Permanent magnet assisted synchronous reluctance machine rotor structure and permanent magnet assisted synchronous reluctance machine

Abstract

The application provides a kind of permanent magnet auxiliary synchronous reluctance motor rotor structure and permanent magnet auxiliary synchronous reluctance motor, including rotor core, center line from the center of rotor core extends radially outward and intersects with the radial outer periphery of rotor core at point M, at least two air slots are provided on rotor core;Air slot is B along the width of circumferential, the width of first magnetic isolation bridge is w1, there is a constraint relationship: B=(3.5-3.7)×10^8 / (w1*nmax^2), the ratio of the distance of MN and the distance of MP MN / MP=0.5-0.52.According to the application, the larger centrifugal force generated at high speed rotation is reduced at the same time, and the electromagnetic performance is effectively guaranteed, the rotor core of permanent magnet auxiliary synchronous reluctance motor is subjected to larger centrifugal force at high speed rotation, the stress of magnetic isolation bridge is larger, and the mechanical strength of rotor is lower.

Description

TECHNICAL FIELD

[0001] The present application relates to the motor technical field, and in particular to a permanent magnet auxiliary synchronous reluctance motor rotor structure and a permanent magnet auxiliary synchronous reluctance motor. BACKGROUND

[0002] With people's increasing attention to environmental protection and energy efficient use, the new four automotives have become the industry consensus, and the electric vehicle wave is more and more turbulent. For new energy vehicles, battery technology, motor technology and motor controller technology are known as the key three electric technologies of new energy vehicles. Under the premise that the current battery technology has not made a breakthrough, improving the efficiency, power density, safety and reliability of the motor drive system has become the main research direction of the new energy vehicle motor drive system.

[0003] The permanent magnet auxiliary synchronous reluctance motor is widely used in pure electric or hybrid new energy vehicles because of its high torque density, high efficiency, good stability and high reliability.

[0004] With the rising price of rare earth raw materials, the cost of rare earth motor is greater, and the maximum torque is output with the least cost to meet the vehicle performance, and the cost performance of the motor is improved. Therefore, the research and development of the permanent magnet auxiliary synchronous reluctance motor with relatively low cost is of great significance. The rotor of the permanent magnet auxiliary synchronous reluctance motor usually adopts a multi-layer magnetic barrier structure to obtain a higher reluctance torque, and a magnetic bridge is added to maintain the mechanical strength of the motor during operation. However, since the width of the magnetic bridge is usually small, the mechanical strength of the rotor is one of the difficulties in design and manufacture. When the motor is running at high speed, the centrifugal force is particularly prominent, far greater than the influence of other forces, and the centrifugal force is proportional to the square of the speed, and with the increase of the speed, the centrifugal force increases greatly, and the problem of excessive stress of the magnetic bridge and rotor damage is easily caused.

[0005] Because the rotor core of the permanent magnet auxiliary synchronous reluctance motor in the prior art is subjected to a large centrifugal force when rotating at high speed, the stress on the magnetic bridge is large, resulting in low mechanical strength of the rotor, and the like. Therefore, the present application researches and designs a permanent magnet auxiliary synchronous reluctance motor rotor structure and a permanent magnet auxiliary synchronous reluctance motor. SUMMARY

[0006] Therefore, the present application aims to overcome the defects of the rotor core of the permanent magnet auxiliary synchronous reluctance motor in the prior art, which is subjected to a large centrifugal force when rotating at high speed, resulting in a large stress on the magnetic bridge and low mechanical strength of the rotor, thereby providing a permanent magnet auxiliary synchronous reluctance motor rotor structure and a permanent magnet auxiliary synchronous reluctance motor.

[0007] In order to solve the above problems, the present application provides a permanent magnet auxiliary synchronous reluctance motor rotor structure, which comprises:

[0008] A rotor core has a plurality of magnetic poles, in any magnetic pole and in the axial projection plane, the rotor core has a center line extending radially outward from the center of the rotor core and intersecting the radial outer periphery of the rotor core at point M, at least two air slots are provided on the rotor core, including a first air slot and a second air slot, the first air slot and the second air slot are symmetrically arranged relative to the center line, at least two magnetic steel grooves are provided on the rotor core, including a first magnetic steel groove closest to the first air slot and a second magnetic steel groove closest to the second air slot, the first magnetic steel groove and the second magnetic steel groove are also symmetrically arranged relative to the center line.

[0009] The width of the air slot in the circumferential direction is B, the first magnetic steel groove radially inner cavity and the second magnetic steel groove radially inner cavity between the first magnetic bridge, the width of the first magnetic bridge is w1, wherein there is a constraint relationship: B=(3.5-3.7)×10^8 / (w1*nmax^2), wherein nmax is the highest speed of motor design, the intersection of the connecting line between the end of the first air slot closest to the center line and the end of the second air slot closest to the center line and the center line is N, the radial outer side end of the first magnetic bridge Q1 intersects the center line at P, wherein the ratio of the distance MN to the distance MP is MN / MP=0.5-0.52.

[0010] In some embodiments,

[0011] B=4.5 / w1, w1=1.5-2mm.

[0012] In some embodiments,

[0013] w1=1.8mm, nmax=9000rpm, MN / MP=0.515.

[0014] In some embodiments,

[0015] The first air slot and the first magnetic steel groove are located on the same side of the center line in the circumferential direction, and the shortest distance between the first air slot and the first magnetic steel groove in the circumferential direction is x, the value of x is 3-3.3mm, the edge of the first air slot facing the center line is the first air slot first edge, the edge of the second air slot facing the center line is the second air slot first edge, and the included angle between the first air slot first edge and the second air slot first edge is Ak, the value of Ak is Ak=360deg / poles±2deg, poles is the number of poles, and deg is the degree of angle.

[0016] In some embodiments,

[0017] x = 3.14 mm; Ak = 360 deg / poles, poles = 8.

[0018] In some embodiments,

[0019] The magnetic steel slot further comprises a third magnetic steel slot located on a circumferential side of the first magnetic steel slot away from the center line, and a fourth magnetic steel slot located on a circumferential side of the second magnetic steel slot away from the center line, the magnetic steel slot further comprises a fifth magnetic steel slot located radially inside the first magnetic steel slot and the second magnetic steel slot, the third magnetic steel slot and the fourth magnetic steel slot are also symmetrically arranged relative to the center line, and the fifth magnetic steel slot is also symmetric relative to the center line.

[0020] In some embodiments,

[0021] The cavity radially inside the third magnetic steel slot and the fifth magnetic steel slot closest to the third magnetic steel slot are separated by a second magnetic bridge, and the cavity radially inside the fourth magnetic steel slot and the fifth magnetic steel slot closest to the fourth magnetic steel slot are separated by a third magnetic bridge; the width of the second magnetic bridge and the third magnetic bridge is w2.

[0022] And there is a constraint relationship: w2-w1 = 0.2-0.4mm.

[0023] In some embodiments,

[0024] In the projection plane of the axial end surface of the rotor core: the first magnetic bridge is a rectangular structure, the edge of the first magnetic bridge located on the radially outer side intersects the center line at point Q1a, and the edge of the first magnetic bridge located on the radially inner side intersects the center line at point Q1b;

[0025] The second magnetic bridge is a rectangular structure, the length midpoint of the edge of the second magnetic bridge closest to the center line is Q2a, and the length midpoint of the edge of the second magnetic bridge farthest from the center line is Q2b;

[0026] The third magnetic bridge is a rectangular structure, the length midpoint of the edge of the third magnetic bridge closest to the center line is Q3a, and the length midpoint of the edge of the third magnetic bridge farthest from the center line is Q3b; the included angle between the line connecting Q1a and Q2b and the line connecting Q1a and Q3b is A1, and the included angle between the line connecting Q1b and Q2a and the line connecting Q1b and Q3a is A2; the included angle between the width center line of the second magnetic bridge and the width center line of the third magnetic bridge is Aq, and A1, A2 and Aq have a constraint relationship:

[0027] A1 < Aq < A2.

[0028] In some embodiments,

[0029] The first magnetic steel slot comprises a first magnetic steel slot first side, a first magnetic steel slot second side and a first magnetic steel slot third side, the first magnetic steel slot first side is towards the center line, the first magnetic steel slot second side is located on the radial inner side of the first magnetic steel slot first side and opposite to the second magnetic steel slot, and the first magnetic steel slot third side is located on the radial inner side of the first magnetic steel slot first side and opposite to the fifth magnetic steel slot; the second magnetic steel slot comprises a second magnetic steel slot first side, a second magnetic steel slot second side and a second magnetic steel slot third side, the second magnetic steel slot first side is towards the center line, the second magnetic steel slot second side is located on the radial inner side of the second magnetic steel slot first side and opposite to the first magnetic steel slot, and the second magnetic steel slot third side is located on the radial inner side of the second magnetic steel slot first side and opposite to the fifth magnetic steel slot;

[0030] The third magnetic steel slot comprises a third magnetic steel slot first side, a third magnetic steel slot second side and a third magnetic steel slot third side, the third magnetic steel slot first side is towards the first magnetic steel slot, the third magnetic steel slot second side is located on the radial inner side of the third magnetic steel slot first side and opposite to the fifth magnetic steel slot, and the third magnetic steel slot third side is opposite to the third magnetic steel slot first side; the fourth magnetic steel slot comprises a fourth magnetic steel slot first side, a fourth magnetic steel slot second side and a fourth magnetic steel slot third side, the fourth magnetic steel slot first side is towards the second magnetic steel slot, the fourth magnetic steel slot second side is located on the radial inner side of the fourth magnetic steel slot first side and opposite to the fifth magnetic steel slot, and the fourth magnetic steel slot third side is opposite to the fourth magnetic steel slot first side;

[0031] The fifth magnetic steel slot comprises a fifth magnetic steel slot first side located on the radial outer end and intersecting with the center line, a fifth magnetic steel slot second side opposite to the third magnetic steel slot second side, a fifth magnetic steel slot third side opposite to the fourth magnetic steel slot second side and a fifth magnetic steel slot fourth side located on the radial inner side and intersecting with the center line;

[0032] The first magnetic steel slot first side is connected with the first magnetic steel slot second side, and the second magnetic steel slot first side is connected with the second magnetic steel slot second side; the first magnetic steel slot second side and the first magnetic steel slot third side are connected through an arc segment, and the second magnetic steel slot second side and the second magnetic steel slot third side are connected through an arc segment;

[0033] The third magnetic steel slot first side and the third magnetic steel slot second side are connected through an arc segment, and the fifth magnetic steel slot first side and the fifth magnetic steel slot second side are connected through an arc segment; the third magnetic steel slot third side and the third magnetic steel slot second side are connected through an arc segment, and the fifth magnetic steel slot second side and the fifth magnetic steel slot fourth side are connected through an arc segment;

[0034] The first edge of the fourth magnetic steel groove and the second edge of the fourth magnetic steel groove are connected by an arc segment, the first edge of the fifth magnetic steel groove and the third edge of the fifth magnetic steel groove are connected by an arc segment; the third edge of the fourth magnetic steel groove and the second edge of the fourth magnetic steel groove are connected by an arc segment, and the third edge of the fifth magnetic steel groove and the fourth edge of the fifth magnetic steel groove are connected by an arc segment.

[0035] In some embodiments,

[0036] The intersection between the line connecting the intersection point of the first edge of the first magnetic steel groove and the second edge of the first magnetic steel groove and the intersection point of the first edge of the second magnetic steel groove and the second edge of the second magnetic steel groove and the center line intersects at Q1a.

[0037] The intersection between the intersection point of the extension line of the second edge of the first magnetic steel groove and the extension line of the third edge of the first magnetic steel groove and the intersection point of the extension line of the second edge of the second magnetic steel groove and the extension line of the third edge of the second magnetic steel groove and the center line intersects at Q1b.

[0038] The intersection between the intersection point of the extension line of the first edge of the third magnetic steel groove and the extension line of the second edge of the third magnetic steel groove and the intersection point of the extension line of the first edge of the fifth magnetic steel groove and the extension line of the second edge of the fifth magnetic steel groove and the width center line of the second magnetic bridge intersects at Q2a; the intersection between the intersection point of the extension line of the third edge of the third magnetic steel groove and the extension line of the second edge of the third magnetic steel groove and the intersection point of the extension line of the second edge of the fifth magnetic steel groove and the extension line of the fourth edge of the fifth magnetic steel groove and the width center line of the second magnetic bridge intersects at Q2b.

[0039] The intersection between the intersection point of the extension line of the first edge of the fourth magnetic steel groove and the extension line of the second edge of the fourth magnetic steel groove and the intersection point of the extension line of the first edge of the fifth magnetic steel groove and the extension line of the third edge of the fifth magnetic steel groove and the width center line of the third magnetic bridge intersects at Q3a; the intersection between the intersection point of the extension line of the third edge of the fourth magnetic steel groove and the extension line of the second edge of the fourth magnetic steel groove and the intersection point of the extension line of the third edge of the fifth magnetic steel groove and the extension line of the fourth edge of the fifth magnetic steel groove and the width center line of the third magnetic bridge intersects at Q3b.

[0040] In some embodiments,

[0041] Aq=67.5deg, the radius of all arc segments is 0.8-1.5mm, the first air groove and the second air groove are rectangular structures, the length L is 14-16mm, and the length direction is perpendicular to the width direction.

[0042] The application also provides a permanent magnet auxiliary synchronous reluctance motor comprising the permanent magnet auxiliary synchronous reluctance motor rotor structure.

[0043] The permanent magnet auxiliary synchronous reluctance motor rotor structure and the permanent magnet auxiliary synchronous reluctance motor have the following beneficial effects:

[0044] 1. The width B of the air slot in the circumferential direction and the width w1 of the first magnetic isolation bridge in the circumferential direction are set to satisfy the constraint relationship: B = (3.5-3.7) x 10^8 / (w1*nmax^2), wherein nmax is the highest design speed of the motor, which can effectively limit the width range of the air slot, and the intersection point of the connecting line between the end of the first air slot closest to the center line and the end of the second air slot closest to the center line and the center line is P, the radial outer end of the N-level first magnetic isolation bridge Q1 intersects the center line, and the ratio MN / MP of the distance MN to the distance MP satisfies MN / MP = 0.5-0.52, which can effectively limit the radial position of the air slot, so that the size and position relationship of the air slot are limited by the above two aspects, so that the air slot is not too close to the radial outer side to affect the electromagnetic performance, and the air slot is not too close to the radial inner side to cause the centrifugal force of the rotor to be too high. While reducing the large centrifugal force generated during high-speed rotation, the electromagnetic performance is also effectively ensured, the centrifugal force of the core during rotation is reduced, the stress of the magnetic isolation bridge is reduced, and the problem that the rotor core of the permanent magnet auxiliary synchronous reluctance motor is subjected to a large centrifugal force during high-speed rotation, resulting in a large stress on the magnetic isolation bridge and low mechanical strength of the rotor, is solved.

[0045] 2. The shortest distance x between the first air slot and the first magnetic steel slot in the circumferential direction is set to satisfy 3-3.3 mm, which can limit the distance between the first magnetic steel slot and the first air slot from being too close, the edge of the first air slot facing the center line is the first air slot first edge, the edge of the second air slot facing the center line is the second air slot first edge, and the included angle between the first air slot first edge and the second air slot first edge is Ak, Ak has a value range: Ak = 360deg / poles ± 2deg, which can limit the included angle between the two air slots, so that the air slots and the magnetic steel slots are as parallel as possible to prevent being too close (small gap, high magnetic density, and low output), and can also prevent being too far apart. The main purpose is to prevent being too close. Therefore, the range of the above X and Ak can limit the distance between the air slot and the magnetic steel slot from being too small, thereby preventing magnetic density saturation and magnetic chain drop, reducing harmonic content, and improving electromagnetic performance.

[0046] 3. The application also sets the relationship between the width w2 of the second and third magnetic isolation bridges and the width w1 of the first magnetic isolation bridge to satisfy W2-w1=0.2-0.4mm, so as to make the width of the second and third magnetic isolation bridges as large as possible, because the stress on the second and third magnetic isolation bridges is greater than that on the middle (first) magnetic isolation bridge, so increasing the width can reduce the stress and make the stress as uniform as possible; and avoid deformation caused by excessive stress on a certain magnetic isolation bridge;

[0047] 4. The application also sets the angle between the line connecting Q1a and Q2b and the line connecting Q1a and Q3b to be A1, the angle between the line connecting Q1b and Q2a and the line connecting Q1b and Q3a to be A2, and the angle between the width center line of the second magnetic isolation bridge and the width center line of the third magnetic isolation bridge to be Aq, and A1, A2 and Aq have a constraint relationship: A1<Aq<A2, so as to make the intersection of the center lines of the second and third magnetic isolation bridges be located in the region between the upper and lower ends of the first magnetic isolation bridge, so that the stress direction of the magnetic isolation bridges Q2 and Q3 is parallel to the center line of the magnetic isolation bridge, and the magnetic isolation bridges Q2 and Q3 only bear tensile stress, so that the stress on the magnetic isolation bridges is more uniform. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0049] Figure 2 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0050] Figure 3 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0051] Figure 4 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0052] Figure 5 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0053] Figure 6 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0054] Figure 7 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0055] Figure 8 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0056] Figure 9 is one of the schematic diagrams of the rotor structure of the permanent magnet auxiliary synchronous reluctance motor of the application;

[0057] Figure 10 Figure 2 is a second partial enlarged view of the magnetic isolation bridge of the rotor structure of the present application.

[0058] Figure 11 Figure 3 is a comparison diagram of the present application and the conventional rotor core stress simulation;

[0059] Figure 12 Figure 4 is a stress distribution diagram of the magnetic isolation bridge of the rotor core of the present application (the stress of the magnetic isolation bridge is more uniform);

[0060] Figure 13 Figure 5 is a comparison diagram of the present application and the conventional rotor core stress simulation at the magnetic isolation bridge.

[0061] Reference signs are as follows:

[0062] 1, rotor core; 2, magnetic steel slot; 21, first magnetic steel slot; 22, second magnetic steel slot; 23, third magnetic steel slot; 24, fourth magnetic steel slot; 25, fifth magnetic steel slot; 3, magnetic steel; 31, first magnetic steel; 32, second magnetic steel; 33, third magnetic steel; 34, fourth magnetic steel; 35, fifth magnetic steel; 4, air slot; 41, first air slot; 42, second air slot;

[0063] I, center line; Q1, first magnetic isolation bridge; Q2, second magnetic isolation bridge; Q3, third magnetic isolation bridge; 211, first magnetic steel slot first side; 212, first magnetic steel slot second side; 213, first magnetic steel slot third side; 221, second magnetic steel slot first side; 222, second magnetic steel slot second side; 223, second magnetic steel slot third side; 231, third magnetic steel slot first side; 232, third magnetic steel slot second side; 233, third magnetic steel slot third side; 241, fourth magnetic steel slot first side; 242, fourth magnetic steel slot second side; 243, fourth magnetic steel slot third side; 251, fifth magnetic steel slot first side; 252, fifth magnetic steel slot second side; 253, fifth magnetic steel slot third side; 254, fifth magnetic steel slot fourth side; 411, first air slot first side; 412, first air slot second side; 421, second air slot first side; 422, second air slot second side;

[0064] O, rotor center point; P, end point of the first magnetic isolation bridge close to one side of the rotor outer edge; N, intersection of the connecting line of the top points of the first air slot and the second air slot close to the center line and the center line; M, intersection of the center line and the rotor outer edge; Ak, included angle between the first air slot first side and the second air slot first side; B, width of the air slot; L, length of the air slot; x, shortest distance between the first air slot and the first magnetic steel slot; w1, width of the first magnetic isolation bridge Q1; w2, width of the second magnetic isolation bridge Q2 and the third magnetic isolation bridge Q3; Aq, included angle between the center line of the second magnetic isolation bridge Q2 and the center line of the third magnetic isolation bridge Q3;

[0065] Q1a, end point of the first magnetic isolation bridge close to the side of the rotor outer edge; Q1b, end point of the first magnetic isolation bridge close to the center point of the rotor; Q2a, end point of the second magnetic isolation bridge close to the side of the center line I; Q2b, end point of the second magnetic isolation bridge away from the side of the rotor center line I; Q3a, end point of the third magnetic isolation bridge close to the side of the center line I; Q3b, end point of the third magnetic isolation bridge away from the side of the rotor center line I; A1, included angle between straight line Q1a, Q2b and straight line Q1a, Q3b; A2, included angle between straight line Q1b, Q2a and straight line Q1b, Q3a. DETAILED DESCRIPTION

[0066] 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 a part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not intended to limit the present application and its application or use in any way. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0067] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and it should also be understood that when the terms "comprise" and / or "include" are used in the specification, there is a reference to the presence of a feature, step, operation, device, component and / or combinations thereof.

[0068] The relative arrangement of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present application, unless otherwise specifically stated. At the same time, it should be understood that the sizes of the various parts shown in the drawings are not drawn in proportion to the actual proportions. The techniques, methods and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the authorized specification, if appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Therefore, other examples of exemplary embodiments can have different values. It should be noted that similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0069] In the description of the application, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or position relationship is generally based on the orientation or position relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0070] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial position relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0071] In addition, it should be noted that the use of "first", "second" and the like to define parts has only the purpose of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0072] As Figures 1-13 shown, the application provides a permanent magnet auxiliary synchronous reluctance motor rotor structure, which comprises:

[0073] A rotor core 1 having multiple magnetic poles. Within any magnetic pole and within an axial projection plane, the rotor core 1 has a centerline I extending radially outward from the center of the rotor core 1 and intersecting the radial outer periphery of the rotor core 1 at a point M. The rotor core 1 is provided with at least two air slots 4, including a first air slot 41 and a second air slot 42. The first air slot 41 and the second air slot 42 are symmetrically arranged relative to the centerline I. The rotor core 1 is provided with at least two magnetic steel slots 2, including a first magnetic steel slot 21 closest to the first air slot 41 and a second magnetic steel slot 22 closest to the second air slot 42. The first magnetic steel slot 21 and the second magnetic steel slot 22 are also symmetrically arranged relative to the centerline I.

[0074] The width of the air slot 4 along the circumferential direction is B, and the cavity on the radial inner side of the first magnetic steel slot 21 (ie Figures 3-4 As shown, the cavity is part of the first magnetic steel slot, which is a triangular area located at the radial innermost side) and the cavity on the radial inner side of the second magnetic steel slot 22 (i.e. Figures 3-4 As shown, the cavity belongs to a part of the second magnetic steel slot, which is an approximately triangular area located at the radial innermost side) and is the first magnetic isolation bridge Q1. The width of the first magnetic isolation bridge Q1 is w1 (the width is the minimum distance between the two opposite sides of the first and second magnetic steel slots. Preferably, the two opposite sides of the two magnetic steel slots are parallel, so the minimum distances at different positions are the same, so the width w1 is certain). There is a constraint relationship: B = (3.5~3.7)×10^8 / (w1*nmax^2), where nmax is the maximum design speed of the motor, the intersection point of the connecting line between the end of the first air slot 41 closest to the center line and the end of the second air slot 22 closest to the center line and the center line I is N, and the radial outer end of the first magnetic isolation bridge Q1 intersects with the center line I at P, where the ratio of the distance MN to the distance MP is MN / MP = 0.5~0.52.

[0075] The application can effectively limit the width range of the air slot by setting the circumferential width B of the air slot and the circumferential width w1 of the first magnetic isolation bridge to satisfy the constraint relationship: B=(3.5-3.7)*10^8 / (w1*nmax^2), wherein nmax is the highest design rotating speed of the motor, and can effectively limit the radial position of the air slot by setting the intersection of the connecting line between the end of the first air slot closest to the center line and the end of the second air slot closest to the center line and the center line as the radially outer end of the N-level first magnetic isolation bridge Q1 intersecting with the center line as P, and satisfying the ratio MN / MP=0.5-0.52 of the distance MN of the intersection to the distance MP of the intersection, so that the size and position relationship of the air slot are jointly limited by the above two aspects, so that the air slot is not too close to the radially outer side to affect the electromagnetic performance, and the air slot is not too close to the radially inner side to cause the centrifugal force of the rotor to be too high, the electromagnetic performance is effectively ensured while the centrifugal force generated during high-speed rotation is reduced, the centrifugal force of the rotor core is reduced, the stress of the magnetic isolation bridge is reduced, and the problem that the rotor core of the permanent magnet auxiliary synchronous reluctance motor is subjected to a large centrifugal force during high-speed rotation, the stress on the magnetic isolation bridge is large, and the mechanical strength of the rotor is low is solved.

[0076] The application solves the mechanical strength problem of the permanent magnet auxiliary synchronous reluctance motor rotor under high-speed working condition from two aspects of reducing the centrifugal force of the rotor core and reducing the maximum stress value on the magnetic isolation bridge by designing the magnetic isolation bridge and the air slot on the rotor core.

[0077] The improvement points of the application are as follows:

[0078] 1. The application is aimed at the problem of insufficient mechanical strength of the permanent magnet auxiliary synchronous reluctance motor rotor under high-speed working condition, and a 3-4.5t logistics vehicle motor is designed by designing the magnetic isolation bridge and the air slot on the rotor core, the motor stator outer diameter is 230mm, the peak power is 70Kw-80Kw, the peak torque is 200Nm-300Nm, and the peak rotating speed is 9000rpm-12000rpm. The air slot on the rotor structure is designed, the centrifugal force of the rotor core during high-speed rotation is greatly reduced, the stress on the magnetic isolation bridge is reduced, and the mechanical strength of the rotor is improved.

[0079] 2. By designing the magnetic isolation bridge, the stress on the magnetic isolation bridge mainly bearing the centrifugal force is more uniform, the problem that the local stress of a certain magnetic isolation bridge is too large due to uneven stress on the magnetic isolation bridge, resulting in excessive deformation of the rotor core is avoided, the problem that the local stress of the magnetic isolation bridge is increased due to the combined action of stretching and bending of the magnetic isolation bridge is solved, the mechanical strength of the rotor is improved, the reliability of the motor is improved, and the electromagnetic performance and torque output capacity of the motor are ensured.

[0080] The following technical problems are solved:

[0081] 1. greatly reduce the centrifugal force on the rotor core when rotating at high speed, reduce the stress on the magnetic bridge, and improve the mechanical strength of the rotor;

[0082] 2. ensure the output torque of the motor, reduce the harmonic content of the motor, and reduce the torque ripple of the motor;

[0083] 3. solve the problem of insufficient mechanical strength of the rotor of the permanent magnet auxiliary synchronous reluctance motor under high-speed working conditions; (achieved by reducing stress);

[0084] 4. solve the problem of excessive deformation of the rotor core caused by uneven stress on the magnetic bridge;

[0085] 5. solve the problem of increased local stress on the magnetic bridge caused by the combined action of stretching and bending of the magnetic bridge.

[0086] In some embodiments,

[0087] B = 4.5 / w1, w1 = 1.5-2mm. This is a further preferred relationship between the air slot width and the first magnetic bridge width w1 of the present application, which further reduces the large centrifugal force generated when rotating at high speed while effectively ensuring electromagnetic performance, reduces the centrifugal force when the core rotates, reduces the stress on the magnetic bridge, and solves the problem of the rotor core of the permanent magnet auxiliary synchronous reluctance motor being subjected to a large centrifugal force when rotating at high speed, resulting in a large stress on the magnetic bridge and a low mechanical strength of the rotor.

[0088] In some embodiments,

[0089] w1 = 1.8mm, nmax = 9000rpm, MN / MP = 0.515. This is a further preferred width of the air slot, a preferred motor speed, and a preferred ratio of MN / MP of the present application, which further reduces the large centrifugal force generated when rotating at high speed while effectively ensuring electromagnetic performance, reduces the centrifugal force when the core rotates, reduces the stress on the magnetic bridge, and solves the problem of the rotor core of the permanent magnet auxiliary synchronous reluctance motor being subjected to a large centrifugal force when rotating at high speed, resulting in a large stress on the magnetic bridge and a low mechanical strength of the rotor.

[0090] In some embodiments,

[0091] The first air slot 41 and the first magnetic steel slot 21 are located on the same side of the center line I, and the shortest distance between the first air slot 41 and the first magnetic steel slot 21 along the circumference is x, x is in the range of 3-3.3mm, the side of the first air slot 41 facing the center line I is the first air slot first side 411, the side of the second air slot 42 facing the center line I is the second air slot first side 421, and the included angle between the first air slot first side 411 and the second air slot first side 421 is Ak, Ak is in the range of Ak=360deg / poles±2deg, poles is the number of poles, and deg is the degree of angle.

[0092] The present application also sets the shortest distance x between the first air slot and the first magnetic steel slot along the circumference to be in the range of 3-3.3mm, so that the distance between the first magnetic steel slot and the first air slot is not too close, the side of the first air slot facing the center line is the first air slot first side, the side of the second air slot facing the center line is the second air slot first side, and the included angle between the first air slot first side and the second air slot first side is Ak, Ak is in the range of Ak=360deg / poles±2deg, so that the included angle between the two air slots is limited, so that the air slot and the magnetic steel slot are as parallel as possible, preventing them from being too close (small gap, high magnetic density, and low output), and preventing them from being too far apart, mainly preventing them from being too close. Therefore, the range of the above X and Ak limits the distance between the air slot and the magnetic steel slot to be not too small, thereby preventing magnetic density saturation and magnetic chain drop, reducing harmonic content, and improving electromagnetic performance.

[0093] In some embodiments,

[0094] x=3.14mm; Ak=360deg / poles, poles is 8. This is the preferred value of the shortest distance x between the first air slot and the first magnetic steel slot along the circumference of the present application, as well as the preferred value of Ak and the number of poles, which can further limit the distance between the air slot and the magnetic steel slot to be not too small, thereby preventing magnetic density saturation and magnetic chain drop, reducing harmonic content, and improving electromagnetic performance.

[0095] The invention point of the present application includes air slot design and magnetic bridge design, and the improvement point one is:

[0096] 1. Air slot design. The air slot length is L, L is in the range of 14-16mm, preferably L=14.5mm; the air slot width is B, the first magnetic isolation bridge Q1 width is w1, the second magnetic isolation bridge Q2, the third magnetic isolation bridge Q3 width is w2, wherein there is a constraint relationship: B=(3.5-3.7)×10^8 / (w1*nmax^2), preferably B=4.5 / w1, and w1=1.5-2mm, preferably w1=1.8mm; the intersection of the center line and the outer edge of the rotor is M, the intersection of the vertex connecting line of the first air slot and the second air slot close to the center line and the center line is N, and the endpoint of the first magnetic isolation bridge Q1 close to the outer edge of the rotor is P, wherein the ratio of the distance between MN and the distance between MP is 0.5-0.52, preferably 0.515. The above constraint relationship can greatly reduce the centrifugal force on the rotor core when rotating at high speed, reduce the stress on the magnetic isolation bridge, thereby improving the mechanical strength of the rotor and the reliability of the motor. The shortest distance between the first air slot and the first magnetic steel slot is x, x is in the range of 3-3.3mm, preferably x=3.14mm; the included angle between the first side 411 of the first air slot and the first side 421 of the second air slot is Ak, Ak is in the range of Ak=360deg / poles±2deg, (poles is the number of poles, this case is 8), preferably Ak=360deg / poles. The distance x and the included angle Ak can avoid the rotor core from appearing magnetic density saturation and magnetic chain drop, and can also reduce the harmonic content of the motor and improve the electromagnetic performance of the rotor.

[0097] In some embodiments,

[0098] The magnetic steel slot 2 also includes a third magnetic steel slot 23 located on the circumferential side of the first magnetic steel slot 21 away from the center line I, and a fourth magnetic steel slot 24 located on the circumferential side of the second magnetic steel slot 22 away from the center line I, and the magnetic steel slot 2 also includes a fifth magnetic steel slot 25 located on the radially inner side of the first magnetic steel slot 21 and the second magnetic steel slot 22, and the third magnetic steel slot 23 and the fourth magnetic steel slot 24 are also symmetrically arranged relative to the center line I, and the fifth magnetic steel slot 25 is also symmetric relative to the center line I.

[0099] This is the preferred structure of the third magnetic steel slot, the fourth magnetic steel slot and the fifth magnetic steel slot of the present application, and the magnetic steel can be arranged in the third and fourth magnetic steel slots and the fifth magnetic steel slot, further improving the electromagnetic performance of the rotor core.

[0100] Figure 1 The rotor structure of the present application is shown in the figure, and the rotor core 1 has a magnetic steel slot 2, a magnetic steel 3, and an air slot 4. The magnetic steel 3 is installed in the magnetic steel slot 2, and the magnetic steel slot is connected to the magnetic steel slot or the magnetic steel slot and the outer edge of the rotor core to form a magnetic isolation bridge. Figure 1This is a schematic diagram of one-eighth of the rotor structure of the proposed invention, which is a magnetic pole of the rotor of the proposed invention. Its structure is symmetrical about the center line I.

[0101] The magnetic steel slot 2 includes a first magnetic steel slot 21, a second magnetic steel slot 22, a third magnetic steel slot 23, a fourth magnetic steel slot 24, and a fifth magnetic steel slot 25. The magnetic steel 3 includes a first magnetic steel 31, a second magnetic steel 32, a third magnetic steel 33, a fourth magnetic steel 34, and a fifth magnetic steel 35. The air slot includes a first air slot 41 and a second air slot 42. The first magnetic steel 31, the second magnetic steel 32, the third magnetic steel 33, the fourth magnetic steel 34, and the fifth magnetic steel 35 are respectively installed in the first magnetic steel slot 21, the second magnetic steel slot 22, the third magnetic steel 33, the fourth magnetic steel 34, and the fifth magnetic steel 35. The third magnetic steel slot 23, the fourth magnetic steel slot 24, and the fifth magnetic steel slot 25 form the first layer, the first magnetic steel slot 21 and the second magnetic steel slot 22 form the second layer, and the first air slot 41 and the second air slot 42 form the third layer. The three layers form a "UVV" structure.

[0102] In some embodiments,

[0103] The cavity on the radial inner side of the third magnetic steel slot 23 (i.e. Figures 3-4 As shown, the cavity is part of the third magnetic steel slot and is an approximately triangular area located at the innermost radial side. The cavity is separated from the fifth magnetic steel slot 25 closest to the third magnetic steel slot 23 by a second magnetic isolation bridge Q2. The cavity on the radial inner side of the fourth magnetic steel slot 24 (i.e., Figures 3-4 As shown, the cavity is part of the fourth magnetic steel slot and is a substantially triangular area located radially innermost. The cavity is separated from the fifth magnetic steel slot 25 closest to the fourth magnetic steel slot 24 by a third magnetic isolation bridge Q3. The widths of the second magnetic isolation bridge Q2 and the third magnetic isolation bridge Q3 are both w2 (the width of the second magnetic isolation bridge Q2 is the minimum distance between the two opposite sides of the third and fifth magnetic steel slots. Preferably, the two opposite sides of the third and fifth magnetic steel slots are parallel, so the width w2 is constant. The width of the third magnetic isolation bridge Q3 is the minimum distance between the two opposite sides of the fourth and fifth magnetic steel slots. Preferably, the two opposite sides of the fourth and fifth magnetic steel slots are parallel, so the width w3 is constant).

[0104] And there is a constraint relationship: w2-w1=0.2-0.4mm.

[0105] The present invention also makes the widths of the second and third magnetic isolation bridges as large as possible by setting the relationship between the width w2 of the second magnetic isolation bridge and the third magnetic isolation bridge and the width w1 of the first magnetic isolation bridge to satisfy W2-w1=0.2-0.4mm. Because the stress on the second and third magnetic isolation bridges is greater than the stress on the middle (first) magnetic isolation bridge, the width is increased and the stress on them is reduced, so that the stress is made as uniform as possible, thereby avoiding deformation caused by excessive stress on a certain magnetic isolation bridge.

[0106] In some embodiments,

[0107] In the projection plane of the axial end surface of the rotor core 1: the first flux barrier Q1 is a rectangular structure, the edge of the first flux barrier Q1 on the radial outer side intersects the center line I at Q1a, and the edge of the first flux barrier Q1 on the radial inner side intersects the center line I at point Q1b;

[0108] The second flux barrier Q2 is a rectangular structure, the length midpoint of the edge of the second flux barrier Q2 closest to the center line I is Q2a, and the length midpoint of the edge of the second flux barrier Q2 farthest from the center line I is Q2b;

[0109] The third flux barrier Q3 is a rectangular structure, the length midpoint of the edge of the third flux barrier Q3 closest to the center line I is Q3a, and the length midpoint of the edge of the third flux barrier Q3 farthest from the center line I is Q3b; the angle between the line connecting Q1a and Q2b and the line connecting Q1a and Q3b is A1, the angle between the line connecting Q1b and Q2a and the line connecting Q1b and Q3a is A2; the angle between the width center line of the second flux barrier Q2 and the width center line of the third flux barrier Q3 is Aq, and A1, A2 and Aq exist the constraint relationship: A1<Aq<A2.

[0110] The present application also has the intersection point of the center line of the second and third flux barriers located in the region between the upper and lower ends of the first flux barrier, so that the stress direction of the flux barriers Q2 and Q3 is parallel to the center line of the flux barriers, the flux barriers Q2 and Q3 only bear tensile stress, and the stress of the flux barriers is more uniform. Figure 13 The traditional figure of the present application is subjected to tensile force and bending stress, and the two circles are the maximum stress positions), the stress of the four circles of the present application is almost the same, and the effect of uniform stress distribution is achieved.

[0111] The second improvement of the present application:

[0112] 2. The magnetic bridge design. The first magnetic bridge Q1 width w1 and the second magnetic bridge Q2, the third magnetic bridge Q3 width w2, there is a constraint relationship: W2-w1=0.2-0.4mm, the constraint relationship can make the stress of the above three magnetic bridges consistent, as shown in the figure, avoid some magnetic bridge to receive stress too large lead to rotor core excessive deformation, so that the rotor rubs the edge of the abnormal, affect the reliability of the motor. By the design of the middle line angle Aq of the magnetic bridge Q2, Q3, the stress direction of the magnetic bridge Q2, Q3 is parallel to the middle line of the magnetic bridge, and the magnetic bridge Q2, Q3 only receives tensile stress, so that the stress of the magnetic bridge is more uniform. Otherwise, the stress direction of the magnetic bridge Q2, Q3 is not parallel to the middle line of the magnetic bridge, and the magnetic bridge will be subjected to tensile and bending interaction, which will lead to the stress of the local position of the magnetic bridge Q2, Q3 to increase greatly. Reduce the maximum stress on the magnetic bridge, thereby improving the mechanical strength of the rotor, improving the reliability of the motor, ensuring the electromagnetic performance, torque output capacity of the motor.

[0113] In some embodiments,

[0114] The first magnetic steel slot 21 includes a first magnetic steel slot first edge 211, a first magnetic steel slot second edge 212, and a first magnetic steel slot third edge 213, the first magnetic steel slot first edge 211 is towards the center line I, the first magnetic steel slot second edge 212 is located on the inner side of the first magnetic steel slot first edge 211 and opposite to the second magnetic steel slot 22, and the first magnetic steel slot third edge 213 is located on the inner side of the first magnetic steel slot first edge 211 and opposite to the fifth magnetic steel slot 25; the second magnetic steel slot 22 includes a second magnetic steel slot first edge 221, a second magnetic steel slot second edge 222, and a second magnetic steel slot third edge 223, the second magnetic steel slot first edge 221 is towards the center line I, the second magnetic steel slot second edge 222 is located on the inner side of the second magnetic steel slot first edge 221 and opposite to the first magnetic steel slot 21, and the second magnetic steel slot third edge 223 is located on the inner side of the second magnetic steel slot first edge 221 and opposite to the fifth magnetic steel slot 25;

[0115] The third magnetic steel slot 23 comprises a third magnetic steel slot first edge 231, a third magnetic steel slot second edge 232 and a third magnetic steel slot third edge 233, the third magnetic steel slot first edge 231 is towards the first magnetic steel slot 21, the third magnetic steel slot second edge 232 is located on the radial inner side of the third magnetic steel slot first edge 231 and opposite to the fifth magnetic steel slot 25, and the third magnetic steel slot third edge 233 is opposite to the third magnetic steel slot first edge 231; the fourth magnetic steel slot 24 comprises a fourth magnetic steel slot first edge 241, a fourth magnetic steel slot second edge 242 and a fourth magnetic steel slot third edge 243, the fourth magnetic steel slot first edge 241 is towards the second magnetic steel slot 22, the fourth magnetic steel slot second edge 242 is located on the radial inner side of the fourth magnetic steel slot first edge 241 and opposite to the fifth magnetic steel slot 25, and the fourth magnetic steel slot third edge 243 is opposite to the fourth magnetic steel slot first edge 241;

[0116] The fifth magnetic steel slot 25 comprises a fifth magnetic steel slot first edge 251 located at the radial outer end and intersecting the center line I, a fifth magnetic steel slot second edge 252 opposite to the third magnetic steel slot second edge 232, a fifth magnetic steel slot third edge 253 opposite to the fourth magnetic steel slot second edge 242, and a fifth magnetic steel slot fourth edge 254 located on the radial inner side and intersecting the center line I;

[0117] The first magnetic steel slot first edge 211 is connected with the first magnetic steel slot second edge 212, and the second magnetic steel slot first edge 221 is connected with the second magnetic steel slot second edge 222; the first magnetic steel slot second edge 212 is connected with the first magnetic steel slot third edge 213 through an arc segment, and the second magnetic steel slot second edge 222 is connected with the second magnetic steel slot third edge 223 through an arc segment;

[0118] The third magnetic steel slot first edge 231 is connected with the third magnetic steel slot second edge 232 through an arc segment, and the fifth magnetic steel slot first edge 251 is connected with the fifth magnetic steel slot second edge 252 through an arc segment; the third magnetic steel slot third edge 233 is connected with the third magnetic steel slot second edge 232 through an arc segment, and the fifth magnetic steel slot second edge 252 is connected with the fifth magnetic steel slot fourth edge 254 through an arc segment;

[0119] The fourth magnetic steel slot first edge 241 is connected with the fourth magnetic steel slot second edge 242 through an arc segment, and the fifth magnetic steel slot first edge 251 is connected with the fifth magnetic steel slot third edge 253 through an arc segment; the fourth magnetic steel slot third edge 243 is connected with the fourth magnetic steel slot second edge 242 through an arc segment, and the fifth magnetic steel slot third edge 253 is connected with the fifth magnetic steel slot fourth edge 254 through an arc segment.

[0120] This is the preferred structure of the first, second, third, fourth and fifth magnetic steel slot of the application. By forming a structure with multiple edges, and connecting some adjacent edges with arc segments, the stress at this position can be effectively reduced. The magnetic isolation bridge includes a first magnetic isolation bridge Q1, a second magnetic isolation bridge Q2, and a third magnetic isolation bridge Q3. The edge of the first magnetic steel slot 21 close to the first air slot 41 is the first magnetic steel slot first edge 211, which is connected to the first magnetic steel slot second edge 212 by a circular arc at one end close to the center point. The first magnetic steel slot second edge 212 is connected to the first magnetic steel slot third edge 213 by a circular arc, and the radius of the circular arc is 0.8-1.5mm, preferably 1mm. This circular arc can avoid stress concentration and improve the mechanical strength of the rotor core. The edge of the second magnetic steel slot 22 close to the second air slot 42 is the second magnetic steel slot first edge 221, which is connected to the second magnetic steel slot second edge 222 by a circular arc at one end close to the center point. The second magnetic steel slot second edge 222 is connected to the second magnetic steel slot third edge 223 by a circular arc, and the radius of the circular arc is 0.8-1.5mm, preferably 1mm. This circular arc can avoid stress concentration and improve the mechanical strength of the rotor core. The first magnetic steel slot second edge 212 and the second magnetic steel slot second edge 222 form the first magnetic isolation bridge Q1.

[0121] In some embodiments,

[0122] The intersection between the line connecting the intersection point of the first magnetic steel slot first edge 211 and the first magnetic steel slot second edge 212 and the intersection point of the second magnetic steel slot first edge 221 and the second magnetic steel slot second edge 222 and the center line I is the Q1a;

[0123] The intersection between the line connecting the intersection point of the extension line of the first magnetic steel slot second edge 212 and the extension line of the first magnetic steel slot third edge 213 and the intersection point of the extension line of the second magnetic steel slot second edge 222 and the extension line of the second magnetic steel slot third edge 223 and the center line I is the Q1b;

[0124] The intersection between the line connecting the intersection point of the extension line of the third magnetic steel slot first edge 231 and the extension line of the third magnetic steel slot second edge 232 and the intersection point of the extension line of the fifth magnetic steel slot first edge 251 and the extension line of the fifth magnetic steel slot second edge 252 and the width center line of the second magnetic isolation bridge Q2 is the Q2a; The intersection between the line connecting the intersection point of the extension line of the third magnetic steel slot third edge 233 and the extension line of the third magnetic steel slot second edge 232 and the intersection point of the extension line of the fifth magnetic steel slot second edge 252 and the extension line of the fifth magnetic steel slot fourth edge 254 and the width center line of the second magnetic isolation bridge Q2 is the Q2b;

[0125] The intersection between the extension line of the first edge 241 of the fourth magnetic steel slot and the extension line of the second edge 242 of the fourth magnetic steel slot and the intersection between the extension line of the first edge 251 of the fifth magnetic steel slot and the extension line of the third edge 253 of the fifth magnetic steel slot intersects with the middle line of the width of the third magnetic bridge Q3 at Q3a; the intersection between the extension line of the third edge 243 of the fourth magnetic steel slot and the extension line of the second edge 242 of the fourth magnetic steel slot and the intersection between the extension line of the third edge 253 of the fifth magnetic steel slot and the extension line of the fourth edge 254 of the fifth magnetic steel slot intersects with the middle line of the width of the third magnetic bridge Q3 at Q3b.

[0126] This is the preferred forming and confirming method of Q1a, Q1b, Q2a, Q2b, Q3a and Q3b of the present application, which can further make the stress direction of the magnetic bridge Q2 and Q3 parallel to the middle line of the magnetic bridge, and only tensile stress is applied to the magnetic bridge Q2 and Q3, so that the stress applied to the magnetic bridge is more uniform.

[0127] The edge of the third magnetic steel slot 23 close to the first magnetic steel slot 21 is the first edge 231 of the third magnetic steel slot, which is connected to the second edge 232 of the third magnetic steel slot by a circular arc at one end close to the center point. The second edge 232 of the third magnetic steel slot is connected to the third edge 233 of the third magnetic steel slot by a circular arc, and the radius of the circular arc is 0.8-1.5mm, preferably 1mm. The edge of the fourth magnetic steel slot 24 close to the second magnetic steel slot 22 is the first edge 241 of the fourth magnetic steel slot, which is connected to the second edge 242 of the fourth magnetic steel slot by a circular arc at one end close to the center point. The second edge 242 of the fourth magnetic steel slot is connected to the third edge 243 of the fourth magnetic steel slot by a circular arc, and the radius of the circular arc is 0.8-1.5mm, preferably 1mm. The fifth magnetic steel slot 25 is composed of the first edge 251, the second edge 252, the third edge 253 and the fourth edge 254 of the fifth magnetic steel slot, and has the shape of an isosceles trapezoid, and the first edge 251 and the fourth edge 254 of the fifth magnetic steel slot are parallel edges. The edges of the fifth magnetic steel slot are connected by circular arcs, and the radius of the circular arc at both ends of the fourth edge 254 of the fifth magnetic steel slot is 0.8-1.5mm, preferably 1mm. All the above-mentioned circular arcs are the circular arcs at both ends of the magnetic bridge, which can avoid local stress concentration of the magnetic bridge and improve the mechanical strength of the rotor core. The second edge 232 of the third magnetic steel slot and the second edge 252 of the fifth magnetic steel slot form a magnetic bridge Q2, and the second edge 242 of the fourth magnetic steel slot and the third edge 253 of the fifth magnetic steel slot form a magnetic bridge Q3.

[0128] Further explained as follows: Q1a is the intersection between the line connecting the intersection point of the first magnetic steel slot first edge 211 and the first magnetic steel slot second edge 212 and the intersection point of the second magnetic steel slot first edge 221 and the second magnetic steel slot second edge 222 and the center line I; Q1b is the intersection between the line connecting the intersection point of the extension line of the first magnetic steel slot second edge 212 and the first magnetic steel slot third edge 213 and the intersection point of the extension line of the second magnetic steel slot second edge 222 and the second magnetic steel slot third edge 223 and the center line I; Q2a is the intersection between the line connecting the intersection point of the extension line of the third magnetic steel first edge 231 and the third magnetic steel slot second edge 232 and the intersection point of the extension line of the fifth magnetic steel slot first edge 251 and the fifth magnetic steel slot second edge 252 and the middle line of the second magnetic bridge Q2; Q2b is the intersection between the line connecting the intersection point of the extension line of the third magnetic steel second edge 232 and the third magnetic steel slot third edge 233 and the intersection point of the extension line of the fifth magnetic steel slot second edge 252 and the fifth magnetic steel slot fourth edge 254 and the middle line of the second magnetic bridge Q2; Q3a is the intersection between the line connecting the intersection point of the extension line of the fourth magnetic steel first edge 241 and the fourth magnetic steel slot second edge 242 and the intersection point of the extension line of the fifth magnetic steel slot first edge 251 and the fifth magnetic steel slot third edge 253 and the middle line of the third magnetic bridge Q3; Q3b is the intersection between the line connecting the intersection point of the extension line of the fourth magnetic steel second edge 242 and the fourth magnetic steel slot third edge 243 and the intersection point of the extension line of the fifth magnetic steel slot third edge 253 and the fifth magnetic steel slot fourth edge 254 and the middle line of the third magnetic bridge Q3.

[0129] In some embodiments,

[0130] Aq=67.5deg, the radius of all arc segments is 0.8-1.5mm, the first air slot 41 and the second air slot 42 are rectangular structures, the length L is 14-16mm, and the length direction is perpendicular to the width direction.

[0131] The first air slot 41 and the second air slot 42 are rectangular shapes, the edges are connected by circular arcs, the two air slots are symmetrical about the center line I, and the shape is an "eight" character shape, and the opening direction is towards the rotor outer edge. The long edge of the first air slot 41 close to the center line is the first air slot first edge 411, and the long edge parallel to it is the first air slot second edge 412; the long edge of the second air slot 42 close to the center line is the second air slot first edge 421, and the long edge parallel to it is the second air slot second edge 422.

[0132] The application also provides a permanent magnet auxiliary synchronous reluctance motor, which comprises the permanent magnet auxiliary synchronous reluctance motor rotor structure.

[0133] The application is used for 3-4.5t logistics vehicle motors, the motor stator outer diameter is 230mm, the peak power is 70Kw-80Kw, the peak torque is 200Nm-300Nm, and the peak speed is 9000rpm-12000rpm.

[0134] As attached Figure 7 As shown, the length of the air slot of the present invention is L, and the value range of L is 14-16mm, preferably L=14.5mm; the width of the air slot is B, the width of the first magnetic isolation bridge Q1 is w1, and the widths of the second magnetic isolation bridge Q2 and the third magnetic isolation bridge Q3 are w2, wherein there is a constraint relationship: B=4.5 / w1, and w1=1.5-2mm, preferably w1=1.8mm; the intersection of the center line and the outer edge of the rotor is M, the intersection of the vertex connecting line of the first air slot and the second air slot close to the center line and the center line is N, and the endpoint of the first magnetic isolation bridge Q1 close to the outer edge of the rotor is P, wherein the ratio of the distance MN to the distance MP is 0.5~0.52, preferably 0.515. The above constraint relationship can greatly reduce the centrifugal force on the rotor core during high-speed rotation and reduce the stress on the magnetic isolation bridge, as shown in the attached figure. Figure 11 As shown, the mechanical strength of the rotor is improved and the reliability of the motor is improved. The shortest distance between the first air slot and the first magnetic steel slot is x, and the value range of x is 3-3.3mm, preferably x=3.14mm; the angle between the first side 411 of the first air slot and the first side 421 of the second air slot is Ak, and the value range of Ak is: Ak=360deg / poles±2deg, (poles is the number of poles, and the present invention is preferably 8), preferably Ak=360deg / poles. The distance x and the angle Ak can avoid magnetic density saturation and magnetic flux reduction in the rotor core, and can reduce the harmonic content of the motor and improve the electromagnetic performance of the rotor. The width w1 of the first magnetic isolation bridge Q1 and the width w2 of the second magnetic isolation bridge Q2 and the third magnetic isolation bridge Q3 have a constraint relationship: W2-w1=0.2-0.4mm. This constraint relationship can make the stresses on the above three magnetic isolation bridges consistent, as shown in the attached figure. Figure 12 As shown, it is to avoid the situation where a magnetic isolation bridge is subjected to excessive stress, causing excessive deformation of the rotor core, thereby causing abnormal rotor edge rubbing and affecting the reliability of the motor.

[0135] As attached Figure 9As shown, the end point of the first magnetic isolation bridge Q1 close to the outer edge of the rotor is Q1a, and the other end point is Q1b; the end point of the second magnetic isolation bridge Q2 close to the center line I is Q2a, and the other end point is Q2b; the end point of the third magnetic isolation bridge Q3 close to the center line I is Q3a, and the other end point is Q3b; the included angle between the straight line Q1a, Q2b and the straight line Q1a, Q3b is A1, the included angle between the straight line Q1b, Q2a and the straight line Q1b, Q3a is A2; the included angle between the center line of the second magnetic isolation bridge Q2 and the center line of the third magnetic isolation bridge Q3 is Aq, and the included angle Aq has a constraint relationship: A1<Aq<A2, and preferably Aq=67.5deg, which makes the intersection point of the center line of the magnetic isolation bridge Q2 and the center line of the magnetic isolation bridge Q3 between the two ends Q1a and Q1b of the magnetic isolation bridge Q1 on the center line I. The included angle Aq can make the stress direction of the magnetic isolation bridges Q2 and Q3 parallel to the center line of the magnetic isolation bridge, and the magnetic isolation bridges Q2 and Q3 only bear tensile stress, so that the stress of the magnetic isolation bridge is more uniform. Otherwise, the stress direction of the magnetic isolation bridges Q2 and Q3 is not parallel to the center line of the magnetic isolation bridge, and the magnetic isolation bridge will be subjected to the combined action of tension and bending, which will cause the stress of the local position of the magnetic isolation bridges Q2 and Q3 to increase greatly, as shown in the figure. Figure 13 As shown, the motor runs at high speed, the effect of centrifugal force is particularly prominent, far greater than the influence of other forces, and the centrifugal force is proportional to the square of the speed, and the centrifugal force increases greatly with the increase of the speed. The centrifugal force received by the rotor is completely borne by the magnetic isolation bridge, and the maximum stress point often appears on the magnetic isolation bridge. The present application designs the included angle Aq of the center line of the magnetic isolation bridges Q2 and Q3, so that the magnetic isolation bridges Q2 and Q3 bear uniform stress, reduce the maximum stress on the magnetic isolation bridge, thereby improving the mechanical strength of the rotor, improving the reliability of the motor, and ensuring the electromagnetic performance and torque output capacity of the motor.

[0136] The above only describes the preferred embodiments of the present application, and should not be used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application, and should not be used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A permanent magnet assisted synchronous reluctance machine rotor structure, characterized by: The rotor core (1) has a plurality of magnetic poles, in any magnetic pole and in the axial projection plane, the rotor core (1) has a center line (I) extending radially outward from the center of the rotor core (1) and intersecting the radial outer circumference of the rotor core (1) at point M, at least two air slots (4) are provided on the rotor core (1), including a first air slot (41) and a second air slot (42), the first air slot (41) and the second air slot (42) are symmetrically arranged relative to the center line (I), at least two magnetic steel grooves (2) are provided on the rotor core (1), including a first magnetic steel groove (21) closest to the first air slot (41) and a second magnetic steel groove (22) closest to the second air slot (42), the first magnetic steel groove (21) and the second magnetic steel groove (22) are also symmetrically arranged relative to the center line (I); The width of the air slot (4) in the circumferential direction is B, the first magnetic steel groove (21) radially inner side cavity and the second magnetic steel groove (22) radially inner side cavity form a first magnetic bridge (Q1), the width of the first magnetic bridge (Q1) is w1, wherein there is a constraint relationship: B=(3.5-3.7)×10^8 / (w1*nmax^2), wherein nmax is the highest speed of motor design, the intersection of the connecting line between the end of the first air slot (41) closest to the center line and the end of the second air slot (42) closest to the center line and the center line (I) is N, the radial outer side end of the first magnetic bridge Q1 intersects the center line (I) at P, wherein the ratio of the distance MN to the distance MP is MN / MP=0.5-0.

52.

2. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 1, wherein: B=4.5 / w1, w1=1.5-2mm.

3. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 2, wherein: w1=1.8mm, nmax=9000rpm, MN / MP=0.

515.

4. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 1, wherein: The first air slot (41) and the first magnetic steel groove (21) are located on the same side of the center line (I) in the circumferential direction, and the shortest distance between the first air slot (41) and the first magnetic steel groove (21) in the circumferential direction is x, the value of x is 3-3.3mm, the edge of the first air slot (41) facing the center line (I) is the first air slot first edge (411), the edge of the second air slot (42) facing the center line (I) is the second air slot first edge (421), and the included angle between the first air slot first edge (411) and the second air slot first edge (421) is Ak, the value of Ak is Ak=360deg / poles±2deg, poles is the number of poles, and deg is the degree of angle. ​ 5. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 4, characterized in that: x = 3.14 mm; Ak = 360 deg / poles, poles = 8.

6. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to any one of claims 1-5, characterized in that: the magnetic steel slot (2) further comprises a third magnetic steel slot (23) located on the circumferential side of the first magnetic steel slot (21) away from the center line (I), and a fourth magnetic steel slot (24) located on the circumferential side of the second magnetic steel slot (22) away from the center line (I), the magnetic steel slot (2) further comprises a fifth magnetic steel slot (25) located on the radially inner side of the first magnetic steel slot (21) and the second magnetic steel slot (22), the third magnetic steel slot (23) and the fourth magnetic steel slot (24) are also symmetrically arranged relative to the center line (I), and the fifth magnetic steel slot (25) is also symmetric relative to the center line (I).

7. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 6, characterized in that: the cavity radially inside the third magnetic steel slot (23) is separated from the fifth magnetic steel slot (25) closest to the third magnetic steel slot (23) by a second flux barrier (Q2), and the cavity radially inside the fourth magnetic steel slot (24) is separated from the fifth magnetic steel slot (25) closest to the fourth magnetic steel slot (24) by a third flux barrier (Q3); the width of the second flux barrier (Q2) and the third flux barrier (Q3) is w2; and there is a constraint relationship: 0.2mm≤w2-w1≤0.4mm.

8. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 7, characterized in that: in the projection plane of the axial end face of the rotor core (1): the first flux barrier (Q1) is a rectangular structure, the edge of the first flux barrier (Q1) located on the radially outer side intersects the center line (I) at point Q1a, and the edge of the first flux barrier (Q1) located on the radially inner side intersects the center line (I) at point Q1b; the second flux barrier (Q2) is a rectangular structure, the length midpoint of the edge of the second flux barrier (Q2) closest to the center line (I) is Q2a, and the length midpoint of the edge of the second flux barrier (Q2) farthest from the center line (I) is Q2b; the third flux barrier (Q3) is a rectangular structure, the length midpoint of the edge of the third flux barrier (Q3) closest to the center line (I) is Q3a, and the length midpoint of the edge of the third flux barrier (Q3) farthest from the center line (I) is Q3b; the angle between the line connecting Q1a and Q2b and the line connecting Q1a and Q3b is A1, and the angle between the line connecting Q1b and Q2a and the line connecting Q1b and Q3a is A2; the angle between the width center line of the second flux barrier (Q2) and the width center line of the third flux barrier (Q3) is Aq, and A1, A2 and Aq have a constraint relationship: A1<Aq<A2.

9. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 8, characterized in that: The first magnetic steel slot (21) comprises a first magnetic steel slot first edge (211) facing the center line (I), a first magnetic steel slot second edge (212) located radially inside the first magnetic steel slot first edge (211) and opposite the second magnetic steel slot (22), and a first magnetic steel slot third edge (213) located radially inside the first magnetic steel slot first edge (211) and opposite the fifth magnetic steel slot (25); the second magnetic steel slot (22) comprises a second magnetic steel slot first edge (221) facing the center line (I), a second magnetic steel slot second edge (222) located radially inside the second magnetic steel slot first edge (221) and opposite the first magnetic steel slot (21), and a second magnetic steel slot third edge (223) located radially inside the second magnetic steel slot first edge (221) and opposite the fifth magnetic steel slot (25); The third magnetic steel slot (23) comprises a third magnetic steel slot first edge (231) facing the first magnetic steel slot (21), a third magnetic steel slot second edge (232) located radially inside the third magnetic steel slot first edge (231) and opposite the fifth magnetic steel slot (25), and a third magnetic steel slot third edge (233) opposite the third magnetic steel slot first edge (231); the fourth magnetic steel slot (24) comprises a fourth magnetic steel slot first edge (241) facing the second magnetic steel slot (22), a fourth magnetic steel slot second edge (242) located radially inside the fourth magnetic steel slot first edge (241) and opposite the fifth magnetic steel slot (25), and a fourth magnetic steel slot third edge (243) opposite the fourth magnetic steel slot first edge (241); The fifth magnetic steel slot (25) comprises a fifth magnetic steel slot first edge (251) located at a radially outer end and intersecting the center line (I), a fifth magnetic steel slot second edge (252) opposite the third magnetic steel slot second edge (232), a fifth magnetic steel slot third edge (253) opposite the fourth magnetic steel slot second edge (242), and a fifth magnetic steel slot fourth edge (254) located radially inside and intersecting the center line (I); The first magnetic steel slot first edge (211) and the first magnetic steel slot second edge (212) are connected, and the second magnetic steel slot first edge (221) and the second magnetic steel slot second edge (222) are connected; the first magnetic steel slot second edge (212) and the first magnetic steel slot third edge (213) are connected by an arc segment, and the second magnetic steel slot second edge (222) and the second magnetic steel slot third edge (223) are connected by an arc segment; The third magnetic steel slot first edge (231) and the third magnetic steel slot second edge (232) are connected by an arc segment, and the fifth magnetic steel slot first edge (251) and the fifth magnetic steel slot second edge (252) are connected by an arc segment; the third magnetic steel slot third edge (233) and the third magnetic steel slot second edge (232) are connected by an arc segment, and the fifth magnetic steel slot second edge (252) and the fifth magnetic steel slot fourth edge (254) are connected by an arc segment; The fourth magnetic steel slot first edge (241) and the fourth magnetic steel slot second edge (242) are connected by an arc segment, and the fifth magnetic steel slot first edge (251) and the fifth magnetic steel slot third edge (253) are connected by an arc segment; the fourth magnetic steel slot third edge (243) and the fourth magnetic steel slot second edge (242) are connected by an arc segment, and the fifth magnetic steel slot third edge (253) and the fifth magnetic steel slot fourth edge (254) are connected by an arc segment.

10. The permanent magnet auxiliary synchronous reluctance motor rotor structure according to claim 9, characterized in that: The intersection between the line connecting the intersection point of the first magnetic steel slot first edge (211) and the first magnetic steel slot second edge (212) and the intersection point of the second magnetic steel slot first edge (221) and the second magnetic steel slot second edge (222) and the center line (I) intersects the Q1a; The intersection between the line connecting the intersection point of the extension line of the first magnetic steel slot second edge (212) and the extension line of the first magnetic steel slot third edge (213) and the intersection point of the extension line of the second magnetic steel slot second edge (222) and the extension line of the second magnetic steel slot third edge (223) and the center line (I) intersects the Q1b; The intersection between the line connecting the intersection point of the extension line of the third magnetic steel slot first edge (231) and the extension line of the third magnetic steel slot second edge (232) and the intersection point of the extension line of the fifth magnetic steel slot first edge (251) and the extension line of the fifth magnetic steel slot second edge (252) and the width center line of the second magnetic bridge (Q2) intersects the Q2a; the intersection between the line connecting the intersection point of the extension line of the third magnetic steel slot third edge (233) and the extension line of the third magnetic steel slot second edge (232) and the intersection point of the extension line of the fifth magnetic steel slot second edge (252) and the extension line of the fifth magnetic steel slot fourth edge (254) and the width center line of the second magnetic bridge (Q2) intersects the Q2b; The intersection between the line connecting the intersection point of the extension line of the first edge (241) of the fourth magnetic steel slot and the extension line of the second edge (242) of the fourth magnetic steel slot and the intersection point of the extension line of the first edge (251) of the fifth magnetic steel slot and the extension line of the third edge (253) of the fifth magnetic steel slot and the middle line of the width of the third magnetic isolation bridge (Q3) is the Q3a; the intersection between the line connecting the intersection point of the extension line of the third edge (243) of the fourth magnetic steel slot and the extension line of the second edge (242) of the fourth magnetic steel slot and the intersection point of the extension line of the third edge (253) of the fifth magnetic steel slot and the extension line of the fourth edge (254) of the fifth magnetic steel slot and the middle line of the width of the third magnetic isolation bridge (Q3) is the Q3b.

11. The rotor structure of the permanent magnet auxiliary synchronous reluctance motor according to claim 9, characterized in that: Aq=67.5deg, the radius of all the arc segments is 0.8-1.5mm, the first air slot (41) and the second air slot (42) are both rectangular structures, the length L is 14-16mm, and the length direction is perpendicular to the width direction.

12. A permanent magnet assisted synchronous reluctance machine, characterized by: The rotor structure of the permanent magnet auxiliary synchronous reluctance motor according to any one of claims 1-11.

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