Rotor punching sheet structure, rotor iron core and motor

Abstract

The invention provides a rotor punching sheet structure, a rotor iron core and a motor, the rotor punching sheet structure comprises a body, the body is provided with a plurality of magnetic poles, the plurality of magnetic poles are arranged at intervals along the circumferential direction of the body, each magnetic pole comprises a magnetic steel groove, and a connecting part is arranged between the magnetic steel grooves of two adjacent magnetic poles close to the periphery of the body. The magnetic steel grooves are formed in the periphery of the body, the connecting parts are located at the positions close to the periphery of the body, the minimum distance H1 exists between the magnetic steel grooves and the periphery of the body, the width of the connecting parts is H2 in the circumferential direction of the body, and the requirement that H1 * H2 = 0 is met. According to the invention, the magnetic leakage of the magnetic steel can be reduced, and the torque output capability of the rotor is improved.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a rotor lamination structure, a rotor core, and a motor. Background Technology

[0002] Existing permanent magnet synchronous motors mostly use permanent magnets for rotor excitation, and the rotor magnetic isolation design varies. The excitation method of the permanent magnet motor rotor is through permanent magnet excitation. The permanent magnet is generally rectangular in shape and embedded in the rotor magnet slots. Due to the high power density and cost reduction requirements of current permanent magnet motors, higher requirements are placed on the design of rotor structure dimensions and permanent magnet dimensions. It is necessary to reduce the leakage flux between rotor magnet poles, increase the motor output torque, improve torque density, and thus improve motor performance. At the same time, it is also necessary to reduce motor back EMF harmonics and improve the overall noise level of the motor. Therefore, higher requirements are placed on the magnetic bridge connection design between permanent magnet motor rotor poles and the magnetic isolation design between two adjacent poles. The motor design needs to minimize the leakage flux between rotor poles and improve the utilization rate of rotor magnets while ensuring the strength of the rotor structure.

[0003] Therefore, this invention studies and designs a rotor lamination structure and motor that can reduce magnetic leakage of the magnets and improve the rotor's output torque capability. Summary of the Invention

[0004] Therefore, the present invention provides a rotor lamination structure, a rotor core, and a motor, which can reduce magnetic leakage of the magnets and improve the rotor output torque capability.

[0005] To address the aforementioned problems, this invention provides a rotor lamination structure, comprising: a body having multiple magnetic poles arranged at intervals along the circumference of the body; each magnetic pole including a magnetic slot; a connecting portion being located between the magnetic slots of two adjacent magnetic poles near the outer periphery of the body; the connecting portion being located near the outer periphery of the body; a minimum distance H1 between the magnetic slot and the outer periphery of the body; and a width H2 along the circumference of the body, satisfying that H1*H2=0.

[0006] In some implementations, the value range of H1 is 0 ≤ H1 ≤ 0.5, and / or the value range of H2 is 0 ≤ H2 ≤ 0.5.

[0007] In some embodiments, grooves are provided on both side walls of the magnet groove along the circumference of the body, and the grooves penetrate the body along the axial direction of the body.

[0008] In some embodiments, the groove adopts a dovetail groove structure.

[0009] In some embodiments, the grooves on both sides of the magnet groove are staggered along the radial direction of the body.

[0010] In some embodiments, the magnet groove has a V-shaped structure or an I-shaped structure.

[0011] The present invention also provides a rotor core, including the aforementioned rotor lamination structure.

[0012] In some implementations...

[0013] When H1 = H2 = 0, the rotor lamination structure is the second lamination; when H1 ≠ 0 and H2 = 0, the rotor lamination structure is the first lamination.

[0014] In some embodiments, the rotor core is composed of alternating stacks of the second lamination and the first lamination.

[0015] The present invention also provides an electric motor comprising the aforementioned rotor core.

[0016] The rotor lamination structure, rotor core, and motor provided by this invention have the following beneficial effects:

[0017] With a minimum distance H1 between the magnetic steel groove and the outer periphery of the body, and the width of the connecting part being H2 along the circumference of the body, satisfying that H1*H2=0, an air groove is formed between the magnetic steel grooves of two adjacent magnetic poles or between the magnetic steel groove and the outer periphery of the body, thereby reducing magnetic leakage. At the same time, the rotor output torque is maximized, the motor output performance is highest, and the cogging torque value is reduced. Attached Figure Description

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the rotor lamination structure of the present invention. Figure 1 ;

[0020] Figure 2 This is a schematic diagram of the rotor lamination structure of the present invention. Figure 2 ;

[0021] Figure 3 This is a schematic diagram of the magnetic pole block of the second lamination in the rotor lamination structure of the present invention;

[0022] Figure 4 This is a schematic diagram of the structure of the body of the second lamination in the rotor lamination structure of the present invention;

[0023] Figure 5This is a schematic diagram of the structure of the first lamination in the rotor lamination structure of the present invention;

[0024] Figure 6 This is a schematic diagram of the rotor core in a motor according to another embodiment of the present invention;

[0025] Figure 7 This is a comparison diagram of the rotor lamination structure of the present invention and the back electromotive force of the prior art;

[0026] Figure 8 This is a diagram showing the difference in output torque between the rotor lamination structure of this invention and the prior art;

[0027] Figure 9 This is a comparison of the rotor lamination structure of the present invention with the cogging torque of the prior art. Figure 1 ;

[0028] Figure 10 This is a comparison of the rotor lamination structure of the present invention with the cogging torque of the prior art. Figure 2 .

[0029] The attached figures are labeled as follows:

[0030] 1. Body; 2. Magnet slot; 3. Connecting part; 4. Groove; 5. First punch; 6. Second punch. Detailed Implementation

[0031] 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. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0032] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0033] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0034] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0035] See also Figure 1-10 As shown, according to an embodiment of the present invention, a rotor lamination structure is provided, comprising: a body 1 having a plurality of magnetic poles arranged at intervals along the circumference of the body 1, each magnetic pole including a magnetic slot 2, and a connecting portion 3 between adjacent magnetic slots 2 near the outer periphery of the body 1, the connecting portion 3 being located near the outer periphery of the body 1, the magnetic slot 2 having a minimum distance H1 between it and the outer periphery of the body 1, and the width of the connecting portion 3 along the circumference of the body 1 being H2, which satisfies that H1*H2=0.

[0036] In this technical solution, the minimum distance H1 between the magnetic steel groove 2 and the outer periphery of the body 1 is achieved. Along the circumference of the body 1, the width of the connecting part 3 is H2, which satisfies that H1*H2=0. This allows an air groove to be formed between the magnetic steel grooves of two adjacent magnetic poles or between the magnetic steel groove and the outer periphery of the body, thereby reducing magnetic leakage. At the same time, the rotor output torque is maximized, the motor output performance is highest, and the cogging torque value is reduced.

[0037] With the minimum distance H1 between the magnet slot 2 and the outer periphery of the body 1, and the width H2 of the connecting part 3 along the circumference of the body 1, which satisfies H1*H2=0, the leakage flux can be reduced by reducing the size of the rotor inter-pole connecting rib, thereby solving the problem that the size of the rotor inter-pole connecting rib is weak and affects the strength of the motor under the original structure.

[0038] By adopting an independent rotor magnetic pole separation method from the rotor body, leakage flux between rotor poles is reduced and the back electromotive force of the motor is increased.

[0039] When an independent rotor pole separation method is adopted, the two rotor poles are completely disconnected, reducing the rotor output cogging torque and decreasing torque fluctuation during motor operation. The dimensions of the connecting bridge positions H1 and H2 between the rotor poles satisfy the following relationship. By adjusting the dimensions of H1 and H2, the rotor lamination shape can be changed. (See also...) Figure 3 and Figure 4 As shown, when H1 = H2 = 0, the rotor pole blocks are separated from the rotor body. At this time, the leakage flux of the rotor magnets decreases, resulting in the maximum rotor output torque and the highest motor output performance. When an air slot is formed between the magnet slots of two adjacent poles or between the magnet slot and the outer periphery of the motor body, the magnetic resistance of the air slot is high, and the magnetic lines of force cannot pass through, thus blocking the leakage flux. The magnetic lines of force will preferentially travel to the position with silicon steel connection. Compared with the existing technology, the connection with the silicon steel core magnetic bridge has low magnetic resistance, and some magnetic lines of force travel from this position.

[0040] In some implementations, the value range of H1 is 0 ≤ H1 ≤ 0.5, and / or the value range of H2 is 0 ≤ H2 ≤ 0.5.

[0041] In this technical solution, with the settings 0≤H1≤0.5 and 0≤H2≤0.5, when H1=0 and H2=0, the rotor core body and rotor magnetic poles can be set to be separate. The connection between the rotor magnetic poles, irregularly shaped magnets, and rotor body is achieved by assembling magnets, strengthening the connection structure. When H2=0, the leakage flux between the two poles of the motor rotor can be significantly reduced, improving the magnetic focusing ability between the two pole magnets. Compared to the scheme with H1=0 and H2≠0, the motor's back EMF output value is significantly improved. Specifically, when H2=0, the size of H1 is reduced. When H1=0, the rotor magnetic poles and rotor core body are completely isolated. By introducing this magnet structure to fix the rotor poles and the staggered connection between the two poles, the maximum back EMF output is achieved. (See also...) Figure 7 As shown, the rotor lamination structure of the present invention increases the back electromotive force compared with the prior art, from 24.96V to 26.94V.

[0042] In some implementations, by adjusting the size of the rotor inter-pole connecting rib from 0.5mm to 0mm for H1 and from 0.5mm to 0mm for H2, the no-load output back EMF can be increased and the back EMF harmonic distortion rate can be reduced, thereby increasing the output power density and thus improving the output torque capability.

[0043] With H1=0 and H2=0, the leakage flux decreases and the effective value of the back electromotive force increases, resulting in a decrease in the rate of change of back electromotive force harmonics. Specifically, the amplitudes of the 5th and 7th harmonics decrease, and the harmonic distortion rate of the back electromotive force decreases.

[0044] When the rotor poles are independently connected or the rotor is divided into independent sections, the effective value of the no-load back EMF and the total harmonic distortion rate of the back EMF change, as shown in the table below:

[0045]

[0046]

[0047]

[0048] In some implementations, when H1 = 0 and H2 = 0, the motor output capacity increases compared to the scheme where H1 = 0 and H2 ≠ 0, resulting in improved output torque and motor efficiency. The specific improvements are shown in the table below:

[0049]

[0050] In some implementations, see reference Figure 8 As shown, with the new design scheme, the output torque under the same current increases by 7% compared to the original scheme. After the magnetic bridge connecting the rotor body and the rotor poles is eliminated and the rotor poles are set separately, the output torque under the same current increases from the original 1.56NM to 1.68NM, and then to 1.69NM.

[0051] See also Figure 9 and Figure 10 As shown, compared with the existing technical solutions, the new design scheme 1 (H1=0, H2≠0) and the new design scheme 2 (H1=0, H2=0) further reduce the cogging torque.

[0052] In some embodiments, grooves 4 are provided on both sides of the magnet groove 2 along the circumference of the body 1, and the grooves 4 penetrate the body 1 along the axial direction of the body 1.

[0053] In this technical solution, by providing grooves 4 on both sides of the magnetic steel groove 2, it is possible to achieve the separation between the motor rotor magnetic pole block and the rotor body, and then to connect and fix the rotor magnetic pole block and the rotor core body through irregularly shaped magnets.

[0054] In some embodiments, the groove 4 adopts a dovetail groove structure.

[0055] In this technical solution, the groove 4 adopts a dovetail groove structure. The dovetail grooves on both sides need to be set on both sides of the magnet to limit and fix the segmented rotor core and the rotor body. The design of the dovetail groove position needs to be ensured to be on both sides of the magnet, and the specific position is not required.

[0056] In some embodiments, the grooves 4 on both sides of the magnet groove 2 are staggered along the radial direction of the body 1.

[0057] In this technical solution, the magnets and the rotor core are nested together. This nested structure design can strengthen the rotor structure under high-speed rotation. Compared with the original solution, it can reduce the rotor cogging torque, increase the rotor output torque capacity, and improve the motor efficiency.

[0058] In some implementations, the magnets are designed with dovetail convex structures on both sides along their length. The convex structures are staggered to form an asymmetrical structure. The convex shape of the magnets and the concave shape of the magnet slots work together to fix the rotor pole blocks and magnets, as well as the rotor body blocks, thereby ensuring the structural strength of the rotor during rotation.

[0059] In some embodiments, the magnetic groove 2 has a V-shaped structure or an I-shaped structure.

[0060] The rotor lamination structure of the present invention can solve the following problems: In the overall shape design of the rotor magnetic bridge and magnet slot of permanent magnet synchronous motor, it is necessary to design the magnet size according to the rotor magnet slot. The conventional magnet slot is rectangular, and the corresponding magnet size is square, which limits the design selection of different magnet shapes.

[0061] 2. Under the high-speed operating conditions of the motor rotor, magnetic isolation bridges are required between adjacent magnetic poles of the rotor to ensure the structural strength of the rotor under high-speed operation. Usually, the width of the connection is relatively wide, and the connection is wider at higher speeds. This design of the connecting bridge will increase the magnetic leakage between the magnetic poles of the magnet.

[0062] 3. The design of the rotor inter-pole connection bridge will affect the q-axis magnetic reluctance of the motor, which in turn will affect the q-axis inductance value, resulting in a decrease in rotor magnetic reluctance torque;

[0063] 4. By studying the connection form between the rotor segmented magnetic poles and the rotor body, and the characteristics of the design of the width of the connecting bridge between adjacent magnetic pole blocks, the study of the width dimension change at the magnetic isolation connection can further improve the output of higher back EMF while meeting structural strength requirements, reduce back EMF harmonics, thereby reducing motor core losses and improving the overall performance of the motor.

[0064] 5. The large number of separate magnetic pole blocks leads to low production efficiency in core stamping and rotor assembly.

[0065] The present invention also provides a rotor core, including the aforementioned rotor lamination structure.

[0066] In some embodiments, when H1 = H2 = 0, the rotor lamination structure is a second lamination 6, and when H1 ≠ 0 and H2 = 0, the rotor lamination structure is a first lamination 5.

[0067] The rotor core of this invention, through a thin connecting bridge design between the rotor pole blocks and the rotor body block, can reduce magnet leakage while ensuring rotor strength, thereby improving rotor output torque capability. The isolation design between the rotor pole blocks and the rotor body block eliminates the connecting bridge between adjacent rotor poles, further reducing magnet leakage and improving back electromotive force and rotor output torque capability. It also allows for the cross-lamination of two types of laminations to ultimately form the rotor core, satisfying both improved rotor output performance and rotor strength. In built-in permanent magnet synchronous motors, the permanent magnets are located inside the rotor core, resulting in poor heat dissipation. Significant eddy current losses and excessive temperature rise will inevitably have a serious impact on the performance of the permanent magnets and the efficiency of the motor. Eliminating the connecting bridge between adjacent rotor poles improves rotor heat dissipation, reduces rotor magnet temperature, minimizes the degradation of magnet properties caused by high temperatures during high-speed rotor operation, reduces rotor eddy current losses, reduces high-temperature demagnetization of rotor magnets, and improves the stability of magnet properties.

[0068] In the rotor core of this invention, a permanent magnet structure serves as the excitation excitation. The permanent magnet material can be ferrite, bonded NdFeB, sintered NdFeB, etc. The magnet assembly method can be clearance assembly, interference fit assembly, or one-time injection molding fixation of the magnet and rotor core. The shape of the magnet and the shape of the magnet slot can be semi-circular, rectangular, elliptical, etc.

[0069] In some embodiments, the rotor core is composed of the second lamination 6 and the first lamination 5 stacked alternately.

[0070] This technical solution employs two alternating rotor lamination installation methods, which balances motor performance and rotor strength, as well as mass production feasibility. It has minimal impact on motor performance and primarily facilitates mass production. The rotor laminations utilize a cross-laminated structure design, with the second lamination 6 and the first lamination 5 cross-laminated and interleaved to form the stator core. This design provides structural strength, improves motor rotor output performance, and avoids the need for numerous individual rotor pole pieces, significantly improving core stamping efficiency, reducing rotor assembly efficiency, and enabling large-scale mass production.

[0071] The present invention also provides an electric motor, including the aforementioned rotor core.

[0072] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0073] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A rotor lamination structure, characterized in that: include: The body (1) has multiple magnetic poles, which are arranged at intervals along the circumference of the body (1). Each magnetic pole includes a magnetic groove (2). There is a connecting part (3) between the magnetic grooves (2) of two adjacent magnetic poles near the outer periphery of the body (1). The connecting part (3) is located near the outer periphery of the body (1). There is a minimum distance H1 between the magnetic groove (2) and the outer periphery of the body (1). The width of the connecting part (3) along the circumference of the body (1) is H2, which satisfies that H1*H2=0.

2. The rotor lamination structure according to claim 1, characterized in that: The value range of H1 is 0 ≤ H1 ≤ 0.5, and / or the value range of H2 is 0 ≤ H2 ≤ 0.

5.

3. The rotor lamination structure according to claim 1, characterized in that: Along the circumference of the body (1), both sides of the magnetic steel groove (2) are provided with grooves (4), and the grooves (4) penetrate the body (1) along the axial direction of the body (1).

4. The rotor lamination structure according to claim 3, characterized in that: The groove (4) adopts a dovetail groove structure.

5. The rotor lamination structure according to claim 3, characterized in that: Along the radial direction of the main body (1), the grooves (4) on both sides of the magnetic steel groove (2) are staggered.

6. The rotor lamination structure according to claim 3, characterized in that: The magnetic steel groove (2) has a V-shaped structure or an "I"-shaped structure.

7. A rotor core, characterized in that, The rotor lamination structure includes any one of claims 1 to 6.

8. The rotor core according to claim 7, characterized in that: When H1 = H2 = 0, the rotor lamination structure is the second lamination (6); when H1 ≠ 0 and H2 = 0, the rotor lamination structure is the first lamination (5).

9. The rotor core according to claim 8, characterized in that: The rotor core is composed of the second lamination (6) and the first lamination (5) stacked alternately.

10. An electric motor, characterized in that, Includes the rotor core as described in claims 7 to 9.

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