Motor assembly, compressor and refrigeration apparatus

Abstract

This utility model discloses a motor assembly, a compressor, and refrigeration equipment, relating to the field of compressor technology. The motor assembly includes a rotor core, which includes rotor laminations. Each rotor lamination has multiple magnetic slots, with both ends of the slots offset outwards from the rotor lamination. The rotor lamination has a first magnetic isolation slot and a second magnetic isolation slot located between the d-axis and q-axis. The second magnetic isolation slot is located on the side of the first magnetic isolation slot away from the d-axis, and the end of the second magnetic isolation slot furthest from the rotation axis is closer to the d-axis than the end of the second magnetic isolation slot closer to the rotation axis. The first magnetic isolation slot includes a first segment and a second segment, with the second segment connected to the end of the first segment near the rotation axis. The second segment is offset relative to the first segment in a direction away from the d-axis. The motor assembly of this utility model can reduce the radial electromagnetic force density amplitude and harmonic content, thereby reducing vibration, noise, and improving the efficiency of the motor assembly.

Description

Technical Field

[0001] This utility model relates to the field of refrigeration equipment technology, and in particular to a motor assembly, a compressor and a refrigeration device. Background Technology

[0002] As compressor power increases, the magnetic load on the compressor motor assembly becomes higher, leading to an increase in the amplitude of the radial electromagnetic force density generated by the motor assembly. This causes modal resonance between the motor assembly and the compressor as a whole, resulting in deteriorated noise. Simultaneously, the existing motor assemblies have a high harmonic content in their stator windings, leading to a decrease in motor assembly efficiency. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a motor assembly that can reduce the radial electromagnetic force density amplitude and reduce harmonic content, thereby reducing vibration, lowering noise, and improving the efficiency of the motor assembly.

[0004] This utility model also provides a compressor and a refrigeration device having the above-mentioned motor assembly.

[0005] According to a first aspect of the present invention, a motor assembly includes a stator assembly having an inner hole; a rotor core rotatably disposed in the inner hole, the rotor core including a plurality of rotor laminations stacked axially, each rotor lamination having a plurality of magnetic slots spaced apart circumferentially along the rotor lamination, the two ends of each magnetic slot being offset outward from the rotor lamination; the rotor lamination further includes a first magnetic isolation slot and a second magnetic isolation slot located between the d-axis and the q-axis, the first magnetic isolation slot and the second magnetic isolation slot being located on the side of the magnetic slot away from the rotation axis of the rotor core, and the second magnetic isolation slot being located on the side of the first magnetic isolation slot away from the d-axis. Two magnetic isolation slots are arranged at an angle relative to the d-axis, and the end of the second magnetic isolation slot away from the rotation axis is closer to the d-axis than the end of the second magnetic isolation slot near the rotation axis. The first magnetic isolation slot includes a first slot segment and a second slot segment, the second slot segment being connected to the end of the first slot segment near the rotation axis, and the second slot segment being offset relative to the first slot segment in a direction away from the d-axis. Multiple permanent magnets are respectively installed in multiple magnetic slots. The d-axis is the radial centerline of the magnetic slot, and the q-axis is the angle bisector of two adjacent d-axis segments. The length of the first slot segment is L1, and the length of the second slot segment is L2, satisfying: The angle between the straight line passing through the center of the rotor lamination and tangent to the slot wall of the first magnetic isolation slot on the side away from the d-axis and the d-axis is b; the angle between the straight line passing through the center of the rotor lamination and tangent to the slot wall of the first magnetic isolation slot on the side close to the d-axis and the d-axis is c; the number of winding slots in the stator assembly is Q; the number of pole pairs in the motor assembly is p; and the greatest common divisor of the number of winding slots Q and the number of pole pairs p is G, satisfying: ,and .

[0006] The motor assembly according to the first aspect of the present invention has at least the following beneficial effects: by providing a first magnetic isolation groove and a second magnetic isolation groove, wherein the second magnetic isolation groove is arranged obliquely relative to the d-axis, the first magnetic isolation groove is composed of a first groove segment and a second groove segment offset relative to the first groove segment in a direction away from the d-axis, and the length L1 of the first groove segment and the length L2 of the second groove segment satisfy: and satisfy ,and Because the permeability of air is much lower than that of the main material of the rotor laminations, the magnetic field lines bypass the first and second magnetic isolation slots. Simultaneously, for the magnetic field of the permanent magnet installed in the magnetic slots, the first and second magnetic isolation slots are arranged along the magnetic field lines of the permanent magnet, which helps to reduce the impact on the magnetic flux. Therefore, the first and second magnetic isolation slots can optimize the distribution of magnetic field lines, guiding the magnetic flux distribution in the air gap to be closer to a sine wave, thereby effectively reducing the harmonic content of the air gap magnetic flux density, reducing the amplitude of the radial electromagnetic force density, reducing the risk of resonance, and thus reducing vibration and noise. At the same time, it makes the no-load back EMF waveform also close to a sine wave, thereby reducing the no-load back EMF harmonic content, further reducing vibration and noise, and effectively improving the efficiency of the motor components.

[0007] According to some embodiments of the present invention, the length L1 of the first groove segment and the length L2 of the second groove segment satisfy the following: .

[0008] According to some embodiments of the present invention, the angle between the length direction of the first groove segment and the length direction of the second groove segment is α, which satisfies: 145°≤α≤165°.

[0009] According to some embodiments of this utility model, the number of winding slots Q and the number of pole pairs p satisfy: And 2≤p≤6, 6≤Q≤18.

[0010] According to some embodiments of this utility model, the minimum distance between the wall of the first magnetic isolation groove and the outer peripheral wall of the rotor lamination is 0.35mm to 0.8mm, and the minimum distance between the wall of the first magnetic isolation groove and the wall of the magnet groove is 0.5mm to 2mm; and / or,

[0011] The minimum distance between the wall of the second magnetic isolation groove and the outer peripheral wall of the rotor lamination is 0.35mm to 0.8mm, and the minimum distance between the wall of the second magnetic isolation groove and the wall of the magnet groove is 0.5mm to 2mm.

[0012] According to some embodiments of the present invention, the minimum distance between the wall of the first magnetic shielding groove and the wall of the second magnetic shielding groove is 2mm to 10mm.

[0013] According to some embodiments of the present invention, the magnet slot includes a third slot segment, a fourth slot segment, and a fifth slot segment. The third slot segment is arranged in a direction perpendicular to the d-axis. The fourth slot segment and the fifth slot segment are respectively connected to the two ends of the third slot segment and are arranged symmetrically about the d-axis. The fourth slot segment and the fifth slot segment are respectively offset towards the outside of the rotor lamination relative to the third slot segment.

[0014] According to some embodiments of this utility model, a straight line passing through the end of the third groove segment and parallel to the d-axis is a first straight line. The first straight line passes through the first magnetic isolation groove. The first magnetic isolation groove includes a first portion located on the side of the first straight line away from the d-axis and a second portion located on the side of the first straight line close to the d-axis. In a cross-section perpendicular to the rotation axis, the cross-sectional area of ​​the first portion is S1, and the cross-sectional area of ​​the second portion is S2, satisfying: .

[0015] According to some embodiments of the present invention, the thickness of the rotor lamination is 0.2 mm to 0.35 mm.

[0016] The compressor according to a second aspect of the present invention includes the motor assembly of the first aspect of the present invention.

[0017] The compressor according to the second aspect embodiment of the present invention has at least the following beneficial effects: Since the compressor uses the aforementioned motor assembly, by providing a first magnetic isolation groove and a second magnetic isolation groove, wherein the second magnetic isolation groove is arranged obliquely relative to the d-axis, and the first magnetic isolation groove is composed of a first groove segment and a second groove segment offset relative to the first groove segment in a direction away from the d-axis, the length L1 of the first groove segment and the length L2 of the second groove segment satisfy: and satisfy ,and Because the permeability of air is much lower than that of the main material of the rotor laminations, the magnetic field lines bypass the first and second magnetic isolation slots. Simultaneously, for the magnetic field of the permanent magnet installed in the magnetic slots, the first and second magnetic isolation slots are arranged along the magnetic field lines of the permanent magnet, which helps to reduce the impact on the magnetic flux. Therefore, the first and second magnetic isolation slots can optimize the distribution of magnetic field lines, guiding the magnetic flux distribution in the air gap to be closer to a sine wave, thereby effectively reducing the harmonic content of the air gap magnetic flux density, reducing the amplitude of the radial electromagnetic force density, reducing the risk of resonance, and thus reducing vibration and noise. At the same time, it makes the no-load back EMF waveform also close to a sine wave, thereby reducing the no-load back EMF harmonic content, further reducing vibration and noise, and effectively improving the efficiency of the motor components.

[0018] The refrigeration device according to a third aspect of the present invention includes the compressor of the second aspect of the present invention.

[0019] The refrigeration device according to the third aspect embodiment of the present invention has at least the following beneficial effects: Since the refrigeration device uses the aforementioned compressor, by providing a first magnetic isolation groove and a second magnetic isolation groove, wherein the second magnetic isolation groove is arranged obliquely relative to the d-axis, and the first magnetic isolation groove is composed of a first groove segment and a second groove segment offset relative to the first groove segment in a direction away from the d-axis, the length L1 of the first groove segment and the length L2 of the second groove segment satisfy: and satisfy ,and Because the permeability of air is much lower than that of the main material of the rotor laminations, the magnetic field lines bypass the first and second magnetic isolation slots. Simultaneously, for the magnetic field of the permanent magnet installed in the magnetic slots, the first and second magnetic isolation slots are arranged along the magnetic field lines of the permanent magnet, which helps to reduce the impact on the magnetic flux. Therefore, the first and second magnetic isolation slots can optimize the distribution of magnetic field lines, guiding the magnetic flux distribution in the air gap to be closer to a sine wave, thereby effectively reducing the harmonic content of the air gap magnetic flux density, reducing the amplitude of the radial electromagnetic force density, reducing the risk of resonance, and thus reducing vibration and noise. At the same time, it makes the no-load back EMF waveform also close to a sine wave, thereby reducing the no-load back EMF harmonic content, further reducing vibration and noise, and effectively improving the efficiency of the motor components.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0022] Figure 1 This is a schematic diagram of the rotor lamination structure in an embodiment of this utility model;

[0023] Figure 2 This is a schematic diagram of the first magnetic isolation groove in an embodiment of this utility model;

[0024] Figure 3 This is a partial schematic diagram of the rotor lamination in an embodiment of this utility model;

[0025] Figure 4 This is a bar chart comparing the radial electromagnetic force density of the third order in this embodiment of the invention with that of the prior art at twice the electrical frequency.

[0026] Figure 5 This is a bar chart comparing the radial electromagnetic force density of the third order in this embodiment of the invention with that of the prior art at 8 times the electrical frequency.

[0027] Figure 6 This is a bar chart comparing the radial electromagnetic force density of the third order in this embodiment of the invention with that of the prior art at 16 times the electrical frequency.

[0028] Figure 7 This is a bar chart comparing the harmonic content of the no-load back EMF in this embodiment with that of the prior art.

[0029] Figure label:

[0030] Rotor lamination 100; magnet slot 110; third slot segment 111; fourth slot segment 112; fifth slot segment 113; first magnetic isolation slot 120; first slot segment 121; second slot segment 122; second magnetic isolation slot 130; shaft hole 140;

[0031] The first straight line Z. Detailed Implementation

[0032] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0033] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 limitations on this utility model.

[0034] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0035] In the description of this utility model, unless otherwise explicitly defined, terms such as setting, installing, connecting, assembling, and cooperating should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0036] As the power density of compressors in refrigeration equipment such as air conditioners increases, the magnetic load on the compressor motor assembly becomes higher. When the magnetic load on the motor assembly is high, the radial electromagnetic force density generated by the motor assembly increases, meaning the amplitude of the radial electromagnetic force density increases. This leads to modal resonance between the motor assembly and the compressor as a whole, causing noise degradation. Furthermore, the vibration of the motor assembly is directly proportional to the amplitude of the radial electromagnetic force density. Therefore, an increase in the amplitude of the radial electromagnetic force density of the motor assembly directly leads to intensified vibration and increased noise.

[0037] In addition, in order to reduce the difficulty and cost of winding, existing motor components use fractional slot concentrated windings. The number of slots per pole and per phase of the motor component is fractional. This type of winding has both fractional and integer order harmonics. The high harmonic content leads to a decrease in the efficiency of the motor component.

[0038] Therefore, referring to Figures 1 to 7 As shown, the first aspect of this utility model provides a motor assembly applied in the compressor of a refrigeration equipment, the motor assembly being used to provide power to the piston of the compressor.

[0039] It is understood that the motor assembly includes a stator assembly and a rotor assembly. Specifically, the stator assembly includes a stator core and multiple windings. The stator core is annular and has an inner hole. The stator core includes a stator yoke and multiple stator teeth. The stator yoke is annular, and the multiple stator teeth are connected to the inner circumferential wall of the stator yoke and are arranged at equal intervals along the circumference of the stator core. A winding slot is defined between two adjacent stator teeth, that is, multiple winding slots are arranged at equal intervals along the circumference of the stator core. Generally, the number of stator teeth is equal to the number of windings, that is, the number of winding slots is also equal to the number of windings. The multiple windings are respectively wound on multiple stator teeth and respectively accommodated in two winding slots arranged adjacent to the corresponding stator teeth. The windings are arranged as fractional-slot concentrated windings.

[0040] Reference Figure 1As shown, it can be understood that the rotor assembly is rotatably disposed within the inner bore of the stator assembly. The rotor assembly includes a rotor core and multiple permanent magnets. Specifically, the rotor core is annular and has a shaft hole 140, which is used for the shaft to pass through and to fix the shaft to the rotor core. It is easy to understand that the outer peripheral wall of the rotor assembly and the inner peripheral wall of the stator assembly are arranged radially to define an air gap. The radial direction is the direction perpendicular to the rotation axis of the rotor core from the inner peripheral wall of the stator assembly to the outer peripheral wall of the stator assembly and the reverse direction.

[0041] It is easy to understand that the circumferential direction is the direction around the rotation axis of the rotor assembly, and the axial direction is the direction of the rotation axis of the rotor assembly.

[0042] Reference Figure 1 As shown, it can be understood that the rotor core includes multiple rotor laminations 100 arranged sequentially along the axial direction. Specifically, the rotor laminations 100 are provided with multiple magnet slots 110, which are arranged at equal intervals along the direction surrounding the shaft hole 140, that is, the multiple magnet slots 110 are arranged at equal intervals along the circumference of the rotor laminations 100.

[0043] Reference Figure 1 As shown, it can be understood that the magnet slot 110 is offset outward from both ends of the rotor lamination 100 along its circumferential direction. The outer side is the side of the rotor lamination 100 that is radially away from the shaft hole 140, and the opposite side is the inner side. For example, the magnet slot 110 may be arc-shaped with its arc-shaped opening facing outward from the rotor lamination 100, or it may be U-shaped with its U-shaped opening facing outward from the rotor lamination 100. In other words, the magnet slot 110 may be concave with its concave opening facing outward from the rotor lamination 100.

[0044] Reference Figure 1 As shown, it can be understood that in this embodiment, the magnet slot 110 includes a third slot segment 111, a fourth slot segment 112, and a fifth slot segment 113. Specifically, the third slot segment 111, the fourth slot segment 112, and the fifth slot segment 113 are all straight. The third slot segment 111 is arranged in a direction perpendicular to the radial direction of the rotor lamination 100. The fourth slot segment 112 and the fifth slot segment 113 are respectively connected to the two ends of the third slot segment 111 along the circumference of the rotor lamination 100. The fourth slot segment 112 and the third slot segment 111 can be connected or disconnected, and the fifth slot segment 113 and the third slot segment 111 can also be connected or disconnected.

[0045] Reference Figure 1As shown, it can be understood that the third slot segment 111 has a symmetrical center line arranged radially along the rotor lamination 100 and intersecting the rotation axis of the rotor core. The fourth slot segment 112 and the fifth slot segment 113 are symmetrically arranged about the symmetrical center line of the third slot segment 111. The symmetrical center line of the third slot segment 111 is the radial center line of the magnet slot 110, which is the d-axis. That is, the third slot segment 111 is arranged in a direction perpendicular to the d-axis, and the fourth slot segment 112 and the fifth slot segment 113 are symmetrically arranged about the d-axis.

[0046] It is understandable that the angle bisector of two adjacent d-axis is the q-axis, which can also be understood as the symmetrical center line of two adjacent magnetic slots 110. The q-axis intersects with the rotation axis of the rotor core.

[0047] Reference Figure 1 As shown, it can be understood that the fourth slot 112 and the fifth slot 113 are offset from the third slot 111 to the outside of the rotor lamination 100. That is to say, the magnet slot 110 has an approximately U-shaped structure and the opening faces the outside of the rotor lamination 100. The angle between the arrangement direction of the third slot 111 and the arrangement direction of the fourth slot 112 is an obtuse angle.

[0048] Reference Figure 1 As shown, multiple permanent magnets are respectively installed in multiple magnetic slots 110. Each permanent magnet has a three-segment structure and is installed in the third slot 111, the fourth slot 112, and the fifth slot 113, respectively. The permanent magnet in each magnetic slot 110 serves as one magnetic pole of the motor assembly. By using a three-segment permanent magnet structure, eddy current losses in the magnets can be reduced, thereby improving the efficiency of the motor assembly.

[0049] Reference Figure 1 As shown, it can be understood that the rotor lamination 100 is also provided with a first magnetic isolation groove 120 and a second magnetic isolation groove 130. Specifically, a first magnetic isolation groove 120 and a second magnetic isolation groove 130 are provided between each adjacent d-axis and q-axis. The two first magnetic isolation grooves 120 located on both sides of the d-axis are arranged symmetrically about the d-axis, and the two second magnetic isolation grooves 130 located on both sides of the d-axis are arranged symmetrically about the d-axis.

[0050] The first magnetic isolation slot 120 and the second magnetic isolation slot 130 located between adjacent d-axis and q-axis are described in detail below.

[0051] Reference Figure 1As shown, it can be understood that both the first magnetic isolation slot 120 and the second magnetic isolation slot 130 are located on the side of the magnet slot 110 away from the rotation axis of the rotor core; that is, both the first magnetic isolation slot 120 and the second magnetic isolation slot 130 are located on the outer side of the magnet slot 110. The first magnetic isolation slot 120 and the second magnetic isolation slot 130 are arranged at intervals along a direction perpendicular to the d-axis, wherein the second magnetic isolation slot 130 is located on the side of the first magnetic isolation slot 120 away from the d-axis; that is, the first magnetic isolation slot 120 is closer to the d-axis than the second magnetic isolation slot 130.

[0052] Reference Figure 1 As shown, it can be understood that the second magnetic isolation slot 130 is straight and located outside the third slot segment 111 along the d-axis. Specifically, the second magnetic isolation slot 130 is arranged at an angle relative to the d-axis, and the end of the second magnetic isolation slot 130 away from the rotation axis of the rotor core is closer to the d-axis than the end of the second magnetic isolation slot 130 closer to the rotation axis of the rotor core; that is, the outer end of the second magnetic isolation slot 130 is closer to the d-axis than the inner end. Therefore, the arrangement direction of the second magnetic isolation slot 130 matches the arrangement direction of the magnetic field lines of the permanent magnet around the second magnetic isolation slot 130, that is, the second magnetic isolation slot 130 is arranged along the magnetic field lines of the permanent magnet around the second magnetic isolation slot 130.

[0053] Reference Figure 1 and Figure 2 As shown, it can be understood that the first magnetic isolation slot 120 is located outside the connection point of the third slot segment 111 and the fourth slot segment 112 along the d-axis. Specifically, the first magnetic isolation slot 120 includes a first slot segment 121 and a second slot segment 122, both of which are straight. The first slot segment 121 is arranged parallel to the d-axis, and the second slot segment 122 is connected to the end of the first slot segment 121 near the rotation axis of the rotor core, i.e., the second slot segment 122 is connected to the inner end of the first slot segment 121. The second slot segment 122 is offset relative to the first slot segment 121 in a direction away from the d-axis. In other words, the second slot segment 122 is inclined relative to the d-axis, and the end of the second slot segment 122 away from the rotation axis of the rotor core is closer to the d-axis than the end of the second slot segment 122 near the rotation axis of the rotor core. The angle between the arrangement direction of the second slot segment 122 and the arrangement direction of the first slot segment 121 is an obtuse angle. Therefore, the shape of the first magnetic isolation groove 120 is adapted to the magnetic field line distribution of the magnetic field generated by the permanent magnet with the above-mentioned three-segment structure, so that the first groove segment 121 and the second groove segment 122 of the first magnetic isolation groove 120 are arranged along the magnetic field lines of the permanent magnet around the first magnetic isolation groove 120.

[0054] In other embodiments, the first slot segment 121 can be arranged at an angle relative to the d-axis, so that the first slot segment 121 is arranged along the magnetic field lines of the magnetic field around the permanent magnet.

[0055] Reference Figure 1 As shown, it can be understood that the interior of the first magnetic isolation groove 120 and the interior of the second magnetic isolation groove 130 are filled with air, and the magnetic permeability of air is much lower than that of the main material of the rotor lamination 100. Therefore, by setting the first magnetic isolation groove 120 and the second magnetic isolation groove 130, the magnetic field lines of the magnetic field generated by the permanent magnet bypass the first magnetic isolation groove 120 and the second magnetic isolation groove 130, thereby optimizing the distribution of magnetic field lines and guiding the distribution of magnetic flux in the air gap to be closer to a sine wave. This effectively reduces the harmonic content of the air gap magnetic flux density, reduces the amplitude of the radial electromagnetic force density, reduces the risk of modal resonance between the motor assembly and the compressor, and thus reduces vibration and noise.

[0056] It is easy to understand that the radial electromagnetic force is generated by the combined action of the fundamental wave and harmonics of the air gap magnetic field. This scheme mainly reduces the radial electromagnetic force density amplitude by reducing the radial electromagnetic force generated by the harmonics.

[0057] Understandably, by adjusting the distribution of magnetic flux in the air gap, the waveform of the no-load back EMF is made closer to a sine wave, thereby reducing the harmonic content of the no-load back EMF, further reducing vibration and noise, and effectively improving the efficiency of the motor components.

[0058] It is understandable that since the first magnetic isolation slot 120 and the second magnetic isolation slot 130 are both arranged along the magnetic field lines of the permanent magnet, the weakening effect of the first magnetic isolation slot 120 and the second magnetic isolation slot 130 on the magnetic flux is effectively reduced, thereby reducing the influence of the first magnetic isolation slot 120 and the second magnetic isolation slot 130 on the magnetic flux, which is beneficial to ensuring the efficiency of the motor assembly.

[0059] Reference Figure 2 As shown, it can be understood that the length of the first slot segment 121 is defined as L1, and the length of the second slot segment 122 is defined as L2, satisfying: .For example, The value is 1.5, 2 or 3, etc. By reasonably adjusting the length ratio of the first slot segment 121 and the second slot segment 122, the shape of the first magnetic isolation slot 120 is optimized, so that the shape of the first magnetic isolation slot 120 is more suitable for the magnetic field line distribution of the permanent magnet with an approximately U-shaped structure. On the one hand, the weakening effect of the first magnetic isolation slot 120 on the magnetic flux is reduced, and on the other hand, the magnetic flux distribution in the air gap can be better guided to be closer to a sine wave, reducing harmonics, thereby reducing vibration and noise.

[0060] Reference Figure 2As shown, it can be understood that the angle between the length direction of the first slot segment 121 and the length direction of the second slot segment 122 is defined as α, satisfying: 145°≤α≤165°. Angle α can be understood as the angle between two adjacent slot walls of the first slot segment 121 and the second slot segment 122. Angle α can be 145°, 150°, 160°, or 165°, etc. By reasonably adjusting the angle between the length direction of the first slot segment 121 and the length direction of the second slot segment 122, the shape of the first magnetic isolation slot 120 is further optimized, thereby reducing the weakening effect of the first magnetic isolation slot 120 on magnetic flux and reducing vibration and noise.

[0061] Reference Figure 3 As shown, it can be understood that the angle between the straight line passing through the center of the rotor lamination 100 and tangent to the groove wall of the first magnetic isolation groove 120 on the side away from the d-axis and the d-axis is defined as b. That is, the angle between the straight line tangent to the groove wall of the inner end of the second groove segment 122 and passing through the center of the rotor lamination 100 and the d-axis is b. The angle between the straight line passing through the center of the rotor lamination 100 and tangent to the groove wall of the first magnetic isolation groove 120 on the side close to the d-axis and the d-axis is c. That is, the angle between the straight line tangent to the groove wall of the outer end of the first groove segment 121 and passing through the center of the rotor lamination 100 and the d-axis is c. The units of angle b and angle c are both °.

[0062] Reference Figure 2 As shown, it is understandable that the number of winding slots is defined as Q, the number of pole pairs of the motor assembly is p, and the greatest common divisor of the number of winding slots Q and the number of pole pairs p is G.

[0063] Reference Figure 3 As shown, it can be understood that the included angle b and the greatest common divisor G satisfy: And the included angle c and the greatest common divisor G satisfy: Therefore, by limiting The included angle b is limited by combining the greatest common divisor of the number of winding slots and the number of pole pairs of the motor assembly. That is, by combining the specific number of winding slots and the number of pole pairs of the motor assembly, the included angle b is limited to a reasonable range. This further optimizes the length of the second slot segment 122 and the maximum distance between the second slot segment 122 and the d-axis. At the same time, by limiting... The included angle c is limited by combining the greatest common divisor of the number of winding slots and the number of pole pairs of the motor assembly. That is, by combining the specific number of winding slots and the number of pole pairs of the motor assembly, the included angle c is limited to a reasonable range, further optimizing the length of the first slot segment 121. For example The value can be 0.4, 0.45, 0.6, or 0.7, etc. The value can be 0.2, 0.25, 0.4, or 0.5, etc.

[0064] Therefore, by combining a specific number of winding slots and pole pairs of the motor assembly, the shape of the first magnetic isolation slot 120 and the size and position of the space occupied by the first magnetic isolation slot 120 on the rotor lamination 100 are further optimized, so that the shape of the first magnetic isolation slot 120 and the size and position of the space occupied are more adapted to the magnetic field line distribution of the magnetic field of the approximately U-shaped permanent magnet. On the one hand, the weakening effect of the first magnetic isolation slot 120 on the magnetic flux is reduced, and on the other hand, the magnetic flux distribution in the air gap can be better guided to be closer to a sine wave, reducing harmonics, thereby reducing vibration and noise.

[0065] It is understood that in this embodiment, the number of winding slots Q and the number of pole pairs p satisfy the following conditions: And 2≤p≤6, 6≤Q≤18. For example, if the number of winding slots Q is 9, the number of magnetic poles in the motor assembly is 6, and the number of pole pairs p is 3; or, if the number of winding slots Q is 12, the number of magnetic poles in the motor assembly is 8, and the number of pole pairs p is 4. This optimizes the slot-to-pole ratio of the motor assembly, thereby improving the efficiency of the motor assembly.

[0066] Reference Figure 3 As shown, it can be understood that the minimum distance L3 between the groove wall of the first magnetic isolation groove 120 and the outer peripheral wall of the rotor lamination 100 is 0.35mm to 0.8mm, and the minimum distance L4 between the groove wall of the first magnetic isolation groove 120 and the groove wall of the magnet groove 110 is 0.5mm to 2mm.

[0067] It is easy to understand that by providing a first magnetic isolation groove 120 in the rotor lamination 100, magnetic bridges are formed between the first magnetic isolation groove 120 and the magnet slot 110, and between the first magnetic isolation groove 120 and the outer peripheral wall of the rotor lamination 100. By limiting the minimum distance between the groove wall of the first magnetic isolation groove 120 and the outer peripheral wall of the rotor lamination 100, and the minimum distance between the groove wall of the first magnetic isolation groove 120 and the groove wall of the magnet slot 110, the position and overall length of the first magnetic isolation groove 120 are optimized. This satisfies the function of guiding the magnetic flux distribution in the air gap to be closer to a sine wave, reducing harmonics, reducing vibration, and reducing noise. At the same time, the width of the magnetic bridge located between the first magnetic isolation groove 120 and the magnet slot 110, and the width of the magnetic bridge located between the first magnetic isolation groove 120 and the outer peripheral wall of the rotor lamination 100, are ensured, thereby improving the structural strength of the rotor lamination 100. For example, the minimum distance between the wall of the first magnetic isolation groove 120 and the outer peripheral wall of the rotor lamination 100 can be 0.35mm, 0.5mm, 0.75mm, or 0.8mm, etc., and the minimum distance between the wall of the first magnetic isolation groove 120 and the wall of the magnet groove 110 can be 0.5mm, 0.9mm, 1.2mm, or 2mm, etc.

[0068] Reference Figure 3As shown, it can be understood that the minimum distance L5 between the groove wall of the second magnetic isolation groove 130 and the outer peripheral wall of the rotor lamination 100 is 0.35mm to 0.8mm, and the minimum distance L6 between the groove wall of the second magnetic isolation groove 130 and the groove wall of the magnet groove 110 is 0.5mm to 2mm.

[0069] It is easy to understand that by providing a second magnetic isolation groove 130 in the rotor lamination 100, magnetic bridges are formed between the second magnetic isolation groove 130 and the magnet slot 110, and between the second magnetic isolation groove 130 and the outer peripheral wall of the rotor lamination 100. By limiting the minimum distance between the groove wall of the second magnetic isolation groove 130 and the outer peripheral wall of the rotor lamination 100, and the minimum distance between the groove wall of the second magnetic isolation groove 130 and the groove wall of the magnet slot 110, the position and overall length of the second magnetic isolation groove 130 are optimized. This satisfies the function of guiding the magnetic flux distribution in the air gap to be closer to a sine wave, reducing harmonics, reducing vibration, and reducing noise. At the same time, the width of the magnetic bridge located between the second magnetic isolation groove 130 and the magnet slot 110, and the width of the magnetic bridge located between the second magnetic isolation groove 130 and the outer peripheral wall of the rotor lamination 100, are ensured, thereby improving the structural strength of the rotor lamination 100. For example, the minimum distance between the groove wall of the second magnetic isolation groove 130 and the outer peripheral wall of the rotor lamination 100 can be 0.35mm, 0.5mm, 0.75mm, or 0.8mm, etc., and the minimum distance between the groove wall of the second magnetic isolation groove 130 and the groove wall of the magnet groove 110 can be 0.5mm, 0.9mm, 1.2mm, or 2mm, etc.

[0070] It is understood that in some other embodiments, the minimum distance between the wall of the first magnetic isolation groove 120 and the outer peripheral wall of the rotor lamination 100 is 0.35mm to 0.8mm, and the minimum distance between the wall of the first magnetic isolation groove 120 and the wall of the magnet groove 110 is 0.5mm to 2mm. Alternatively, the minimum distance between the wall of the second magnetic isolation groove 130 and the outer peripheral wall of the rotor lamination 100 is 0.35mm to 0.8mm, and the minimum distance between the wall of the second magnetic isolation groove 130 and the wall of the magnet groove 110 is 0.5mm to 2mm. Further details are omitted here.

[0071] Reference Figure 3As shown, it can be understood that the minimum distance L7 between the wall of the first magnetic isolation slot 120 and the wall of the second magnetic isolation slot 130 is 2mm to 10mm. Similarly, by setting the first magnetic isolation slot 120 and the second magnetic isolation slot 130 at intervals on the rotor lamination 100, a magnetic bridge is formed between the first magnetic isolation slot 120 and the second magnetic isolation slot 130. By limiting the minimum distance between the wall of the first magnetic isolation slot 120 and the wall of the second magnetic isolation slot 130, the relative position between the first magnetic isolation slot 120 and the second magnetic isolation slot 130 is optimized, which satisfies the function of guiding the magnetic flux distribution in the air gap to be closer to a sine wave, reducing harmonics, reducing vibration, and reducing noise. At the same time, the width of the magnetic bridge located between the first magnetic isolation slot 120 and the second magnetic isolation slot 130 is ensured, thereby improving the structural strength of the rotor lamination 100. In addition, it is also beneficial to reduce the magnetic flux saturation of the magnetic bridge located between the first magnetic isolation slot 120 and the second magnetic isolation slot 130, thereby improving the efficiency of the motor assembly.

[0072] Reference Figure 3 As shown, it can be understood that the straight line passing through the end of the third slot segment 111 near the end of the fourth slot segment 112 and parallel to the d-axis is defined as the first straight line Z. In this embodiment, the first straight line Z passes through the first magnetic isolation slot 120. The first magnetic isolation slot 120 includes a first part and a second part, wherein the first part is located on the side of the first straight line Z away from the d-axis, and the second part is located on the side of the first straight line Z near the d-axis. On a cross-section perpendicular to the rotation axis of the rotor core, the cross-sectional area of ​​the first part is defined as S1, and the cross-sectional area of ​​the second part is defined as S2, satisfying: .

[0073] It is understandable that the first straight line Z can be interpreted as the boundary line between the third slot segment 111 and the fourth slot segment 112. By limiting the ratio of the cross-sectional areas of the two parts of the first magnetic isolation slot 120 located on either side of the first straight line Z, the area sizes of the first and second parts of the first magnetic isolation slot 120 are optimized. This allows the first and second parts to adapt to the magnetic field lines of the two permanent magnets installed in the fourth slot segment 112 and the third slot segment 111, respectively. This better guides the magnetic flux distribution in the air gap to be closer to a sine wave, reducing harmonics, vibration, and noise. For example, The value is 0.2, 0.4, 0.5 or 0., etc.

[0074] Understandably, besides the amplitude of the radial electromagnetic force density of the motor assembly affecting its vibration and noise, the order of the radial electromagnetic force density also influences its vibration and noise. Specifically, the vibration of the motor assembly can be approximated as being inversely proportional to the fourth power of the order of the radial electromagnetic force density; that is, the lower the order of the radial electromagnetic force density, the greater its impact on the vibration of the motor assembly. Therefore, studying low-order radial electromagnetic force densities can effectively reflect the vibration and noise levels of the motor assembly.

[0075] Reference Figure 4 As shown, it is understandable that Figure 4 The bar chart shows a comparison between the third-order radial electromagnetic force density of this scheme and the prior art scheme at twice the electrical frequency (fe). The prior art scheme omits the first magnetic isolation groove 120 and the second magnetic isolation groove 130. The chart shows that at twice the electrical frequency, the third-order radial electromagnetic force density of this scheme is 23.7 kN / mm². 2 It reduces the pressure by 1 kN / mm compared to existing technologies. 2 Therefore, this solution can significantly reduce the radial electromagnetic force density of the third order, that is, reduce the amplitude of the radial electromagnetic force density, thereby reducing the vibration of the motor assembly and reducing noise.

[0076] Reference Figure 5 As shown, it is understandable that Figure 5 This is a bar chart comparing the third-order radial electromagnetic force density of our proposed solution with that of existing technologies at eight times the electrical frequency. The chart shows that at eight times the electrical frequency, the third-order radial electromagnetic force density of our proposed solution is 0.9 kN / mm². 2 It reduces the pressure by 0.2 kN / mm compared to existing technologies. 2 Therefore, this solution can significantly reduce the radial electromagnetic force density of the third order, that is, reduce the amplitude of the radial electromagnetic force density, thereby reducing the vibration of the motor assembly and reducing noise.

[0077] Reference Figure 6 As shown, it is understandable that Figure 6 This is a bar chart comparing the third-order radial electromagnetic force density of our proposed solution with that of existing technologies at 16 times the electrical frequency. The chart shows that at 16 times the electrical frequency, the third-order radial electromagnetic force density of our proposed solution is 0.15 kN / mm². 2 This reduces the pressure by 0.03 kN / mm compared to existing technologies. 2 Therefore, this solution can significantly reduce the radial electromagnetic force density of the third order, that is, reduce the amplitude of the radial electromagnetic force density, thereby reducing the vibration of the motor assembly and reducing noise.

[0078] Reference Figures 4 to 6As shown, it can be understood that the third-order radial electromagnetic force density of this scheme decreases regardless of whether it is at 2 times, 8 times, or 16 times the electrical frequency, thereby effectively reducing the vibration of the motor assembly and lowering noise. Furthermore, the third-order radial electromagnetic force density decreases with increasing electrical frequency, resulting in lower noise.

[0079] Reference Figure 7 As shown, it is understandable that Figure 7 This is a bar chart comparing the no-load back EMF harmonic content of our proposed solution with that of existing technologies. The chart shows that the no-load back EMF harmonic content of our proposed solution is 2.9%, a reduction of 2.3 percentage points compared to existing technologies. This demonstrates that our proposed solution can significantly reduce no-load back EMF harmonics, thereby reducing vibration and noise, and effectively improving the efficiency of the motor components.

[0080] Understandably, the thickness of the rotor lamination 100 is 0.2 mm to 0.35 mm, thereby optimizing the material usage of the rotor lamination 100 and improving the performance of the motor assembly at a lower cost.

[0081] The compressor of the second aspect of this utility model includes the motor assembly of the first aspect of this utility model.

[0082] Because the compressor adopts all the technical solutions of the motor assembly in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0083] The refrigeration equipment of the third aspect of this utility model includes the compressor of the second aspect of this utility model. The refrigeration equipment can be an air conditioner, a cold drink machine, etc.

[0084] Since the refrigeration equipment adopts all the technical solutions of the compressor in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments.

[0085] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. An electric machine assembly, characterized by include: The stator assembly has an inner hole; A rotor core is rotatably disposed in the inner hole. The rotor core includes a plurality of rotor laminations stacked along the axial direction. Each rotor lamination is provided with a plurality of magnetic slots. The plurality of magnetic slots are arranged at intervals along the circumference of the rotor laminations, and the two ends of the magnetic slots are respectively offset to the outside of the rotor laminations. The rotor lamination is further provided with a first magnetic isolation groove and a second magnetic isolation groove located between the d-axis and the q-axis. The first magnetic isolation groove and the second magnetic isolation groove are located on the side of the magnet groove away from the rotation axis of the rotor core, and the second magnetic isolation groove is located on the side of the first magnetic isolation groove away from the d-axis. The second magnetic isolation groove is inclined relative to the d-axis, and the end of the second magnetic isolation groove away from the rotation axis is closer to the d-axis than the end of the second magnetic isolation groove close to the rotation axis. The first magnetic isolation groove includes a first groove segment and a second groove segment. The second groove segment is connected to the end of the first groove segment close to the rotation axis, and the second groove segment is offset relative to the first groove segment in a direction away from the d-axis. Multiple permanent magnets are respectively installed in multiple magnetic steel slots; Wherein, the d-axis is the radial center line of the magnetic groove, and the q-axis is the angle bisector of two adjacent d-axis; The length of the first slot section is L1, and the length of the second slot section is L2, satisfying: ; The angle between the straight line passing through the center of the rotor lamination and tangent to the slot wall of the first magnetic isolation slot on the side away from the d-axis and the d-axis is b; the angle between the straight line passing through the center of the rotor lamination and tangent to the slot wall of the first magnetic isolation slot on the side close to the d-axis and the d-axis is c; the number of winding slots in the stator assembly is Q; the number of pole pairs in the motor assembly is p; and the greatest common divisor of the number of winding slots Q and the number of pole pairs p is G, satisfying: ,and .

2. The electric machine assembly of claim 1, wherein: The length LI of the first slot section and the length L2 of the second slot section satisfy: .

3. An electric machine assembly according to claim 1 or 2, characterized in that: The angle between the length direction of the first groove segment and the length direction of the second groove segment is α, which satisfies: 145°≤a≤165°.

4. The electric machine assembly of claim 1, wherein: The number Q of the wire grooves and the number p of the pole pairs satisfy: , and 2≤p≤6, 6≤Q≤18.

5. The electric machine assembly of claim 1, wherein: The minimum distance between the wall of the first magnetic isolation groove and the outer peripheral wall of the rotor lamination is 0.35mm to 0.8mm, and the minimum distance between the wall of the first magnetic isolation groove and the wall of the magnet groove is 0.5mm to 2mm. And / or, The minimum distance between the wall of the second magnetic isolation groove and the outer peripheral wall of the rotor lamination is 0.35mm to 0.8mm, and the minimum distance between the wall of the second magnetic isolation groove and the wall of the magnet groove is 0.5mm to 2mm.

6. The electric machine assembly of claim 1, wherein: The minimum distance between the wall of the first magnetic shielding groove and the wall of the second magnetic shielding groove is 2mm to 10mm.

7. The electric machine assembly of claim 1, wherein: The magnet slot includes a third slot segment, a fourth slot segment, and a fifth slot segment. The third slot segment is arranged in a direction perpendicular to the d-axis. The fourth and fifth slot segments are respectively connected to the two ends of the third slot segment and are arranged symmetrically about the d-axis. The fourth and fifth slot segments are respectively offset towards the outside of the rotor lamination relative to the third slot segment.

8. The electric machine assembly of claim 7, wherein: A straight line passing through the end of the third groove segment and parallel to the d-axis is a first straight line. This first straight line passes through the first magnetically shielding groove. The first magnetically shielding groove includes a first portion located on the side of the first straight line away from the d-axis and a second portion located on the side of the first straight line closer to the d-axis. In a cross-section perpendicular to the rotation axis, the cross-sectional area of ​​the first portion is S1, and the cross-sectional area of ​​the second portion is S2, satisfying the following: .

9. The electric machine assembly of claim 1, wherein: The thickness of the rotor laminations is 0.2 mm to 0.35 mm.

10. Compressor, characterized in that Includes the motor assembly as described in any one of claims 1 to 9.

11. A refrigeration appliance characterised in that, Includes the compressor as described in claim 10.

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