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 plurality of fan-shaped parts and a plurality of permanent magnets, the plurality of fan-shaped parts are arranged around the rotating axis at intervals, and the plurality of permanent magnets are arranged in the mounting grooves between the two adjacent fan-shaped parts in a one-to-one correspondence mode. A limiting part is arranged at the end, away from the rotating axis, of the fan-shaped part, the first inclined face of the limiting part abuts against the second inclined face of the permanent magnet in a matched mode, so that the contact area between the permanent magnet and the limiting part is increased, and the permanent magnet limiting stability of the limiting part is improved. Therefore, the protruding distance of the limiting part can be reduced, and the ratio of the maximum width of the limiting part protruding out of the fan-shaped part to the maximum width of the permanent magnet is within the range of 0.05-0.08. The width of the limiting part protruding out of the fan-shaped part is small, magnetic leakage is reduced, the power density of the motor is improved, and the cost of the motor is reduced. Therefore, the magnetic leakage of the rotor assembly is reduced, and the limiting stability of the permanent magnet can be ensured.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a rotor assembly, a motor, and a household appliance. Background Technology

[0002] The rotor assembly of a permanent magnet motor has multiple sector sections and multiple permanent magnets, with mounting slots formed between the sector sections for mounting the permanent magnets. To prevent the permanent magnets from detaching radially from the mounting slots, a limiting protrusion is provided at the radially outer end of the mounting slot. The limiting protrusion abuts against the permanent magnet to restrict its position. However, providing the limiting protrusion increases the leakage flux of the rotor assembly; the longer the protrusion length, the greater the leakage flux. But shortening the limiting length to reduce leakage flux leads to decreased limiting stability. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a rotor assembly that can reduce magnetic leakage while ensuring the stability of the permanent magnet's positioning.

[0004] This utility model also proposes a motor and a household appliance having the above-mentioned rotor assembly.

[0005] A rotor assembly according to a first aspect of the present invention includes: an annular inner core having a shaft hole; a plurality of sector-shaped portions spaced apart around the annular inner core, with mounting grooves formed between adjacent sector-shaped portions; at least one side of the end of each sector-shaped portion away from the rotation axis of the rotor assembly has a limiting portion, and the limiting portion has a first inclined surface on the side facing the mounting groove; a plurality of permanent magnets, the same number as the sector-shaped portions, each of the permanent magnets being disposed one-to-one in the mounting groove; each permanent magnet includes a first magnetic part and a second magnetic part, the first magnetic part being connected to the second magnetic part. The first magnetic part has one end facing away from the rotation axis. The width of the first magnetic part gradually increases in the direction close to the rotation axis. The first magnetic part has a second inclined surface along its width direction and facing the first inclined surface. The second inclined surface and the first inclined surface abut against each other. The plastic-coated part, at least part of which is filled between the annular inner core, the sector part, and the permanent magnet, is also present. The maximum width of the limiting part protruding from the side wall of the sector part along the circumference of the rotor assembly is W1, and the maximum width of the permanent magnet is W2, satisfying: 0.05≤W1 / W2≤0.08.

[0006] The rotor assembly according to the embodiments of the present invention has at least the following beneficial effects:

[0007] Multiple sector-shaped sections are spaced apart around an inner ring core. The shaft hole of the inner ring core is used for the motor's rotating shaft to pass through. Multiple permanent magnets are correspondingly arranged in the mounting grooves between adjacent sector-shaped sections. At least part of the plastic coating fills the space between the inner ring core, sector-shaped sections, and permanent magnets. The plastic coating provides insulation, reducing the risk of short circuits and leakage. To prevent the permanent magnets from detaching radially from the mounting grooves, a limiting section is provided at the end of the sector-shaped section away from the rotation axis. The limiting section has a first inclined surface, which abuts against a second inclined surface on the permanent magnet, increasing the contact area between the permanent magnet and the limiting section, thereby improving the stability of the limiting section in limiting the permanent magnet. Therefore, the protrusion distance of the limiting section can be reduced, so that the ratio of the maximum width of the limiting section protruding from the sector-shaped section to the maximum width of the permanent magnet is in the range of 0.05 to 0.08. The smaller width of the limiting section protruding from the sidewall of the sector-shaped section reduces magnetic leakage, increases the power density of the motor, and reduces the cost of the motor. Therefore, while reducing the leakage flux of the rotor assembly, it also ensures the stability of the permanent magnet's positioning.

[0008] According to some embodiments of this utility model, the included angle between the second inclined surface and the end face of the permanent magnet facing away from the rotation axis is α, which satisfies: 100°≤α≤135°.

[0009] According to some embodiments of the present invention, the limiting portion is provided on both sides of the end of the fan-shaped portion away from the rotation axis.

[0010] According to some embodiments of the present invention, the mounting groove includes an outer groove section and a main groove section that are radially connected along the rotor assembly. The outer groove section is located on the side of the main groove section away from the rotation axis. The sidewall of the outer groove section is the first inclined surface. The width of the outer groove section gradually increases along the direction close to the rotation axis. The first magnetic part is located in the outer groove section, and the second magnetic part is located in the main groove section.

[0011] According to some embodiments of the present invention, the mounting groove further includes an inner groove section communicating with the main groove section. The inner groove section is located on the side of the main groove section near the rotation axis. The permanent magnet further includes an end connected to the second magnetic part near the rotation axis. Along the direction near the rotation axis, the width of the inner groove section gradually decreases, the width of the third magnetic part gradually decreases, and the third magnetic part is located inside the inner groove section.

[0012] According to some embodiments of the present invention, the inner groove segment has a third inclined surface at both ends of the rotor assembly along the circumference. The two third inclined surfaces of the same inner groove segment are symmetrically arranged along the radial center line of the inner groove segment. The permanent magnet has a fourth inclined surface on both sides of one end facing the rotation axis. The fourth inclined surface and the corresponding third inclined surface abut against each other.

[0013] According to some embodiments of the present invention, the annular inner core and all of the sector portions are spaced apart; or, some of the sector portions are connected to the annular inner core via connecting sections.

[0014] According to some embodiments of the present invention, the permanent magnet protrudes from the sector along the axial direction of the rotor assembly, the length of the permanent magnet along the axial direction is H1, and the length of the sector along the axial direction is H2, satisfying: 1≤H1 / H2≤1.4.

[0015] The motor according to a second aspect of the present invention includes the rotor assembly described in the above embodiments.

[0016] The motor according to the embodiments of the present invention has at least the following beneficial effects:

[0017] By employing the rotor assembly of the first aspect embodiment, the rotor assembly is provided with multiple sector-shaped portions spaced around an annular inner core. The shaft hole of the annular inner core is used for the motor's rotating shaft to pass through. Multiple permanent magnets are correspondingly disposed in mounting slots between adjacent sector-shaped portions. At least a portion of the plastic coating fills the space between the annular inner core, the sector-shaped portions, and the permanent magnets. The plastic coating provides insulation, reducing the risk of short circuits and leakage. To prevent the permanent magnets from radially detaching from the mounting slots, a limiting portion is provided at the end of the sector-shaped portion away from the rotation axis. The limiting portion has a first inclined surface, which abuts against a second inclined surface on the permanent magnet, increasing the contact area between the permanent magnet and the limiting portion, thereby improving the stability of the limiting portion in limiting the permanent magnet. Therefore, the protrusion distance of the limiting portion can be reduced, making the ratio of the maximum width of the limiting portion protruding from the sector-shaped portion to the maximum width of the permanent magnet within the range of 0.05 to 0.08. The smaller width of the limiting portion protruding from the sidewall of the sector-shaped portion reduces magnetic leakage, increases the power density of the motor, and reduces the cost of the motor. Therefore, while reducing the leakage flux of the rotor assembly, it also ensures the stability of the permanent magnet's positioning.

[0018] The household appliance according to a third aspect of the present invention includes the motor described in the above embodiments.

[0019] The household appliance according to the embodiments of this utility model has at least the following beneficial effects:

[0020] In the motor employing the second aspect embodiment, the rotor assembly of the motor is provided with multiple sector-shaped sections spaced apart around an annular inner core. The shaft hole of the annular inner core is used for the motor's rotating shaft to pass through. Multiple permanent magnets are correspondingly positioned in mounting slots between adjacent sector-shaped sections. At least a portion of the plastic coating fills the space between the annular inner core, the sector-shaped sections, and the permanent magnets. The plastic coating provides insulation, reducing the risk of short circuits and leakage. To prevent the permanent magnets from radially detaching from the mounting slots, a limiting portion is provided at the end of the sector-shaped section away from the rotation axis. The limiting portion has a first inclined surface, which abuts against a second inclined surface on the permanent magnet, increasing the contact area between the permanent magnet and the limiting portion, thereby improving the stability of the limiting portion in limiting the permanent magnet. Therefore, the protrusion distance of the limiting portion can be reduced, making the ratio of the maximum width of the limiting portion protruding from the sector-shaped section to the maximum width of the permanent magnet within the range of 0.05 to 0.08. The smaller width of the limiting portion protruding from the sidewall of the sector-shaped section reduces magnetic leakage, increases the power density of the motor, and reduces the cost of the motor. Therefore, while reducing the leakage flux of the rotor assembly, it also ensures the stability of the permanent magnet's positioning.

[0021] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0023] Figure 1 This is a schematic diagram of the rotor assembly according to one embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of multiple sector-shaped parts according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the fan-shaped part and the permanent magnet in one embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of the structure of a permanent magnet according to an embodiment of the present invention;

[0027] Figure 5 This is a side view of a rotor assembly according to an embodiment of the present invention;

[0028] Figure 6 This is a schematic diagram of the rotor assembly according to another embodiment of the present invention.

[0029] Figure label:

[0030] Rotor assembly 1000;

[0031] Sector-shaped portion 100; mounting groove 110; outer groove section 111; main groove section 112; inner groove section 113; third inclined surface 114; limiting portion 120; first inclined surface 121;

[0032] Permanent magnet 200; second inclined surface 210; fourth inclined surface 220; first magnetic part 230; second magnetic part 240; third magnetic part 250;

[0033] Annular inner iron core 300; connecting section 310; shaft hole 320. Detailed Implementation

[0034] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying 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 with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0035] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0036] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, 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 number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0037] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0038] Reference Figure 1 and Figure 2As shown, a rotor assembly 1000 according to one embodiment of the present invention can be used in a permanent magnet motor. The rotor assembly 1000 of this embodiment includes an annular inner core 300, sector-shaped portions 100, permanent magnets 200, and a plastic-coated portion. Multiple sector-shaped portions 100 and permanent magnets 200 are provided, and the number of sector-shaped portions 100 and permanent magnets 200 is the same. For example, the number of sector-shaped portions 100 and permanent magnets 200 is fourteen, twelve, ten, etc. Multiple sector-shaped portions 100 are spaced apart around the annular inner core 300, for example, the multiple sector-shaped portions 100 are evenly spaced. The annular inner core 300 has a shaft hole 320 for the motor shaft to pass through. A mounting groove 110 is formed between adjacent sector-shaped portions 100 for mounting the permanent magnets 200. (Refer to...) Figure 2 and Figure 3 As shown, the end of the sector portion 100 away from the rotation axis of the rotor assembly 1000 is called the outer end, and the end close to the rotation axis is called the inner end. At least one side of the outer end of the sector portion 100 is provided with a limiting portion 120. The limiting portion 120 has a first inclined surface 121 on the side facing the mounting groove 110. The first inclined surface 121 is inclined towards the opposite sector portion 100.

[0039] Reference Figure 1 and Figure 2 As shown, multiple permanent magnets 200 are correspondingly arranged in the mounting grooves 110, meaning that one permanent magnet 200 is installed in each mounting groove. At least part of the plastic coating fills the space between the annular inner core 300, the sector-shaped portion 100, and the permanent magnet 200. The plastic coating has an insulating function, reducing the risk of short circuits and leakage in the rotor assembly 1000. The permanent magnet 200 has a second inclined surface 210 on the side facing the first inclined surface 121, and the permanent magnet 200 includes a first magnetic part 230 and a second magnetic part 240. The first magnetic part 230 is connected to the end of the second magnetic part 240 away from the rotation axis. The width of the first magnetic part 230 gradually increases in the direction close to the rotation axis. The first magnetic part 230 has a second inclined surface 210 on the side facing the first inclined surface 121 along its width direction. The second inclined surface 210 and the first inclined surface 121 abut against each other. For example, the second inclined surface 210 is formed between the radial end face and the circumferential side face of the permanent magnet 200, and the width of the second magnetic part 240 remains unchanged in the direction close to the axis of rotation.

[0040] In this configuration, along the circumference of the rotor assembly 1000, the maximum width of the limiting portion 120 protruding from the side wall of the fan-shaped portion 100 is W1, and the maximum width of the permanent magnet 200 is W2, satisfying the condition: 0.05 ≤ W1 / W2 ≤ 0.08. For example, the value of W1 / W2 can be 0.05, 0.06, 0.07, 0.08, etc. It should be noted that, referring to... Figure 3As shown, the maximum width of the limiting portion 120 protruding from the sector portion 100 refers to the maximum distance from the limiting portion 120 to the side S1 of the sector portion 100 along a direction perpendicular to the side S1 of the sector portion 100. The widths of the first magnetic portion 230 and the second magnetic portion 240 both refer to the width along the circumferential direction of the rotor assembly 1000.

[0041] Understandably, the ratio of the maximum width W1 of the limiting part 120 protruding from the fan-shaped part 100 to the maximum width W2 of the permanent magnet 200 is in the range of 0.05 to 0.08. Normally, the maximum width of the permanent magnet 200 remains constant. When the ratio of W1 / W2 is greater than 0.08, meaning the maximum width of the limiting part 120 protruding from the fan-shaped part 100 is large, the magnetic field of the permanent magnet 200 is difficult to form an effective loop at the limiting part 120, resulting in increased magnetic leakage. When the ratio of W1 / W2 is less than 0.05, the maximum width of the limiting part 120 protruding from the fan-shaped part 100 is small, leading to a decrease in the contact area between the first inclined surface 121 and the second inclined surface 210, thus reducing the limiting ability of the permanent magnet 200.

[0042] It is understandable that by adopting the above-described scheme, the first inclined surface 121 and the second inclined surface 210 on the permanent magnet 200 abut against each other, which increases the contact area between the permanent magnet 200 and the limiting part 120, thereby improving the stability of the limiting part 120 in limiting the permanent magnet 200. Due to the improved stability in limiting the permanent magnet 200, the maximum width of the limiting part 120 protruding from the fan-shaped part 100 can be reduced. It should be noted that in related technologies, the protrusion width of the protrusion used to limit the permanent magnet 200 is typically one-tenth of the maximum width of the permanent magnet 200. However, using the scheme of this application, the ratio of the maximum width of the limiting part 120 protruding from the fan-shaped part 100 to the maximum width of the permanent magnet 200 is in the range of 0.05 to 0.08, which is smaller than the maximum width of the protrusion in related technologies. Therefore, the width of the limiting part 120 protruding from the fan-shaped part 100 in this embodiment is smaller, which can reduce magnetic leakage, increase motor power density, and reduce motor cost. Therefore, while reducing magnetic leakage in the rotor assembly 1000 of this embodiment, it also ensures the stability of the permanent magnet 200.

[0043] Reference Figure 4As shown in the embodiment of this utility model, the included angle α between the second inclined surface 210 and the end face of the permanent magnet 200 facing away from the rotation axis satisfies: 100°≤α≤135°. For example, the value of α can be 100°, 110°, 115°, 120°, 125°, 135°, etc. It should be noted that since the second inclined surface 210 and the first inclined surface 121 abut against each other, the inclination angle of the second inclined surface 210 is parallel to and the same as that of the first inclined surface 121. When the included angle α between the second inclined surface 210 and the end face of the permanent magnet 200 facing away from the rotation axis is less than 100°, the maximum width of the limiting part 120 protruding from the fan-shaped part 100 is reduced, and the limiting ability of the permanent magnet 200 is reduced. When the included angle α between the second inclined surface 210 and the end face of the permanent magnet 200 facing away from the rotation axis is greater than 135°, the maximum width of the limiting part 120 protruding from the fan-shaped part 100 increases, leading to increased magnetic leakage and reduced motor performance. Therefore, by reasonably designing the included angle α within the range of 100° to 135°, it is possible to ensure stable restriction of the permanent magnet 200 from disengaging from the mounting groove 110 while also reducing magnetic leakage.

[0044] Reference Figure 3 As shown in the embodiment of this utility model, limiting portions 120 are respectively provided on both sides of the end of the fan-shaped portion 100 away from the rotation axis, and the permanent magnet 200 is provided on both sides along the circumferential direction with second inclined surfaces 210, thereby abutting and cooperating with the first inclined surfaces 121 of the limiting portions 120 on both sides. By providing limiting portions 120 on both sides of the fan-shaped portion 100, the limiting stability and reliability of the permanent magnet 200 can be improved, effectively preventing the permanent magnet 200 from detaching from the mounting groove 110 radially. It should be noted that, in another embodiment, the limiting portion 120 is provided only on one side of the end of the fan-shaped portion 100 away from the rotation axis, and the limiting portion 120 is provided on the other side, which can also limit the position of the permanent magnet 200 and reduce magnetic leakage.

[0045] Reference Figure 2As shown, in this embodiment of the present invention, the mounting groove 110 includes an outer groove section 111 and a main groove section 112 that are radially connected along the rotor assembly 1000. The outer groove section 111 is located on the side of the main groove section 112 opposite to the rotation axis. The sidewall of the outer groove section 111 is a first inclined surface 121. Along the direction close to the rotation axis, the width of the outer groove section 111 gradually increases. The first magnetic part 230 is located inside the outer groove section 111, and the second magnetic part 240 is located inside the main groove section 112. It should be noted that the width of the outer groove section 111 and the width of the main groove section 112 both refer to the circumferential width along the rotor assembly 1000. It can be understood that the width of the outer groove section 111 gradually decreases along the direction opposite to the rotation axis. Therefore, when one end of the permanent magnet 200 is disposed in the outer groove section 111, it can effectively limit the permanent magnet 200 from detaching radially from the mounting groove 110. In particular, the width of the main groove section 112 can remain unchanged along the direction close to the rotation axis, which facilitates the production and manufacturing of the permanent magnet 200 while ensuring that the size of the permanent magnet 200 meets the requirements.

[0046] Reference Figure 2 As shown, in this embodiment of the present invention, the mounting groove 110 further includes an inner groove section 113 communicating with the main groove section 112. The inner groove section 113 is located on the side of the main groove section 112 closer to the rotation axis. Therefore, the outer groove section 111, the main groove section 112, and the inner groove section 113 are connected sequentially along the radial direction of the rotor assembly 1000. The permanent magnet 200 also includes a third magnetic part 250 connected to the end of the second magnetic part 240 closer to the rotation axis. Along the direction closer to the rotation axis, the width of the inner groove section 113 gradually decreases, and at the same time, the width of the third magnetic part 250 gradually decreases. The third magnetic part 250 is located inside the inner groove section 113 and abuts against the inner groove section 113. It should be noted that the width of the main groove section 112 refers to the width along the circumference of the rotor assembly 1000, and the width of the third magnetic part 250 refers to the width along the circumference of the rotor assembly 1000. It is understandable that by setting the width of the inner groove section 113 and the third magnetic part 250 to gradually decrease, the permanent magnet 200 can be effectively restricted from detaching from the mounting groove 110 in the radial direction.

[0047] Reference Figure 2 , Figure 3 and Figure 4As shown in the embodiment of this utility model, the inner groove segment 113 has three third inclined surfaces 114 at both ends along the circumference of the rotor assembly 1000. The two third inclined surfaces 114 of the same inner groove segment 113 are symmetrically arranged along the radial center line of the inner groove segment 113, which is beneficial to the production and manufacturing of the sector portion 100. The radial center line of the inner groove segment 113 refers to the line connecting the centers of the two ends of the inner groove segment 113 along the radial direction. The permanent magnet 200 has four fourth inclined surfaces 220 on both sides of the end facing the rotation axis. The fourth inclined surfaces 220 and the corresponding third inclined surfaces 114 abut against each other, which can increase the stability of the mounting groove 110 in limiting the permanent magnet 200. At the same time, it is not necessary to set a protrusion to limit the position of the permanent magnet 200 at the end of the sector portion 100 facing the rotation axis, thereby reducing the leakage flux of the rotor assembly 1000, increasing the power density of the motor, and reducing the cost of the motor.

[0048] Reference Figure 3 and Figure 4 As shown in the embodiment of this utility model, the included angle β between the fourth inclined surface 220 and the end face of the permanent magnet 200 near the rotation axis satisfies: 100°≤β≤135°. For example, the value of β can be 100°, 110°, 115°, 120°, 125°, 135°, etc. It should be noted that the fourth inclined surface 220 and the third inclined surface 114 abut against each other, so the inclination angle of the fourth inclined surface 220 is parallel to and the same as that of the third inclined surface 114. When the included angle β between the fourth inclined surface 220 and the end face of the permanent magnet 200 away from the rotation axis is less than 100°, the limiting ability of the inner groove section 113 on the permanent magnet 200 is reduced, which can easily cause the permanent magnet 200 to detach from the mounting groove 110. When the included angle β between the fourth inclined plane 220 and the end face of the permanent magnet 200 facing away from the rotation axis is greater than 135°, the volume of the permanent magnet 200 decreases, the magnetic flux decreases, and the performance of the motor deteriorates. Therefore, by reasonably designing the included angle β to be within the range of 100° to 135°, it is possible to ensure that the permanent magnet 200 is stably restricted from detaching from the mounting slot 110 while also ensuring that the magnetic flux is within a suitable range.

[0049] Reference Figure 1As shown in the embodiment of this utility model, the rotor assembly 1000 further includes an annular inner core 300 and a plastic-coated portion. The annular inner core 300 is located within the space formed by multiple sector portions 100. The annular inner core 300 is used to connect with the motor shaft. The plastic-coated portion, sector portions 100, permanent magnets 200, and annular inner core 300 are integrally injection molded. It can be understood that the plastic-coated portion is used to encapsulate the sector portions 100, permanent magnets 200, and annular inner core 300. During the molding process, the sector-shaped part 100, permanent magnet 200, annular inner iron core 300, and shaft are positioned in the mold. Liquid molding material is then poured into the mold, ensuring it covers the sector-shaped part 100, permanent magnet 200, annular inner iron core 300, and shaft. After the molding material solidifies, it forms a plastic coating, thus restricting the relative positions of the sector-shaped part 100, permanent magnet 200, annular inner iron core 300, and shaft. The molding material can be a thermosetting plastic, such as unsaturated polyester resin and epoxy resin. It can also be BMC (glass fiber reinforced thermoplastic), a commonly used material in molded motors due to its excellent physical, electrical, and mechanical properties.

[0050] Continue to refer to Figure 1 As shown in the embodiment of this utility model, the annular inner core 300 and all the sector portions 100 are spaced apart. Therefore, a plastic coating is needed to fix the relative position between the annular inner core 300 and the sector portions 100. It is understood that the materials used for the annular inner core 300 and the sector portions 100 are typically magnetically conductive, and the magnetic circuit generated by the permanent magnet 200 can move along the sector portions 100. To avoid direct connection between the annular inner core 300 and the sector portions 100, a spaced-apart arrangement is adopted, effectively reducing the magnetic circuit passing through the annular inner core 300, thereby reducing magnetic leakage and improving motor performance.

[0051] Reference Figure 6As shown, in another embodiment of this utility model, the rotor assembly 1000 further includes a connecting section 310, the two ends of which are respectively connected to the outer wall of the annular inner core 300 and the end of the sector portion 100 facing the rotation axis. Specifically, each sector portion 100 may be connected to the annular inner core 300 via the connecting section 310; or some sector portions 100 may be connected to the annular inner core 300 via the connecting section 310, while other sector portions 100 and the annular inner core 300 may be spaced apart. It is understood that by adopting the above scheme, the relative position between the annular inner core 300 and the sector portions 100 can be determined, improving the stability and reliability of the connection between the sector portions 100 and the annular inner core 300, and reducing the risk of loosening and detachment. For example, the number of connecting segments 310 is half the number of sector sections 100. There are fourteen sector sections 100 and seven connecting segments 310. Every other sector section 100 is connected to the annular inner core 300 through a connecting segment 310. That is, half of the sector sections 100 are connected to the annular inner core 300 through connecting segments 310, while the other half of the sector sections 100 and the annular inner core 300 are spaced apart. This can ensure the stability of the connection between the annular inner core 300 and the sector section 100 while minimizing the impact of magnetic leakage, thereby increasing the power density of the motor and reducing the cost of the motor.

[0052] Reference Figure 5 As shown in the embodiment of this utility model, the permanent magnet 200 protrudes from the sector portion 100 along the axial direction of the rotor assembly 1000. The axial length of the permanent magnet 200 is H1, and the axial length of the sector portion 100 is H2, satisfying the condition: 1 ≤ H1 / H2 ≤ 1.4. For example, the value of H1 / H2 can be 1, 1.1, 1.2, 1.3, 1.4, etc. When the value of H1 / H2 is less than 1, it indicates that the length of the permanent magnet 200 is less than the length of the sector portion 100, which can easily lead to insufficient magnetic flux. When the value of H1 / H2 is greater than 1.4, the length of the permanent magnet 200 is much greater than the length of the sector portion 100, and the excess magnetic flux cannot be utilized, resulting in material waste and an increase in the overall length of the motor. Therefore, by designing the ratio of the length H1 of the permanent magnet 200 to the length H2 of the sector portion 100 to be within the range of 1 to 1.4, the utilization rate of magnetic flux can be improved, thereby improving the performance of the motor.

[0053] One embodiment of the present invention provides a motor comprising the rotor assembly 1000 described in the above embodiments. The motor of this embodiment uses the rotor assembly 1000 described in the above embodiments, with multiple sector-shaped portions 100 spaced apart around a rotation axis, and multiple permanent magnets 200 correspondingly disposed in mounting grooves 110 between adjacent sector-shaped portions 100. To prevent the permanent magnets 200 from radially disengaging from the mounting grooves 110, a limiting portion 120 is provided at the end of each sector-shaped portion 100 away from the rotation axis. The limiting portion 120 has a first inclined surface 121, which abuts against a second inclined surface 210 on the permanent magnet 200, thereby increasing the contact area between the permanent magnet 200 and the limiting portion 120, and thus improving the stability of the limiting portion 120 in limiting the permanent magnet 200. The ratio of the maximum width of the limiting portion 120 protruding from the sector portion 100 to the maximum width of the permanent magnet 200 is within the range of 0.05 to 0.08. The relatively small width of the limiting portion 120 protruding from the sector portion 100 reduces magnetic leakage, increases motor power density, and lowers motor cost. Therefore, by adopting the above solution, the magnetic leakage of the rotor assembly 1000 is reduced while ensuring the stability of the limiting position of the permanent magnet 200.

[0054] Since the motor adopts all the technical solutions of the rotor assembly 1000 of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be repeated here.

[0055] This utility model discloses a household appliance according to one embodiment, including the motor described in the above embodiments. The household appliance can be an air conditioner, refrigerator, washing machine, electric fan, dehumidifier, etc. In this embodiment, the motor is used. The rotor assembly 1000 of the motor has multiple sector-shaped portions 100 spaced apart around a rotation axis, and multiple permanent magnets 200 are correspondingly disposed in mounting grooves 110 between adjacent sector-shaped portions 100. To prevent the permanent magnets 200 from radially disengaging from the mounting grooves 110, a limiting portion 120 is provided at the end of each sector-shaped portion 100 away from the rotation axis. The limiting portion 120 has a first inclined surface 121, which abuts against a second inclined surface 210 on the permanent magnet 200. This increases the contact area between the permanent magnet 200 and the limiting portion 120, thereby improving the stability of the limiting portion 120 in limiting the permanent magnet 200. The ratio of the maximum width of the limiting portion 120 protruding from the sector portion 100 to the maximum width of the permanent magnet 200 is within the range of 0.05 to 0.08. The relatively small width of the limiting portion 120 protruding from the sector portion 100 reduces magnetic leakage, increases motor power density, and lowers motor cost. Therefore, by adopting the above solution, the magnetic leakage of the rotor assembly 1000 is reduced while ensuring the stability of the limiting position of the permanent magnet 200.

[0056] Since the household appliance adopts all the technical solutions of the motor in the above embodiments, it has at least all the beneficial effects brought about by the technical solutions in the above embodiments, which will not be repeated here.

[0057] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A rotor assembly characterized by, The rotor assembly comprises: a ring-shaped inner core having an axial hole; a plurality of sector-shaped portions arranged at intervals around the ring-shaped inner core, forming mounting slots between adjacent sector-shaped portions, at least one side of an end of the sector-shaped portion away from the rotation axis of the rotor assembly being provided with a limiting portion, the limiting portion having a first inclined surface on a side facing the mounting slot; a plurality of permanent magnets, the number of the permanent magnets being the same as that of the sector-shaped portions, each of the plurality of permanent magnets being arranged in the mounting slot, the permanent magnet comprising a first magnetic portion and a second magnetic portion, the first magnetic portion being connected to an end of the second magnetic portion away from the rotation axis, the width of the first magnetic portion gradually increasing in a direction close to the rotation axis, the first magnetic portion being provided with a second inclined surface along the width direction of the first magnetic portion and facing a side of the first inclined surface, the second inclined surface and the first inclined surface being in abutment; a plastic-coated portion, at least part of the plastic-coated portion being filled between the ring-shaped inner core and the sector-shaped portion and the permanent magnet; wherein, along the circumferential direction of the rotor assembly, the maximum width of the limiting portion protruding from the side wall of the sector-shaped portion is W1, and the maximum width of the permanent magnet is W2, satisfying 0.05≤W1 / W2≤0.

08.

2. The rotor assembly of claim 1, wherein: The included angle between the second inclined surface and the end surface of the permanent magnet away from the rotation axis is α, satisfying 100°≤α≤135°.

3. The rotor assembly of claim 1, wherein: Both sides of the end of the sector-shaped portion away from the rotation axis are respectively provided with the limiting portion.

4. The rotor assembly of claim 3, wherein: The mounting slot comprises an outer slot segment and a main slot segment in communication along the radial direction of the rotor assembly, the outer slot segment being located on a side of the main slot segment away from the rotation axis, the side wall of the outer slot segment being the first inclined surface, the width of the outer slot segment gradually increasing in a direction close to the rotation axis, the first magnetic portion being located in the outer slot segment, and the second magnetic portion being located in the main slot segment.

5. The rotor assembly of claim 4, wherein: The mounting slot further comprises an inner slot segment in communication with the main slot segment, the inner slot segment being located on a side of the main slot segment close to the rotation axis, the permanent magnet further comprising a third magnetic portion connected to an end of the second magnetic portion close to the rotation axis, the width of the inner slot segment gradually decreasing in a direction close to the rotation axis, the width of the third magnetic portion gradually decreasing, and the third magnetic portion being located in the inner slot segment.

6. The rotor assembly of claim 5, wherein: Both ends of the inner slot segment along the circumferential direction of the rotor assembly are respectively provided with a third inclined surface, the two third inclined surfaces of the same inner slot segment being symmetrically arranged along the radial center line of the inner slot segment, both sides of an end of the permanent magnet facing the rotation axis are respectively provided with a fourth inclined surface, and the fourth inclined surface and the corresponding third inclined surface are in abutment.

7. The rotor assembly of claim 1, wherein: The ring-shaped inner core and all the sector-shaped portions are arranged at intervals; or, part of the sector-shaped portions are connected to the ring-shaped inner core through connecting segments.

8. The rotor assembly of claim 1, wherein: The permanent magnet protrudes from the sector-shaped portion along the axial direction of the rotor assembly, the length of the permanent magnet along the axial direction is H1, the length of the sector-shaped portion along the axial direction is H2, satisfying 1≤H1 / H2≤1.

4.

9. An electric machine characterized by: The electric machine comprises the rotor assembly according to any one of claims 1 to 8.

10. Household appliance, characterized in that: The electric machine comprises the rotor assembly according to claim 9.

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