Rotor lamination, rotor, electric machine, powertrain and vehicle

Abstract

The application discloses a rotor lamination, a rotor, a motor, a power assembly and a vehicle, relates to the technical field of driving motors, and aims to solve the problem of how to improve the NVH performance of a motor. The rotor lamination comprises a lamination body and a plurality of magnetic steel mounting portions. The plurality of magnetic steel mounting portions are arranged on the lamination body and along the circumference of the lamination body. The magnetic steel mounting portion comprises a first group of magnetic steel grooves and a second group of magnetic steel grooves. The second group of magnetic steel grooves is located on the side, away from the center of the lamination body, of the first group of magnetic steel grooves. The first group of magnetic steel grooves comprises a first magnetic steel groove and a second magnetic steel groove. The number of the first magnetic steel grooves is two, and the first magnetic steel grooves are arranged at intervals along the circumference; the second magnetic steel groove is arranged between the two first magnetic steel grooves. The second group of magnetic steel grooves comprises a third magnetic steel groove and a fourth magnetic steel groove. The number of the third magnetic steel grooves is two, and the third magnetic steel grooves are arranged at intervals along the circumference; the fourth magnetic steel groove is arranged between the two third magnetic steel grooves. The rotor lamination is used for a rotor of a motor.

Description

Technical Field

[0001] This application relates to the field of drive motor technology, and in particular to a rotor lamination, rotor, motor, powertrain, and vehicle. Background Technology

[0002] As people's living standards improve, cars have become the main means of transportation for everyday families. Meanwhile, with the continuous advancement of science and technology, new energy vehicles, with their advantages such as clean energy, are gradually becoming the primary choice for users. The electric motor is a major component of new energy vehicles, but existing motors suffer from high noise and vibration issues in their rotors, affecting the motor's NVH performance. Summary of the Invention

[0003] The purpose of this application is to provide a rotor lamination, rotor, motor, powertrain, and vehicle, which aims to solve the problem of how to improve the NVH performance of the motor.

[0004] In a first aspect, a rotor lamination is provided for use in the rotor of an electric motor, comprising a lamination body and a plurality of magnet mounting portions. The plurality of magnet mounting portions are disposed on the lamination body and arranged circumferentially along the lamination body. Each magnet mounting portion includes a first set of magnet slots and a second set of magnet slots. The second set of magnet slots is located on the side of the first set of magnet slots opposite to the center of the lamination body. The first set of magnet slots includes a first magnet slot and a second magnet slot. There are two first magnet slots spaced apart circumferentially, and a second magnet slot is disposed between the two first magnet slots. The second set of magnet slots includes a third magnet slot and a fourth magnet slot. There are two third magnet slots spaced apart circumferentially, and a fourth magnet slot is disposed between the two third magnet slots.

[0005] The rotor laminations provided in this application embodiment can form a double U-shaped structure through the first and second magnetic slots of the first group of magnetic slots, and the third and fourth magnetic slots of the second group of magnetic slots. This can effectively utilize the reluctance torque of the motor, reduce the phenomenon of magnetic leakage, thereby improving the rotor's limiting speed and power density, and improving the motor's NVH performance.

[0006] Optionally, the opening angle α1 of the first set of magnet slots satisfies: 2.1×α01≤α1≤2.5×α01. The second set of magnet slots is located on the side opposite to the center of the punch body of the first set of magnet slots, and the opening angle α2 of the second set of magnet slots satisfies: 5.5×α02≤α2≤5.9×α02. Wherein, α01 is the polar arc angle of the first set of magnet slots, and α02 is the polar arc angle of the second set of magnet slots.

[0007] Optionally, the two first magnet slots extend from one end to the other, toward the center of the lamination body, and tilt in the direction of proximity when writing. The included angle between the two first magnet slots forms an angle α1.

[0008] Optionally, at least one second magnet slot is located between the two first magnet slots at one end facing the center of the lamination body.

[0009] Optionally, there may be multiple second magnet slots. Multiple second magnet slots are arranged sequentially along the arrangement direction of the two first magnet slots towards the center of the lamination body.

[0010] Optionally, the two third magnet grooves extend from one end to the other, toward the center of the lamination body, and are inclined toward each other. The included angle between the two third magnet grooves forms an angle α2.

[0011] Optionally, at least one fourth magnet slot is located between the two third magnet slots at one end facing the center of the lamination body.

[0012] Optionally, a first reinforcing rib is formed in the portion of the lamination body located between the first magnet slot and two adjacent second magnet slots. A second reinforcing rib is formed in the portion of the lamination body located between two adjacent second magnet slots. A third reinforcing rib is formed in the portion of the lamination body located between the third magnet slot and an adjacent fourth magnet slot. Along the circumferential direction of the lamination body, the first and second reinforcing ribs, as well as the second and third reinforcing ribs, are staggered.

[0013] Optionally, the portion of the lamination body located between the first magnet slot and the adjacent second magnet slot forms a first reinforcing rib. The portion of the lamination body located between two adjacent second magnet slots forms a second reinforcing rib. Along the extension direction of the first convex trajectory line, the dimension of the first reinforcing rib is a1, and the dimension of the second reinforcing rib is a2, where a1 and a2 satisfy: 1.2mm≤a1≤1.8mm, 1.2mm≤a2≤1.8mm.

[0014] Optionally, a1 and a2 also satisfy: 3.7mm≤a1+a2×2≤4.8mm.

[0015] Optionally, the dimension of the first reinforcing rib along the arrangement direction perpendicular to the first magnet slot and the adjacent second magnet slot is K1, and the dimension of the second reinforcing rib along the arrangement direction of the two adjacent second magnet slots is K2. K1 and a1 satisfy: 4.8≤K1 / a1≤10.2, and / or, K2 and a2 satisfy: 4.8≤K2 / a2≤10.2.

[0016] Optionally, a third reinforcing rib is formed in the portion of the lamination body located between the third magnet slot and the adjacent fourth magnet slot. The dimension of the third reinforcing rib is a3 along the arrangement direction of the third magnet slot and the adjacent fourth magnet slot. The dimension of the third reinforcing rib along the direction perpendicular to the arrangement direction of the third magnet slot and the adjacent fourth magnet slot is K3. a3 and K3 satisfy: 5.2 ≤ K3 / a3 ≤ 7.4.

[0017] Optionally, the dimension L1 of the first magnet groove in the extension direction satisfies: 7.2mm ≤ L1 ≤ 9.1mm. The dimension L2 of the second magnet groove in the extension direction satisfies: 16.5mm ≤ L2 ≤ 18.4mm.

[0018] Optionally, the dimension W1 of the first magnet groove perpendicular to the extension direction satisfies: 7mm ≤ W1 ≤ 7.6mm. The dimension W2 of the second magnet groove perpendicular to the extension direction satisfies: 7mm ≤ W2 ≤ 7.6mm.

[0019] Optionally, the lamination body is provided with mounting holes. Multiple magnet mounting portions are located around the mounting holes and arranged along the axial direction of the mounting holes. The distance from the first set of magnet slots to the mounting holes is d1, and the distance from the outer edge of the lamination body to the mounting holes is the second distance d2. d1 and d2 satisfy: 0.4≤d1 / d2≤0.61.

[0020] Optionally, the included angle region between the two first magnet slots is designated as the first region. The lamination body also has a first stress relief hole, which is located on the side of the first magnet slot opposite to the first region.

[0021] Optionally, the distance from the geometric center of the first stress relief hole to the center of the lamination body is R2. The lamination body is circular, and its radius is R1. R1 and R2 satisfy: 0.55≤R2 / R1≤0.65. The two first magnet slots are symmetrically arranged about a first axis passing through the center of the lamination body. The line connecting the geometric center of the first stress relief hole and the center of the lamination body is a second axis, and the angle θ1 between the second axis and the first axis satisfies: 9°≤θ1≤13°.

[0022] Optionally, the lamination body is also provided with a second stress relief hole, which is located on the side of the first stress relief hole opposite to the first magnet groove.

[0023] Optionally, the distance from the geometric center of the second stress relief hole to the center of the lamination body is R3. The lamination body is circular with a radius of R1, and R1 and R3 satisfy: 0.55≤R3 / R1≤0.65. The two first magnet slots are symmetrically arranged about a first axis passing through the center of the lamination body. The line connecting the geometric center of the second stress relief hole and the center of the lamination body is a third axis, and the angle θ2 between the third axis and the first axis satisfies: 180° / P-10°≤θ2≤180° / P.

[0024] Optionally, the included angle region between the two third magnet slots is a second included angle region, and at least one third stress relief hole is provided in the second included angle region.

[0025] Optionally, the portion of the lamination body located between the two third magnet slots forms a fourth reinforcing rib. At least a portion of the third stress relief hole is opposite the fourth reinforcing rib along the radial direction of the lamination body.

[0026] Alternatively, the fourth magnet groove is located between the two third magnet grooves at one end facing the center of the lamination body, and at least a portion of the third stress relief hole is opposite to the fourth magnet groove along the radial direction of the lamination body.

[0027] Optionally, the two first magnet slots are symmetrically arranged about a first axis passing through the center of the lamination body, and the number of third stress relief holes is two. The two third stress relief holes are located on opposite sides of the first axis and are symmetrically arranged about the first axis.

[0028] Optionally, the spacing between the two third stress relief holes is d3, and the distance from the geometric center of the third stress relief hole to the outer edge of the lamination body is d4; d3 and d4 satisfy: 2.5≤d4 / d3≤4.

[0029] Optionally, the circumferential dimension of the third stress relief hole along the body of the lamination is L3, and the radial dimension of the third stress relief hole along the body of the lamination is W3; L3 and W3 satisfy: 1.4≤L3 / W3≤1.8.

[0030] Optionally, the distance d5 from the third stress relief hole to the outer edge of the lamination body satisfies: 0.9mm≤d5≤1.3mm.

[0031] Optionally, the lamination body is also provided with a stress relief groove. Along the circumference of the lamination body, the stress relief groove is located between two adjacent magnet mounting parts, and the stress relief groove passes through the outer edge of the lamination body.

[0032] Optionally, the lamination body is also provided with a fourth stress relief hole; along the circumference of the lamination body, the fourth stress relief hole is located between two adjacent magnet mounting parts, and the fourth stress relief hole is circumferentially closed; the two first magnet grooves are symmetrically arranged about the first axis passing through the center of the lamination body; the fourth stress relief hole passes through the fourth axis, the fourth axis passes through the center of the lamination body, and the included angle θ4 between the fourth axis and the first axis satisfies: θ4=180° / P.

[0033] Optionally, the lamination body is provided with mounting holes, and multiple magnet mounting parts are located around the mounting holes and arranged circumferentially along the mounting holes; along the extension direction of the first axis, the fourth stress relief hole is located between the second magnet groove and the mounting hole; along the extension direction of the first axis, the distance between the fourth stress relief hole and the second magnet groove is m1, the size of the fourth stress relief hole is m2, and the distance between the fourth stress relief hole and the mounting hole is m3; m1, m2 and m3 satisfy: m1:m2:m3=(3-3.5):(5-6):(7-8).

[0034] Optionally, the portion of the fourth stress relief hole located between the fourth axis and the first axis includes a first inner wall and a second inner wall. The first inner wall and the second inner wall are arranged radially along the body of the lamination, and the included angle θ5 between the first inner wall and the second inner wall satisfies: 65°≤θ5≤70°.

[0035] Optionally, at least one of the first and second sets of magnetic steel grooves has a groove recessed on its edge toward the side away from the magnetic steel groove, and the included angle θ6 between at least one inner edge of the groove and the inner edge of the adjacent magnetic steel groove satisfies: 5°≤θ6≤8°.

[0036] Secondly, a rotor is provided, comprising a first set of magnets, a second set of magnets, and rotor laminations as described in the first aspect. The first set of magnets is housed in slots of the first set of magnets. The second set of magnets is housed in slots of the second set of magnets.

[0037] Optionally, the magnets in the first group of magnets include multiple magnet units arranged axially along the rotor laminations. Alternatively, the magnets in the first group of magnets include multiple magnet units arranged along the extension direction of the magnet slots.

[0038] Optionally, the two first magnet slots extend from one end to the other toward the center of the lamination body and are inclined toward each other; at least one second magnet slot is located between the ends of the two first magnet slots that are toward the center of the lamination body; the magnets in the first magnet slots include a plurality of magnet units arranged along the extension direction of the first magnet slots, and the magnets in the second magnet slots include a plurality of magnet units arranged along the extension direction of the second magnet slots, and the arrangement density of the magnet units in the first magnet slots is greater than the arrangement density of the magnet units in the second magnet slots.

[0039] Optionally, the magnets in each magnet slot of the second set may include multiple magnet units arranged along the extension direction of the magnet slot, or multiple magnet units arranged along the axial direction of the rotor lamination.

[0040] Optionally, the second set of magnet slots includes two third magnet slots and at least one fourth magnet slot; the two third magnet slots extend from one end to the other toward the center of the lamination body and are inclined toward each other; the at least one fourth magnet slot is located between the ends of the two third magnet slots that are toward the center of the lamination body; the magnets in the third magnet slots include a plurality of magnet units arranged along the extension direction of the third magnet slots, and the magnets in the fourth magnet slots include a plurality of magnet units arranged along the extension direction of the fourth magnet slots, and the arrangement density of the magnet units in the third magnet slots is greater than the arrangement density of the magnet units in the fourth magnet slots.

[0041] Thirdly, an electric motor is provided, including a stator and any of the rotors described in the second aspect.

[0042] Optionally, the no-load air gap magnetic flux density of the motor is greater than 0.7T and less than or equal to 0.9T. Alternatively, the no-load air gap magnetic flux density of the motor is greater than 0.75T and less than or equal to 0.85T. Alternatively, the no-load air gap magnetic flux density of the motor is greater than 0.78T and less than or equal to 0.82T.

[0043] Optionally, there may be multiple stators. The multiple stators are arranged in a row. At least one rotor is provided between two adjacent stators, and the extension direction of the shaft of the at least one rotor is consistent with the arrangement direction of the multiple stators.

[0044] Optionally, there may be multiple rotors. Multiple rotors are coaxially arranged and aligned along the extension direction of the shaft. At least one stator is provided between any two adjacent rotors.

[0045] Optionally, each pole and each phase slot of the motor is an integer greater than or equal to 1.

[0046] Fourthly, a powertrain is provided, including any one of the electric motors in the third aspect.

[0047] Optionally, the powertrain also includes a transmission. The electric motor is connected to the transmission via a shaft.

[0048] Fifthly, a vehicle is provided, comprising any one of the electric motors in the third aspect or any one of the powertrains in the fourth aspect. Attached Figure Description

[0049] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a schematic diagram of the structure of a rotor lamination provided in an embodiment of this application;

[0051] Figure 2 A schematic diagram of a rotor lamination with span markings;

[0052] Figure 3 for Figure 1 One of the schematic diagrams of a portion of the rotor lamination structure shown;

[0053] Figure 4 for Figure 1 The second schematic diagram shows a partial structure of the rotor lamination;

[0054] Figure 5 This is one of the simulation diagrams of the demagnetization region provided in the embodiments of this application;

[0055] Figure 6 This is the second simulation diagram of the demagnetization region provided in the embodiments of this application;

[0056] Figure 7 This is the third simulation diagram of the demagnetization region provided in the embodiments of this application;

[0057] Figure 8 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0058] Figure 9 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0059] Figure 10 This is a graph showing the maximum power as a function of thickness.

[0060] Figure 11 This is a graph showing the stress limit as a function of thickness.

[0061] Figure 12 This is a graph showing the variation of magnetic flux leakage coefficient with thickness.

[0062] Figure 13 This is a graph showing the power density as a function of magnet area;

[0063] Figure 14 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0064] Figure 15 This is a schematic diagram of another rotor lamination provided in an embodiment of this application;

[0065] Figure 16 This is a diagram showing the stress variation of d1 / d2 and the stiffener.

[0066] Figure 17 The stress distribution diagram is shown when the rotor yoke ratio d1 / d2 is 0.46.

[0067] Figure 18 The stress distribution diagram is shown when the rotor yoke ratio d1 / d2 is 0.4.

[0068] Figure 19 This is a partial structural schematic diagram of a rotor lamination provided in an embodiment of this application;

[0069] Figure 20 The stress diagram is shown when K1 / a1 is less than 4.8 at the limiting speed.

[0070] Figure 21 The stress diagram is shown when K2 / a2 is greater than 7.4 at the limiting speed.

[0071] Figure 22 Stress diagram of rotor lamination provided in the embodiments of this application;

[0072] Figure 23 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0073] Figure 24 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0074] Figure 25 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0075] Figure 26 Stress diagram for cases without stress relief holes;

[0076] Figure 27 Stress diagram with stress relief holes;

[0077] Figure 28 A stress diagram with a third stress relief hole provided for an embodiment of this application;

[0078] Figure 29 A stress diagram with a second stress relief hole provided for an embodiment of this application;

[0079] Figure 30 A stress diagram provided for embodiments of this application, which simultaneously includes a second stress relief hole and a third stress relief hole;

[0080] Figure 31 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0081] Figure 32 This is a schematic diagram of another rotor lamination provided in an embodiment of this application;

[0082] Figure 33 This is a schematic diagram of another rotor lamination provided in an embodiment of this application;

[0083] Figure 34 A schematic diagram of a 6-pole double-V rotor lamination structure provided in an embodiment of this application;

[0084] Figure 35 This is one of the stress distribution diagrams of the stator lamination provided in the embodiments of this application;

[0085] Figure 36 The second stress distribution diagram of the stator lamination provided in the embodiments of this application;

[0086] Figure 37 This is the third stress distribution diagram of the stator lamination provided in the embodiments of this application;

[0087] Figure 38 This is one of the deformation contour maps of the stator lamination provided in the embodiments of this application;

[0088] Figure 39 This is the second deformation contour map of the stator lamination provided in the embodiments of this application;

[0089] Figure 40 The third deformation contour map of the stator lamination provided in the embodiments of this application;

[0090] Figure 41 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0091] Figure 42 The stress diagram is for a static state.

[0092] Figure 43 Stress diagram at high speed;

[0093] Figure 44 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application;

[0094] Figure 45 A schematic diagram of a magnet provided in an embodiment of this application;

[0095] Figure 46 The magnetic force distribution diagram of a given three-phase winding subjected to an alternating current of Id;

[0096] Figure 47 The magnetic force distribution diagram of a given three-phase winding subjected to an alternating current of Id = Iq;

[0097] Figure 48 The magnetic force distribution diagram of a given three-phase winding subjected to an alternating current of Iq;

[0098] Figure 49 The eddy current loss contour plot is divided into two segments radially near the d-axis and two segments radially near the q-axis.

[0099] Figure 50 The eddy current loss cloud diagram is divided into two segments radially near the d-axis and four segments radially near the q-axis.

[0100] Figure 51 The figure shows the simulation results of eddy current loss. Detailed Implementation

[0101] In the embodiments of this application, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of that feature.

[0102] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0103] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0104] In the embodiments of this application, "parallel," "perpendicular," and "equal" include the described situation and situations similar to the described situation, the range of which is within an acceptable deviation range, said acceptable deviation range being determined by those skilled in the art taking into account the measurement under discussion and the error associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range for approximate parallelism may be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range for approximate perpendicularity may also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range for approximate equality may be, for example, a difference between the two equals being less than or equal to 5% of either one.

[0105] This application provides an electric motor. This motor can be applied to the powertrain of a vehicle. The vehicle includes, but is not limited to, pure electric vehicles, hybrid electric vehicles, range-extended electric vehicles, and plug-in hybrid electric vehicles, and may also include, but is not limited to, centralized drive vehicles, four-wheel drive vehicles, two-wheel drive vehicles, and wheel-side drive vehicles.

[0106] Of course, in other embodiments, the motor provided in this application can also be applied to other mechanical equipment, such as engineering machinery and production machinery. This application does not specifically limit the application field of the motor. Moreover, the motor provided in this application can be used as both a drive motor and a generator motor.

[0107] The motor can be a low-speed motor, a medium-speed motor, a high-speed motor, or an ultra-high-speed motor with a speed of 20,000 rpm or higher. This application uses an ultra-high-speed motor as an example, for instance, the motor speed can reach 30,000 rpm, which should not be considered a special limitation on the motor's configuration. The motor can be a three-phase motor or a five-phase motor; this application uses a three-phase motor as an example. Specifically, the three phases of the motor can include the U phase, V phase, and W phase. The motor can be a permanent magnet synchronous motor; of course, the motor can also be other types of motors, and this application does not specifically limit them.

[0108] An electric motor may include a stator and a rotor. The stator and rotor may be arranged along a direction perpendicular to the rotor's axis of rotation, thus making the motor a radial motor. Alternatively, in other embodiments, the stator and rotor may be arranged along the extension direction of the rotor's axis of rotation, thus making the motor an axial motor. The embodiments described below are further explanations based on the premise that the motor is a radial motor, and should not be considered as a specific limitation on the structural configuration of the motor.

[0109] The stator may include a stator core and a winding structure disposed on the stator core. The stator is used to cooperate with the rotor to drive the rotor to rotate about a rotation axis.

[0110] The structure of the rotor will be described in detail below.

[0111] In some embodiments, the rotor may include a rotor frame and a plurality of magnets disposed on the rotor frame. The rotor frame serves a supporting function. The rotor frame includes at least one rotor lamination, and when there are multiple rotor laminations, the multiple rotor laminations are stacked.

[0112] The rotor lamination includes a lamination body and multiple magnet mounting portions disposed on the lamination body. The multiple magnets are respectively mounted on these mounting portions to support and fix the magnets. The magnets can be permanent magnets. The multiple magnets are used to cooperate with the stator winding structure to drive the rotor to rotate relative to the stator.

[0113] The structure of the rotor laminations will be described in detail below.

[0114] like Figure 1 As shown, Figure 1This is a schematic diagram of a rotor lamination structure provided in an embodiment of this application. The rotor lamination 100 provided in this embodiment may include a lamination body 10 and a plurality of magnet mounting portions 20. The plurality of magnet mounting portions 20 are disposed on the lamination body 10 and arranged circumferentially along the lamination body 10. The number of magnet mounting portions 20 is equal to the number of poles of the motor. In some embodiments, the number of magnet mounting portions 20 is 6, suitable for a 6-pole motor. Of course, in other embodiments, the number of magnet mounting portions 20 may also be 4, 8, 12, 24, etc. This application uses a 6-pole motor as an example for illustration.

[0115] The magnet mounting section 20 includes a first set of magnet slots 21 arranged along a first convex trajectory line protruding toward the center of the lamination body 10, and a second set of magnet slots 22 arranged along a second convex trajectory line protruding toward the center of the lamination body 10. The first convex trajectory line and the second convex trajectory line can be U-shaped, V-shaped, or of course other shapes, and this application does not specifically limit them.

[0116] It should be noted that the magnet groove described in this embodiment refers to the portion of the receiving groove provided on the lamination body 10 that is actually used to receive the magnet. The shape and size of this groove are adapted to the shape and size of the magnet 50. The magnet groove described in this embodiment does not include other grooves located around and connected to the magnet groove that serve to provide magnetic isolation.

[0117] To facilitate the description of the embodiments below, it is necessary to first introduce the two concepts of "magnetic bridge" and "reinforcing rib". "Magnetic bridge" refers to the portion of the stamped body 10 between the two ends of the first set of magnetic steel grooves 21 in the arrangement direction and the outer edge of the stamped body 10, and the portion of the stamped body 10 between the two ends of the second set of magnetic steel grooves 22 in the arrangement direction and the outer edge of the stamped body 10. "Reinforcing rib" refers to the portion of the stamped body 10 located between two adjacent magnetic steel grooves in the first set of magnetic steel grooves 21, and the portion of the stamped body 10 located between two adjacent magnetic steel grooves in the second set of magnetic steel grooves 22.

[0118] In the rotor of an ultra-high speed motor, the rotor is subjected to centrifugal force when it rotates. The magnetic bridge and reinforcing ribs of the rotor lamination 100 will be subjected to large stress concentration. Once the stress in these places exceeds the allowable stress strength of the material of the rotor lamination 100, the rotor lamination 100 will be at risk of fracture failure under this stress for a long time.

[0119] Research has shown that if the motor needs to reach the same maximum speed, the thickness of the reinforcing ribs between the first set of magnet slots 21 and the second set of magnet slots 22 will vary with the size of the opening angle α1 of the first set of magnet slots 21 and the opening angle α2 of the second set of magnet slots 22. (Refer to...) Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of a rotor lamination with span markings. Figure 3 for Figure 1 One of the schematic diagrams of a portion of the rotor laminations is shown. Specifically, the larger the angle α1 of the first set of magnet slots 21, the better. Figure 2 As shown, the first set of magnet slots 21 is symmetrical about the d-axis. The larger the values ​​of X1 and X2 on the right side of the first set of magnet slots 21, the larger the area enclosed by the first set of magnet slots 21 becomes, resulting in more magnets, greater reluctance torque, and thus increased power density. The topology composed of the first set of magnet slots 21 and the second set of magnet slots 22, even with a large yoke angle, not only ensures the amount of magnets used but also maintains the rotor yoke ratio, meeting strength requirements. Furthermore, the inventors have discovered that the yoke angle also affects the harmonic content of the air gap magnetic field to some extent.

[0120] like Figure 4 As shown, the second set of magnet slots 22 is located on the side of the first set of magnet slots 21 away from the center of the lamination body 10. The first set of magnet slots 21 includes a first magnet slot 211 and a second magnet slot 212. There are two first magnet slots 211, which are spaced apart circumferentially, and the second magnet slot 212 is disposed between the two first magnet slots 211.

[0121] The second set of magnetic steel grooves 22 includes a third magnetic steel groove 221 and a fourth magnetic steel groove 222. There are two third magnetic steel grooves 221, which are spaced apart along the circumference. The fourth magnetic steel groove 222 is located between the two third magnetic steel grooves.

[0122] Based on this, the rotor lamination 100 provided in this application embodiment can form a double U-shaped structure through the first magnetic slot 211 and the second magnetic slot 212 of the first group of magnetic slots 21, and the third magnetic slot 221 and the fourth magnetic slot 222 of the second group of magnetic slots 22. This can effectively utilize the reluctance torque of the motor, reduce the phenomenon of magnetic leakage, thereby improving the rotor's limiting speed and power density, and improving the motor's NVH performance.

[0123] In some embodiments, refer to Figure 3 The angle α1 of the first set of magnetic grooves 21 satisfies: 2.1×α01≤α1≤2.5×α01. The second set of magnetic grooves 22 is located on one side of the first set of magnetic grooves 21, opposite to the center of the punch body 10, and the angle α2 of the second set of magnetic grooves 22 satisfies: 5.5×α02≤α2≤5.9×α02. The angle is the included angle formed by the magnetic grooves.

[0124] Wherein, α01 is the pole arc angle of the first group of magnet slots 21, and α02 is the pole arc angle of the second group of magnet slots 22. The pole arc angle is the angle of the central angle corresponding to the magnet slot.

[0125] Optionally, the pole arc angle α01 of the first set of magnet slots 21 can satisfy: α01=(0.59×360°) / P, and the pole arc angle α02 of the second set of magnet slots 22 can satisfy: α02=(0.33×360°) / P, where P is the number of poles of the rotor.

[0126] Based on the above scheme, when the angles α1 and α2 are within the aforementioned range, the entire area enclosed by the first set of magnet slots 21 and the second set of magnet slots 22 becomes larger, resulting in a greater quantity of magnets 50 and a higher reluctance torque, thus improving power density. Simultaneously, the rotor yoke ratio is maintained, meeting strength requirements. Furthermore, it reduces the high-order harmonic content in the motor's main magnetic field, lowering the electromagnetic force by 24*p, thereby reducing motor noise and vibration and improving NVH performance.

[0127] In some embodiments, such as Figure 4 As shown, Figure 4 for Figure 1 The second schematic diagram of the rotor lamination shows that the first set of magnet slots 21 may include two first magnet slots 211. The two first magnet slots 211 extend from one end to the other, towards the center of the lamination body 10, and are inclined towards each other. The included angle between the two first magnet slots 211 forms the aforementioned angle α1. Based on the above scheme, the structure of the first set of magnet slots 21 is relatively simple, which can increase the installation area of ​​the magnets and ensure power output.

[0128] In some embodiments, the two first magnet slots 211 are symmetrically arranged about a first axis (i.e., the d-axis) passing through the center of the lamination body 10. For the convenience of the description of the embodiments below, Figure 2 The axis that is separated from the d-axis by an angle equal to the first preset mechanical angle is defined as the q-axis. The q-axis is also the axis of symmetry or dividing line between two adjacent magnet mounting sections 20. The first preset mechanical angle = 180° / P, where P is the number of poles in the motor. For example, when the number of poles in the motor is 6, the first preset mechanical angle = 30°. In the concept of electrical angle, since the electrical angle is a multiple of the mechanical angle (e.g., when the motor rotor has 6 rotor poles and 3 pole pairs), the electrical angle is 3 times the mechanical angle. Therefore, according to the concept of electrical angle, the d-axis and q-axis differ by 90° electrical angle.

[0129] In some embodiments, such as Figure 4As shown, the first set of magnetic slots 21 also includes at least one second magnetic slot 212. The at least one second magnetic slot 212 is located between the ends of the two first magnetic slots 211 facing the center of the lamination body 10. Thus, the arrangement trajectory line of the first set of magnetic slots 21 (i.e., the first convex trajectory line) is U-shaped. Based on this design, the number of reinforcing ribs can be increased, ensuring the structural strength of the rotor and preventing the risk of fracture failure in ultra-high speed motor rotors due to stress concentration at the magnetic isolation bridge and reinforcing ribs of the rotor lamination 100 caused by centrifugal force during rotor rotation.

[0130] In some embodiments, such as Figure 4 As shown, there are multiple second magnet slots 212, arranged sequentially along the arrangement direction of the two first magnet slots 211 towards the center of the lamination body 10. For example, there can be two second magnet slots 212. Of course, in other examples, there can be three or four, etc. Thus, by increasing the number of second magnet slots 212, the number of reinforcing ribs can be further increased, further improving the structural strength of the rotor and its maximum speed.

[0131] In some other embodiments, the first set of magnet slots 21 may not have a second magnet slot 212, and may consist only of two first magnet slots 211. In this way, the arrangement trajectory of the first set of magnet slots 21 is V-shaped. This structure is simple and has high assembly efficiency.

[0132] In some embodiments, such as Figure 4 As shown, the second set of magnet slots 22 may include two third magnet slots 221. The two third magnet slots 221 extend from one end to the other, towards the center of the lamination body 10, and are inclined towards each other. The included angle between the two third magnet slots 221 forms an angle α2. Thus, the structure of the second set of magnet slots 22 is relatively simple, which can increase the installation area of ​​the magnets and ensure power output.

[0133] In some embodiments, the second set of magnet slots 22 further includes at least one fourth magnet slot 222. The at least one fourth magnet slot 222 is located between the ends of the two third magnet slots 221 facing the center of the lamination body 10. Thus, the arrangement trajectory line of the second set of magnet slots 22 (i.e., the second convex trajectory line) is U-shaped. Based on this scheme, on the one hand, the amount of magnets can be increased to improve the output power and output torque of the motor; on the other hand, the number of portions (hereinafter referred to as reinforcing ribs) located between two adjacent magnet slots on the lamination body 10 can be increased, ensuring the structural strength of the rotor and preventing the risk of fracture failure in ultra-high speed motor rotors due to stress concentration at the magnetic isolation bridge and reinforcing ribs caused by centrifugal force during rotor rotation.

[0134] The number of fourth magnet slots 222 can be one or more. This application uses one fourth magnet slot 222 as an example for illustration.

[0135] In some other embodiments, the second set of magnet slots 22 may not have a fourth magnet slot 222, but may consist only of two third magnet slots 221. In this way, the arrangement trajectory of the second set of magnet slots 22 is V-shaped. This structure is simple and has high assembly efficiency.

[0136] In some embodiments, the first set of magnetic steel grooves 21 and the second set of magnetic steel grooves 22 can be arranged in a double U-shape, a double V-shape, or a U+V-shape.

[0137] In some embodiments, a first reinforcing rib 31 is formed in the portion of the lamination body 10 located between the first magnet groove 211 and the adjacent second magnet groove 212. A second reinforcing rib 32 is formed in the portion of the lamination body 10 located between two adjacent second magnet grooves 212. A third reinforcing rib 33 is formed in the portion of the lamination body 10 located between the third magnet groove 221 and the adjacent fourth magnet groove 222. Along the circumferential direction of the lamination body 10, the first reinforcing rib 31 and the third reinforcing rib 33, as well as the second reinforcing rib 32 and the third reinforcing rib 33, are staggered. Based on the above scheme, the structural strength of the lamination body 10 can be improved by the first reinforcing rib 31, the second reinforcing rib 32, and the third reinforcing rib 33. Simultaneously, because the first reinforcing rib 31 and the third reinforcing rib 33, as well as the second reinforcing rib 32 and the third reinforcing rib 33, are staggered, the strength of each position of the lamination body 10 can be improved, resulting in a more uniform improvement in the structural strength of each position of the lamination body 10.

[0138] The inventors discovered that the magnetic domains in permanent magnets 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 easily corrosive and oxidizing environments, the magnetic domain arrangement is disrupted, resulting in demagnetization. In the embodiments of this application, due to the requirement of high power density, the unloaded air gap magnetic flux density is as high as 0.8T (compared to 0.6T-0.7T in typical electromagnetic schemes), making the magnets highly susceptible to demagnetization, especially in environments such as... Figure 5 At point a in the middle Figure 6 At point b and Figure 7 The three areas shown at point c in the middle are severely demagnetized. Figure 5 This is one of the demagnetization region simulation diagrams provided in the embodiments of this application. Figure 6 This is the second simulation diagram of the demagnetization region provided in the embodiments of this application. Figure 7 This is the third simulation diagram of the demagnetization region provided in the embodiments of this application.

[0139] To address the demagnetization problem, optionally, the included angle region of the two first magnet slots 211 can be defined as a first region, the side of the first magnet slot 211 that encloses the first region can be defined as a first side, and the first magnet slot 211 can also include a second side opposite to the first side. For example... Figure 8 As shown, Figure 8 This is a partial structural schematic diagram of another rotor lamination 100 provided in an embodiment of this application. A first magnetic blocking groove 41 is provided on the first side facing the center of the lamination body 10, which is recessed into the first region. A second magnetic blocking groove 42 is provided on the second side away from the center of the lamination body 10, which is recessed in the direction away from the first region.

[0140] The first magnetically blocking groove 41 extends along the extension direction of the first magnetic groove 211 (i.e. Figure 8 The length of the second magnetic groove 42 in the X direction and / or the length of the second magnetic groove 42 along the extension direction of the first magnetic groove 211 is greater than or equal to twice the length of the first magnetic groove 211 in the extension direction, and less than or equal to three times the length of the first magnetic groove 211 in the extension direction.

[0141] In this way, the first magnetic resisting groove 41 and / or the second magnetic resisting groove 42 are shaped like long knives, which increases the magnetic resistance of the reverse magnetic field at the corner region of the magnet and suppresses the demagnetizing field strength.

[0142] Alternatively, the area between the two third magnet grooves 221 is defined as the second region, the side of the third magnet groove 221 that forms the second region is defined as the third side, and a third magnetic blocking groove 43 that is recessed into the second region is provided on the third side at a position away from the center of the lamination body 10.

[0143] The third magnetically resistive groove 43 extends along the direction of the third magnetic groove 221 (i.e.) Figure 8 The length of the third magnetic groove 43 in the Y direction is greater than or equal to twice the length of the third magnetic groove 221 in the extension direction, and less than or equal to three times the length of the third magnetic groove 221 in the extension direction. In this way, the third magnetic groove 43 is shaped like a long knife, which increases the magnetic resistance of the reverse magnetic field at the corner region of the magnet and suppresses the demagnetizing field strength.

[0144] Setting at least one of the first magnetic blocking groove 41, the second magnetic blocking groove 42 and the third magnetic blocking groove 43 into a long knife shape is not conducive to the segmentation of the magnet along the plane of the lamination body 10, because after segmentation along the plane of the lamination body 10, the long knife-shaped magnetic blocking groove will lose its support, which may cause the magnet segment to fly out at high speed.

[0145] Based on this, in some embodiments, the magnets accommodated in the first set of magnet slots 21 and the second set of magnet slots 22 may include a plurality of magnet units arranged axially along the rotor lamination 100. Thus, as... Figure 9 As shown, Figure 9This is a partial structural diagram of another rotor lamination provided in an embodiment of this application. The magnet is divided into multiple segments axially, which can reduce the eddy current loss of the magnet and at the same time ensure that the magnet 50 will not fly out at high speed.

[0146] The aforementioned first reinforcing rib 31, second reinforcing rib 32, and third reinforcing rib 33 are used to share the stress of the magnet pressing against the edge of the magnet slot when the rotor rotates. Along the arrangement direction of the first magnet slot 211 and the adjacent second magnet slot 212, as shown... Figure 14 As shown, Figure 14 This is a partial structural diagram of another rotor lamination provided in an embodiment of this application. The dimension of the first reinforcing rib 31 is a1. Along two adjacent second magnet slots 212 ( Figure 4 The arrangement direction of the second reinforcing rib 32 is defined as a2. Generally, the smaller a1 and a2 are, the thinner the reinforcing rib is, resulting in less magnetic leakage in the rotor magnetic field with the same amount of magnets, thus increasing power density. However, this also reduces the maximum rotor speed it can handle, preventing the motor from reaching ultra-high speeds (>30000 rpm). Therefore, a1 and a2 can optionally satisfy: 1.2mm ≤ a1 ≤ 1.8mm, 1.2mm ≤ a2 ≤ 1.8mm. Specifically, a1 and a2 can be 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, or 1.8mm. This balances power density and motor speed, ensuring the motor can meet the 30000 rpm requirement.

[0147] In some embodiments, with the amount of magnets remaining constant, changing the total thickness of the reinforcing ribs (a1+a2×2) results in changes in power density and stress as follows: Figure 10 , Figure 11 and Figure 12 As shown, Figure 10 This is a graph showing the maximum power as a function of thickness. Figure 11 This is a graph showing the stress limit as a function of thickness. Figure 12 The graph shows the leakage flux coefficient as a function of thickness, exhibiting a linear decreasing trend within a certain range. As the thickness of the reinforcing rib increases, the leakage flux coefficient continuously increases, while the power density decreases accordingly. At a certain rotational speed, the stress at the reinforcing rib also decreases, increasing the maximum tolerable rotational speed. Based on this, optionally, a1 and a2 also satisfy: 3.7mm ≤ (a1 + a2 × 2) ≤ 4.8mm. For example, (a1 + a2 × 2) can be 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.55mm, 4.6mm, 4.7mm, and 4.8mm. This allows for a balance between power density and motor speed.

[0148] In some embodiments, the area of ​​the first group of magnetic slots 21 is S1, and the area of ​​the first reinforcing part is S2, where S1 and S2 satisfy: 0.13 ≤ S2 / S1 ≤ 0.2. For example, the value of S2 / S1 can be 0.13, 0.14, 0.142, 0.15, 0.155, 0.16, 0.17, 0.181, 0.19, or 0.2, etc. It should be noted that the first reinforcing part is the area between the spaced magnetic slots of the first group of magnetic slots 21. For example, as... Figure 4 As shown, S1 is the area of ​​the first magnet groove 211 and the second magnet groove 212. S2 is the area of ​​the first reinforcing rib 31 and the second reinforcing rib 32.

[0149] When the area of ​​the first set of magnet slots 21 increases, the area of ​​magnets 50 that can be accommodated in the first set of magnet slots 21 increases. A larger magnet 50 area means that more magnetic material can be arranged on the rotor, thereby providing a stronger magnetic field. Increasing the magnet 50 area can also increase the magnetic flux. Therefore, the strong magnetic field generated by a larger magnet 50 area helps to improve the electromagnetic conversion efficiency of the motor and allows more magnetic flux to pass through, all of which contribute to increasing the motor's power and maximum torque.

[0150] Given a fixed area of ​​rotor lamination 100 and a fixed area for arranging the first set of magnet slots 21, increasing the area of ​​the first set of magnet slots 21 will correspondingly reduce the area that the first reinforcing part can occupy. However, when the motor needs to reach high speeds, the magnets 50 will exert stress on the rotor lamination 100 during operation. If the area of ​​the first set of magnet slots 21 is not considered when increasing the area, the rotor lamination 100 may be unable to meet the stress requirements, resulting in deformation or damage. Moreover, increasing the area of ​​the magnets 50 means increasing their mass; at the same speed, a larger magnet 50 will exert greater stress on the rotor lamination 100.

[0151] Therefore, when designing the topology of the rotor lamination 100, it is necessary to increase the area of ​​the first set of magnet slots 21 to accommodate a larger magnet 50, and at the same time, it is necessary to have a first reinforcing part of a corresponding size in the first set of magnet slots 21 so that the rotor lamination 100 has good mechanical strength.

[0152] If the ratio of the area of ​​the first reinforcing part to the area of ​​the first set of magnetic steel grooves 21 is less than 0.13, the area of ​​the first reinforcing part is too small under the premise of meeting the power and high speed requirements of the motor, which may lead to low mechanical strength of the first reinforcing part, and deformation or damage of the first reinforcing part due to stress. If the ratio of the area of ​​the first reinforcing part to the area of ​​the first set of magnetic steel grooves 21 is greater than 0.2, the area of ​​the first reinforcing part is too large under the premise of meeting the power and high speed requirements of the motor, which may lead to magnetic leakage and have an adverse effect on the power of the motor.

[0153] According to the rotor lamination 100 of the present application embodiment, by ensuring that the area S1 of the first set of magnet slots 21 and the area S2 of the first reinforcing part satisfy: 0.13≤S2 / S1≤0.2, when the rotor lamination 100 is topologically designed, if it is necessary to increase the power of the motor by increasing the amount of magnets 50, the area of ​​the magnets 50 will increase and the area of ​​the first reinforcing part will also change accordingly, which can improve the mechanical strength of the rotor lamination 100. This avoids the rotor lamination 100 being unable to bear the stress generated by the motor at high speed after the power is increased, so that the rotor lamination 100 can meet the performance requirements of the motor to achieve both high power and high speed at the same time.

[0154] In some embodiments, S1 and S2 satisfy: 0.15 ≤ S2 / S1 ≤ 0.18. For example, the value of S2 / S1 can be 0.15, 0.155, 0.16, 0.17, or 0.18, etc. If the ratio of the area of ​​the first reinforcing part to the area of ​​the first set of magnetic steel grooves 21 in the first region 3 is less than 0.15, the area of ​​the first reinforcing part is small under the premise of meeting the power and high speed requirements of the motor, which may lead to local deformation or damage of the first reinforcing part due to stress. If the ratio of the area of ​​the first reinforcing part to the area of ​​the first set of magnetic steel grooves 21 in the first region 3 is greater than 0.18, the area of ​​the first reinforcing part is large under the premise of meeting the power and high speed requirements of the motor, which may lead to magnetic leakage and adversely affect the power of the motor.

[0155] By keeping the ratio of the area of ​​the first reinforcing part to the area of ​​the first set of magnet slots 21 within this range, when it is necessary to increase the amount of magnets 50 to increase the power of the motor, the area of ​​the first reinforcing part will also change accordingly as the area of ​​the magnets 50 increases. This can improve the mechanical strength of the rotor lamination 100, so as to avoid the rotor lamination 100 being unable to bear the stress generated by the motor under high speed after the power is increased. Thus, the rotor lamination 100 can meet the performance requirements of the motor to achieve both high power and high speed at the same time.

[0156] Additional, such as Figure 13 As shown, Figure 13The graph shows the power density as a function of magnet area. Power density is also directly related to the cross-sectional area of ​​the magnet. Increasing the length and width of the magnet can significantly improve the power density.

[0157] It can be seen that the amount of magnets used is also closely related to the change in power density. The longer the length of the first magnet slot 211 and the second magnet slot 212, the longer the length of the magnets installed in the first magnet slot 211 and the second magnet slot 212. The wider the first magnet slot 211 and the second magnet slot 212, the wider the magnets installed in the first magnet slot 211 and the second magnet slot 212. The larger the cross-sectional area of ​​the magnets, the greater the power density of the motor.

[0158] Based on this, in some embodiments, such as Figure 14 As shown, Figure 14 This is a partial structural diagram of a rotor lamination provided in an embodiment of this application. The dimension L1 of the first magnet slot 211 in the extension direction satisfies: 7.2mm ≤ L1 ≤ 9.1mm, optionally, L1 = 7.9mm. The dimension L2 of the second magnet slot 212 in the extension direction satisfies: 16.5mm ≤ L2 ≤ 18.4mm, optionally, L2 = 17.2mm. Thus, the longer the length of the first magnet slot 211 and the second magnet slot 212, the longer the magnet installed in the first magnet slot 211 and the second magnet slot 212, which is beneficial for increasing the cross-sectional area of ​​the magnet and improving the power density of the motor.

[0159] In some embodiments, the dimension W1 of the first magnet slot 211 perpendicular to the extension direction satisfies: 7mm ≤ W1 ≤ 7.6mm, optionally W1 = 7.2mm. The dimension W2 of the second magnet slot 212 perpendicular to the extension direction satisfies: 7mm ≤ W2 ≤ 7.6mm, optionally W2 = 7.2mm. Thus, the larger the width of the first magnet slot 211 and the second magnet slot 212, the larger the width of the magnet installed in the first magnet slot 211 and the second magnet slot 212, which is beneficial for increasing the cross-sectional area of ​​the magnet and improving the power density of the motor.

[0160] based on Figure 14 The ratio of L1 / L2 in the first magnet slot 211 shown can be [value missing], the ratio of L1 to W1 can be [value missing], and the ratio of L2 / W2 can be [value missing]. As described above, the magnetic bridge and reinforcing ribs of the rotor lamination 100 will be subject to significant stress concentration. To reduce the risk of fracture failure of the rotor lamination 100, the stress concentration at the magnetic bridge and reinforcing ribs can be reduced by adjusting the thickness of the rotor yoke.

[0161] Reference Figure 15 , Figure 15This is a schematic diagram of another rotor lamination provided in an embodiment of this application. Research has shown that when the motor reaches its maximum speed, the stress concentration at the reinforcing ribs between the first set of magnet slots 21 is also related to the ratio of the rotor yoke thickness d1 to the rotor's single-sided radius d2. The lamination body 10 has mounting holes for shaft installation, and multiple magnet mounting portions 20 are located around the mounting holes and arranged circumferentially. The rotor yoke refers to the portion of the lamination body 10 located between the mounting holes and the multiple magnet mounting portions 20. The rotor yoke thickness d1 refers to the distance from the first set of magnet slots 21 to the mounting holes, and the rotor's single-sided radius d2 refers to the distance from the outer edge of the lamination body 10 to the mounting holes.

[0162] In this embodiment, the rotor yoke is not provided with any structure that affects the strength of the rotor yoke, such as de-weighting holes, stress buffer grooves, or other fragile parts that are prone to breakage.

[0163] Based on a large number of simulation results, it is concluded that Figure 16 The pattern of the curves shown. Figure 16 The diagram shows the stress variation of d1 / d2 and the stiffener, combined with, for example... Figure 17 and Figure 18 , Figure 17 The stress distribution diagram is shown when the rotor yoke ratio d1 / d2 is 0.46. Figure 18 The diagram shows the stress distribution when the rotor yoke ratio d1 / d2 is 0.4. As the rotor yoke ratio d1 / d2 increases from 0.36 to 0.46, the stress at the reinforcing ribs between the first set of magnet slots 21 decreases with the increase of the rotor yoke ratio d1 / d2. As the rotor yoke ratio d1 / d2 increases from 0.46 to 0.61, the rotor mass increases, and the rotor stress is proportional to the mass. The stress at the reinforcing ribs between the first set of magnet slots 21 increases with the increase of the rotor yoke ratio d1 / d2.

[0164] Based on this, the rotor yoke ratio d1 / d2 can optionally satisfy 0.4 ≤ d1 / d2 ≤ 0.61. Specifically, d1 / d2 can be 0.4, 0.45, 0.5, 0.55, 0.6, 0.61, etc. When the rotor yoke ratio d1 / d2 is within this range, the stress on the reinforcing ribs between the first set of magnet slots 21 is relatively small when the rotor rotates at 30,000 rpm. However, when the ratio is in other ranges, the stress on the reinforcing ribs between the first set of magnet slots 21 is very likely to exceed the yield limit of the rotor material. Therefore, only when the rotor yoke ratio d1 / d2 is within the closed interval [0.4, 0.61] can the thickness of the reinforcing ribs between the first set of magnet slots 21 be appropriately reduced when the motor reaches the same limiting speed. This effectively reduces leakage flux and increases the main magnetic flux content while ensuring stable operation of the motor at ultra-high speeds (30,000 rpm), thereby improving the power density and torque density of the motor.

[0165] As described above, the rotor experiences centrifugal force during rotation, with the reinforcing ribs and magnetic bridge bearing the main rotor stress. As the rotational speed increases, the magnetic bridge and reinforcing ribs also face a significant risk of stress concentration, necessitating a corresponding increase in the strength of the reinforcing rib area to ensure that the high-speed requirements are met without exceeding the material's yield strength. However, increasing the magnetic bridge's strength is accompanied by severe rotor magnetic leakage, leading to a decrease in motor performance. Therefore, to achieve the same limiting speed, the reinforcing ribs should be rationally arranged to minimize their thickness.

[0166] Research has shown that if the same limiting speed is reached, the reinforcing ribs (including the first reinforcing rib 31 and the second reinforcing rib 32) between the first set of magnet slots 21 are the main stress-bearing objects of the rotor. The length and width of these reinforcing ribs directly affect the overall strength of the rotor. If they are too wide, it will lead to serious magnetic leakage. If they are too narrow, the strength will not meet the requirements and there will be a risk of breakage. The size of the reinforcing ribs should be matched reasonably.

[0167] In some embodiments, such as Figure 14 and Figure 19 As shown, Figure 19 This is a partial structural diagram of a rotor lamination provided in an embodiment of this application. The dimension of the first reinforcing rib 31 along the arrangement direction perpendicular to the first magnet slot 211 and the adjacent second magnet slot 212 is K1. The dimension of the second reinforcing rib 32 along the arrangement direction of two adjacent second magnet slots 212 is K2. K1 and the aforementioned a1 satisfy: 4.8≤K1 / a1≤10.2. Specifically, K1 / a1 can be 4.8, 5, 6, 7, 8, 9, 10, or 10.2. And / or, K2 and the aforementioned a2 satisfy: 4.8≤K2 / a2≤10.2. K2 / a2 can be 4.8, 5, 6, 7, 8, 9, 10, or 10.2.

[0168] When K1, a1, K2, or a2 meet the above conditions, both the strength requirements are met and the leakage flux coefficient is relatively low. Since the rotor yoke needs to maintain a suitable height, the larger the values ​​of K1 / a1 and K2 / a2, the smaller the space between the first set of magnet slots 21 and the second set of magnet slots 22. The stress will be correspondingly distributed to the reinforcing ribs (including the first reinforcing rib 31 and the second reinforcing rib 32) between the second set of magnet slots 22. When this exceeds the limit, these reinforcing ribs will experience severe stress concentration problems. If K1 / a1 and K2 / a2 are too small, the thickness of the reinforcing ribs will be directly increased, leading to increased leakage flux and negatively impacting performance.

[0169] For example, such as Figure 20 and Figure 21 As shown, Figure 20 The stress diagram is shown when K1 / a1 is less than 4.8 at the limiting speed. Figure 21 This is a stress diagram when K2 / a2 is greater than 7.4 at the limiting speed.

[0170] In some embodiments, the dimension of the third reinforcing rib 33 is a3 along the arrangement direction of the third magnet groove 221 and the adjacent fourth magnet groove 222. The dimension of the third reinforcing rib 33 perpendicular to the arrangement direction of the third magnet groove 221 and the adjacent fourth magnet groove 222 is K3; a3 and K3 satisfy: 5.2≤K3 / a3≤7.4, specifically, K3 / a3 can be 5.2, 6, 7 or 7.4.

[0171] Because the bearing area of ​​the magnets in the second set of magnet slots 22 is smaller, the stress it bears is less than that in the first set of magnet slots 21. Therefore, when K3 / a3 is within the aforementioned range, the reinforcing ribs between the second set of magnet slots 22 can effectively share the stress with the reinforcing ribs between the first set of magnet slots 21, while also considering process conditions. When the ratio exceeds the limit, if the ratio is too large, the usable area of ​​the second set of magnet slots 22 decreases; if it is too small, it leads to severe magnetic leakage, which is detrimental to overall performance.

[0172] As described above, the rotor is subjected to centrifugal force during rotation, and the reinforcing ribs and magnetic bridge bear the main rotor stress. With increasing rotational speed, the magnetic bridge and reinforcing ribs also face a significant risk of stress concentration, necessitating a corresponding increase in the strength of the reinforcing rib area to ensure that the high-speed requirements are met without exceeding the material's yield strength. Figure 22 As shown, Figure 22 The stress diagram of the rotor lamination provided in the embodiment of this application is shown. The unit of the values ​​is MPa. In the stress simulation diagram at 30000rpm, it can be seen that stress concentration occurs in the magnetic isolation bridge, and the stress is extremely high, reaching a maximum of 1031MPa, which is difficult for the mechanical strength of the rotor to withstand.

[0173] To meet the requirements of lightweight design and stress concentration reduction, stress relief holes are provided in the rotor lamination 100, which can effectively reduce the motor weight. The size and location of these stress relief holes need to be considered when designing for excessive weight. The arrangement of these stress relief holes can affect stress concentration issues such as those caused by stiffeners, and stress relief holes themselves can also experience some stress concentration. Therefore, it is necessary to rationally arrange the location and size of the stress relief holes.

[0174] Optional, such as Figure 23 As shown, Figure 23 This is a partial structural diagram of another rotor lamination provided in an embodiment of this application. When the first set of magnet slots 21 and the second set of magnet slots 22 are arranged in a double V-shape, the lamination body 10 is also provided with a first stress relief hole 101. The first stress relief hole 101 is located on the side of the first magnet slot 211 facing away from the first region. The first stress relief hole 101 can reduce the weight of the rotor lamination 100 and effectively release the stress of some of the reinforcing ribs between the two first magnet slots 211.

[0175] When the first set of magnet slots 21 and the second set of magnet slots 22 are arranged in a double V-shape, the distribution of reinforcing ribs is relatively small, and the stress is relatively concentrated. The stress concentration can be reduced by using the first stress relief hole 211. At the same time, when arranged in a double V-shape, the area of ​​the magnet slots is small, so there is no need to require an excessively large rotor yoke. The strength is sufficient, so the first stress relief hole 101 can be provided.

[0176] In some embodiments, such as Figure 24 As shown, Figure 24 This is a partial structural diagram of another rotor lamination provided in an embodiment of this application. The distance from the geometric center of the first stress relief hole 101 to the center of the lamination body 10 is R2. The lamination body 10 is circular, and its radius is R1. R1 and R2 satisfy: 0.55≤R2 / R1≤0.65. The line connecting the geometric center of the first stress relief hole 101 and the center of the lamination body 10 is the second axis, and the angle θ1 between the second axis and the d-axis satisfies: 9°≤θ1≤13°. The reinforcing rib between the two first magnet slots 211 passes through the d-axis of the lamination body 10. Thus, the first stress relief hole 101 is positioned near the reinforcing rib between the two first magnet slots 211 to ensure that the stress in the reinforcing rib between the two first magnet slots 211 does not exceed the yield strength of the material, preventing breakage during high-speed motor rotation. Furthermore, when R2 / R1 is within the aforementioned range, it can simultaneously reduce the impact on the magnetic circuit at the q-axis and improve stress. If the distance R2 from the geometric center of the first stress relief hole 101 to the center of the lamination body 10 is too large, it will affect the magnetic circuit of the rotor lamination 100 at the q-axis; if it is too small, it will not be able to improve the stress of the reinforcing ribs between the two first magnet slots 211. In addition, one end of the first magnet slot 211 can face the first stress relief hole 101 and be positioned opposite to the first stress relief hole 101, which can alleviate the stress concentration problem near the first magnet slot 211.

[0177] In some embodiments, the lamination body 10 is further provided with a second stress relief hole 102. The second stress relief hole 102 is located on the side of the first stress relief hole 101 opposite to the first magnet slot 211. The second stress relief hole 102 can further reduce the weight of the rotor lamination 100 and further reduce the internal stress of the lamination body 10. In addition, the second stress relief hole 102 is located close to the q-axis, which can alleviate the problem of stress concentration between the magnet mounting parts.

[0178] In some embodiments, at least one third stress relief hole 103 is provided in the second included angle region. The third stress relief hole 103 can reduce the weight of the rotor and reduce the stress in the second included angle region.

[0179] In some embodiments, a fourth reinforcing rib 34 is formed on the portion of the lamination body 10 located between the two third magnet slots 221. At least a portion of the third stress relief hole 103 is opposite to the fourth reinforcing rib 34 along the radial direction of the lamination body 10. Thus, the centrifugal tension on the fourth reinforcing rib 34 can be released by means of the third stress relief hole 103, allowing for a reduction in the size of the fourth reinforcing rib 34, reducing motor leakage flux, and ensuring the strength of the motor's magnetic field.

[0180] In some embodiments, such as Figure 25 As shown, Figure 25 This is a partial structural diagram of another rotor lamination provided in an embodiment of this application. The second set of magnet slots 22 further includes a fourth magnet slot 222, which is located between the ends of the two third magnet slots 221 facing the center of the lamination body 10. At least a portion of the third stress relief hole 103 is opposite to the fourth magnet slot 222 along the radial direction of the lamination body 10. In this way, the third stress relief hole 103 is centrally located, and the stress in the second included angle region can be effectively reduced by means of the third stress relief hole 103.

[0181] In some embodiments, the number of third stress relief holes 103 is two, and the two third stress relief holes 103 are located on opposite sides of the d-axis and are symmetrically arranged about the d-axis. This simplifies the structure, effectively reduces stress, and avoids the influence of the third stress relief holes 103 on the d-axis magnetic circuit of the motor. For example, as shown... Figure 26 and Figure 27 , Figure 26 Stress diagram for a system without stress relief holes. Figure 27 This is a stress diagram for a structure with stress relief holes.

[0182] Different stress relief holes can have different effects on stress. For example, Figure 28 , Figure 29 and Figure 30 , Figure 28 The stress diagram provided in this embodiment of the application shows a third stress relief hole 103. Figure 29 The stress diagram provided in this application embodiment includes a second stress relief hole 102. Figure 30 A stress diagram provided for an embodiment of this application, which simultaneously includes a second stress relief hole 102 and a third stress relief hole 103.

[0183] By comparison Figure 28 and Figure 30 It can be seen that the function of the second stress relief hole 102 is to alleviate the stress concentration problem between the magnet mounting parts. (This is achieved through comparison.) Figure 28 and Figure 29 It can be seen that the function of the third stress relief hole 103 is to alleviate the stress concentration problem at the edge of the rotor lamination.

[0184] In some embodiments, such as Figure 24 As shown, the distance d5 from the third stress relief hole 103 to the outer edge of the lamination body 10 satisfies: 0.9mm ≤ d5 ≤ 1.3mm. Specifically, d5 can be 0.9mm, 1.0mm, 1.1mm, 1.2mm, or 1.3mm. This avoids the influence of the third stress relief hole 103 on the d-axis magnetic circuit of the motor.

[0185] The size of the reinforcing rib between the two deduplication holes affects the magnetic circuit. Based on this, in some embodiments, such as... Figure 31 As shown, Figure 31 This is a partial structural diagram of another rotor lamination provided in an embodiment of this application. The distance between the two third stress relief holes 103 is d3, and the distance from the common geometric center of the two third stress relief holes 103 to the outer edge of the lamination body 10 is d4. d3 and d4 satisfy: 2.5 ≤ d4 / d3 ≤ 4. Specifically, d4 / d3 can be 2.5, 2.6, 2.7, 2.8, 3, 3.2, 3.4, 3.6, 3.8, or 4. Within this range, d4 / d3 can effectively control the impact on the magnetic circuit and improve NVH (Noise, Vibration, and Harshness).

[0186] In some embodiments, the third stress relief hole 103 has a circumferential dimension of L3 along the lamination body 10 and a radial dimension of W3 along the lamination body 10. L3 and W3 satisfy: 1.4 ≤ L3 / W3 ≤ 1.8. Specifically, L3 / W3 can be 1.4, 1.5, 1.6, 1.7, or 1.8. This can simultaneously reduce the impact on the magnetic circuit and reduce the stress on the reinforcing ribs.

[0187] In some embodiments, such as Figure 32 As shown, Figure 32 This is a schematic diagram of another rotor lamination structure provided in an embodiment of this application. The lamination body 10 is also provided with a stress relief groove 104. Along the circumference of the lamination body 10, the stress relief groove 104 is located between two adjacent magnet mounting portions 20, and the stress relief groove 104 penetrates the outer edge of the lamination body 10. In this way, the stress between two adjacent magnet mounting portions 20 can be released by means of the stress relief groove 104.

[0188] The shape of the stress relief groove includes, but is not limited to, rectangles, circles, irregular shapes, etc., and this application does not make any specific limitation in this regard.

[0189] In some embodiments, the stress relief groove 104 passes through the q-axis. This ensures that the distances from the stress relief groove 104 to the two adjacent magnet mounting portions 20 are approximately equal, resulting in better stress relief balance.

[0190] In some embodiments, such as Figure 33 As shown, Figure 33 This is a schematic diagram of another rotor lamination structure provided in an embodiment of this application. The lamination body 10 also has a fourth stress relief hole 105. Along the circumferential direction of the lamination body 10, the fourth stress relief hole 105 is located between two adjacent magnet mounting portions 20, and the fourth stress relief hole 105 is circumferentially closed. The fourth stress relief hole 105 passes through the q-axis. Thus, by means of the fourth stress relief hole 105, the stress between two adjacent magnet mounting portions 20 can be further released.

[0191] In some embodiments, such as Figure 31 As shown, along the extension direction of the d-axis, the fourth stress relief hole 105 is located between the second magnet groove 212 and the mounting hole. Along the extension direction of the d-axis, the distance between the fourth stress relief hole 105 and the second magnet groove 212 is m1, the size of the fourth stress relief hole 105 is m2, and the distance between the fourth stress relief hole 105 and the mounting hole is m3. m1, m2, and m3 satisfy: m1:m2:m3=(3-3.5):(5-6):(7-8). In this way, the stress distribution of the reinforcing ribs between the first set of magnet grooves 21 is more uniform.

[0192] In some embodiments, such as Figure 31 As shown, the portion of the fourth stress relief hole 105 located between the q-axis and the d-axis includes a first inner sidewall 1051 and a second inner sidewall 1052. The first inner sidewall 1051 and the second inner sidewall 1052 are arranged radially along the lamination body 10, and the included angle θ5 between the first inner sidewall 1051 and the second inner sidewall 1052 satisfies: 65°≤θ5≤70°. Specifically, θ5 can be 65°, 66°, 67°, 68°, 69°, or 70°. This results in better weight reduction of the fourth stress relief hole 105, more uniform stress in the magnet slot area and the fourth stress relief hole 105 itself, and lower impact on the magnetic circuit.

[0193] Those skilled in the art know that the magnets are subjected to compressive stress from the rotor laminations 100 when the rotor rotates at high speed. To avoid stress concentration on the contact surface between the magnets and the rotor laminations 100, to ensure that the magnets do not crack due to stress, and to ensure that the magnetic bridge does not experience stress concentration due to the centrifugal force of the magnets, optionally, at least one magnet slot in the first set of magnet slots 21 and the second set of magnet slots 22 has a groove on its edge that is recessed away from the magnet slot. (Refer to...) Figure 24 The included angle θ2 between at least one inner wall of the groove and the inner wall of the adjacent magnet slot satisfies: 5°≤θ2≤8°. This avoids stress concentration on the contact surface between the magnet and the rotor lamination 100, preventing magnet breakage, and also ensures that the magnetic bridge does not experience stress concentration due to the centrifugal force of the magnet. Furthermore, to address stress issues, such as... Figure 34 As shown, Figure 34This is a schematic diagram of a 6-pole double-V rotor lamination structure provided in an embodiment of this application.

[0194] To further reduce the stress on the lamination body 10, in some embodiments, such as Figure 23 As shown, two first magnetic grooves 211 are provided on the side facing the center of the stamping body 10, and a second magnetic groove 212 is provided on the side facing away from the center of the stamping body 10. Both the first magnetic groove 211 and the second magnetic groove 212 are connected to the first magnetic groove 211. Similarly, two third magnetic grooves 221 are provided on the side facing the center of the stamping body 10, and a fourth magnetic groove 2212 is provided on the side facing away from the center of the stamping body 10. Both the third magnetic groove 2211 and the fourth magnetic groove 2212 are connected to the third magnetic groove 221. The portion of the stamping body 10 between the second magnetic groove 212 and the outer edge of the stamping body 10 forms a first magnetic bridge 101a, and the portion of the stamping body 10 between the fourth magnetic groove 2212 and the outer edge of the stamping body 10 forms a second magnetic bridge 102a.

[0195] from Figures 35-37 As shown, Figure 35 This is one of the stress distribution diagrams of the rotor laminations provided in the embodiments of this application. Figure 36 This is the second stress distribution diagram of the rotor lamination provided in the embodiments of this application. Figure 37 This is the third stress distribution diagram of the rotor lamination provided in the embodiments of this application. Figures 35-37 As can be seen, the stress of the magnet is mainly concentrated in the first magnetic isolation bridge 101a and the second magnetic isolation bridge 102a, followed by the reinforcing ribs between the two first magnet grooves 211 and the reinforcing ribs between the two second magnet grooves 212.

[0196] from Figures 38-40 As shown, Figure 38 This is one of the deformation contour maps of the rotor laminations provided in the embodiments of this application. Figure 39 This is the second deformation contour map of the rotor lamination provided in the embodiments of this application. Figure 40 This is the third deformation contour map of the rotor lamination provided in the embodiments of this application, from... Figures 37-39 It can be seen that the deformation at the position corresponding to the q-axis on the outer edge of the stamp body 10 differs greatly from the deformation at the position corresponding to the d-axis, resulting in severe stress.

[0197] To address the aforementioned issues, in some embodiments, stress relief grooves 104, first stress relief holes 101, and second stress relief holes 102 are formed from the inside out along the q-axis, and a third stress relief hole 103 is formed along the d-axis. This ensures that the stress on the reinforcing ribs between the first set of magnet grooves 21 does not exceed the material's yield strength, guaranteeing that it will not break during high-speed motor rotation.

[0198] Depend on Figures 38-40 It can be seen that the deformation at the position corresponding to the q-axis on the outer edge of the lamination body 10 is extremely small, causing stress concentration at the position corresponding to the d-axis on the outer edge of the lamination body 10. By opening a stress relief groove, a first stress relief hole 101 and a second stress relief hole 102 along the q-axis, and a third stress relief hole 103 along the d-axis, some stress is transferred to the d-axis. Therefore, a larger deformation occurs around the first stress relief hole 101 and the second stress relief hole 102, thereby alleviating the stress concentration of the large first magnetic isolation bridge and the second magnetic isolation bridge.

[0199] The specific principle described above is as follows: The second stress relief hole 102 can significantly reduce the weight of the lamination body 10, thereby reducing the internal stress of the lamination body 10 and effectively improving the stress distribution on the reinforcing rib between the two first magnet slots 211. At this time, the stress will be concentrated in the position of the first set of magnet slots 21 near the center of the lamination body 10. Furthermore, the first stress relief hole 101 is opened next to the reinforcing rib between the two first magnet slots 211. The first stress relief hole 101 can also reduce the weight of the lamination body 10 and effectively release the stress in the position of the first set of magnet slots 21 near the center of the lamination body 10.

[0200] In this embodiment, a stress relief groove is provided on the q-axis to ensure that the stress of the first magnetic isolation bridge 101a and the second magnetic isolation bridge 102a does not exceed the yield strength of the material, thus ensuring that they will not break when the motor rotates at high speed.

[0201] The stress relief groove in this embodiment disperses the stress on the outer edge of the lamination body 10 corresponding to the q-axis to the d-axis, thereby greatly improving the structural strength of the lamination body 10. While reducing the size of the magnetic bridge and reinforcing ribs, it can increase the rotor speed.

[0202] In some embodiments, the rotor lamination 100 further includes a sheath 60, which is sleeved around the periphery of the rotor lamination 100. The material of the sheath 60 includes, but is not limited to, plastic, metal, carbon fiber, etc. The sheath 60 can be wrapped around the periphery of the rotor lamination 100 under high-strength tension. The sheath 60 and the rotor lamination 100 can also be assembled using press-fitting or winding processes to obtain a certain preload. The preload will effectively counteract the centrifugal force on the reinforcing ribs at high speeds, thereby breaking through the original speed limit and facilitating the achievement of ultra-high speeds of 30,000 rpm.

[0203] However, under the centrifugal force of ultra-high speed operation or the pressure of high temperature operation, the magnetic bridge and reinforcing ribs of the rotor lamination 100 are subjected to radially outward tensile stress. At the same time, the rotor lamination 100 is also subjected to radially inward compressive stress applied by the sheath 60. Significant stress concentrations occur at the magnetic bridge and reinforcing ribs of the rotor lamination 100. If the tensile or compressive stress in these areas exceeds the allowable stress of the lamination body material 10 after prolonged exposure to this cyclic tensile-compressive stress, the rotor core may fracture and fail. Therefore, the rotor lamination 100 needs to be able to withstand both tensile and compressive stresses simultaneously.

[0204] To solve the above problems, Figure 41 Clearly identify the locations in the rotor where stress is concentrated. Figure 41 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application.

[0205] These are: two first magnetic isolation bridges 101a located at both ends of the first group of magnetic steel grooves 21, two first reinforcing ribs 31 and one second reinforcing rib 32 located inside the first group of magnetic steel grooves 21, two second magnetic isolation bridges 102a located at both ends of the second group of magnetic steel grooves 22, two third reinforcing ribs 33 located inside the second group of magnetic steel grooves, and two parts of the stamped body (hereinafter referred to as the first support arm 103a) located between the first magnetic steel groove and the third magnetic steel groove.

[0206] Because the area of ​​the first set of magnet slots 21 in the motor rotor is relatively large, the stress concentration problem at the two first magnetic isolation bridges 101a, the two first reinforcing ribs 31, and the one second reinforcing rib 32 is quite serious during ultra-high speed rotation. Under high-temperature conditions, the two third reinforcing ribs 33 and the two first support arms 103a related to the second set of magnet slots 22 are more likely to exceed the material strength limit. Furthermore, the two first reinforcing ribs 31 also experience localized stress distortion, and are quite sensitive to the dimensions of the two first magnetic isolation bridges 101a and the two second magnetic isolation bridges 102a. The following focuses on optimizing the stress of the first magnetic isolation bridge 101a, the second magnetic isolation bridge 102a, the first reinforcing rib 31, the second reinforcing rib 32, and the third reinforcing rib 33.

[0207] First, this application employs a double-U topology in the rotor lamination 100, incorporating multiple reinforcing ribs to withstand centrifugal forces or pressures on the rotor laminations. The reinforcing ribs exhibit a progressively decreasing skeletal structure along the d-axis, decreasing from three ribs between the first set of magnet slots 21 to two ribs between the second set of magnet slots 22. This allows for the accommodation of more magnets while reducing radial deformation of the rotor laminations and improving overall rigidity. This prevents centrifugal forces or pressures from concentrating on any single reinforcing rib, enabling the rotor to withstand greater centrifugal forces or pressures. Furthermore, the reduction in centrifugal forces or pressures on the reinforcing ribs allows for a reduction in the thickness of the sheath 60, reinforcing ribs, and magnetic bridge, thereby increasing the air gap magnetic flux density and ultimately improving the motor's torque and power density.

[0208] Secondly, this application provides a third stress relief hole 103 on the side of the second set of magnetic steel grooves 22 opposite to the first set of magnetic steel grooves 21, which can simultaneously reduce the stress level of each reinforcing rib and magnetic isolation bridge under centrifugal force. There are two third stress relief holes 103, which are symmetrically distributed along the d-axis and are bullet-shaped. The third stress relief holes 103 are surrounded by smooth contour lines.

[0209] Then, this application provides a first stress buffer groove 104a and a second stress buffer groove 105a on both sides of the two first reinforcing ribs 31, extending the stress of the two first reinforcing ribs 31 outward to reduce stress concentration under tension and compression. The outlines of the first stress buffer groove 104a and the second stress buffer groove 105a can be fishhook-shaped and are approximately centrally symmetrical with respect to the first reinforcing ribs 31. Furthermore, the presence of the second stress buffer groove 105a can divert more of the centrifugal force of the magnet in the second magnet groove 212 to the second reinforcing rib 32, so as to distribute the stress evenly.

[0210] Furthermore, this application provides a third stress buffer groove 106a and a fourth stress buffer groove 107a at both ends of the two first magnetic isolation bridges 101a, and a fifth stress buffer groove 108a and a sixth stress buffer groove 109a at both ends of the two second magnetic isolation bridges 102a, which can extend the length of the two first magnetic isolation bridges 101a and the two second magnetic isolation bridges 102a in order to disperse the stress concentration caused by centrifugal force.

[0211] It should be noted that the third stress buffer groove 106a, the fourth stress buffer groove 107a, the fifth stress buffer groove 108a and the sixth stress buffer groove 109a reduce the local stiffness at their respective locations, thereby weakening the pressure transmitted to the two first reinforcing ribs 31, the second reinforcing ribs 32 and the two third reinforcing ribs 33.

[0212] In addition, this application also provides a seventh stress buffer groove 110a, an eighth stress buffer groove 111a and a ninth stress buffer groove 112a on the two third reinforcing ribs 33, the two first reinforcing ribs 31 and the second reinforcing rib 32 respectively, which are composed of arcs with large radii of curvature and continuous tangency, which can further reduce local stress concentration under pressure.

[0213] Finally, this application provides grooves 113a on the two first support arms 103a, which can disperse the localized stress caused by pressure over a longer area. The bottom edge of the groove 113a is basically parallel to the extension direction of the first magnet groove 211, ensuring that the centrifugal force of the magnets in the first set of magnet grooves 21 and the pre-tightening force of the sheath 60 are evenly distributed at the bottom of the groove. The groove 113a can be roughly trapezoidal, with a bottom width greater than or equal to 0.8 mm and less than or equal to 1.5 mm, and a width greater than or equal to 3 mm and less than or equal to 6 mm. If the width of the groove 113a is too small, the stress dispersion will not be uniform enough; if the width of the groove 113a is too large, it will increase the magnetic circuit resistance and affect the motor power output. When the width of the groove 113a is within this range, both the uniformity of stress distribution and the power of the motor can be taken into account.

[0214] In some embodiments, the angle of the first set of magnet slots 21 can be greater than or equal to 70° and less than or equal to 90°, and the angle of the second set of magnet slots 22 can be greater than or equal to 110° and less than or equal to 120°. A larger angle of the magnet slots is beneficial for increasing the amount of permanent magnets used, while a smaller angle of the magnet slots is beneficial for improving the rotor's magnetization effect and the utilization rate of permanent magnets. When the angles of the first set of magnet slots 21 and the second set of magnet slots 22 are within this range, both the amount of permanent magnets used and the utilization rate of permanent magnets can be considered simultaneously.

[0215] In some embodiments, the distance from the bottom of the groove 113a to the first set of magnet grooves 21 is equal to the thickness of the first support arm 103a. In some embodiments, the minimum thickness w of the first support arm 103a is ≥ 3mm. This ensures the structural strength of the lamination body.

[0216] In some embodiments, the sixth stress buffer groove 109a connects the first set of magnetic grooves 21 and the second magnetic isolation bridge 102a, reducing the stiffness level at that location to decrease the pressure transmitted to the groove 113a. The sixth stress buffer groove 109a is composed of a smooth arc with a small radius of curvature, and the hole depth does not exceed the radius line tangent to the groove 113a, thus preventing stress distortion when subjected to pressure at this location.

[0217] like Figure 42 and Figure 43 As shown, Figure 42 The stress diagram is for a static state. Figure 43The stress diagram shows that the stress is below 430MPa in both static and high-speed states, successfully achieving an ultra-high motor speed of 30,000rpm.

[0218] This patent proposes a rotor structure suitable for reducing eddy current losses, which is a double U-shaped 6-pole rotor. For example... Figure 44 As shown, Figure 44 This is a partial structural schematic diagram of another rotor lamination provided in an embodiment of this application. Typically, the central axis of the rotor magnetic poles is defined as the d-axis, while... Figure 1 The axis that differs from the d-axis by a mechanical angle of 30° is defined as the q-axis. Since the electrical angle is several times the mechanical angle of a pole pair, this patent contains 6 rotor poles and 3 pole pairs. The electrical angle is 3 times the mechanical angle. According to the concept of electrical angle, the d-axis and q-axis differ by a 90° electrical angle.

[0219] like Figure 45 As shown, Figure 45 This is a schematic diagram of a magnet provided in an embodiment of this application. The armature magnetic field generated by the higher harmonics of the stator current forms eddy currents on the surface of the magnet, thereby generating eddy current losses in the magnet, which are positively correlated with magnetic flux density, length and conductivity.

[0220] like Figures 46-48 As shown, Figure 46 The magnetic force distribution diagram is given when an alternating current Id is applied to the three-phase winding of the sub-electrode. Figure 47 The magnetic force distribution diagram is given when an alternating current of Id = Iq is applied to the three-phase winding of the sub-branch. Figure 48 To obtain the magnetic force distribution diagram of the stator three-phase windings when an alternating current Iq is applied, the magnets are attached to air. With only the stator three-phase windings energized with alternating current, the flow path of the magnetic field emanating from the stator turns on the rotor is observed under three different input currents: Id only, Id = Iq, and Iq only. It is found that the magnetic field lines are more concentrated along the q-axis, therefore, the closer the magnets are to the q-axis, the greater the eddy current losses. The more magnet units that form the magnets closer to the q-axis, the more significantly the eddy current losses can be reduced.

[0221] Based on this, such as Figure 44 As shown, in some embodiments, the magnets 50 in the first magnet slot 211 include a plurality of magnet units arranged along the extension direction of the first magnet slot, and the magnets in the second magnet slot 212 include a plurality of magnet units arranged along the extension direction of the second magnet slot 212. The arrangement density of the magnet units in the first magnet slot 211 is greater than the arrangement density of the magnet units in the second magnet slot 212. This can reduce the eddy current losses of the magnets near the q-axis in the first set of magnet slots 21.

[0222] Similarly, in some embodiments, in the second set of magnet slots 22, the magnets in the third magnet slot 221 include multiple magnet units arranged along the extension direction of the third magnet slot 221, and the magnets in the fourth magnet slot 222 include multiple magnet units arranged along the extension direction of the fourth magnet slot 222. The arrangement density of the magnet units in the third magnet slot 221 is greater than that in the fourth magnet slot 222. This can reduce the eddy current losses of the magnets near the q-axis in the second set of magnet slots 22.

[0223] like Figures 49 to 51 As shown, Figure 49 The image shows the eddy current loss contour plots, divided into two segments radially near the d-axis and two segments radially near the q-axis. Figure 50 The image shows the eddy current loss contour plots, divided into two segments radially near the d-axis and four segments radially near the q-axis. Figure 51 The simulation results for eddy current loss are shown in the figure. The eddy current loss when the eddy current is divided into four segments near the q-axis is significantly less than that when the eddy current is divided into two segments near the q-axis. The loss is reduced by 55% at high speed, which is consistent with the theory.

[0224] The rotor structure proposed in this patent is suitable not only for motors with 6 poles, but also for drive motors with 8, 10 and 12 poles. It is not only suitable for double U-shaped magnet arrangements, but also for magnet structures with single V-shaped, triangular and U-shaped arrangements.

[0225] In some embodiments, the no-load air gap magnetic flux density of the motor is greater than 0.7T and less than or equal to 0.9T. Alternatively, the no-load air gap magnetic flux density of the motor is greater than 0.75T and less than or equal to 0.85T. Alternatively, the no-load air gap magnetic flux density of the motor is greater than 0.78T and less than or equal to 0.82T.

[0226] In some embodiments, the number of stators is multiple. The multiple stators are arranged in a row. At least one rotor is provided between two adjacent stators, and the extension direction of the shaft of the at least one rotor is consistent with the arrangement direction of the multiple stators.

[0227] In some embodiments, the number of rotors is multiple. The multiple rotors are coaxially arranged and aligned along the extension direction of the shaft. At least one stator is provided between two adjacent rotors.

[0228] In some embodiments, each pole and each phase slot of the motor is an integer greater than or equal to 1.

[0229] This application also provides a powertrain, which includes the motor described in any of the above embodiments.

[0230] In some embodiments, the powertrain may further include a transmission, with the motor connected to the transmission via a shaft.

[0231] In the description of the embodiments of this application, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0232] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A rotor lamination, used in a motor, characterized in that, include: Film processing body; Multiple magnet mounting parts are disposed on the lamination body and arranged circumferentially along the lamination body. The magnet mounting parts include a first set of magnet slots and a second set of magnet slots. The second set of magnet slots is located on the side of the first set of magnet slots away from the center of the lamination body. The first set of magnet slots includes a first magnet slot and a second magnet slot. There are two first magnet slots, which are spaced apart circumferentially. The second magnet slot is located between the two first magnet slots. The second set of magnetic steel grooves includes a third magnetic steel groove and a fourth magnetic steel groove. There are two third magnetic steel grooves, which are spaced apart circumferentially, and the fourth magnetic steel groove is disposed between the two third magnetic steel grooves.

2. The rotor lamination according to claim 1, characterized in that, The opening angle α1 of the first group of magnet slots satisfies: 2.1×α01≤α1≤2.5×α01; the opening angle α2 of the second group of magnet slots satisfies: 5.5×α02≤α2≤5.9×α02; Wherein, α01 is the polar arc angle of the first group of magnet slots, and α02 is the polar arc angle of the second group of magnet slots.

3. The rotor lamination according to claim 2, characterized in that, The two first magnet slots extend from one end to the other toward the center of the lamination body and tilt toward each other, and the included angle between the two first magnet slots forms the opening angle α1.

4. The rotor lamination according to claim 3, characterized in that, The second magnet slot is located between the two first magnet slots at one end facing the center of the lamination body.

5. The rotor lamination according to claim 4, characterized in that, The number of second magnet slots is multiple, and multiple second magnet slots are arranged sequentially along the arrangement direction of the two first magnet slots towards the center of the lamination body.

6. The rotor lamination according to claim 5, characterized in that, The two third magnet grooves extend from one end to the other toward the center of the lamination body and tilt toward each other, and the included angle between the two third magnet grooves forms the opening angle α2.

7. The rotor lamination according to claim 6, characterized in that, The fourth magnet slot is located between the two third magnet slots at one end facing the center of the lamination body.

8. The rotor lamination according to claim 7, characterized in that, The portion of the lamination body located between the first magnet groove and the adjacent second magnet groove forms a first reinforcing rib; the portion of the lamination body located between two adjacent second magnet grooves forms a second reinforcing rib; and the portion of the lamination body located between the third magnet groove and the adjacent fourth magnet groove forms a third reinforcing rib. Along the circumference of the lamination body, the first reinforcing rib and the third reinforcing rib, as well as the second reinforcing rib and the third reinforcing rib, are arranged in a staggered manner.

9. The rotor lamination according to claim 5, characterized in that, The portion of the lamination body located between the first magnet groove and the adjacent second magnet groove forms a first reinforcing rib, and the portion of the lamination body located between two adjacent second magnet grooves forms a second reinforcing rib. Along the arrangement direction of the first magnet groove and the adjacent second magnet groove, the size of the first reinforcing rib is a1, and the size of the second reinforcing rib is a2. The size of a1 and the size of a2 satisfy: 1.2mm≤a1≤1.8mm, 1.2mm≤a2≤1.8mm.

10. The rotor lamination according to claim 9, characterized in that, The a1 and a2 also satisfy the condition: 3.7mm≤(a1+a2×2)≤4.8mm.

11. The rotor lamination according to claim 9, characterized in that, The dimension of the first reinforcing rib along the arrangement direction perpendicular to the first magnet slot and the adjacent second magnet slot is K1, and the dimension of the second reinforcing rib along the arrangement direction of two adjacent second magnet slots is K2. K1 and a1 satisfy: 4.8≤K1 / a1≤10.2, and / or K2 and a2 satisfy: 4.8≤K2 / a2≤10.

2.

12. The rotor lamination according to claim 6, characterized in that, The portion of the lamination body located between the third magnet groove and the adjacent fourth magnet groove forms a third reinforcing rib; the dimension of the third reinforcing rib is a3 along the arrangement direction of the third magnet groove and the adjacent fourth magnet groove; the dimension of the third reinforcing rib along the arrangement direction perpendicular to the third magnet groove and the adjacent fourth magnet groove is K3; a3 and K3 satisfy: 5.2≤K3 / a3≤7.

4.

13. The rotor lamination according to claim 5, characterized in that, The dimension L1 of the first magnet groove in the extension direction satisfies: 7.2mm≤L1≤9.1mm, and the dimension L2 of the second magnet groove in the extension direction satisfies: 16.5mm≤L2≤18.4mm.

14. The rotor lamination according to claim 5, characterized in that, The dimension W1 of the first magnet groove perpendicular to the extension direction satisfies: 7mm≤W1≤7.6mm, and the dimension W2 of the second magnet groove perpendicular to the extension direction satisfies: 7mm≤W2≤7.6mm.

15. The rotor lamination according to claim 1, characterized in that, The lamination body is provided with mounting holes, and the plurality of magnet mounting parts are located around the mounting holes and arranged circumferentially along the mounting holes; The distance from the first set of magnet slots to the mounting hole is d1, and the distance from the outer edge of the lamination body to the mounting hole is d2. The d1 and d2 satisfy: 0.4≤d1 / d2≤0.

61.

16. The rotor lamination according to claim 3, characterized in that, The included angle region between the two first magnet slots is the first region; The lamination body is also provided with a first stress relief hole, which is located on the side of the first magnet groove opposite to the first region.

17. The rotor lamination according to claim 16, characterized in that, The distance from the geometric center of the first stress relief hole to the center of the lamination body is R2; the lamination body is circular, and the radius of the lamination body is R1, wherein R1 and R2 satisfy: 0.55≤R2 / R1≤0.65; The two first magnetic grooves are symmetrically arranged about a first axis passing through the center of the lamination body. The line connecting the geometric center of the first stress relief hole and the center of the lamination body is the second axis. The angle θ1 between the second axis and the first axis satisfies: 9°≤θ1≤13°.

18. The rotor lamination according to claim 16, characterized in that, The lamination body is also provided with a second stress relief hole, which is located on the side of the first stress relief hole opposite to the first magnet groove.

19. The rotor lamination according to claim 18, characterized in that, The distance from the geometric center of the second stress relief hole to the center of the lamination body is R3; the lamination body is circular, and the radius of the lamination body is R1, wherein R1 and R3 satisfy: 0.55≤R3 / R1≤0.65; The two first magnetic grooves are symmetrically arranged about a first axis passing through the center of the lamination body. The line connecting the geometric center of the second stress relief hole and the center of the lamination body is a third axis. The angle θ2 between the third axis and the first axis satisfies: (180° / P)-10°≤θ2≤180° / P.

20. The rotor lamination according to claim 6, characterized in that, The included angle region between the two third magnet slots is the second included angle region, and at least one third stress relief hole is provided in the second included angle region.

21. The rotor lamination according to claim 20, characterized in that, The portion of the lamination body located between the two third magnet slots forms a fourth reinforcing rib; at least a portion of the third stress relief hole is opposite to the fourth reinforcing rib along the radial direction of the lamination body. Alternatively, the fourth magnet groove is located between the two third magnet grooves at one end facing the center of the lamination body, and at least a portion of the third stress relief hole is opposite to the fourth magnet groove along the radial direction of the lamination body.

22. The rotor lamination according to claim 21, characterized in that, The two first magnetic grooves are symmetrically arranged about a first axis passing through the center of the lamination body. There are two third stress relief holes, which are located on opposite sides of the first axis and are symmetrically arranged about the first axis.

23. The rotor lamination according to claim 22, characterized in that, The distance between the two third stress relief holes is d3, and the distance from the geometric center of the third stress relief hole to the outer edge of the lamination body is d4; The condition d3 and d4 satisfy the following condition: 2.5 ≤ d4 / d3 ≤ 4.

24. The rotor lamination according to claim 22, characterized in that, The third stress relief hole has a circumferential dimension of L3 along the body of the lamination and a radial dimension of W3 along the body of the lamination; L3 and W3 satisfy: 1.4≤L3 / W3≤1.

8.

25. The rotor lamination according to claim 22, characterized in that, The distance d5 from the third stress relief hole to the outer edge of the lamination body satisfies: 0.9mm≤d5≤1.3mm.

26. The rotor lamination according to claim 3, characterized in that, The lamination body is also provided with a stress relief groove. Along the circumference of the lamination body, the stress relief groove is located between two adjacent magnet mounting parts, and the stress relief groove passes through the outer edge of the lamination body.

27. The rotor lamination according to claim 4, characterized in that, The lamination body is also provided with a fourth stress relief hole; along the circumference of the lamination body, the fourth stress relief hole is located between two adjacent magnet mounting parts, and the fourth stress relief hole is circumferentially closed. The two first magnet slots are symmetrically arranged about a first axis passing through the center of the lamination body; the fourth stress relief hole passes through a fourth axis, which passes through the center of the lamination body, and the included angle θ4 between the fourth axis and the first axis satisfies: θ4=180° / P.

28. The rotor lamination according to claim 27, characterized in that, The lamination body is provided with mounting holes, and the plurality of magnet mounting parts are located around the mounting holes and arranged circumferentially along the mounting holes; Along the extension direction of the first axis, the fourth stress relief hole is located between the second magnet groove and the mounting hole; along the extension direction of the first axis, the distance between the fourth stress relief hole and the second magnet groove is m1, the size of the fourth stress relief hole is m2, and the distance between the fourth stress relief hole and the mounting hole is m3; m1, m2, and m3 satisfy: m1:m2:m3=(3-3.5): (5-6): (7-8).

29. The rotor lamination according to claim 27, characterized in that, The portion of the fourth stress relief hole located between the fourth axis and the first axis includes a first inner sidewall and a second inner sidewall. The first inner sidewall and the second inner sidewall are arranged radially along the lamination body, and the included angle θ5 between the first inner sidewall and the second inner sidewall satisfies: 65°≤θ5≤70°.

30. The rotor lamination according to claim 1, characterized in that, The edges of at least one magnetic steel groove in the first group of magnetic steel grooves and the second group of magnetic steel grooves are provided with grooves that are recessed to the side away from the magnetic steel grooves. The included angle θ6 between at least one inner wall of the groove and the inner wall of the adjacent magnetic steel groove satisfies: 5°≤θ6≤8°.

31. A rotor, characterized in that, It includes a first set of magnets, a second set of magnets, and a rotor lamination as described in any one of claims 1-30, wherein the first set of magnets is housed in a first set of magnet slots, and the second set of magnets is housed in a second set of magnet slots.

32. The rotor according to claim 31, characterized in that, The magnets in each of the first set of magnet slots include multiple magnet units arranged along the extension direction of the magnet slot, or multiple magnet units arranged along the axial direction of the rotor lamination.

33. The rotor according to claim 32, characterized in that, The two first magnet slots extend from one end to the other toward the center of the lamination body and are inclined toward each other; the at least one second magnet slot is located between the ends of the two first magnet slots that are toward the center of the lamination body. The magnet in the first magnet slot includes a plurality of magnet units arranged along the extension direction of the first magnet slot, and the magnet in the second magnet slot includes a plurality of magnet units arranged along the extension direction of the second magnet slot. The arrangement density of the magnet units in the first magnet slot is greater than the arrangement density of the magnet units in the second magnet slot.

34. The rotor according to claim 31, characterized in that, The magnets in each of the second set of magnet slots include multiple magnet units arranged along the extension direction of the magnet slot, or multiple magnet units arranged along the axial direction of the rotor lamination.

35. The rotor according to claim 34, characterized in that, The two third magnet slots extend from one end to the other toward the center of the lamination body and are inclined toward each other; the at least one fourth magnet slot is located between the ends of the two third magnet slots that are toward the center of the lamination body. The magnets in the third magnet slot include multiple magnet units arranged along the extension direction of the third magnet slot, and the magnets in the fourth magnet slot include multiple magnet units arranged along the extension direction of the fourth magnet slot. The arrangement density of the magnet units in the third magnet slot is greater than the arrangement density of the magnet units in the fourth magnet slot.

36. An electric motor, characterized in that, Includes a stator and a rotor as described in any one of claims 31-35.

37. The motor according to claim 36, characterized in that, The no-load air gap magnetic flux density of the motor is greater than 0.7T and less than or equal to 0.9T; Alternatively, the no-load air gap magnetic flux density of the motor is greater than or equal to 0.75T and less than or equal to 0.85T; Alternatively, the no-load air gap magnetic flux density of the motor is greater than or equal to 0.78T and less than or equal to 0.82T.

38. A powertrain, characterized in that, Includes the motor described in claim 36 or 37.

39. A vehicle, characterized in that, Includes the powertrain as described in claim 38.

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