric arc and a second eccentric arc. The center of the first eccentric arc is set to O1, and the radius of the first eccentric arc is set to R1. The center of the second eccentric arc is set to O2, and the radius of the second eccentric arc is set to R2. The center of the outer circle of the rotor core lamination is set to O, and the radius of the outer circle of the rotor core lamination is set to R. In this case, the center O, center O1, and center O2 are all on the same straight line, and the eccentricity of center O1 relative to circle O is L1, the eccentricity of center O2 relative to center O1 is L2, and R2+L1+L2>R.

4. The motor rotor according to claim 1, characterized in that: The eccentric arc includes a third eccentric arc, a fourth eccentric arc, and a fifth eccentric arc. The center of the third eccentric arc is set to O3, and the radius of the third eccentric arc is set to R3. The center of the fourth eccentric arc is set to O4, and the radius of the fourth eccentric arc is set to R4. The center of the fifth eccentric arc is set to O5, and the radius of the fifth eccentric arc is set to R5. The center of the outer circle of the rotor core lamination is set to O, and the radius of the outer circle of the rotor core lamination is set to R. The fourth and fifth eccentric arcs are symmetrically arranged on both sides of the third eccentric arc. The eccentricity of the center O3 relative to the circle O is L3, the eccentricity of the center O4 relative to the center O3 is L4, and the eccentricity of the center O5 relative to the center O3 is L5. R4+L3+L4>R, R5+L3+L5>R, and R4=R5, L4=L5.

5. The motor rotor according to claim 1, characterized in that: Each of the outer rotor lamination units (12) is fan-shaped. The large end of the fan-shaped lamination unit (12) extends to both sides to form a magnet positioning part (121) that narrows from wide to narrow. Taking the extension line of the narrowest part of the magnet positioning part (121) as the reference line, the height ratio obtained after the two eccentric arcs intersect the reference line are h and H respectively, then h≥1 / 2H.

6. The motor rotor according to claim 1, characterized in that: The inner rotor lamination (11) and the outer rotor lamination are connected by at least one partition bridge (16) along the circumferential direction.

7. The motor rotor according to claim 6, characterized in that: There are m partition bridges (16), where m ranges from X / 2, and X is the number of pole pairs. The partition bridges (16) are set at intervals of one outer rotor lamination unit (12) along the circumferential direction.

8. The motor rotor according to claim 1, characterized in that: The inner rotor lamination (11) is circular, and the inner rotor lamination (11) has spaced positioning bosses (112) formed along its outer periphery, and the yoke (14) of the rotor assembly is formed between adjacent positioning bosses (112).

9. The motor rotor according to claim 8, characterized in that: Each of the outer rotor lamination units (12) is fan-shaped, and the small end of the fan-shaped part of each outer rotor lamination unit (12) forms a tooth (15). The tooth (15) corresponds to the yoke (14) of the inner rotor lamination (11). A partition bridge (16) is provided between the tooth (15) of at least one set of corresponding outer rotor lamination units (12) and the yoke (14) of the inner rotor lamination (11).

10. The motor rotor according to claim 1, characterized in that: The inner rotor lamination (11) is also provided with first self-locking holes (113) spaced apart along the circumference for connecting adjacent stacked inner rotor laminations (11), and the slot direction of the first self-locking holes (113) is along the circumference of the inner rotor lamination (11).

11. The motor rotor according to claim 1, characterized in that: Each of the outer rotor lamination units (12) is provided with a second self-locking hole (124) for connecting adjacent stacked outer rotor laminations; the groove direction of the second self-locking hole (124) is opened along the radial direction of the outer rotor lamination.

12. The motor rotor according to claim 1, characterized in that: Each of the outer rotor lamination units (12) is also provided with an auxiliary circular self-locking mechanism (125) for increasing the mechanical strength of the lamination.

13. The motor rotor according to claim 1, characterized in that: Each of the outer rotor lamination units (12) is also provided with process holes (126) to enable fluid exhaust.

14. The motor rotor according to claim 1, characterized in that: The cross-section of the magnetic steel sheet (2) is trapezoidal. The length of the upper base of the trapezoidal cross-section of the magnetic steel sheet (2) is set as d1, and the length of the lower base of the trapezoidal cross-section of the magnetic steel sheet (2) is set as d2, where d1 / d2=λ, 0<λ≤1.

15. An electric motor comprising a rotor and a stator, characterized in that: The rotor is an electric motor rotor as described in any one of claims 1 to 14.

16. A range hood, comprising a casing, a fan, and an electric motor for driving the fan to rotate, characterized in that: The electric motor is the electric motor as described in claim 15.

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