A rotor lamination structure, a rotor, and an electric machine

Abstract

The application provides a rotor lamination structure, a rotor and a motor, and belongs to an energy-saving starting motor and an energy-saving motor, wherein the rotor lamination structure comprises a main body, a plurality of filling grooves are arranged on the outer peripheral wall of the main body, along the radial direction of the main body, a rotor center line is arranged on a magnetic pole forming area, along the circumferential direction of the main body, an outer side filling groove close to an adjacent magnetic pole forming area is arranged in one magnetic pole forming area, the rest of the one magnetic pole forming area is an inner side filling groove, and the size of the outer side filling groove is greater than that of the inner side filling groove in the one magnetic pole forming area; the slot opening of the filling groove has a center line, the slot body of the inner side filling groove is offset to the outer side of the magnetic pole relative to the center line of the slot opening, and the offset distance decreases successively along the direction of the rotor center line towards the adjacent magnetic pole forming area. According to the application, the technical problem that the sizes of the conductor grooves arranged on the rotor are the same and the conductor grooves are periodically distributed in the circumferential direction, resulting in high motor torque ripple in the prior art can be solved.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a rotor lamination structure, a rotor, and a motor, and is an energy-saving starter motor and an energy-saving electric motor. Background Technology

[0002] Existing self-starting permanent magnet synchronous motors combine the advantages of asynchronous motors (PMSMs) in terms of fixed-frequency self-starting with the asynchronous torque generated by the rotor squirrel cage bars. During synchronous operation, rotor squirrel cage losses are extremely low, resulting in higher efficiency compared to traditional three-phase asynchronous motors. However, self-starting PSMs require slots to be cut near the outer circumference of the rotor laminations to accommodate the squirrel cage bars. Due to the difference in materials (permeability) between the motor's squirrel cage bars and the rotor laminations, slotting the rotor laminations alters the rotor's magnetic circuit distribution, thereby changing the air gap magnetic flux density waveform. (See structural diagram). Figure 1 As shown, in the prior art, the rotor of a self-starting permanent magnet motor often adopts the rotor slot structure of an asynchronous induction motor. The conductor slots on the rotor are of the same size and are periodically distributed in the circumferential direction. Since the permeability of the conductive material (usually aluminum or copper) filling the conductor slots is much lower than that of the iron core material, the equivalent magnetic permeability of the rotor is uneven, which destroys the smooth symmetry of the magnetic circuit, modulates the air gap magnetic flux density waveform, generates high-order harmonic components, and thus aggravates the torque pulsation of the motor.

[0003] Because the conductor slots on the rotors in the prior art are of the same size and periodically distributed in the circumferential direction, there are technical problems such as uneven equivalent magnetic permeability and high torque pulsation. Therefore, this invention studies and designs a rotor lamination structure, rotor, and motor, which belong to the category of energy-saving starter motors and energy-saving electric motors. Summary of the Invention

[0004] Therefore, the present invention provides a rotor lamination structure, a rotor, and a motor, which belong to the category of energy-saving starter motors and energy-saving electric motors. It can solve the technical problem in the prior art where the conductor slots on the rotor are of the same size and periodically distributed in the circumferential direction, resulting in high motor torque pulsation.

[0005] To address the aforementioned problems, this invention provides a rotor lamination structure. The device includes: a main body, on the outer peripheral wall of which are provided a plurality of filling grooves for installing squirrel cage guide bars, the filling grooves penetrating the main body along the axial direction; the plurality of filling grooves are arranged at intervals along the circumference of the main body; the main body has two or more magnetic pole forming regions corresponding to rotor magnetic poles, each magnetic pole forming region is provided with a magnetic steel groove, and a permanent magnet is disposed in the magnetic steel groove; along the radial direction of the main body, the magnetic pole forming region has a rotor centerline, and the filling grooves on both sides of the rotor centerline within the magnetic pole forming region are symmetrically arranged; along the circumference of the main body, one magnetic pole forming region has an outer filling groove close to the adjacent magnetic pole forming region, and the rest of the magnetic pole forming region has inner filling grooves, and within one magnetic pole forming region, the size of the outer filling groove is larger than that of the inner filling groove; the groove opening of the filling groove has a centerline, and the groove body of the inner filling groove is offset outward relative to the centerline of its groove opening, and the offset distance decreases sequentially along the rotor centerline toward the adjacent magnetic pole forming region.

[0006] In some embodiments, within one of the magnetic pole forming regions, there are m filling grooves between the circumferential edge of the magnetic pole forming region and the rotor centerline, wherein the filling groove closest to the circumferential edge of the magnetic pole forming region relative to the rotor centerline is the first filling groove.

[0007] In some embodiments, within a magnetic pole region, the depth of the first filling groove is Hr1, the outer radius of the main body is R1, and the radius of the circle formed by the outer end of the magnet groove along the radial direction of the main body is R2, which satisfies 0.62(R1-R2) ≤ Hr1 ≤ 0.72 (R1-R2); and within a magnetic pole region, the main body corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in two first filling grooves has a first arc length, and the main body corresponding to the center of the inner sidewall near the rotor centerline in two first filling grooves has a second arc length, the ratio of the first arc length to the pole pitch is a1, the ratio of the second arc length to the pole pitch is a2, and the pole arc coefficient is ap, which satisfies ap ≤ a1 ≤ 1.1 ap, 0.80 ap ≤ a2 ≤ 0.85 ap.

[0008] In some embodiments, the inner wall of the first filling groove near the circumferential edge of the magnetic pole forming region has a distance x1 between it and the center of the groove opening, and the inner wall of the first filling groove near the rotor centerline has a distance x2 between it and the center of the groove opening, which satisfies x1 < x2.

[0009] In some embodiments, m is 4. Within one of the magnetic pole forming regions, between the rotor centerline and the circumferential edge of the magnetic pole forming region, along the direction from the rotor centerline toward the circumferential edge of the magnetic pole forming region, a fourth filling groove, a third filling groove, a second filling groove, and a first filling groove are sequentially arranged on the main body. The fourth filling groove, the third filling groove, and the second filling groove have the same groove depth Hr2 and groove width Br2. The groove width of the first filling groove is Br1, which satisfies 0.5 Br1 ≤ Br2 ≤ 0.6 Br1.

[0010] In some embodiments, within a magnetic pole forming region, the main body corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two fourth filling grooves has a fifth arc length, the main body corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two third filling grooves has a fourth arc length, and the main body corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two second filling grooves has a third arc length. The ratio of the fifth arc length to the pole distance is a5, the ratio of the fourth arc length to the pole distance is a4, and the ratio of the third arc length to the pole distance is a3. The a5, a3, and a4 satisfy the following relationships with the pole arc coefficient ap: 0.73 ap ≤ a3 ≤ 0.78 ap, 0.39 ap ≤ a4 ≤ 0.44 ap, and 0.17 ap ≤ a5 ≤ 0.22 ap.

[0011] In some embodiments, the inner wall of the second filling groove near the circumferential edge of the magnetic pole forming region has a distance x3 between it and the center of the groove opening; the inner wall of the third filling groove near the circumferential edge of the magnetic pole forming region has a distance x4 between it and the center of the groove opening; and the inner wall of the fourth filling groove near the circumferential edge of the magnetic pole forming region has a distance x5 between it and the center of the groove opening, which satisfies Br2 / 2 < x3 < x4 < x5 < Br2.

[0012] In some embodiments, the number of filling slots on the main body is S2, the number of stator slots of the motor stator is S1, and the number of poles of the motor is 2P, which satisfies the relationship S1-S2 = k × 2P, where k = ±1 or k = ±2.

[0013] In some embodiments, the ratio between the outer diameter of the body and the outer diameter of the motor stator is 0.6 to 0.7.

[0014] The present invention also provides a rotor comprising the aforementioned rotor lamination structure.

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

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

[0017] By adjusting the size of the outer slots, a high-resistivity "shielding zone" is constructed in the high-magnetic-magnetic-distortion area at the edge of the permanent magnet. This forces the magnetic lines of force to pass perpendicularly through the air gap, effectively suppressing the waveform flattening caused by edge leakage magnetic flux, thereby increasing the fundamental amplitude and weakening higher harmonics. The offset arrangement of the filling slots causes the local magnetic reluctance along the circumferential direction of the rotor surface to no longer exhibit a simple periodic square wave change, but is reconstructed into a nonlinear gradient permeability distribution. This distribution causes the magnetic lines of force to deflect and redistribute when passing through the squirrel-cage slot region, thereby exciting a reverse harmonic magnetomotive force in the air gap magnetic field that is opposite to the direction of the stator cogging harmonics or the permanent magnet edge distortion. This reverse component spatially superimposes and interferes with the original distorted magnetic field, producing a harmonic cancellation effect. This effectively improves the distortion of the air gap magnetic flux density waveform, making it closer to an ideal sine wave. Ultimately, it suppresses the pulsating torque caused by the interaction of harmonic magnetic fields from a physical source, improving the motor's running stability and reducing vibration noise, thus providing an energy-saving starter motor and an energy-saving electric motor. 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 partial structural diagram of a rotor lamination in the prior art;

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

[0021] Figure 3 yes Figure 2 Enlarged view of point A in the middle;

[0022] Figure 4 This is a partial structural schematic diagram of the rotor lamination structure of the present invention;

[0023] Figure 5 This is a comparison diagram of the rotor lamination structure of the present invention and the radial air gap magnetic flux density of the prior art;

[0024] Figure 6 This is a comparison diagram of the rotor lamination structure of the present invention and the electromagnetic torque of the prior art.

[0025] The attached figures are labeled as follows:

[0026] 1. Main body; 2. Magnet slot; 3. Permanent magnet; 4. Filling slot; 41. Slot opening; 42. First filling slot; 43. Second filling slot; 44. Third filling slot; 45. Fourth filling slot; 421. First point; 422. Second point; 5. Shaft hole. Detailed Implementation

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] See also Figure 1-6 As shown, according to an embodiment of the present invention, a rotor lamination structure is provided, characterized in that: it includes: a main body 1, on the outer peripheral wall of the main body 1, a plurality of filling grooves 4 are provided, the filling grooves 4 are used to install squirrel cage guide bars, and the filling grooves 4 penetrate the main body 1 along the axial direction of the main body 1; the plurality of filling grooves 4 are arranged at intervals along the circumference of the main body 1; the main body 1 has two or more magnetic pole forming regions corresponding to the rotor magnetic poles, each magnetic pole forming region is provided with a magnetic steel groove 2, and a permanent magnet 3 is provided in the magnetic steel groove 2; along the radial direction of the main body 1, the magnetic pole forming region has a rotor centerline, and the magnetic pole forming region is provided with a permanent magnet 3. The filling grooves 4 on both sides of the rotor centerline are symmetrically arranged; along the circumference of the main body 1, one magnetic pole forming region has an outer filling groove 4 close to the adjacent magnetic pole forming region, and the rest of the magnetic pole forming region are inner filling grooves 4, and the size of the outer filling groove 4 in one magnetic pole forming region is larger than that of the inner filling groove 4; the groove openings 41 of the filling grooves 4 are evenly distributed on the outer circle of the rotor and have a centerline, and the groove body of the inner filling groove 4 is offset outward from the magnetic pole relative to the centerline of its groove opening 41, and the offset distance decreases sequentially along the rotor centerline toward the adjacent magnetic pole forming region.

[0032] In this technical solution, since the filling grooves 4 on both sides of the rotor centerline are symmetrically arranged within the magnetic pole forming region, that is, along the circumference of the main body 1, between the rotor centerline and the end of the magnetic pole forming region, the filling grooves 4 on both sides of the rotor centerline, except for the outer filling grooves 4, have their groove bodies offset outward relative to the centerline of their groove openings 41, and the offset distance decreases sequentially along the rotor centerline toward the adjacent magnetic pole forming region. By adjusting the size of the outer slots, a high-resistivity "shielding zone" is constructed in the high-magnetic-magnetic-distortion area at the edge of the permanent magnet. This forces the magnetic lines of force to pass perpendicularly through the air gap, effectively suppressing the waveform flattening caused by edge leakage magnetic flux, thereby increasing the fundamental amplitude and weakening higher harmonics. The offset arrangement of the filling slots causes the local magnetic reluctance along the circumferential direction of the rotor surface to no longer exhibit a simple periodic square wave change, but is reconstructed into a nonlinear gradient permeability distribution. This distribution causes the magnetic lines of force to deflect and redistribute when passing through the squirrel-cage slot region, thereby exciting a reverse harmonic magnetomotive force in the air gap magnetic field that is opposite to the direction of the stator cogging harmonics or the permanent magnet edge distortion. This reverse component spatially superimposes and interferes with the original distorted magnetic field, producing a harmonic cancellation effect. This effectively improves the distortion of the air gap magnetic flux density waveform, making it closer to an ideal sine wave. Ultimately, it suppresses the pulsating torque caused by the interaction of harmonic magnetic fields from a physical source, improving the motor's running stability and reducing vibration noise, thus providing an energy-saving starter motor and an energy-saving electric motor.

[0033] In some implementations, see reference Figure 2 and Figure 3 As shown, the filling groove 4 is formed on the main body 1, and the filling groove 4 penetrates the main body 1 along the axial direction of the main body 1. The groove opening 41 of the filling groove 4 is located on the outer peripheral wall of the main body 1, and the main body 1 has a shaft hole 5 at its center.

[0034] In some implementations, see reference Figure 2 and Figure 3 As shown, there are multiple filling slots 4 within a magnetic pole, and the rotor centerline refers to a centerline extending radially from the centerline of the magnetic pole along the body 1.

[0035] In some implementations, see reference Figure 2 and Figure 3 As shown, within a magnetic pole region, along the circumference of the main body, the multiple filling grooves on the main body 1 are divided into the outermost filling groove 4 and the innermost filling groove 4. The filling groove 4 near the adjacent region refers to the outermost filling groove 4. There are two outermost filling grooves 4 in a magnetic pole region, which are arranged near the two ends of the circumference of a magnetic pole region, that is, near the adjacent magnetic pole region. The rest are innermost filling grooves 4.

[0036] In some embodiments, there is a gap between the permanent magnet 3 and the end of the magnetic steel groove 2, that is, along the extension direction of the permanent magnet 3, the extension direction of the permanent magnet 3 is the same as the extension direction of the magnetic steel groove 2, and an air groove is formed between the two ends of the permanent magnet 3 and the end of the magnetic steel groove 2 to prevent magnetic leakage. The filling groove 4 is located on the radial outside of the magnetic steel groove 2, and at least a portion of the filling groove 4 is arranged opposite to the magnetic steel groove 2.

[0037] In some embodiments, the filling slot 4 is used to install a conductive mouse cage; specifically, the filling slot 4 is used to install copper or aluminum strips. Part of the filling slot 4 is arranged adjacent to the magnetic barrier slot 2, with a gap between them.

[0038] In some embodiments, 1. The rotor lamination 1 is provided with multiple magnetic slots 2, multiple permanent magnets 3, multiple filling slots 4, and shaft holes 5. The multiple filling slots 4 are distributed on the outer periphery of the rotor, forming a magnetic barrier layer in the radial direction of the rotor; the slot openings 41 of the filling slots 4 are evenly distributed on the outer circle of the rotor lamination, and the slots are non-uniformly arranged within a single magnetic pole. The depth and width of the two filling slots 42 on the outer side of the magnetic pole are slightly larger than those of the inner filling slots. The slots of the inner filling slots are offset from the center line of the corresponding slot opening to the outer side of the magnetic pole, and the offset distance increases sequentially from the outside to the inside.

[0039] It should be noted that the fundamental magnetic field generated by the energized stator windings or the main magnetic field generated by the permanent magnet should ideally be a smooth, sinusoidal waveform in space. Due to the slotting in the rotor, the air gap reluctance or permeability changes periodically with the angle, which acts as a spatial "filter." When the magnetic field is aligned with the slot, the reluctance is high and the permeability is low, weakening the air gap magnetic flux density. The originally smooth sine wave becomes distorted after this periodic "strength-weakness transformation," producing higher harmonic components that were not originally present.

[0040] It's important to note that even with identically sized conductor slots periodically distributed circumferentially on the rotor, the non-uniformity of the rotor's equivalent magnetic permeability still occurs. This is due to the reluctance modulation effect, primarily caused by the low permeability of the filler material in the slots: Permeability differences: The conductor slots are filled with aluminum or copper, whose permeability is much lower than that of the core material. Periodic variations: Due to the periodic distribution of the slots circumferentially, the magnetic reluctance on the rotor surface fluctuates drastically with position, being high at the slots and low at the teeth. Equivalent result: This periodic variation in localized magnetic reluctance causes the overall equivalent magnetic permeability of the rotor to no longer be constant, but rather exhibits periodic pulsations. This non-uniformity disrupts the smooth symmetry of the magnetic circuit, exciting higher harmonics and leading to torque pulsation.

[0041] In some embodiments, within one of the magnetic pole forming regions, there are m filling grooves 4 between the circumferential edge of the magnetic pole forming region and the rotor centerline, and the filling groove 4 near the circumferential edge of the magnetic pole forming region relative to the rotor centerline is the first filling groove 42.

[0042] In this technical solution, see [reference] Figure 2 and Figure 3 As shown, within a magnetic pole region, along the circumference of the main body, the multiple filling grooves on the main body 1 are divided into the outermost filling groove 4 and the innermost filling groove 4. The filling groove 4 near the adjacent magnetic pole region refers to the first filling groove 42. There are two outermost first filling grooves 42 in a magnetic pole region. The first filling groove 42 is the filling groove near the circumferential edge of the magnetic pole forming region.

[0043] In some embodiments, within a magnetic pole region, the depth of the first filling groove 42 is Hr1, the outer radius of the main body 1 is R1, and the radius of the circle formed by the outer end of the magnet groove 2 along the radial direction of the main body 1 is R2, which satisfies 0.62 (R1-R2) ≤ Hr1 ≤ 0.72 (R1-R2); and within a magnetic pole region, the main body 1 corresponding to the center of the inner sidewall of the two first filling grooves 42 near the circumferential edge of the magnetic pole forming region has a first arc length, and the main body 1 corresponding to the center of the inner sidewall of the two first filling grooves 42 near the rotor centerline has a second arc length, the ratio of the first arc length to the pole pitch is a1, the ratio of the second arc length to the pole pitch is a2, and the pole arc coefficient is ap, which satisfies ap ≤ a1 ≤ 1.1 ap, 0.80 ap ≤ a2 ≤ 0.85 ap.

[0044] In this technical solution, by precisely controlling the depth and circumferential coverage of the outer squirrel cage slot through the aforementioned parameters, "magnetic circuit micro-shaping" is physically achieved. On the one hand, the appropriate slot depth ensures that the squirrel cage bars have sufficient induction path to generate strong asynchronous torque during the startup phase, while retaining sufficient iron yoke thickness to avoid magnetic saturation during synchronous operation. On the other hand, by utilizing the circumferential asymmetric layout constructed with ap ≤ a1 and a2 ≤ 0.85 ap, a specific reverse harmonic magnetic field is generated to counteract the fundamental distortion and higher harmonics caused by the edge effect of the permanent magnet and the stator slot teeth. Thus, while taking into account the efficient self-starting performance, the sinusoidal nature of the air gap magnetic flux density is significantly optimized, and electromagnetic torque pulsation and operating noise are greatly reduced.

[0045] It should be noted that the pole pitch of a motor refers to the distance between the center lines of two adjacent magnetic poles along the armature surface.

[0046] In some embodiments, along the radial direction of the main body 1, the groove 41 of the filling groove 4 has a first section and a second section. One end of the first section is connected to the inner sidewall of the filling groove 4, and the other end of the first section is connected to the second section. The end of the second section away from the first section is smoothly filtered with the outer peripheral wall of the main body 1. The width of the groove 41 at the second end is less than the groove width of the filling groove 4, that is, the first section is trumpet-shaped. The small opening of the trumpet shape is connected to the second section, and the large opening of the trumpet shape is connected to the sidewall of the filling groove 4. The width of the groove 41 of the first section is Hr0, and the depth of the groove 41 of the first section is Br0, which satisfies the relationship 0.5 Hr0 ≤ Br0 ≤ Hr0. This dimensional constraint ensures that the groove has good processability and synergistic effect with magnetic circuit performance, avoids magnetic field concentration and local saturation caused by Br0 being too small, or prevents it from being too large, which would lead to magnetic circuit discontinuity and reduced magnet utilization.

[0047] It should be noted that the width of the first slot 41 is in the circumferential direction of the main body 1, and the depth of the first slot 41 is in the radial direction of the main body 1.

[0048] In some embodiments, the inner wall of the first filling groove 42 near the circumferential edge of the magnetic pole forming region has a distance x1 between it and the center of the groove opening, and the inner wall of the first filling groove 42 near the rotor centerline has a distance x2 between it and the center of the groove opening, which satisfies x1 < x2.

[0049] In this technical solution, the filling groove 42 near the outer end of the magnet groove on a single magnetic pole has a groove body on the outer and inner sides of the magnetic pole. The distances x1 and x2 from the groove center line are in the groove, which satisfy the relationship x1 < x2. The asymmetrical groove edge layout can effectively control the magnetic flux distribution characteristics, guide the magnetic field to flow more uniformly in the radial direction, take into account the magnetic field enhancement and leakage magnetic field suppression of the magnet, and facilitate the smoothing of the air gap magnetic field.

[0050] The rotor lamination structure of this invention optimizes the rotor magnetic circuit distribution and significantly improves electromagnetic performance by employing filling slot structures of different sizes and setting different slot positions. On one hand, on a single magnetic pole, by increasing the depth and width of the outer filling slot, the local permeability distribution is effectively adjusted, the magnetic field path is optimized, and the air gap magnetic flux density waveform is adjusted, thereby reducing harmonic magnetic fields, mitigating torque pulsation, and improving motor vibration and noise issues. On the other hand, the inner filling slots within the same magnetic pole are symmetrically offset radially to both sides to form a non-uniform distribution structure, further guiding the magnetic flux direction, enhancing magnetic field smoothness, and improving air gap sinusoidality. In addition, the permanent magnet 3 is disposed in the V-shaped magnet slot, which fully utilizes the reluctance effect while generating permanent magnet magnetomotive force, realizing the superposition of permanent magnet torque and reluctance torque, significantly improving the overall torque density and power density of the motor.

[0051] In some embodiments, m is 4. Within one of the magnetic pole forming regions, between the rotor centerline and the circumferential edge of the magnetic pole forming region, along the rotor centerline toward the circumferential edge of the magnetic pole forming region, the main body 1 is sequentially arranged with a fourth filling groove 45, a third filling groove 44, a second filling groove 43, and a first filling groove 42. The fourth filling groove 45, the third filling groove 44, and the second filling groove 43 have the same groove depth Hr2 and groove width Br2. The groove width of the first filling groove 42 is Br1, which satisfies 0.5 Br1 ≤ Br2 ≤ 0.6 Br1.

[0052] In this technical solution, the entire magnetic pole region is 8. The relationship between the slot width Br1 of the outer slot 42 and the slot width Br2 of the inner slots 43, 44, and 45 under the first pole satisfies 0.5 Br1 ≤ Br2 ≤ 0.6 Br1. By limiting the gradient ratio between the outer and inner slot widths through the above parameters, the outer slot is set to be wider, 1.67 to 2 times larger than the inner slot. This forms a more significant "high magnetic reluctance shielding zone" at the edge of the permanent magnet, where magnetic field distortion is most severe, thereby effectively suppressing leakage flux and smoothing the peak of the air gap magnetic flux density. At the same time, the inner slots maintain a narrow width to avoid excessive weakening of the main magnetic flux path, which would lead to a decrease in the fundamental magnetomotive force and thus affect the motor's output torque performance. The air gap magnetic field distortion is more severe at the outer side, and a wider slot is used to more effectively weaken harmonics. The narrower inner slots ensure sufficient magnetic circuitry and avoid significantly affecting motor performance.

[0053] In some embodiments, within a magnetic pole forming region, the body 1 corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two fourth filling grooves 45 has a fifth arc length, the body 1 corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two third filling grooves 44 has a fourth arc length, and the body 1 corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two second filling grooves 43 has a third arc length. The ratio of the fifth arc length to the pole distance is a5, the ratio of the fourth arc length to the pole distance is a4, and the ratio of the third arc length to the pole distance is a3. The a5, a3, and a4 satisfy the following relationships with the pole arc coefficient ap: 0.73 ap ≤ a3 ≤ 0.78 ap, 0.39 ap ≤ a4 ≤ 0.44 ap, and 0.17 ap ≤ a5 ≤ 0.22 ap.

[0054] In this technical solution, a non-uniform gradient magnetic circuit modulation mechanism is constructed by defining the aforementioned parameters. The differentiated spatial arrangement of the three slots within the radial magnetic barrier layer alters the local permeability distribution function of the rotor surface, generating a high-order harmonic magnetic field opposite to the stator slot harmonics, thus achieving harmonic cancellation in the air gap. Simultaneously, this slot layout, gradually changing from the pole center to the edge, effectively guides a smooth transition of magnetic field lines, avoiding abrupt magnetic field changes and local saturation caused by slots of a single size. Ultimately, while ensuring the squirrel cage's starting performance, it enhances the sinusoidal nature of the air gap magnetic flux density, further suppressing electromagnetic torque pulsation.

[0055] In some embodiments, the inner wall of the second filling groove 43 near the circumferential edge of the magnetic pole forming region has a distance x3 between it and the center of its opening; the inner wall of the third filling groove 44 near the circumferential edge of the magnetic pole forming region has a distance x4 between it and the center of its opening; and the inner wall of the fourth filling groove 45 near the circumferential edge of the magnetic pole forming region has a distance x5 between it and the center of its opening, satisfying that Br2 / 2 < x3 < x4 < x5. <Br2。

[0056] In this technical solution, the filling groove located in the half region of a magnetic pole is offset outward from the magnetic pole relative to its center line, for example, the fourth filling groove 45, the third filling groove 44, and the second filling groove 43, as shown in the reference. Figure 3 As shown, x3 > x31, x4 > x41, and x5 > x51. This asymmetrical offset arrangement enhances the magnetic flux concentration effect in this region, which helps to balance the air gap magnetic field distribution. The distances x3, x4, and x5 from the outer edge of each slot to the corresponding slot centerline satisfy the relationship Br2 / 2 < x3 < x4 < x5 < Br2 with respect to the slot width Br2. That is, the above distances are between half the slot width Br2 / 2 and the overall slot width Br2 and increase sequentially. By effectively controlling the magnetic field path and saturation characteristics through gradient distribution, it helps to improve the local magnetic field uniformity, suppress harmonic magnetic flux density components, thereby improving the stability of motor torque output and reducing motor vibration noise.

[0057] In some embodiments, the slots 41 of the filling groove 4 are evenly distributed on the outer circle of the rotor lamination, and the relationship between the included angle θ between the center lines of two adjacent slots and the number of filling grooves S2 satisfies θ = 360 / S2.

[0058] In some embodiments, the filling groove 4 adopts a rectangular groove structure, with its two vertices near the bottom of the groove on the outer circle of the rotor lamination, as shown in the reference. Figure 3As shown, points 421 and 422, and similarly for the internal slots, are located on the same circumference with radius R3 centered on the geometric center of the rotor lamination. The relationship between this circumference radius R3 and the rotor outer radius R1 satisfies 0.97R1 ≤ R3 ≤ 0.985R1. The slots are connected to the slot openings via an angled structure. This limitation, achieved by controlling the slot bottom depth and coordinating with the angled design, ensures that the slot bottom depth accounts for only 1.5% to 3% of the rotor radius. This balances electromagnetic performance with mechanical structural reliability while ensuring the formation of an effective magnetic barrier to optimize the air gap magnetic field distribution and guarantee sufficient starting capability of the motor. It also maintains sufficient rotor outer edge yoke thickness to resist high-speed centrifugal force. The continuous annular slot layout in the rotor structure facilitates control of the magnetic flux path, improves magnetic flux uniformity, and avoids local magnetic pole distortion. The groove body is connected to the groove opening through a reasonably designed oblique structure, which ensures good demolding performance during mold processing, and at the same time realizes a smooth transition of the magnetic field in the groove opening area, reducing iron loss and noise caused by sudden changes in magnetic resistance.

[0059] In some embodiments, the magnet slots and filling slots within each pole are arranged in a mirror-symmetric manner with respect to the geometric center line of that pole, with consistent structural forms and symmetrical positions, ensuring a high degree of consistency in magnetic circuit characteristics and magnetic field distribution among the poles. Based on this, in the entire rotor lamination, the magnet and filling slot structures of adjacent poles form a periodic repeating arrangement, constituting a spatially symmetrical periodic distribution structure. The structure of each pole includes magnet slots 2 and filling slots 4, and these structures are arranged symmetrically about the geometric center line of the corresponding pole; the structures between each pole constitute a symmetrical periodic distribution.

[0060] In some embodiments, the magnetic slots are evenly arranged along the circumference of the rotor laminations, spaced at equal angles to form four symmetrical magnetic poles, achieving a bipolar symmetrical magnetic field excitation structure. Each magnetic pole is equipped with two interconnected magnetic slots, which are arranged in a V-shape with the pole's centerline as the axis of symmetry, thereby effectively guiding the magnetic lines of force to form a circular path and enhancing magnetic circuit efficiency. 8. The magnetic slots are evenly distributed along the circumference of the rotor laminations to form four magnetic poles; each magnetic pole is provided with two magnetic slots, and these two slots are interconnected and arranged in a V-shape.

[0061] In some embodiments, on the main body 1, the number of filling slots 4 is S2, the number of stator slots of the motor stator is S1, and the number of poles of the motor is 2P, which satisfies the relationship S1-S2 = k × 2P, where k = ±1 or k = ±2.

[0062] In this technical solution, by reasonably matching the stator and rotor slot poles, the structural harmonic characteristics of the motor are adjusted, and electromagnetic vibration and noise caused by the slot effect are suppressed.

[0063] The rotor lamination structure of this invention solves the problem in existing self-starting permanent magnet synchronous motors where the slotting of the squirrel cage guide bar filling grooves alters the motor's magnetic circuit distribution, but fails to fully utilize the different sizes and positions of the filling grooves to optimize the air gap magnetic flux density waveform, improve torque ripple, and thus enhance motor torque output stability and reduce vibration and noise. By incorporating self-starting guide bars in the rotor, the asynchronous torque generated during the starting phase achieves soft starting and smooth transition, combining excellent starting performance with high operating efficiency. Optimizing the filling groove structure improves the magnetic circuit distribution, making the air gap magnetic field waveform closer to an ideal sinusoidal distribution, effectively suppressing torque ripple and improving the smoothness and control stability of torque output. This design balances high efficiency, low ripple, and high reliability, making it suitable for high-performance motor systems requiring constant-frequency starting and stable output. By adopting a permanent magnet built-in structure, permanent magnet torque and reluctance torque are generated synchronously, effectively improving the overall torque output density of the motor and enhancing operating efficiency and dynamic performance. By designing a multi-specification, differentiated-size squirrel cage guide bar groove structure, fine control of the rotor magnetic circuit path is achieved, which helps to evenly distribute the air gap magnetic flux density, improve the sinusoidal nature of the magnetic flux density waveform, significantly reduce electromagnetic torque pulsation, improve the smoothness of torque output, and improve motor vibration and noise issues. At the same time, based on the optimized configuration of the rotor squirrel cage structure, the motor also has excellent self-starting capability. During the starting phase, the asynchronous electromagnetic torque drives the rotor to accelerate to the synchronous operating speed, effectively achieving constant frequency start-up.

[0064] In some embodiments, the ratio between the outer diameter of the main body 1 and the outer diameter of the motor stator is 0.6 to 0.7.

[0065] In this technical solution, while ensuring the compactness of the motor's radial structure, the motor also has a reasonable air gap between the stator and rotor.

[0066] The rotor lamination structure of the present invention takes a 4-pole rotor structure as an example. The rotor lamination 1 is provided with multiple magnetic steel slots 2, multiple permanent magnets 3, multiple filling slots 4 and shaft holes 5. The permanent magnets 3 are placed in the magnetic steel slots 2; the multiple filling slots 4 are distributed on the outer periphery of the rotor, and some filling slots are adjacent to the magnetic steel slots, forming a magnetic barrier layer in the radial direction of the rotor; the filling slots 4 are open slot structures. The slots 41 of the filling slots 4 are evenly distributed on the outer circle of the rotor lamination; the relationship between the slot depth Hr1 of the two outer filling slots 42 corresponding to one pole and the radius R1 of the outer circle of the rotor lamination and the radius R2 of the circle formed by the outer ends of the magnet slots 2 between different poles satisfies 0.62 (R1-R2) ≤ Hr1 ≤ 0.72 (R1-R2), and the ratios a1 and a2 of the arc length of the line connecting the midpoints of the outer and inner sides of the two outer filling slots 42 on the outer circle of the rotor to the pole pitch and the pole arc coefficient ap respectively satisfy ap ≤ a1 ≤ 1.1 ap and 0.80 ap ≤ a2 ≤ 0.85 ap. The internal filling grooves 43, 44, and 45 under the first pole have the same groove depth Hr2 and groove width Br2. The ratios a3, a4, and a5 of the arc length corresponding to the arc length of the line connecting the midpoints of the outer sides of the internal filling grooves 43, 44, and 45 on the outer circle of the rotor to the pole pitch, and the pole arc coefficient ap, satisfy the following relationships: 0.73 ap ≤ a3 ≤ 0.78 ap, 0.39 ap ≤ a4 ≤ 0.44 ap, and 0.17 ap ≤ a5 ≤ 0.22 ap, respectively. The relationship between the groove width Br1 of the outer groove 42 of the filling groove 4 under the first pole and the groove width Br2 of the inner grooves 43, 44, and 45 satisfies 0.5 Br1 ≤ Br2 ≤ 0.6 Br1. Thus, by adjusting the size of the outer slots, increasing the slot depth and width, a high-resistivity "shielding zone" is constructed in the high-magnetic-field distortion area at the edge of the permanent magnet. This forces the magnetic lines of force to pass perpendicularly through the air gap, effectively suppressing the waveform flattening caused by edge leakage magnetic flux, thereby increasing the fundamental amplitude and weakening higher harmonics. Furthermore, the offset arrangement of the filling slots prevents the local magnetic reluctance on the rotor surface from exhibiting a simple periodic square wave change. That is, the asymmetrical offset of the inner slots towards the outer poles reconstructs the local magnetic reluctance on the rotor surface into a reconstructed... A nonlinear gradient permeability distribution causes the magnetic field lines to deflect and redistribute when passing through the squirrel cage slot region. This generates a reverse harmonic magnetomotive force in the air gap magnetic field that is opposite to the direction of the stator slot harmonics or the distortion at the edge of the permanent magnet. This reverse component interferes with the original distorted magnetic field in space, producing a harmonic cancellation effect. This effectively improves the distortion of the air gap magnetic flux density waveform, making it closer to an ideal sine wave. Ultimately, it suppresses the pulsating torque caused by the interaction of harmonic magnetic fields from the physical source, improves the smoothness of motor operation, and reduces vibration noise.

[0067] The rotor lamination structure of the present invention effectively improves the sinusoidal nature of the magnetic flux density waveform in the air gap of the motor by optimizing the magnetic circuit topology layout, significantly reduces electromagnetic torque pulsation during operation, alleviates vibration and noise problems, and improves the uniformity of rotor magnetic field distribution and rotational stability.

[0068] The present invention also provides a rotor comprising the aforementioned rotor lamination structure.

[0069] The present invention also provides an electric motor comprising the aforementioned rotor.

[0070] The motor of this invention is a self-starting permanent magnet synchronous motor.

[0071] See results Figure 5 and Figure 6 As shown, compared with the air gap magnetic flux density and electromagnetic torque of the prior art, under the same stator and current, the motor of the present invention can improve the sinusoidal nature of the air gap magnetic flux density, has a comparable average output torque, and has lower torque ripple, which can effectively improve torque output stability and improve motor vibration and noise problems.

[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 main body (1) has multiple filling grooves (4) on its outer peripheral wall. The filling grooves (4) are used to install the rat cage guide bars. The filling grooves (4) penetrate the main body (1) along the axial direction of the main body (1). The multiple filling grooves (4) are arranged at intervals along the circumference of the main body (1). The main body (1) has two or more magnetic pole forming regions corresponding to the rotor magnetic poles. Each magnetic pole forming region is provided with a magnetic steel groove (2). A permanent magnet (3) is provided in the magnetic steel groove (2). Along the radial direction of the main body (1), the magnetic pole forming region has a rotor centerline. The filling grooves (4) on both sides of the rotor centerline in the magnetic pole forming region are symmetrically arranged. Along the circumference of the main body (1), one of the magnetic pole forming regions has an outer filling groove (4) close to the adjacent magnetic pole forming region, and the rest of the magnetic pole forming region is an inner filling groove (4). In addition, the size of the outer filling groove (4) in one magnetic pole forming region is larger than that of the inner filling groove (4). The groove opening (41) of the filling groove (4) has a center line. The groove body of the inner filling groove (4) is offset to the outside of the magnetic pole relative to the center line of its groove opening (41), and the offset distance decreases sequentially along the rotor centerline toward the adjacent magnetic pole forming region.

2. The rotor lamination structure according to claim 1, characterized in that: Within one of the magnetic pole forming regions, there are m filling grooves (4) between the circumferential edge of the magnetic pole forming region and the rotor centerline. The filling groove (4) near the circumferential edge of the magnetic pole forming region relative to the rotor centerline is the first filling groove (42).

3. The rotor lamination structure according to claim 2, characterized in that: Within a magnetic pole region, the depth of the first filling groove (42) is Hr1, the outer radius of the main body (1) is R1, and the radius of the circle formed by the outer end of the magnetic steel groove (2) along the radial direction of the main body (1) is R2, which satisfies 0.62 (R1-R2) ≤ Hr1 ≤ 0.72 (R1-R2); and within a magnetic pole region, the main body (1) corresponding to the center of the inner sidewall of the two first filling grooves (42) near the circumferential edge of the magnetic pole forming region has a first arc length, and the main body (1) corresponding to the center of the inner sidewall of the two first filling grooves (42) near the rotor centerline has a second arc length, the ratio of the first arc length to the pole pitch is a1, the ratio of the second arc length to the pole pitch is a2, and the pole arc coefficient is ap, which satisfies ap ≤ a1 ≤ 1.1 ap, 0.80 ap ≤ a2 ≤ 0.85 ap.

4. The rotor lamination structure according to claim 2, characterized in that: The inner wall of the first filling groove (42) near the circumferential edge of the magnetic pole forming region has a distance x1 between it and the center of the groove opening, and the inner wall of the first filling groove (42) near the rotor centerline has a distance x2 between it and the center of the groove opening, which satisfies that x1 < x2.

5. The rotor lamination structure according to claim 2, characterized in that: The m is 4. Within one of the magnetic pole forming regions, between the rotor centerline and the circumferential edge of the magnetic pole forming region, along the direction from the rotor centerline toward the circumferential edge of the magnetic pole forming region, the main body (1) is sequentially arranged with a fourth filling groove (45), a third filling groove (44), a second filling groove (43), and a first filling groove (42). The fourth filling groove (45), the third filling groove (44), and the second filling groove (43) have the same groove depth Hr2 and groove width Br2. The groove width of the first filling groove (42) is Br1, which satisfies 0.5 Br1 ≤ Br2 ≤ 0.6 Br1.

6. The rotor lamination structure according to claim 5, characterized in that: Within a magnetic pole forming region, the main body (1) corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two fourth filling grooves (45) has a fifth arc length, the main body (1) corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two third filling grooves (44) has a fourth arc length, and the main body (1) corresponding to the center of the inner sidewall near the circumferential edge of the magnetic pole forming region in the two second filling grooves (43) has a third arc length. The ratio of the fifth arc length to the pole distance is a5, the ratio of the fourth arc length to the pole distance is a4, and the ratio of the third arc length to the pole distance is a3. The a5, a3, and a4 satisfy the following conditions with the pole arc coefficient ap: 0.73 ap ≤ a3 ≤ 0.78 ap, 0.39 ap ≤ a4 ≤ 0.44 ap, and 0.17 ap ≤ a5 ≤ 0.22 ap.

7. The rotor lamination structure according to claim 5, characterized in that: The second filling groove (43) has a distance x3 between its inner wall near the circumferential edge of the magnetic pole forming region and the center of its groove opening; the third filling groove (44) has a distance x4 between its inner wall near the circumferential edge of the magnetic pole forming region and the center of its groove opening; and the fourth filling groove (45) has a distance x5 between its inner wall near the circumferential edge of the magnetic pole forming region and the center of its groove opening. These conditions satisfy Br2 / 2 < x3 < x4 < x5 < Br2.

8. A rotor lamination structure according to claim 1, characterized in that: On the main body (1), the number of filling slots (4) is S2, the number of stator slots of the motor stator is S1, and the number of poles of the motor is 2P, which satisfies the relationship S1-S2 = k× 2P, where k = ±1 or k = ± 2.

9. A rotor lamination structure according to claim 1, characterized in that: The ratio between the outer diameter of the main body (1) and the outer diameter of the motor stator is 0.6 to 0.

7.

10. A rotor, characterized in that: The rotor lamination structure includes any one of claims 1 to 9.

11. An electric motor, characterized in that: Includes the rotor lamination structure as described in claim 10.

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