Rotor and motor

Abstract

The invention discloses a rotor and a motor, the rotor comprises a rotor core and magnetic steel, the rotor core comprises a plurality of rotor punching sheets, the rotor punching sheets define a plurality of magnetic steel groove groups, each magnetic steel groove group defines a magnetic pole, and each magnetic steel groove group is provided with a plurality of magnetic steel grooves; wherein the magnetic steel groove group comprises a plurality of layers of magnetic steel grooves which are sequentially arranged along the radial direction, each layer of magnetic steel groove is symmetrically arranged relative to the center line of the magnetic pole, a reference circle is defined by the connecting line of each layer of magnetic steel groove, the circle centers of the plurality of reference circles are positioned on the extension line of the center line of the magnetic pole, and the distance between the axis of the rotor core and the circle center of the reference circle is D1, the outer diameter of the rotor core is D2, and D1 is larger than or equal to D2. Each layer of magnetic steel is arranged in a circular arc shape, so that the magnetic gathering effect is improved; the centers of the reference circles are all located on the extension line of the center line of the magnetic pole, and D1 is greater than or equal to D2, so that the concentration effect of the magnetic field on the air gap side and the stator side is improved, the sine property of the air gap magnetic field is improved, and the torque pulsation of the motor is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of electric motor technology, and more particularly to a rotor and an electric motor. Background Technology

[0002] Permanent magnet synchronous motors have the advantages of high efficiency and low cost. In practical applications, there are usually magnetic slots in the rotor, and permanent magnets are embedded in the magnetic slots to make full use of magnetic reluctance torque.

[0003] In related technologies, an unreasonable arrangement of magnets results in poor magnetization and an inability to concentrate them on the air gap and stator sides, which can easily lead to large torque pulsation in the motor and affect the motor's operational stability. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention proposes a rotor that has good magnetic focusing effect and helps to reduce torque ripple in the motor.

[0005] According to an embodiment of the present invention, a rotor includes: a rotor core comprising a plurality of rotor laminations stacked axially, the rotor laminations defining a plurality of magnetic slot groups, each magnetic slot group defining a magnetic pole, and each magnetic slot group having a plurality of magnetic slots; and magnets disposed within the magnetic slots; wherein the magnetic slot groups comprise: at least two layers of magnetic slots arranged radially, each layer of magnetic slots being symmetrically arranged relative to the center line of the magnetic pole, the line connecting each layer of magnetic slots defining a reference circle, the centers of the plurality of reference circles being located on the extension line of the center line of the magnetic pole, the distance between the axis of the rotor core and the center of the reference circle being D1, and the outer diameter of the rotor core being D2, where D1 ≥ D2.

[0006] According to an embodiment of the present invention, the rotor defines a reference circle by connecting the slots of each layer of magnets, so that each layer of magnets can be arranged in an arc shape, thereby allowing the magnetic fields formed by the magnets to be superimposed and improving the magnetization effect. Furthermore, by ensuring that the centers of multiple reference circles are all located on the extension line of the magnetic pole center line, and that the distance between the axis of the rotor core and the center of the reference circle is greater than or equal to the outer diameter of the rotor core, the effect of magnetic field concentration on the air gap side and the stator side is improved, which is beneficial to improving the sinusoidal nature of the air gap magnetic field, thereby reducing harmonic interference, effectively reducing the torque pulsation of the motor, and improving the operating stability of the motor.

[0007] According to some embodiments of the present invention, the radial dimensions of the magnets in the plurality of magnet slots in the same layer are consistent.

[0008] According to some embodiments of the present invention, the length edge of each of the magnetic slots is tangent to or coincides with the reference circle.

[0009] According to some embodiments of the present invention, each of the magnet slots includes: a first slot segment and a second slot segment, and each magnet includes: a first magnet segment and a second magnet segment, wherein the first magnet segment is disposed in the first slot segment and the second magnet segment is disposed in the second slot segment.

[0010] According to some embodiments of the present invention, a partition bar is provided between the first groove segment and the second groove segment.

[0011] According to some embodiments of the present invention, the rotor lamination is provided with a magnetic barrier groove, the magnetic barrier groove including: a first magnetic barrier groove located on at least one side edge of the width of each of the magnet slots, the first magnetic barrier groove communicating with the magnet slot.

[0012] According to some embodiments of the present invention, the magnetic barrier groove further includes: a second magnetic barrier groove formed on the outermost magnetic steel groove in the layer of magnetic steel grooves adjacent to the axis, on the side of the width edge away from the magnetic pole center line, wherein the second magnetic barrier groove is in communication with the magnetic steel groove.

[0013] According to some embodiments of the present invention, the magnetic barrier groove further includes a third magnetic barrier groove located radially outside the second magnetic barrier groove.

[0014] According to some embodiments of the present invention, the edge corner regions of the first magnetic barrier groove, the second magnetic barrier groove, and the third magnetic barrier groove are all constructed with rounded transitions.

[0015] The second objective of this invention is to provide an electric motor.

[0016] The motor according to an embodiment of the present invention includes the rotor described above.

[0017] The motor has the same advantages as the rotor mentioned above, and will not be repeated here.

[0018] Additional aspects and advantages of the 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

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 An axial schematic diagram of a rotor core provided for some embodiments of the present invention; Figure 2 Schematic diagram of a partial rotor structure provided for some embodiments of the present invention Figure 1 The circle shown by the dashed line is the reference circle; Figure 3Schematic diagram of a partial rotor structure provided for some embodiments of the present invention Figure 2 .

[0020] Figure label: Rotor 100 Rotor core 110, rotor laminations 111 Magnet steel trough assembly 112 Magnetic steel channel 1121, first channel segment 11211, second channel segment 11212 Magnetic pole 113 Magnet 120, First Magnet Segment 121, Second Magnet Segment 122 140mm partition bar First magnetic barrier groove 151, second magnetic barrier groove 152, and third magnetic barrier groove 153. Detailed Implementation

[0021] Embodiments of the present invention 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 the present invention, and should not be construed as limiting the present invention.

[0022] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] The following reference Figures 1 to 3A rotor 100 according to an embodiment of the present invention is described.

[0024] Combination Figures 1 to 3 According to an embodiment of the present invention, the rotor 100 includes a rotor core 110 and magnets 120. The rotor core 110 includes a plurality of rotor laminations 111 stacked along the axial direction. The rotor laminations 111 define a plurality of magnet slot groups 112. The plurality of magnet slot groups 112 can be arranged sequentially in the circumferential direction of the rotor core 110. Each magnet slot group 112 defines a magnetic pole 113. Each magnet slot group 112 has a plurality of magnet slots 1121. Magnets 120 are disposed in the magnet slots 1121, and the magnetization directions of the magnets 120 disposed in adjacent magnet slot groups 112 are opposite, so that the polarity directions of adjacent magnetic poles 113 are opposite.

[0025] The magnetic steel trough assembly 112 includes at least two layers of magnetic steel troughs 1121 arranged radially. Each layer of magnetic steel troughs 1121 is symmetrically arranged relative to the center line of the magnetic poles 113. The line connecting each layer of magnetic steel troughs 1121 defines a reference circle. That is, each layer of magnetic steel troughs 1121 is arranged in an arc shape so that the magnets 120 set in each layer of magnetic steel troughs 1121 are arranged in an arc shape. The magnetic fields formed by the magnets 120 can be superimposed to improve the magnetization effect.

[0026] The centers of multiple reference circles are all located on the extension line of the center line of the magnetic pole 113. For example, multiple reference circles can be set concentrically. The distance between the axis of the rotor core 110 and the center of the reference circle is D1, and the outer diameter of the rotor core 110 is D2, where D1≥D2. This improves the magnetic concentration effect and allows the magnetic field to be concentrated on the air gap side and the stator side, which is beneficial to improve the sinusoidal nature of the air gap magnetic field, reduce harmonic interference, and thus help reduce the torque pulsation of the motor and improve the operating stability of the motor.

[0027] It should be noted that "air gap" refers to the gap between the inner circle of the motor stator and the outer circle of the rotor 100.

[0028] In related technologies, an unreasonable arrangement of magnets results in poor magnetization and an inability to concentrate them on the air gap and stator sides, which can easily lead to large torque pulsation in the motor and affect the motor's operational stability.

[0029] This application defines a reference circle by connecting the lines of each layer of magnet slots 1121, so that each layer of magnets 120 can be arranged in an arc shape, thereby allowing the magnetic fields formed by the magnets 120 to superimpose and improve the magnetization effect. Furthermore, by ensuring that the centers of multiple reference circles are all located on the extension line of the center line of the magnetic pole 113, and that the distance between the axis of the rotor core 110 and the center of the reference circle is greater than or equal to the outer diameter of the rotor core 110, the effect of magnetic field concentration on the air gap side and the stator side is improved, which is beneficial to improving the sinusoidal nature of the air gap magnetic field, thereby reducing harmonic interference, effectively reducing the torque pulsation of the motor, and improving the operating stability of the motor.

[0030] In some specific examples, rotor lamination 111 is made of silicon steel sheet.

[0031] In some specific embodiments of the invention, the rotor 100 is provided with six magnetic poles 113 arranged sequentially along its circumferential direction.

[0032] Reference Figure 2 In some embodiments of the present invention, the radial dimensions of the magnets 120 in the multiple magnet slots 1121 in the same layer are consistent. Specifically, the line connecting the multiple magnet slots 1121 in the same layer defines a reference circle, and the magnets 120 in the multiple magnet slots 1121 in the same layer have the same dimensions in the radial direction of the reference circle, so as to improve the symmetry of the magnetic field formed by each layer of magnets 120.

[0033] like Figure 2 As shown, in some embodiments of the present invention, the length edge of each magnet groove 1121 is tangent to or coincides with the reference circle.

[0034] For example, each magnet groove 1121 can be formed as a groove structure with a generally rectangular outer contour. The edge of each magnet groove 1121 in the radial direction of the reference circle is its length edge, and its length edge can extend in an arc shape so that the length edge of each magnet groove 1121 can coincide with the reference circle; or, the length edge of each magnet groove 1121 can extend in a straight line and be tangent to the reference circle, and the tangency point can be located on the length edge of the magnet groove 1121.

[0035] The above technical solution is beneficial to ensure that the magnetic steel slots 1121 of each layer are evenly arranged along the reference circle, which helps to prevent uneven magnetic field distribution caused by deviation of the magnetic steel slots 1121, and also helps to improve the uniformity of mass distribution of the rotor core 110, thereby ensuring the uniformity of force on the rotor 100 when the motor is running.

[0036] Combination Figure 1 and Figure 3In some embodiments of the present invention, each magnet slot 1121 includes a first slot segment 11211 and a second slot segment 11212, and each magnet 120 includes a first magnet segment 121 and a second magnet segment 122. The first magnet segment 121 is disposed in the first slot segment 11211, and the second magnet segment 122 is disposed in the second slot segment 11212. By dividing the magnet slot 1121 into the first slot segment 11211 and the second slot segment 11212, and correspondingly dividing each magnet 120 into the first magnet segment 121 and the second magnet segment 122, it is beneficial to improve the convenience of positioning and assembling the magnet 120 with the magnet slot 1121, and to facilitate the uniform arrangement of multiple magnets 120 into an arc structure with the curvature center located on the center line of the magnetic pole 113 and located on the air gap side. This is beneficial to improve the sinusoidality of the magnetic field on the air gap side, reduce torque pulsation, and also beneficial to improve the fundamental amplitude of the air gap magnetic flux density and improve the utilization rate of the magnet 120.

[0037] Combination Figure 1 and Figure 3 In some embodiments of the present invention, a partition rib 140 is provided between the first groove segment 11211 and the second groove segment 11212.

[0038] For example, the partition rib 140 is supported between the two side walls of the magnet groove 1121 arranged opposite each other in the radial direction of the reference circle. It can also be understood that the partition rib 140 is supported between the two length edges of the magnet groove 1121 and can divide the magnet groove 1121 into a first groove segment 11211 and a second groove segment 11212 that are spaced apart. The first magnet segment 121 and the second magnet segment 122 are respectively arranged between the first groove segment 11211 and the second groove segment 11212. The partition rib 140 can separate the first magnet segment 121 and the second magnet segment 122.

[0039] In the above technical solution, by setting a partition rib 140 in the magnet groove 1121, the magnet groove 1121 is divided into a first groove segment 11211 and a recessed groove segment. The partition rib 140 can support the magnet groove 1121, which is beneficial for dispersing stress and reducing the risk of deformation of the magnet groove 1121. Magnetic flux can flow through the partition rib 140 between the first magnet segment 121 and the second magnet segment 122, which is beneficial for reducing the equivalent magnetic reluctance of the d-axis.

[0040] Combination Figure 1 and Figure 3In some embodiments of the present invention, the rotor lamination 111 is provided with magnetic barrier grooves, which include: a first magnetic barrier groove 151 located on at least one side edge of the width of each magnet slot 1121, the first magnetic barrier groove 151 communicating with the magnet slot 1121. The magnetic barrier groove also includes: a second magnetic barrier groove 152 located on the side edge of the outermost magnet slot 1121 in the layer of magnet slots 1121 adjacent to the axis, on the side away from the center line of the magnetic pole 113, the second magnetic barrier groove 152 communicating with the magnet slot 1121. The magnetic barrier groove also includes: a third magnetic barrier groove 153 located radially outside the second magnetic barrier groove 152.

[0041] For ease of description, we will take as an example that each magnet slot group 112 includes three layers of magnet slots 1121 arranged radially in sequence. The magnet slot 1121 closest to the axis is defined as the first layer of magnet slots, and the other two layers of magnet slots 1121 arranged outward from the axis of rotor 100 are the second layer of magnet slots and the third layer of magnet slots, respectively.

[0042] Each of the second and third layer magnetic steel slots 1121 has a first magnetic barrier slot 151 on both sides of its width. The two outermost magnetic steel slots 1121 in the first layer have a second magnetic barrier slot 152 on the side of their width away from the center line of the magnetic pole 113, and a first magnetic barrier slot 151 on the side of their width closer to the center line of the magnetic pole 113. The remaining magnetic steel slots 1121 in the first layer also have first magnetic barrier slots 151 on both sides of their width. In the radial direction parallel to the rotor 100, a third magnetic barrier slot 153 is located radially outside the second magnetic barrier slot 152. The first, second, and third magnetic barrier slots 151, 152, and 153 are all filled with air to form an air magnetic barrier, thereby restricting the magnetic flux path.

[0043] By combining the above technical solutions, the rotor 100 can achieve variable leakage flux characteristics and anti-salient pole characteristics. The principle of achieving the corresponding characteristics is briefly described below based on the above technical solutions.

[0044] Specifically, rotor leakage flux refers to the magnetic flux that originates from magnet 120, passes through rotor core 110, and returns directly to magnet 120 without passing through the air gap. Rotor leakage flux includes inter-pole leakage flux and intra-pole leakage flux. Inter-pole leakage flux is the permanent magnet flux that originates from magnet 120 and flows to the adjacent magnet 120 of pole 113, with the leakage flux path including a pair of adjacent poles 113. Intra-pole leakage flux is the permanent magnet flux that originates from magnet 120 and returns to the magnet 120 within that pole 113, with the leakage flux path including the magnet 120 within one pole 113. Variable leakage flux refers to subjecting the leakage flux to the motor load, i.e., the q-axis current (i...). q Size control. Due to i qThe resulting magnetic field interacts with the permanent magnet magnetic field near the neutral line (i.e., the q-axis, or the intersection axis) of the two magnetic poles 113, therefore i q Only the leakage flux near the q-axis can be controlled; the leakage flux within the poles is not affected by i. q Control, therefore, in order to ensure i q To effectively control leakage flux, it is necessary to prevent the generation of leakage flux within the poles.

[0045] For ease of description, we will take as an example that each magnet slot group 112 includes three layers of magnet slots 1121 arranged radially in sequence. The magnet slot 1121 closest to the axis in the three layers of magnet slots 1121 is defined as the first layer of magnet slots, and the magnet 120 set in the first layer of magnet slots is defined as the first layer of magnet 120. The other two layers of magnet slots 1121 arranged outward from the axis of rotor 100 are the second layer of magnet slots and the third layer of magnet slots, respectively. The magnet 120 set in the second layer of magnet slots and the third layer of magnet slots are defined as the second layer of magnet 120 and the third layer of magnet 120, respectively.

[0046] Electromagnetic field simulation analysis of the rotor 100 of this application revealed that intra-pole magnetic leakage mainly occurs on the side of the first layer of magnets 120 away from the center line of the magnetic pole 113. By setting second magnetic barrier slots 152 along the width edge of the two outermost magnet slots 1121 in the first layer of magnet slots away from the center line of the magnetic pole 113, the path of intra-pole magnetic leakage is blocked, allowing the leakage flux to flow to the other magnetic pole 113, thereby effectively reducing the generation of intra-pole magnetic leakage and ensuring i q The effect of controlling leakage flux.

[0047] Furthermore, in the radial direction parallel to the rotor 100, a third magnetic barrier groove 153 is provided on the radial outer side of the second magnetic barrier groove 152. The third magnetic barrier groove 153 is located on the q-axis. The third magnetic barrier groove 153 and the second magnetic barrier groove 152 can cooperate to jointly define an inner magnetic leakage path. At the same time, a magnetic leakage path is also formed on the radial outer side of the third magnetic barrier groove 153.

[0048] When the motor is under light load, i q The leakage flux is relatively small, and the saturation degree of the leakage flux path is low. The leakage flux passes through the leakage flux path radially outside the third magnetic barrier slot 153 and the leakage flux path before the second magnetic barrier slot 152 and the third magnetic barrier slot 153, respectively, to divert the air gap flux and achieve the effect of light-load weak magnetization. This is beneficial to reduce the loss of the rotor core 110 while maintaining sufficient output torque, thereby improving light-load efficiency. As the motor load increases, i qAs the magnetic flux increases, the leakage flux path gradually saturates, its magnetic permeability gradually decreases, and the magnetic resistance increases, thereby gradually reducing the leakage flux and weakening the shunting effect on the air gap flux. When the leakage flux path is completely saturated, the leakage flux disappears, improving the effect of the permanent magnet flux passing through the air gap, achieving heavy-load magnetization, and improving the torque output capability of the motor under heavy load.

[0049] Thus, the variable leakage magnetic field characteristic of the rotor 100 of this application is achieved.

[0050] Regarding anti-salient pole characteristics: According to the torque equation of a three-phase permanent magnet synchronous motor: T e =(3 / 2) p [ψ f i q +(L d L q ) i d i q ), where the permanent magnet torque T emp =(3 / 2) p ψ f i q Reluctance torque T eIr =(3 / 2) p (L d L q ) i d i q p is the extreme logarithm, ψ f For permanent magnet flux linkage, i q Let i be the q-axis current. d Let L be the d-axis current. d For the d-axis inductance, L q It is the q-axis inductance.

[0051] According to the above torque equation, considering that the rotor 100 has magnetic barrier slots, which increase the magnetic resistance of the air, and thus increase the magnetic resistance of the q-axis, L q The decrease in d-axis inductance leads to a decrease in the difference between d-axis and q-axis inductance, resulting in a decrease in reluctance torque and thus a decrease in motor torque. Therefore, it is necessary to increase the difference between d-axis and q-axis inductance to increase reluctance torque and thereby increase motor torque.

[0052] Therefore, it is necessary to make L d >L q So in order to reduce L qTo increase the q-axis magnetic reluctance, a first magnetic barrier slot 151 is added to the existing second and third magnetic barrier slots 152 and 153. This blocks the q-axis magnetic circuit between two adjacent layers of magnets 120, thereby increasing the q-axis magnetic reluctance. The increase in q-axis magnetic reluctance reduces the q-axis permeability. Since the q-axis inductance is directly proportional to the q-axis permeability, this allows for the realization of L... q The decrease; in order to increase L d To reduce the d-axis magnetic reluctance, a partition rib 140 is installed within the magnet slot 1121. This allows magnetic flux to flow between the first magnet segment 121 and the second magnet segment 122 through the partition rib 140, thereby reducing the d-axis magnetic reluctance and increasing the d-axis permeability, thus improving the L... d The corresponding increase, thereby increasing the difference between the d-axis inductance and the q-axis inductance, achieves the anti-salient pole characteristic of the motor. When the reluctance torque is positive, i d >0, the motor is in a magnetizing state to fully utilize the reluctance torque; and when the motor is under low speed and heavy load, magnetizing can effectively increase the torque. Combined with the characteristics of variable leakage flux and heavy-load magnetization, this facilitates the output of high torque at low speeds. Throughout the entire speed range, as the speed increases, the motor gradually transitions from magnetizing to magnetizing, due to L... d Larger, i required at the same field weakening depth d Smaller and with better weak magnetic properties.

[0053] According to the voltage equation of a three-phase permanent magnet synchronous motor: In this equation, (L d i d +ψ f The back electromotive force ω is the core adjustment term for field weakening speed enhancement. As the motor speed increases, the back electromotive force ω of the motor increases. ψ f To increase it, a larger and negative value of i is required. d To cancel it out, we can conclude that L d The larger the number, the same i d The better the effect of weakening the magnetic field.

[0054] too large i d This is the cause of the irreversible demagnetization of magnet 120, and when the motor is below the reference speed... d A positive value indicates magnetization; when entering a weak magnetic field, due to L... d Big, needs i dSmaller size effectively reduces the risk of demagnetization, thus ensuring that the risk of demagnetization is reduced even when the magnet 120 is thinner. Because the risk of demagnetization of the magnet 120 is reduced, the motor can continuously apply field weakening control (even maintaining field weakening at higher speeds) to break through the speed limit and widen the speed range. When the motor speed range is widened, the motor can not only reach higher speeds, but also output effective torque more stably in the high-speed range without being forced to limit field weakening due to the risk of demagnetization, which is conducive to improving the high-speed external characteristics.

[0055] In a further embodiment of the present invention, the magnetic reluctance of the magnet 120 can be reduced by further reducing the thickness of the magnet 120 (i.e., the radial dimension of the magnet 120), thereby facilitating a further reduction in the d-axis magnetic reluctance. The thickness of the magnet 120 in this application can be 0.5-0.6 times the thickness of magnets in related technologies.

[0056] In some embodiments of the present invention, the first magnetic barrier and the second magnetic barrier groove 152 extend in a direction perpendicular to the magnetic field lines, which is beneficial to improving the effect of blocking leakage magnetic flux within the pole, thereby improving the control effect of leakage magnetic flux on the light and heavy load of the motor.

[0057] Combination Figure 1 and Figure 3 In some embodiments of the present invention, the edges and corners of the first magnetic barrier groove 151, the second magnetic barrier groove 152, and the third magnetic barrier groove 153 are all constructed with rounded transitions to further prevent stress concentration and to improve the mechanical strength of the rotor lamination 111, and to enable the rotor 100 to withstand higher centrifugal forces, thereby facilitating the high-speed operation of the motor and improving the power density of the motor.

[0058] The motor according to an embodiment of the present invention includes the rotor 100 described above.

[0059] Since the motor includes the aforementioned rotor 100, a reference circle is defined by connecting the slots 1121 of each layer of magnets, so that each layer of magnets 120 can be arranged in an arc shape. This allows the magnetic fields formed by the magnets 120 to be superimposed, improving the magnetization effect. Furthermore, by ensuring that the centers of multiple reference circles are all located on the extension line of the center line of the magnetic poles 113, and that the distance between the axis of the rotor core 110 and the center of the reference circle is greater than or equal to the outer diameter of the rotor core 110, the effect of magnetic field concentration on the air gap side and the stator side is improved. This is beneficial to improving the sinusoidal nature of the air gap magnetic field, thereby reducing harmonic interference, effectively reducing motor torque pulsation, and improving motor operating stability.

[0060] In some specific embodiments, the motor is a built-in permanent magnet synchronous motor.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "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 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.

[0062] Although embodiments of the 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 invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor characterized by, The rotor core (110) comprises a plurality of rotor laminations (111) stacked in the axial direction, the rotor laminations (111) defining a plurality of magnetic steel slot groups (112), each of the magnetic steel slot groups (112) defining a magnetic pole (113), each of the magnetic steel slot groups (112) having a plurality of magnetic steel slots (1121); The magnetic steel (120) is arranged in the magnetic steel slot (1121); Wherein The magnetic steel slot group (112) comprises: at least two layers of the magnetic steel slots (1121) arranged in the radial direction in sequence, each layer of the magnetic steel slots (1121) is arranged symmetrically relative to the center line of the magnetic pole (113), the connecting line of each layer of the magnetic steel slots (1121) defines a reference circle, the centers of a plurality of the reference circles are located on the extension line of the center line of the magnetic pole (113), the distance between the center of the reference circle and the axis of the rotor core (110) is D1, the outer diameter of the rotor core (110) is D2, and D1≥D2. The radial dimensions of the magnetic steel (120) in the plurality of magnetic steel slots (1121) of the same layer are consistent.

2. The rotor of claim 1, wherein The length side of each of the magnetic steel slots (1121) is tangent to or coincides with the reference circle.

3. The rotor of claim 2, wherein Each of the magnetic steel slots (1121) comprises: a first slot section (11211) and a second slot section (11212), each of the magnetic steels (120) comprises: a first magnetic steel section (121) and a second magnetic steel section (122), the first magnetic steel section (121) is arranged in the first slot section (11211), and the second magnetic steel section (122) is arranged in the second slot section (11212).

4. The rotor of claim 1, wherein A partition rib (140) is arranged between the first slot section (11211) and the second slot section (11212).

5. The rotor of claim 4, wherein A magnetic barrier groove is formed on the rotor lamination (111), the magnetic barrier groove comprises: a first magnetic barrier groove (151) located on at least one side of the width of each of the magnetic steel slots (1121), and the first magnetic barrier groove (151) is in communication with the magnetic steel slot (1121).

6. The rotor of claim 1, wherein The magnetic barrier groove further comprises: a second magnetic barrier groove (152) formed on the width side away from the center line of the magnetic pole (113) of the outermost magnetic steel slot (1121) in one of the magnetic steel slots (1121) adjacent to the axis in the plurality of layers of the magnetic steel slots (1121), and the second magnetic barrier groove (152) is in communication with the magnetic steel slot (1121).

7. The rotor of claim 6, wherein The magnetic barrier groove further comprises: a third magnetic barrier groove (153) located radially outside the second magnetic barrier groove (152).

8. The rotor of claim 7, wherein The edge corner regions of the first magnetic barrier groove (151), the second magnetic barrier groove (152), and the third magnetic barrier groove (153) are configured as circular arc transitions.

9. The rotor of claim 8, wherein The rotor according to any one of claims 1-9.

10. An electric machine characterized by The rotor according to any one of claims 1-9. ​

Images