Motor stator core

Abstract

The utility model relates to the technical field of motors, in particular to a motor stator core. The motor stator core comprises a plurality of punching sheets, a plurality of pear-shaped grooves extending along the radial direction are uniformly distributed on the inner circumference of each punching sheet, and two adjacent surfaces of each pear-shaped groove are in fillet transition, so that magnetic field concentration of sharp edges is eliminated, and the problem of overhigh local magnetic flux density is reduced; the arc-shaped structure of the pear-shaped groove can provide a smoother magnetic path, magnetic resistance is reduced, magnetic lines are distributed more reasonably, magnetic hysteresis loss is reduced, and a magnetic circuit is improved. All the punching sheets are stacked in the axial direction, the pear-shaped grooves in all the punching sheets are in one-to-one correspondence to form a plurality of inclined notches, and compared with original vertical notches of the stator iron core, the inclined notches of the stator iron core have the advantages that the space for accommodating windings is increased, and the magnetic field density is improved. And the inclined notches enable the stator teeth and the rotor teeth to be not completely aligned, so that the tooth harmonic phases are different and mutually offset, thereby weakening the overall harmonic, reducing the electromagnetic noise and vibration, and further improving the motor performance.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technical field especially relates to a motor stator core. BACKGROUND

[0002] With the increasing demand of new energy vehicles and high-end industrial equipment on the performance of driving motor, high power density, light weight and high efficiency become the core demand of motor design. At present, as the core component of motor magnetic circuit, the performance of motor core directly affects the energy conversion efficiency of motor.

[0003] In the prior art, the motor core is mostly made of silicon steel sheet by lamination, and the structure design often uses rectangular slot, trapezoidal slot or groove structure with sharp geometric features. Although such design can realize the basic magnetic circuit function, the sharp geometric shape (such as right angle or acute angle transition) of the groove edge is easy to cause excessive concentration of magnetic field in local area (such as slot opening or slot bottom sharp angle), forming "hot spot" with high magnetic flux density. This phenomenon not only aggravates the hysteresis loss and eddy current loss, but also increases the magnetic resistance due to the winding path of magnetic circuit, thereby reducing the magnetic energy transmission efficiency. SUMMARY

[0004] (I) Technical problem to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the utility model provides a motor stator core, which solves the technical problem of low magnetic energy transmission efficiency in the existing electronic core.

[0006] (II) Technical scheme

[0007] In order to achieve the above-mentioned purpose, the utility model adopts the main technical scheme including:

[0008] The utility model embodiment provides a motor stator core, which comprises a plurality of punching sheets; the punching sheet is of annular structure, and a plurality of radially extending pear-shaped grooves are uniformly distributed in the inner circumference of the punching sheet, and each adjacent two faces in the pear-shaped groove are connected through a round corner; all the punching sheets are stacked along the axial direction, and the pear-shaped grooves in all the punching sheets correspond to each other to form a plurality of inclined slot openings which are uniformly distributed in the inner circumference of the motor stator core.

[0009] Preferably, the slot opening width b of the pear-shaped groove is 1.3-1.9mm; the slot opening height h of the pear-shaped groove is 0.6-1mm; the inclined shoulder width b of the pear-shaped groove is 1.5-2.3mm; the inclined shoulder height h of the pear-shaped groove is 0.8-1.2mm; and the total groove depth h of the pear-shaped groove is 1.3-1.9mm. s0 s0 s1 s1 s ​​​​The pear-shaped slot has a shoulder width b of 0.5-1.5 mm, a shoulder width b of the pear-shaped slot is less than the shoulder width b of the pear-shaped slot s0 The shoulder width b of the pear-shaped slot is less than the shoulder width b of the pear-shaped slot s1 .

[0010] Preferably, one side of the punching piece is provided with a plurality of positioning protrusions, an inclined angle a is formed between the side wall of the positioning protrusion and the vertical direction, and the other side of the punching piece is provided with a positioning groove matched with the positioning protrusion one by one.

[0011] Preferably, the inclined angle a between the side wall of the positioning protrusion and the vertical direction is 8-15 degrees.

[0012] Preferably, a plurality of welding grooves are arranged on the outer circumference of the punching piece.

[0013] Preferably, the welding groove is arc-shaped, and a plurality of punching pieces are welded to form an integral body through the welding grooves.

[0014] Preferably, the punching piece is formed by punching and forming a Co-Fe amorphous alloy strip.

[0015] Preferably, the thickness of the Co-Fe amorphous alloy strip is 0.02-0.05 mm.

[0016] Preferably, the surface of the punching piece is coated with an insulating coating, and the thickness of the insulating coating is 0.01-0.05 mm.

[0017] (Three) beneficial effects

[0018] The beneficial effects of the utility model are:

[0019] The motor stator core of the utility model, including a plurality of punching pieces, since the punching piece is of annular structure, a plurality of pear-shaped slots extending along the radial direction are uniformly distributed on the inner circumference, the pear-shaped slots are all connected through a round corner between two adjacent surfaces, the magnetic field concentration of sharp edges is eliminated, thereby reducing the problem of excessively high local magnetic flux density, making the magnetic field distribution more uniform and the arc-shaped structure of the pear-shaped slot being able to provide a smoother magnetic path, reducing the magnetic resistance, making the magnetic line distribution more reasonable, reducing the magnetic hysteresis loss and improving the magnetic circuit. Since all the punching pieces are stacked along the axial direction, the pear-shaped slots in all the punching pieces correspond to form a plurality of inclined slots, compared with the original vertical slots of the stator core, the inclined slots of the stator core increase the space for accommodating the winding and improve the magnetic field density. And the inclined slots make the stator and rotor teeth not completely aligned, make the tooth harmonic phase different, offset each other, thereby weakening the overall harmonic, reducing the electromagnetic noise and vibration, and further improving the motor performance. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1A first perspective view of the punched sheet of the utility model;

[0021] Figure 2 A second perspective view of the punched sheet of the utility model;

[0022] Figure 3 A front view of the punched sheet of the utility model;

[0023] Figure 4 A Figure 3 Enlarged view of the middle A part;

[0024] Figure 5 A front view of the positioning protrusion;

[0025] Figure 6 A structure diagram of the motor stator core.

[0026]

Explanation of reference signs

[0027] 1: punched sheet; 11: positioning protrusion; 12: positioning groove; 13: pear-shaped groove; 14: welding groove;

[0028] 2: inclined notch. DETAILED DESCRIPTION

[0029] In order to better explain the utility model, so as to facilitate understanding, the following will be combined with the specific embodiments, and the utility model will be described in detail.

[0030] As Figure 1 shown, the utility model embodiment provides a motor stator core, and the motor stator core includes a plurality of punched sheets 1 formed by punching Co-Fe amorphous alloy strip material. Figure 4 As shown, each of the two adjacent faces in the pear-shaped groove 13 is connected through a round corner, wherein the pear-shaped groove 13 includes an arc face, two inclined faces and two parallel faces, the two inclined faces are oppositely arranged and connected with two sides of the arc face respectively, and the two parallel faces are oppositely arranged and connected with the other sides of the two inclined faces respectively. Figure 6 As shown, each punched sheet 1 is stacked along the axial direction, and the pear-shaped groove in each punched sheet 1 corresponds to form a plurality of inclined notches 2 distributed uniformly on the inner circumference of the motor stator core.

[0031] Due to the punching sheet 1 is punched from the Co-Fe amorphous alloy strip, the high permeability and low hysteresis loss of the Co-Fe amorphous alloy directly reduces the core loss and improves the magnetic energy transmission efficiency. At the same time, due to the pear-shaped slot 13 and the round corner transition, the magnetic field concentration of the sharp edge is eliminated, thereby reducing the problem of too high local magnetic flux density, making the magnetic field distribution more uniform, and the arc-shaped structure of the pear-shaped slot 13 can provide a smoother magnetic path, reduce the magnetic resistance, make the magnetic line distribution more reasonable, reduce the hysteresis loss, and improve the magnetic circuit. Due to the plurality of punching sheets 1 are stacked along the axial direction, the plurality of punching sheets form a plurality of inclined slots 2 one by one, and the inclined slots 2 of the stator core increase the space for accommodating the winding compared with the original vertical slots of the stator core, and improve the magnetic field density. And the inclined slots 2 make the stator and the rotor teeth not completely aligned, so that the tooth harmonics have different phases and offset each other, thereby weakening the overall harmonics, reducing electromagnetic noise and vibration, and further improving the motor performance.

[0032] In the actual application process, the inclination angle of the inclined slot 2 is 5-15°, and the stator core used in the embodiment has 48 teeth, and the inclination angle of the inclined slot 2 is selected to be 15°.

[0033] As shown in Figure 5 In order to ensure the installation precision of the plurality of punching sheets 1 and avoid the increase of magnetic resistance caused by the misplacement of the magnetic circuit, a plurality of positioning protrusions 11 are arranged on one side of the punching sheet 1, and an inclination angle α is formed between the side wall of the positioning protrusion 11 and the vertical direction, and a positioning groove 12 matched with the positioning protrusion 11 is arranged on the other side of the punching sheet 1, and the positioning protrusion 11 of one punching sheet 1 is inserted into the positioning groove 12 of the other punching sheet 1 between the adjacent two punching sheets 1. It should be noted that due to the inclined slots in the stator core, the positions of the positioning protrusions 11 and the positioning grooves 12 in each punching sheet 1 are slightly different, and the depth of the positioning groove 12 and the height of the positioning protrusion 11 are the same and do not exceed half of the thickness of the punching sheet 1.

[0034] In the embodiment, the inclination angle α between the side wall of the positioning protrusion 11 and the vertical direction is 8°-15°, which provides a self-locking function to prevent displacement of the punching sheet 1 during the stacking process and ensures the continuity of the magnetic circuit. At the same time, too small inclination angle will lead to difficulty in insertion, and too large inclination angle will reduce the positioning precision. This range takes into account the assembly efficiency and structural stability.

[0035] Preferably, the thickness of the Co-Fe amorphous alloy strip is 0.02-0.05mm, which balances the density and magnetic properties of the punching sheet 1, avoids that the punching sheet 1 is too thin and leads to insufficient strength of the punching sheet 1, and avoids that the punching sheet 1 is too thick and increases the eddy current loss.

[0036] The surface of the punching sheet 1 is coated with an insulating coating layer with a thickness of 0.01-0.05 mm to block the interlayer eddy current channel and reduce the additional loss under high-frequency working condition, and the insulation and magnetic circuit performance are optimized to avoid insulation failure caused by too thin insulating coating layer and the influence of too thick insulating coating layer on the lamination density.

[0037] As shown in Figure 4 , the slot opening width b s0 of the pear-shaped slot 13 is 1.3-1.9 mm, the slot opening height h s0 of the pear-shaped slot 13 is 0.6-1 mm, the inclined shoulder width b s1 of the pear-shaped slot 13 is 1.5-2.3 mm, the inclined shoulder height h s1 of the pear-shaped slot 13 is 0.8-1.2 mm, the total slot depth h s of the pear-shaped slot 13 is 14.2-15.5 mm, the half-slot angle β of the pear-shaped slot 13 is 160°-270°, and the slot bottom radius r of the pear-shaped slot 13 is 3.3-3.8 mm, wherein the slot opening width b s0 of the pear-shaped slot 13 is less than the inclined shoulder width b s1 of the pear-shaped slot 13.

[0038] By limiting the range of the pear-shaped slot 13, the magnetic flux distribution and the slot area utilization rate are balanced, the magnetic flux leakage and harmonic loss are reduced, the effective cross-sectional area of the magnetic circuit is expanded, the magnetic resistance is reduced, and the magnetic energy transmission efficiency is improved. In this embodiment, the slot opening width b s0 of the pear-shaped slot 13 is 1.6 mm, the slot opening height h s0 of the pear-shaped slot 13 is 0.8 mm, the inclined shoulder width b s1 of the pear-shaped slot 13 is 1.8 mm, the inclined shoulder height h s1 of the pear-shaped slot 13 is 1 mm, the total slot depth h s of the pear-shaped slot 13 is 14.9 mm, the half-slot angle β of the pear-shaped slot 13 is 170°, and the slot bottom radius r is 3.6 mm.

[0039] As shown in Figure 2 and Figure 6 , a plurality of welding grooves 14 are formed on the outer circumference of the punching sheet 1 to fix the punching sheet 1 by welding, enhance the mechanical strength of the whole core, reduce the magnetic circuit deformation caused by vibration, provide a positioning reference for subsequent welding, and avoid the interference of welding heat on the magnetic performance. The welding groove 14 is arc-shaped to reduce stress concentration, avoid cracking of the edge of the punching sheet 1 during welding, improve the axial stiffness of the core, and further reduce the magnetic resistance fluctuation caused by deformation of the magnetic circuit. A plurality of punching sheets 1 are welded to form an integral body by placing welding material in the welding grooves 14. The number of welding grooves 14 is 6-10 to ensure the welding strength while avoiding excessive welding points that cause local embrittlement of the material or discontinuity of the magnetic circuit.

[0040] In the description of the utility model, it is necessary to understand that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more than two, unless otherwise specifically limited.

[0041] In the utility model, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, it can be fixed connection, or detachable connection, or integrated; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium; it can be the communication inside two elements or the interaction relationship of two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0042] In the utility model, unless otherwise specifically defined and limited, the first feature is "on" or "under" the second feature, which can be direct contact of the first and second features, or indirect contact of the first and second features through intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature, can be directly above or obliquely above the first feature, or only indicate that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" the second feature, can be directly below or obliquely below the first feature, or only indicate that the horizontal height of the first feature is lower than that of the second feature.

[0043] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are contained in at least one embodiment or example of the utility model. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of different embodiments or examples without contradiction.

[0044] Although the embodiments of the utility model have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the utility model, and the ordinary skilled in the art can modify, modify, replace and change the above embodiments within the scope of the utility model.

Claims

1. An electric machine stator core, characterized in that, The punch piece (1) is annular in structure, and a plurality of radially extending pear-shaped grooves (13) are uniformly distributed on the inner circumference of the punch piece (1), and each two adjacent faces of the pear-shaped grooves (13) are connected by a rounded corner; All the punch pieces (1) are stacked in the axial direction, and the pear-shaped grooves (13) in all the punch pieces (1) one-to-one correspond to form a plurality of inclined slots (2) uniformly distributed on the inner circumference of the motor stator core; The half-slot angle β of the pear-shaped groove (13) is 160°-270°; The slot width b of the pear-shaped slot (13) s0 is 1.3-1.9 mm; The height h of the slot of the pear-shaped slot (13) s0 0.6-1 mm; The width b of the shoulder of the pear-shaped groove (13) s1 is 1.5-2.3 mm; The height h of the inclined shoulder of the pear-shaped groove (13) s1 is 0.8-1.2 mm; the total groove depth h of the pear-shaped groove (13) s is 14.2-15.5 mm; The slot bottom radius r of the pear-shaped groove (13) is 3.3-3.8 mm; 2. The motor stator core of claim 1, wherein: The slot width b of the pear-shaped slot (13) s0 The shoulder width b of the pear-shaped slot (13) s1 . One side of the punch piece (1) is provided with a plurality of positioning protrusions (11), and an inclined angle α is formed between the side wall of the positioning protrusion (11) and the vertical direction, and the other side of the punch piece (1) is provided with a positioning groove (12) matched with the positioning protrusion (11) one-to-one; Between the two adjacent punch pieces (1), the positioning protrusion (11) of one punch piece (1) is inserted into the positioning groove (12) of the other punch piece (1).

3. The motor stator core of claim 2, wherein: The inclined angle α between the side wall of the positioning protrusion (11) and the vertical direction is 8°-15°.

4. The motor stator core of claim 1, wherein: A plurality of welding grooves (14) are formed on the outer circumference of the punch piece (1).

5. The motor stator core of claim 4, wherein: The welding groove (14) is arc-shaped; A plurality of punch pieces (1) are welded to form an integral body through the welding grooves (14).

6. The motor stator core of claim 4, wherein: The punch piece is stamped and formed from a Co-Fe amorphous alloy strip.

7. The motor stator core of claim 6, wherein: The thickness of the Co-Fe amorphous alloy strip is 0.02-0.05 mm.

8. The motor stator core of claim 1, wherein: An insulating coating is coated on the surface of the punch piece (1), and the thickness of the insulating coating is 0.01-0.05 mm. ​

Images