Rotor punching sheet, rotor assembly, motor, power assembly and vehicle

Abstract

The invention relates to a rotor punching sheet, a rotor assembly, a motor, a power assembly and a vehicle. One or more magnetic groove structures are formed in the rotor punching sheet, each magnetic groove structure comprises a first magnetic groove assembly and a second magnetic groove assembly which are arranged at intervals in the radial direction of the rotor punching sheet, the second magnetic groove assembly is located on the radial inner side of the first magnetic groove assembly, and the first magnetic groove assembly comprises a plurality of first magnetic grooves. The plurality of first magnetic slots have center lines extending along the arrangement direction of the first magnetic slots, and the included angle between the center lines of any two first magnetic slots is alpha; the second magnetic groove assembly comprises a plurality of second magnetic grooves, the second magnetic grooves are provided with center lines extending in the arrangement direction of the second magnetic grooves, and the included angle between the center lines of any two second magnetic grooves is beta; 0.75 < = alpha / beta < = 1.9. The invention aims to solve the technical problem that the operation efficiency of the motor is reduced due to magnetic leakage of the existing motor.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a rotor punching sheet, a rotor assembly, a motor powertrain, and a vehicle. Background Art

[0002] Thin strips (such as amorphous alloys) used in the stator and rotor cores of motors can effectively reduce the eddy current flow area and increase resistance, thereby reducing high-frequency eddy current losses. In the prior art, the rotor and stator of a motor are formed by stacking thin strips. The motor rotor and motor stator formed by stacking thin strips will have magnetic leakage, resulting in a decrease in the allowable efficiency of the motor. Summary of the invention

[0003] The present application provides a rotor punching, a rotor assembly, a motor, a powertrain and a vehicle, aiming to solve the technical problem that magnetic leakage exists in existing motors, resulting in reduced motor operating efficiency.

[0004] In order to achieve the above object, according to a first aspect of the present application, a rotor punching is provided, wherein the rotor punching is formed with one or more magnetic slot structures, each of the magnetic slot structures comprises a first magnetic slot assembly and a second magnetic slot assembly spaced apart in a radial direction of the rotor punching, wherein the second magnetic slot assembly is located radially inward of the first magnetic slot assembly, wherein:

[0005] The first magnetic slot assembly includes a plurality of first magnetic slots, the plurality of first magnetic slots have center lines extending along the arrangement direction of the first magnetic slots, and the angle between the center lines of any two first magnetic slots is α;

[0006] The second magnetic slot assembly includes a plurality of second magnetic slots, the plurality of second magnetic slots have a center line extending along an arrangement direction of the second magnetic slots, and an angle between the center lines of any two second magnetic slots is β;

[0007] 0.75≤α / β≤1.9.

[0008] Optionally, a contour line of a projection of each of the first magnetic slots on a cross section of the rotor punching sheet includes at least one first straight line segment, at least one of the first straight line segments includes a first sub-straight line segment with the longest length, and an angle between the first sub-straight line segments of any two of the first magnetic slots is α;

[0009] The contour line of the projection of each second magnetic slot on the cross section of the rotor punching includes at least one second straight line segment, at least one second straight line segment includes a second sub-straight line segment with the longest length, and the angle between the second sub-straight line segments of any two second magnetic slots is β;

[0010] Among them, 0.75≤α / β≤1.9.

[0011] Optionally, 1.03≤α / β≤1.89.

[0012] Optionally, the first magnetic slot assembly has a first symmetry line extending in the radial direction of the rotor sheet, and the plurality of first magnetic slots are arranged in an axisymmetric manner along the first symmetry line;

[0013] The second magnetic slot assembly has a second symmetry line extending in the radial direction of the rotor sheet, and a plurality of the second magnetic slots are arranged in an axisymmetric manner along the second symmetry line.

[0014] Optionally, the second magnetic slot assembly has a second symmetry line extending in the radial direction of the rotor punching sheet, and a plurality of the second magnetic slots form two magnetic slot groups symmetrically distributed along the second symmetry line. In the same magnetic slot group, the second sub-straight line segment of the second magnetic slot closer to the second symmetry line has a larger angle with the second symmetry line.

[0015] Optionally, the minimum distance between two adjacent first magnetic grooves is L1, L1 ≥ 0.5 mm; and / or,

[0016] The minimum distance between two adjacent second magnetic grooves is L2, and L2≥0.5 mm.

[0017] Optionally, in the rotor punching, the number of the magnetic slot structures is n1, the sum of the number of the first magnetic slots and the second magnetic slots of each magnetic slot structure is n2, and 0.66≤n1 / n2≤7.

[0018] Optionally, the minimum distance between the first magnetic groove and the second magnetic groove is L3, the outer arc length of the rotor punching is L4, and L3 / L4≥0.05.

[0019] Optionally, the shortest distance between two adjacent magnetic groove structures is H1, and H1≥1 mm.

[0020] According to a second aspect of the present application, a rotor assembly is provided, wherein the rotor assembly is formed by stacking the above-mentioned rotor sheets.

[0021] According to a second aspect of the present application, there is provided a motor, comprising:

[0022] a housing, wherein a stator assembly is disposed on the housing; and

[0023] The motor shaft is at least partially rotatably mounted in the housing, and a rotor assembly is provided on the motor shaft, and the rotor assembly is the above-mentioned rotor assembly.

[0024] Optionally, the stator assembly includes a stator core, and the stator core includes a plurality of stacked stator punching sheets.

[0025] Optionally, the stator punching sheet includes a connected yoke portion and a tooth portion, the yoke portion is located on the outside of the stator punching sheet, and the tooth portion is located close to the inside of the stator punching sheet, the radial length of the yoke portion is he, and the radial length of the tooth portion is hc, 0.95≤hc / he≤1.52.

[0026] Optionally, 1.1≤hc / he≤1.4.

[0027] Optionally, the tooth portion includes a plurality of stator teeth, and the plurality of stator teeth are spaced apart on the yoke portion, each of the stator teeth includes a connected tooth end and a tooth shoulder, the tooth end is connected to the yoke portion, and the width of the tooth shoulder is greater than the width of the tooth end.

[0028] Optionally, at least one of the tooth shoulders is provided with grooves along two radially opposite sides thereof.

[0029] Optionally, each tooth shoulder is provided with a groove.

[0030] Optionally, the plurality of tooth shoulders provided with the grooves form a plurality of tooth shoulder groups, each tooth shoulder group includes two tooth shoulders, and at least one tooth shoulder without the groove is provided between the two tooth shoulders.

[0031] Optionally, the number of the tooth shoulders without the grooves between the two tooth shoulders of each tooth shoulder group is the same; or,

[0032] The number of the tooth shoulders without the grooves between the two tooth shoulders of at least one tooth shoulder group is different from the number of the tooth shoulders without the grooves between the two tooth shoulders of another tooth shoulder group.

[0033] Optionally, in the same tooth shoulder (215), the maximum dimension of the groove (216) in the radial direction of the stator core (21) is D1, and the dimension of the tooth shoulder (215) in the radial direction of the stator core (21) is D2, and 0.05≤D1 / D2≤0.2.

[0034] Optionally, the thickness of each stator punching sheet is Ls, the outer diameter of each stator punching sheet is Ds, and 0.19‰≤Ls / Ds≤1.68‰.

[0035] Optionally, the thickness of each of the rotor punching sheets is Ls2, the outer diameter of the rotor punching sheets without the rotor punching sheets is Ls2, and 0.35‰≤Ls2 / Ds2≤2.46‰.

[0036] Optionally, the stator core further includes two stator cover plates, and the two stator cover plates are fixed at two ends of the stator core that are oppositely arranged along the axial direction.

[0037] According to a third aspect of the present application, a power assembly is also provided, comprising the above-mentioned motor.

[0038] According to a fourth aspect of the present application, a vehicle is also provided, comprising the above-mentioned powertrain.

[0039] The rotor punching structure provided in the present application has strong strength and low cost, and can support high-speed operation of the motor. A plurality of first magnetic grooves and second magnetic grooves are provided on the rotor punching. The angle between the first sub-straight segments of any two first magnetic grooves is α, and the angle between the second sub-straight segments of any two second magnetic grooves is β. 0.75≤α / β≤1.9. Within the above range, the area of ​​the local saturation region of the rotor punching can be reduced, so that the motor can operate under rated conditions and full load conditions, thereby improving the working efficiency of the motor.

[0040] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0042] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same figure numbers represent the same parts in the following description.

[0043] Figure 1 It is a structural schematic diagram of an embodiment of a rotor punching provided by the present application;

[0044] Figure 2 yes Figure 1 A magnified schematic diagram of D in the middle;

[0045] Figure 3 is a schematic diagram of the relationship between α / β and stress;

[0046] Figure 4 is a schematic diagram of the relationship between the first connection portion and the output torque;

[0047] Figure 5 It is the relationship between L3 / L4 and motor performance;

[0048] Figure 6 It is the BH curve diagram of silicon steel and amorphous alloy;

[0049] Figure 7 This is the torque-current comparison diagram of the motor at a speed of 3000 rpm;

[0050] Figure 8 This is the torque-current comparison diagram of the motor at a speed of 5000rpm;

[0051] Fig. 9 It is the magnetic flux distribution diagram of the motor;

[0052] Fig.10 It is the BH curve of amorphous alloy;

[0053] Fig.11 It is the analytical model of the motor’s magnetic circuit;

[0054] Fig.12 This is a comparison chart of the tensile strength of amorphous alloys and silicon steel alloys;

[0055] Fig.13 It is a schematic diagram of the effect of the magnetic slot factor on the limiting speed and output torque;

[0056] Fig.14 This is a simplified diagram of the process of forming amorphous alloy thin strips;

[0057] Fig.15 It is a schematic diagram of the atomic arrangement of silicon steel;

[0058] Fig.16 It is a schematic diagram of the arrangement of atoms in an amorphous alloy;

[0059] Fig.17 It is a schematic diagram that represents the process of metal from molten state to crystalline state;

[0060] Fig.18 It is a comparison chart of the tensile strength of materials under different processing conditions;

[0061] Fig.19 It is a schematic diagram of the tearing process of amorphous alloy ribbon;

[0062] Fig. 20 It is a schematic diagram of the effect of pole number on stress;

[0063] Fig.21 It is a schematic diagram of the influence of pole number on peak torque and working efficiency;

[0064] Fig. 22 It is a schematic diagram of the influence of the width of the first connecting part and the second connecting part on power and efficiency.

[0065] Fig.23 is a structural schematic diagram of an embodiment of a stator assembly provided by the present application;

[0066] Fig.24 yes Fig.23 Schematic diagram of the structure of the middle stator punching sheet;

[0067] Fig.25yes Fig.24 A magnified schematic diagram of B;

[0068] Fig.26 yes Fig.25 A magnified schematic diagram of middle C;

[0069] Fig. 27 It is a schematic diagram of the effect of hc / he on the output torque;

[0070] Fig.28 It is a schematic diagram comparing the magnetic permeability curves of amorphous alloy and silicon steel;

[0071] Fig.29 is a schematic diagram of the magnetic circuit of the stator assembly;

[0072] Fig.30 It is a schematic diagram of the iron loss distribution outside the protection range of the gear-yoke ratio;

[0073] Fig.31 It is a schematic diagram of the iron loss distribution within the protection range of the gear-yoke ratio;

[0074] Fig.32 It is a schematic diagram comparing hc / he and motor efficiency;

[0075] Fig.33 yes Fig.26 Middle E is an enlarged schematic diagram;

[0076] Fig.34 The invention discloses a preparation process of an embodiment of composite rolling of amorphous alloy thin strips;

[0077] Fig.35 This is another embodiment of the preparation process of composite rolling of amorphous alloy thin strips;

[0078] Fig.36 The influence of the stacking diameter ratio of the rotor punching sheets on the yield rate.

[0079] Description of reference numerals:

[0080] 100, rotor punching; 1, magnetic slot structure; 11, first magnetic slot assembly; 111, first magnetic slot; 112, first connecting portion; 12, second magnetic slot assembly; 121, second magnetic slot; 122, second connecting portion;

[0081] 200, stator assembly; 21, stator core; 210, stator punching sheet; 211, yoke; 212, tooth portion; 213, stator tooth; 214, tooth end; 215, tooth shoulder; 216, groove; 22, stator cover plate;

[0082] 31. molten amorphous alloy; 32. nozzle; 33. roller; 34. amorphous alloy thin strip;

[0083] 41. First dividing line; 42. Second dividing line; 43. Third dividing line. DETAILED DESCRIPTION

[0084] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0085] Thin strips (such as amorphous alloys) used in the stator and rotor cores of motors can effectively reduce the eddy current flow area and increase resistance, thereby reducing high-frequency eddy current losses. In the prior art, the rotor and stator of a motor are formed by stacking thin strips. The motor rotor and motor stator formed by stacking thin strips will have magnetic leakage, resulting in a decrease in the allowable efficiency of the motor.

[0086] In view of this, the present application proposes a motor. Figures 1 to 32 This is a structural schematic diagram of an embodiment of a motor provided in the present application. The motor provided in the present application has a low probability of magnetic leakage and high working efficiency. The motor will be described in detail below in conjunction with the main drawings.

[0087] The present application provides a motor, which includes a housing and a motor shaft. The housing is provided with a stator assembly 200. The motor shaft is rotatably installed in the housing, and the motor shaft is provided with a rotor assembly.

[0088] In some embodiments, the rotor assembly is formed by stacking multiple rotor sheets 100, and the stator assembly 200 includes a stator core 21 and a stator cover plate 22. The stator cover plate 22 is fixed to two ends of the stator core 21 that are oppositely arranged along its axial direction. The stator core 21 includes multiple stacked stator sheets 210.

[0089] The present application also provides a rotor punching sheet 100, see Figure 1 and Figure 2 The rotor punching 100 is formed with one or more magnetic slot structures 1, each magnetic slot structure 1 includes a first magnetic slot assembly 11 and a second magnetic slot assembly 12 arranged at intervals along the radial direction of the rotor punching 100, the second magnetic slot assembly 12 is located on the radial inner side of the first magnetic slot assembly 11, the first magnetic slot assembly 11 includes a plurality of first magnetic slots 111, the plurality of first magnetic slots 111 have center lines extending along the arrangement direction of the first magnetic slots 111, and the angle between the center lines of any two first magnetic slots 111 is α; the second magnetic slot assembly 12 includes a plurality of second magnetic slots 121, the plurality of second magnetic slots 121 have center lines extending along the arrangement direction of the second magnetic slots 121, and the angle between the center lines of any two second magnetic slots 121 is β; 0.75≤α / β≤1.9.

[0090] It should be noted that, in some embodiments, the first magnetic groove 111 and the second magnetic groove 121 are irregular shapes, and the first magnetic groove 111 and the second magnetic groove 121 are used to accommodate magnetic steel, and the magnetic steel has a center line (the center line is a line that divides the magnetic steel equally). When the magnetic steel is placed in the first magnetic groove 111 and the second magnetic groove 121, the center line of the magnetic steel will divide the first magnetic groove 111 and the second magnetic groove 121 equally, and the dividing line that divides the first magnetic groove 111 and the second magnetic groove 121 equally is the center line of the first magnetic groove and the second magnetic groove. In some other embodiments, the first magnetic groove 111 and the second magnetic groove 121 are regular shapes (such as rectangles, rectangles, etc.), and the center line of the first magnetic groove 111 and the second magnetic groove 121 is the dividing line. Further, in some embodiments, when the magnetic steel is a regular shape, such as a rectangle, the magnetic steel has two installation methods. The first is that the extension direction of the long side of the magnetic steel is the arrangement direction of the second magnetic groove 121, and the center line of the magnetic steel is the center line of the magnetic steel extending along the length direction. The second way is that the extension direction of the short side of the magnetic steel is the arrangement direction of the second magnetic slots 121, and the center line of the magnetic steel is the center line of the magnetic steel extending along the width direction. In other embodiments, when the shape of the magnetic steel is irregular, for example, when the magnetic steel includes a circle or a semi-circle, the center line of the magnetic steel is also an arc, and the angle between the centers of the two arcs is the angle between the tangents of the two arcs at one end close to each other.

[0091] In some other embodiments, the first magnetic slot assembly 11 includes a plurality of first magnetic slots 111, and the contour line of the projection of each first magnetic slot 111 on the cross section of the rotor punching 100 includes at least one first straight line segment, at least one first straight line segment includes a first sub-straight line segment with the longest length, and the angle between the first sub-straight line segments of any two first magnetic slots 111 is α; the second magnetic slot assembly 12 is located on the side of the first magnetic slot assembly 11 close to the center line of the rotor punching 100, and the second magnetic slot assembly 12 includes a plurality of second magnetic slots 121, and the contour line of the projection of each second magnetic slot 121 on the cross section of the rotor punching 100 includes at least one second straight line segment, at least one second straight line segment includes a second sub-straight line segment with the longest length, and the angle between the second sub-straight line segments of any two second magnetic slots 121 is β, 0.75≤α / β≤1.9.

[0092] The rotor punching 100 provided in the present application has a strong structural strength and a low cost, and can support the high-speed operation of the motor. A plurality of first magnetic slots 111 and second magnetic slots 121 are provided on the rotor punching 100. The angle between the first sub-straight segments of any two first magnetic slots 111 is α, and the angle between the second sub-straight segments of any two second magnetic slots 121 is β, and 0.75≤α / β≤1.9. Within the above range, the area of ​​the local saturation region of the rotor punching 100 can be reduced, so that the motor can operate under rated conditions and full load conditions, thereby improving the working efficiency of the motor.

[0093] It should be noted that the main materials of the rotor punching 100 are silicon steel and amorphous alloy. In this embodiment, the material of the rotor punching 100 is mainly amorphous alloy. The amorphous alloy material is applied to the rotor punching 100, which can effectively reduce the eddy current flow area, increase the resistance, and thus reduce the high-frequency eddy current loss.

[0094] Figure 3 is a schematic diagram of the relationship between α / β and stress, Figure 4 is a schematic diagram showing the relationship between the minimum distance between the first magnetic groove 111 and the second magnetic groove and the output torque, Figure 5 This is the relationship between L3 / L4 and motor performance.

[0095] In some embodiments, L3 / L4 should be greater than or equal to 0.05; the shortest distance between the two magnetic slot structures 1 is H1, which needs to be greater than or equal to 1mm, so that the motor can operate under rated conditions and full load conditions, and the local magnetic density of the amorphous rotor does not exceed 1.8T, ensuring that the motor does not deteriorate due to saturation, and ensuring that the high-frequency loss of the motor is as small as possible during high-speed operation. When the rotor design limit linear speed is greater than or equal to 160m / s, the minimum distance between two adjacent first magnetic slots 111 is L1, and the minimum distance between two adjacent second magnetic slots 121 is L2, L1 and L2 are greater than or equal to 0.5mm, and at the same time, in order to reduce local stress, α / β should be between 1.03 and 1.89.

[0096] It should be noted that, in this embodiment, please refer to Figure 2 The two adjacent first magnetic grooves 111 are respectively the first magnetic groove 111a1 and the first magnetic groove 111a2. The first magnetic groove 111a1 has a first point closest to the first magnetic groove 111a2, and the first magnetic groove 111a2 has a second point closest to the first magnetic groove 111a1. The first dimension line is drawn with the first point as the starting point, and the second dimension line is drawn with the second point as the starting point. The vertical distance between the first dimension line and the second dimension line is L1. The value selection method of L2 and H1 is the same as that of L1. You can refer to L1 and will not repeat them here.

[0097] Amorphous alloys have advantages such as low loss and good mechanical strength, but they also have problems such as low saturation magnetic density. Taking amorphous alloys and silicon steel as examples, Figure 6 The BH curve of silicon steel and amorphous alloy is shown in Figure 2. Figure 6 It can be concluded that compared with silicon steel, the magnetic permeability of amorphous alloys is close to that of air when the magnetic flux density is within the range of 1.5 to 1.6 T, that is, its saturation magnetic flux density is very low. During the operation of the motor, the torque component consists of two parts, namely:

[0098] T∝pψi q (L d -L q )i d i q(1)

[0099] L=N 2 μ(A / l) (2)

[0100] In the above formula, μ is the magnetic permeability of the magnetic circuit. When the saturation degree of the magnetic flux density of the motor is low, μ is high, and when the saturation degree of the magnetic flux density of the motor is high, μ is low.

[0101] Formula (1) is the permanent magnet torque, and formula (2) is the reluctance torque. When the motor is running at a high load stage, the saturation degree of the motor's magnetic flux density increases, while the magnetic permeability μ decreases, resulting in a deterioration in the output torque.

[0102] Compared with silicon steel, the magnetic permeability of amorphous alloys begins to deteriorate significantly when the magnetic flux density is above 0.8T. At the same time, due to the decrease in its saturation magnetic flux density, amorphous alloys require a larger current at medium and high loads to compensate for the torque loss caused by the decrease in inductance. Please refer to Figure 7 and Figure 8 , Figure 7 This is the torque-current comparison diagram of the motor at a speed of 3000rpm. Figure 8 This is the torque and current comparison diagram of the motor at a speed of 5000rpm. Figure 7 and Figure 8 It can be seen that the reluctance torque of amorphous alloy is obviously at a disadvantage compared with silicon steel, whether before or after the turning speed. According to the above analysis, the deterioration of the magnetic conductivity of amorphous alloy limits the torque output of the motor.

[0103] See also Fig. 9 , Fig. 9 It is the magnetic flux distribution diagram of the motor. Through finite element analysis, it can be concluded that the saturation area is mainly concentrated in three areas (stator yoke part 211, stator teeth 213, 212 and the narrow area of ​​rotor interlayer magnetic steel).

[0104] In order to avoid the above situation, the BH curve of amorphous alloy is optimized, please refer to Fig.10 , Fig.10 It is the BH curve of amorphous alloy, which is divided into linear region and nonlinear region. Among the above three regions, the yoke 211 belongs to the linear region, and its local magnetic flux density is generally less than 1.4T. The stator teeth 213, 212 and the narrow area of ​​the rotor magnetic steel layer belong to the nonlinear region, and their local saturation magnetic flux density is higher than 1.4T.

[0105] Fig.11 is the analytical model of the motor’s magnetic circuit. Fig.11 It can be concluded that in the rotor part, the focus of the d-axis magnetic field and the q-axis magnetic field is at the black dot position in the above figure, that is, the armature and permanent magnet magnetic fields are superimposed, and the highest magnetic density point of the rotor is located at the black dot in the magnetic circuit. Fig. 9The reason why the local saturation point of the rotor in the finite element simulation is located at the narrowest part of the rotor magnetic steel layer bond. To solve the above problem, it is possible to consider optimizing the size of the local saturation area near the black point in the figure.

[0106] In some embodiments, during the actual operation of the motor, the rotor assembly will be locally saturated. In order to reduce the magnetic resistance of the permanent magnetic field in the magnetic circuit passing through the rotor saturation area, the permanent magnet is generally moved closer to the rotor surface. If multiple layers of magnetic steel move toward the rotor surface, the distance between the magnetic steel layers will be too small, resulting in local saturation and a decrease in motor torque. Considering the characteristics of the BH curve of the amorphous alloy, in order to avoid excessive saturation of the interlayer area, the angle α between the first sub-straight segments of any two first magnetic slots 111 needs to be greater than the angle β between the second sub-straight segments of any two second magnetic slots 121, thereby reducing the area of ​​the saturated area on the rotor punching 100.

[0107] For further information, see Figure 1 and Figure 2 In a magnetic slot structure 1, a plurality of first magnetic slots 111 are arranged along a first symmetry line, and a plurality of second magnetic slots 121 are arranged along a second symmetry line. The first symmetry line and the second symmetry line extend radially along the rotor sheet 100. Such an arrangement enables the first magnetic slots 111 and the second magnetic slots 121 to be evenly arranged, thereby ensuring that the tensile strength and structural strength of the rotor sheet 100 remain consistent, thereby improving the service life of the rotor sheet 100.

[0108] It should be noted that the number of the first magnetic slots 111 and the second magnetic slots 121 is not limited and can be set according to actual conditions. In some embodiments, the number of the first magnetic slots 111 is two and the number of the second magnetic slots 121 is four. In other embodiments, the number of the first magnetic slots 111 is two and the number of the second magnetic slots 121 is also two.

[0109] In some embodiments, the plurality of first magnetic slots 111 include a first sub-magnetic slot and a second sub-magnetic slot, and the plurality of second magnetic slots 121 include a third sub-magnetic slot, a fourth sub-magnetic slot, a fifth sub-magnetic slot, and a sixth sub-magnetic slot arranged in sequence, the first sub-magnetic slot corresponds to the fourth sub-magnetic slot, the second sub-magnetic slot corresponds to the fifth sub-magnetic slot, the third sub-magnetic slot is located on a side of the first sub-magnetic slot away from the second sub-magnetic slot, and the sixth sub-magnetic slot is located on a side of the second sub-magnetic slot away from the first sub-magnetic slot. Such an arrangement can avoid stress concentration, increase the speed of the motor, and thereby improve the working efficiency of the motor.

[0110] For further information, please refer to Figure 2, the multiple second magnetic slots 121 form two magnetic slot groups symmetrically distributed along the first symmetry line. In the same magnetic slot group, the second sub-straight line segment of the second magnetic slot 121 closer to the first symmetry line has a larger angle with the first symmetry line. In this way, the multiple second magnetic slots 121 groups can surround the multiple first magnetic slots 111 in an approximately circular arc shape. The circular arc shape can disperse stress in different directions, thereby avoiding stress concentration, increasing the speed of the motor, and further improving the working efficiency of the motor.

[0111] For more details, please refer to Figure 1 and Figure 2 The first magnetic slot assembly and the second magnetic slot assembly 12 are generally distributed in a triangular shape. Through a large number of calculations, when α / β is between 1.03 and 1.89, the area of ​​the local saturation region will be reduced.

[0112] Fig.11 is the analytical model of the motor’s magnetic circuit. Fig.11 It can be concluded that in the rotor part, the focus of the d-axis magnetic field and the q-axis magnetic field is at the black dot position in the above figure, that is, the armature and permanent magnet magnetic fields are superimposed, and the highest magnetic density point of the rotor is located at the black dot in the magnetic circuit. Fig. 9 The reason why the local saturation point of the rotor in the finite element simulation is located at the narrowest part of the rotor magnetic steel layer bond. To solve the above problem, it is possible to consider optimizing the size of the local saturation area near the black point in the figure.

[0113] In some other embodiments, during the actual optimization process, the second magnetic slot assembly 12 is moved toward the inner diameter direction of the rotor punching 100, which can increase the flow width of the q-axis magnetic field here, thereby reducing the q-axis magnetic resistance and its saturation degree. On the other hand, when the second magnetic slot assembly 12 shrinks inward, the length of the magnetic steel magnetic field will be lengthened, that is, the flow length of the d-axis magnetic field will be increased, and the d-axis magnetic resistance will be increased. This will lead to an increase in the motor salient pole ratio (Ld / Lq) or the second half of formula (1), but the magnetic resistance of the permanent magnetic field flow path will also increase, resulting in a decrease in the permanent magnetic flux, and ultimately reducing the output torque. Through the above analysis, local saturation electricity is caused by the interaction between the armature magnetic field and the permanent magnetic field, and both magnetic fields produce a large amount of magnetic pressure drop on the air gap. Within a certain electromagnetic air gap length range (0.5mm~3.0mm), according to formula (2), the magnetic resistance of the air gap is inversely proportional to the cross-sectional area of ​​the air gap, that is, the magnetic resistance is inversely proportional to the radius of the rotor punching 100. In summary, the saturation degree of the rotor is directly related to the cross-axis distance (roughly the rotor radius) and the straight-axis distance (roughly the distance between the rotor magnetic steel slots). Through a large number of calculations, it is concluded that the minimum distance between the first magnetic slot 111 and the second magnetic slot is L3, the outer arc length of the rotor punching 100 is L4, and L3 / L4≥0.05, which will reduce the area of ​​the local saturation region and improve the working efficiency of the motor.

[0114] In some embodiments, a first connection portion 112 is formed between two adjacent first magnetic slots 111, and a second connection portion 122 is formed between adjacent second magnetic slots 121. When the motor is running at high speed, the stress value of the first connection portion 112 and the second connection portion 122 needs to be greater than or equal to 500Mpa, so as to utilize the high tensile strength characteristics of the material due to the disordered arrangement of atoms of the amorphous alloy material, the absence of grains or smaller grains, and improve the tensile strength of the rotor punching 100. The stress value of other parts of the rotor punching 100 needs to be less than or equal to 2300Mpa, so as to avoid the problem of operating reliability caused by the tensile strength of the material in the local area exceeding the tensile limit of the material.

[0115] Amorphous alloys are prepared by extremely rapid cooling. On the one hand, their atomic structure is disordered and has no lattice characteristics. Therefore, they have high tensile strength and are linear elastic bodies without plastic deformation processes. On the other hand, amorphous materials are in a relatively high free energy state and their material properties are unstable. Under certain temperature and pressure conditions, there is a risk of structural relaxation or crystallization, which leads to a significant deterioration in mechanical properties.

[0116] See also Fig.12 , Fig.12 The tensile strength comparison chart of amorphous alloy and silicon steel alloy is shown in Figure 2. Fig.12 It can be concluded that the material elastic modulus (stress / strain) of stamped amorphous alloy is lower than that of silicon steel, and there is no plastic process. The stamped amorphous alloy breaks under 1600Mpa. In addition, the amorphous alloy breaks within a strain range of 2%, indicating that even if the tensile strength of the amorphous alloy is very high, when deformation occurs, its stress increases rapidly, and it is very likely to exceed the limit stress and then break.

[0117] On the other hand, although the tensile strength of silicon steel is less than 500Mpa, the stress on silicon steel does not increase rapidly in a larger strain range due to the plastic deformation of the material. In other words, when the strain is greater than 2%, even if the tensile strength of amorphous alloy is very high, there is still a high risk of fracture.

[0118] In order to allow the rotor to run at a high speed and minimize the performance degradation caused by magnetic tape leakage, the width of the magnetic bridge (ie, the first connecting portion 112 and the second connecting portion 122) should be reduced as much as possible.

[0119] However, in order to overcome the high-speed centrifugal force, it is necessary to optimize the width of the local magnetic bridge (ie, the first connecting portion 112 and the second connecting portion 122 ).

[0120] Unlike silicon steel design, amorphous alloys have high tensile strength, but are easily deformed, and their strain should be reduced as much as possible to avoid breaking due to excessive strain that causes them to approach the stress limit. Through a large number of calculations, it is concluded that when the linear speed of the rotor assembly design is greater than or equal to 160m / s. Furthermore, the minimum distance between two adjacent first magnetic grooves 111 is L1, L1≥0.5mm; the minimum distance between two adjacent second magnetic grooves 121 is L2, L2≥0.5mm. The widths of the first connecting portion 112 and the second connecting portion 122 need to be greater than or equal to 0.5mm, so as to ensure that the strain does not exceed the bearing limit of the amorphous alloy, and the stress value is greater than or equal to 500Mpa, which takes advantage of the high tensile strength of the amorphous alloy and will not cause excessive strain to cause it to break. The strain value of the rotor assembly is less than or equal to 1.15%, and the stress value near the first magnetic groove 111 and the second magnetic groove 121 should be less than or equal to 2000Mpa, thereby reducing the reliability problems caused by high-speed centrifugal force.

[0121] See also Figure 1 and Figure 2 , the contour line of the projection of the first magnetic groove 111 on the side includes a straight line segment and an arc segment; the contour line of the projection of the second magnetic groove 121 on the horizontal plane includes a straight line segment and an arc segment. The shapes of the first magnetic groove 111 and the second magnetic groove 121 are both irregular shapes, and the arc segment can diffuse the stress near the first magnetic groove 111 and the second magnetic groove 121 to different directions, avoid stress concentration, increase the speed of the motor, and thus improve the working efficiency of the motor. The area of ​​the area formed by the arc segment of the first magnetic groove 111 on the front side of the rotation direction and the outer edge of the magnetic steel placed in the corresponding first magnetic groove 111 is smaller than the area of ​​the area formed by the arc segment of the first magnetic groove 111 on the rear side of the rotation direction and the outer edge of the magnetic steel placed in the corresponding first magnetic groove 111; similarly, the area of ​​the area formed by the arc segment of the second magnetic groove 121 on the front side of the rotation direction and the outer edge of the magnetic steel placed in the corresponding second magnetic groove 121 is smaller than the area of ​​the area formed by the arc segment of the second magnetic groove 121 on the rear side of the rotation direction and the outer edge of the magnetic steel placed in the corresponding second magnetic groove 121.

[0122] The performance of amorphous alloys is unstable. In order to maximize the use of the characteristics of amorphous alloys and avoid the risk of deformation, fracture, etc. during the operation of the motor, the number of magnetic slot structures 1 is n1, and the sum of the number of first magnetic slots 111 and second magnetic slots 121 of each magnetic slot structure 1 is n2. n1 / n2 is the magnetic slot factor. Please refer to Fig.13 , Fig.13 It is a schematic diagram of the effect of magnetic slot factor on the limiting speed and output torque. Fig.13 It can be concluded that the structure of the rotor assembly needs to be optimized, that is, multiple magnetic slot structures 1 are provided on the rotor punching 100 to avoid the risk of failure.

[0123] See also Fig.14 In this embodiment, the amorphous alloy itself is obtained by rapidly cooling the molten amorphous alloy 31 by spraying it on the roller 33 through rapid extreme cold. Specifically, the molten amorphous alloy 31 is introduced into the nozzle 32, and the nozzle 32 sprays the molten amorphous alloy 31 on the roller 33, and the roller 33 rotates and squeezes to form an amorphous alloy strip 34. It should be noted that when the cooling rate is as high as 105-106℃ / s to ensure that the metal is difficult to crystallize, irregularly arranged atoms are formed, so as to ensure that it has higher mechanical properties: such as higher tensile strength and compressive strength, magnetic properties: low loss, etc.

[0124] Since the thickness of the amorphous alloy strip 34 is less than 0.05 mm, during processing, it is necessary to consider the problem that the excessively large outer diameter is difficult to punch.

[0125] During the preparation of the amorphous alloy strip 34, the molten amorphous alloy 31 is rapidly cooled by rapid ultra-cold spraying on a roller to obtain a metal strip with a thickness of less than 0.1 mm. The cooling rate is as high as 106°C / s to ensure that the metal is difficult to crystallize and form irregularly arranged atoms, thereby ensuring that it has higher mechanical properties: such as higher tensile strength and compressive strength, and magnetic properties: low loss, etc.

[0126] from Fig.14 As can be seen from the figure, the molten amorphous alloy needs to be released through the nozzle and quickly cooled on the roller. This process results in the amorphous thin strip with a larger width (i.e., perpendicular to the direction of the figure above). The formed amorphous strip is extremely thin, usually between 0.02mm and 0.1mm thick. On the other hand, due to its atomic structure characteristics, the hardness of amorphous alloy is extremely high, with a Vickers hardness of about 900.

[0127] The extremely thin thickness of the sheet and its high hardness make it extremely difficult to stamp a single layer of sheet. The thickness of a single piece of amorphous material is too low. If it is stamped, the mold gap is extremely small, and the mold precision requirements are extremely high. At the same time, the production efficiency of stamping a single layer of amorphous thin film is too low.

[0128] One way is to roll it, see Fig.34 , Fig.34 The preparation process of an embodiment of composite rolling of amorphous alloy thin strip 34 is as follows: Fig.14 The amorphous alloy strip 34 is prepared in a manner, and 5 layers of the amorphous alloy strip 34 are rolled. Anti-adhesion treatment (such as a release agent, a polytetrafluoroethylene film, etc.) is required during the rolling process. After the rolling is completed, the multi-layer amorphous alloy strip 34 is placed in a glue containing a high molecular polymer for vacuum negative pressure impregnation, so that it penetrates into the amorphous alloy strip 34 and is cured to form a composite amorphous plate. The composite amorphous plate is then stamped to obtain a rotor punching 100.

[0129] Another way is bonding, see Fig.35 , Fig.35 Another embodiment of the preparation process of the composite rolling of the amorphous alloy thin strip 34 is as follows: Fig.14 The amorphous alloy strip 34 is prepared in a manner, and the multiple layers of amorphous alloy strips 34 are bonded by rollers (such as gluing, spraying, etc.) to have a certain thickness, and then pressure is applied to bond them together, and then they are cured to form a composite amorphous plate, and then the composite amorphous plate is stamped to obtain the rotor punching 100.

[0130] exist Fig.34 and Fig.35 In the embodiment, the composite amorphous sheet for stamping has a certain thickness, which can effectively improve the stamping efficiency, but at the same time the composite amorphous sheet cannot be too thick, so as to avoid the material being difficult to stamp due to its excessive thickness in the stamping direction. At the same time, the amorphous alloy becomes brittle after being compounded with glue, and is prone to breakage during the stamping process.

[0131] During the stamping process, composite amorphous sheets outside a certain diameter range are prone to breakage, adhesive layer shedding, edge warping, etc. if they are too thin, and difficult to break during stamping, adhesive layer shedding, mold clogging, etc. if they are too thick. Fig.36 , Fig.36 In order to study the influence of the stacking diameter ratio of the rotor punching 100 on the yield rate, a large number of experiments have been conducted to prove that the thickness of each rotor punching 100 is Ls2, the outer diameter of each rotor punching 100 is Ls2, 0.35‰≤Ls2 / Ds2≤2.46‰, wherein Ls2 / Ds2 is the stacking diameter ratio of the rotor punching. Within the above range, it is ensured that the rotor punching 100 will not have damage problems such as adhesion and warping.

[0132] See also Fig.15 and Fig.16 , Fig.15 Schematic diagram of the atomic arrangement of silicon steel. Fig.16 This is a schematic diagram of the arrangement of atoms in an amorphous alloy. Fig.15 and Fig.16 It can be concluded that the atoms in amorphous alloys are arranged in a disordered manner through rapid extreme cooling. Due to the disordered atomic characteristics of amorphous alloys, there is no lattice or grain boundary inside the amorphous alloy. Due to the absence of lattice characteristics, the tensile strength of the material is higher than that of silicon steel.

[0133] See also Fig.17 , Fig.17 This is a schematic diagram to represent the process of metal from molten state to crystal state. Fig.17It can be seen that the free energy of the amorphous state is higher than that of the crystalline state, indicating that its material properties are unstable. Under certain conditions of temperature, pressure, etc., there is a possibility of transformation from the amorphous state to the crystalline state, and then there is a risk of a decrease in mechanical properties such as tensile strength.

[0134] Considering that the motor core may be subjected to stamping, cutting, heating and other conditions during the preparation and operation process, the mechanical properties of amorphous materials may deteriorate. Fig.18 , Fig.18 This is a comparison chart of the tensile strength of materials under different processing conditions. Fig.18 It can be concluded that, since the amorphous alloy strip 34 is extremely thin, in order to improve its preparation efficiency, multi-layer composite and processing are generally used to compensate for it. However, the thickness of the glue layer between the laminations of the amorphous alloy strip 34 is extremely thin, and there is a risk of peeling during processing, transportation and operation. After the first layer of amorphous alloy strip 34 is peeled off, it will cause the subsequent amorphous alloy strips 34 to continue to be lifted and peeled off, thereby forming a core lamination phenomenon. Because during the stamping process, it is inevitable that a stress zone will be formed on the edge of the amorphous alloy strip 34. On the other hand, at the microscopic level, the stamping and cutting action will form a defective opening at the edge of the amorphous alloy strip 34. When the peeled amorphous alloy strip 34 is subjected to external force, if stress concentration occurs, the amorphous alloy strip 34 will be torn at the defective opening, thereby causing local damage to the rotor assembly.

[0135] See also Fig.19 When the amorphous alloy strip 34 is partially damaged, the damage will gradually worsen and extend to the inside. If an amorphous alloy is used as a rotor, damage will occur, and in severe cases, safety problems such as bore scraping will occur.

[0136] Taking the above problems into consideration, in order to improve the reliability of the motor, especially on the rotor assembly, the stamping affected area should be minimized, that is, the number of the first connecting parts 112 and the second connecting parts 122 should be reduced, and the area of ​​the stress concentration zone should be increased as much as possible, that is, the width of the first connecting part 112 and the second connecting part 122 should be increased to reduce the stress concentration phenomenon.

[0137] See also Fig. 20 , Fig.21 and Fig. 22 , Fig. 20 Schematic diagram of the effect of pole number on stress; Fig.21 This is a schematic diagram of the effect of pole number on peak torque and operating efficiency. Fig. 22 Schematic diagram of the effect of the width of the first connection portion 112 and the second connection portion 122 on power and efficiency.

[0138] At the same time, as the motor speed increases, in order to overcome the centrifugal force, the width of the first connection part 112 and the width of the second connection part 122 should be increased as much as possible, and at the same time, the number of the first connection part 112 and the number of the second connection part 122 should be increased to reduce the stress problem as much as possible. However, on the other hand, the increase in the width of the first connection part 112 and the second connection part 122, or the increase in the number of the first connection part 112 and the second connection part 122, will increase the magnetic leakage of the rotor permanent magnet, reduce the effective magnetic flux of the motor, and cause the motor output capacity to decrease.

[0139] The number of magnetic slot structures 1 is the number of motor poles. Under the same magnetic slot structure 1, the sum of the number of the first magnetic slots 111 and the second magnetic slots 121 is the magnetic pair number of the motor. When the motor is at a certain speed, the more poles it has, the more magnetic slot structures 1 of the motor will be, and the stronger its ability to overcome centrifugal force will be. However, the increase in the number of pole pairs will lead to an increase in the motor frequency, and the iron loss will also increase, thereby reducing the motor efficiency. At the same time, considering the increase in the number of the first connecting part 112 and the second connecting part 122, the leakage flux may increase to a certain extent, and more armature magnetic fields are required to provide the same torque.

[0140] The saturation magnetic flux density of amorphous alloys is lower than that of silicon steel, so the leakage flux at the positions of the first connection part 112 and the second connection part 122 is lower than that of silicon steel. Because there is no lattice or grain boundary in amorphous alloys, their tensile strength is significantly improved compared to silicon steel. In summary, considering the magnetic properties and mechanical properties of amorphous alloys, combined with the influence of stamping or other processing methods on the mechanical properties of amorphous alloys, through a large number of analyses, it is concluded that 0.66≤n1 / n2≤7. When 0.66≤n1 / n2≤7, it can be ensured that the amorphous alloy has enough first magnetic grooves 111 and second magnetic grooves 121 during high-speed rotation to overcome the influence of centrifugal force, while minimizing the problem of increased leakage flux caused by too many first connection parts 112 and second connection parts 122.

[0141] The present application also provides a rotor assembly, which includes the above-mentioned rotor punching 100. The rotor assembly is formed by stacking a plurality of the above-mentioned rotor punchings 100. The rotor assembly has all the beneficial effects of the above-mentioned rotor punchings 100, which will not be described in detail in the present application.

[0142] The present application provides a stator assembly 200, see Fig.23 The stator assembly 200 includes a stator core 21 and a stator cover plate 22 . The stator cover plate 22 is fixed to two opposite ends of the stator core 21 along its axial direction. The stator core 21 includes a plurality of stator punching sheets 210 stacked together.

[0143] Please participate Fig.24The stator sheet 210 includes a yoke 211 and a tooth 212. The yoke 211 is arranged near the edge of the stator sheet 210, and the tooth 212 is located on a side near the center line of the rotor sheet 100. In some embodiments, refer to Fig.25 and Fig.26 The tooth portion 212 includes a plurality of stator teeth 213 , and the plurality of stator teeth 213 are arranged at intervals on the yoke 211 . Each stator tooth 213 includes a connected tooth end 214 and a tooth shoulder 215 . The tooth end 214 is connected to the yoke 211 , and the width of the tooth shoulder 215 is greater than the width of the tooth end 214 .

[0144] In some embodiments, at least one tooth shoulder 215 is provided with grooves 216 along two radially opposite sides thereof. The grooves 216 can increase the magnetic resistance of the tooth shoulder 215 in the circumferential direction, and can effectively reduce the magnetic field flowing between the tooth shoulders 215 and the tooth shoulders 215, and reduce magnetic leakage; at the same time, the grooves 216 reduce magnetic leakage, and can change the magnetic field saturation area, which has a certain effect on changing the magnetic field torque pulsation and radial electromagnetic force.

[0145] More specifically, in this embodiment, the groove 216 is in an arc shape.

[0146] It should be noted that the number of the tooth shoulders 215 with the grooves 216 is not limited and can be selected according to actual conditions.

[0147] In some embodiments, each tooth shoulder 215 is provided with a groove 216 .

[0148] In some other embodiments, the plurality of tooth shoulders 215 form a plurality of tooth shoulder groups, each tooth shoulder group includes two tooth shoulders 215 with grooves 216 , and n tooth shoulders 215 without grooves 216 are disposed between the two tooth shoulders 215 .

[0149] In one embodiment, each tooth shoulder group includes 9 tooth shoulders 215. Along the clockwise direction, the 9 tooth shoulders 215 are respectively tooth shoulder e1, tooth shoulder e2, tooth shoulder e3, tooth shoulder e4, tooth shoulder e5, tooth shoulder e6, tooth shoulder e7, tooth shoulder e8, and tooth shoulder e9. Among them, tooth shoulder e1, tooth shoulder e3, tooth shoulder e5, tooth shoulder e7, and tooth shoulder e9 are all provided with grooves 216, while tooth shoulder e2, tooth shoulder e4, tooth shoulder e6, and tooth shoulder e8 are not provided with grooves 216.

[0150] In some other embodiments, the tooth shoulder group includes a first tooth shoulder group and a second tooth shoulder group, the first tooth shoulder group is provided with 9 tooth shoulders, and the second tooth shoulder group is provided with 9 tooth shoulders. Along the clockwise direction, the first tooth shoulder group is respectively tooth shoulder k1, tooth shoulder k2, tooth shoulder k3, tooth shoulder k4, tooth shoulder k5, tooth shoulder k6, tooth shoulder k7, tooth shoulder k8, and tooth shoulder k9; in the first tooth shoulder group, tooth shoulder k1, tooth shoulder k3, tooth shoulder k6, and tooth shoulder k9 are all provided with grooves 216, and tooth shoulders k2, tooth shoulders k4, tooth shoulders k5, tooth shoulders k7, and tooth shoulders k8 are not provided with grooves 216. The second tooth shoulder group includes tooth shoulder g1, tooth shoulder g2, tooth shoulder g3, tooth shoulder g4, tooth shoulder g5, tooth shoulder g6, tooth shoulder g7, tooth shoulder g8 and tooth shoulder g9. In the second tooth shoulder group, tooth shoulder g1, tooth shoulder g4, tooth shoulder g8 and tooth shoulder g9 are all provided with grooves 216, while tooth shoulder g2, tooth shoulder g3, tooth shoulder g5, tooth shoulder g6 and tooth shoulder g7 are not provided with grooves 216.

[0151] In some embodiments, the volume of the groove 216 should not be too large, otherwise it will affect the tooth end 214. The volume of the groove 216 should not be too small, otherwise it will not be possible to reduce magnetic leakage. Specifically, in the same tooth shoulder 215, the maximum dimension of the groove 216 in the radial direction of the stator core 21 is D1, and the dimension of the tooth shoulder 215 in the radial direction of the stator core 21 is D2, 0.05≤D1 / D2≤0.2. Further, it can be understood that in a tooth shoulder 215, the volume of the groove 216 is V1, and the volume of the area on the tooth shoulder 215 where the groove 216 is not provided is V2, 0.05≤V1 / (V1+V2)≤0.2. Please refer to Fig.33 ,by Fig.33 The first dividing line 41, the second dividing line 42 and the third dividing line 43 in the embodiment are taken as an example (the first dividing line 41, the second dividing line 42 and the third dividing line 43 do not exist in the actual product. Fig.33 The first dividing line 41, the second dividing line 42 and the third dividing line 43 are only for explaining the specific structure of the tooth end 214. Fig.33 The area indicated by p3 is the area on the tooth shoulder 215 where the groove 216 is set, that is, the volume of the area indicated by p3 is V2, and p1 and p2 refer to the areas on both sides of the tooth shoulder 215 where the grooves are set, that is, the volume of the area indicated by p1 plus the area indicated by p2 is V1.

[0152] See also Fig.23The stator core 21 is formed by a plurality of stacked stator punching sheets 210. The stator cover plate 22 is arranged at two ends of the stator core that are arranged opposite to each other along its axial direction, and is fixed to the stator core 21 by gluing to ensure that the stator punching sheets 210 do not produce edge warping. At the same time, the damage of the insulating paint film of the hairpin in the hairpin insertion caused by the high hardness of the amorphous alloy thin strip 34 during the assembly process of the stator assembly 200 can be improved. The stator cover plate 22 can be processed by a variety of metal materials such as silicon steel sheets and stainless steel.

[0153] The structure of the stator cover plate 22 is consistent with that of the stator punching sheet 210 , and will not be described in detail here.

[0154] In some embodiments, please refer to Fig.25 The stator sheet 210 is also provided with a plurality of oil holes, which are arranged at intervals and are located on the side of the tooth portion 212 away from the center line of the stator sheet 210. The oil holes are used for cooling oil to pass through, thereby cooling the motor.

[0155] Please continue reading Fig.25 and Fig.26 , the radial length of the yoke 211 is he, the radial length of the tooth 212 is hc, Fig. 27 This is a schematic diagram of the effect of hc / he on the output torque. Fig. 27 It can be concluded that 0.95≤hc / he≤1.52, where hc / he is the tooth-yoke ratio. The tooth-yoke ratio is between 0.95 and 1.52 to ensure that the stator punching 210 will not be over-saturated. For finite element calculation, when the motor works at the rated operating point, the maximum magnetic flux density of the yoke 211 is less than or equal to 1.5T, and the magnetic flux density of the tooth 212 is less than or equal to 1.7T; at the maximum torque operating point, the maximum magnetic flux density of the yoke 211 is less than or equal to 1.7T, and the maximum magnetic flux density of the tooth 212 is less than or equal to 1.8T, so as to avoid local over-saturation and maximize the efficiency advantage of the amorphous motor.

[0156] Specifically, see Fig.14 The stator punching sheets 210 are all formed by the amorphous alloy thin strips 34. The formation process of the amorphous alloy thin strips 34 can refer to the above embodiment and will not be described in detail here.

[0157] Please continue reading Fig.14, the molten amorphous alloy 31 needs to be released through the nozzle 32 and quickly cooled on the roller 33. In this process, the wider the amorphous alloy strip 34 is, the more difficult it is to form. The difficulty in forming is mainly to control the uniformity of the molten amorphous alloy 31. The wider the amorphous alloy strip 34 is, the worse the uniformity of the molten amorphous alloy 31 is, that is, the manufacturing yield is low. At present, the width of the amorphous alloy strip 34 with a higher yield of the stator punch 210 is generally below 200mm. Considering that the maximum diameter of the stator assembly 200 of the motor may be greater than 200mm, in order to improve the manufacturing yield of the stator assembly 200, the iron content in the amorphous alloy strip 34 is appropriately reduced from the preparation process to improve the uniformity of the amorphous alloy strip 34. On the other hand, reducing the iron content in the amorphous alloy strip 34 can increase the resistivity of the amorphous alloy strip 34, thereby reducing the eddy current loss of the amorphous alloy strip 34.

[0158] Specifically, the eddy current loss expression is:

[0159] P∝(U 2 / R)=(U 2 s) / (pl) (3)

[0160] In formula (3), U is the induced potential generated by the alternating magnetic field, s is the conductor cross-sectional area (i.e., the thickness of the amorphous alloy strip 34), l is the length of the induced current flow path, and ρ is the eddy current path resistivity (i.e., the resistivity of the amorphous alloy strip 34).

[0161] It can be concluded from formula (3) that in order to reduce the eddy current loss of the amorphous alloy strip 34, the resistivity ρ of the amorphous alloy strip 34 needs to be increased. Iron is a good conductor element. When the iron content in the amorphous alloy strip 34 is too much, the resistivity ρ of the amorphous alloy strip 34 will decrease, and the eddy current loss of the amorphous alloy strip 34 will increase, thereby bringing the risk of reduced motor efficiency. On the other hand, iron is a magnetic conductive element. Reducing the iron content of the amorphous alloy strip 34 will cause the saturation magnetic flux density Bs of the amorphous alloy strip 34 to decrease. Please refer to Figure 6 , compared with the Bs of silicon steel, the Bs of amorphous alloy is nearly 20% lower. The Bs of the amorphous alloy strip 34 will result in insufficient output torque when the motor is overloaded.

[0162] See also Fig.28 , Fig.28 Schematic diagram of the comparison of magnetic permeability curves of amorphous alloy and silicon steel. Fig.28 It can be concluded that when the iron element in the amorphous alloy is reduced, the magnetic permeability of the amorphous alloy decreases rapidly during the load increase, and is even lower than that of silicon steel, resulting in magnetic circuit saturation during motor operation. A larger armature current is required to ensure the motor torque. The increase in armature current will increase the copper loss of the motor and reduce the operating efficiency of the motor.

[0163] Considering the inherent characteristics of amorphous alloys, in order to improve the output performance of the motor and avoid the problem of increased iron loss when the motor cannot output sufficient torque due to excessive saturation of the magnetic circuit, it is necessary to optimize the design of the motor tooth yoke ratio in combination with amorphous alloys.

[0164] Through finite element calculation, when the amorphous motor works at the rated working point, the maximum magnetic flux density of the yoke 211 is less than or equal to 1.5T, and the magnetic flux density of the tooth 212 is less than or equal to 1.7T; at the maximum torque working point, the maximum magnetic flux density of the yoke 211 is less than or equal to 1.7T, and the maximum magnetic flux density of the tooth 212 is less than or equal to 1.8T, so as to avoid local oversaturation and maximize the efficiency advantage of the amorphous motor. Amorphous alloys have advantages such as low loss and good mechanical strength, but they also have problems such as low saturation magnetic flux density.

[0165] Please continue reading Figure 6 , Figure 7 , Figure 8 , Fig. 9 , Fig.10 The causes of the low saturation magnetic flux density of the stator punching 210 and the low magnetic saturation density of the rotor punching 100 are the same as those of the rotor punching 100. Please refer to the relevant embodiments of the rotor punching 100 and will not be elaborated here.

[0166] See also Fig. 9 and Fig.29 , Fig.29 FIG. 2 is a schematic diagram of the magnetic circuit of the stator assembly 200. Fig. 9 and Fig.29 It can be concluded that the saturation area of ​​the motor is mainly concentrated in three areas: the yoke 211, the tooth 212, and the narrow area of ​​the rotor interlayer magnetic steel. Fig.10 and Fig.29 It can be concluded that the yoke 211 belongs to the linear region, and its local magnetic flux density is generally less than 1.4T, and the tooth 212 and the narrow area of ​​the rotor magnetic steel layer belong to the nonlinear region, and its local saturation magnetic flux density is higher than 1.4T.

[0167] In order to improve the saturation degree of the stator punching sheet 210, according to formula (3), it is possible to choose to reduce the flow length l of the magnetic field or increase the flow width h (i.e., flow area s). However, in fact, due to the limitations of the diameter of the stator assembly 200 of the motor and the number of pole pairs of the rotor assembly, the pole pitch is basically fixed, and the flow length l of the magnetic field is difficult to further reduce. Therefore, it is preferred to increase the flow width h (i.e., flow area s) to improve saturation. The flow area of ​​the yoke 211 is the area of ​​the yoke 211. For the tooth 212, due to the area limitation of the stator slot, increasing the width of the tooth 212 will occupy the winding cross-sectional area in the stator slot, resulting in an increase in the motor resistance, which is disadvantageous; and by reducing the flow length, that is, reducing the length of the tooth 212, the magnetic resistance of the magnetic circuit can be reduced almost linearly, improving saturation. Therefore, it is preferred to reduce the flow length to improve saturation.

[0168] Finite element analysis shows that the yoke 211 is in the linear magnetic circuit area, and the magnetic flux density decreases linearly by increasing the magnetic field flow width, and the magnetic resistance decreases rapidly, but is limited by the pole pitch of the motor, and its magnetic field flow length is fixed. The tooth 212 is in the nonlinear magnetic circuit area, and the magnetic resistance can be rapidly reduced by reducing the magnetic field flow length, but is limited by the stator winding space (the width of the tooth 212 cannot be greatly increased), and the magnetic resistance does not decrease significantly when the magnetic field flow width increases.

[0169] The motor output characteristics and efficiency can be improved by reasonably increasing the width of the yoke 211 and reducing the length of the tooth 212. However, excessively increasing the height of the yoke 211 and reducing the length of the tooth 212 will result in too small a stator winding space, thereby increasing the motor copper loss and reducing the efficiency and output characteristics.

[0170] See also Fig.30 , Fig.31 and Fig.32 , Fig.30 It is a schematic diagram of the iron loss distribution outside the protection range of the gear-yoke ratio; Fig.31 It is a schematic diagram of the iron loss distribution within the protection range of the gear-yoke ratio; Fig.32 This is a schematic diagram comparing hc / he and motor efficiency. Fig.30 , Fig.31 and Fig.32 It can be concluded that hc / he should be between 0.95 and 1.52, which has both higher output torque and higher efficiency.

[0171] The stator punching sheet 210 is formed by solidifying 3 to 6 layers of amorphous alloy thin strips 34 together. When the number of solidified amorphous alloy thin strips 34 is too many, the hardness of the stator punching sheet 210 is high, resulting in a short mold life. When the number of solidified amorphous alloy thin strips 34 is too few, the thickness of the stator punching sheet 210 is thin, resulting in a long processing time. The number of stator punching sheets 210 contained in a single stator core 21 is 100 to 300, which are bonded together by glue. The stator assembly 200 is stacked in sequence by 4 to 16 layers of stator cores 21. When the number of layers of the stator core 21 is too many, the processing time becomes longer. When the number of layers of the stator core 21 is too few, the stator assembly 200 is prone to wave patterns.

[0172] Furthermore, hc / he is between 1.1 and 1.4 to ensure that the amorphous material will not be over-saturated. Through finite element calculation, when the amorphous motor operates at the rated operating point, the maximum magnetic flux density of the yoke 211 is less than or equal to 1.5T, and the magnetic flux density of the tooth 212 is less than or equal to 1.7T; when the amorphous motor operates at the maximum torque operating point, the maximum magnetic flux density of the yoke 211 is less than or equal to 1.7T, and the maximum magnetic flux density of the tooth 212 is less than or equal to 1.8T, so as to avoid local over-saturation and maximize the efficiency advantage of the amorphous motor.

[0173] Specifically, the rotor punching sheet 100 and the stator punching sheet 210 are both formed by amorphous alloy thin strips 34. The amorphous alloy thin strips 34 and the like are applied to the stator and rotor assembly and the stator assembly 200 of the motor to effectively reduce the eddy current flow area and increase the resistance, thereby reducing high-frequency eddy current losses. However, the amorphous alloy strip 34 is currently only 0.027 mm thick, so it is difficult to prepare it into a rotor assembly and a stator assembly 200. At the same time, in order to reduce high-frequency losses, the traditional core stamping and riveting combination is removed, and a bonded core is adopted. Considering the thickness of the amorphous alloy strip 34, multiple layers (2 to 10 layers) of amorphous alloy strips 34 are compounded together for stamping. Considering the problem that the stator outer diameter is too large and difficult to stamp, at least two layers of amorphous alloy strips 34 are compounded to form a stator punching sheet 210 with a thickness of Ls. The stacking coefficient of the stator punching sheet 210 is the ratio of Ls to the outer diameter Ds of the stator punching sheet 210, and Ls / Ds should be set between 0.19‰-1.68‰.

[0174] At the same time, the current maximum width of the amorphous alloy strip 34 is 240 mm (and the molding difficulty is relatively high), and there is a situation where it cannot be fully adapted to the motor. In order to ensure that large outer diameter motors are stamped using the above-mentioned strip and save raw materials, a modular design (core modularization, assembled into a circular core, petal structure, and yoke separation structure after stamping) can be used.

[0175] The present application also provides a powertrain, which includes the above-mentioned motor. The powertrain has all the beneficial effects of the above-mentioned motor, which will not be described in detail in the present application.

[0176] The present application also provides a vehicle, which includes the above-mentioned power assembly. The vehicle has all the beneficial effects of the above-mentioned power assembly, which will not be described in detail in the present application.

[0177] The vehicle may be a fuel vehicle, a plug-in hybrid vehicle or a new energy vehicle, etc., and this application does not make any specific limitation on this.

[0178] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0179] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0180] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0181] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A rotor punching, characterized in that: The rotor sheet is formed with one or more magnetic slot structures, each of which includes a first magnetic slot assembly and a second magnetic slot assembly spaced apart in a radial direction of the rotor sheet, wherein the second magnetic slot assembly is located radially inward of the first magnetic slot assembly, wherein: The first magnetic slot assembly includes a plurality of first magnetic slots, the plurality of first magnetic slots have center lines extending along the arrangement direction of the first magnetic slots, and the angle between the center lines of any two first magnetic slots is α; The second magnetic slot assembly includes a plurality of second magnetic slots, the plurality of second magnetic slots have a center line extending along an arrangement direction of the second magnetic slots, and an angle between the center lines of any two second magnetic slots is β; 0.75≤α / β≤1.9。 2. The rotor punching according to claim 1, characterized in that: The contour line of the projection of each first magnetic slot on the cross section of the rotor punching includes at least one first straight line segment, at least one first straight line segment includes a first sub-straight line segment with the longest length, and the angle between the first sub-straight line segments of any two first magnetic slots is α; The contour line of the projection of each second magnetic slot on the cross section of the rotor punching includes at least one second straight line segment, at least one second straight line segment includes a second sub-straight line segment with the longest length, and the angle between the second sub-straight line segments of any two second magnetic slots is β; Among them, 0.75≤α / β≤1.

9.

3. The rotor punching according to claim 1, characterized in that: 1.03≤α / β≤1.89。 4. The rotor punching according to claim 1, characterized in that: The first magnetic slot assembly has a first symmetry line extending in the radial direction of the rotor sheet, and the first magnetic slots are arranged in an axisymmetric manner along the first symmetry line; The second magnetic slot assembly has a second symmetry line extending in the radial direction of the rotor sheet, and a plurality of the second magnetic slots are arranged in an axisymmetric manner along the second symmetry line.

5. The rotor punching according to claim 2, characterized in that: The second magnetic slot assembly has a second symmetry line extending in the radial direction of the rotor punching sheet, and a plurality of the second magnetic slots form two magnetic slot groups symmetrically distributed along the second symmetry line. In the same magnetic slot group, the second sub-straight line segment of the second magnetic slot closer to the second symmetry line has a larger angle with the second symmetry line.

6. The rotor punching according to claim 1, characterized in that: The minimum distance between two adjacent first magnetic grooves is L1, L1 ≥ 0.5 mm; and / or, The minimum distance between two adjacent second magnetic grooves is L2, and L2≥0.5 mm.

7. The rotor punching according to claim 1, characterized in that: In the rotor punching sheet, the number of the magnetic slot structures is n1, the sum of the number of the first magnetic slots and the second magnetic slots of each magnetic slot structure is n2, and 0.66≤n1 / n2≤7.

8. The rotor punching according to claim 1, characterized in that: The minimum distance between the first magnetic groove and the second magnetic groove is L3, the outer arc length of the rotor punching is L4, and L3 / L4≥0.

05.

9. The rotor punching according to claim 1, characterized in that: The shortest distance between two adjacent magnetic slot structures is H1, and H1 ≥ 1 mm.

10. A rotor assembly, characterized in that: The rotor assembly is formed by stacking rotor laminations as described in any one of claims 1-9.

11. A motor, characterized in that: include: a housing, wherein a stator assembly is disposed on the housing; and The motor shaft is at least partially rotatably mounted in the housing, and a rotor assembly is provided on the motor shaft. The rotor assembly is the rotor assembly as claimed in claim 10.

12. The motor according to claim 11, characterized in that The stator assembly includes a stator core, and the stator core includes a plurality of stator punching sheets stacked together.

13. The motor according to claim 12, characterized in that The stator punching sheet includes a connected yoke portion and a tooth portion, the yoke portion is located outside the stator punching sheet, and the tooth portion is located close to the inside of the stator punching sheet. The radial length of the yoke portion is he, and the radial length of the tooth portion is hc, 0.95≤hc / he≤1.

52.

14. The motor according to claim 13, characterized in that 1.1≤hc / he≤1.

4.

15. The motor according to claim 13, characterized in that The tooth portion includes a plurality of stator teeth, which are spaced apart on the yoke portion. Each of the stator teeth includes a connected tooth end and a tooth shoulder. The tooth end is connected to the yoke portion, and the width of the tooth shoulder is greater than the width of the tooth end.

16. The motor according to claim 15, characterized in that At least one of the tooth shoulders is provided with grooves along two radially opposite sides thereof.

17. The electric machine according to claim 16, characterized in that Each tooth shoulder is provided with a groove.

18. The motor according to claim 16, characterized in that The plurality of tooth shoulders provided with the grooves form a plurality of tooth shoulder groups, each of the tooth shoulder groups includes two tooth shoulders, and at least one tooth shoulder without the groove is provided between the two tooth shoulders.

19. The electric machine according to claim 18, characterized in that The number of the tooth shoulders without the grooves between the two tooth shoulders of each tooth shoulder group is the same; or, The number of the tooth shoulders without the grooves between the two tooth shoulders of at least one tooth shoulder group is different from the number of the tooth shoulders without the grooves between the two tooth shoulders of another tooth shoulder group.

20. The electric machine according to claim 16, characterized in that In the same tooth shoulder, the maximum dimension of the groove in the radial direction of the stator core is D1, and the dimension of the tooth shoulder in the radial direction of the stator core is D2, and 0.05≤D1 / D2≤0.

2.

21. The electric machine according to claim 12, characterized in that The thickness of each stator punching sheet is Ls1, the outer diameter of each stator punching sheet is Ds1, and 0.19‰≤Ls1 / Ds1≤1.68‰.

22. The motor according to claim 12, characterized in that The thickness of each of the rotor punching sheets is Ls2, the outer diameter of each of the rotor punching sheets is Ls2, and 0.35‰≤Ls2 / Ds2≤2.46‰.

23. The electric machine according to claim 12, characterized in that The stator assembly further comprises two stator cover plates, and the two stator cover plates are fixed to two ends of the stator core which are arranged opposite to each other along the axial direction.

24. A powertrain, characterized in that: Comprising a motor as described in any one of claims 11-23.

25. A vehicle, characterized in that: Comprising the powertrain as claimed in claim 24.

Images