Rotor assembly, rotor assembly, motor and electrical equipment

Abstract

The utility model discloses a rotor assembly, a rotor assembly, a motor and electrical equipment, in the rotor assembly, an edge groove is formed between the outer side of a magnetic steel groove and the outer side of a magnetic steel section, and one end of the edge groove is located at the corner of the magnetic steel groove; the length of each side groove is a and the width of each side groove is b, and a / b is larger than or equal to 4, so that the side grooves at the corner positions of the outer sides of the magnetic steel grooves, namely the positions where stress concentration is likely to be generated, form a long shape, and the magnetic resistance of a reverse magnetic field at the corner areas of the magnetic steel is increased to restrain the demagnetization intensity. And the magnetic steel assembly comprises a plurality of magnetic steel sections correspondingly arranged in the magnetic steel grooves, and the plurality of magnetic steel sections are stacked in the axial direction of the rotor core, so that the stability of the magnetic steel sections at a high rotating speed is ensured. Through the improved design of the rotor assembly, rotor magnetic steel demagnetization is reduced, magnetic steel eddy current loss is reduced, and motor operation efficiency is improved.

Description

Technical Field

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

[0002] Typically, the magnetic domains in a permanent magnet are arranged in an ordered manner after magnetization, aligned with the original magnetic field. However, when exposed to high temperatures, strong reverse magnetic fields, or corrosive and oxidizing environments, this domain arrangement is disrupted, resulting in demagnetization. Demagnetization leads to decreased motor efficiency, increased energy consumption, reduced output torque, speed fluctuations, or stalling. It is also accompanied by increased electromagnetic noise and vibration, and in severe cases, may trigger overload shutdowns, increasing maintenance costs. For example, after demagnetization, the back electromotive force of an air compressor drops sharply, or the driving range of an electric vehicle is significantly shortened, directly impacting equipment reliability and economy. Therefore, there is room for improvement. 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 rotor assembly, a rotor cluster, a motor, and electrical equipment. Through improved design of the rotor assembly, it reduces rotor magnet demagnetization, reduces magnet eddy current losses, and improves motor operating efficiency.

[0004] According to the first aspect of the present invention, a rotor assembly is provided, the rotor assembly comprising a rotor core and a magnet assembly;

[0005] The rotor core has multiple magnetic pole regions formed thereon, and the multiple magnetic pole regions are arranged at intervals in the circumferential direction of the rotor core. Each magnetic pole region is provided with a magnetic steel groove.

[0006] The magnet assembly includes a plurality of magnet segments correspondingly disposed in the magnet slot, and the plurality of magnet segments are stacked along the axial direction of the rotor core;

[0007] Wherein, a side groove is formed between the outer side of the magnetic steel groove and the outer side of the magnetic steel segment, and one end of the side groove is located at the corner of the magnetic steel groove; the side groove has a length a and a width b, and satisfies a / b≥4.

[0008] In some embodiments, the side of the side groove away from the illustrated magnet segment is formed in an arc shape, the radius of curvature of the arc being r and satisfying the following:

[0009] r≥0.3a.

[0010] In some embodiments, the magnet segment has a length c, and the length a of the side groove and the length c of the magnet segment satisfy: 0.2 ≤ a / c ≤ 0.43.

[0011] In some embodiments, each of the magnetic pole regions is provided with at least two magnetic slots, and the outermost magnetic slot is formed between the outer side of the outermost magnetic slot and the outer side of the corresponding magnetic segment.

[0012] In some embodiments, the magnetic pole region includes a first magnetic steel groove group, which has a plurality of magnetic steel grooves. The plurality of magnetic steel grooves are arranged at intervals and symmetrically arranged along the d-axis of the magnetic pole region. A side groove is formed between the outer side of the outermost magnetic steel groove and the outer side of the corresponding magnetic steel segment.

[0013] In some embodiments, the first magnet slot assembly includes:

[0014] Two first magnet slots, the two first magnet slots being symmetrically distributed on both sides of the d-axis and positioned close to the d-axis; and

[0015] Two second magnet slots are symmetrically distributed on both sides of the d-axis and set close to the q-axis of the magnetic pole region;

[0016] The side groove is formed between the outer side of the second magnet groove and the outer side of the corresponding magnet segment.

[0017] In some embodiments, the size of the first magnet groove is smaller than the size of the second magnet groove, and the size of the magnet segment disposed in the first magnet groove is smaller than the size of the magnet segment disposed in the second magnet groove.

[0018] In some embodiments, the width of the first magnet groove and the width of the second magnet groove are the same, and the length of the first magnet groove is less than the length of the second magnet groove; the width of the magnet segment disposed in the first magnet groove is the same as the width of the magnet segment disposed in the second magnet groove, and the length of the magnet segment disposed in the first magnet groove is less than the length of the magnet segment disposed in the second magnet groove.

[0019] In some embodiments, the magnetic pole region includes a plurality of magnetic slot groups arranged at intervals in the radial direction of the rotor core; wherein, in each magnetic slot group, a side slot is formed between the outer side of the outermost magnetic slot and the outer side of the corresponding magnetic segment.

[0020] In some embodiments, each of the magnet slot groups is provided with a plurality of magnet slots, which are spaced apart and arranged symmetrically along the d-axis of the magnetic pole region.

[0021] In some embodiments, each of the magnet slots includes:

[0022] Two first magnet slots, the two first magnet slots being symmetrically distributed on both sides of the d-axis and positioned close to the d-axis; and

[0023] Two second magnet slots are symmetrically distributed on both sides of the d-axis and set close to the q-axis of the magnetic pole region;

[0024] The side groove is formed between the outer side of the second magnet groove and the outer side of the corresponding magnet segment.

[0025] In some embodiments, the size of the first magnet groove is smaller than the size of the second magnet groove, and the size of the magnet segment disposed in the first magnet groove is smaller than the size of the magnet segment disposed in the second magnet groove.

[0026] In some embodiments, the width of the first magnet groove and the width of the second magnet groove are the same, and the length of the first magnet groove is less than the length of the second magnet groove; the width of the magnet segment disposed in the first magnet groove is the same as the width of the magnet segment disposed in the second magnet groove, and the length of the magnet segment disposed in the first magnet groove is less than the length of the magnet segment disposed in the second magnet groove.

[0027] In some embodiments, in the magnet slot assembly, a plurality of magnet slots are arranged in an outwardly opening U-shape along the radial direction of the rotor core.

[0028] In some embodiments, the plurality of magnetic slots in the magnetic slot group include: at least one first magnetic slot and a plurality of second magnetic slots, the first magnetic slot extending circumferentially along the rotor core, the second magnetic slots extending circumferentially and radially along the rotor core, the second magnetic slots being located radially outside the first magnetic slots, and the second magnetic slots being located on the side of the first magnetic slots away from the d-axis.

[0029] This application also discloses a rotor assembly, including the aforementioned rotor components.

[0030] This application also discloses an electric motor, including the aforementioned rotor assembly.

[0031] This application also discloses an electrical device, including the aforementioned motor.

[0032] In the rotor assembly, a side slot is formed between the outer side of the magnet slot and the outer side of the magnet segment, with one end of the side slot located at the corner of the magnet slot. The side slot has a length 'a' and a width 'b', satisfying a / b ≥ 4. This makes the side slot at the outer corner of the magnet slot, where stress concentration is likely to occur, elongated, increasing the magnetic reluctance of the reverse magnetic field at the magnet corner region to suppress the demagnetizing field intensity. The magnet assembly includes multiple magnet segments correspondingly disposed in the magnet slot. These multiple magnet segments are stacked along the axial direction of the rotor core to ensure the stability of the magnet segments at high speeds.

[0033] 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

[0034] Figure 1 This is a schematic diagram of the rotor assembly according to an embodiment of the present utility model.

[0035] Figure 2 yes Figure 1 The diagram shows a top view of the rotor assembly.

[0036] Figure 3 This is a partial structural schematic diagram of one of the magnetic poles of a rotor assembly according to an embodiment of the present invention.

[0037] Figure 4 This is a top view of one of the magnetic poles of a rotor assembly according to an embodiment of the present invention.

[0038] Figure 5 yes Figure 4 A magnified view of part A in the middle.

[0039] Figure 6 This is a top view of one of the magnetic poles of the rotor assembly in a comparative embodiment.

[0040] Figure 7 for Figure 6 The comparative example shows the magnetic field lines in the easily demagnetized region.

[0041] Figure 8 for Figure 6 The comparative example shown is a magnetic field line contour map of another easily demagnetized region.

[0042] Figure 9 for Figure 6 The diagram shows the magnetic field strength distribution in a portion of the magnetic poles in the comparative example.

[0043] Figure 10 This is a schematic diagram of the magnetic field strength distribution in a portion of one of the magnetic poles of the rotor assembly according to an embodiment of the present invention.

[0044] Figure label:

[0045] 100. Rotor assembly;

[0046] 10. Rotor core; 12. Magnet slot; 101. Magnetic pole region; 110. First magnet slot; 120. Second magnet slot; 1101. First side slot; 1201. Second side slot;

[0047] 20. Magnet assembly; 201. Magnet segment. Detailed Implementation

[0048] 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 intended to explain this utility model, and should not be construed as limiting this utility model.

[0049] The following is for reference. Figures 1-5 A rotor assembly 100 according to a first aspect embodiment of the present invention is described.

[0050] The rotor assembly 100 of a first aspect embodiment of the present invention includes a rotor core 10 and a magnet assembly 20. A plurality of magnetic pole regions 101 are formed on the rotor core 10, and the plurality of magnetic pole regions 101 are arranged at intervals in the circumferential direction of the rotor core 10. For example, in this embodiment, six magnetic pole regions 101 are formed on the rotor core 10. Each magnetic pole region 101 is provided with a magnet slot. In specific implementations, each magnetic pole region 101 is typically provided with at least two magnet slots.

[0051] The magnet assembly 20 includes multiple magnet segments 201 correspondingly disposed in the magnet slots. The multiple magnet segments 201 are stacked along the axial direction of the rotor core 10. Dividing the magnet into multiple magnet segments 201 can break the continuous conductive path formed by the large-size magnet. The eddy current loop area in each small segment is reduced, the induced electromotive force is reduced, thereby reducing the eddy current amplitude.

[0052] A side groove is formed between the outer side of the magnet groove and the outer side of the magnet segment 201, with one end of the side groove located at a corner of the magnet groove. The side groove has a length 'a' and a width 'b', satisfying a / b ≥ 4. For example, in some embodiments, a = 4.6 mm, b = 0.93 mm, or a = 6 mm, b = 0.96 mm, or a = 7.4 mm, b = 1.3 mm.

[0053] In practical implementation, the shape of the side groove can be set to approximately trapezoidal, arc-shaped, or other elongated shapes as required, as long as the above-mentioned length-to-width ratio is met. The length of the side groove is its maximum length in its extension direction, and the width of the side groove is its maximum width. Its boundary can be defined by the abrupt change in the shape at both ends of the groove.

[0054] In the rotor assembly 100, a side groove is formed between the outer side of the magnet slot and the outer side of the magnet segment 201, and one end of the side groove is located at the corner of the magnet slot. It can be understood that when the motor rotates, the rotor assembly 100 is subjected to electromagnetic force and centrifugal force. These dynamic loads are more concentrated at the geometric discontinuities of the rotor assembly 100, especially at the geometric discontinuities on its radial outer side, such as the corners of the magnet slots. Since the materials at these positions are prone to deformation when subjected to dynamic loads, the stress concentration phenomenon is more obvious. When the motor rotates at high speed, the centrifugal force will amplify the unbalanced state of the rotor, resulting in dynamic stress in specific areas, such as between the outer side of the magnet slot and the outer side of the magnet segment 201, especially near the corner position of the magnet slot, which may damage the bonding strength between the magnet segment 201 and the rotor core 10 and exacerbate the microscopic deformation of the magnet.

[0055] Mechanical stress will change the arrangement direction of magnetic domains inside the magnet segment 201, hinder the movement of magnetic domain walls, and cause the magnetization intensity to decrease. Local distortion of the magnetic flux path may make the area near the corner position of the magnet slot become a magnetic flux "bottleneck area", accelerating demagnetization.

[0056] Generally, the magnetic domains in a permanent magnet are arranged in an orderly manner and aligned with the original magnetic field after magnetization. However, when exposed to high temperature, strong reverse magnetic field, and easily corroded and oxidized environments, the arrangement of magnetic domains is damaged, resulting in demagnetization. For example, in the case where the main demagnetization environment is a strong reverse magnetic field, due to the requirement of high power density, using the mechanical tolerance and noise attenuation effects brought by the increased air gap. For example, compared with the traditional 0.6 - 0.8 mm design, in the scenario of high power density requirements, the air gap length can be 1.2 mm, which helps to optimize NVH while meeting high magnetic loading. At this time, the no-load air gap magnetic density is as high as 0.8 T (the general electromagnetic scheme is 0.6 - 0.7 T), and the working point of the magnet is close to the inflection point of the demagnetization curve. At this time, the demagnetization resistance of the magnet decreases significantly, so the magnet is extremely prone to demagnetization.

[0057] See Figures 6 to 8 as shown, Figure 6 In a comparative embodiment, it is a top view structural schematic diagram of one magnetic pole of the rotor assembly, Figure 6 which can be understood as the design of the rotor assembly in the related art. Figure 6 The dotted circle in it roughly indicates the demagnetization-prone area. Specifically, Figure 7 and Figure 8 are respectively Figure 6The magnetic field distribution information near the two regions indicated in [the figure], combined with the basic characteristics of magnetic induction lines and magnetic field laws, can be observed from the figure that the demagnetization-prone regions are mainly concentrated in the regions where the magnetic induction lines are relatively sparse and the direction changes greatly. These regions usually appear as blue or lighter-colored parts in the magnetic induction line cloud diagram, forming a sharp contrast with the surrounding red or darker regions where the magnetic induction lines are dense. The density of magnetic induction lines reflects the strength of the magnetic field. In the regions where the magnetic induction lines are sparse, the magnetic field is relatively weak, so these regions are more vulnerable to external factors and thus prone to demagnetization. On the contrary, in the regions where the magnetic induction lines are dense, the magnetic field is stronger and less likely to be demagnetized.

[0058] Through principle exploration and a large number of experiments, the applicant constructed the rotor assembly 100 in the embodiment of the present utility model. Among them, the side groove has a length a and a width b, and satisfies a / b≥4, so that the side groove at the outer corner position of the magnet groove, that is, the position where stress concentration is likely to occur, forms a long shape, increasing the magnetic resistance of the reverse magnetic field in the magnet corner region to suppress the demagnetization field strength.

[0059] See Figure 9 and Figure 10 as shown, which are respectively Figure 6 the schematic diagram of the magnetic field intensity distribution of a partial region of the magnetic pole shown in the comparative example and the schematic diagram of the magnetic field intensity distribution of a partial region of one magnetic pole of the rotor assembly in the embodiment of the present utility model. By comparison, Figure 9 the demagnetization region shown as a high-gradient magnetic field distribution (such as alternating red and blue), the maximum magnetic field intensity reaches 3.09 A / m, and the minimum is only 0.0093 A / m, indicating that there are local magnetic field mutations and demagnetization risks. Figure 10 In [the figure], the maximum magnetic field intensity drops to -3×10 5 A / m, and the minimum reaches -9.9×10 5 A / m. The magnetic field distribution is more uniform (mainly yellow and green), the gradient is significantly reduced, and the probability of triggering demagnetization inflection points is reduced.

[0060] The magnet assembly 20 includes a plurality of magnet segments 201 correspondingly arranged in the magnet grooves. The plurality of magnet segments 201 are stacked along the axial direction of the rotor core 10 to ensure the stability of the magnet segments 201 at high speeds. Selecting to axially divide the magnet into multiple segments can achieve the same effect of reducing the eddy current loss of the magnet as radial segmentation, and at the same time ensure the stability of the magnet segments at high speeds, taking into account the enhancing effect of the long-shaped side groove on suppressing the demagnetization field strength, reducing the eddy current loss of the magnet, and ensuring the stability of the magnet segments 201 at high speeds.

[0061] In some embodiments, the side of the side groove away from the magnet segment is formed into an arc, and the radius of curvature of the arc is r and satisfies:

[0062] r≥0.3a.

[0063] Specifically, the side of the side groove furthest from the magnet segment, i.e., the outer edge of the side groove, is formed in an arc shape to create a geometrically continuous region and reduce the stress concentration factor. Simultaneously, a larger radius of curvature makes it less likely for stress concentration areas to form under dynamic loads. This reduces demagnetization caused by mechanical stress.

[0064] In some embodiments, the magnet segment has a length c, and the length a of the side groove and the length c of the magnet segment 201 satisfy: 0.2 ≤ a / c ≤ 0.43. For example, in specific implementations, the length a of the side groove can be 0.2, 0.3, 0.4 times the length c of the magnet segment 201, etc. The elongated side groove increases the magnetic reluctance of the reverse magnetic field at the corner region of the magnet, thereby suppressing the demagnetizing field strength.

[0065] In some embodiments, each magnetic pole region has at least two magnetic slots, with a side slot formed between the outermost magnetic slot and the outer side of the corresponding magnetic segment. This multi-slot design, through segmented magnetic circuit reconstruction, achieves synergistic optimization of magnetic field harmonic suppression, mechanical stress dispersion, and improved process adaptability while maintaining the overall magnetopotential of the magnetic pole region. Furthermore, as previously analyzed, mechanical stress alters the alignment of magnetic domains within the magnetic segment 201, hindering domain wall movement and reducing magnetization. Local distortion of the magnetic flux path may cause the corner of the magnetic slot to become a magnetic flux "bottleneck," accelerating demagnetization. Therefore, the side slot is formed between the outermost magnetic slot and the outer side of the corresponding magnetic segment. This elongated side slot increases the magnetic reluctance of the reverse magnetic field at the corner region of the magnetic steel, thereby suppressing the demagnetization intensity.

[0066] In some embodiments, the magnetic pole region includes a first magnetic steel groove group, which has a plurality of magnetic steel grooves. The plurality of magnetic steel grooves are arranged at intervals and symmetrically arranged along the d-axis of the magnetic pole region. A side groove is formed between the outer side of the outermost magnetic steel groove and the outer side of the corresponding magnetic steel segment.

[0067] For example, in some embodiments, the first magnet slot assembly includes:

[0068] Two first magnet slots 110 are symmetrically distributed on both sides of the d-axis and positioned close to the d-axis; and

[0069] Two second magnet slots 120 are symmetrically distributed on both sides of the d-axis and set close to the q-axis of the magnetic pole region;

[0070] The side groove is formed between the outer side of the second magnet groove 120 and the outer side of the corresponding magnet segment 201.

[0071] Specifically, the d-axis corresponds to the rotor magnetic pole centerline, where the magnetic field strength is high and relatively stable, with concentrated magnetic field lines. Magnetic field changes in this region are mainly driven by the main magnetic flux, resulting in a low rate of change. The q-axis lies between the two magnetic poles, exhibiting a weaker but more volatile magnetic field. During motor operation, the q-axis magnetic field is more significantly affected by stator current harmonics and rotor rotation, leading to a more pronounced high-frequency alternating magnetic field component. Eddy current losses are proportional to the rate of change of the magnetic field (frequency) and the square of the magnetic field strength amplitude. Due to the high harmonic content and high-frequency components of the magnetic field near the q-axis, eddy current losses are significantly higher near the q-axis than near the d-axis. For example, in high-speed motors, the rotor surface magnetic field generates high-frequency pulsations due to stator cogging effects and current commutation, making the q-axis region a "hotspot" for eddy current losses. Eddy current losses are caused by the ring currents (eddy currents) generated in the magnetic material by the alternating magnetic field, and their energy is dissipated as heat. Increased temperature leads to a decrease in the coercivity of the permanent magnet, weakening its resistance to demagnetization and causing the demagnetization curve inflection point to shift towards the operating region. For example, under high-frequency operating conditions, eddy current losses increase significantly, potentially triggering magnetic domain thermal instability. Therefore, the side groove is formed between the outer side of the second magnet slot 120 and the outer side of the corresponding magnet segment 201. This side groove increases the magnetic reluctance of the reverse magnetic field at the corner of the magnet, thereby suppressing the demagnetizing field strength. It also improves the problem of high-frequency pulsation of the rotor surface magnetic field caused by stator cogging effect and current commutation in high-speed motors, where the q-axis region becomes a "hot spot" for eddy current loss.

[0072] In some embodiments, the size of the first magnet groove is smaller than the size of the second magnet groove, and the size of the magnet segment disposed in the first magnet groove is smaller than the size of the magnet segment disposed in the second magnet groove.

[0073] In each magnetic pole region, the size of the magnetic segment in the slot near the q-axis is larger than that in the slot near the d-axis. This helps reduce the magnetic flux density at the pole edges, minimizes abrupt changes in the local magnetic field, and suppresses the risk of demagnetization. The differentiated size design optimizes the magnetic circuit orientation, reduces magnetic leakage between poles, and improves the effective magnetic flux utilization rate.

[0074] In some embodiments, the width of the first magnet groove 110 and the second magnet groove 120 are the same, and the length of the first magnet groove is less than the length of the second magnet groove; the width of the magnet segment disposed in the first magnet groove is the same as the width of the magnet segment disposed in the second magnet groove, and the length of the magnet segment disposed in the first magnet groove is less than the length of the magnet segment disposed in the second magnet groove.

[0075] Thus, the uniform width design simplifies the processing and assembly of the magnet segments, reducing manufacturing costs. The length difference allows the demagnetizing magnetic field strength borne by the magnet segments to increase in stages, preventing the entire magnetic circuit from simultaneously entering the critical demagnetizing inflection point region.

[0076] In some embodiments, the magnetic pole region includes a plurality of magnetic slot groups arranged at intervals in the radial direction of the rotor core; wherein, in each magnetic slot group, a side slot is formed between the outer side of the outermost magnetic slot and the outer side of the corresponding magnetic segment.

[0077] In some embodiments, each of the magnet slot groups is provided with a plurality of magnet slots, which are spaced apart and arranged symmetrically along the d-axis of the magnetic pole region.

[0078] In some embodiments, each of the magnet slots includes:

[0079] Two first magnet slots, the two first magnet slots being symmetrically distributed on both sides of the d-axis and positioned close to the d-axis; and

[0080] Two second magnet slots are symmetrically distributed on both sides of the d-axis and set close to the q-axis of the magnetic pole region;

[0081] The side groove is formed between the outer side of the second magnet groove and the outer side of the corresponding magnet segment.

[0082] In some embodiments, the size of the first magnet groove is smaller than the size of the second magnet groove, and the size of the magnet segment disposed in the first magnet groove is smaller than the size of the magnet segment disposed in the second magnet groove.

[0083] In some embodiments, the width of the first magnet groove and the width of the second magnet groove are the same, and the length of the first magnet groove is less than the length of the second magnet groove; the width of the magnet segment disposed in the first magnet groove is the same as the width of the magnet segment disposed in the second magnet groove, and the length of the magnet segment disposed in the first magnet groove is less than the length of the magnet segment disposed in the second magnet groove.

[0084] The principle and effect of introducing multiple magnetic steel troughs are similar to those of the single magnetic steel troughs mentioned above, and will not be elaborated separately.

[0085] In some embodiments, the magnet slots in the magnet slot assembly are arranged in a U-shape, opening outwards along the radial direction of the rotor core. This U-shaped arrangement can increase the reluctance torque and torque density of the motor, thereby improving its efficiency. In specific implementations, the magnet slots can also be arranged in other shapes; for example, they can be arranged in a V-shape, opening outwards along the radial direction of the rotor core.

[0086] In some embodiments, the plurality of magnetic slots in the magnetic slot group include: at least one first magnetic slot and a plurality of second magnetic slots, the first magnetic slot extending circumferentially along the rotor core, the second magnetic slots extending circumferentially and radially along the rotor core, the second magnetic slots being located radially outside the first magnetic slots, and the second magnetic slots being located on the side of the first magnetic slots away from the d-axis.

[0087] This application also discloses a rotor assembly, including the aforementioned rotor components.

[0088] This application also discloses an electric motor, including the aforementioned rotor assembly.

[0089] This application also discloses an electrical device including the aforementioned motor. In practice, the electrical device can be any device employing the aforementioned motor, such as passenger vehicles, commercial vehicles, ships, aircraft, etc.

[0090] It is understood that the aforementioned rotor assembly, motor, and electrical equipment in this application inherit the improvements of the aforementioned rotor assembly 100, and therefore the improvements will not be explained separately. Furthermore, since the improvements in this application are mainly in the rotor assembly 100, no separate view is provided to show the aforementioned rotor assembly, motor, and electrical equipment, and they can be understood and implemented according to conventional forms.

[0091] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0093] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0095] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor assembly, characterized in that, The rotor assembly includes a rotor core and a magnet assembly; The rotor core has multiple magnetic pole regions formed thereon, and the multiple magnetic pole regions are arranged at intervals in the circumferential direction of the rotor core. Each magnetic pole region is provided with a magnetic steel groove. The magnet assembly includes a plurality of magnet segments correspondingly disposed in the magnet slot, and the plurality of magnet segments are stacked along the axial direction of the rotor core; Wherein, a side groove is formed between the outer side of the magnetic steel groove and the outer side of the magnetic steel segment, and one end of the side groove is located at the corner of the magnetic steel groove; the side groove has a length a and a width b, and satisfies a / b≥4.

2. The rotor assembly according to claim 1, characterized in that, The side groove away from the magnetic steel section is formed in an arc shape, and the radius of curvature of the arc is r and satisfies: r≥0.3a。 3. The rotor assembly according to claim 1 or 2, characterized in that, The magnet segment has a length c, and the length a of the side groove and the length c of the magnet segment satisfy: 0.2≤a / c≤0.

43.

4. The rotor assembly according to claim 1 or 2, characterized in that, Each of the magnetic pole regions is provided with at least two magnetic slots, and a side slot is formed between the outer side of the outermost magnetic slot and the outer side of the corresponding magnetic segment.

5. The rotor assembly according to claim 1 or 2, characterized in that, The magnetic pole region includes a first magnetic steel groove group, which has a plurality of magnetic steel grooves. The plurality of magnetic steel grooves are arranged at intervals and symmetrically arranged along the d-axis of the magnetic pole region. A side groove is formed between the outer side of the outermost magnetic steel groove and the outer side of the corresponding magnetic steel segment.

6. The rotor assembly according to claim 5, characterized in that, The first magnet slot assembly includes: Two first magnet slots, the two first magnet slots being symmetrically distributed on both sides of the d-axis and positioned close to the d-axis; and Two second magnet slots are symmetrically distributed on both sides of the d-axis and set close to the q-axis of the magnetic pole region; The side groove is formed between the outer side of the second magnet groove and the outer side of the corresponding magnet segment.

7. The rotor assembly according to claim 6, characterized in that, The size of the first magnet groove is smaller than the size of the second magnet groove, and the size of the magnet segment disposed in the first magnet groove is smaller than the size of the magnet segment disposed in the second magnet groove.

8. The rotor assembly according to claim 6, characterized in that, The first magnetic steel groove and the second magnetic steel groove have the same width, and the length of the first magnetic steel groove is less than the length of the second magnetic steel groove; the magnetic steel segment disposed in the first magnetic steel groove has the same width as the magnetic steel segment disposed in the second magnetic steel groove, and the length of the magnetic steel segment disposed in the first magnetic steel groove is less than the length of the magnetic steel segment disposed in the second magnetic steel groove.

9. The rotor assembly according to claim 1, characterized in that, The magnetic pole region includes multiple magnetic slot groups, which are arranged at intervals in the radial direction of the rotor core; wherein, in each magnetic slot group, a side slot is formed between the outermost magnetic slot and the outer side of the corresponding magnetic segment.

10. The rotor assembly according to claim 9, characterized in that, Each of the magnetic steel slot groups is provided with multiple magnetic steel slots, which are arranged at intervals and symmetrically along the d-axis of the magnetic pole region.

11. The rotor assembly according to claim 10, characterized in that, Each of the said magnet slot groups includes: Two first magnet slots, the two first magnet slots being symmetrically distributed on both sides of the d-axis and positioned close to the d-axis; and Two second magnet slots are symmetrically distributed on both sides of the d-axis and set close to the q-axis of the magnetic pole region; The side groove is formed between the outer side of the second magnet groove and the outer side of the corresponding magnet segment.

12. The rotor assembly according to claim 11, characterized in that, The size of the first magnet groove is smaller than the size of the second magnet groove, and the size of the magnet segment disposed in the first magnet groove is smaller than the size of the magnet segment disposed in the second magnet groove.

13. The rotor assembly according to claim 12, characterized in that, The first magnetic steel groove and the second magnetic steel groove have the same width, and the length of the first magnetic steel groove is less than the length of the second magnetic steel groove; the magnetic steel segment disposed in the first magnetic steel groove has the same width as the magnetic steel segment disposed in the second magnetic steel groove, and the length of the magnetic steel segment disposed in the first magnetic steel groove is less than the length of the magnetic steel segment disposed in the second magnetic steel groove.

14. The rotor assembly according to any one of claims 9-13, characterized in that, In the magnet slot group, multiple magnet slots are arranged in an outward-opening U-shape along the radial direction of the rotor core.

15. The rotor assembly according to any one of claims 10-13, characterized in that, The plurality of magnetic slots in the magnetic slot group include: at least one first magnetic slot and a plurality of second magnetic slots, the first magnetic slot extending circumferentially along the rotor core, the second magnetic slots extending circumferentially and radially along the rotor core, the second magnetic slots being located radially outside the first magnetic slots, and the second magnetic slots being located on the side of the first magnetic slots away from the d-axis.

16. A rotor assembly, characterized in that, Includes the rotor assembly as described in any one of claims 1-15.

17. An electric motor, characterized in that, include: The rotor assembly as claimed in claim 16.

18. An electrical device, characterized in that, include: The motor according to claim 17.

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