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 shaft sleeve, a plurality of fan-shaped parts and a plurality of permanent magnets, the fan-shaped parts are arranged at intervals in the circumferential direction of the rotor assembly, the shaft sleeve is located in a space defined by the fan-shaped parts, and the permanent magnets are correspondingly installed in installation grooves between the adjacent fan-shaped parts. The end, facing the rotating axis, of the permanent magnet protrudes out of the end, facing the rotating axis, of the fan-shaped part and abuts against the shaft sleeve. The position of one end, facing the rotating axis, of the permanent magnet does not need to be limited through a fan-shaped part, and magnetic leakage caused by arrangement of a limiting structure can be reduced. And meanwhile, the diameter D2 of the maximum inscribed circle of the plurality of permanent magnets is limited in a range from D1 + 2 * t to D1 + 2 * t + 6mm, so that the distance between the permanent magnets and the annular part is ensured to be close enough, the volume of the permanent magnets can be increased, the magnetic flux density is increased, the output power of the motor is increased, the counter electromotive force is increased, and the performance of the motor can be 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 multiple permanent magnets. The rotor core comprises multiple sectors, with the permanent magnets positioned between adjacent sectors. Because the sectors are required to position the permanent magnets, the size of the permanent magnets is limited, making it difficult to increase the size while maintaining the same motor's outer diameter. This hinders motor performance. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems in the prior art. To this end, the present invention provides a rotor assembly capable of increasing the volume of a permanent magnet.

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

[0005] According to the first embodiment of the present invention, the rotor assembly comprises: a plurality of sector-shaped portions; the sector-shaped portions are arranged at intervals along the circumferential direction of the rotation axis of the rotor assembly, and mounting grooves are formed between adjacent sector-shaped portions;

[0006] A shaft sleeve is arranged in a space enclosed by the plurality of sector-shaped portions and is spaced apart from the sector-shaped portions;

[0007] A plurality of permanent magnets are mounted in the plurality of mounting slots in a one-to-one correspondence, wherein one end of the permanent magnet facing the rotation axis protrudes from one end of the sector portion facing the rotation axis, and the permanent magnets abut against the outer wall of the sleeve;

[0008] The sleeve is provided with an inner hole for the rotating shaft to pass through, the maximum inner diameter of the inner hole is D1, the minimum thickness of the sleeve is t, the diameter of the maximum inscribed circle inside the plurality of permanent magnets is D2, and the condition: D1+2*t≤D2≤D1+2*t+6mm is satisfied.

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

[0010] By arranging a plurality of fan-shaped portions spaced apart along the circumference of the rotor assembly, the shaft sleeve is located in the space enclosed by the plurality of fan-shaped portions, and the permanent magnets are correspondingly installed in the mounting grooves between adjacent fan-shaped portions. Wherein, one end of the permanent magnet facing the rotation axis protrudes from the other end of the fan-shaped portion facing the rotation axis and abuts against the outer wall of the shaft sleeve. Therefore, it is not necessary to utilize the fan-shaped portion to limit the position of the end of the permanent magnet facing the rotation axis, which can reduce the leakage flux caused by the setting of the limiting structure. At the same time, since one end of the permanent magnet protrudes from the fan-shaped portion, the length of the permanent magnet in the radial direction is longer, and the diameter D2 of the maximum inscribed circle of the plurality of permanent magnets is limited to within the range of D1+2*t to D1+2*t+6mm, ensuring that the distance between the permanent magnet and the annular portion is close enough, which can increase the volume of the permanent magnet, increase the magnetic flux density, increase the output power of the motor, increase the back electromotive force, and improve the performance of the motor.

[0011] According to some embodiments of the present invention, the sleeve further includes a plurality of support ribs, which are arranged on the outer wall of the annular portion and spaced apart along the circumference of the annular portion, and the plurality of support ribs and the plurality of permanent magnets are in one-to-one contact with each other.

[0012] According to some embodiments of the present invention, along the radial direction of the rotor assembly, the maximum length of the permanent magnet is L, and along the circumferential direction of the rotor assembly, the maximum width of the permanent magnet is W, satisfying: 1.5≤L / W≤3.5.

[0013] According to some embodiments of the present invention, the end of the sector portion away from the rotation axis includes a first arc surface, the center of the first arc surface coincides with the rotation axis, and the angle of the first arc surface relative to the central angle of the rotation axis is θ, satisfying: 3°≤θ≤15°.

[0014] According to some embodiments of the present invention, the end of the sector portion away from the rotation axis further includes a second arc surface inscribed in the first arc surface, and the radius of the second arc surface is smaller than the radius of the first arc surface.

[0015] According to some embodiments of the present invention, the radius of the second arc surface is R, which satisfies: 1.5 mm ≤ R ≤ 10 mm.

[0016] According to some embodiments of the present invention, the number of the sector-shaped portions and the number of the permanent magnets are both fourteen, or the number of the sector-shaped portions and the number of the permanent magnets are both ten.

[0017] According to some embodiments of the present invention, a limiting protrusion is provided on at least one side of the sector portion away from the rotation axis, and the limiting protrusion protrudes toward the mounting groove and abuts against the end of the permanent magnet away from the rotation axis.

[0018] According to some embodiments of the present invention, the number of the fan-shaped portions and the permanent magnets are both fourteen, the fan-shaped portion includes a first punching sheet group, a second punching sheet group and a third punching sheet group, the first punching sheet group and the third punching sheet group are respectively connected to the two ends of the second punching sheet group along the axial direction of the rotor assembly, the first punching sheet group and the third punching sheet group are provided with the limiting protrusions on both sides of the end away from the rotation axis, and the fan-shaped portion forms a notch between the first punching sheet group and the third punching sheet group.

[0019] According to some embodiments of the present invention, along the circumference of the rotor assembly, the maximum protruding distance of the limiting protrusion is s, which satisfies: 1mm≤s≤2mm.

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

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

[0022] By adopting the rotor assembly of the first aspect embodiment, the rotor assembly is arranged at intervals along the circumference of the rotor assembly by setting a plurality of fan-shaped portions, the sleeve is located in the space enclosed by the plurality of fan-shaped portions, and the permanent magnets are correspondingly installed in the mounting grooves between adjacent fan-shaped portions. Among them, one end of the permanent magnet facing the rotation axis protrudes from the other end of the fan-shaped portion facing the rotation axis and abuts against the outer wall of the sleeve. Therefore, it is not necessary to use the fan-shaped portion to limit the position of the end of the permanent magnet facing the rotation axis, which can reduce the leakage magnetic flux caused by the setting of the limiting structure. At the same time, because one end of the permanent magnet protrudes from the fan-shaped portion, the length of the permanent magnet in the radial direction is longer, and the diameter D2 of the maximum inscribed circle of the plurality of permanent magnets is limited to within the range of D1+2*t to D1+2*t+6mm, ensuring that the distance between the permanent magnet and the annular portion is close enough, which can increase the volume of the permanent magnet, increase the magnetic flux density, increase the output power of the motor, increase the back electromotive force, and improve the performance of the motor.

[0023] A household appliance according to an embodiment of the third aspect of the present invention includes the motor described in the above embodiment.

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

[0025] By adopting the motor of the second aspect embodiment, the rotor assembly of the motor is arranged at intervals along the circumference of the rotor assembly by arranging multiple fan-shaped portions, the sleeve is located in the space enclosed by the multiple fan-shaped portions, and the permanent magnet is correspondingly installed in the mounting groove between adjacent fan-shaped portions. Wherein, one end of the permanent magnet facing the rotation axis protrudes from the one end of the fan-shaped portion facing the rotation axis and abuts the outer wall of the sleeve. Therefore, it is not necessary to utilize the fan-shaped portion to limit the position of the one end of the permanent magnet facing the rotation axis, which can reduce the leakage flux caused by the setting of the limiting structure. At the same time, because one end of the permanent magnet protrudes from the fan-shaped portion, the length of the permanent magnet in the radial direction is longer, and the diameter D2 of the maximum inscribed circle of the multiple permanent magnets is limited to within the range of D1+2*t to D1+2*t+6mm, ensuring that the distance between the permanent magnet and the annular portion is close enough, which can increase the volume of the permanent magnet, increase the magnetic flux density, increase the output power of the motor, increase the back electromotive force, and improve the performance of the motor.

[0026] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0028] Figure 1 This is an exploded schematic diagram of a rotor assembly according to an embodiment of the present invention;

[0029] Figure 2 This is a top view of a rotor assembly according to an embodiment of the present invention;

[0030] Figure 3 is a top view of a rotor assembly according to another embodiment of the present invention;

[0031] Figure 4 This is a structural diagram of a shaft sleeve according to an embodiment of the present utility model;

[0032] Figure 5 This is a schematic structural diagram of a permanent magnet according to an embodiment of the present invention;

[0033] Figure 6 This is a schematic structural diagram of a fan-shaped portion of an embodiment of the present invention;

[0034] Figure 7 It is a structural schematic diagram of the fan-shaped portion of an embodiment of the present invention from another perspective.

[0035] Reference numerals:

[0036] Rotor assembly 1000; sector 100; mounting groove 110; limiting protrusion 120; first arc surface 130; second arc surface 140; notch 150; first punching sheet group 160; second punching sheet group 170; third punching sheet group 180; notch 190; sleeve 200; inner hole 210; annular portion 220; support rib 230; permanent magnet 300; overmolded portion 400. DETAILED DESCRIPTION

[0037] The following describes embodiments of the present invention in detail. 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0038] 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 orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying 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.

[0039] In the description of this utility model, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0040] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting 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.

[0041] Reference Figure 1 and Figure 2As shown, a rotor assembly 1000 of an embodiment of the present invention is used for a motor, which can be used in household appliances such as air conditioners, refrigerators, electric fans, and dehumidifiers. The rotor assembly 1000 of the present invention includes a fan-shaped portion 100, a sleeve 200, and a plurality of permanent magnets 300. The fan-shaped portion 100 is provided with a plurality of fan-shaped portions and is spaced circumferentially along the rotation axis of the rotor assembly 1000. An installation groove 110 is formed between adjacent fan-shaped portions 100. The sleeve 200 is annular and is arranged in the space enclosed by the plurality of fan-shaped portions 100 and is spaced apart from the fan-shaped portions 100. The plurality of permanent magnets 300 are installed in a one-to-one correspondence in the plurality of installation grooves 110. Along the radial direction of the rotor assembly 1000, the inner end of the permanent magnet 300 protrudes from the inner end of the fan-shaped portion 100, and the inner end of the permanent magnet 300 abuts and cooperates with the sleeve 200, thereby limiting the position of the permanent magnet 300. For example, the number of the sectors 100 is the same as the number of the permanent magnets 300. For example, the number of the sectors 100 can be an even number such as 4, 6, 8, 10, 12, or 14. Figure 2 The number of permanent magnets 300 is 14. Figure 3 The number of the permanent magnets 300 is ten.

[0042] It should be noted that the inner end of the permanent magnet 300 refers to the end of the permanent magnet 300 close to the rotation axis, and the outer end of the permanent magnet 300 refers to the end of the permanent magnet 300 away from the rotation axis; the inner end of the fan-shaped portion 100 refers to the end of the fan-shaped portion 100 close to the rotation axis, and the outer end of the fan-shaped portion 100 refers to the end of the fan-shaped portion 100 away from the rotation axis.

[0043] Among them, reference Figure 2 and Figure 4 As shown, the sleeve 200 has an inner hole 210 for the shaft to pass through. The maximum inner diameter of the inner hole 210 is D1, the minimum thickness of the sleeve 200 is t, and the diameter of the largest inscribed circle inside the plurality of permanent magnets 300 is D2, satisfying the following: D1+2*t≤D2≤D1+2*t+6mm. For example, the value of D2 can be D1+2*t, D1+2*t+1mm, D1+2*t+1mm, D1+2*t+3mm, D1+2*t+4mm, and D1+2*t+6mm. When D2 is greater than D1+2*t+6mm, that is, the radial length of the permanent magnet 300 is shorter, the volume is smaller, the magnetic flux density is lower, and the output power of the motor is lower.

[0044] It is understandable that by adopting the above solution, since the inner end of the permanent magnet 300 and the sleeve 200 are in abutment and positioned, there is no need to use the sector 100 to limit the position of the inner end of the permanent magnet 300, which can reduce the leakage magnetic flux caused by setting the limiting structure. At the same time, since the inner end of the permanent magnet 300 protrudes from the inner end of the sector 100, the length of the permanent magnet 300 in the radial direction is longer, and the diameter D2 of the maximum inscribed circle of the multiple permanent magnets 300 is limited to within the range of D1+2*t to D1+2*t+6mm, ensuring that the distance between the permanent magnet 300 and the annular portion 220 is close enough, which can increase the volume of the permanent magnet 300, increase the magnetic flux density, increase the output power of the motor, increase the back electromotive force, and improve the performance of the motor.

[0045] It's important to note that back EMF refers to the electromotive force (EMF) generated when a motor is driven by voltage or current, generating an electromotive force in the opposite direction of the external force. This phenomenon is caused by the principle of electromagnetic induction. When a conductor moves in a magnetic field, a current is generated in the conductor, creating an electromotive force in the opposite direction of the external force. Increasing back EMF can improve motor stability, increase torque, and reduce heat loss. However, decreasing back EMF can degrade motor performance, causing poor operational stability and increasing heat loss.

[0046] Reference Figure 2 and Figure 4 As shown, in an embodiment of the present invention, the sleeve 200 includes an annular portion 220 and a plurality of support ribs 230. The annular portion 220 is provided with an inner hole 210 for the rotating shaft to pass through. The number of support ribs 230 is the same as the number of permanent magnets 300. The plurality of support ribs 230 are provided on the outer side wall of the annular portion 220 and are spaced apart along the circumference of the annular portion 220. The ends of the plurality of support ribs 230 away from the annular portion 220 are positioned in abutment with the plurality of permanent magnets 300 in a one-to-one correspondence. The support ribs 230 and the annular portion 220 may be connected in an integral manner or by welding, clamping, etc. The use of an integral molding solution can simplify the structure of the sleeve 200 and improve the stability and reliability of the connection between the support ribs 230 and the annular portion 220. The maximum length of the support ribs 230 protruding radially from the annular portion 220 is less than or equal to 6 mm. As an alternative embodiment, refer to Figure 3 As shown, the sleeve 200 is an annular portion 220 , and the permanent magnet 300 directly abuts against the annular portion 220 . An appropriate solution is selected according to actual conditions.

[0047] By adopting the above solution, since the inner end of the permanent magnet 300 protrudes from the inner end of the sector-shaped portion 100, the distance between the inner ends of two adjacent sector-shaped portions 100 can be extended to increase the magnetic resistance of the magnetic circuit, making it difficult for the magnetic field generated by the permanent magnet 300 to form a loop at the inner ends of two adjacent sector-shaped portions 100. Therefore, the leakage magnetic flux 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.

[0048] Reference Figure 5 As described above, in an embodiment of the present invention, along the radial direction of the rotor assembly 1000, the maximum length of the permanent magnet 300 is L, and along the circumferential direction of the rotor assembly 1000, the maximum width of the permanent magnet 300 is W, satisfying: 1.5≤L / W≤3.5. For example, the value of L / W can be 1.5, 2, 2.2, 2.5, 2.6, 2.8, 3, 3.05, 3.5. For example, when the number of permanent magnets 300 is fourteen, the value range of L / W is between 2 and 3.5. When the number of permanent magnets 300 is ten, the value range of L / W is between 1.5 and 3. It can be understood that L / W reflects the volume size relationship of the permanent magnet 300. When L / W is less than 2, the maximum length of the permanent magnet 300 is shorter, the maximum width is larger, and the thickness is increased. Generally speaking, the permanent magnet 300 itself also has magnetic resistance, and the direction of the magnetic circuit is along the width direction of the permanent magnet 300. Therefore, as the thickness of the permanent magnet 300 increases, the magnetic resistance will also increase, the magnetic circuit loss will increase, and the efficiency of the motor will decrease. When L / W is greater than 3.5, that is, the maximum length of the permanent magnet 300 is longer and the maximum width is smaller. The permanent magnet 300 is thinner, the volume of the permanent magnet 300 is reduced, and the magnetic flux is insufficient, which will also lead to reduced performance of the motor. Therefore, by rationally designing the value of L / W within the range of 2 to 3.5, so that the length and width of the permanent magnet 300 are appropriate, the relationship between magnetic resistance and magnetic flux can be balanced to improve the performance of the motor.

[0049] Reference Figure 6As shown, in an embodiment of the present invention, the end surface of the outer end of the sector 100 includes a first arc surface 130. The center of the first arc surface 130 coincides with the rotation axis, and the central angle corresponding to the first arc surface 130 is θ, which satisfies the following: 3°≤θ≤15°. For example, the value of θ can be 3°, 5°, 8.43°, 9.26°, 12°, or 15°. It should be noted that the angle θ of the central angle of the first arc surface 130 relative to the rotation axis refers to the central angle of one first arc surface 130. When θ is less than 3°, the proportion of the first arc surface 130 is too small. Although the distortion rate is reduced and the noise of the motor operation is low, the back electromotive force is reduced, resulting in poor motor operation stability and increased heat loss. When θ is greater than 15°, the proportion of the first arc surface 130 increases. Although the back electromotive force increases, the motor operation is smoother and the heat loss is reduced, but the distortion rate increases and the motor operation noise increases.

[0050] Therefore, the central angle of the first arc surface 130 is reasonably designed to be within the range of 3° to 15° to balance the relationship between the back electromotive force and the distortion rate, thereby reducing the distortion rate while increasing the back electromotive force, thereby improving the smoothness of the motor during operation, reducing heat loss, and reducing the noise during motor operation, thereby improving the user experience.

[0051] Continue to refer to Figure 6 As shown, in an embodiment of the present invention, the outer end portion of the sector portion 100 further includes a second arc surface 140, the second arc surface 140 is connected to the first arc surface 130, and is inscribed in the first arc surface 130, and the radius of the second arc surface 140 is smaller than the radius of the first arc surface 130. Wherein, the first arc surface 130 can be connected to the second arc surface 140 at both ends along the axial direction. It can be understood that by setting the second arc surface 140 to be inscribed in the first arc surface 130, and the radius of the second arc surface 140 is smaller than the radius of the first arc surface 130, the air gap between the rotor assembly 1000 and the stator assembly can become uneven, and the uneven distribution helps to reduce the pulsating impact during the transition of the magnetic poles, thereby reducing the noise and vibration generated by the rotor assembly 1000 during high-speed rotation, thereby achieving the effect of optimizing the performance of the motor.

[0052] Reference Figure 6As shown, in an embodiment of the present invention, the radius of the second arc surface 140 is R, which satisfies: 1.5mm≤R≤10mm. For example, the value of R can be 1.5mm, 2mm, 3mm, 5mm, 6mm, or 10mm. When R is less than 1.5mm, since the magnetic circuit needs to pass through the air gap from the outer end of the sector 100 to enter the stator assembly, R is too small, which will increase the air gap width at the second arc surface 140 and the distance traveled by the magnetic circuit. Since the magnetic resistance of air is large, the magnetic resistance and magnetic circuit loss will increase. When R is greater than 10mm, it is closer to the radius of the first arc surface 130, making it difficult to achieve the arc cutting effect, that is, the air gap between the rotor assembly 1000 and the stator assembly becomes too uniform, making it difficult to reduce the pulsating impact during the magnetic pole transition, resulting in the rotor assembly 1000 generating greater noise and vibration when rotating at high speed. Therefore, a reasonable design of the radius R of the second arc surface 140 within the range of 1.5 mm to 10 mm can improve the unevenness of the air gap while minimizing the distance traveled by the magnetic circuit, thereby reducing magnetic resistance and magnetic circuit loss, and helping to reduce the pulsating impact during the transition of the magnetic poles, thereby reducing the noise and vibration generated by the rotor assembly 1000 during high-speed rotation.

[0053] Reference Figure 2 and Figure 7 As shown, in an embodiment of the present invention, a notch 150 is formed between the outer ends of two adjacent sector portions 100 to communicate with the mounting slot 110. The outer end of the sector portion 100 is provided with a limiting protrusion 120 on at least one side of the notch 150, for example, both sides of the outer end of the sector portion 100 are provided with a limiting protrusion 120. The limiting protrusion 120 protrudes toward the mounting slot 110, and the limiting protrusion 120 and the outer end of the permanent magnet 300 abut and limit, thereby limiting the permanent magnet 300 from escaping from the mounting slot 110 from the notch 150. It is understandable that the outer end of the permanent magnet 300 is limited by the limiting protrusion 120, and the inner end of the permanent magnet 300 is limited by the support rib 230, which can facilitate the determination of the relative position between the permanent magnet 300 and the rotor core, and can effectively limit the permanent magnet 300 from escaping from the mounting slot 110, thereby improving the stability and reliability of the installation of the permanent magnet 300.

[0054] Reference Figure 7As shown, in the embodiment of the present invention, the number of permanent magnets 300 and the number of sector portions 100 are both fourteen. The sector portion 100 includes a first sheet group 160, a second sheet group 170, and a third sheet group 180. The first sheet group 160 and the third sheet group 180 are respectively connected to the two ends of the second sheet group 170 along the axial direction of the rotor assembly 1000. Both sides of the first sheet group 160 and the third sheet group 180 away from the rotation axis are provided with limiting protrusions 120. A gap 190 is formed between the first sheet group 160 and the third sheet group 180 of the sector portion 100, that is, there are no limiting protrusions 120 on both sides of the end of the second sheet group 170 away from the rotation axis, so that the gap 190 can be formed. It is understandable that since magnetic flux leakage is easily generated at the limiting protrusions 120, but the limiting protrusions 120 are needed to prevent the permanent magnet 300 from leaving the mounting slot 110, a solution is adopted in which limiting protrusions 120 are provided on both sides of the first punching sheet group 160 and the third punching sheet group 180 to limit the position of the permanent magnet 300. Compared to the solution in the related art in which the limiting protrusions 120 extend from one end to the other along the axial direction of the sector 100, the solution of this embodiment can effectively reduce magnetic flux leakage and improve the performance of the motor.

[0055] It should be noted that modifying the shape of the limiting protrusion 120 can easily lead to increased motor vibration, unstable operation, and increased noise. Since there are fourteen fan-shaped portions 100, i.e., the number of fan-shaped portions 100 is large and the distribution is relatively uniform, the solution with fourteen fan-shaped portions 100 produces lower noise compared to a solution with fewer fan-shaped portions 100. Furthermore, the increased noise level after modifying the shape of the limiting protrusion 120 is also within an acceptable range. Therefore, the solution of this embodiment can improve the overall performance of the motor.

[0056] Reference Figure 6 As shown, in an embodiment of the present invention, along the circumference of the rotor assembly 1000, the maximum protrusion distance of the limiting protrusion 120 is s, which satisfies: 1mm≤s≤2mm. For example, the value of s can be 1mm, 1.1mm, 1.5mm, 1.8mm, or 2mm. When s is less than 1mm, the protrusion distance of the limiting protrusion 120 is small, the strength is low, and the reliability is poor, making it difficult to play the role of limiting the permanent magnet 300 from being separated from the mounting slot 110. When s is greater than 2mm, the protrusion distance of the limiting protrusion 120 is large. Although the strength increases, the leakage flux will also increase, resulting in a decrease in magnetic flux. Therefore, by rationally designing the value of s to be between 1mm and 2mm, it is possible to ensure the strength of the limiting protrusion 120 while reducing the leakage flux and improving the efficiency of the motor.

[0057] Reference Figure 1As shown, in an embodiment of the present invention, the rotor assembly 1000 further includes a plastic overmolding portion 400, which covers the permanent magnet 300 and the sector portion 100. The use of plastic overmolding improves the stability and reliability of the connection between the permanent magnet 300 and the sector portion 100, effectively preventing the permanent magnet 300 from detaching from the mounting slot 110 along the axial direction of the motor, reducing the complexity of assembling the rotor assembly 1000, and improving the insulation performance of the motor, effectively preventing electrical corrosion. The rotor assembly 1000 after plastic overmolding has higher chemical resistance and water resistance, and can maintain good performance and a longer service life even in harsh environments.

[0058] The motor of one embodiment of the present invention comprises the rotor assembly 1000 of the above embodiment. The motor of the present invention adopts the rotor assembly 1000 of the above embodiment, and is arranged by setting a plurality of fan-shaped portions 100 at intervals along the circumference of the rotor assembly 1000. The shaft sleeve 200 is located in the space formed by the plurality of fan-shaped portions 100, and a plurality of permanent magnets 300 are installed in the mounting groove 110 between adjacent fan-shaped portions 100 in a one-to-one correspondence. Among them, one end of the permanent magnet 300 facing the axis of rotation protrudes from the one end of the fan-shaped portion 100 facing the axis of rotation, and abuts against the shaft sleeve 200. Therefore, there is no need to use the fan-shaped portion 100 to limit the position of one end of the permanent magnet 300 facing the axis of rotation, which can reduce the leakage flux caused by setting the limiting structure. At the same time, since one end of the permanent magnet 300 protrudes from the sector-shaped portion 100, the length of the permanent magnet 300 in the radial direction is longer, and the diameter D2 of the maximum inscribed circle of multiple permanent magnets 300 is limited to the range of D1+2*t to D1+2*t+6mm, ensuring that the distance between the permanent magnet 300 and the annular portion 220 is close enough, which can increase the volume of the permanent magnet 300, increase the magnetic flux density, increase the output power of the motor, increase the back electromotive force, and improve the performance of the motor.

[0059] 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 described in detail here.

[0060] The household appliance of one embodiment of the present invention can be an air conditioner, a refrigerator, a dehumidifier, an electric fan, etc., and the household appliance includes the motor of the above embodiment. The household appliance of the present invention embodiment adopts the motor of the above embodiment, the rotor assembly 1000 of the motor is arranged by arranging multiple fan-shaped portions 100 along the circumferential interval of the rotor assembly 1000, the sleeve 200 is located in the space formed by the multiple fan-shaped portions 100, and the multiple permanent magnets 300 are installed in the mounting groove 110 between the adjacent fan-shaped portions 100 in a one-to-one correspondence. Wherein, one end of the permanent magnet 300 protrudes from one end of the fan-shaped portion 100 towards the axis of rotation, and abuts against the sleeve 200. Therefore, it is not necessary to utilize the fan-shaped portion 100 to limit the position of the permanent magnet 300 towards one end of the axis of rotation, and the magnetic flux leakage caused by the setting of the limiting structure can be reduced. At the same time, since one end of the permanent magnet 300 protrudes from the sector-shaped portion 100, the length of the permanent magnet 300 in the radial direction is longer, and the diameter D2 of the maximum inscribed circle of multiple permanent magnets 300 is limited to the range of D1+2*t to D1+2*t+6mm, ensuring that the distance between the permanent magnet 300 and the annular portion 220 is close enough, which can increase the volume of the permanent magnet 300, increase the magnetic flux density, increase the output power of the motor, increase the back electromotive force, and improve the performance of the motor.

[0061] Since the household appliance 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.

[0062] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A rotor assembly, characterized in that: include: A plurality of sector-shaped portions are arranged at intervals along the circumferential direction of the rotation axis of the rotor assembly, with mounting grooves formed between adjacent sector-shaped portions; A shaft sleeve is arranged in a space enclosed by the plurality of sector-shaped portions and is spaced apart from the sector-shaped portions; A plurality of permanent magnets are mounted in the plurality of mounting slots in a one-to-one correspondence, wherein one end of the permanent magnet facing the rotation axis protrudes from one end of the sector portion facing the rotation axis, and the permanent magnets abut against the outer wall of the sleeve; The sleeve is provided with an inner hole for the rotating shaft to pass through, the maximum inner diameter of the inner hole is D1, the minimum thickness of the sleeve is t, the diameter of the maximum inscribed circle inside the plurality of permanent magnets is D2, and the condition: D1+2*t≤D2≤D1+2*t+6mm is satisfied.

2. The rotor assembly according to claim 1, wherein: The sleeve includes an annular portion and a plurality of support ribs. The plurality of support ribs are provided on the outer side wall of the annular portion and are spaced apart along the circumference of the annular portion. The plurality of support ribs and the plurality of permanent magnets are in one-to-one contact with each other.

3. The rotor assembly according to claim 1, wherein: Along the radial direction of the rotor assembly, the maximum length of the permanent magnet is L, and along the circumferential direction of the rotor assembly, the maximum width of the permanent magnet is W, satisfying: 1.5≤L / W≤3.

5.

4. The rotor assembly according to claim 1, wherein: One end of the sector away from the rotation axis includes a first arc surface, the center of the first arc surface coincides with the rotation axis, and the central angle corresponding to the first arc surface is θ, which satisfies: 3°≤θ≤15°.

5. The rotor assembly according to claim 4, characterized in that: One end of the sector portion away from the rotation axis further includes a second arc surface inscribed in the first arc surface, and a radius of the second arc surface is smaller than a radius of the first arc surface.

6. The rotor assembly according to claim 5, characterized in that: The radius of the second arc surface is R, which satisfies: 1.5 mm ≤ R ≤ 10 mm.

7. The rotor assembly according to claim 1, wherein: The number of the sector-shaped portions and the number of the permanent magnets are both fourteen, or the number of the sector-shaped portions and the number of the permanent magnets are both ten.

8. The rotor assembly according to claim 1, wherein: A limiting protrusion is provided on at least one side of one end of the sector 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.

9. The rotor assembly according to claim 8, wherein: The number of the sector-shaped portions and the permanent magnets is fourteen. The sector-shaped portion includes a first punching sheet group, a second punching sheet group and a third punching sheet group. The first punching sheet group and the third punching sheet group are respectively connected to the two ends of the second punching sheet group along the axial direction of the rotor assembly. The first punching sheet group and the third punching sheet group are provided with limiting protrusions on both sides of one end away from the rotation axis. The sector-shaped portion forms a notch between the first punching sheet group and the third punching sheet group.

10. The rotor assembly according to claim 8, wherein: Along the circumference of the rotor assembly, the maximum protruding distance of the limiting protrusion is s, which satisfies: 1mm≤s≤2mm.

11. The motor is characterized by: Comprising a rotor assembly according to any one of claims 1 to 10.

12. A household appliance, characterized in that Including the motor according to claim 11.

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