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 core, a shaft sleeve and a plurality of permanent magnets, mounting grooves are formed among a plurality of fan-shaped parts of the rotor core, and the permanent magnets are correspondingly arranged in the mounting grooves. The shaft sleeve is located on the inner side of the rotor core and is spaced from the rotor core, the multiple supporting ribs of the shaft sleeve are connected to the outer side wall of the annular part and are arranged at intervals in the circumferential direction of the annular part, and the multiple supporting ribs abut against the multiple permanent magnets in a one-to-one correspondence mode. The end, facing the rotating axis, of the permanent magnet protrudes out of the end, facing the rotating axis, of the fan-shaped part, so that the distance between the ends, facing the rotating axis, of the two adjacent fan-shaped parts can be prolonged, the magnetic resistance of a magnetic circuit is increased, and a magnetic field generated by the permanent magnet is difficult to form a loop at the ends, facing the rotating axis, of the two adjacent fan-shaped parts; therefore, the magnetic leakage of the rotor assembly can be reduced, the performance of the motor is improved, and the power density of the motor is further improved.

Description

Technical Field

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

[0002] The rotor assembly of an inner rotor motor includes a rotor core and a plurality of permanent magnets. The rotor core includes a plurality of sector parts, and the plurality of permanent magnets are correspondingly arranged between adjacent sector parts. Since a limiting part is arranged at the inner end of the sector part, and the limiting part is used to limit the position of the permanent magnet, the magnetic path of the permanent magnet easily enters the limiting part on the other side along the limiting part on one side and finally returns to the permanent magnet. This part of the magnetic path does not participate in the cooperation with the stator magnetic path, that is, magnetic leakage occurs, resulting in a reduction in the performance of the motor. Summary of the Utility Model

[0003] The utility model aims to at least solve one of the technical problems existing in the prior art. For this reason, the utility model provides a rotor assembly, which can reduce magnetic leakage and improve the performance of the rotor assembly.

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

[0005] The rotor assembly according to the first aspect embodiment of the utility model includes: a rotor core including a plurality of sector parts, the plurality of sector parts are arranged around the rotation axis of the rotor assembly, and an installation groove is formed between adjacent sector parts;

[0006] A plurality of permanent magnets are correspondingly installed in the installation groove;

[0007] A bushing is located inside the rotor core and is spaced from the rotor core. The bushing includes an annular part and a plurality of support ribs. The plurality of support ribs are connected to the outer side wall of the annular part and are arranged at intervals along the circumferential direction of the annular part. The plurality of support ribs are in one-to-one abutment with the plurality of permanent magnets;

[0008] Wherein, along the radial direction of the rotor assembly, one end of the permanent magnet facing the rotation axis protrudes relative to one end of the sector part facing the rotation axis.

[0009] The rotor assembly according to the embodiment of the utility model has at least the following beneficial effects:

[0010] A mounting groove is formed between the multiple sectors of the rotor core, and multiple permanent magnets are correspondingly arranged in the mounting groove. The sleeve is located on the inner side of the rotor core and is spaced apart from the rotor core. The multiple support ribs of the sleeve are connected to the outer side wall of the annular portion and are spaced apart along the circumference of the annular portion. The multiple support ribs and the multiple permanent magnets are abutted one by one, so the support ribs play a role in limiting the movement of the permanent magnets in the direction close to the rotation axis. Since one end of the permanent magnet facing the rotation axis protrudes from one end of the sector facing the rotation axis, the distance between the ends of the two adjacent sectors facing the rotation axis can be extended to increase the magnetic resistance of the magnetic circuit, so that the magnetic field generated by the permanent magnet is difficult to form a loop at the ends of the two adjacent sectors facing the rotation axis, thereby reducing the magnetic leakage of the rotor assembly, improving the performance of the motor, and further improving the power density of the motor.

[0011] According to some embodiments of the present invention, the radius of the maximum inscribed circle inside the plurality of permanent magnets is R1, and the radius of the maximum inscribed circle inside the plurality of sector portions is R2, satisfying: 0.8≤R1 / R2≤0.95.

[0012] According to some embodiments of the present invention, the radius of the maximum inscribed circle inside the plurality of permanent magnets is R1, and along the radial direction of the rotor assembly, the maximum length of the support rib is L, satisfying: 1 / 12≤L / R1≤5 / 12.

[0013] According to some embodiments of the present invention, the width of the end of the supporting rib away from the rotation axis narrows outwardly.

[0014] According to some embodiments of the present invention, one end of the supporting rib facing the permanent magnet is constructed as an outwardly convex arc surface.

[0015] According to some embodiments of the utility model, a limiting protrusion is provided on at least one side of one end of the sector portion away from the rotation axis, and the limiting protrusion protrudes toward the installation groove and abuts against one end of the permanent magnet away from the rotation axis.

[0016] According to some embodiments of the present invention, the rotor assembly further includes a plastic-coating portion, and the plastic-coating portion covers the permanent magnet and the sector-shaped portion.

[0017] According to some embodiments of the utility model, the annular portion is provided with a center hole, and the rotor assembly further includes a rotating shaft, which is passed through the center hole and fixedly connected to the annular portion.

[0018] The motor according to the second embodiment of the utility model includes the rotor assembly described in the above embodiment.

[0019] The motor according to the embodiment of the utility model has at least the following beneficial effects:

[0020] By adopting the rotor assembly of the first aspect embodiment, mounting grooves are formed between multiple sector portions of the rotor core, and multiple permanent magnets are correspondingly arranged in the mounting grooves. The sleeve is located inside the rotor core and is spaced from the rotor core. Multiple support ribs of the sleeve are connected to the outer sidewall of the annular portion and are spaced along the circumferential direction of the annular portion. The multiple support ribs are in one-to-one abutting connection with the multiple permanent magnets. Therefore, the support ribs play a role in restricting the movement of the permanent magnets in the direction close to the rotation axis. Since one end of the permanent magnet facing the rotation axis protrudes from one end of the sector portion facing the rotation axis, the distance between the ends of two adjacent sector portions facing the rotation axis can be extended to increase the magnetic resistance of the magnetic circuit, making it difficult for the magnetic field generated by the permanent magnets to form a loop at the ends of two adjacent sector portions facing the rotation axis. Therefore, the magnetic leakage of the rotor assembly can be reduced, the performance of the motor can be improved, and the power density of the motor can be further increased.

[0021] The household appliance according to the third aspect embodiment of the present invention includes the motor described in the above embodiment.

[0022] The household appliance according to the embodiment of the present invention has at least the following beneficial effects:

[0023] By adopting the motor of the second aspect embodiment, mounting grooves are formed between multiple sector portions of the rotor core of the motor, and multiple permanent magnets are correspondingly arranged in the mounting grooves. The sleeve is located inside the rotor core and is spaced from the rotor core. Multiple support ribs of the sleeve are connected to the outer sidewall of the annular portion and are spaced along the circumferential direction of the annular portion. The multiple support ribs are in one-to-one abutting connection with the multiple permanent magnets. Therefore, the support ribs play a role in restricting the movement of the permanent magnets in the direction close to the rotation axis. Since one end of the permanent magnet facing the rotation axis protrudes from one end of the sector portion facing the rotation axis, the distance between the ends of two adjacent sector portions facing the rotation axis can be extended to increase the magnetic resistance of the magnetic circuit, making it difficult for the magnetic field generated by the permanent magnets to form a loop at the ends of two adjacent sector portions facing the rotation axis. Therefore, the magnetic leakage of the rotor assembly can be reduced, the performance of the motor can be improved, and the power density of the motor can be further increased.

[0024] The additional aspects and advantages of the present invention will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0025] The following further describes the present invention in conjunction with the drawings and embodiments, where:

[0026] Figure 1 is a schematic structural diagram of a rotor assembly according to an embodiment of the present invention;

[0027] Figure 2 is an exploded view of a rotor assembly according to an embodiment of the present invention;

[0028] Figure 3 is a top view of a rotor assembly according to an embodiment of the present utility model, and schematically shows the magnetic circuit path;

[0029] Figure 4 is Figure 3 an enlarged view of part A in

[0030] Figure 5 is a top view of a rotor assembly according to an embodiment of the present utility model, and schematically shows the largest inscribed circle of the permanent magnet and the largest inscribed circle of the rotor core;

[0031] Figure 6 is a top view of a shaft sleeve according to an embodiment of the present utility model.

[0032] Reference numerals:

[0033] rotor assembly 1000;

[0034] rotor core 100; sector portion 110; limit projection 111; mounting groove 120; permanent magnet 200; shaft sleeve 300; annular portion 310; central hole 311; support rib 320; plastic-coated portion 400; rotating shaft 500. Detailed implementation manners

[0035] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation of the present utility model.

[0036] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as up, down, front, back, left, right, etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model 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 should not be construed as a limitation of the present utility model.

[0037] In the description of the present utility model, the meaning of several is one or more, the meaning of a plurality is two or more, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence of the indicated technical features.

[0038] In the description of the present utility model, unless otherwise clearly defined, terms such as "arrangement", "installation", and "connection" should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.

[0039] Referring to Figure 1 and Figure 2 As shown, a rotor assembly 1000 according to an embodiment of the present utility model can be used in an electric motor, and the electric motor can be used in household appliances such as air conditioners, refrigerators, humidifiers, and fans. The rotor assembly 1000 according to the embodiment of the present utility model includes a rotor core 100 and permanent magnets 200. The rotor core 100 includes a plurality of sector-shaped portions 110. The plurality of sector-shaped portions 110 are arranged around the rotation axis of the rotor assembly 1000, and an installation groove 120 is formed between adjacent sector-shaped portions 110. A plurality of permanent magnets 200 are provided and the number thereof is the same as that of the installation grooves 120. The plurality of permanent magnets 200 are correspondingly installed in the installation grooves 120. The bushing 300 is located inside the rotor core 100 and is spaced apart from the rotor core 100.

[0040] Referring to Figure 2 and Figure 3 As shown, the bushing 300 includes an annular portion 310 and support ribs 320. The annular portion 310 is in a cylindrical shape. A plurality of support ribs 320 are provided and the number thereof is the same as that of the permanent magnets 200. The plurality of support ribs 320 are connected to the outer side wall of the annular portion 310 and are spaced apart along the circumferential direction of the annular portion 310. One end of each of the plurality of support ribs 320 abuts against one end of each of the plurality of permanent magnets 200 facing the rotation axis, and the support ribs 320 function to limit the movement of the permanent magnets 200 in the direction close to the rotation axis. Among them, along the radial direction of the rotor assembly 1000, one end of the permanent magnet 200 facing the rotation axis protrudes from one end of the sector-shaped portion 110 facing the rotation axis. The number of the sector-shaped portions 110 can be an even number such as 4, 6, 8, 12, 14, etc.

[0041] It should be noted that, for the convenience of explanation, one end of the sector-shaped portion 110 and the permanent magnet 200 facing the rotation axis is referred to as the inner end portion, and the end portion away from the rotation axis is referred to as the outer end portion. Referring to Figure 3 as shown in Figure 3 The dotted line with an arrow in

[0042] Referring to Figure 4As shown, it can be understood that in the magnetic flux leakage magnetic circuit, the magnetic circuit enters the corresponding sector portion 110 from the N pole, enters the space formed by enclosing the inner side of the rotor core 100 through the inner end portion of the sector portion 110, then returns to the inner end portion of another adjacent sector portion 110, and finally returns to the S pole. This part of the magnetic circuit does not interact with the magnetic field of the stator assembly, that is, magnetic flux leakage is generated. It should be noted that Figure 4 the magnetic circuit in is only a schematic illustration for the convenience of explanation and does not mean that this magnetic circuit must exist. By adopting the above solution, since the inner end portion of the permanent magnet 200 protrudes from the inner end portion of the sector portion 110, the distance between the inner end portions of two adjacent sector portions 110 can be extended to increase the magnetic resistance of the magnetic circuit, making it difficult for the magnetic field generated by the permanent magnet 200 to form a loop between the inner end portions of two adjacent sector portions 110. Therefore, the magnetic flux leakage of the rotor assembly 1000 can be reduced, the performance of the motor can be improved, and the power density of the motor can be further improved.

[0043] Referring to Figure 5 As shown, in the embodiment of the present invention, the radius of the largest inscribed circle S1 inside the plurality of permanent magnets 200 is R1, and the radius of the largest inscribed circle S2 inside the plurality of sector portions 110 is R2, satisfying: 0.8 ≤ R1 / R2 ≤ 0.95. For example, the value of R1 / R2 can be 0.81, 0.83, 0.85, 0.87, 0.89, 0.91, 0.95, etc. It should be noted that the largest inscribed circle S1 inside the plurality of permanent magnets 200 is tangent to the inner end portions of the plurality of permanent magnets 200, and the largest inscribed circle S2 inside the plurality of sector portions 110 is tangent to the inner end portions of the plurality of sector portions 110. For example, along the circumferential direction of the rotor assembly 1000, rounded corners are provided on both sides of the inner end portion of the permanent magnet 200, and the connection between the rounded corner and the side wall of the permanent magnet 200 is aligned with the end wall of the inner end portion of the sector portion 110.

[0044] Since the key improvement of this embodiment lies in the size of the sector portion 110, and the size and position of the permanent magnet 200 are usually fixed, the value of R1 is generally a fixed value. When the value of R1 / R2 is less than 0.8, that is, the value of R2 is too large, the length of the sector portion 110 in the radial direction is short, and the main function of the sector portion 110 is to conduct magnetic flux. The reduction of the length of the sector portion 110 will lead to a decrease in the magnetic flux conduction ability and a reduction in the performance of the motor. When the value of R1 / R2 is greater than 0.95, that is, the value of R2 is relatively large, the inner end portions of the sector portions 110 are relatively close, and it is easy for the permanent magnet 200 to construct a magnetic circuit between the inner end portions of two adjacent sector portions 110, resulting in an increase in magnetic flux leakage and a reduction in the performance of the motor. Therefore, by reasonably designing the value of R1 / R2 to be between 0.8 and 0.95, it is possible to reduce the influence on the magnetic flux conduction performance of the sector portion 110 while avoiding the situation of increased magnetic flux leakage caused by the too-close distance between two adjacent sector portions 110, and the performance of the motor can be improved.

[0045] Referring to Figure 5 and Figure 6 As shown, in the embodiment of the present utility model, the radius of the largest inscribed circle inside the multiple permanent magnets 200 is R1, and along the radial direction of the rotor assembly 1000, the maximum length of the support rib 320 is L, satisfying: 1 / 12 ≤ L / R1 ≤ 5 / 12. For example, the value of L / R1 can be 1 / 12, 1 / 6, 1 / 4, 1 / 3, 5 / 12, etc. It should be noted that the maximum length L of the support rib 320 refers to: the distance from the smallest inscribed circle of the outer sidewall of the annular portion 310 to the top end of the support rib 320.

[0046] When L / R1 is less than 1 / 12, that is, the maximum length of the support rib 320 is short, while R1 is large, that is, the radial length of the permanent magnet 200 is short, the magnetic flux generated by the permanent magnet 200 decreases, and the output torque and speed of the motor decrease, resulting in a decline in the overall performance of the motor. When L / R1 is greater than 5 / 12, R1 is small, that is, the radial length of the permanent magnet 200 increases. Since the outer diameter of the rotating shaft 500 is fixed and the outer diameter of the annular portion 310 is usually also fixed, when the radial length of the permanent magnet 200 increases, the maximum length of the support rib 320 can only decrease, resulting in the distance between the inner end of the fan-shaped portion 110 and the annular portion 310 being relatively close, which easily causes the magnetic circuit of the permanent magnet 200 to enter the annular portion 310 and the support rib 320 through the inner end of the fan-shaped portion 110, and finally enter the inner end of the adjacent other fan-shaped portion 110, resulting in an increase in magnetic leakage. Therefore, by reasonably designing the ratio range of L / R1 between 1 / 12 and 5 / 12, the length of the permanent magnet 200 can be made appropriate, and at the same time, magnetic leakage can be reduced to improve the overall performance of the motor.

[0047] Referring to Figure 6 As shown, in the embodiment of the present utility model, the width of the end of the support rib 320 away from the rotation axis narrows outward. It should be noted that the width of the support rib 320 refers to the width of the support rib 320 along the circumferential direction of the rotor assembly 1000; narrowing outward means that along the direction away from the rotation axis, the end width of the support rib 320 gradually decreases. Among them, the support rib 320 can be such that only the width at the end gradually decreases and the width of other parts remains unchanged; or the width of the entire support rib 320 gradually decreases. Adopting this solution can increase the distance between the inner end of the fan-shaped portion 110 and the support rib 320 to reduce magnetic leakage; at the same time, it can ensure that the support rib 320 has appropriate strength to reduce the situation of deformation and bending of the support rib 320 and improve the reliability of the support rib 320. As an alternative embodiment, the circumferential width of the support rib 320 along the rotor assembly 1000 can also remain unchanged, or increase first and then decrease, or decrease first and then increase, and a suitable solution can be selected according to the actual situation.

[0048] Continuing to refer toFigure 6 As shown in Figure 6 , in the embodiment of the present utility model, one end of the support rib 320 facing the permanent magnet 200 is configured as a convex arc surface. For example, the arc surface can be a circular arc surface, an elliptical arc surface, etc. One end of the support rib 320 is set in the form of a convex arc surface, and the arc surface can better adapt to the shape of the inner end of the permanent magnet 200, reduce stress concentration points, and at the same time reduce the occurrence of scratches on the surface of the permanent magnet 200, improving the stability and reliability of the connection of the permanent magnet 200. It should be noted that "convex" means that one end of the support rib 320 protrudes in the direction of the corresponding permanent magnet 200. As an alternative embodiment, the cross-section of one end of the support rib 320 facing the permanent magnet 200 can also be a tip shape, that is, the cross-section is triangular, and a suitable solution is selected according to the actual situation.

[0049] Refer to Figure 3 As shown in Figure 3 , in the embodiment of the present utility model, at least one side of the outer end of the sector portion 110 is provided with a limiting protrusion 111. The limiting protrusion 111 protrudes towards the installation groove 120 and abuts against the outer end of the permanent magnet 200, thereby restricting the permanent magnet 200 from detaching from the installation groove 120 in the direction away from the rotation axis. It can be understood that the outer end of the permanent magnet 200 is limited by the limiting protrusion 111, and the inner end of the permanent magnet 200 is limited by the support rib 320, which can conveniently determine the relative position between the permanent magnet 200 and the rotor core 100, and at the same time can effectively restrict the permanent magnet 200 from detaching from the installation groove 120, improving the stability and reliability of the installation of the permanent magnet 200.

[0050] Continue to refer to Figure 3 As shown in Figure 3 , in the embodiment of the present utility model, limiting protrusions 111 are provided on both sides of the outer end of the sector portion 110. The two limiting protrusions 111 located in the same installation groove 120 are arranged at intervals, that is, a notch is formed between the two limiting protrusions 111 located in the same installation groove 120. It can be understood that setting two limiting protrusions 111 in the same installation groove 120 can further improve the stability of limiting the permanent magnet 200 to reduce the situation of the permanent magnet 200 detaching from the installation groove 120. And magnetic leakage may also occur at the limiting protrusion 111. Compared with the case where the two limiting protrusions 111 are directly connected, when the two limiting protrusions 111 located in the same installation groove 120 are arranged at intervals, magnetic leakage can be reduced. The narrower the width of the notch, the greater the magnetic leakage, but the better the stability of limiting the permanent magnet 200. Therefore, in order to balance magnetic leakage and limiting, the size of the notch can be reasonably designed, and the present utility model does not specifically limit it here.

[0051] As an alternative embodiment, only one limiting protrusion 111 is provided at the outer end of the sector portion 110. Alternatively, it can also be that only one limiting protrusion 111 is provided on one side of the outer end of a part of the sector portion 110, and one limiting protrusion 111 is provided on each side of the outer end of the other part of the sector portion 110, as long as there is at least one limiting protrusion 111 in each installation groove 120. Specifically, select a suitable solution according to the actual situation.

[0052] Referring Figure 1 and Figure 2 As shown in the embodiments of the present invention, the rotor assembly 1000 further includes a plastic coating portion 400, and the plastic coating portion 400 covers the permanent magnet 200 and the sector portion 110. By adopting the plastic coating method, the stability and reliability of the connection between the permanent magnet 200 and the sector portion 110 are improved, effectively preventing the permanent magnet 200 from axially disengaging from the installation groove 120 along the motor, reducing the complexity of the assembly of the rotor assembly 1000, and improving the insulation performance of the motor, effectively preventing the phenomenon of electric corrosion. The rotor assembly 1000 after plastic coating treatment has higher chemical resistance and waterproofness, and can maintain good performance and a long service life even in harsh environments.

[0053] Referring Figure 1 and Figure 2 As shown in the embodiments of the present invention, the annular portion 310 is provided with a central hole 311, and the rotor assembly 1000 further includes a rotating shaft 500. The rotating shaft 500 passes through the central hole 311 and is fixedly connected to the annular portion 310. Among them, the rotating shaft 500 is also fixedly connected to the annular portion 310 by means of plastic coating, or connected by means of fasteners, welding, etc. When the rotor assembly 1000 rotates, it can drive the rotating shaft 500 to rotate synchronously, and the rotating shaft 500 then drives the relevant structures to rotate. Therefore, the rotor assembly 1000 has a simple structure and high reliability.

[0054] Referring Figure 1 As shown in the embodiments of the present invention, along the axial direction of the motor, both ends of the permanent magnet 200 protrude from the rotor core 100. When the permanent magnet 200 axially protrudes from the rotor core 100, a salient pole effect will be formed, making the direct-axis inductance and quadrature-axis inductance of the motor unequal. This inductance asymmetry will generate reluctance torque, which acts together with the permanent magnet torque, thereby increasing the output torque of the motor. The addition of reluctance torque helps to improve the efficiency of the motor, enabling it to output a larger torque at the same power, or consume less energy at the same torque. In some occasions that require high-speed operation, the motor needs to have good field weakening speed increasing ability. The protruding design of the permanent magnet 200 helps the motor to reduce the back electromotive force through field weakening control during high-speed operation, thereby maintaining the stable operation of the motor. This design enables the motor to maintain high efficiency and performance within a wide speed regulation range.

[0055] In an embodiment of the present utility model, the permanent magnet 200 can be made of materials such as ferrite, neodymium iron boron, alnico or samarium cobalt. Ferrite is a non-metallic permanent magnet material, and commonly used ones are barium ferrite and strontium ferrite. Its advantages are high cost performance, no precious metals such as rare earth elements, cobalt, nickel, etc., simple manufacturing process, large coercivity and strong anti-demagnetization ability. Neodymium iron boron is the most widely used rare earth permanent magnet material at present, which has a relatively high magnetic energy product and intrinsic coercivity, so it is widely used in high-performance permanent magnet motors. The preparation process and technology of alnico are relatively mature, and its main advantages are high remanence, low temperature coefficient and stable magnetism. Samarium cobalt is a rare earth permanent magnet material with excellent magnetic properties, relatively high remanence magnetic density and coercivity, and is mainly used in high-performance permanent magnet motors.

[0056] A motor according to an embodiment of the present utility model includes a stator assembly and the rotor assembly 1000 of the above embodiment, and the stator assembly is sleeved outside the rotor assembly 1000. For the motor according to an embodiment of the present utility model, the rotor assembly 1000 of the above embodiment is adopted. Installation grooves 120 are formed between multiple fan-shaped portions 110 of the rotor core 100, and multiple permanent magnets 200 are correspondingly arranged in the installation grooves 120. The bushing 300 is located inside the rotor core 100 and is spaced from the rotor core 100. Multiple support ribs 320 of the bushing 300 are connected to the outer side wall of the annular portion 310 and are spaced along the circumferential direction of the annular portion 310. Multiple support ribs 320 and multiple permanent magnets 200 are in one-to-one abutment, so the support ribs 320 play a role in restricting the movement of the permanent magnets 200 in the direction close to the rotation axis. Since the inner end of the permanent magnet 200 protrudes from the inner end of the fan-shaped portion 110, the distance between the inner ends of two adjacent fan-shaped portions 110 can be extended to increase the magnetic resistance of the magnetic circuit, making it difficult for the magnetic field generated by the permanent magnet 200 to form a loop at the inner ends of two adjacent fan-shaped portions 110. Therefore, the magnetic leakage of the rotor assembly 1000 can be reduced, the performance of the motor can be improved, and the power density of the motor can be further improved.

[0057] Since the motor 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 elaborated here.

[0058] An embodiment of the household appliance of the present utility model can be electrical appliances such as air conditioners, refrigerators, humidifiers, fans, etc. The household appliance includes the motor of the above embodiment. The household appliance of the embodiment of the present utility model adopts the motor of the above embodiment. Installation grooves 120 are formed between multiple fan-shaped portions 110 of the rotor core 100 of the motor, and multiple permanent magnets 200 are correspondingly arranged in the installation grooves 120. The sleeve 300 is located inside the rotor core 100 and is spaced from the rotor core 100. Multiple support ribs 320 of the sleeve 300 are connected to the outer sidewall of the annular portion 310 and are arranged at intervals along the circumferential direction of the annular portion 310. The multiple support ribs 320 are in one-to-one abutment with the multiple permanent magnets 200. Therefore, the support ribs 320 play a role in restricting the movement of the permanent magnets 200 in the direction close to the rotation axis. Since the inner end portion of the permanent magnet 200 protrudes from the inner end portion of the fan-shaped portion 110, the distance between the inner end portions of two adjacent fan-shaped portions 110 can be extended to increase the magnetic resistance of the magnetic circuit, making it difficult for the magnetic field generated by the permanent magnet 200 to form a loop between the inner end portions of two adjacent fan-shaped portions 110. Therefore, the magnetic leakage of the rotor assembly 1000 can be reduced, the performance of the motor can be improved, and the power density of the motor can be further improved.

[0059] 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 elaborated here.

[0060] The embodiments of the present utility model have been described in detail above with reference to the drawings. However, the present utility model is not limited to the above embodiments. Various changes can be made without departing from the purpose of the present utility model within the knowledge scope of those of ordinary skill in the art.

Claims

1. Rotor assembly, characterized in that, include: The rotor core comprises a plurality of sector-shaped parts, wherein the plurality of sector-shaped parts are arranged around the rotation axis of the rotor assembly, and mounting grooves are formed between adjacent sector-shaped parts; A plurality of permanent magnets are installed in the installation slots correspondingly; A sleeve, located on the inner side of the rotor core and spaced apart from the rotor core, the sleeve comprising an annular portion and a plurality of support ribs, the plurality of support ribs being connected to the outer side wall of the annular portion and spaced apart along the circumference of the annular portion, the plurality of support ribs being in one-to-one contact with the plurality of permanent magnets; Wherein, along the radial direction of the rotor assembly, one end of the permanent magnet facing the rotation axis protrudes relative to one end of the sector portion facing the rotation axis.

2. The rotor assembly according to claim 1, wherein: The radius of the largest inscribed circle inside the plurality of permanent magnets is R1, and the radius of the largest inscribed circle inside the plurality of fan-shaped portions is R2, satisfying: 0.8≤R1 / R2≤0.

95.

3. The rotor assembly according to claim 1, wherein: The radius of the largest inscribed circle inside the plurality of permanent magnets is R1, and along the radial direction of the rotor assembly, the maximum length of the support rib is L, satisfying: 1 / 12≤L / R1≤5 / 12.

4. The rotor assembly according to claim 1, wherein: The width of the end of the supporting rib away from the rotation axis narrows outwards.

5. The rotor assembly according to claim 4, characterized in that: One end of the supporting rib facing the permanent magnet is configured as an outwardly convex arc surface.

6. The rotor assembly according to claim 1, characterized in that: A limiting protrusion is provided on at least one side of one end of the sector-shaped portion away from the rotation axis. The limiting protrusion protrudes toward the mounting groove and abuts against one end of the permanent magnet away from the rotation axis.

7. The rotor assembly according to claim 1, wherein: The rotor assembly further includes a plastic-encapsulating portion, which encapsulates the permanent magnet and the sector-shaped portion.

8. The rotor assembly according to claim 1, characterized in that: The annular portion is provided with a central hole, and the rotor assembly further comprises a rotating shaft, which is passed through the central hole and fixedly connected to the annular portion.

9. Electric motor, characterized in that: Comprising a rotor assembly as claimed in any one of claims 1 to 8.

10. Household appliance, characterized in that: Comprising the motor as claimed in claim 9.

Images