Motor rotor and motor

Abstract

The utility model belongs to the technical field of motors, and discloses a motor rotor and a motor, the spacing distance between a first bottom groove and a through hole is H1, the groove width of the first bottom groove is W1, and the spacing distance between a first side groove and a first side groove of another magnetic pole unit is C1; the spacing distance between the second bottom groove and the first bottom groove is H2, the groove width of the second bottom groove is W2, and the spacing distance between the second side groove and the first side groove is C2; the width of the communicating area of the two third side grooves is W3, the spacing distance between the communicating area and the second bottom groove is H3, and the spacing distance between the third side grooves and the second side groove is C3; wherein C3 is equal to H3, through the reasonably-arranged magnetic slots and permanent magnets, the motor can meet the requirement for outputting torque, the torque fluctuation is small, motor vibration is reduced, and noise is lowered.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to motor rotors and motors. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) offer advantages such as high torque density, high efficiency, and strong stability. In PMSMs, the permanent magnet material has a crucial impact on motor performance. Auxiliary reluctance motors (ARRMs) utilize inexpensive permanent magnet materials to reduce motor costs. To ensure performance meets requirements, besides maximizing the number of permanent magnets within a limited space, it's also necessary to increase the inductance difference between the d-axis and q-axis to achieve the desired electromagnetic torque. The inductance value is significantly affected by magnetic circuit saturation; when the magnetic circuit is saturated, the motor torque fluctuates greatly. Therefore, a well-designed magnetic circuit along the d-axis and q-axis can reduce torque fluctuations in PMSMs, decrease motor vibration, and lower noise. Utility Model Content

[0003] The purpose of this invention is to provide a motor rotor and a motor, and to improve the layout of the magnetic pole unit to reduce motor vibration and noise.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] In a first aspect, a motor rotor is provided, including a rotor core, wherein a through hole is provided in the middle of the rotor core, and a plurality of magnetic pole units are arranged around the periphery of the rotor core, each magnetic pole unit having a first magnetic slot, a second magnetic slot, and a third magnetic slot spaced outward in a radial direction:

[0006] The first magnetic groove includes a first bottom groove and two first side grooves. The two first side grooves are symmetrically arranged on both sides of the first bottom groove. The distance between the first bottom groove and the through hole is H1. The groove width of the first bottom groove is W1. The distance between the first side groove and the first side groove of an adjacent magnetic pole unit is C1.

[0007] The second magnetic groove includes a second bottom groove and two second side grooves. The two second side grooves are symmetrically arranged on both sides of the second bottom groove. The distance between the second bottom groove and the first bottom groove is H2. The groove width of the second bottom groove is W2. The distance between the second side groove and the first side groove is C2.

[0008] The third magnetic groove includes two interconnected and symmetrical third side grooves about the d-axis. The width of the connecting area between the two third side grooves is W3. The distance between the connecting area and the second bottom groove is H3. The distance between the third side groove and the second side groove is C3.

[0009] in, C3 = H3, W1>W2>W3, C1>C2>C3, H1>H2>H3;

[0010] The first bottom groove, the two first side grooves, the second bottom groove, the two second side grooves, and the two third side grooves are all embedded with permanent magnets.

[0011] As an optional technical solution, the permanent magnet is a ferrite.

[0012] As an optional technical solution, both the first bottom groove and the second bottom groove are straight, and the first bottom groove is parallel to the second bottom groove.

[0013] As an optional technical solution, the two first side grooves are respectively connected to the two ends of the first bottom groove.

[0014] As an optional technical solution, the permanent magnet embedded in the first bottom groove and the permanent magnet embedded in the first side groove are spaced apart.

[0015] As an optional technical solution, the two second side grooves are respectively connected to the two ends of the second bottom groove.

[0016] As an optional technical solution, the permanent magnet embedded in the second bottom groove and the permanent magnet embedded in the second side groove are spaced apart.

[0017] As an optional technical solution, the permanent magnet embedded in one of the third side slots is spaced apart from the permanent magnet embedded in the other third side slot.

[0018] As an optional technical solution, the width of the first bottom groove is equal to the width of the first side groove;

[0019] And / or, the width of the second bottom groove is equal to the width of the second side groove;

[0020] And / or, the widths of the two third side slots are equal.

[0021] Secondly, an electric motor is provided, including a motor rotor as described above.

[0022] The beneficial effects of this utility model are:

[0023] This utility model provides a motor rotor and a motor. Through the reasonable arrangement of magnetic slots and permanent magnets, the motor can meet the output torque requirements with small torque fluctuations, reduce motor vibration, and lower noise. Attached Figure Description

[0024] Figure 1 This is a partial view of the motor rotor of this utility model;

[0025] Figure 2 This is a graph showing the changes in the d-axis and q-axis inductance of the motor rotor of this utility model as a function of current.

[0026] Figure 3 This is a comparison diagram of torque fluctuations in this utility model.

[0027] In the picture:

[0028] 11. Through hole; 12. First magnetic groove; 121. First bottom groove; 122. First side groove; 13. Second magnetic groove; 131. Second bottom groove; 132. Second side groove; 14. Third magnetic groove; 141. Third side groove; 142. Connecting area; 15. Permanent magnet; 16. First magnetic channel; 17. Second magnetic channel; 18. Third magnetic channel. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0030] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and 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. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0033] Figure 1 Two magnetic pole units are shown. In one magnetic pole unit, each magnetic slot is embedded with a permanent magnet 15, while in the other magnetic pole unit, none of the magnetic slots are embedded with a permanent magnet 15. The magnetic slots referred to in this embodiment include a first magnetic slot, a second magnetic slot, and a third magnetic slot.

[0034] like Figure 1 As shown, this embodiment provides a motor rotor, which includes a rotor core. A through hole 11 is provided in the center of the rotor core. Multiple magnetic pole units are arranged around the periphery of the rotor core. Each magnetic pole unit has a first magnetic groove 12, a second magnetic groove 13, and a third magnetic groove 14 spaced radially outwards. The first magnetic groove 12 includes a first bottom groove 121 and two first side grooves 122. The two first side grooves 122 are symmetrically arranged on both sides of the first bottom groove 121. The distance between the first bottom groove 121 and the through hole 11 is H1, the groove width of the first bottom groove 121 is W1, and the distance between the first side groove 122 and the first side groove 122 of an adjacent magnetic pole unit is C1. The second magnetic groove 13 includes a second bottom groove 131 and two second side grooves 132. The two second side grooves 132 are symmetrically arranged on both sides of the second bottom groove 131. The distance between the second bottom groove 131 and the first bottom groove 121 is H2, the groove width of the second bottom groove 131 is W2, and the distance between the second side groove 132 and the first side groove 122 is C2. The third magnetic groove 14 includes two connected and symmetrical third side grooves 141 about the d-axis. The width of the connecting area 142 of the two third side grooves 141 is W3, the distance between the connecting area 142 and the second bottom groove 131 is H3, and the distance between the third side groove 141 and the second side groove 132 is C3. C3 = H3, W1>W2>W3, C1<C2<C3, H1>H2>H3; the first bottom groove 121, the two first side grooves 122, the second bottom groove 131, the two second side grooves 132 and the two third side grooves 141 are all equipped with permanent magnets 15.

[0035] In this embodiment, the distance H1 between the first bottom groove 121 and the through hole 11 means that the shortest distance from the first bottom groove 121 to the inner wall of the through hole 11 along the radial direction of the rotor core is H1; the groove width W1 of the first bottom groove 121 means that the width of the first bottom groove 121 along the radial direction of the rotor core is W1; between two adjacent magnetic pole units, the two first side grooves 122 are parallel to each other and are spaced apart by a distance C1, and the area between the two first side grooves 122 is the first magnetic channel 16, and the width of the first magnetic channel 16 is C1.

[0036] In this embodiment, the interval H2 between the second bottom groove 131 and the first bottom groove 121 means that, in the same magnetic pole unit, along the radial direction of the rotor core, the second bottom groove 131 and the first bottom groove 121 are arranged parallel to each other and the interval is H2; the groove width W2 of the second bottom groove 131 means that, along the radial direction of the rotor core, the width of the second bottom groove 131 is W2; the interval C2 between the second side groove 132 and the first side groove 122 means that, in the same magnetic pole unit and on the same side of the d-axis, the second side groove 132 and the first side groove 122 are parallel to each other and the interval is C2, the area between the second side groove 132 and the first side groove 122 is the second magnetic channel 17, and the width of the second magnetic channel 17 is C2.

[0037] In this embodiment, the two third side slots 141 of the third magnetic slot 14 are connected and form a V-shape. The width W3 of the connecting area 142 of the two third side slots 141 means that in the same magnetic pole unit, the width of the connecting area 142 of the two third side slots 141 along the radial direction of the rotor core is W3. The distance H3 between the connecting area 142 and the second bottom slot 131 means that the bottom edge of the connecting area 142 is parallel to the second bottom slot 131 and the distance between them is H3. The distance C3 between the third side slot 141 and the second side slot 132 means that in the same magnetic pole unit and on the same side of the d-axis, the third side slot 141 and the second side slot 132 are parallel to each other and the distance between them is C3. The area between the third side slot 141 and the second side slot 132 is the third magnetic channel 18, and the width of the third magnetic channel 18 is C3.

[0038] To facilitate the installation of permanent magnets, the permanent magnets 15 are fitted with each magnetic slot with a clearance. The thickness of the permanent magnet 15 embedded in the first bottom slot 121 is slightly less than the width of the first bottom slot 121; the thickness of the permanent magnet 15 embedded in the first side slot 122 is slightly less than the width of the first side slot 122; the thickness of the permanent magnet 15 embedded in the second bottom slot 131 is slightly less than the width of the second bottom slot 131; the thickness of the permanent magnet 15 embedded in the second side slot 132 is slightly less than the width of the second side slot 132; and the thickness of the permanent magnet 15 embedded in the third side slot 141 is slightly less than the width of the third side slot 141.

[0039] This embodiment, through the reasonable arrangement of magnetic slots and permanent magnets 15, enables the motor to meet the output torque requirements with small torque fluctuations, thereby reducing motor vibration and noise.

[0040] The electromagnetic torque of the motor is Because the remanence of permanent magnet 15 is low, the magnetic flux φ f The permanent magnet torque of the motor is relatively small. Smaller, while reluctance torque It can reach over 60%, and the magnitude of the reluctance torque is related to the inductance value L. d and L q Relatedly, due to the nonlinearity of the rotor core's permeability, the magnetic circuit saturates as the stator current increases, and the inductance decreases due to magnetic circuit saturation. Because of the difference between the d-axis and q-axis magnetic circuits, the effects of magnetic circuit saturation on the d-axis and q-axis inductance are also different. When the permanent magnet 15 is ferrite, the curves showing the changes in d-axis and q-axis inductance with current are attached. Figure 2 As shown.

[0041] like Figure 2 As shown, with the increase of current, the q-axis inductance decreases by 19.8% and the d-axis inductance decreases by 11.1%. The change of current has a great impact on the q-axis inductance. This is because with the increase of current, the saturation of the motor's magnetic circuit increases, and the magnetic reluctance of the magnetic circuit increases. The magnetic circuit always moves along the direction of lower magnetic reluctance. In this embodiment, C1 < C2 < C3, shortening the length of the magnetic circuit reduces the magnetic reluctance.

[0042] Because the permanent magnet 15 has low remanence, in order to meet the performance requirements of the motor, it is necessary to set as many permanent magnets 15 as possible, increase the thickness of the permanent magnet 15, and improve the motor torque. However, when the thickness of the permanent magnet 15 reaches a certain level, the torque amplitude of the motor will gradually slow down, and the motor torque will tend to saturate and stabilize. Therefore, the thickness of the permanent magnet 15 and the magnetic channel have an important impact on the torque fluctuation and vibration noise of the motor.

[0043] In the motor of this embodiment, when the stator is the same, the outer diameter of the rotor core and the inner diameter of the through hole 11 are determined, the space for setting the permanent magnet 15 is limited. By designing the proportional relationship between the magnetic guiding channels in the d-axis and q-axis directions and the thickness of the permanent magnet 15, an optimal solution is achieved. C3 = H3, W1 > W2 > W3, C1 < C2 < C3, H1 > H2 > H3. The specific simulation data is shown in the table below.

[0044]

[0045]

[0046] Scheme 1's H1, H2, H3, C1, C2, and C3 meet the requirements of this embodiment. Schemes 2, 3, and 4 change one or more parameters. Within the above parameter range, with the same current, the torque fluctuation rate decreases from 23.63% to 2.83%. Without skewed poles or slots, the torque fluctuation can be reduced to less than 5%. Furthermore, with the same amount of copper wire, the amount of permanent magnet 15 is reduced by 17%, saving costs. A comparison of the motor's torque fluctuation before and after optimization is provided. Figure 3 As shown.

[0047] In this embodiment, both the first bottom groove 121 and the second bottom groove 131 are straight lines, and the first bottom groove 121 and the second bottom groove 131 are parallel. The straight first bottom groove 121 and the straight second bottom groove 131 are easier to manufacture and have lower production costs; in the same magnetic pole unit, the first bottom groove 121 and the second bottom groove 131 are parallel.

[0048] In this embodiment, the permanent magnet 15 is ferrite. In other embodiments, the permanent magnet 15 is made of neodymium iron boron. Neodymium iron boron has high remanence; however, it is a non-renewable resource and expensive. Ferrite is readily available and inexpensive, but it has low remanence and low magnetic flux. However, this embodiment, through the rational layout of the magnetic slots, embeds the ferrite into the slots, thereby reducing costs while meeting the motor performance requirements. This allows the motor to achieve sufficient output torque with minimal torque fluctuation, reducing motor vibration and noise.

[0049] In this embodiment, the two first side slots 122 are respectively connected to the two ends of the first bottom slot 121. In the same magnetic pole unit, the first bottom slot 121 and the two first side slots 122 are connected to form a trapezoidal shape, which is easier to manufacture and has lower production costs.

[0050] Optionally, the outer peripheral wall of the rotor core is wound with carbon fiber or fiberglass to enhance the structural strength of the rotor core. When the first bottom slot 121 and the two first side slots 122 are connected, carbon fiber or fiberglass is wound around the outer periphery of the rotor core to ensure that the structural strength meets the requirements.

[0051] In some other embodiments, neither of the two first side slots 122 is connected to the first bottom slot 121. In the same first magnetic slot 12, the first side slot 122 and the first bottom slot 121 are separated by the wall of the rotor core, which has the function of strengthening the structure.

[0052] In this embodiment, the permanent magnet 15 embedded in the first bottom groove 121 and the permanent magnet 15 embedded in the first side groove 122 are spaced apart. The first magnetic groove 12 is provided with three permanent magnets 15, and the three permanent magnets 15 do not contact each other.

[0053] In this embodiment, the two second side slots 132 are respectively connected to the two ends of the second bottom slot 131. In the same magnetic pole unit, the second bottom slot 131 and the two second side slots 132 are connected to form a trapezoidal shape, which is easier to manufacture and has lower production costs. When the second side slots 132 are connected to the second bottom slot 131, the structural strength of the rotor core may decrease. In order to ensure that the structural strength meets the requirements, carbon fiber or fiberglass is wound around the outer periphery of the rotor core.

[0054] In some other embodiments, neither of the two second side slots 132 is connected to the second bottom slot 131. In the same second magnetic slot 13, the second side slot 132 and the second bottom slot 131 are separated by the wall of the rotor core, which serves to strengthen the structure.

[0055] In this embodiment, the permanent magnet 15 embedded in the second bottom groove 131 and the permanent magnet 15 embedded in the second side groove 132 are spaced apart. The second magnetic groove 13 is provided with three permanent magnets 15, and the three permanent magnets 15 do not contact each other.

[0056] In this embodiment, the permanent magnet 15 embedded in one of the third side slots 141 is spaced apart from the permanent magnet 15 embedded in the other third side slot 141. Two permanent magnets 15 are provided in the third magnetic slot 14, and the two permanent magnets 15 do not contact each other.

[0057] In this embodiment, the width of the first bottom groove 121 is equal to the width of the first side groove 122.

[0058] In this embodiment, the width of the second bottom groove 131 is equal to the width of the second side groove 132.

[0059] In this embodiment, the widths of the two third side grooves 141 are equal.

[0060] This embodiment also provides a motor, including the motor rotor as described above.

[0061] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An electric motor rotor, comprising a rotor core, wherein a through hole (11) is provided in the middle of the rotor core, and a plurality of magnetic pole units are arranged around the periphery of the rotor core, each magnetic pole unit having a first magnetic groove (12), a second magnetic groove (13), and a third magnetic groove (14) spaced outwardly in a radial direction, characterized in that: The first magnetic groove (12) includes a first bottom groove (121) and two first side grooves (122). The two first side grooves (122) are symmetrically arranged on both sides of the first bottom groove (121). The distance between the first bottom groove (121) and the through hole (11) is H1. The groove width of the first bottom groove (121) is W1. The distance between the first side groove (122) and the first side groove (122) of an adjacent magnetic pole unit is C1. The second magnetic groove (13) includes a second bottom groove (131) and two second side grooves (132). The two second side grooves (132) are symmetrically arranged on both sides of the second bottom groove (131). The distance between the second bottom groove (131) and the first bottom groove (121) is H2. The groove width of the second bottom groove (131) is W2. The distance between the second side groove (132) and the first side groove (122) is C2. The third magnetic groove (14) includes two interconnected and symmetrical third side grooves (141) about the d-axis. The width of the connecting area (142) of the two third side grooves (141) is W3. The distance between the connecting area (142) and the second bottom groove (131) is H3. The distance between the third side groove (141) and the second side groove (132) is C3. in, C3 = H3, W1>W2>W3, C1>C2>C3, H1>H2>H3; The first bottom groove (121), the two first side grooves (122), the second bottom groove (131), the two second side grooves (132) and the two third side grooves (141) are all embedded with permanent magnets (15).

2. The motor rotor according to claim 1, characterized in that, The permanent magnet (15) is a ferrite.

3. The motor rotor according to claim 1, characterized in that, Both the first bottom groove (121) and the second bottom groove (131) are straight lines, and the first bottom groove (121) and the second bottom groove (131) are parallel.

4. The motor rotor according to claim 1, characterized in that, The two first side grooves (122) are respectively connected to the two ends of the first bottom groove (121).

5. The motor rotor according to claim 4, characterized in that, The permanent magnet (15) embedded in the first bottom groove (121) and the permanent magnet (15) embedded in the first side groove (122) are spaced apart.

6. The motor rotor according to claim 1, characterized in that, The two second side grooves (132) are respectively connected to the two ends of the second bottom groove (131).

7. The motor rotor according to claim 6, characterized in that, The permanent magnet (15) embedded in the second bottom groove (131) and the permanent magnet (15) embedded in the second side groove (132) are spaced apart.

8. The motor rotor according to claim 1, characterized in that, The permanent magnet (15) embedded in one of the third side slots (141) is spaced apart from the permanent magnet (15) embedded in the other third side slot (141).

9. The motor rotor according to claim 1, characterized in that, The width of the first bottom groove (121) is equal to the width of the first side groove (122); And / or, the width of the second bottom groove (131) is equal to the width of the second side groove (132); And / or, the widths of the two third side grooves (141) are equal.

10. An electric motor, characterized in that, Includes the motor rotor as described in any one of claims 1-9.

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