Motors, compressors and refrigeration equipment

Abstract

This invention relates to an electric motor, a compressor, and a refrigeration device, used to alleviate the problem of mutual constraints between motor efficiency and noise. The electric motor includes a rotor core comprising: at least two first slots configured to accommodate permanent magnets, the at least two first slots being arranged around the central axis of the rotor core; and a second slot located outside at least one of the at least two first slots, the second slot penetrating the rotor core along its axial direction, and extending towards the outer edge of the rotor core; the second slot includes a first portion near the first slot and a second portion away from the first slot, the width of the first portion being greater than the width of the second portion, which can rationally distribute the rotor magnetic circuit, guide the magnetic flux direction, reduce magnetomotive force harmonics generated by the interaction between the stator magnetic flux and the rotor magnetic circuit, reduce electromagnetic noise, reduce torque pulsation, and prevent the attenuation of motor efficiency.

Description

Technical Field

[0001] This invention relates to the field of electric motors, and more particularly to an electric motor, a compressor, and a refrigeration device. Background Technology

[0002] While increasing the amount of permanent magnets in a permanent magnet synchronous motor can improve efficiency, it exacerbates cogging effect and local magnetic field distortion, leading to increased electromagnetic noise during operation. Methods to reduce noise include increasing the air gap between the stator and rotor and reducing the thickness of the permanent magnets, but these reduce the magnetic flux density in the air gap, affecting motor efficiency. Therefore, motor efficiency and electromagnetic noise are somewhat mutually restrictive. Summary of the Invention

[0003] Some embodiments of the present invention provide a motor, compressor, and refrigeration equipment to alleviate the problem of mutual constraints between motor efficiency and noise.

[0004] Some embodiments of the present invention provide an electric motor comprising a rotor core, the rotor core comprising:

[0005] At least two first slots are configured to accommodate permanent magnets, the at least two first slots being arranged around the central axis of the rotor core; and

[0006] The second slot is located outside at least one of the at least two first slots. The second slot extends through the rotor core along the axial direction of the rotor core and also extends towards the outer edge of the rotor core. The second slot includes a first portion close to the first slot and a second portion away from the first slot, wherein the width of the first portion is greater than the width of the second portion.

[0007] In some embodiments, the first slot is configured as a symmetrical structure, the line of symmetry of the first slot is located on a radial line of the rotor core, and at least one second slot is provided on each side of the line of symmetry.

[0008] In some embodiments, the first portion includes a first end and a second end along its width direction, the second end being close to the line of symmetry relative to the first end, the second portion connecting to the second end of the first portion and extending toward the outer edge of the rotor core.

[0009] In some embodiments, the side of the first part and the second part closest to the line of symmetry is parallel to the line of symmetry.

[0010] In some embodiments, the width of the first part is W 11 The width of the second part is W 12 2W 12 ≤W 11 ≤2.8W12 .

[0011] In some embodiments, the width W1 of the second groove is W 11 And W1 < H1, H1 = H 11 +H 12 , where H 11 H is the height of the first part. 12 This refers to the height of the second part.

[0012] In some embodiments, H 11 ≥H 12 .

[0013] In some embodiments, the second groove further includes a third portion located between the third portion and the first portion, the third portion extending toward the line of symmetry.

[0014] In some embodiments, the width of the first part is W 21 The width of the second part is W 22 The width of the third part is W 23 2W 22 ≤W 21 ≤W 22 +W 23 .

[0015] In some embodiments, the width W2 of the second groove is W 21 +W 23 And W2 < H2, H2 = H 21 +H 22 , where H 21 H is the height of the first part. 22 It is the sum of the height of the second part and the height of the third part.

[0016] In some embodiments, H 21 ≥H 22 .

[0017] In some embodiments, a second groove is provided on each side of the symmetry line, and one second groove on one side of the symmetry line is symmetrical to one second groove on the other side of the symmetry line; or, two second grooves are provided on each side of the symmetry line, and two second grooves on one side of the symmetry line are symmetrical to two second grooves on the other side of the symmetry line.

[0018] In some embodiments, the two second grooves on the same side of the line of symmetry may have the same or different structures.

[0019] In some embodiments, at least two second slots are provided on each side of the symmetry line, and a magnetic channel is formed between each pair of adjacent second slots on the same side of the symmetry line. At least one magnetic channel is provided with a first recess on the outer edge of the rotor core.

[0020] In some embodiments, the motor further includes a stator core configured as an annular shape, a rotor core passing through the stator core, a gap of g between the rotor core and the stator core, and a first recess recessed to a depth of D, where D ≤ g / 3.

[0021] In some embodiments, the motor further includes a stator core configured as an annular shape, a rotor core passing through the stator core, a gap of g between the rotor core and the stator core, a height of W3 in the first slot, and a minimum width of W4 for the magnetic channel, where g < W4 < W3.

[0022] In some embodiments, in the second slot located on one side of the symmetry line, the outer edge of the rotor core corresponding to the end of the second slot furthest from the symmetry line and the end of the first slot adjacent to it is provided with a second recess.

[0023] In some embodiments, the second recess includes a first wall and a second wall, the first groove includes a first groove portion located on one side of the line of symmetry and a second groove portion located on the other side of the line of symmetry, the first wall is parallel to the side of the first groove portion or the second groove portion adjacent to it, and the second wall has a preset included angle α between it and the first wall.

[0024] In some embodiments, the included angle between the first groove and the second groove is β, wherein 0.5β≤α≤β.

[0025] In some embodiments, the distance between the first wall and its parallel side is S, the motor further includes a stator core configured as an annular shape, the rotor core passing through the stator core, and the gap between the rotor core and the stator core is g, where 0.8g≤S≤11.5g.

[0026] In some embodiments, the motor further includes a stator core configured as an annular structure, wherein the inner wall of the stator core is provided with a plurality of third grooves recessed toward the outer edge of the stator core at intervals, the third grooves being configured to accommodate windings of the stator core, and a tooth being formed between adjacent third grooves, the tooth including a first tooth portion, a second tooth portion and a third tooth portion, the first tooth portion being away from the central axis of the stator core relative to the second tooth portion, the third tooth portion being configured as a trapezoid, the short side of the third tooth portion being connected to the first tooth portion, the long side of the third tooth portion being connected to the second tooth portion, and the distances from the two ends of the inclined side of the third tooth portion to the side of the second tooth portion near the rotor core being S1 and S2, respectively, where 2.2≤S2 / S1≤2.6.

[0027] Some embodiments of the present invention provide a compressor that includes the motor described above.

[0028] Some embodiments of the present invention provide a refrigeration device that includes the compressor described above.

[0029] Based on the above technical solution, the present invention has at least the following beneficial effects:

[0030] In some embodiments, a first slot for accommodating a permanent magnet is provided on the rotor core, and a second slot is provided outside the first slot. The first part of the second slot is close to the permanent magnet, and the second part of the second slot is close to the outer edge of the rotor core. The width of the first part is greater than the width of the second part, which can reasonably distribute the rotor magnetic circuit, guide the direction of the magnetic flux, reduce the magnetomotive force harmonics generated by the interaction between the stator magnetic flux and the rotor magnetic circuit, reduce electromagnetic noise, reduce torque pulsation, and avoid the attenuation of motor efficiency. Attached Figure Description

[0031] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0032] Figure 1 A schematic diagram of a rotor core provided according to some embodiments of the present invention;

[0033] Figure 2 for Figure 1 A magnified schematic diagram of a local structure;

[0034] Figure 3 A schematic diagram of a second groove provided according to some embodiments of the present invention;

[0035] Figure 4 A schematic diagram of a second groove provided according to other embodiments of the present invention;

[0036] Figure 5This is a schematic diagram of the cooperation between the rotor core and the stator core according to the first embodiment of the present invention;

[0037] Figure 6 for Figure 5 A magnified schematic diagram of a local structure;

[0038] Figure 7 This is an enlarged schematic diagram of a partial structure of a stator core according to some embodiments of the present invention;

[0039] Figure 8 This is a schematic diagram of the cooperation between the rotor core and the stator core according to the second embodiment of the present invention;

[0040] Figure 9 This is a schematic diagram of the cooperation between the rotor core and the stator core according to the third embodiment of the present invention. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention 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. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0043] The electric motor includes a rotor and a stator. The rotor includes a rotor core with a first slot containing a permanent magnet. The stator includes a stator core with a third slot containing a winding. The permanent magnet in the first slot provides rotor flux linkage, and the winding in the third slot provides stator flux linkage. The interaction between the stator flux linkage and the rotor magnetic circuit generates torque. The tangential torque along the rotor rotation direction drives the motor, while the torque along the rotor radial direction generates electromagnetic force, but also produces electromagnetic noise.

[0044] To improve motor efficiency, one approach is to increase the amount of permanent magnets used, thereby increasing the electromagnetic harmonic content in the radial direction. However, this also increases electromagnetic noise.

[0045] Based on this, some embodiments of this disclosure provide a motor for mitigating the problems of electromagnetic noise and torque pulsation caused by efforts to improve motor efficiency.

[0046] refer to Figure 1 The motor includes a rotor core 1, which includes at least two first slots 11 and second slots 12.

[0047] At least two first slots 11 are configured to accommodate permanent magnets, and each of the at least two first slots 11 is arranged around the central axis of the rotor core 1. The length direction of each first slot 11 is consistent with the axial direction of the rotor core 1, and each first slot 11 penetrates the rotor core 1 along the axial direction of the rotor core 1.

[0048] The second slot 12 is located outside at least one of the at least two first slots 11. Here, "outer side" refers to the side away from the central axis of the rotor core 1, or the side close to the outer edge of the rotor core 1. The second slot 12 extends through the rotor core 1 along its axial direction. The length of the second slot 12 extends in the same direction as the axial direction of the rotor core 1. The second slot 12 also extends towards the outer edge of the rotor core 1. The direction of extension of the second slot 12 towards the outer edge of the rotor core 1 is the height direction of the second slot 12. The second slot 12 includes a first portion 121 close to the first slot 11 and a second portion 122 away from the first slot 11. That is, the first portion 121 is closer to the first slot 11 than the second portion 122, and the second portion 122 is closer to the outer edge of the rotor core 1 than the first portion 121. The width of the first portion 121 is greater than the width of the second portion 122. Here, "width" in the widths of the first portion 121 and the second portion 122 refers to the dimension perpendicular to the length and height directions of the second slot 12, i.e., reference... Figures 2 to 4 The dimension in the direction perpendicular to the line of symmetry 113.

[0049] The second groove 12 is located outside the first groove 11. The specific location is not limited. For example, the second groove 12 can be located near the end of the first groove 11 or in the middle area of ​​the first groove 11. The spatial layout is wide.

[0050] A second slot 12 is provided outside the first slot 11. The magnetic fields of the stator and rotor can avoid flowing through the second slot 12 in the magnetic circuit of the rotor core 1. Therefore, the second slot 12 has a magnetic shielding effect, which can reduce magnetic leakage, increase output torque, and reduce torque pulsation. Furthermore, the setting position and structural shape of the second slot 12 can limit the magnetic circuit size and change the direction of the rotor magnetic circuit, which can reduce the content of magnetic flux harmonics and greatly reduce electromagnetic noise.

[0051] Furthermore, the width of the first part 121 of the second slot 12 is greater than the width of the second part 122. That is to say, the width of the part of the second slot 12 near the permanent magnet is large, and the width of the part near the outer edge of the rotor core 1 is small. This can reasonably distribute the rotor magnetic circuit, guide the direction of the magnetic flux, reduce the magnetomotive force harmonics generated by the interaction between the stator magnetic flux and the rotor magnetic circuit, reduce electromagnetic noise, reduce torque pulsation, and at the same time maintain the motor efficiency without decay.

[0052] In some embodiments, the first slot 11 is configured as a symmetrical structure, the symmetry line 113 of the first slot 11 is located on a radial line of the rotor core 1, and at least one second slot 12 is provided on both sides of the symmetry line 113.

[0053] The first slot 11 is constructed as a symmetrical structure, for example: [reference needed] Figure 8 The first groove 11 shown has a V-shaped cross-section, or, refer to Figure 9 The first groove 11 shown has a cross-section that is elongated.

[0054] At least one second groove 12 is provided on each side of the symmetry line 113 of the first groove 11, for example: (Refer to...) Figure 8 As shown, a second groove 12 is provided on each side of the symmetry line 113 of the first groove 11, or, refer to Figure 5 As shown in Figure 9, two second grooves 12 are respectively provided on both sides of the symmetry line 113 of the first groove 11, or three or more second grooves 12 are respectively provided on both sides of the symmetry line 113 of the first groove 11.

[0055] The structures of the second grooves 12 located on the same side of the symmetry line 113 of the first groove 11 are the same or different, and the structures of the second grooves 12 located on different sides of the symmetry line 113 of the first groove 11 are the same or different.

[0056] In some embodiments, the first portion 121 of the second groove 12 includes a first end and a second end along its width direction, where "width direction" refers to a direction perpendicular to the line of symmetry 113, as shown in the reference. Figures 2 to 4 The second end of the second slot 12 is close to the line of symmetry 113 relative to the first end. The second part 122 of the second slot 12 is connected to the second end of the first part 121 and extends to the outer edge of the rotor core 1.

[0057] The first part 121 of the second groove 12 is connected to the second part 122, forming an L-shaped structure. That is, the second groove 12 located on one side of the symmetry line 113 of the first groove 11 can be a forward L-shaped structure, and the second groove 12 located on the other side of the symmetry line 113 of the first groove 11 can be a reverse L-shaped structure. (See reference...) Figure 2The second groove 12, with an "L"-shaped structure on both sides of the symmetry line 113 of the first groove 11, is symmetrically arranged about the symmetry line 113.

[0058] In some embodiments, the second part 122 and the first part 121 of the second groove 12 are parallel to the symmetry line 113 on the side closest to the symmetry line 113.

[0059] The second slot 12 has a portion that is parallel to the symmetry line 113 of the first slot 11, so that the magnetic channel 15 that guides the magnetic field is parallel to the symmetry line 113 of the first slot 11. The non-parallel nature of the magnetic channel 15 and the symmetry line 113 can shorten the rotor magnetic field flow path and reduce noise.

[0060] The second slot 12 has a second part 122 extending along the symmetry line 13 of the first slot 11, and a first part 121 extending perpendicular to the symmetry line 113 of the first slot 11; the stator and rotor magnetic flux can be concentrated on both sides of the "L"-shaped second slot 12, which has the function of guiding the flow of magnetic flux and improving the magnetic potential harmonics.

[0061] refer to Figure 3 In some embodiments, the width of the first part 121 of the second groove 12 is W. 11 The width of the second part 122 of the second groove 12 is W. 12 2W 12 ≤W 11 ≤2.8W 12 .

[0062] The width W of the first part 121 of the second slot 12 11 The width W of the second part 122 is greater than that of the second groove 12. 12 It can improve the magnetic flux flow path, reduce noise, reduce the impact of output torque, and alleviate the problem of mutual constraint between motor efficiency and noise.

[0063] In some embodiments, the width W1 of the second groove 12 is W 11 And W1 < H1, H1 = H 11 +H 12 , where H 11 H is the height of the first part 121 of the second slot 12. 12 This refers to the height of the second part 122 of the second slot 12. The "height" in the context of the heights of the first part 121 and the second part 122 refers to the dimension along the line of symmetry 113 of the first slot 11, as shown in the reference section. Figure 2 .

[0064] The second slot 12 extends along the symmetry line 113 of the first slot 11 and is slit-shaped, satisfying W1 < H1, so that the height of the second slot 12 is greater than its width, thus avoiding the second slot 12 being too wide and obstructing the flow of the rotor magnetic field too much.

[0065] In some embodiments, H 11 ≥H 12 .

[0066] Along the extension direction of the symmetry line 113 of the first slot 11, the height of the first part 121 of the second slot 12 is not less than the height of the second part 122. That is, the height of the wider first part 121 near the first slot 11 is large, and the height of the narrower second part 122 near the outer edge of the rotor core 11 is small. In the magnetic field guided by this structure, the path through the wider first part 121 is longer than the path through the narrower second part 122, which has the effect of improving magnetomotive force harmonics, and simultaneously reducing electromagnetic noise and improving torque output capability.

[0067] In some embodiments, the second groove 12 further includes a third part 123, the second part 122 is located between the third part 123 and the first part 121, the third part 123 connects the end of the second part 122 away from the first part 121, and the third part 123 extends toward the line of symmetry 113.

[0068] The first part 121, the second part 122, and the third part 123 of the second groove 12 form a Z-shaped structure. The second groove 12 on one side of the line of symmetry 113 of the first groove 11 is Z-shaped, while the second groove 12 on the other side of the line of symmetry 113 of the first groove 11 is a reverse Z-shaped structure. (Reference) Figure 2 The second groove 12, which is shaped like a "Z" on one side of the symmetry line 113 of the first groove 11, is symmetrical about the symmetry line 113 to the second groove 12, which is shaped like a "Z" on the other side of the symmetry line 113.

[0069] Compared to the second slot 12 of the "L"-shaped structure, the second slot 12 of the "Z"-shaped structure has an increased width near the outer edge of the rotor core 11, which can further improve the magnetic shielding effect and reduce torque pulsation.

[0070] In some embodiments, the second slot 12 has a second portion 122 extending along the symmetry line 113 of the first slot 11, a first portion 121 extending perpendicular to the symmetry line 113 of the first slot 11, and a third portion 123 parallel to the outer edge of the rotor core 1.

[0071] refer to Figure 4 In some embodiments, the width of the first part 121 of the second groove 12 is W. 21 The width of the second part 122 of the second groove 12 is W. 22 The width of the third part 123 of the second groove 12 is W. 23 2W 22 ≤W 21 ≤W 22 +W 23This reduces torque pulsation, lowers the content of motor magnetomotive force harmonics, and has a better overall effect.

[0072] In some embodiments, the width W2 of the second groove 12 is W 21 +W 23 And W2 < H2, H2 = H 21 +H 22 , where H 21 H is the height of the first part 121 of the second slot 12. 22 It is the sum of the height of the second part 122 of the second groove 12 and the height of the third part 123 of the second groove 12.

[0073] The width W2 of the second groove 12 is less than the sum of the heights of the first part 121, the second part 122 and the third part 123 of the second groove 12. The second groove 12 is generally in the shape of a thin strip or a slit, so as to avoid the second groove 12 being too wide and thus hindering the flow of the rotor magnetic field, resulting in a reduction in torque.

[0074] In some embodiments, H 21 ≥H 22 .

[0075] Along the symmetry line 113 of the first slot 11, the height of the first part 121 of the second slot 12 is not less than the sum of the heights of the second part 122 and the third part 123. That is, the height of the wider first part 121 near the first slot 11 is large, and the sum of the heights of the narrower second part 122 and the third part 123 near the outer edge of the rotor core 1 is small. In the magnetic field guided by this structure, the path of the wider part is longer than the path of the narrower part, which can reasonably distribute the influence of the second slot 12, and take into account both reducing electromagnetic noise and improving torque output capability.

[0076] Since the stator and rotor magnetic fields bypass the second slot 12 during the flow process and flow on the magnetic circuit of the rotor core 1, the magnetic circuit size can be limited by limiting the width and height of each part of the second slot 12, thereby reducing the content of magnetic flux harmonics and greatly reducing electromagnetic noise.

[0077] In some embodiments, a second groove 12 is provided on each side of the symmetry line 113, and a second groove 12 on one side of the symmetry line 113 is symmetrical to a second groove 12 on the other side of the symmetry line 113.

[0078] For example, an "L"-shaped second groove 12 is provided on each side of the symmetry line 113, and the "L"-shaped second grooves 12 provided on both sides of the symmetry line 113 are symmetrical.

[0079] Alternatively, a second "Z"-shaped groove 12 is provided on each side of the symmetry line 113, and the second "Z"-shaped grooves 12 provided on each side of the symmetry line 113 are symmetrical.

[0080] In some embodiments, two second grooves 12 are provided on each side of the symmetry line 113, and the two second grooves 12 on one side of the symmetry line 113 are symmetrical to the two second grooves 12 on the other side of the symmetry line 113.

[0081] For example, two "L"-shaped second grooves 12 are provided on each side of the symmetry line 113, and the two "L"-shaped second grooves 12 provided on one side of the symmetry line 113 are symmetrical to the two "L"-shaped second grooves 12 provided on the other side of the symmetry line 113.

[0082] Alternatively, two "Z"-shaped second grooves 12 are provided on both sides of the symmetry line 113, and the two "Z"-shaped second grooves 12 provided on one side of the symmetry line 113 are symmetrical to the two "Z"-shaped second grooves 12 provided on the other side of the symmetry line 113.

[0083] Alternatively, an "L"-shaped second slot 12 and a "Z"-shaped second slot 12 are provided on each side of the symmetry line 113. The "L"-shaped second slot 12 and the "Z"-shaped second slot 12 on one side of the symmetry line 113 are symmetrical to the "L"-shaped second slot 12 and the "Z"-shaped second slot 12 on the other side of the symmetry line 113. Located on the same side of the symmetry line 113, the "L"-shaped second slot 12 is closer to the symmetry line 113 than the "Z"-shaped second slot 12. The cooperation of the "L"-shaped second slot 12 and the "Z"-shaped second slot 12 can simultaneously improve the output torque efficiency and reduce torque ripple and electromagnetic noise.

[0084] In some embodiments, the two second grooves 12 on one side of the symmetry line 113 may have the same or different structures.

[0085] In some embodiments, by opening second slots 12 of different shapes and symmetrically distributed on the rotor core 1 outside the first slot 11, the stator magnetic flux flows through the rotor core 1, which can reasonably distribute the rotor magnetic circuit, reduce the magnetomotive force harmonics generated by the interaction between the stator magnetic flux and the rotor magnetic circuit, and reduce electromagnetic noise.

[0086] Since the second slot 12 provided on the rotor core 1 will increase the torque pulsation of the motor, in order to reduce the torque pulsation and improve the 0th order noise problem caused by the cogging effect, a recess is provided on the edge of the rotor core 1.

[0087] In some embodiments, at least two second slots 12 are provided on both sides of the symmetry line 113, and a magnetic channel 15 is formed between each pair of adjacent second slots 12 on the same side of the symmetry line 113. At least one magnetic channel 15 is provided with a first recess 13 on the outer edge of the rotor core 1.

[0088] Because the stator and rotor magnetic flux is confined by the second slot 12, there is a certain convergence and divergence. Along the symmetry line (permanent magnet center line) of the first slot 11, a magnetic channel 15 is formed between two adjacent second slots 12. The direction of the magnetic channel 15 changes to alter the rotor magnetic circuit. The first recess 13 is located on the magnetic channel 15, distributing the magnetic flux passing through the magnetic channel 15 to both sides of the first recess 13. This is mainly used to reduce the 0th order 18th harmonic electromagnetic force, i.e., to reduce electromagnetic noise.

[0089] refer to Figure 5 In some embodiments, the motor further includes a stator core 2 configured as an annular shape, with a rotor core 1 passing through the stator core 2. The gap between the rotor core 1 and the stator core 2 is g. (Refer to...) Figure 6 The depth of the first recess 13 is D, as referenced. Figure 2 , D≤g / 3.

[0090] Without the first recess 13, the gap between the rotor core 1 and the stator core 2 is g. With the first recess 13, the gap between the rotor core 1 and the stator core 2 increases. The first recess 13 is used to reduce the 0th order 18f electromagnetic force, which is mainly caused by the cogging effect of the stator and rotor. The first recess 13 can alleviate this effect, but it should not have a significant impact on other factors such as output torque. Therefore, the depth of the first recess 13 needs to be limited. Thus, the depth D of the first recess 13 is limited to D≤g / 3.

[0091] refer to Figure 2 The first recess 13 includes two straight sidewalls and an arc-shaped groove bottom. The two straight sidewalls of the first recess 13 are parallel to the line of symmetry 113 of the first groove 11. The arc-shaped groove bottom of the first recess 13 is concentric with the outer edge of the rotor core 1. D1 is the distance between the arc-shaped groove bottom of the first recess 13 and the outer edge of the rotor core 1. Electromagnetic noise is reduced by setting the first recess 13.

[0092] In some embodiments, the motor further includes a stator core 2 configured as an annular structure, a rotor core 1 passing through the stator core 2, a gap of g between the rotor core 1 and the stator core 2, a height of W3 in the first slot 11, and a minimum width of W4 in the magnetic channel 15, where g < W4 < W3.

[0093] A magnetic channel 15 is formed between two adjacent second slots 12. The width of the magnetic channel 15, that is, the distance between two adjacent second slots 12, needs to be limited. If the distance is too short, the magnetic field saturation will be obvious, which is not conducive to the efficiency of the motor. If the distance is too large, the rotor flow space will be wasted, and the space that could have been opened to create a larger second slot 12 will be wasted, and the improvement effect will not be obvious. Therefore, g < W4 < W3 can reduce the magnetic flux density harmonics on the stator and rotor iron cores, effectively reduce electromagnetic force harmonics, and achieve the purpose of reducing noise.

[0094] In some embodiments, in the second slot 12 located on one side of the symmetry line 113, a second recess 14 is provided on the outer edge of the rotor core 1 corresponding to the end of the second slot 12 furthest from the symmetry line 113 and the end of the adjacent first slot 11. By providing the second recess 14, the gap between the stator and the rotor is increased, the magnetic field is weakened, and the source of torque pulsation and electromagnetic noise is reduced. Therefore, noise and torque pulsation can be reduced.

[0095] In some embodiments, a first recess 13 is provided on the outer edge of the rotor core 1 corresponding to the magnetic channel 15, and a second recess 14 is provided on the outer edge of the rotor core 1 corresponding to the end of the first slot 11 and the nearest second slot 12. That is, the first recess 13 is closer to the line of symmetry 113 of the first slot 11, and the second recess 14 is farther away from the line of symmetry 113 of the first slot 11. The first recess 13 and the second recess 14 have different shapes and are distributed at intervals on the outer edge of the rotor core 1, so that the gap between the stator core 2 and the rotor core 1 increases at the first recess 13 and the second recess 14, but does not increase continuously over a large range. This can improve the cogging effect of the motor, reduce the harmonics of the air gap magnetic flux density between the stator and rotor, and thus reduce torque pulsation and electromagnetic noise.

[0096] In some embodiments, the second recess 14 includes a first wall surface 141 and a second wall surface 142, and the first groove 11 includes a first groove portion 111 located on one side of the symmetry line 113 and a second groove portion 112 located on the other side of the symmetry line 113. The first wall surface 141 is parallel to the side of the adjacent first groove portion 111 or second groove portion 112, the angle between the second wall surface 142 and the first wall surface 141 is α, and the angle between the first groove portion 111 and the second groove portion 112 is β, wherein 0.5β≤α≤β. (Refer to...) Figure 6 .

[0097] The smaller the angle α between the second wall 142 and the first wall 141, the greater the torque pulsation; the larger the angle α, the greater the torque attenuation. Limiting the angle α to 0.5β≤α≤β alleviates the problem of mutual constraint between reducing torque pulsation and improving motor efficiency.

[0098] In some embodiments, the distance between the first wall surface 141 and the side of the first groove 111 or the second groove 112 parallel to it is S, referring to... Figure 2 The motor also includes a stator core 2 constructed as an annular ring, with a rotor core 1 passing through the stator core 2. The gap between the rotor core 1 and the stator core 2 is g. (Refer to...) Figure 6 , 0.8g≤S≤11.5g.

[0099] The distance S between the first wall 141 and the side of the first slot 111 or the second slot 112 parallel to it is the main channel for permanent magnet leakage, which determines the leakage and torque ripple improvement. If S is too large, it will not reduce torque ripple. If S is too small, there will be less leakage, but the saturation magnetic flux density here will increase the magnetomotive force harmonic content and affect noise. Therefore, S is related to the gap g that affects the magnetic flux density, so that 0.8g≤S≤11.5g, in order to reduce the leakage and torque ripple of the rotor flux linkage and improve the motor efficiency.

[0100] In some embodiments, reference Figure 5 The motor also includes a stator core 2 constructed as an annular ring. The inner wall of the stator core 2 is provided with a plurality of third grooves 21 recessed toward the outer edge of the stator core 2 at intervals. The third grooves 21 are configured to accommodate stator windings, and teeth 22 are formed between two adjacent third grooves 21.

[0101] refer to Figure 7 The tooth 22 includes a first tooth portion 221, a second tooth portion 222, and a third tooth portion 223. The first tooth portion 221 is away from the central axis of the stator core 2 relative to the second tooth portion 222. The third tooth portion 223 is constructed as a trapezoid. The short side of the third tooth portion 223 is connected to the first tooth portion 221, and the long side of the third tooth portion 223 is connected to the second tooth portion 222. The distances from the two ends of the inclined side of the third tooth portion 223 to the side of the second tooth portion 222 near the rotor core 1 are S1 and S2, respectively, where 2.2≤S2 / S1≤2.6.

[0102] The first tooth 221 of tooth 22 is the tooth body, and the second tooth 222 and the third tooth 223 are tooth shoes. Since electromagnetic vibration of the motor generates electromagnetic noise on the stator teeth, a reasonable tooth structure can effectively increase the stiffness of the motor and improve the magnetic field of the runoff stator. The larger the value of S2 / S1, the smaller S1 is, the smaller the stiffness between the shoes, and the easier it is to vibrate. The smaller the value of S2 / S1, the smaller S2 is, and the more severe the change in magnetic field of the runoff shoe is at this point, which affects the noise. Limiting S2 / S1 to 2.2≤S2 / S1≤2.6 can effectively improve the cogging effect of the stator core tooth shoe on the rotor core and further reduce electromagnetic noise.

[0103] In some embodiments, reference Figure 7 The third tooth 223, near the rotor core 1, includes two straight sides and one arc-shaped side. The two straight sides are perpendicular to the symmetry line 113 of the first slot 11 to increase the vertical clearance between the stator and rotor, alleviate the cogging effect, and reduce torque pulsation. The length of the straight sides of the third tooth 223 is S3, satisfying S4≤S3≤2S4, where S4 is the length of the first wall 141 of the second recess 14 on the rotor core 1. Figure 2 .

[0104] The following are three examples of motor implementations.

[0105] like Figure 5 As shown, this is a first embodiment of the motor. In this first embodiment, the motor includes a rotor core 1 and a stator core 2. The stator core 2 surrounds the rotor core 1, and there is a preset distance between them. The inner circumference of the stator core 2 is provided with a plurality of teeth 22, and a tooth groove 21 is formed between two adjacent teeth 22. The stator winding is arranged in the tooth groove 21.

[0106] Six first slots 11 are evenly spaced around the central axis of the rotor core 1, and a permanent magnet is installed in each first slot 11. Each first slot 11 has a "V"-shaped symmetrical structure, and the line of symmetry 113 of the first slot 11 is located on a radial line of the rotor core 113. Four second slots 12 for noise reduction are provided on the outer side of each first slot 11, with two second slots 12 located on one side of the line of symmetry 113 of the first slot 11, and the other two second slots 12 located on the other side of the line of symmetry 113 of the first slot 11. The two second slots 12 on one side of the line of symmetry 113 of the first slot 11 are symmetrical to the two second slots 12 on the other side of the line of symmetry 113 of the first slot 11.

[0107] like Figure 2 As shown, the two second grooves 12 on one side of the symmetry line 113 of the first groove 11 include a first type of second groove 12a and a second type of second groove 12b. The first type of second groove 12a has an "L" shaped structure, and the second type of second groove 12b has a "Z" shaped structure. The first type of first groove 12a is closer to the symmetry line 113 of the first groove 11 relative to the second type of second groove 12b.

[0108] like Figure 3 As shown, the first type of second groove 12a includes a first part 121 close to the first groove 11 and a second part 122 away from the first groove 11, wherein the width of the first part 121 is greater than the width of the second part 122.

[0109] like Figure 4 As shown, the second type of second groove 12b includes a first part 121, a second part 122 and a third part 123. The first part 121 is close to the first groove 11, and the second part 122 connects the first part 121 and the third part 123. The width of the first part 121 is greater than the width of the second part 122.

[0110] like Figure 2As shown, a magnetic channel 15 is formed between the first type of second slot 12a and the second type of second slot 12b. A first recess 13 is provided on the outer edge of the rotor core 1 corresponding to the magnetic channel 15, and a second recess 14 is provided on the outer edge of the rotor core 1 corresponding to the end of the second type of second slot 12b and the first slot 11. That is, each first slot 11 has a first type of second slot 12a, a second type of second slot 12b, a first recess 13, and a second recess 14 on one side of the symmetry line 113. The first recess 13 is closer to the symmetry line 113 of the first slot 11, and the second recess 14 is farther away from the symmetry line 113 of the first slot 11. The first recess 13 located on one side of the symmetry line 113 of the first slot 11 is symmetrical to the first recess 13 located on the other side of the symmetry line 113 of the first slot 11. The second recess 14 located on one side of the symmetry line 113 of the first slot 11 is symmetrical to the second recess 14 located on the other side of the symmetry line 113 of the first slot 11.

[0111] Multiple second slots 12 of various shapes are set on the rotor magnetic circuit, which can change the shape of the rotor magnetic circuit, improve the harmonic content caused by the interaction of the stator and rotor magnetic fields, and reduce electromagnetic noise and torque pulsation. At the same time, multiple recesses are set on the outer side of the rotor, which can effectively reduce the cogging effect between the stator and rotor and alleviate the noise and torque pulsation problems caused by the inherent electromagnetic force.

[0112] like Figure 8 The diagram shows a second embodiment of the motor. The difference between the second and first embodiments is at least as follows: each first slot 11 has two second slots 12 for noise reduction on its outer side. One second slot 12 is located on one side of the symmetry line 113 of the first slot 11, and the other second slot 12 is located on the other side of the symmetry line 113. The second slot 12 on one side of the symmetry line 113 of the first slot 11 is symmetrical to the second slot 12 on the other side of the symmetry line 113. The second slot 12 is a second type of second slot 12b, which is "Z"-shaped. A second recess 14 is provided on the outer edge of the rotor core 1, but no first recess 13 is provided.

[0113] like Figure 9 As shown, this is the third embodiment of the motor. The difference between the third embodiment and the first embodiment is at least that each first slot 11 is a symmetrical structure of type "I".

[0114] Some embodiments provide a compressor that includes the motor described above.

[0115] Some embodiments provide a refrigeration device that includes the compressor described above. The refrigeration device includes air conditioners, etc.

[0116] In the description of this invention, it should be understood that the use of terms such as "first," "second," and "third" to define components is merely for the purpose of distinguishing the aforementioned components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0117] Furthermore, in the absence of explicit denial, the technical features of one embodiment can be advantageously combined with one or more other embodiments.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. An electric motor, characterized in that, Includes a rotor core (1), said rotor core (1) comprising: At least two first slots (11) are configured to accommodate permanent magnets, the at least two first slots (11) being arranged around the central axis of the rotor core (1); and A second groove (12) is provided on the outside of at least one of the at least two first grooves (11), the second groove (12) penetrates the rotor core (1) along the axial direction of the rotor core (1), and the second groove (12) also extends to the outer edge of the rotor core (1); the second groove (12) includes a first part (121) near the first groove (11) and a second part (122) away from the first groove (11), the width of the first part (121) is greater than the width of the second part (122); The first slot (11) is constructed as a symmetrical structure, and the symmetry line (113) of the first slot (11) is located on a radial line of the rotor core (1); at least two second slots (12) are provided on each side of the symmetry line (113), and a magnetic channel (15) is formed between each pair of adjacent second slots (12) on the same side of the symmetry line (113), and a first recess (13) is provided on the outer edge of the rotor core (1) corresponding to at least one magnetic channel (15).

2. The motor as described in claim 1, characterized in that, The first part (121) includes a first end and a second end along its width direction, the second end being close to the line of symmetry (113) relative to the first end, and the second part (122) connecting to the second end of the first part (121) and extending toward the outer edge of the rotor core (1).

3. The motor as described in claim 2, characterized in that, The first part (121) and the second part (122) are parallel to the symmetry line (113) on the side closest to the symmetry line (113).

4. The motor as described in claim 2, characterized in that, The width of the first part (121) is W 11 The width of the second part (122) is W. 12 2W 12 ≤W 11 ≤2.8W 12 .

5. The motor as described in claim 4, characterized in that, The width W1 of the second groove (12) is W 11 And W1 11 +H 12 , where H 11 H is the height of the first part (121). 12 The height of the second part (122).​ 6. The motor as described in claim 5, characterized in that, H 11 ≥H 12 。 7. The motor as described in claim 2, characterized in that, The second groove (12) also includes a third part (123), which is located between the third part (123) and the first part (121), and the third part (123) extends toward the line of symmetry (113).

8. The motor as described in claim 7, characterized in that, The width of the first part (121) is W 21 The width of the second part (122) is W. 22 The width of the third part (123) is W. 23 2W 22 ≤W 21 ≤W 22 +W 23 .

9. The motor as described in claim 8, characterized in that, The width W2 of the second groove (12) is W2 = W 21 + W 23 , and W2 < H2, where H2 = H 21 + H 22 , where H 21 is the height of the first part (121), and H 22 is the sum of the height of the second part (122) and the height of the third part (123).

10. The motor as described in claim 8, characterized in that, H 21 ≥H 22 。 11. The motor as described in claim 1, characterized in that, A second groove (12) is provided on each side of the symmetry line (113), and one second groove (12) on one side of the symmetry line (113) is symmetrical to one second groove (12) on the other side of the symmetry line (113); or, two second grooves (12) are provided on each side of the symmetry line (113), and two second grooves (12) on one side of the symmetry line (113) are symmetrical to two second grooves (12) on the other side of the symmetry line (113).

12. The motor as described in claim 11, characterized in that, The two second grooves (12) on the same side of the symmetry line (113) may have the same or different structures.

13. The motor as described in claim 1, characterized in that, It also includes a stator core (2) constructed as an annular ring, the rotor core (1) passing through the stator core (2), the gap between the rotor core (1) and the stator core (2) is g, and the depth of the first recess (13) is D, where D≤g / 3.

14. The motor as described in claim 1, characterized in that, It also includes a stator core (2) constructed as an annular ring, the rotor core (1) passing through the stator core (2), the gap between the rotor core (1) and the stator core (2) being g, the height of the first slot (11) being W3, and the shortest width of the magnetic channel (15) being W4. <W4<W3。 15. The motor as described in claim 1, characterized in that, In the second slot (12) located on one side of the symmetry line (113), the outer edge of the rotor core (1) corresponding to the end of the second slot (12) furthest from the symmetry line (113) and the end of the first slot (11) adjacent to it is provided with a second recess (14).

16. The motor as described in claim 15, characterized in that, The second recess (14) includes a first wall surface (141) and a second wall surface (142). The first groove (11) includes a first groove portion (111) located on one side of the symmetry line (113) and a second groove portion (112) located on the other side of the symmetry line (113). The first wall surface (141) is parallel to the side of the first groove portion (111) or the second groove portion (112) adjacent to it. The second wall surface (142) has a preset included angle α with the first wall surface (141).

17. The motor as described in claim 16, characterized in that, The included angle between the first groove (111) and the second groove (112) is β, where 0.5β≤α≤β.

18. The motor as described in claim 16, characterized in that, The distance between the first wall (141) and its parallel side is S. The motor also includes a stator core (2) configured as an annular structure. The rotor core (1) passes through the stator core (2). The gap between the rotor core (1) and the stator core (2) is g, where 0.8g≤S≤11.5g.

19. The motor as claimed in claim 1, characterized in that, It also includes a stator core (2) configured as an annular structure, wherein the inner wall of the stator core (2) is provided with a plurality of third grooves (21) recessed toward the outer edge of the stator core (2) at intervals, the third grooves (21) being configured to accommodate the windings of the stator core (2), and teeth (22) being formed between two adjacent third grooves (21), the teeth (22) including a first tooth portion (221), a second tooth portion (222) and a third tooth portion (223), the first tooth portion (221) being relative to the second tooth portion (223). The third tooth (223) is located away from the central axis of the stator core (2). The third tooth (223) is constructed in a trapezoidal shape. The short side of the third tooth (223) is connected to the first tooth (221), and the long side of the third tooth (223) is connected to the second tooth (222). The distances from the two ends of the inclined side of the third tooth (223) to the side of the second tooth (222) near the rotor core (1) are S1 and S2, respectively, where 2.2≤S2 / S1≤2.

6.

20. An electric motor, characterized in that, Includes a rotor core (1), said rotor core (1) comprising: At least two first slots (11) are configured to accommodate permanent magnets, the at least two first slots (11) being arranged around the central axis of the rotor core (1); and A second groove (12) is provided on the outside of at least one of the at least two first grooves (11), the second groove (12) penetrates the rotor core (1) along the axial direction of the rotor core (1), and the second groove (12) also extends to the outer edge of the rotor core (1); the second groove (12) includes a first part (121) near the first groove (11) and a second part (122) away from the first groove (11), the width of the first part (121) is greater than the width of the second part (122); The first slot (11) is constructed as a symmetrical structure, and the line of symmetry (113) of the first slot (11) is located on a radial line of the rotor core (1). At least one second slot (12) is provided on each side of the line of symmetry (113). In the second slot (12) located on one side of the symmetry line (113), the outer edge of the rotor core (1) corresponding to the end of the second slot (12) furthest from the symmetry line (113) and the end of the first slot (11) adjacent to it is provided with a second recess (14).

21. The motor as described in claim 20, characterized in that, The second recess (14) includes a first wall surface (141) and a second wall surface (142). The first groove (11) includes a first groove portion (111) located on one side of the symmetry line (113) and a second groove portion (112) located on the other side of the symmetry line (113). The first wall surface (141) is parallel to the side of the first groove portion (111) or the second groove portion (112) adjacent to it. The second wall surface (142) has a preset included angle α with the first wall surface (141).

22. The motor as described in claim 21, characterized in that, The included angle between the first groove (111) and the second groove (112) is β, where 0.5β≤α≤β.

23. The motor as described in claim 21, characterized in that, The distance between the first wall (141) and its parallel side is S. The motor also includes a stator core (2) configured as an annular structure. The rotor core (1) passes through the stator core (2). The gap between the rotor core (1) and the stator core (2) is g, where 0.8g≤S≤11.5g.

24. A compressor, characterized in that, Including the motor as described in any one of claims 1 to 23.

25. A refrigeration device, characterized in that, Includes the compressor as described in claim 24.

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