Rotor, motor and household appliance

Abstract

The utility model discloses a rotor, a motor and a household electrical appliance, and relates to the technical field of motors. The rotor comprises the yoke part and the plurality of permanent magnets, the plurality of grooves are formed in the inner side wall of the yoke part, and the plurality of permanent magnets are mounted in the corresponding grooves, so that the grooves can play a role in positioning, the permanent magnets are convenient to mount, and the mounting efficiency is improved. As the grooves are formed by recessing the inner side of the yoke part, after the rotor provided by the embodiment of the utility model is applied to the motor, the rotor can be matched with rotors with the same size and model without increasing the overall dimension of the motor. The permanent magnets protrude towards one sides of the grooves, so that the sizes of the permanent magnets can be increased, and the magnetic field intensity is improved; and the magnetic lines of the permanent magnets are gathered on one side close to the motor air gap, so that the air gap flux density can be improved, the saturation degree of the rotor is reduced, and the output power of the motor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to a rotor, a motor and a household appliance. Background Art

[0002] The outer rotor permanent magnet motor includes a rotor and a stator, and the rotor is sleeved on the outside of the stator. The rotor includes a circular yoke and a plurality of permanent magnets, and the plurality of permanent magnets are arranged on the inner side of the yoke and around the stator. With the above scheme, when the outer diameter of the motor is fixed, the volume of the permanent magnet is small, the magnetic field strength and the air gap flux density are low, resulting in a reduction in the output power of the motor. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a rotor that increases the volume of the permanent magnet without substantially changing the outer diameter of the motor, thereby increasing the magnetic field strength and air gap flux density, and thus increasing the output power of the motor.

[0004] The utility model also provides a motor and a household appliance having the rotor.

[0005] According to the rotor of the first aspect of the utility model, the rotor rotates around the rotation axis and includes: an annular yoke, the inner side wall of the yoke is provided with a plurality of grooves, and the plurality of grooves are arranged around the rotation axis; a plurality of permanent magnets, the number of the permanent magnets and the number of the grooves are the same, the plurality of permanent magnets are respectively installed in the corresponding grooves, the permanent magnets protrude toward one side of the groove, and at least part of the structure of the permanent magnets abuts against the inner wall of the groove.

[0006] The rotor according to the embodiment of the utility model has at least the following beneficial effects:

[0007] By setting a plurality of grooves on the inner side wall of the yoke, a plurality of permanent magnets are installed in the corresponding grooves, so that the grooves can play a positioning role, which is convenient for installing the permanent magnets and improves the installation efficiency. Since the grooves are formed by the inner depression of the yoke, when the rotor of the embodiment of the utility model is applied to the motor, it can match the rotor of the same size model without increasing the external dimensions of the motor. The permanent magnet protrudes toward one side of the groove, which can increase the volume of the permanent magnet to increase the magnetic field strength; and the magnetic lines of force of the permanent magnet are gathered on the side close to the air gap of the motor, which can increase the air gap magnetic density, reduce the saturation of the rotor, and thus increase the output power of the motor.

[0008] According to some embodiments of the present invention, a side of the permanent magnet facing the groove is a convex first arc surface, and / or a side of the permanent magnet facing the rotation axis is concave to form a second arc surface.

[0009] According to some embodiments of the present invention, along the radial direction of the rotor, the thickness of the thickest part of the yoke is hx1, and the thickness of the thinnest part of the yoke is hx2, satisfying: 0.05≤hx2 / hx1≤0.95.

[0010] According to some embodiments of the present invention, along the circumference of the rotor, the minimum distance between two adjacent grooves is wx1, and the maximum opening width of the groove is wx2, satisfying: 0.05≤wx2 / (wx1+wx2)≤0.95.

[0011] According to some embodiments of the present invention, along the circumferential direction of the rotor, the maximum width of the permanent magnet is wx3, and the maximum opening width of the groove is wx2, satisfying: 0.05≤wx2 / wx3≤0.95.

[0012] According to some embodiments of the utility model, along the radial direction of the rotor, the thickness of the thickest part of the yoke is hx1, the thickness of the thinnest part of the yoke is hx2, and the maximum thickness of the permanent magnet is hx3, satisfying: 0.05≤hx1 / (hx3+hx2)≤0.95.

[0013] According to some embodiments of the utility model, the yoke includes multiple first sections and multiple second sections, two adjacent first sections are connected by one second section, the groove is located in the first section, and parts of two adjacent permanent magnets protruding from the groove along the circumference of the rotor are abutted against each other, and a gap is formed between the inner side walls of the second sections.

[0014] According to some embodiments of the present invention, the width of the gap gradually decreases along a direction approaching the rotation axis.

[0015] According to some embodiments of the present invention, at least one end of the permanent magnet along the circumference of the rotor is provided with a fillet, and the radius of the fillet is R, satisfying: 0.3mm≤R≤4mm.

[0016] According to some embodiments of the present invention, the yoke includes a plurality of arc segments arranged around the rotation axis, the inner side walls of the arc segments are recessed to form the grooves, and the outer side walls of the arc segments protrude outwards.

[0017] According to some embodiments of the present invention, the yoke further includes a plurality of connecting segments, and adjacent arc segments are connected by the connecting segments.

[0018] According to some embodiments of the present invention, along the radial direction of the rotor, the maximum thickness of the connecting segment is hy1, and the maximum thickness of the arc segment is hy2, satisfying: hy1≥hy2.

[0019] According to some embodiments of the present invention, along the circumference of the rotor, the maximum width of the arc segment is wy1, and the maximum width of the connecting segment is wy2, satisfying: wy1≥wy2.

[0020] According to some embodiments of the present invention, the maximum thickness between the maximum inscribed circle of the rotor and the outer side wall of the yoke is hy3, and the minimum thickness between the maximum inscribed circle of the rotor and the outer side wall of the yoke is hy4, satisfying: hy3>hy4.

[0021] The motor according to the second embodiment of the utility model comprises a stator and the rotor described in the above embodiment, wherein the rotor is arranged around the outer side of the stator.

[0022] The motor according to the embodiment of the utility model has at least the following beneficial effects:

[0023] By adopting the rotor of the first aspect embodiment, the rotor is provided with a plurality of grooves on the inner side wall of the yoke, and a plurality of permanent magnets are installed in the corresponding grooves, so that the grooves can play a positioning role, which is convenient for installing the permanent magnets and improves the installation efficiency. Since the grooves are formed by the inner depression of the yoke, when the rotor of the utility model embodiment is applied to the motor, it can match the rotor of the same size model without increasing the external dimensions of the motor. The permanent magnet protrudes toward one side of the groove, which can increase the volume of the permanent magnet to increase the magnetic field strength; and the magnetic lines of force of the permanent magnet are gathered on the side close to the air gap of the motor, which can increase the air gap magnetic density, reduce the saturation of the rotor, and thus increase the output power of the motor.

[0024] According to some embodiments of the present invention, the stator includes a stator core, the stator core includes tooth tops, along the circumference of the rotor, the maximum width of the tooth tops is wx4, the maximum width of the permanent magnet is wx3, and the following condition is satisfied: 0.7≤wx4 / wx3≤1.3.

[0025] According to some embodiments of the present invention, the maximum axial length of the yoke is Lx1, the maximum axial length of the stator is Lx2, and the maximum axial length of the permanent magnet is Lx3, satisfying: 0<Lx2 / Lx1≤1, 0<Lx1 / Lx3≤1.

[0026] A household appliance according to an embodiment of the third aspect of the utility model comprises the motor described in the above embodiment.

[0027] The household appliance according to the embodiment of the utility model has at least the following beneficial effects:

[0028] By adopting the motor of the second aspect embodiment, the rotor of the motor is provided with a plurality of grooves on the inner side wall of the yoke, and a plurality of permanent magnets are installed in the corresponding grooves, so that the grooves can play a positioning role, which is convenient for installing the permanent magnets and improves the installation efficiency. Since the grooves are formed by the inner depression of the yoke, when the rotor of the utility model embodiment is applied to the motor, it can match the rotor of the same size model without increasing the external dimensions of the motor. The permanent magnet protrudes toward one side of the groove, which can increase the volume of the permanent magnet to increase the magnetic field strength; and the magnetic lines of force of the permanent magnet are gathered on the side close to the air gap of the motor, which can increase the air gap magnetic density, reduce the saturation degree of the rotor, and thus increase the output power of the motor and improve the performance of the household appliance.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0031] Figure 1 It is a structural schematic diagram of a motor in one embodiment of the utility model;

[0032] Figure 2 It is a structural schematic diagram of a yoke of an embodiment of the utility model;

[0033] Figure 3 This is a schematic diagram of the structure of a rotor in one embodiment of the utility model;

[0034] Figure 4 yes Figure 3 The enlarged view of point A in the middle;

[0035] Figure 5 It is a structural schematic diagram of a stator of an embodiment of the utility model;

[0036] Figure 6 It is a schematic structural diagram of a rotor of another embodiment of the utility model;

[0037] Figure 7 It is a structural schematic diagram of a yoke of another embodiment of the utility model;

[0038] Figure 8 It is a schematic structural diagram of a rotor of another embodiment of the utility model;

[0039] Fig. 9 It is a structural schematic diagram of a yoke of another embodiment of the utility model;

[0040] Fig.10It is a schematic diagram of the effect of different fillet sizes of permanent magnets on the cogging torque in one embodiment of the utility model.

[0041] Reference numerals:

[0042] Rotor 100; yoke 110; groove 111; arc segment 112; connecting segment 113; first segment 114; second segment 115; permanent magnet 120; fillet 121; first arc surface 122; second arc surface 123; gap 130;

[0043] stator 200 ; stator core 210 ; tooth top 211 ; winding 212 ; tooth portion 213 . DETAILED DESCRIPTION

[0044] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0045] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0046] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0047] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0048] Reference Figure 1 , Figure 2 and Figure 3As shown, a rotor 100 of an embodiment of the utility model is an outer rotor and can rotate around the axis of rotation. The rotor 100 of the embodiment of the utility model includes a yoke 110 and a plurality of permanent magnets 120, the yoke 110 is annular, and the inner side wall of the yoke 110 is provided with a plurality of grooves 111, and the plurality of grooves 111 are arranged around the axis of rotation. Among them, the groove 111 is a structure formed by the inner side wall of the yoke 110 being recessed. The number of permanent magnets 120 is the same as the number of grooves 111, and the plurality of permanent magnets 120 are respectively installed in the corresponding grooves 111, and the permanent magnets 120 protrude toward one side of the groove 111 and abut against the inner wall of the groove 111. Among them, part of the structure of the permanent magnet 120 is located in the groove 111, and the other part of the structure is located outside the groove 111.

[0049] By providing a plurality of grooves 111 on the inner wall of the yoke 110, a plurality of permanent magnets 120 are installed in the corresponding grooves 111, so that the grooves 111 can play a positioning role, which facilitates the installation of the permanent magnets 120 and improves the installation efficiency. Since the grooves 111 are formed by the inner depression of the yoke 110, when the rotor 100 of the embodiment of the utility model is applied to the motor, it can match the rotor 100 of the same size model without increasing the external dimensions of the motor. The permanent magnet 120 protrudes toward one side of the groove 111, which can increase the volume of the permanent magnet 120 to increase the magnetic field strength. Figure 3 and Figure 4 As shown in FIG. 1 , the solid lines inside the yoke 110 and the permanent magnet 120 represent magnetic lines of force. Figure 3 and Figure 4 It can be seen that the magnetic lines of force of the permanent magnet 120 are gathered on the side close to the air gap of the motor. The air gap of the motor refers to the gap between the stator 200 and the rotor 100. Therefore, the air gap magnetic density can be improved, and the saturation degree of the rotor 100 can be reduced, thereby improving the output power of the motor.

[0050] Reference Figure 2 , Figure 3 and Figure 4As shown, in the embodiment of the utility model, the side of the permanent magnet 120 facing the groove 111 is a convex first arc surface 122, and the side of the permanent magnet 120 facing the rotation axis is concave to form a second arc surface 123. The first arc surface 122 can be composed of multiple arc surfaces with different curvatures, or it can also be a circular arc surface; the second arc surface 123 can also be composed of multiple arc surfaces with different curvatures, or the second arc surface 123 is a circular arc surface. Take the first arc surface 122 and the second arc surface 123 as an example, wherein the radius of the first arc surface 122 is smaller than the radius of the second arc surface 123, and the first arc surface 122 and the second arc surface 123 are transitionally connected by a fillet 121. It can be understood that the use of the arc surface solution can reduce the severity of the change of the magnetic line of force, make its transition smoother, thereby reducing the cogging torque and pulsating torque. At the same time, it is conducive to guiding the magnetic lines of force of the permanent magnet 120 to gather on one side of the air gap to improve the air gap magnetic density, and can also simplify the manufacturing process and improve production efficiency. When the second arc surface 123 is an arc surface, the radius of the arc surface is the same as the maximum inscribed circle radius of the rotor 100, which can reduce the variation range of the motor air gap width to improve the uniformity of the magnetic field distribution, making the rotor 100 run more smoothly and reducing vibration and noise.

[0051] It should be noted that, in another embodiment, the side surface of the permanent magnet 120 facing the groove 111 may also be a plane, or a plurality of planes with different slopes connected in sequence. The side surface of the permanent magnet 120 facing the rotation axis may also be a plane, a convex curved surface, or a plurality of planes with different slopes connected in sequence, and a suitable solution may be selected according to the actual situation.

[0052] Reference Figure 2As shown, in the embodiment of the present invention, along the radial direction of the rotor 100, the thickness of the thickest part of the yoke 110 is hx1, and the thickness of the thinnest part of the yoke 110 is hx2, which satisfies: 0.05≤hx2 / hx1≤0.95. For example, the value of hx2 / hx1 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. It should be noted that the thickness hx2 at the thinnest part of the yoke 110 is the shortest distance between the inner wall of the groove 111 and the outer wall of the yoke 110. When hx1 remains unchanged, when hx2 / hx1 is less than 0.05, it means that the value of hx2 is too small, and the distance between the inner wall of the groove 111 and the outer wall of the yoke 110 is too close, which easily leads to too low strength at the thinnest part, and risks such as deformation and fracture are prone to occur, the safety and stability of the rotor 100 are reduced, and the quality of the rotor 100 is poor. When hx2 / hx1 is greater than 0.95, it means that the value of hx2 is too large, that is, the depth of the groove 111 in the radial direction of the rotor 100 is too shallow, and it is difficult to increase the volume of the permanent magnet 120. Therefore, by reasonably designing the range of hx2 / hx1, it is possible to effectively increase the volume of the permanent magnet 120 while ensuring the overall strength of the yoke 110, so as to improve the output power of the motor.

[0053] Continue to refer to Figure 2 As shown, in the embodiment of the utility model, along the circumference of the rotor 100, the minimum distance between two adjacent grooves 111 is wx1, and the maximum opening width of the groove 111 is wx2, which satisfies: 0.05≤wx2 / (wx1+wx2)≤0.95. For example, the value of wx2 / (wx1+wx2) can be 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, etc. It should be noted that the spacing of two adjacent grooves 111 is conducive to the protrusion of the permanent magnet 120 along the circumference of the rotor 100, thereby increasing the volume of the permanent magnet 120. In order to maintain the number of grooves 111 unchanged, when wx1 increases, wx2 needs to be reduced, or when wx1 decreases, wx2 needs to be increased. When the value of wx2 / (wx1+wx2) is less than 0.05, that is, the value of wx1 is too large and the value of wx2 is too small, the volume of the permanent magnet 120 that can be accommodated is very small, and it is difficult to play a role in improving the magnetic field strength. When the value of wx2 / (wx1+wx2) is greater than 0.95, that is, the value of wx1 is too small and the value of wx2 is too large, the distance between adjacent grooves 111 is too close, resulting in the structural strength between adjacent grooves 111 being too low, and it is easy to have adverse effects such as deformation and fracture. Therefore, by reasonably designing the size of wx2 / (wx1+wx2), the volume of the permanent magnet 120 can be effectively increased while ensuring the overall structural strength of the yoke 110.

[0054] Reference Figure 2 and Figure 3As shown, in the embodiment of the utility model, along the circumferential direction of the rotor 100, the maximum width of the permanent magnet 120 is wx3, which satisfies: 0.05≤wx2 / wx3≤0.95, for example, the value of wx2 / wx3 can be 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, etc. It should be noted that when adjacent grooves 111 are connected to each other, the connection is easy to form a sharp point, which is not conducive to production and manufacturing, so the grooves 111 are usually arranged at intervals. In order to further increase the volume of the permanent magnet 120, by designing the maximum width wx3 of the permanent magnet 120 to be greater than the maximum opening width wx2 of the groove 111, the two ends of the permanent magnet 120 protrude from the groove 111 along the circumferential direction of the rotor 100, so that the volume of the permanent magnet 120 can be further increased without increasing the outer diameter of the motor to increase the magnetic field strength.

[0055] Reference Figure 2 and Figure 3 As shown, in the embodiment of the utility model, along the radial direction of the rotor 100, the thickness of the thickest part of the yoke 110 is hx1, the thickness of the thinnest part of the yoke 110 is hx2, and the maximum thickness of the permanent magnet 120 is hx3, which satisfies: 0.05≤hx1 / (hx3+hx2)≤0.95. For example, the value of hx1 / (hx3+hx2) can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, etc. When hx1 / (hx3+hx2) is less than 0.05, the overall strength of the yoke 110 is low, and the risk of deformation and fracture is prone to occur. When hx1 / (hx3+hx2) is greater than 0.95, the volume of the permanent magnet 120 is too small, which can play a role in increasing the magnetic field strength. Therefore, by reasonably designing the value of hx1 / (hx3+hx2), it is possible to increase the volume of the permanent magnet 120 while ensuring the overall strength of the yoke 110, thereby increasing the magnetic field strength.

[0056] Reference Figure 2 and Figure 3 As shown, in an embodiment of the utility model, the yoke 110 includes a first section 114 and a second section 115, and the first section 114 and the second section 115 are both provided with a plurality and the number of the first section 114 and the second section 115 is the same. The plurality of first sections 114 and the plurality of second sections 115 are alternately connected in sequence, or in other words, each two adjacent first sections 114 are connected by a second section 115. The first section 114 is provided with a groove 111, and two adjacent permanent magnets 120 are abutted against each other, and a gap 130 is formed between the inner side walls of the two adjacent permanent magnets 120 and the second section 115. By providing the gap 130, the inter-pole leakage magnetic flux of the two adjacent permanent magnets 120 can be effectively reduced, the efficiency and operation stability of the motor can be improved, and the service life of the motor can be extended and the motor performance can be optimized.

[0057] Reference Figure 3 As shown, in an embodiment of the utility model, the width of the gap 130 gradually decreases in the direction close to the axis of rotation. It should be noted that the width of the gap 130 refers to the width of the gap 130 along the circumferential direction of the rotor 100. In order to gradually reduce the width of the gap 130, it can be achieved by providing chamfers, fillets 121, etc. on the side of the permanent magnet 120 facing the second section 115, which can further reduce the inter-pole magnetic leakage of two adjacent permanent magnets 120. Among them, a fillet 121 is provided at at least one end of the permanent magnet 120 along the circumferential direction of the rotor 100, for example, fillets 121 are provided at both ends of the permanent magnet 120, which can reduce the severity of the change in magnetic lines of force and reduce the cogging torque and torque pulsation. The radius of the fillet is R, which satisfies: 0.3mm≤R≤4mm, for example, the value of R is 0.6mm, 0.8mm, 1mm, 1.5mm, 1.8mm, 2mm, 3mm. Refer to Fig.10 As shown, Fig.10 The horizontal axis in represents the radius of the fillet 121, in mm, and the vertical axis represents the cogging torque, and the small squares represent the cogging torque at the corresponding radius of the fillet 121. Fig.10 As can be seen from the figure, as the radius of the fillet 121 increases, the cogging torque first decreases and then increases. Therefore, the cogging torque can be reduced by properly designing the size of the fillet 121.

[0058] Reference Figure 6 As shown, in another embodiment of the utility model, the yoke 110 includes an arc segment 112, and the arc segment 112 is provided with a plurality of arc segments and is arranged around the axis of rotation. The inner wall of the arc segment 112 is recessed to form a groove 111, and the outer wall of the arc segment 112 protrudes outward. The yoke 110 adopts the above scheme, which can also increase the volume of the permanent magnet 120 to improve the magnetic field strength. The magnetic lines of force of the permanent magnet 120 are gathered on the side close to the air gap of the motor, which can improve the air gap magnetic density, and at the same time can reduce the saturation degree of the rotor 100, thereby improving the output power of the motor. At the same time, it is conducive to processing and manufacturing, for example, stretching, stamping and other methods can be adopted, and the production efficiency is higher.

[0059] Reference Figure 7 As shown, in the embodiment of the utility model, the yoke 110 further includes a plurality of connecting segments 113, the number of the connecting segments 113 is the same as the number of the arc segments 112, and the adjacent arc segments 112 are connected by the connecting segments 113, that is, the arc segments 112 and the connecting segments 113 are connected alternately in sequence. By adopting the above scheme, the overall strength of the yoke 110 can be improved, the magnetic circuit can be optimized, and the arc segments 112 can increase the surface area of ​​the yoke 110, thereby improving the heat dissipation performance.

[0060] Reference Figure 7As shown, in the embodiment of the utility model, along the radial direction of the rotor 100, the maximum thickness of the connecting section 113 is hy1, and the maximum thickness of the arc section 112 is hy2, satisfying: hy1 ≥ hy2, for example, hy1 = 1.1*hy2, hy1 = 1.2*hy2, hy1 = 1.3*hy2, hy1 = 1.5*hy2, hy1 = 1.8*hy2, hy1 = 2*hy2, hy1 = 2.5*hy2. It can be understood that the connecting section 113 is mainly used to form a magnetic circuit between two magnetic poles, so it requires a wider width than the arc section 112 to reduce or avoid the blockage of the magnetic circuit and the reduction of magnetic flux. The arc section 112 is mainly used to form the magnetic circuit of a single magnetic pole, and the width requirement is lower than that of the arc section 112. Therefore, the reasonable design of the thickness of the connecting section 113 and the arc section 112 can optimize the magnetic circuit and improve the efficiency of the motor.

[0061] Reference Figure 7 As shown, in the embodiment of the present invention, along the circumference of the rotor 100, the maximum width of the arc segment 112 is wy1, and the maximum width of the connecting segment 113 is wy2, satisfying: wy1≥wy2, for example, wy1=1.1*wy2, wy1=1.2*wy2, wy1=1.3*wy2, wy1=1.5*wy2, wy1=1.8*wy2, wy1=2*wy2, wy1=3*wy2. It can be understood that the arc segment 112 is used to install the permanent magnet 120, so when the maximum width wy1 of the arc segment 112 is greater than or equal to the maximum width wy2 of the connecting segment 113, the volume of the permanent magnet 120 that can be installed by the arc segment 112 is larger, thereby increasing the magnetic flux. Since the connecting section 113 is located between the two arc sections 112, when the maximum width wy2 of the connecting section 113 is greater than the maximum width wy1 of the arc section 112, the magnetic field concentration effect is not obvious, the distance between the magnetic poles increases, the magnetic flux area decreases, and the motor performance decreases. Therefore, by reasonably designing the relationship between the maximum width wy2 of the connecting section 113 and the maximum width wy1 of the arc section 112, the volume of the permanent magnet 120 can be increased, the magnetic flux can be increased, and the magnetic field concentration effect can be improved, the magnetic flux area can be increased, and the efficiency of the motor can be improved.

[0062] Reference Figure 6As shown, in the embodiment of the present invention, the maximum thickness between the maximum inscribed circle of the rotor 100 and the outer side wall of the yoke 110 is hy3, and the minimum thickness between the maximum inscribed circle of the rotor 100 and the outer side wall of the yoke 110 is hy4, satisfying: hy3>hy4. For example, hy3=1.2*hy4, hy3=1.3*hy4, hy3=1.5*hy4, hy3=1.8*hy4, hy3=2*hy4. By designing hy3>hy4, that is, the distances from the outer side wall at different positions of the yoke 110 to the axis of rotation are inconsistent, the surface area of ​​the outer side is increased, the heat dissipation effect of the yoke 110 can be improved, the magnetic field distribution can be optimized, and it is also easy to manufacture and process.

[0063] In another embodiment, referring to Figure 8 and Fig. 9 As shown, the yoke 110 may also only include a plurality of arc segments 112 , and the plurality of arc segments 112 are connected to form the yoke 110 . A suitable solution is selected according to actual conditions.

[0064] The motor of an embodiment of the utility model comprises a stator 200 and a rotor 100 of the above embodiment, the rotor 100 is arranged around the outer side of the stator 200, and the motor can be a permanent magnet motor. The motor of the utility model embodiment adopts the rotor 100 of the above embodiment, and by setting a plurality of grooves 111 on the inner side wall of the yoke 110, a plurality of permanent magnets 120 are installed in the corresponding grooves 111, so that the grooves 111 can play a positioning role, which is convenient for installing the permanent magnets 120 and improving the installation efficiency. Since the grooves 111 are formed by the inner side depression of the yoke 110, when the rotor 100 of the utility model embodiment is applied to the motor, it can match the rotor 100 of the same size and model without increasing the outer dimensions of the motor. The permanent magnet 120 protrudes toward one side of the groove 111, which can increase the volume of the permanent magnet 120 to improve the magnetic field strength; and the magnetic lines of force of the permanent magnet 120 are gathered on the side close to the air gap of the motor, which can improve the air gap magnetic density, reduce the saturation degree of the rotor 100, and thus improve the output power of the motor.

[0065] Reference Figure 5As shown, in an embodiment of the present invention, the stator 200 includes a stator core 210 and a winding 212, the stator core 210 includes a plurality of teeth 213, the plurality of teeth 213 surround the rotation axis and are arranged at intervals, winding slots are formed between adjacent teeth 213, and the winding 212 is wound around the teeth 213 through the winding slots. A tooth top 211 is provided at one end of the tooth 213 facing the rotor 100. Along the circumference of the rotor 100, the maximum width of the tooth top 211 is wx4, and the maximum width of the permanent magnet 120 is wx3, satisfying: 0.7≤wx4 / wx3≤1.3, for example, the value of wx4 / wx3 can be 0.8, 0.9, 1, 1.1, 1.2. When wx4 / wx3 is less than 0.7 or greater than 1.3, it indicates that the difference between the maximum width of the tooth top 211 and the maximum width of the permanent magnet 120 is too large. Since the magnetic flux area is based on the smallest width of the tooth top 211 and the permanent magnet 120, it will lead to a reduction in the magnetic flux area, low magnetic circuit utilization, and increased cogging torque. By setting the value of wx4 / wx3 within the range of 0.7 to 1.3, for example, wx4 / wx3=1, that is, the maximum width of the tooth top 211 is equal to the maximum width of the permanent magnet 120, the magnetic flux area can be maximized and the cogging torque of the motor can be reduced.

[0066] It should be noted that the cogging torque is generated by the interaction between the flux emitting surface and the flux receiving surface. When only focusing on one flux emitting surface and the flux receiving surface, the flux emitting surface and the flux receiving surface interact with each other, resulting in energy changes, and then generating cogging torque. If the flux receiving surface and the flux emitting surface are nearly equal, when the flux emitting surface passes through a complete flux receiving surface, the positive and negative half-cycles of the cogging torque formed are symmetrical, and it is a complete single-tooth cogging torque waveform (0→maximum→0→minimum→0), and the number of cycles of the cogging torque is equal to the number of slots. Finally, the cogging torque waveforms formed by the two relative teeth 213 are equal in size and opposite in direction (the same is true for other relative teeth 213), and they cancel each other out, and the overall cogging torque reaches the minimum. If the flux receiving surface and the flux emitting surface are far apart, when the flux emitting surface passes through a complete flux receiving surface, the single-tooth cogging torque waveform is incomplete, resulting in the inability to completely cancel each other out, and the cogging torques of the teeth 213 of the overall stator core 210 are superimposed on each other, making the cogging torque larger.

[0067] In the embodiment of the utility model, the maximum axial length of the yoke 110 is Lx1, the maximum axial length of the stator 200 is Lx2, and the maximum axial length of the permanent magnet 120 is Lx3, which satisfies: 0<Lx2 / Lx1≤1, 0<Lx1 / Lx3≤1. That is, Lx2 can be equal to Lx1 or Lx2 is less than Lx1, for example, the value of Lx2 / Lx1 can be 0.5, 0.6, 0.7, 0.8, 0.9, etc., and the value of Lx1 / Lx3 can be 0.5, 0.6, 0.7, 0.8, 0.9, etc. Permanent magnet motors usually have an end effect, which refers to the phenomenon that non-uniform magnetic field distribution will be generated at both ends of the motor, making the magnetic resistance of the motor uneven, increasing the magnetic resistance loss, and reducing the efficiency of the motor. When Lx1 is greater than Lx2, that is, the yoke 110 protrudes from the stator 200 along the axial direction of the motor, and Lx3 is greater than Lx1, that is, the permanent magnet 120 protrudes from the yoke 110 along the axial direction, the uniformity of the magnetic field distribution can be improved, thereby improving the uniformity of the magnetic resistance, reducing the magnetic resistance loss, and improving the efficiency of the motor.

[0068] In an embodiment of the utility model, the number of poles of the motor is Np, the number of poles of the motor is the same as the number of grooves 111, and satisfies: 2≤Np≤30, the number of winding grooves is Ns, and satisfies: 3≤Ns≤30, and satisfies 1≤Ns±Np≤6. For example, Np can be 8, 10, 12, 14, and Ns can be 9, 12. Among them, by reasonably designing the values ​​of Ns and Np, the torque, speed and efficiency of the motor can be optimized. For example, a larger number of poles generally means a higher speed and torque, but may increase the inertia during rotation. At the same time, an increase in the number of winding grooves can improve the output torque and stability of the motor, but may increase resistance losses. Therefore, it is necessary to balance these factors according to the specific application scenario.

[0069] A household appliance of an embodiment of the utility model includes the motor of the above embodiment, and the household appliance can be an air conditioner, a refrigerator, an electric fan, a range hood, etc. The household appliance of the embodiment of the utility model adopts the motor of the above embodiment, and a plurality of grooves 111 are provided on the inner side wall of the yoke 110, and a plurality of permanent magnets 120 are installed in the corresponding grooves 111, so that the grooves 111 can play a positioning role, which is convenient for installing the permanent magnets 120 and improving the installation efficiency. Since the grooves 111 are formed by the inner side depression of the yoke 110, when the rotor 100 of the utility model embodiment is applied to the motor, it can match the rotor 100 of the same size and model without increasing the external dimensions of the motor. The permanent magnet 120 protrudes toward one side of the groove 111, which can increase the volume of the permanent magnet 120 to increase the magnetic field strength; and the magnetic lines of force of the permanent magnet 120 are gathered on the side close to the air gap of the motor, which can improve the air gap magnetic density, reduce the saturation degree of the rotor 100, and thus improve the output power of the motor.

[0070] Since the household appliance adopts all the technical solutions of the motor of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described in detail here.

[0071] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A rotor, rotating about an axis of rotation, characterized in that include: A ring-shaped yoke, wherein the inner side wall of the yoke is provided with a plurality of grooves, and the plurality of grooves are arranged around the rotation axis; A plurality of permanent magnets, the number of the permanent magnets and the number of the grooves are the same, the plurality of permanent magnets are respectively installed in the corresponding grooves, the permanent magnets protrude toward one side of the groove, and at least part of the structure of the permanent magnets abuts against the inner wall of the groove.

2. The rotor according to claim 1, characterized in that: The side of the permanent magnet facing the groove is a first convex arc surface, and / or the side of the permanent magnet facing the rotation axis is concave to form a second arc surface.

3. The rotor according to claim 1, characterized in that: Along the radial direction of the rotor, the thickness of the thickest part of the yoke is hx1, and the thickness of the thinnest part of the yoke is hx2, satisfying: 0.05≤hx2 / hx1≤0.

95.

4. The rotor according to claim 1, characterized in that: Along the circumferential direction of the rotor, the minimum distance between two adjacent grooves is wx1, and the maximum opening width of the groove is wx2, satisfying: 0.05≤wx2 / (wx1+wx2)≤0.

95.

5. The rotor according to claim 1, characterized in that: Along the circumferential direction of the rotor, the maximum width of the permanent magnet is wx3, and the maximum opening width of the groove is wx2, satisfying: 0.05≤wx2 / wx3≤0.

95.

6. The rotor according to claim 1, characterized in that: Along the radial direction of the rotor, the thickness of the thickest part of the yoke is hx1, the thickness of the thinnest part of the yoke is hx2, and the maximum thickness of the permanent magnet is hx3, satisfying: 0.05≤hx1 / (hx3+hx2)≤0.

95.

7. The rotor according to claim 1, characterized in that: The yoke includes multiple first sections and multiple second sections, two adjacent first sections are connected by one second section, the groove is located in the first section, and the parts of two adjacent permanent magnets protruding from the groove along the circumference of the rotor are abutted against each other, and a gap is formed between the inner side wall of the second section.

8. The rotor according to claim 7, characterized in that: The width of the gap gradually decreases in a direction approaching the rotation axis.

9. The rotor according to claim 1 or 8, characterized in that: At least one end of the permanent magnet along the circumference of the rotor is provided with a rounded corner, the radius of the rounded corner is R, and satisfies: 0.3mm≤R≤4mm.

10. The rotor according to claim 1, characterized in that: The yoke comprises a plurality of arc segments arranged around the rotation axis, the inner side walls of the arc segments are recessed to form the grooves, and the outer side walls of the arc segments protrude outwards.

11. The rotor according to claim 10, characterized in that: The yoke also includes a plurality of connecting segments, and adjacent arc segments are connected by the connecting segments.

12. The rotor according to claim 11, characterized in that: Along the radial direction of the rotor, the maximum thickness of the connecting segment is hy1, and the maximum thickness of the arc segment is hy2, satisfying: hy1≥hy2.

13. The rotor according to claim 11, characterized in that: Along the circumferential direction of the rotor, the maximum width of the arc segment is wy1, and the maximum width of the connecting segment is wy2, satisfying: wy1≥wy2.

14. The rotor according to claim 10, characterized in that: The maximum thickness between the maximum inscribed circle of the rotor and the outer side wall of the yoke is hy3, and the minimum thickness between the maximum inscribed circle of the rotor and the outer side wall of the yoke is hy4, satisfying: hy3>hy4.

15. The motor is characterized by: The invention comprises a stator and the rotor according to any one of claims 1 to 14, wherein the rotor is arranged around the outer side of the stator.

16. The motor according to claim 15, characterized in that: The stator includes a stator core, and the stator core includes tooth tops. Along the circumference of the rotor, the maximum width of the tooth tops is wx4, and the maximum width of the permanent magnet is wx3, satisfying: 0.7≤wx4 / wx3≤1.

3.

17. The motor according to claim 15, characterized in that: The maximum axial length of the yoke is Lx1, the maximum axial length of the stator is Lx2, and the maximum axial length of the permanent magnet is Lx3, satisfying: 0<Lx2 / Lx1≤1, 0<Lx1 / Lx3≤1.

18. A household appliance, characterized in that: A motor comprising the motor described in any one of claims 15 to 17.

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