A rotor lamination and magnet structure for an electric motor

Abstract

This invention discloses a rotor lamination and magnet structure for an electric motor, relating to the field of motor rotor technology. It includes a rotor core body with U-shaped magnet slots and horizontally shaped magnet slots formed at equal angles within the core body. The U-shaped magnet slots are trapezoidal in shape, narrowing from wide to narrow on both sides, with a uniform-width arc-shaped structure in the middle. The U-shaped magnet slots are used to mount ferrite magnets, while the horizontally shaped magnet slots are used to mount molded neodymium iron boron magnets. This rotor lamination and magnet structure utilizes ferrite magnets, saving significant costs. It features two magnetic barrier bodies on each side of a single pole, improving motor efficiency, reducing air gap magnetic field harmonic content, increasing service life, saving costs, enhancing stability, and offering flexible design to meet the needs of various application scenarios.

Description

Technical Field

[0001] This invention relates to the field of motor rotor technology, specifically to a rotor lamination and magnet structure for a motor. Background Technology

[0002] Rotor laminations and magnets for motors are the core components of the rotor of a permanent magnet synchronous motor. The two work together to achieve efficient energy conversion. The rotor laminations are thin metal sheets made of high magnetic permeability materials (such as silicon steel sheets) and constitute the main structure of the rotor core.

[0003] The announcement number CN215772701U discloses a rotor lamination structure, an electronic rotor, and a motor. Each magnet slot has a magnetic isolation bridge at both ends. The magnetic isolation bridge is a quadrilateral groove. The lamination body is circular, and a rotor shaft hole is provided in the middle of the lamination body. Each magnet slot is formed by two rectangular slots. The long side of each magnetic isolation bridge is set at a first angle with the long side of the rectangular slot connecting the magnetic isolation bridge. By designing a magnetic isolation bridge of a certain size on the rotor lamination, the leakage magnetic effect of the motor during operation can be greatly improved. At the same time, this lamination pattern can achieve the effect of magnetic circuit magnetic bundle sorting, so that the magnetic circuit can be better aligned with the armature direction to improve the magnetic circuit direction.

[0004] However, the rotor lamination structure disclosed above still has the following problems in actual use: the magnets are installed by the magnet slots distributed in a "V" shape. This type of magnet slot adopts a flat bottom slot design. This structure has a poor filling effect when installing magnets, which leads to easy breakage of magnets, low material utilization, and limited space for electromagnetic performance optimization. As a result, it is difficult to significantly improve the power density of the motor and affect the operating efficiency of the electronic rotor.

[0005] Therefore, we propose a rotor lamination and magnet structure for motors to solve the problems mentioned above. Summary of the Invention

[0006] The purpose of this invention is to provide a rotor lamination and magnet structure for an electric motor. This invention addresses the problems of existing magnet installation methods that use "V"-shaped magnet slots with flat-bottomed designs, which result in poor filling during magnet installation, leading to easy magnet breakage, low material utilization, and limited space for electromagnetic performance optimization. Consequently, it is difficult to significantly improve the power density of the electric motor and affect the operating efficiency of the electronic rotor.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a rotor lamination and magnet structure for an electric motor, comprising a rotor core body, wherein U-shaped magnet slots are formed at equal angles inside the rotor core body, and transverse irregular magnet slots are formed at equal angles inside the rotor core body, wherein the transverse irregular magnet slots are located at the center position of the U-shaped magnet slots near the outer side of the rotor core body.

[0008] It also includes: the U-shaped magnetic steel groove opened at equal angles has a trapezoidal structure that narrows from wide to narrow on both sides, and the middle part of the U-shaped magnetic steel groove has an arc-shaped structure of equal width;

[0009] The U-shaped magnet slots, which are opened at equal angles, are used to install ferrite magnets.

[0010] The horizontally shaped magnetic steel groove, which is opened at equal angles, is used to install molded neodymium iron boron magnets.

[0011] Preferably, the width of the two side platforms of the horizontally placed irregularly shaped magnet groove is h1 and the length is L1, and the width of the narrowest part in the middle of the horizontally placed irregularly shaped magnet groove is h2, and the vertical length of the arc of the horizontally placed irregularly shaped magnet groove is L2, and h2 is satisfied.

[0012] Preferably, the width of the wide side of the U-shaped magnet channel is h3, the vertical length of the U-shaped magnet channel is L3, the width of the narrow side of the U-shaped magnet channel is h4, and the arc vertical length of the U-shaped magnet channel is L4, simultaneously satisfying h4. <h3,L4<L3,0.4<h4 / h3<0.6,0.7<L3 / L4<0.9。

[0013] Preferably, the outer diameter of the rotor core body is D2, and the inner diameter of the rotor core body is D3, and D2 is satisfied. COS(α / 2)<D3<D2 COSα, α=360 / P, P is the number of poles of the motor, P=4, 6, 8.

[0014] Preferably, the diameter of the upper middle arc of the U-shaped magnetic groove is D4, and it also satisfies D2. sin <D4<D2 sin(α / 2).

[0015] Preferably, the diameter of the lower middle arc of the U-shaped magnetic groove is D5, and it also satisfies D2. [sin(π / 3) α] <D5<D2 [sin(2π / 3) α].

[0016] ​Preferably, the central angle of the upper middle circle of the U-shaped magnetic steel groove is n1, and the central angle of the lower middle circle of the U-shaped magnetic steel groove is n2, satisfying (n1 / 360°). π D4 < (n2 / 360°) π D5.

[0017] Preferably, the rotor core body has teardrop-shaped weight-reducing holes opened at equal angles inside, and the teardrop-shaped weight-reducing holes are located between the U-shaped magnet slot and the horizontal irregular magnet slot.

[0018] The large circle diameter of the teardrop-shaped weight-reducing hole is r1, and the small circle diameter of the teardrop-shaped weight-reducing hole is r2, satisfying 3. r2<2 r1.

[0019] Preferably, magnetic barrier bodies are respectively provided on both sides of a single stage inside the rotor core body, and the magnetic barrier bodies are symmetrically distributed in pairs about the transverse irregularly shaped magnetic steel slots. The width of the magnetic barrier body near the transverse irregularly shaped magnetic steel slot is h5 and the length is L5, while the width of the magnetic barrier body near the U-shaped magnetic steel slot is h6 and the length is L6, satisfying 0.9. <h5 / h6<1.1,0.9<L5 / L6<1.1。

[0020] Preferably, it satisfies (n1 / 360°). π D4<2 [(h5 L5)+(h6) L6)]<(n2 / 360°) π D5.

[0021] Compared with the prior art, the beneficial effects of the present invention are: the rotor laminations and magnet structure of this motor save a lot of costs by using ferrite magnets; there are two magnetic barrier bodies on each side of a single pole, which improves motor efficiency, reduces the harmonic content of the air gap magnetic field, increases service life, saves costs, improves stability, and provides flexible design to meet the needs of different application scenarios. The specific details are as follows:

[0022] 1. The circular slots at the four sharp corners of the horizontally placed irregularly shaped magnet slot are used to prevent magnetic leakage. Compared with sintered NdFeB magnets, it is easier to form. The horizontally placed irregularly shaped magnet slot can improve the power density of the motor. The two sides of the U-shaped magnet slot are trapezoidal from wide to narrow, and the middle of the U-shaped magnet slot is an arc structure of equal width. The ferrite magnets installed inside it save a lot of costs.

[0023] 2. The rotor core body has two magnetic barrier bodies on each side of the single pole, which can improve motor efficiency, reduce the harmonic content of the air gap magnetic field, thereby increasing the service life of the motor, saving costs, improving stability, and making the design flexible to meet the needs of different application scenarios. Attached Figure Description

[0024] Figure 1 This is a three-dimensional structural diagram of the rotor core body of the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the U-shaped magnetic steel channel and the horizontally placed irregularly shaped magnetic steel channel of the present invention;

[0026] Figure 3 This is a three-dimensional structural diagram of the horizontally placed irregularly shaped magnetic steel groove of the present invention;

[0027] Figure 4 This is a three-dimensional structural diagram of the U-shaped magnetic steel channel of the present invention;

[0028] Figure 5 This is a three-dimensional structural diagram of the teardrop-shaped weight-reducing hole of the present invention;

[0029] Figure 6 This is a partially enlarged structural schematic diagram of the rotor core body of the present invention;

[0030] Figure 7 This is a schematic diagram of the effect curve of the h2 / h1 ratio on the back EMF of the unloaded line in this invention;

[0031] Figure 8 This is a schematic diagram of the effect curve of the L1 / L2 ratio on the back EMF of the unloaded line in this invention;

[0032] Figure 9 This is a schematic diagram showing the effect of the h4 / h3 ratio on efficiency in this invention.

[0033] In the figure: 1. Rotor core body; 2. U-shaped magnet slot; 3. Horizontal irregular magnet slot; 4. Ferrite magnet; 5. Molded neodymium iron boron magnet; 6. Teardrop-shaped weight reduction hole; 7. Magnetic barrier body. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figures 1-9 The present invention provides the following technical solution:

[0036] Example 1: To address the problems existing in the use of current motor rotor laminations and magnet structures, this example discloses the following technical solution: a motor rotor lamination and magnet structure, comprising a rotor core body 1, wherein U-shaped magnet slots 2 are formed at equal angles inside the rotor core body 1. The U-shaped magnet slots 2 formed at equal angles have a trapezoidal structure that narrows from wide to narrow on both sides, and the middle part of the U-shaped magnet slots 2 has an arc-shaped structure of equal width; wherein, the U-shaped magnet slots 2 formed at equal angles are used to install ferrite magnets 4.

[0037] like Figure 1 , Figure 4 As shown, the rotor core body 1 has U-shaped magnet slots 2 opened at equal angles inside. The U-shaped magnet slots 2 are set with trapezoidal structures that narrow from wide to narrow on both sides and an arc structure with equal width in the middle, which saves a lot of costs. At the same time, magnetic isolation bridges are opened on both sides of the U-shaped magnet slots 2 to avoid magnetic leakage, improve the utilization rate of the internal space of the rotor core body 1, improve the filling effect, and ensure the strength of the ferrite magnets 4.

[0038] The rotor core body 1 has horizontally shaped magnetic steel slots 3 opened at equal angles inside, and the horizontally shaped magnetic steel slots 3 are located at the center position of the U-shaped magnetic steel slots 2 near the outer side of the rotor core body 1; wherein, the horizontally shaped magnetic steel slots 3 opened at equal angles are used to install molded neodymium iron boron magnets 5.

[0039] like Figures 2-3 As shown, the horizontal irregular magnetic steel groove 3 and the U-shaped magnetic steel groove 2 are opened one-to-one. By installing molded neodymium iron boron magnets 5 inside the horizontal irregular magnetic steel groove 3, the circular structure at the four corners is used to prevent magnetic leakage. Compared with sintered neodymium iron boron, it is easier to form and improves the power density of the motor.

[0040] The two side platforms of the horizontally placed irregularly shaped magnetic steel groove 3 have a width of h1 and a length of L1. The width of the narrowest part in the middle of the horizontally placed irregularly shaped magnetic steel groove 3 is h2, and the vertical length of the arc of the horizontally placed irregularly shaped magnetic steel groove 3 is L2, and h2 is satisfied.

[0041] The width of the wide side of the U-shaped magnetic groove 2 is h3, and the vertical length of the U-shaped magnetic groove 2 is L3. The width of the narrow side of the U-shaped magnetic groove 2 is h4, and the vertical length of the arc of the U-shaped magnetic groove 2 is L4, which simultaneously satisfies h4. <h3,L4<L3,0.4<h4 / h3<0.6,0.7<L3 / L4<0.9。

[0042] The outer diameter of the rotor core body (1) is D2, and the inner diameter of the rotor core body (1) is D3, and D2 is satisfied. COS(α / 2)<D3<D2 ​COSα, α=360 / P, P is the number of poles of the motor, P=4, 6, 8.

[0043] The diameter of the upper middle arc of the U-shaped magnetic steel groove 2 is D4, and it also satisfies D2. sin(α / 3) <D4<D2 sin(α / 2).

[0044] The diameter of the lower middle arc of the U-shaped magnetic groove 2 is D5, and it also satisfies D2. [sin(π / 3) α] <D5<D2 [sin(2π / 3) α].

[0045] The central angle of the upper middle circle of the U-shaped magnetic steel trough 2 is n1, and the central angle of the lower middle circle of the U-shaped magnetic steel trough 2 is n2, which satisfies (n1 / 360°). π D4 < (n2 / 360°) π D5.

[0046] The rotor core body 1 has teardrop-shaped weight reduction holes 6 opened at equal angles inside, and the teardrop-shaped weight reduction holes 6 are located between the U-shaped magnet slot 2 and the horizontal irregular magnet slot 3.

[0047] The large circle diameter of the teardrop-shaped weight-reducing hole 6 is r1, and the small circle diameter of the teardrop-shaped weight-reducing hole 6 is r2, satisfying 3. r2<2 r1.

[0048] Inside the rotor core body 1, magnetic barrier bodies 7 are respectively arranged on both sides of a single stage. The magnetic barrier bodies 7 are distributed symmetrically in pairs about the transversely placed irregularly shaped magnetic steel slots 3. The width of the magnetic barrier body 7 near the transversely placed irregularly shaped magnetic steel slot 3 is h5 and the length is L5, while the width of the magnetic barrier body 7 near the U-shaped magnetic steel slot 2 is h6 and the length is L6, satisfying 0.9. <h5 / h6<1.1,0.9<L5 / L6<1.1。

[0049] Satisfies (n1 / 360°) π D4<2 [(h5 L5)+(h6) L6)]<(n2 / 360°) π D5.

[0050] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A rotor lamination and magnet structure for an electric motor, comprising a rotor core body (1), wherein a U-shaped magnet groove (2) is provided at equal angles inside the rotor core body (1), and a transverse irregular magnet groove (3) is provided at equal angles inside the rotor core body (1), wherein the transverse irregular magnet groove (3) is located at the center position of the U-shaped magnet groove (2) near the outer side of the rotor core body (1); Its features are, Also includes: The U-shaped magnetic steel groove (2) with equal angles has a trapezoidal structure that narrows from wide to narrow on both sides, and the middle part of the U-shaped magnetic steel groove (2) has an arc-shaped structure with equal width. Among them, the U-shaped magnet groove (2) with equal angles is used to install ferrite magnet (4). Among them, the horizontal irregular magnetic steel groove (3) opened at equal angles is used to install molded neodymium iron boron magnets (5). The width of the wide side of the U-shaped magnetic groove (2) is h3, and the vertical length of the U-shaped magnetic groove (2) is L3. The width of the narrow side of the U-shaped magnetic groove (2) is h4, and the arc vertical length of the U-shaped magnetic groove (2) is L4, which simultaneously satisfies h4. <h3,L4<L3,0.4<h4 / h3<0.6,0.7<L3 / L4<0.9; The diameter of the upper middle arc of the U-shaped magnetic groove (2) is D4, and it also satisfies D2. sin(α / 3) <D4<D2 sin(α / 2); The angle of the central angle of the upper middle circle of the U-shaped magnetic groove (2) is n1, and the angle of the central angle of the lower middle circle of the U-shaped magnetic groove (2) is n2, which satisfies (n1 / 360°). π D4 < (n2 / 360°) π D5.

2. The rotor lamination and magnet structure for an electric motor according to claim 1, characterized in that: The width of the two side platforms of the horizontally placed irregularly shaped magnetic steel groove (3) is h1 and the length is L1. The width of the narrowest part of the horizontally placed irregularly shaped magnetic steel groove (3) is h2, and the vertical length of the arc of the horizontally placed irregularly shaped magnetic steel groove (3) is L2, and it satisfies h2 <h1,L1<L2,0.5<h2 / h1<0.8,0.15<L1 / L2<0.35。 3. The rotor lamination and magnet structure for an electric motor according to claim 1, characterized in that: The outer diameter of the rotor core body (1) is D2, and the inner diameter of the rotor core body (1) is D3, and D2 is satisfied. COS(α / 2)<D3<D2 COSα, α=360 / P, P is the number of poles of the motor, P=4, 6, 8.

4. The rotor lamination and magnet structure for an electric motor according to claim 1, characterized in that: The diameter of the lower middle arc of the U-shaped magnetic groove (2) is D5, and it also satisfies D2. [sin(π / 3) α] <D5<D2 [sin(2π / 3) α].

5. The rotor lamination and magnet structure for an electric motor according to claim 1, characterized in that: The rotor core body (1) has teardrop-shaped weight reduction holes (6) at equal angles inside, and the teardrop-shaped weight reduction holes (6) are located between the U-shaped magnet slot (2) and the horizontal irregular magnet slot (3). The large circle diameter of the teardrop-shaped weight-reducing hole (6) is r1, and the small circle diameter of the teardrop-shaped weight-reducing hole (6) is r2, satisfying 3. r2<2 r1.

6. The rotor lamination and magnet structure for an electric motor according to claim 1, characterized in that: The rotor core body (1) has magnetic barrier bodies (7) on both sides of a single stage, and the magnetic barrier bodies (7) are symmetrically distributed in pairs about the transverse irregular magnetic steel slots (3). The width of the magnetic barrier body (7) near the transverse irregular magnetic steel slot (3) is h5 and the length is L5, and the width of the magnetic barrier body (7) near the U-shaped magnetic steel slot (2) is h6 and the length is L6, satisfying 0.

9. <h5 / h6<1.1,0.9<L5 / L6<1.1。 7. The rotor lamination and magnet structure for an electric motor according to claim 1, characterized in that: Satisfies (n1 / 360°) π D4<2 [(h5 L5)+(h6) L6)] <(n2 / 360°) π D5.

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