Rotor assembly, motor and household appliance

Abstract

The utility model discloses a rotor assembly, a motor and a household electrical appliance, and relates to the technical field of motors. The rotor assembly comprises a rotor iron core and permanent magnets, the plurality of permanent magnets are arranged around the rotating axis of the rotor assembly, the first magnetic sections and the second magnetic sections of the permanent magnets are arranged in an included angle and form first mounting grooves, the first iron core blocks of the rotor iron core are arranged in the first mounting grooves, and the outer side surfaces of the first iron core blocks are exposed out of the opening. Therefore, magnetic flux of the first magnetic section and the second magnetic section can enter the first iron core block and then enter an air gap of the motor through the outer side face of the first iron core block, so that the magnetic gathering effect is improved, the air gap magnetic density is increased, the torque density is improved, and the performance of the motor is improved. And the first iron core block is fixedly connected with the permanent magnet in a plastic coating manner, so that structures such as limiting bulges do not need to be arranged, magnetic flux leakage can be effectively reduced, and the working efficiency 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 of the permanent magnet motor includes a plurality of sector-shaped parts and a plurality of permanent magnets. The plurality of sector-shaped parts are arranged around the rotation axis of the permanent magnet motor. An installation groove is formed between adjacent sector-shaped parts, and the permanent magnet is arranged in the installation groove. In order to prevent the permanent magnet from escaping from the installation groove, a limiting protrusion is provided at both ends of the sector-shaped part, thereby limiting the position of the permanent magnet. With the above scheme, although the limiting protrusion can limit the position of the permanent magnet, it will cause the leakage magnetic field at the limiting protrusion to increase, and the working efficiency of the motor will be reduced. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model provides a rotor assembly that can reduce magnetic leakage, increase air gap magnetic density, and improve the working efficiency of the motor.

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

[0005] According to the first aspect of the present invention, the rotor assembly includes: a plurality of permanent magnets arranged around the rotation axis of the rotor assembly, the permanent magnets including a first magnetic segment and a second magnetic segment arranged at an angle to each other, a first mounting groove formed between the first magnetic segment and the second magnetic segment, the first mounting groove having an opening along the radial direction of the rotor assembly, the opening facing a side away from the rotation axis;

[0006] The rotor core includes a plurality of first core blocks, the number of the first core blocks is the same as the number of the permanent magnets, the plurality of first core blocks are correspondingly arranged in the plurality of first mounting grooves, the outer side surfaces of the first core blocks are exposed in the openings, and the first core blocks are fixedly connected to the permanent magnets by plastic coating.

[0007] The rotor assembly according to the embodiment of the utility model has at least the following beneficial effects:

[0008] By arranging a plurality of permanent magnets around the rotation axis of the rotor assembly, the first magnetic segment and the second magnetic segment of the permanent magnet are arranged at an angle to each other and form a first mounting groove, and the first core block of the rotor core is arranged in the first mounting groove, and the outer side surface of the first core block is exposed in the opening. Therefore, the magnetic flux of the first magnetic segment and the second magnetic segment can enter the first core block, and then enter the air gap of the motor through the outer side surface of the first core block, so as to improve the magnetic concentration effect, increase the air gap magnetic density, and increase the torque density, so as to improve the performance of the motor. The first core block is fixedly connected to the permanent magnet by means of plastic coating, so there is no need to set structures such as limit protrusions, which can effectively reduce leakage magnetic flux and further improve the working efficiency of the motor.

[0009] According to some embodiments of the present invention, the permanent magnet further includes a connecting segment, and two ends of the connecting segment are respectively connected to one end of the first magnetic segment and the second magnetic segment close to the rotation axis.

[0010] According to some embodiments of the present invention, among two adjacent permanent magnets, a side surface of the first magnetic segment of one of the permanent magnets abuts against a side surface of the second magnetic segment of the other permanent magnet.

[0011] According to some embodiments of the utility model, a second installation groove is formed between two adjacent permanent magnets, and the rotor core also includes second core blocks having the same number as the permanent magnets. A plurality of the second core blocks are arranged in the corresponding second installation grooves, and along the circumference of the rotor assembly, a plurality of the first core blocks and a plurality of the second core blocks are alternately arranged in sequence.

[0012] According to some embodiments of the present invention, along the circumference of the rotor assembly, the maximum width of the first mounting groove at one end away from the rotation axis is W1, and the minimum width of the first mounting groove at one end close to the rotation axis is W2, satisfying: 1.2≤W1 / W2≤5.

[0013] According to some embodiments of the utility model, one end of the first magnetic segment close to the rotation axis is connected to one end of the second magnetic segment close to the rotation axis, the rotor core includes a main body, a plurality of grooves surrounding the rotation axis are arranged at intervals on the outer edge of the main body, an accommodating groove is formed between the first core block and the inner wall of the groove, and the permanent magnet is arranged in the accommodating groove.

[0014] According to some embodiments of the present invention, the permanent magnet is integrally injection molded in the accommodating groove.

[0015] According to some embodiments of the present invention, along the circumference of the rotor assembly, the maximum width of the end of the first mounting groove away from the rotation axis is W1, and the maximum width between the outer side surface of the first magnetic segment and the outer side surface of the second magnetic segment is W3, satisfying: 0.48≤W1 / W3≤0.85.

[0016] According to some embodiments of the present invention, the outer end surface of the first magnetic segment and / or the outer end surface of the second magnetic segment is a plane.

[0017] According to some embodiments of the utility model, among two adjacent permanent magnets, the first magnetic segment of one of the permanent magnets is abutted against the second magnetic segment of the other permanent magnet, and the outer end surfaces of the first magnetic segment and the second magnetic segment are both planes and are formed with a plastic coating groove, and the plastic coating groove is used to fill the plastic coating material.

[0018] According to some embodiments of the present invention, the outer side surface of the first core block is a first arc surface, the outer side surface of the first magnetic segment is a second arc surface, and the outer side surface of the second magnetic segment is a third arc surface. The radii of the first arc surface, the second arc surface and the third arc surface are the same, and the centers of the circles are all located at the rotation axis.

[0019] The motor according to the second embodiment of the utility model includes the rotor assembly described in the above embodiment.

[0020] The motor according to the embodiment of the utility model has at least the following beneficial effects:

[0021] By adopting the rotor assembly of the first aspect embodiment, the rotor assembly is arranged by arranging a plurality of permanent magnets around the rotation axis of the rotor assembly, the first magnetic segment and the second magnetic segment of the permanent magnet are arranged at an angle to each other and form a first mounting groove, the first core block of the rotor core is arranged in the first mounting groove, and the outer side surface of the first core block is exposed in the opening. Therefore, the magnetic flux of the first magnetic segment and the second magnetic segment can enter the first core block, and then enter the air gap of the motor through the outer side surface of the first core block, so as to improve the magnetic concentration effect, increase the air gap magnetic density, and improve the torque density, so as to improve the performance of the motor. The first core block is fixedly connected to the permanent magnet by means of plastic coating, so there is no need to set structures such as limit protrusions, which can effectively reduce leakage magnetic flux and further improve the working efficiency of the motor.

[0022] A household appliance according to an embodiment of the third aspect of the utility model comprises the motor described in the above embodiment.

[0023] The household appliance according to the embodiment of the utility model has at least the following beneficial effects:

[0024] By adopting the motor of the second aspect embodiment, the rotor assembly of the motor is arranged by arranging a plurality of permanent magnets around the rotation axis of the rotor assembly, the first magnetic segment and the second magnetic segment of the permanent magnet are arranged at an angle to each other and form a first mounting groove, the first core block of the rotor core is arranged in the first mounting groove, and the outer side surface of the first core block is exposed in the opening. Therefore, the magnetic flux of the first magnetic segment and the second magnetic segment can enter the first core block, and then enter the air gap of the motor through the outer side surface of the first core block, so as to improve the magnetic concentration effect, increase the air gap magnetic density, and improve the torque density, so as to improve the performance of the motor. The first core block is fixedly connected to the permanent magnet by means of plastic coating, so there is no need to set structures such as limit protrusions, which can effectively reduce leakage magnetic flux and further improve the working efficiency of the motor.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description, and in part will become apparent from the following description, or will be learned through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 It is a structural schematic diagram of a rotor assembly of the first embodiment of the utility model, wherein a first core block is separated from a first mounting groove;

[0028] Figure 2 is a structural schematic diagram of a rotor assembly of a second embodiment of the utility model, wherein a second core block is separated from a second mounting groove;

[0029] Figure 3 This is a schematic structural diagram of a permanent magnet in one embodiment of the utility model;

[0030] Figure 4 It is a structural schematic diagram of a permanent magnet of another embodiment of the utility model;

[0031] Figure 5 It is a structural schematic diagram of a rotor assembly of a third embodiment of the utility model, wherein one permanent magnet, a first core block and a body are separated, and one permanent magnet is hidden;

[0032] Figure 6 It is a schematic structural diagram of a rotor assembly of a fourth embodiment of the utility model, wherein one permanent magnet, a first core block and a body are separated, and one permanent magnet is hidden;

[0033] Figure 7 It is a structural schematic diagram of a permanent magnet of another embodiment of the utility model;

[0034] Figure 8 yes Figure 1 The enlarged view of point A in the middle;

[0035] Fig. 9 It is a curve relationship diagram of the ratio of W1 / W2 and the per unit value of the back electromotive force in one embodiment of the utility model;

[0036] Fig.10 It is a curve relationship diagram of the ratio of W1 / W3 and the per unit value of the back electromotive force in one embodiment of the utility model.

[0037] Reference numerals:

[0038] Rotor assembly 1000;

[0039] Permanent magnet 100; first magnetic segment 110; second arc surface 111; second magnetic segment 120; third arc surface 121; first mounting groove 130; connecting segment 140; second mounting groove 150; plastic coating groove 160; plastic coating material 170;

[0040] The rotor core 200 ; the first core block 210 ; the first arc surface 211 ; the second core block 220 ; the body 230 ; the receiving groove 231 ; the groove 232 ; and the positioning hole 240 . DETAILED DESCRIPTION

[0041] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0042] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0043] In the description of the present utility model, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0044] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0045] Reference Figure 1 As shown, a rotor assembly 1000 of an embodiment of the utility model can be used in a permanent magnet motor. The rotor assembly 1000 of the embodiment of the utility model includes a permanent magnet 100 and a rotor core 200. The permanent magnet 100 is provided in multiple and is arranged around the rotation axis of the rotor assembly 1000. The permanent magnet 100 includes a first magnetic segment 110 and a second magnetic segment 120. The first magnetic segment 110 and the second magnetic segment 120 are arranged at an angle to each other, so a first mounting groove 130 is formed between the first magnetic segment 110 and the second magnetic segment 120. The first mounting groove 130 is provided with an opening along the radial direction of the rotor assembly 1000, and the opening is arranged toward a side away from the rotation axis. The rotor core 200 includes a first core block 210, the number of the first core blocks 210 is the same as the number of the permanent magnets 100, and the multiple first core blocks 210 are correspondingly provided with multiple first mounting grooves 130, and the outer side surfaces of the first core blocks 210 are exposed in the openings of the first mounting grooves 130. The first core blocks 210 are fixedly connected to the permanent magnets 100 by means of plastic wrapping, thereby preventing the first core blocks 210 from detaching from the first mounting grooves 130.

[0046] It should be noted that Figure 1 The arrow on the permanent magnet 100 indicates the direction of the magnetic flux. The magnetic flux of the first magnetic segment 110 and the second magnetic segment 120 enters the first core block 210, and then enters the air gap of the motor through the outer side of the first core block 210. After the magnetic field of the winding of the stator assembly acts, it then enters the adjacent first core block 210 and returns to the first magnetic segment 110 and the second magnetic segment 120 to form a complete magnetic circuit. It can be understood that by arranging the first magnetic segment 110 and the second magnetic segment 120 on both sides of the first core block 210, the magnetic flux emission area of ​​the permanent magnet 100 is larger than the area of ​​the first core block 210 close to the air gap, which can improve the magnetic field concentration effect of the rotor assembly 1000, increase the air gap magnetic density, increase the torque density, and thus improve the performance of the motor. The first core block 210 is fixedly connected to the permanent magnet 100 by means of plastic coating, so there is no need to set a limit protrusion and other structures, which can effectively reduce leakage magnetic flux and further improve the working efficiency of the motor.

[0047] In the embodiment of the utility model, PBT or BMC material can be used when plastic coating the rotor core 200 and the permanent magnet 100 to fix the relative position between the permanent magnet 100 and the rotor core 200, avoid the rotor core 200 from loosening and falling off, and improve the stability and reliability of the connection. It should be noted that BMC is an unsaturated polyester thermosetting plastic reinforced by glass fiber, which is widely used in the fields of motor plastic sealing. BMC material has high strength, high heat resistance, low shrinkage and good electrical insulation performance. At the same time, it also has good tensile, impact and bending strength to ensure the mechanical properties of the motor. BMC material has high resistivity and breakdown voltage to ensure the electrical insulation performance of the motor; at the same time, it also has a good thermal conductivity coefficient to ensure the heat dissipation effect of the motor; at the same time, it also has a small shrinkage and water absorption, which can ensure the reliability and stability of the motor. PBT is a thermosetting engineering plastic. PBT can be processed by various processing techniques such as injection molding and extrusion molding, and is suitable for the preparation of complex shapes. PBT has good temperature resistance within a certain temperature range and is suitable for medium and low temperature scenarios. It also has high strength and toughness and can withstand certain impact and tensile forces. Therefore, PBT material can also be used for motor packaging.

[0048] Reference Figure 1 As shown, in the embodiment of the utility model, the permanent magnet 100 further includes a connecting section 140, and the two ends of the connecting section 140 are respectively connected to the first magnetic section 110 and one end of the second magnetic section 120 close to the rotation axis. Therefore, the volume of the permanent magnet 100 can be further increased. Since the first magnetic section 110, the second magnetic section 120 and the connecting section 140 can all provide magnetic flux, the magnetic flux of the permanent magnet 100 can be increased. At the same time, the connecting section 140 can further increase the magnetic flux emission area of ​​the permanent magnet 100, so as to further improve the magnetic field concentration effect of the rotor assembly 1000, further increase the air gap magnetic density, and thus improve the performance of the motor.

[0049] Reference Figure 1 As shown, in the first embodiment of the utility model, two adjacent permanent magnets 100 are in contact with each other. For example, in two adjacent permanent magnets 100, the side of the first magnetic segment 110 of one permanent magnet 100 is in contact with the side of the second magnetic segment 120 of the other permanent magnet 100. With this solution, more permanent magnets 100 can be provided, thereby effectively increasing the volume of the permanent magnets 100; and every two first magnetic segments 110 and two second magnetic segments 120 simultaneously conduct the magnetic circuit through a first core block 210, the magnetic density is increased, the magnetic load of the motor can be increased, the speed of the motor is reduced, and the output torque is increased, which is suitable for some heavy-load occasions.

[0050] Reference Figure 2As shown, in the second embodiment of the utility model, a second installation groove 150 is formed between two adjacent permanent magnets 100, and the rotor core 200 also includes a second core block 220, the number of the second core blocks 220 is the same as the number of the permanent magnets 100, and a plurality of second core blocks 220 are arranged in the corresponding second installation groove 150. Along the circumference of the rotor assembly 1000, a plurality of first core blocks 210 and a plurality of second core blocks 220 are alternately arranged in sequence. Among them, the size and shape of the second core block 220 are the same as those of the first core block 210; or, the shape of the second core block 220 is different from that of the first core block 210, and one end of the second core block 220 close to the rotation axis extends to a position flush with one end of the permanent magnet 100 close to the rotation axis. With this solution, the number of permanent magnets 100 is less than that of the first embodiment, for example, the number of permanent magnets 100 in the first embodiment is ten, and the number of permanent magnets 100 in the second embodiment is five. It can be understood that as the number of permanent magnets 100 decreases, the magnetic load decreases, the rotation speed of the motor increases, and the output torque decreases, so it is suitable for motors that often run in a light-load state.

[0051] Reference Figure 1 and Figure 2 As shown, in the embodiment of the utility model, by designing the rotor core 200 as a plurality of first core blocks 210, or designing as a plurality of first core blocks 210 and a plurality of second core blocks 220, it is convenient to punch out corresponding punching sheets on a whole plate, and after overlapping, the plurality of punching sheets respectively constitute the first core block 210 and the second core block 220. Compared with the solution of punching out a complete rotor core 200 as a whole, the solution of using the first core block 210 and the second core block 220 can improve the utilization rate of the plate and reduce the production cost.

[0052] Reference Figure 3 As shown, in the embodiment of the present invention, based on the solution of the first embodiment or the second embodiment, along the circumference of the rotor assembly 1000, the maximum width of the end of the first installation slot 130 away from the rotation axis is W1, and the minimum width of the end of the first installation slot 130 close to the rotation axis is W2, which satisfies: 1.2≤W1 / W2≤5. For example, the value of W1 / W2 can be 1.2, 1.8, 2, 2.5, 3, 4, 4.5, 5, etc. Fig. 9 As shown, Fig. 9The horizontal axis represents the value of W1 / W2, and the vertical axis represents the per-unit value of the back EMF. Back EMF refers to the electromotive force generated by resisting the trend of current change. The physical meaning of back EMF is that back EMF can generate useful energy and is inversely correlated with heat loss, reflecting the ability of the appliance to convert input energy into effective energy. The per-unit value of back EMF is the ratio obtained by dividing the actual value of back EMF by its corresponding reference value, which is a dimensionless relative value. By using the per-unit value, analysis and calculation can be carried out more conveniently.

[0053] from Fig. 9 It can be seen that when the value of W1 / W2 is in the range of 0 to 8, the per-unit value of the back EMF increases first and then decreases. Fig. 9 The curve in is explained as follows: When the value of W1 / W2 is less than 1.2, the maximum width W1 of the first mounting slot 130 is small, and the minimum width W2 is large. Although the magnetic flux emission area of ​​the connecting section 140 is larger, the area of ​​the first core block 210 close to the air gap will be reduced, which is easy to cause magnetic circuit saturation. No matter how much magnetic flux is generated, it cannot pass through, resulting in a reduction in the total magnetic flux, which will lead to a decrease in the per-unit value of the back electromotive force. When the value of W1 / W2 is greater than 5, the maximum width W1 of the first mounting slot 130 is large, and the minimum width W2 is small. The magnetic flux emission area of ​​the connecting section 140 is reduced, and the connecting section 140 is difficult to provide the magnetic flux. It mainly relies on the first magnetic section 110 and the second magnetic section 120 to provide the magnetic flux, which will lead to a reduction in the total magnetic flux and a decrease in the per-unit value of the back electromotive force.

[0054] Therefore, a reasonable design of W1 / W2 value within the range of 1.2 to 5 can ensure that the first core block 210 has a reasonable magnetic flux area, reduce the magnetic circuit saturation, and at the same time increase the magnetic flux emission area of ​​the connecting section 140 to increase the air gap magnetic density, thereby increasing the back electromotive force per unit value and improving the performance of the motor.

[0055] Reference Figure 4 and Figure 5As shown, in the third embodiment of the utility model, one end of the first magnetic segment 110 close to the rotation axis and one end of the second magnetic segment 120 close to the rotation axis are directly connected and the angle is less than 90°, the rotor core 200 also includes a body 230, the outer edge of the body 230 is provided with a plurality of grooves 232 at intervals, the plurality of grooves 232 are arranged around the rotation axis, and an accommodation groove 231 is formed between the first core block 210 and the inner wall of the groove 232, and the permanent magnet 100 is integrally injection molded in the accommodation groove 231. It can be understood that by setting the angle between the first magnetic segment 110 and the second magnetic segment 120 to be less than 90°, more permanent magnets 100 can be arranged along the circumference of the rotor assembly 1000, which can increase the magnetic flux and improve the working efficiency of the motor; and the magnetic density is increased, which can increase the magnetic load of the motor, reduce the speed of the motor, and increase the output torque, which is suitable for some heavy load occasions. Among them, the permanent magnet 100 is connected to the rotor core 200 by an integral injection molding method, which can simplify the installation of the permanent magnet 100 and ensure that the permanent magnet 100 can perfectly fit the shape of the receiving slot 231, with high assembly efficiency, and no need to set a limit protrusion to limit the position of the permanent magnet 100, which can effectively reduce magnetic leakage and improve the working efficiency of the motor. Alternatively, as an alternative embodiment, the permanent magnet 100 can also be manufactured and formed first, and then installed in the receiving slot 231, and a suitable solution is selected according to the actual situation.

[0056] Reference Figure 6 As shown, in the fourth embodiment of the present invention, one end of the first magnetic segment 110 close to the rotation axis is directly connected to one end of the second magnetic segment 120 close to the rotation axis, and the angle between the first magnetic segment 110 and the second magnetic segment 120 is greater than 90° and less than 180°. Figure 7As shown, as an alternative embodiment, the angle between the first magnetic segment 110 and the second magnetic segment 120 can also be 90°. The rotor core 200 also includes a body 230, and the outer edge of the body 230 is provided with a plurality of grooves 232 at intervals, and the plurality of grooves 232 are arranged around the rotation axis. An accommodating groove 231 is formed between the first core block 210 and the inner wall of the groove 232, and the permanent magnet 100 is integrally injection molded in the accommodating groove 231. It can be understood that by setting the angle between the first magnetic segment 110 and the second magnetic segment 120 to be greater than or equal to 90° and less than 180°, fewer permanent magnets 100 can be arranged along the circumference of the rotor assembly 1000, reducing the number of permanent magnets 100, reducing magnetic load, reducing air gap magnetic density, reducing back electromotive force, and reducing the iron loss ratio during light load operation. In the case of light load operation, the working efficiency of the motor can be improved. Among them, the permanent magnet 100 is connected to the rotor core 200 by integral injection molding, which can simplify the installation of the permanent magnet 100 and ensure that the permanent magnet 100 can perfectly adapt to the shape of the accommodating groove 231. The assembly efficiency is high, and there is no need to set a limit protrusion to limit the position of the permanent magnet 100. It can effectively reduce leakage flux and improve the working efficiency of the motor.

[0057] Reference Figure 4 As shown, in an embodiment of the utility model, along the circumference of the rotor assembly 1000, the maximum width of the end of the first mounting slot 130 away from the axis of rotation is W1, and the maximum width between the outer side surface of the first magnetic segment 110 and the outer side surface of the second magnetic segment 120 is W3, satisfying: 0.48≤W1 / W3≤0.85, for example, the value of W1 / W3 can be 0.48, 0.5, 0.6, 0.7, 0.71, 0.73, 0.76, 0.77, 0.8, 0.83, 0.85, etc. It should be noted that the outer side surface of the first magnetic segment 110 and the outer side surface of the second magnetic segment 120 refer to the side surfaces of the first magnetic segment 110 and the second magnetic segment 120 that are away from the first mounting slot 130. Among them, W1 / W3 reflects the thickness of the permanent magnet 100. Refer to Fig.10 As shown, Fig.10 The horizontal axis represents the value of W1 / W3, and the vertical axis represents the per unit value of the back EMF. Fig.10 It can be seen that when the value of W1 / W3 is in the range of 0.4 to 1, the per-unit value of the back EMF increases first and then decreases. Fig.10 The curve in is explained as follows:

[0058] When the value of W1 / W3 is less than 0.48, the width W1 of the end of the first mounting slot 130 away from the rotation axis is small, the maximum width W3 between the first magnetic segment 110 and the second magnetic segment 120 is large, and the thickness of the permanent magnet 100 is thick, resulting in a reduction in the area of ​​the outer side of the first core block 210, and the magnetic circuit is easily saturated, resulting in a reduction in the total magnetic flux, a reduction in the back electromotive force, and a reduction in the performance of the motor. When the value of W1 / W3 is greater than 0.85, the width W1 of the end of the first mounting slot 130 away from the rotation axis is large, the maximum width W3 between the first magnetic segment 110 and the second magnetic segment 120 is small, the thickness of the permanent magnet 100 is reduced, the magnetic flux is reduced, the air gap magnetic density is reduced, the back electromotive force is reduced, and the performance of the motor is also reduced.

[0059] Therefore, by designing the value of W1 / W3 within the range of 0.7 to 0.85, the area of ​​the outer side surface of the first core block 210 can be made appropriate, avoiding oversaturation of the magnetic circuit, increasing the magnetic flux, increasing the back electromotive force, and improving the performance of the motor.

[0060] Reference Figure 1 and Figure 8 As shown, in an embodiment of the utility model, the outer end face of the first magnetic segment 110 and / or the outer end face of the second magnetic segment 120 is a plane. It should be noted that the outer end face of the first magnetic segment 110 and the outer end face of the second magnetic segment 120 refer to the end face close to the air gap of the motor. For example, the outer end face of the first magnetic segment 110 is a plane, and the outer end face of the second magnetic segment 120 is an arc surface; or the outer end face of the first magnetic segment 110 is an arc surface, and the outer end face of the second magnetic segment 120; or the outer end face of the first magnetic segment 110 and the outer end face of the second magnetic segment 120 are both planes. It can be understood that the outer end face of the first magnetic segment 110 and the outer end face of the second magnetic segment 120 are both planes, which can facilitate the production and manufacturing of the permanent magnet 100, with a simple structure and high production efficiency.

[0061] Reference Figure 8 As shown, in the embodiment of the utility model, based on the scheme of the first embodiment, since the outer end faces of the first magnetic segment 110 and the second magnetic segment 120 are both planes, a plastic coating groove 160 is formed at the outer end faces of the first magnetic segment 110 and the second magnetic segment 120, and the plastic coating groove 160 is used to fill the plastic coating material 170, thereby improving the stability and reliability of the plastic coating material 170 when connected to the rotor core 200 and the permanent magnet 100, and reducing the risk of the plastic coating material 170 loosening and falling off.

[0062] Reference Figure 2As shown, in the embodiment of the utility model, the outer side surface of the first core block 210 is a first arc surface 211, the outer side surface of the first magnetic segment 110 is a second arc surface 111, and the outer side surface of the second magnetic segment 120 is a third arc surface 121. The radii of the first arc surface 211, the second arc surface 111 and the third arc surface 121 are the same, and the position of the center of the circle coincides with the axis of rotation. Therefore, the outer side surface of the rotor assembly 1000 is an arc surface, and when an air gap is formed with the stator assembly of the motor, the uniformity of the air gap can be improved to improve the magnetic field waveform, reduce the harmonic content, and thus improve the efficiency of the motor. By optimizing the air gap design, the magnetic flux density distribution of the motor can be made more uniform, pulsation can be reduced, and efficiency can be further improved. An uneven air gap can cause magnetic field distortion, increase harmonic current and additional harmonic iron loss and copper loss, affect motor efficiency, and cause greater vibration and noise during motor operation. Therefore, a uniform air gap can also help reduce iron loss and copper loss, while reducing the cogging torque amplitude, thereby increasing the motor's output torque, improving the smoothness of motor operation, and reducing noise.

[0063] Reference Figure 1 As shown, in the embodiment of the present invention, the first core block 210 is provided with a positioning hole 240, and the positioning hole 240 is set at both ends of the first core block 210 along its axial direction. During the overmolding process, the positioning hole 240 is used to cooperate with the positioning column, positioning protrusion and other structures to determine the position of the rotor assembly 1000, which is convenient for the subsequent overmolding process and improves the overmolding accuracy. Figure 2 As shown, in another embodiment, the first core block 210 and the second core block 220 are both provided with positioning holes 240, which can further improve the positioning accuracy and stability, avoid the position of the rotor assembly 1000 from being offset or misaligned, and improve the stability and reliability of the overmolding. As an alternative embodiment, in addition to the positioning hole 240, a positioning groove, a blind hole, or a positioning boss can also be used, and a suitable solution can be selected according to the actual situation.

[0064] The motor of one embodiment of the utility model comprises a stator assembly and a rotor assembly 1000 of the above embodiment. The rotor assembly 1000 is arranged on the inner side of the stator assembly and is arranged at a distance from the stator assembly, so the motor is an inner rotor motor. The gap between the stator assembly and the rotor assembly 1000 is called an air gap. The motor of the utility model embodiment adopts the rotor assembly 1000 of the above embodiment. The rotor assembly 1000 is arranged around the rotation axis of the rotor assembly 1000 by arranging a plurality of permanent magnets 100. The first magnetic segment 110 and the second magnetic segment 120 of the permanent magnet 100 are arranged at an angle to each other and form a first mounting groove 130. The first core block 210 of the rotor core 200 is arranged in the first mounting groove 130, and the outer side surface of the first core block 210 is exposed to the opening. Therefore, the magnetic flux of the first magnetic segment 110 and the second magnetic segment 120 can enter the first core block 210, and then enter the air gap of the motor through the outer side surface of the first core block 210, so as to improve the magnetic concentration effect, increase the air gap magnetic density, and improve the torque density, so as to improve the performance of the motor. The first core block 210 is fixedly connected to the permanent magnet 100 by means of plastic coating, so there is no need to set structures such as limiting protrusions, which can effectively reduce magnetic leakage and further improve the working efficiency of the motor.

[0065] 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.

[0066] A household appliance of one embodiment of the utility model comprises the motor of the above embodiment, and the household appliance may be an air conditioner, a refrigerator, a washing machine, a humidifier, a vacuum cleaner, a dehumidifier and the like. The household appliance of the utility model embodiment adopts the motor of the above embodiment, and the rotor assembly 1000 of the motor is arranged by arranging a plurality of permanent magnets 100 around the rotation axis of the rotor assembly 1000, and the first magnetic segment 110 and the second magnetic segment 120 of the permanent magnet 100 are arranged at an angle to each other and form a first mounting groove 130, and the first core block 210 of the rotor core 200 is arranged in the first mounting groove 130, and the outer side surface of the first core block 210 is exposed in the opening. Therefore, the magnetic flux of the first magnetic segment 110 and the second magnetic segment 120 can enter the first core block 210, and then enter the air gap of the motor through the outer side surface of the first core block 210, so as to improve the magnetic concentration effect, increase the air gap magnetic density, and improve the torque density, so as to improve the performance of the motor. The first core block 210 is fixedly connected to the permanent magnet 100 by means of plastic coating, so there is no need to set structures such as limiting protrusions, which can effectively reduce magnetic leakage and further improve the working efficiency of the motor.

[0067] Since the household appliance adopts all the technical solutions of the motor of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment, which will not be described in detail here.

[0068] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A rotor assembly, characterized in that: include: A plurality of permanent magnets are arranged around the rotation axis of the rotor assembly, the permanent magnets include a first magnetic segment and a second magnetic segment arranged at an angle to each other, a first mounting groove is formed between the first magnetic segment and the second magnetic segment, the first mounting groove is provided with an opening along the radial direction of the rotor assembly, and the opening faces a side away from the rotation axis; The rotor core includes a plurality of first core blocks, the number of the first core blocks is the same as the number of the permanent magnets, the plurality of first core blocks are correspondingly arranged in the plurality of first mounting grooves, the outer side surfaces of the first core blocks are exposed in the openings, and the first core blocks are fixedly connected to the permanent magnets by plastic coating.

2. The rotor assembly according to claim 1, characterized in that: The permanent magnet further includes a connecting segment, two ends of which are respectively connected to one end of the first magnetic segment and one end of the second magnetic segment close to the rotation axis.

3. The rotor assembly according to claim 2, characterized in that: Among two adjacent permanent magnets, a side surface of the first magnetic segment of one of the permanent magnets abuts against a side surface of the second magnetic segment of the other permanent magnet.

4. The rotor assembly according to claim 2, characterized in that: A second installation groove is formed between two adjacent permanent magnets, and the rotor core also includes second core blocks with the same number as the permanent magnets. Multiple second core blocks are arranged in the corresponding second installation grooves, and along the circumference of the rotor assembly, multiple first core blocks and multiple second core blocks are alternately arranged in sequence.

5. The rotor assembly according to claim 2, characterized in that: Along the circumference of the rotor assembly, the maximum width of the first mounting groove at one end away from the rotation axis is W1, and the minimum width of the first mounting groove at one end close to the rotation axis is W2, satisfying: 1.2≤W1 / W2≤5.

6. The rotor assembly according to claim 1, characterized in that: One end of the first magnetic segment close to the rotation axis is connected to the other end of the second magnetic segment close to the rotation axis. The rotor core includes a main body. A plurality of grooves surrounding the rotation axis are arranged at intervals on the outer edge of the main body. An accommodating groove is formed between the first core block and the inner wall of the groove. The permanent magnet is arranged in the accommodating groove.

7. The rotor assembly according to claim 6, characterized in that: The permanent magnet is integrally injection-molded in the accommodating groove.

8. The rotor assembly according to claim 1, characterized in that: Along the circumference of the rotor assembly, the maximum width of the first mounting groove at one end away from the rotation axis is W1, and the maximum width between the outer side surface of the first magnetic segment and the outer side surface of the second magnetic segment is W3, satisfying: 0.48≤W1 / W3≤0.

85.

9. The rotor assembly according to claim 1, characterized in that: An outer end surface of the first magnetic segment and / or an outer end surface of the second magnetic segment is a plane.

10. The rotor assembly according to claim 9, characterized in that: Among the two adjacent permanent magnets, the first magnetic segment of one of the permanent magnets is abutted against the second magnetic segment of the other permanent magnet, and the outer end surfaces of the first magnetic segment and the second magnetic segment are both planes and formed with a plastic coating groove, and the plastic coating groove is used to fill the plastic coating material.

11. The rotor assembly according to claim 1, characterized in that: The outer side surface of the first core block is a first arc surface, the outer side surface of the first magnetic segment is a second arc surface, and the outer side surface of the second magnetic segment is a third arc surface. The radii of the first arc surface, the second arc surface and the third arc surface are the same, and the centers of the circles are all located at the rotation axis.

12. The motor is characterized by: Comprising a rotor assembly as claimed in any one of claims 1 to 11.

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

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