A single-phase permanent magnet motor rotor

Abstract

The application relates to the field of single-phase permanent magnet motors and discloses a single-phase permanent magnet motor rotor which comprises rotor punching sheets, a plurality of groups of magnet groups are symmetrically arranged on the rotor punching sheets, the plurality of groups of magnet groups are distributed along the circumferential direction of the rotor punching sheets, each group of magnet groups comprises two strip-shaped permanent magnets, a first weight-reducing ventilation hole is arranged on the rotor punching sheet at the inner side end of each permanent magnet, a second weight-reducing ventilation hole is arranged on the rotor punching sheet between the two permanent magnets of each group, at least one magnetic gathering hole and at least one magnetic isolation hole are arranged on the rotor punching sheet between each two adjacent groups of magnet groups, and a magnetic short-circuit prevention magnetic hole is arranged on the rotor punching sheet at the outer side end of each permanent magnet. The rotor has the advantages of high strength, small single-side magnetic pulling force, high power density, low noise, low heat generation and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of single-phase permanent magnet motor, in particular to a single-phase permanent magnet motor rotor. BACKGROUND

[0002] The single-phase permanent magnet motor is a kind of synchronous motor using permanent magnet as rotor magnetic pole, and its stator winding is powered by single-phase ac power supply.Currently, the existing single-phase permanent magnet motor has a common problem of waveform difference due to the existence of third harmonic;At the same time, the magnetic field cannot rotate, so the pulse is serious during the load process, and the present situation is that the vibration and noise are large, and due to the existence of pulse magnetic field, the voltage regulation rate is abnormally large during the load process of motor.

[0003] Therefore, the existing single-phase permanent magnet motor at least has the defects of large volume, low power density, high voltage regulation rate, waveform difference and serious vibration and noise. SUMMARY

[0004] The present application relates to the field of single-phase permanent magnet motor, in particular to a single-phase permanent magnet motor rotor.

[0005] To achieve the above-mentioned purpose of the application, the technical scheme adopted by the present application is:

[0006] The present application provides a single-phase permanent magnet motor rotor, comprising: a rotor lamination, a plurality of groups of magnets are symmetrically arranged on the rotor lamination, the plurality of groups of magnets are distributed along the circumference of the rotor lamination, and each group of magnets comprises two permanent magnets in strip shape;

[0007] A first weight-reducing vent hole is arranged on the rotor lamination at the inner side end of each permanent magnet, a second weight-reducing vent hole is arranged on the rotor lamination between the two permanent magnets of each group, at least one magnetic concentration hole and at least one magnetic isolation hole are arranged on the rotor lamination between each adjacent two groups of magnets, and a magnetic short-circuit prevention magnetic hole is arranged on the rotor lamination at the outer side end of each permanent magnet.

[0008] Preferably, it further comprises: a central rotating shaft, the central rotating shaft is inserted into the rotor lamination, both ends of the rotor lamination are provided with end plates, the end plates are fixed on the end faces of the rotor lamination by a plurality of damping pull rods, and the end plates are provided with through holes corresponding to the first weight-reducing vent holes and the second weight-reducing vent holes.

[0009] Preferably, the first weight-reducing vent hole and the magnetic short-circuit prevention magnetic hole are both triangular holes, the second weight-reducing vent hole is a circular hole, and the magnetic isolation hole is a circular hole and / or a square hole.

[0010] Preferably, the two first weight-reducing vent holes at the inner side ends of the two adjacent permanent magnets of the non-identical group have a magnetic isolation hole therebetween, the magnetic isolation hole is a square hole, and the distance Q between the two first weight-reducing vent holes at the inner side ends of the two adjacent permanent magnets of the non-identical group ranges from 0.8 mm to 3.5 mm.

[0011] Preferably, the included angle between every two adjacent groups of magnet groups ranges from 90° to 116.2°.

[0012] Preferably, two magnetic aggregation holes are arranged on the rotor lamination between every two adjacent groups of magnet groups, and the cross section of each magnetic aggregation hole is in an elongated structure, and each magnetic aggregation hole is perpendicular to the side wall of the permanent magnet adjacent to the magnetic aggregation hole.

[0013] Preferably, the vertical distance from each magnetic aggregation hole to the inner side end edge of the permanent magnet adjacent to the magnetic aggregation hole is:

[0014] H = L * m;

[0015] In the formula, H is the vertical distance from each magnetic aggregation hole to the inner side end edge of the permanent magnet adjacent to the magnetic aggregation hole, L is the length of the cross section of each permanent magnet, and m is a first coefficient, and the value range of the first coefficient m is (0.3, 0.7).

[0016] Preferably, the minimum distance between the two magnetic aggregation holes between the two permanent magnets of the same group is determined according to the distance between the two permanent magnets of the group.

[0017] In the formula, G is the distance between the two permanent magnets of each group, k is a third coefficient, the value range of the third coefficient k is (0.05, 0.21), π is a circular constant, and D is the outer diameter of the rotor lamination.

[0018] G = k * π * D;

[0019] In the formula, G is the distance between the two permanent magnets of each group, k is a third coefficient, the value range of the third coefficient k is (0.05, 0.21), π is a circular constant, and D is the outer diameter of the rotor lamination.

[0020] Therefore, the minimum distance between the two magnetic aggregation holes between the two permanent magnets of the same group is:

[0021] E = b * G;

[0022] In the formula, E is the minimum distance between the two magnetic aggregation holes between the two permanent magnets of the same group, and b is a second coefficient, and the value range of the second coefficient b is (0.45, 0.7).

[0023] Preferably, a cutout extending in the axial direction of the rotor lamination is arranged on the outer wall of the rotor lamination outside each group of magnets.

[0024] Preferably, the depth of the cutout is less than 10 mm.

[0025] The beneficial effects of the present application are focused on:

[0026] 1. The first and second weight-reducing ventilation holes are arranged on the rotor lamination, which can reduce the weight of the rotor lamination, and form ventilation cavities in the rotation process of the rotor lamination, so as to quickly take away the heat inside the iron core; and a plurality of groups of magnets are symmetrically arranged on the rotor lamination, so that the rotor has high symmetry, high strength, small single-side magnetic pull, high power density, low noise, low heating and other advantages;

[0027] 2. The magnet gathering hole is arranged on the rotor lamination of the present application, which can gather the magnetic field generated by the permanent magnet, promote the motor waveform to be natural sinusoidal, greatly reduce the third, fifth and seventh harmonics, and for a single-phase permanent magnet motor, the inherent property of the third harmonic directly affects the waveform and noise of the motor, and is also an important source of loss;

[0028] 3. The magnetic isolation hole is further arranged on the rotor lamination of the present application, which can isolate the magnetic circuit to increase the magnetic resistance, cause local cavities, optimize the air gap magnetic field distribution, and further optimize the load magnetic circuit distribution;

[0029] 4. The anti-magnetic short-circuit magnetic hole is further arranged on the rotor lamination of the present application, which can prevent magnetic short circuit to cause permanent demagnetization, and reduce magnetic leakage at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings are used to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used to explain the embodiments of the present application together with the specific embodiments below, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0031] Figure 1 is a front view of the assembly structure of the single-phase permanent magnet motor rotor provided by an embodiment of the present application;

[0032] Figure 2 is a side view of the assembly structure of the single-phase permanent magnet motor rotor provided by an embodiment of the present application;

[0033] Figure 3 is a schematic view of the overall structure of the rotor lamination provided by an embodiment of the present application;

[0034] Figure 4 is a schematic view of the overall structure of the end plate provided by an embodiment of the present application;

[0035] Figure 5 is a schematic view of the size marking of the rotor lamination provided by an embodiment of the present application;

[0036] Figure 6is a full load output torque curve provided by an embodiment of the present application with angle change;

[0037] Figure 7 is a full load current curve provided by an embodiment of the present application with angle change;

[0038] Figure 8 is an air gap magnetic field distribution provided by an embodiment of the present application with angle change;

[0039] Figure 9 is a THD simulation diagram provided by an embodiment of the present application;

[0040] Figure 10 is a cogging torque distribution provided by an embodiment of the present application with angle change;

[0041] Figure 11 is a motor operation vector diagram provided by an embodiment of the present application;

[0042] Legend: 1, rotor lamination; 2, center shaft; 3, end plate; 4, damping pull rod; 5, pull rod hole; 6, permanent magnet; 7, first weight-reducing vent hole; 8, second weight-reducing vent hole; 9, magnetic concentration hole; 10, magnetic isolation hole; 11, anti-magnetic short-circuit magnetic hole; 12, through hole; 13, cutout; 14, through slot. DETAILED DESCRIPTION

[0043] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the present application will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the drawings structure is only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor. It should be noted that the description of these embodiments is used to help understand the present application, but does not constitute a limitation on the present application.

[0044] Figure 1 is a single-phase permanent magnet motor rotor assembly structure front view provided by an embodiment of the present application. As shown in Figure 1As shown, a single-phase permanent magnet motor rotor includes: a rotor lamination 1, a central shaft 2, and two end plates 3. The two end plates 3 are fixed to the end faces of the rotor lamination 1 by a plurality of damping rods 4. In this embodiment, 12 damping rods 4 are provided, symmetrically distributed around the circumference of the rotor lamination 1. The rotor lamination 1 is provided with 12 rod holes 5, and the 12 damping rods 4 are inserted into the rod holes 5. The end plates 3 are pressed tightly onto the rotor lamination 1 by bolts through the through holes 12 at both ends of the damping rods 4. Therefore, the single-phase permanent magnet motor rotor of this embodiment has high symmetry, high strength, small unilateral magnetic pull, high power density, low noise, and low heat generation. Because the damping rods 4 are embedded in the center, the motor maintains a smooth torque transition through damping elastic deformation in the event of a sudden torque change, reducing the impact on the end bearings and the central shaft 2.

[0045] like Figure 2 As shown, several sets of magnet groups are symmetrically arranged on the rotor lamination 1. The sets of magnet groups are distributed along the circumference of the rotor lamination 1, and each set of magnet groups includes two strip-shaped permanent magnets 6. In this embodiment, a total of 4 sets of magnet groups are arranged, each set having two permanent magnets 6, for a total of eight permanent magnets 6. Between two adjacent sets of magnet groups, the rotor lamination 1 is provided with 3 tie rod holes 5. Among these 3 tie rod holes 5, the distance from the middle tie rod hole 5 to the axis of the rotor lamination 1 is less than the distance from the tie rod holes 5 on both sides to the axis of the rotor lamination 1, and the distance from the tie rod holes 5 on both sides to the axis of the rotor lamination 1 is the same. This arrangement structure makes the rotor height of the single-phase permanent magnet motor symmetrical.

[0046] As a further optimization of this embodiment, such as Figure 3 As shown, a first weight-reducing ventilation hole 7 is provided on the rotor lamination 1 located at the inner end of each permanent magnet 6, and a second weight-reducing ventilation hole 8 is provided on the rotor lamination 1 between the two permanent magnets 6 in each group. At least one magnetic focusing hole 9 and at least one magnetic isolation hole 10 are provided on the rotor lamination 1 between each two adjacent groups of magnets. A magnetic anti-magnetic short-circuit magnetic hole 11 is provided on the rotor lamination 1 located at the outer end of each permanent magnet 6.

[0047] In this embodiment, the first weight-reducing ventilation hole 7 and the anti-magnetic short-circuit magnetic hole 11 are both triangular holes, the second weight-reducing ventilation hole 8 is a round hole, and the magnetic shielding hole 10 is a round hole and / or a square hole.

[0048] Among them, the first weight-reducing ventilation hole 7 and the second weight-reducing ventilation hole 8 can not only reduce the weight of the rotor lamination 1, but also form ventilation cavities during the rotation of the rotor lamination 1, which can quickly remove the heat inside the iron core.

[0049] Among them, the magnetic focusing hole 9 can concentrate the magnetic field generated by the permanent magnet 6, which can make the motor waveform naturally sinusoidal and greatly reduce the third, fifth and seventh harmonics. For single-phase permanent magnet motors, the inherent properties of the third harmonic directly affect the waveform and noise of the motor, and it is also an important source of loss.

[0050] Among them, the magnetic isolation hole 10 can isolate the magnetic circuit, increase magnetic resistance, create local cavitation, optimize the air gap magnetic field distribution, and further optimize the load magnetic circuit distribution.

[0051] Among them, the anti-magnetic short-circuit magnetic hole 11 can prevent permanent demagnetization caused by magnetic short circuit, and at the same time reduce magnetic leakage.

[0052] In this embodiment, as Figure 4 As shown, the end plate 3 is provided with through holes 12 corresponding to the first weight-reducing ventilation hole 7 and the second weight-reducing ventilation hole 8.

[0053] As a further optimization of this embodiment, a magnetic isolation hole 10 is provided between the two first weight-reducing ventilation holes 7 at the inner ends of two adjacent permanent magnets 6 that are not in the same group. The magnetic isolation hole 10 is a square hole, and the distance Q between the magnetic isolation hole 10 and the two first weight-reducing ventilation holes 7 at the inner ends of the two adjacent permanent magnets 6 that are not in the same group ranges from (0.8 mm to 3.5 mm). Figure 5 As shown.

[0054] The magnetic isolation hole 10 can isolate the magnetic circuit, increase magnetic resistance, create local voids, and prevent local short circuits of effective magnetic flux; reduce the density of the cavity here, optimize the distribution of the air gap magnetic field, and further optimize the distribution of the loaded magnetic circuit; it can also further reduce weight, resulting in lightweight lamination; at the same time, the void here forms a ventilation void during rotation, which can quickly remove the heat inside the iron core.

[0055] As a further optimization of this embodiment, the included angle Y between any two adjacent sets of magnets is 90°~116.2°, such as... Figure 5 As shown.

[0056] As a further optimization of this embodiment, two magnetic focusing holes 9 are provided on the rotor lamination 1 between each pair of adjacent magnet groups, and the cross-section of each magnetic focusing hole 9 is elongated, and each magnetic focusing hole 9 is perpendicular to the side wall of the permanent magnet 6 adjacent to the magnetic focusing hole 9.

[0057] like Figure 5 As shown, the vertical distance from each magnetic focusing hole 9 to the inner edge of the permanent magnet 6 adjacent to that magnetic focusing hole 9 is:

[0058] H = L * m;

[0059] In the formula, H is the vertical distance from each magnetic focusing hole 9 to the inner edge of the permanent magnet 6 adjacent to the magnetic focusing hole 9, L is the length of the cross section of each permanent magnet 6, and m is the first coefficient, the value range of the first coefficient m is (0.3, 0.7); in this embodiment, the length L of the cross section of each permanent magnet 6 is (10mm, 65mm), and the width W of the cross section of each permanent magnet 6 is (4.5mm, 30.5mm).

[0060] Meanwhile, the minimum distance between the two magnetic focusing holes 9 between the two permanent magnets 6 in the same group is determined based on the distance between the two permanent magnets 6 in that group;

[0061] The distance between the two permanent magnets 6 in this group is:

[0062] G = k * π * D;

[0063] In the formula, G is the distance between the two permanent magnets 6 in each group, k is the third coefficient, the value of the third coefficient k is (0.05, 0.21), π is pi, and D is the outer diameter of the rotor lamination 1.

[0064] Therefore, the minimum distance between the two magnetic focusing holes 9 between the two permanent magnets 6 in the same group is:

[0065] E = b * G;

[0066] In the formula, E is the minimum distance between the two magnetic holes 9 between the two permanent magnets 6 in the same group, and b is the second coefficient, which takes values ​​in the range of (0.45, 0.7).

[0067] This embodiment optimizes the minimum distance between the two magnetic focusing holes 9, which further enhances the magnetic focusing and guiding effects, improves the air gap magnetic field distribution, improves the voltage waveform, and increases its sinusoidal strength. At the same time, the large amount of effective magnetic flux converges in the middle, further increasing the motor's overload capacity and preventing the "peak clipping" phenomenon. Furthermore, due to the large amount of effective magnetic flux convergence, the voltage regulation rate during the load process is also further optimized, preventing premature magnetic circuit deviation, thereby effectively optimizing the voltage regulation rate and load waveform.

[0068] As a further optimization of this embodiment, a cutout 13 extending along the axial direction of the rotor lamination 1 is provided on the outer wall of the rotor lamination 1 located outside each group of magnets. A through groove 14 is provided in the middle of the cutout 13. The depth of the cutout 13 is less than 10 mm, that is, the depth X of the cutout 13 is (0, 10 mm).

[0069] In this embodiment, the depth of the notch 13 can significantly improve the q-axis reluctance, change the d-axis / q-axis ratio, which is beneficial for reducing reluctance torque, improving the waveform during load operation, and simultaneously increasing the motor's overload capacity. Meanwhile, the through slot 14 further improves radial reluctance, improves q-axis flux, increases the leakage flux path of the d-axis magnetic field, and increases the flux linkage utilization rate. The d-axis magnetic field refers to the magnetic field parallel to the rotor pole axis (i.e., the direction of the permanent magnet poles) in the motor; it is mainly related to the motor's excitation flux and reflects the motor's magnetic field strength. The q-axis magnetic field refers to the magnetic field perpendicular to the rotor pole axis; it is mainly related to the motor's torque generation and reflects the motor's ability to generate mechanical force.

[0070] The test parameters of the single-phase permanent magnet motor equipped with the rotor of the present invention are shown in the table below:

[0071]

[0072] exist Figure 6 In the diagram, the horizontal axis represents the angular position, and the vertical axis represents the output torque, with units of N*m; Figure 7 In the diagram, the horizontal axis represents the angular position, and the vertical axis represents the current, with the unit being amperes (A). Figure 8 In the figure, the horizontal axis represents the angular position, and the vertical axis represents the airgap flux density, with units of tons (T). Figure 9 In the diagram, the horizontal axis represents the harmonic order, and the vertical axis represents the harmonic amplitude. Figure 10 In the figure, the horizontal axis represents the angular position, and the vertical axis represents the cogging torque, with the unit being N*m.

[0073] From the appendix Figures 6-10 As can be seen from the simulation and measured data, the output voltage of this invention is a single-phase pure sine wave, and the total voltage harmonic distortion rate (THDu) is 3.72 in simulation and 4.09 in measurement, both less than the 10% standard for military standard single-phase excitation motors. Furthermore, this invention uses permanent magnets as the excitation source, eliminating excitation circuit losses and greatly increasing motor efficiency. Due to the use of permanent magnets as the excitation source, the load angle is small during operation, only 18-22 degrees. Figure 11 It can be seen that the motor power factor reaches 0.98 or higher.

[0074] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A rotor for a single-phase permanent magnet motor, characterized in that, include: Rotor lamination (1), on which several sets of magnets are symmetrically arranged, the sets of magnets are distributed along the circumference of the rotor lamination (1), and each set of magnets includes two strip-shaped permanent magnets (6). The rotor lamination (1) located at the inner end of each permanent magnet (6) is provided with a first weight-reducing ventilation hole (7), and the rotor lamination (1) between each group of two permanent magnets (6) is provided with a second weight-reducing ventilation hole (8). The rotor lamination (1) between each two adjacent groups of magnets is provided with at least one magnetic focusing hole (9) and at least one magnetic isolation hole (10). The rotor lamination (1) located at the outer end of each permanent magnet (6) is provided with a magnetic anti-magnetic short-circuit magnetic hole (11). A cut (13) extending along the axial direction of the rotor lamination (1) is provided on the outer wall of the rotor lamination (1) located outside the magnet group of each group, and a through groove (14) is provided in the middle of the cut (13); the depth of the cut (13) is less than 10 mm. Two magnetic focusing holes (9) are provided on the rotor lamination (1) between each pair of adjacent magnet groups, and the cross-section of each magnetic focusing hole (9) is elongated, and each magnetic focusing hole (9) is perpendicular to the side wall of the permanent magnet (6) adjacent to the magnetic focusing hole (9); the vertical distance from each magnetic focusing hole (9) to the inner edge of the permanent magnet (6) adjacent to the magnetic focusing hole (9) is: ； In the formula, H is the vertical distance from each magnetic hole (9) to the inner edge of the permanent magnet (6) adjacent to the magnetic hole (9), L is the length of the cross section of each permanent magnet (6), and m is the first coefficient, the value range of the first coefficient m is (0.3, 0.7). The minimum distance between the two magnetic focusing holes (9) between two permanent magnets (6) in the same group is determined based on the distance between the two permanent magnets (6) in that group; The distance between the two permanent magnets (6) in this group is: ； In the formula, G is the distance between the two permanent magnets (6) in each group, k is the third coefficient, the value range of the third coefficient k is (0.05, 0.21), π is pi, and D is the outer diameter of the rotor lamination (1); Therefore, the minimum distance between the two magnetic focusing holes (9) between the two permanent magnets (6) in the same group is: ； In the formula, E is the minimum distance between the two magnetic holes (9) between the two permanent magnets (6) in the same group, and b is the second coefficient, the value range of the second coefficient b is (0.45, 0.7).

2. The single-phase permanent magnet motor rotor according to claim 1, characterized in that, Also includes: A central rotating shaft (2) is inserted into a rotor lamination (1). Both ends of the rotor lamination (1) are provided with end pressure plates (3). The end pressure plates (3) are fixed to the end face of the rotor lamination (1) by several damping rods (4). The end pressure plates (3) are provided with through holes (12) corresponding to the first weight-reducing ventilation hole (7) and the second weight-reducing ventilation hole (8).

3. The single-phase permanent magnet motor rotor according to claim 1, characterized in that, The first weight-reducing ventilation hole (7) and the anti-magnetic short-circuit magnetic hole (11) are both triangular holes, the second weight-reducing ventilation hole (8) is a round hole, and the magnetic shielding hole (10) is a round hole and / or a square hole.

4. The single-phase permanent magnet motor rotor according to claim 3, characterized in that, There is a magnetic isolation hole (10) between the two first weight reduction ventilation holes (7) at the inner ends of two adjacent permanent magnets (6) that are not in the same group. The magnetic isolation hole (10) is a square hole, and the distance Q between the magnetic isolation hole (10) and the two first weight reduction ventilation holes (7) at the inner ends of the two adjacent permanent magnets (6) that are not in the same group is in the range of (0.8mm, 3.5mm).

5. The single-phase permanent magnet motor rotor according to claim 1, characterized in that, The included angle between any two adjacent sets of magnets is 90° to 116.2°.

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