Rotor assembly, motor and household appliance

Abstract

The utility model discloses a rotor assembly, a motor and a household electrical appliance, and relates to the technical field of motors, the rotor assembly comprises a rotor iron core and a plurality of permanent magnets, the rotor assembly comprises the rotor iron core and the plurality of permanent magnets, the rotor iron core comprises a plurality of iron core units, and mounting grooves for mounting the permanent magnets are formed between the adjacent iron core units. Each permanent magnet comprises a first magnetic part and a second magnetic part which are sequentially connected from outside to inside in the radial direction of the rotor assembly, and the width of one end, away from the first magnetic part, of the second magnetic part is smaller than that of one end, close to the second magnetic part, of the first magnetic part. Each iron core unit comprises a fan-shaped part and a magnetic bridge connected with the fan-shaped part, the side walls of the fan-shaped parts on the two sides of the mounting grooves abut against the first magnetic parts, and the side walls of the magnetic bridges on the two sides of the mounting grooves abut against the second magnetic parts. Therefore, compared with a rotor assembly in the prior art, the permanent magnet is additionally provided with the second magnetic part, so that the size of the permanent magnet is increased, the magnetic flux of the rotor assembly is increased, and the performance of the motor is improved.

Description

Technical Field

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

[0002] In the related art, permanent magnet motors can be used in household appliances such as air conditioners, refrigerators, washing machines, vacuum cleaners, etc. to drive the corresponding parts to rotate. The permanent magnet motor includes a rotor assembly, in which a plurality of permanent magnets are arranged. The magnetic field generated by the permanent magnets interacts with the magnetic field generated by the windings of the stator assembly to rotate the rotor assembly. The magnetic flux of the permanent magnet will affect the output performance of the permanent magnet motor, such as torque, speed and efficiency. In order to increase the magnetic flux, more permanent magnets are usually arranged in the motor, but this will increase the size of the motor, which is not suitable for the requirements of miniaturization and high 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 assembly, which can increase the magnetic flux of the permanent magnet without changing the outer contour size, so as to improve the performance of the motor.

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

[0005] According to the rotor assembly of the first aspect of the present invention, the rotor assembly rotates around a rotation axis, and the rotor assembly includes a rotor core and a plurality of permanent magnets, wherein the rotor core includes a plurality of core units arranged around the rotation axis, and mounting grooves are formed between adjacent core units, and the plurality of permanent magnets are respectively mounted in corresponding mounting grooves;

[0006] The permanent magnet comprises a first magnetic portion and a second magnetic portion connected in sequence from outside to inside along the radial direction of the rotor assembly, wherein the width of the second magnetic portion away from an end of the first magnetic portion is smaller than the width of the first magnetic portion close to an end of the second magnetic portion;

[0007] The core unit includes a fan-shaped portion and a magnetic bridge connected to the fan-shaped portion at one end close to the rotation axis. Along the circumference of the rotor assembly, the side walls of the fan-shaped portion on both sides of the mounting slot abut against the first magnetic portion, and the side walls of the magnetic bridge on both sides of the mounting slot abut against the second magnetic portion.

[0008] The rotor assembly according to the embodiment of the utility model has at least the following beneficial effects:

[0009] The rotor assembly includes a rotor core and a plurality of permanent magnets, and the rotor core includes a plurality of core units, and a mounting groove for mounting the permanent magnet is formed between adjacent core units. The permanent magnet includes a first magnetic portion and a second magnetic portion connected in sequence from outside to inside along the radial direction of the rotor assembly, and the width of the second magnetic portion away from the end of the first magnetic portion is smaller than the width of the first magnetic portion close to the end of the second magnetic portion. The core unit includes a fan-shaped portion and a magnetic bridge connecting the fan-shaped portions, the side walls of the fan-shaped portions on both sides of the mounting groove abut against the first magnetic portion, and the side walls of the magnetic bridge on both sides of the mounting groove abut against the second magnetic portion. Therefore, compared with the rotor assembly in the related art, the permanent magnet of this embodiment is additionally provided with a second magnetic portion, thereby increasing the volume of the permanent magnet, thereby increasing the magnetic flux of the rotor assembly, and improving the performance of the motor.

[0010] According to some embodiments of the present invention, the widths of the first magnetic parts are equal, and the widths of the second magnetic parts gradually decrease along a direction approaching the rotation axis.

[0011] According to some embodiments of the present invention, the width of the first magnetic portion is W1, and the minimum width of the second magnetic portion is W2, satisfying: W2<W1≤3*W2.

[0012] According to some embodiments of the present invention, the minimum width of the second magnetic portion is W2, satisfying: W2 ≥ 1 mm.

[0013] According to some embodiments of the present invention, the rotor core includes a plurality of rotor punchings stacked along the direction of the rotation axis, the maximum thickness of the rotor punchings is t, and the minimum width of the magnetic bridge is W. b , satisfying: W b ≥1.2*t.

[0014] According to some embodiments of the present invention, along the radial direction, the length of the first magnetic portion is L1, and the length of the second magnetic portion is L2, satisfying: 0.05≤L2 / L1≤0.35.

[0015] According to some embodiments of the utility model, the magnetic bridge includes a first connecting portion and a first protrusion, the first connecting portion is connected to the fan-shaped portion, and the first protrusion is connected to the side of the first connecting portion facing the mounting groove; along the circumferential direction, one of the side walls on the two opposite sides of the second magnetic portion abuts against the first connecting portion; along the radial direction, the end wall of the second magnetic portion away from one end of the first magnetic portion abuts against the first protrusion.

[0016] According to some embodiments of the utility model, the core unit includes a plurality of rotor punchings stacked along the direction of the rotation axis, the maximum thickness of the rotor punchings is t, and along the radial direction, the maximum thickness of the first protrusion is K1, satisfying: t≤K1≤3t.

[0017] According to some embodiments of the utility model, the core unit also includes a second protrusion, which is connected to the side of the fan-shaped portion facing the mounting groove, and the end wall of the first magnetic portion away from one end of the second magnetic portion abuts against the second protrusion, and along the radial direction, the maximum thickness of the second protrusion is K2. The core unit includes a plurality of rotor punchings stacked along the direction of the rotation axis, and the maximum thickness of the rotor punchings is t, satisfying: t≤K2≤3t.

[0018] According to some embodiments of the present invention, the magnetic bridge includes a first bridge segment and a second bridge segment connected in sequence along the radial direction of the rotor assembly, the second bridge segment is closer to the rotation axis than the first bridge segment, the width of the first bridge segment gradually decreases in the direction approaching the rotation axis, and the minimum width of the first bridge segment is greater than or equal to the maximum width of the second bridge segment.

[0019] According to some embodiments of the present invention, the cross-section of the second magnetic portion is square or trapezoidal; or the two side walls of the second magnetic portion along the circumferential direction are concave in directions approaching each other or convex in directions away from each other.

[0020] The motor according to the second embodiment of the utility model includes the rotor assembly described in the above embodiment.

[0021] The motor according to the embodiment of the utility model has at least the following beneficial effects:

[0022] The rotor assembly of the first aspect embodiment is adopted. The rotor assembly is provided with a rotor core and a plurality of permanent magnets. The rotor core includes a plurality of core units, and a mounting groove for mounting the permanent magnet is formed between adjacent core units. The permanent magnet includes a first magnetic portion and a second magnetic portion connected in sequence from the outside to the inside along the radial direction of the rotor assembly, and the width of the second magnetic portion away from the end of the first magnetic portion is smaller than the width of the first magnetic portion close to the end of the second magnetic portion. The core unit includes a fan-shaped portion and a magnetic bridge connecting the fan-shaped portions, the side walls of the fan-shaped portions on both sides of the mounting groove abut against the first magnetic portion, and the side walls of the magnetic bridge on both sides of the mounting groove abut against the second magnetic portion. Therefore, compared with the rotor assembly in the related art, the permanent magnet of this embodiment is provided with a second magnetic portion, thereby increasing the volume of the permanent magnet, thereby increasing the magnetic flux of the rotor assembly, and improving the performance of the motor.

[0023] The household appliance according to the embodiment of the third aspect of the utility model comprises the motor described in the above embodiment.

[0024] The household appliance according to the embodiment of the utility model has at least the following beneficial effects:

[0025] The motor adopts the second aspect of the embodiment. The motor is provided with a rotor core and a plurality of permanent magnets. The rotor core includes a plurality of core units, and a mounting groove for mounting the permanent magnet is formed between adjacent core units. The permanent magnet includes a first magnetic portion and a second magnetic portion connected in sequence from the outside to the inside along the radial direction of the rotor assembly, and the width of the second magnetic portion away from the end of the first magnetic portion is smaller than the width of the first magnetic portion close to the end of the second magnetic portion. The core unit includes a fan-shaped portion and a magnetic bridge connecting the fan-shaped portions, the side walls of the fan-shaped portions on both sides of the mounting groove abut against the first magnetic portion, and the side walls of the magnetic bridge on both sides of the mounting groove abut against the second magnetic portion. Therefore, relative to the rotor assembly in the related art, the permanent magnet of this embodiment is provided with a second magnetic portion, thereby increasing the volume of the permanent magnet, thereby increasing the magnetic flux of the rotor assembly, and improving the performance of the motor.

[0026] 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

[0027] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0028] Figure 1 This is a schematic diagram of the structure of the stator assembly and the rotor assembly in one embodiment of the utility model;

[0029] Figure 2 This is a schematic structural diagram of a rotor assembly according to an embodiment of the utility model;

[0030] Figure 3 An exploded view of a rotor assembly according to an embodiment of the utility model;

[0031] Figure 4 This is a schematic structural diagram of a rotor punching sheet according to an embodiment of the utility model;

[0032] Figure 5 A top view of a rotor assembly according to an embodiment of the present utility model;

[0033] Figure 6 A partial structural schematic diagram of a rotor assembly according to an embodiment of the utility model;

[0034] Figure 7 for Figure 6 The enlarged view of point A in the middle;

[0035] Figure 8 A side view of a rotor punching sheet according to an embodiment of the utility model;

[0036] Fig. 9 A top view of a rotor assembly according to another embodiment of the present invention;

[0037] Fig.10 A top view of a rotor assembly according to another embodiment of the present invention;

[0038] Fig.11 A top view of a rotor assembly according to another embodiment of the present invention;

[0039] Fig.12 It is a partial structural schematic diagram of a rotor assembly of another embodiment of the utility model;

[0040] Fig.13 A graph showing the relationship between the motor torque and the length of the second magnetic part according to an embodiment of the utility model;

[0041] Fig.14 This is a relationship diagram between the motor efficiency and the length of the second magnetic part according to an embodiment of the utility model.

[0042] Figure Number:

[0043] Rotor assembly 1000;

[0044] Rotor core 100; core unit 110; mounting groove 111; sector 112; magnetic bridge 113; first side wall 1131; second side wall 1132; first connecting portion 1133; first convex portion 1134; first bridge section 1135; second bridge section 1136; second convex portion 114; rotor punching 120;

[0045] Permanent magnet 200; first magnetic part 210; second magnetic part 220; third magnetic part 230;

[0046] Rotating shaft 300;

[0047] Stator assembly 2000; stator core 2100; winding 2200. DETAILED DESCRIPTION

[0048] 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.

[0049] In the description of the present invention, it should be understood that the descriptions involving orientation, such as the orientation or positional relationship indicated as up, down, etc., are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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.

[0050] In the description of the present utility model, "a plurality" means more than two. If there is a description of "first" or "second", it is only 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.

[0051] 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.

[0052] Motors are important components in household appliances, for example, motors used to drive the fan of air conditioners, motor components inside compressors, motors for washing machines, motors for dishwashers, etc. With the development of the household appliance industry, miniaturization and high power have become the development direction of the new generation of motors.

[0053] The motor generally includes a stator assembly and a rotor assembly, wherein the rotor assembly rotates around the rotation axis of the motor, and the stator assembly is arranged around the rotation axis. Under the action of the electromagnetic field, the rotor assembly can rotate relative to the stator assembly, thereby driving the load connected to the output end of the motor to rotate. It can be understood that in one embodiment, the stator assembly is configured to be arranged around the outside of the rotor assembly, which is an inner rotor motor; in another embodiment, the stator assembly is configured to be arranged around the inside of the rotor assembly, which is an outer rotor motor.

[0054] In order to facilitate understanding of the solutions of the embodiments of the present utility model, the following description is given by taking an inner rotor motor as an example.

[0055] Reference Figure 1As shown, the motor of the embodiment of the utility model includes a stator assembly 2000 and a rotor assembly 1000, the rotor assembly 1000 includes a rotating shaft 300, the central axis of the rotating shaft 300 coincides with the rotation axis of the motor, and the stator assembly 2000 is arranged around the outer side of the rotor assembly 1000. In order to improve the stability and reliability of the motor, the rotor assembly 1000 and the stator assembly 2000 are generally respectively subjected to plastic coating treatment before being assembled. The rotor assembly 1000 includes a rotor core 100, a plurality of permanent magnets 200 and a rotating shaft 300, and the rotor core 100 can be arranged around the rotation axis of the rotating shaft 300. The rotor core 100 is provided with a plurality of mounting grooves 111, and the plurality of permanent magnets 200 are mounted in the corresponding mounting grooves 111 one by one, and the rotating shaft 300 is mounted inside the rotor core 100. The assembled rotor core 100, the plurality of permanent magnets 200 and the rotating shaft 300 are connected by an integral injection molding process, which is the plastic coating treatment of the rotor assembly 1000. The stator assembly 2000 includes a stator core 2100, an insulating frame and a winding 2200, and the insulating frame is not shown in the figure. The assembled stator core 2100, the insulating frame and the winding 2200 are connected by an integrated injection molding process, which is the overmolding treatment of the stator assembly 2000. It should be noted that the overmolding treatment of the stator assembly 2000 generally forms a partial housing of the motor at the same time, so as to facilitate rapid assembly with the rotor assembly 1000. After the overmolding treatment, the rotor assembly 1000 and the stator assembly 2000 can both obtain a more stable structure, so that the internal components are not easily separated, and the connection stability between the components is improved.

[0056] In order to make the permanent magnet 200 generate a larger magnetic flux, refer to Figure 2 and Figure 3 As shown, in an embodiment of the present invention, the rotor assembly 1000 includes a rotor core 100 and a plurality of permanent magnets 200. The rotor core 100 includes a plurality of core units 110 arranged around the rotation axis of the rotating shaft 300. An installation groove 111 is formed between adjacent core units 110, and the plurality of permanent magnets 200 are correspondingly installed in the installation groove 111. The permanent magnet 200 includes a first magnetic portion 210 and a second magnetic portion 220. The first magnetic portion 210 and the second magnetic portion 220 are sequentially connected from outside to inside along the radial direction of the rotor assembly 1000, that is, the first magnetic portion 210 is located on the outside of the second magnetic portion 220, and the second magnetic portion 220 is closer to the rotating shaft 300 than the first magnetic portion 210. Along the circumferential direction of the rotor assembly 1000, the width of the second magnetic portion 220 away from the first magnetic portion 210 is smaller than the width of the first magnetic portion 210 close to the second magnetic portion 220. Referring to Figure 4 and Figure 5As shown, the core unit 110 includes a sector 112 and a magnetic bridge 113, and the magnetic bridge 113 is connected to one end of the sector 112 close to the rotation axis. Along the circumference of the rotor assembly 1000, the side walls of the sector 112 on both sides of the mounting slot 111 abut against the first magnetic portion 210, and the side walls of the magnetic bridge 113 on both sides of the mounting slot 111 abut against the second magnetic portion 220, thereby limiting the position of the permanent magnet 200.

[0057] It is understandable that, by adopting the above solution, the rotor assembly 1000 can utilize the space defined between two adjacent magnetic bridges 113, so that the permanent magnet 200 is provided with a second magnetic portion 220 on the basis of the original first magnetic portion 210, thereby increasing the overall volume of the permanent magnet 200. Therefore, compared with the rotor assembly 1000 in the related art, the permanent magnet 200 of this embodiment is provided with a second magnetic portion 220, thereby increasing the volume of the permanent magnet 200, thereby increasing the magnetic flux of the rotor assembly 1000, and improving the performance of the motor.

[0058] Reference Figure 6 and Figure 7 As shown, in an embodiment of the utility model, along the circumference of the rotor assembly 1000, the width of the first magnetic portion 210 is W1, and the minimum width of the second magnetic portion 220 is W2, satisfying: W2<W1≤3*W2. Wherein, the above formula is equivalent to 1<W1 / W2≤3, for example, W1 / W2 can be 1.1, 1.2, 1.3, 2 or 3, etc. It should be noted that since the multiple fan-shaped portions 112 are radially distributed, the closer the mounting groove 111 is to the rotation axis position of the shaft 300, the smaller its volume. Therefore, W2 is required to be less than W1, so that the permanent magnet 200 can be smoothly installed in the mounting groove 111. When W2 is greater than or equal to W1, it is easy to cause the permanent magnet 200 to fail to be installed smoothly, or cause the magnetic bridge 113 to become thinner, and the strength decreases, which can easily lead to breakage. At the same time, in order to save costs, there are usually not many structural changes to the existing motor models, so the size of the first magnetic part 210 is usually unchanged, while the newly added second magnetic part 220 needs to be adaptively designed. When W1 / W2 is greater than 3, that is, the minimum width of the second magnetic part 220 is too small, the increase in magnetic flux is not obvious, the difficulty in production and manufacturing is greater, and the yield rate is low. Therefore, by reasonably designing the size of W1 / W2, it is possible to ensure smooth installation while also making the magnetic bridge 113 have appropriate strength. At the same time, the overall structure of the motor does not need to be greatly improved to increase the magnetic flux.

[0059] Reference Figure 7As shown, in the embodiment of the utility model, along the circumference of the rotor assembly 1000, the width of the first magnetic part 210 is equal, and the width of the second magnetic part 220 gradually decreases along the direction close to the rotation axis of the shaft 300, that is, the cross section of the second magnetic part 220 is trapezoidal. Adopting this scheme, the difficulty of manufacturing the permanent magnet 200 is reduced, and the manufacturability is good. Compared with the scheme in which the cross section of the second magnetic part 220 is in other shapes, such as square, irregular shape, etc., the volume of the second magnetic part 220 can be made larger, thereby generating a larger magnetic flux.

[0060] The cross section of the second magnetic portion 220 may be in other shapes besides a trapezoidal shape. Fig. 9 As shown, the cross section of the second magnetic portion 220 is square (e.g., square or rectangular), that is, the width of the second magnetic portion 220 remains unchanged, and the magnetic bridge 113 is tapered. Therefore, the width of the magnetic bridge 113 in the circumferential direction of the rotor assembly 1000 can be made wider, which can improve the overall structural strength and reliability of the magnetic bridge 113 and effectively reduce the occurrence of fracture of the magnetic bridge 113 due to fatigue.

[0061] Reference Fig.10 As shown, in another embodiment of the present invention, the two side walls of the second magnetic portion 220 facing the two adjacent magnetic bridges 113 are concave in the direction of approaching each other, such as an inwardly concave arc surface or an inwardly concave multi-segment surface, so that the magnetic bridge 113 protrudes toward one side of the second magnetic portion 220, so that the magnetic bridge 113 is roughly elliptical. The width of the magnetic bridge 113 can also be made wider, although the structural strength is slightly worse than Fig. 9 The solution shown, however Fig.10 The solution shown can enable the permanent magnet 210 to generate a larger magnetic flux.

[0062] Reference Fig.11 As shown, in another embodiment of the utility model, the second magnetic portion 220 protrudes in directions away from each other toward the two side walls of the two adjacent magnetic bridges 113, such as an outward convex arc surface or an outward convex multi-segment surface, so that the width of the end of the magnetic bridge 113 close to the rotating shaft 300 is larger, and the width of the end away from the rotating shaft 300 is smaller. Since this solution will reduce the width of the magnetic bridge 113, in order to ensure the strength of the magnetic bridge 113, it is necessary to shorten the radial length of the magnetic bridge 113 to reduce the risk of the magnetic bridge 113 breaking during the operation of the motor, so that a rotating shaft 300 with a larger shaft diameter can be used, or more plastic packaging materials can be filled in the middle of the rotor assembly 1000 to improve the overall reliability of the rotor assembly 1000.

[0063] Reference Fig.12As shown, in another embodiment of the utility model, the permanent magnet 200 may further include a third magnetic portion 230, the third magnetic portion 230 is connected to one end of the second magnetic portion 220 away from the first magnetic portion 210, and the inclination angle of the inclined surface of the third magnetic portion 230 toward the magnetic bridge 113 is greater than the inclination angle of the inclined surface of the second magnetic portion 220 toward the magnetic bridge 113. The inclination angle can be based on the side of the first magnetic portion 210 toward any adjacent sector 112 as a reference, that is, the angle between the inclined surface of the third magnetic portion 230 toward the magnetic bridge 113 and the side of the first magnetic portion 210 is α, and α is greater than the angle β between the inclined surface of the second magnetic portion 220 toward the magnetic bridge 113 and the side of the first magnetic portion 210.

[0064] Since the magnetic bridge 113 needs to abut against the second magnetic portion 220 and the third magnetic portion 230, the magnetic bridge 113 includes a first bridge segment 1135 and a second bridge segment 1136 which are sequentially connected along the radial direction of the rotor assembly 1000, and the second bridge segment 1136 is closer to the rotation axis than the first bridge segment 1135. Along the circumference of the rotor assembly 1000, the width of the first bridge segment 1135 gradually decreases in the direction close to the rotation axis, and the minimum width of the first bridge segment 1135 is greater than or equal to the maximum width of the second bridge segment 1136. The above scheme can improve the strength of the connection between the magnetic bridge 113 and the fan-shaped portion 112, and effectively reduce the risk of the magnetic bridge 113 breaking. Therefore, compared with Figure 5 The solution in the embodiment has a better strength of the magnetic bridge 113 than Fig. 9 , Fig.10 and Fig.11 Therefore, the shape of the second magnetic part 220 and the shape of the magnetic bridge 113 are selected appropriately according to the actual situation.

[0065] Reference Figure 6 As shown, in the embodiment of the utility model, the minimum width W2 of the second magnetic part 220 satisfies: W2 ≥ 1mm. It is understandable that when W2 is less than 1mm, that is, the minimum width of the second magnetic part 220 is too small, it is difficult to manufacture and it is easy to reduce the end strength of the second magnetic part 220. During the production and transportation stage, it is easy to break due to collision, and transportation is difficult. For this reason, a reasonable design of the size of W2 can ensure that the second magnetic part 220 has a certain strength while ensuring manufacturability, thereby reducing the risk of breakage.

[0066] Reference Figure 3 and Figure 4 As shown, in the embodiment of the present invention, the rotor core 100 includes a plurality of rotor punchings 120, and the plurality of rotor punchings 120 are stacked along the direction of the rotation axis. Figure 7 and Figure 8As shown, the maximum thickness of the rotor sheet 120 is t. Along the circumferential direction of the rotor assembly 1000, the two opposite sides of the magnetic bridge 113 are provided with a first side wall 1131 and a second side wall 1132. The minimum distance between the first side wall 1131 and the second side wall 1132 is W. b , satisfying: W b ≥1.2*t.W b It can be understood as the minimum width of the magnetic bridge 113. Since the thickness of the rotor punching 120 is usually determined, generally less than 1 mm. In order to adapt to the shape of the second magnetic part 220, the magnetic bridge 113 needs to be adaptively modified. b When it is less than 1.2t, that is, the distance between the first side wall 1131 and the second side wall 1132 is too short, it is easy to reduce the strength of the magnetic bridge 113, and it is easy to deform, break, and other adverse effects. b and t, so that the strength of the magnetic bridge 113 is guaranteed and the risk of deformation and breakage of the magnetic bridge 113 is effectively reduced.

[0067] Reference Figure 6 As shown, in the embodiment of the present invention, along the radial direction of the rotor assembly 1000, the length of the first magnetic part 210 is L1, and the length of the second magnetic part 220 is L2, which satisfies: 0.05≤L2 / L1≤0.35, for example, L2 / L1 can be 0.15, 0.2, 0.25, 0.3, etc. It should be noted that, under the premise that the length of the first magnetic part 210 remains unchanged, when L2 / L1 is greater than 0.35, it indicates that the length of the second magnetic part 220 is too long. Fig.13 As shown, Fig.13 The horizontal axis in the graph represents the length of the first magnetic part 210 and the second magnetic part 220, and the vertical axis represents the torque of the motor. As can be seen from the figure, with the increase of L2, the torque of the motor is also increasing under the same input current. Fig.14 As shown, Fig.14 The horizontal axis in represents the length of the first magnetic part 210 and the second magnetic part 220, and the vertical axis represents the efficiency of the motor. Fig.14It can be seen that with the increase of L2, the efficiency of the motor first increases and then decreases. The reason for the increase in efficiency is that the volume of the second magnetic part 220 increases, and the magnetic flux also increases; the reason for the subsequent decrease in efficiency is that with the increase of L2, the magnetic field that the magnetic bridge 113 can pass through gradually saturates. After the magnetic field through which the magnetic bridge 113 passes is saturated, even if the length of the second magnetic part 220 increases, the magnetic flux will not increase further, and the iron loss of the motor will increase accordingly, so that the efficiency of the motor will increase first and then decrease. Therefore, the length of L2 is not the longer the better. When L2 / L1 is less than 0.05, that is, the length of the second magnetic part 220 is too short, the increase in magnetic flux is not obvious. Therefore, by reasonably designing the size of L2 / L1, it is possible to ensure that the efficiency of the motor is steadily improved, thereby avoiding the occurrence of negative improvement.

[0068] Reference Figure 6 As shown, in the embodiment of the utility model, the magnetic bridge 113 includes a first connection portion 1133 and a first convex portion 1134, the first connection portion 1133 is connected to the sector portion 112, and the first convex portion 1134 is connected to the side of the first connection portion 1133 facing the mounting groove 111; along the circumferential direction of the rotor assembly 1000, one of the two opposite sides of the second magnetic portion 220 abuts against the first connection portion 1133; along the radial direction of the rotor assembly 1000, the end wall of the second magnetic portion 220 away from one end of the first magnetic portion 210 abuts against the first convex portion 1134. By using the first convex portion 1134 and the second convex portion 114 to limit the position of the permanent magnet 200, it is possible to facilitate the subsequent plastic sealing and improve the assembly efficiency.

[0069] Reference Figure 7 As shown, in the embodiment of the utility model, along the radial direction of the rotor assembly 1000, the maximum thickness of the first protrusion 1134 is K1, satisfying: t≤K1≤3t, t is the thickness of the rotor punching 120 in the axial direction. It can be understood that since the thickness of the rotor punching 120 is usually determined, it is usually within 1 mm. When K1 is less than t, that is, the thickness of the first protrusion 1134 is too small, it is difficult to produce and manufacture, and it is easy to deform and bend, and it is difficult to accurately limit the position of the permanent magnet 200. When K1 is greater than 3t, it is easy to cause magnetic leakage. Therefore, by designing t≤K1≤3t, the first protrusion 1134 has a certain structural strength and is easy to produce.

[0070] Reference Figure 6As shown, in the embodiment of the utility model, along the radial direction of the rotor assembly 1000, the maximum thickness of the second protrusion 114 is K2, which satisfies: t≤K2≤3t, where t is the thickness of the rotor punching 120 in the axial direction. When K2 is less than t, that is, the thickness of the second protrusion 114 is too small, it is difficult to manufacture, and it is easy to deform and bend, and it is difficult to accurately limit the position of the permanent magnet 200. When K2 is greater than 3t, it is easy to cause magnetic leakage. Therefore, by designing t≤K2≤3t, the second protrusion 114 has a certain structural strength and is easy to manufacture.

[0071] The utility model discloses a motor in an embodiment, which is a permanent magnet motor, and includes a rotor assembly 1000 in the above embodiment. The rotor assembly 1000 in the above embodiment is adopted, and the rotor assembly 1000 includes a rotor core 100 and a plurality of permanent magnets 200, and the rotor core 100 includes a plurality of core units 110, and mounting grooves 111 for mounting the permanent magnets 200 are formed between adjacent core units 110. The permanent magnet 200 includes a first magnetic portion 210 and a second magnetic portion 220 connected in sequence from the outside to the inside along the radial direction of the rotor assembly 1000, and the width of the second magnetic portion 220 at the end away from the first magnetic portion 210 is smaller than the width of the first magnetic portion 210 at the end close to the second magnetic portion 220. The core unit 110 includes a sector 112 and a magnetic bridge 113 connecting the sector 112, the side walls of the sector 112 on both sides of the mounting slot 111 abut against the first magnetic portion 210, and the side walls of the magnetic bridge 113 on both sides of the mounting slot 111 abut against the second magnetic portion 220. Therefore, the rotor assembly 1000 can utilize the space defined between two adjacent magnetic bridges 113, so that the permanent magnet 200 is added with a second magnetic portion 220 on the basis of the original first magnetic portion 210, thereby increasing the volume of the permanent magnet 200. Since the space that was not originally used by the rotor assembly 1000 is utilized, the magnetic flux of the permanent magnet 200 can be increased while ensuring that the volume of the rotor assembly 1000 does not change much, so as to improve the output performance of the motor.

[0072] Since the motor of the embodiment of the utility model adopts all the technical solutions of the rotor assembly 1000 of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described in detail here.

[0073] A household appliance of an embodiment of the utility model comprises the motor of the above embodiment, and the household appliance may be an air conditioner, a washing machine, a dishwasher, a refrigerator, etc. The motor of the above embodiment is adopted, and a rotor assembly 1000 is provided to include a rotor core 100 and a plurality of permanent magnets 200, and the rotor core 100 includes a plurality of core units 110, and mounting grooves 111 for mounting the permanent magnets 200 are formed between adjacent core units 110. The permanent magnet 200 comprises a first magnetic portion 210 and a second magnetic portion 220 connected in sequence from the outside to the inside along the radial direction of the rotor assembly 1000, and the width of the second magnetic portion 220 at the end away from the first magnetic portion 210 is smaller than the width of the first magnetic portion 210 at the end close to the second magnetic portion 220. The core unit 110 includes a sector 112 and a magnetic bridge 113 connecting the sector 112, the side walls of the sector 112 on both sides of the mounting slot 111 abut against the first magnetic portion 210, and the side walls of the magnetic bridge 113 on both sides of the mounting slot 111 abut against the second magnetic portion 220. Therefore, the rotor assembly 1000 can utilize the space defined between two adjacent magnetic bridges 113, so that the permanent magnet 200 is added with a second magnetic portion 220 on the basis of the original first magnetic portion 210, thereby increasing the volume of the permanent magnet 200. Since the space that was not originally used by the rotor assembly 1000 is utilized, the magnetic flux of the permanent magnet 200 can be increased while ensuring that the volume of the rotor assembly 1000 does not change much, so as to improve the output performance of the motor.

[0074] Since the household appliance of the embodiment of the utility model adopts all the technical solutions of the motor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described in detail here.

[0075] 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 assembly, rotating about an axis of rotation, characterized in that: include: A rotor core and a plurality of permanent magnets, wherein the rotor core comprises a plurality of core units arranged around the rotation axis, mounting grooves are formed between adjacent core units, and the plurality of permanent magnets are respectively mounted in corresponding mounting grooves; The permanent magnet comprises a first magnetic portion and a second magnetic portion connected in sequence from outside to inside along the radial direction of the rotor assembly, wherein the width of the second magnetic portion away from an end of the first magnetic portion is smaller than the width of the first magnetic portion close to an end of the second magnetic portion; The core unit includes a fan-shaped portion and a magnetic bridge connected to the fan-shaped portion at one end close to the rotation axis. Along the circumference of the rotor assembly, the side walls of the fan-shaped portion on both sides of the mounting slot abut against the first magnetic portion, and the side walls of the magnetic bridge on both sides of the mounting slot abut against the second magnetic portion.

2. The rotor assembly according to claim 1, characterized in that: The widths of the first magnetic parts are equal, and the widths of the second magnetic parts gradually decrease along a direction approaching the rotation axis.

3. The rotor assembly according to claim 2, characterized in that: The width of the first magnetic portion is W1, and the minimum width of the second magnetic portion is W2, satisfying: W2<W1≤3*W2.

4. The rotor assembly according to claim 1 or 2, characterized in that: The minimum width of the second magnetic portion is W2, satisfying: W2 ≥ 1 mm.

5. The rotor assembly according to claim 1, characterized in that: The rotor core includes a plurality of rotor punchings stacked along the direction of the rotation axis, the maximum thickness of the rotor punchings is t, and the minimum width of the magnetic bridge is W. b , satisfying: W b ≥1.2*t.

6. The rotor assembly according to claim 1, characterized in that: Along the radial direction, the length of the first magnetic portion is L1, and the length of the second magnetic portion is L2, satisfying: 0.05≤L2 / L1≤0.

35.

7. The rotor assembly according to claim 1, characterized in that: The magnetic bridge includes a first connecting portion and a first protrusion, the first connecting portion is connected to the fan-shaped portion, and the first protrusion is connected to the side of the first connecting portion facing the mounting groove; along the circumferential direction, one of the two opposite sides of the second magnetic portion abuts against the first connecting portion; along the radial direction, the end wall of the second magnetic portion away from one end of the first magnetic portion abuts against the first protrusion.

8. The rotor assembly according to claim 7, characterized in that: The core unit includes a plurality of rotor punchings stacked along the direction of the rotation axis, the maximum thickness of the rotor punchings is t, and along the radial direction, the maximum thickness of the first protrusion is K1, satisfying: t≤K1≤3t.

9. The rotor assembly according to claim 1, characterized in that: The core unit also includes a second protrusion, which is connected to a side of the fan-shaped portion facing the mounting groove, and an end wall of the first magnetic portion away from one end of the second magnetic portion abuts against the second protrusion. Along the radial direction, the maximum thickness of the second protrusion is K2. The core unit includes a plurality of rotor punchings stacked along the direction of the rotation axis, and the maximum thickness of the rotor punchings is t, satisfying: t≤K2≤3t.

10. The rotor assembly according to claim 1, characterized in that: The magnetic bridge includes a first bridge segment and a second bridge segment connected in sequence along the radial direction of the rotor assembly, the second bridge segment is closer to the rotation axis than the first bridge segment, the width of the first bridge segment gradually decreases in the direction approaching the rotation axis, and the minimum width of the first bridge segment is greater than or equal to the maximum width of the second bridge segment.

11. The rotor assembly according to claim 1, characterized in that: The cross section of the second magnetic portion is square or trapezoidal; or The two side walls of the second magnetic portion along the circumferential direction are concave in directions approaching each other or convex in directions away from each other.

12. The motor is characterized by: A rotor assembly comprising any one of claims 1 to 11.

13. A household appliance, characterized in that: Including the motor as claimed in claim 12.

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