Electric motor and electric appliance

Abstract

Disclosed in the present application are an electric motor and an electric appliance. The electric motor comprises a stator assembly and a rotor assembly, wherein the stator assembly comprises a stator iron core provided with an inner stator hole therein; the rotor assembly is arranged in the inner stator hole, and comprises a rotor iron core and a plurality of rotor magnetic poles which are arranged on the rotor iron core in a circumferential direction of the rotor iron core and divide the rotor iron core into a plurality of iron core units; an outer contour of at least one iron core unit comprises one or more arc segments, and the stator iron core has a circular virtual inner contour; and a first gap is formed between the outer contour of the iron core unit and the virtual inner contour of the stator iron core, and the first gap located on a first side of the iron core unit is larger than the first gap located on a second side of the iron core unit, the first side being the side of the rotor assembly in a rotating direction, and the second side being the side of the rotor assembly in a reverse rotating direction.

Description

Motors and electrical appliances

[0001] This application claims priority to Chinese patent application No. 202310713446.8 filed on June 15, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of motor technology, and in particular to a motor and an electrical appliance. Background Art

[0003] To improve the torque ripple and radial electromagnetic force of built-in permanent magnet synchronous motors, arc cutting is typically performed on the rotor core and stator teeth. Traditional arc cutting methods are symmetrical about the centerline of the rotor core or the centerline of the stator teeth. However, in applications where motors such as fans and compressors only operate in one-way rotation, local saturation points will always appear on the stator teeth in the opposite direction of rotation due to the fixed phase relationship between the armature magnetic field and the permanent magnet magnetic field. This local saturation point significantly increases the motor's iron loss, torque ripple, and radial electromagnetic force, leading to a decrease in motor efficiency. Technical issues

[0004] The main purpose of this application is to provide a motor that aims to reduce the iron loss of the motor and improve the output efficiency of the motor. Technical Solutions

[0005] To achieve the above-mentioned purpose, the motor proposed in this application includes:

[0006] A stator assembly includes a stator core having a stator inner bore; and

[0007] a rotor assembly disposed in the inner hole of the stator, the rotor assembly comprising a rotor core and a plurality of rotor poles, the plurality of rotor poles being disposed on the rotor core along a circumferential direction of the rotor core and separating the rotor core into a plurality of core units; an outer contour of at least one of the core units comprising one or more circular arcs, and the stator core having a circular virtual inner contour;

[0008] There is a first gap between the outer contour line of the core unit and the virtual inner contour line of the stator core. The first gap located on the first side of the core unit is larger than the first gap located on the second side of the core unit. The first side is the side in the rotation direction of the rotor assembly, and the second side is the side in the reverse rotation direction of the rotor assembly.

[0009] In one embodiment, the outer contour line of at least one of the core units is divided into a first arc segment and a second arc segment by its midline, the first arc segment and the second arc segment are arranged sequentially along the direction of rotation of the rotor assembly, and the maximum width of the first gap at the second arc segment is greater than the maximum width of the first gap at the first arc segment.

[0010] In one embodiment, the first arc segment is composed of a plurality of sub-arcs with the same or different curvatures, and the centers of the sub-arcs are located on the same side of the second arc segment as the center of the rotor core; or

[0011] The second arc segment is composed of a plurality of sub-arcs with the same or different curvatures, and the centers of the sub-arcs are located on the same side of the second arc segment as the center of the rotor core.

[0012] In one embodiment, the width of the first gap in the second arc segment gradually increases from the center line toward a direction away from the center line.

[0013] In one embodiment, the first arc segment includes a first sub-arc segment and a second sub-arc segment, and the second sub-arc segment is arranged close to the center line;

[0014] The maximum width of the first gap in the first sub-arc segment is smaller than the maximum width of the first gap in the second sub-arc segment.

[0015] In one embodiment, the second arc segment includes a third sub-arc segment and a fourth sub-arc segment, and the third sub-arc segment is arranged close to the center line;

[0016] The maximum width of the first gap in the fourth sub-arc segment is greater than the maximum width of the first gap in the third sub-arc segment;

[0017] The maximum width of the first gap in the fourth sub-arc segment is greater than the maximum width of the first gap in the first sub-arc segment.

[0018] In one embodiment, the second sub-arc segment is smoothly connected to the third sub-arc segment, and the first gap has the same width as the second sub-arc segment and the third sub-arc segment.

[0019] In one embodiment, the width of the first gap in the fourth sub-arc segment gradually increases from the connection point of the fourth sub-arc segment and the third sub-arc segment toward a direction away from the center line;

[0020] And / or, the width of the first gap in the first sub-arc segment gradually increases from the connection point of the first sub-arc segment and the second sub-arc segment toward the direction away from the center line.

[0021] In one embodiment, the rotor core has a circular virtual outer contour line, and a second gap is formed between the virtual outer contour line of the rotor core and the tooth contour line of the stator core. The second gap located on the second side of the core unit is larger than the second gap located on the first side of the core unit.

[0022] In one embodiment, the first gap and the second gap together constitute an air gap between the rotor core and the stator core.

[0023] In one embodiment, a ratio of a maximum width of the second gap at the first arc segment to a minimum width of the second gap is less than 2.5 and greater than 1;

[0024] And / or, the ratio of the maximum width of the second gap at the second arc segment to the minimum width of the second gap is less than 2.5, greater than 1;

[0025] And / or, the ratio of the maximum width of the second gap at the first arc segment to the minimum width of the second gap is smaller than the ratio of the maximum width of the second gap at the second arc segment to the minimum width of the second gap.

[0026] In one embodiment, the stator core has a stator slot, the number of the stator slots is Q1, the number of the rotor poles is Q2;

[0027] Q1 and Q2 satisfy: Q2=Q1±2, or Q2=Q1±4.

[0028] The present application also provides an electrical appliance, which includes the motor described in any of the aforementioned embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0030] FIG1 is a schematic structural diagram of an embodiment of a motor of the present application;

[0031] FIG2 is a schematic structural diagram of another embodiment of the motor of the present application;

[0032] FIG3 is a schematic structural diagram of another embodiment of the motor of the present application;

[0033] FIG4 is a schematic structural diagram of an embodiment of a motor of the present application;

[0034] FIG5 is a schematic structural diagram of another embodiment of the motor of the present application;

[0035] FIG6 is a schematic structural diagram of an embodiment of the stator assembly in FIG5 ;

[0036] FIG7 is a diagram showing the relationship between iron loss and the central angle of the eccentric arc of the second arc segment in FIG2 according to an embodiment;

[0037] FIG8 is a graph showing the relationship between motor efficiency and the central angle of the eccentric arc of the second arc segment in FIG2 according to an embodiment;

[0038] FIG9 is a diagram showing the relationship between torque fluctuation and the central angle of the eccentric arc of the second arc segment in FIG2 according to an embodiment;

[0039] FIG10 is a diagram showing the relationship between radial force and the central angle of the eccentric arc of the second arc segment in FIG2 according to an embodiment;

[0040] FIG11 is a magnetic flux density cloud diagram of a motor using the existing rotor arc cutting technology;

[0041] FIG12 is a magnetic flux density cloud diagram of the motor of the present application.

[0042] Description of Figure Numbers:

[0043] Reference numerals: Reference numerals: 1. Motor 100. Rotor core 10. Rotor assembly 110. Core unit 20. Stator assembly 111. First arc segment 21. Stator core 111a. First sub-arc segment 21a. Stator yoke 111b. Second sub-arc segment 21b. Stator tooth 112. Second arc segment 21c. Stator shoe 112a. Third sub-arc segment 22. Stator slot 112b. Fourth sub-arc segment 30. Air gap 200. Rotor pole

[0044] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0045] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0046] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0047] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0048] The present application provides a motor.

[0049] In the embodiment of the present application, as shown in Figures 1 to 12, the motor 1 includes a stator assembly 20 and a rotor assembly 10, the stator assembly 20 includes a stator core 21, and the stator core 21 has a stator inner hole; the rotor assembly 10 is arranged in the stator inner hole, and the rotor assembly 10 includes a rotor core 100 and a plurality of rotor poles 200, and the plurality of rotor poles 200 are arranged on the rotor core 100 along the circumference of the rotor core 100, and the rotor core 100 is separated into a plurality of core units 110; at least The outer contour line of one of the core units 110 includes one or more circular arcs, and the stator core 100 has a circular virtual inner contour line; a first gap is formed between the outer contour line of the core unit 110 and the virtual inner contour line of the stator core 100, and the first gap on the first side of the core unit 110 is larger than the first gap on the second side of the core unit 110. The first side is a side in the rotation direction of the rotor assembly 10, and the second side is a side in the reverse rotation direction of the rotor assembly 10.

[0050] The stator core 100 has a circular virtual inner contour line that is tangent to all stator boots 21c. The rotor assembly 10 is an important component of the stator assembly 20 in the motor 1. The rotor assembly 10 is usually used in conjunction with the stator assembly 20. The rotor assembly 10 and the stator assembly 20 can be sold together as a motor 1, or they can be produced and sold separately. Generally, the stator assembly 20 includes a stator core 21, which has a stator inner hole; the rotor assembly 10 is disposed in the stator inner hole, and an air gap 30 is formed between the rotor core 100 and the stator core 21.

[0051] In one embodiment, referring to Figures 4 and 5 , a rotor assembly 10 generally includes a rotor core 100 and rotor poles 200. A plurality of rotor poles 200 are arranged circumferentially around the rotor core 100, dividing the rotor core 100 into a plurality of core units 110. The ends of the core units 110 near the center of the rotor core 100 may be connected or disconnected. Furthermore, the ends of the core units 110 away from the center of the rotor core 100 are disconnected, thereby preventing magnetic flux leakage from the rotor core 100.

[0052] Furthermore, each core unit 110 has a centerline passing through the center of the rotor core 100; the outer contour of at least one core unit 110 is divided into a first arc segment 111 and a second arc segment 112 by its centerline, and the maximum width of the first gap at the second arc segment 112 is greater than the maximum width of the first gap at the first arc segment 111. For example, referring to Figures 1 and 2, point O is the center of the rotor core 100, and the centerline passing through point O is the centerline of the core unit 110. H1 is the distance from the first arc segment 111 to the center of the rotor core 100, and H2 is the distance from the first arc segment 111 to the center of the rotor core 100. It can be understood that the minimum value of H2 is less than the minimum value of H1. Thus, when this rotor assembly 10 is applied to the motor 1, the air gap 30 at the second arc segment 112 is increased, thereby effectively improving tooth shoe saturation, reducing iron loss in the motor 1, improving motor 1 efficiency, and improving torque ripple and radial electromagnetic force.

[0053] It should be understood that the rotor assembly 10 described in the present application is applied to a unidirectional rotating motor 1, i.e., a motor 1 that rotates in only one direction, wherein a local saturation point always occurs at a position opposite to the rotation direction of the stator shoe 21c, and the first arc segment 111 and the second arc segment 112 are arranged sequentially along the rotation direction of the rotor assembly 10. For example, referring to Figures 1 to 3, when the rotor assembly 10 rotates counterclockwise, a local saturation point is likely to occur at a position to the right of the stator shoe 21c, and the second arc segment 112 is located to the left of the centerline of the core unit 110 where it is located, passing through the center of the rotor core 100, while the first arc segment 111 is located to the right of the centerline of the core unit 110 where it is located, passing through the center of the rotor core 100. If the rotation direction of the rotor assembly 10 is clockwise, a local saturation point is likely to appear at the left side of the stator shoe 21c, and the second arc segment 112 is located to the right of the center line of the core unit 110 passing through the center of the rotor core 100, and the first arc segment 111 is located to the left of the center line of the core unit 110 passing through the center of the rotor core 100.

[0054] The motor 1 provided in the present application includes a stator assembly 20 and a rotor assembly 10, wherein the stator assembly 20 includes a stator core 21, and the stator core 21 has a stator inner hole; the rotor assembly 10 is arranged in the stator inner hole, and the rotor assembly 10 includes a rotor core 100 and a plurality of rotor poles 200, wherein the plurality of rotor poles 200 are arranged on the rotor core 100 along the circumference of the rotor core 100 and separate the rotor core 100 into a plurality of core units 110; the outer contour line of at least one of the core units 110 includes one or more circular arcs, and the stator core 100 has a circular virtual inner contour line; a first gap is formed between the outer contour line of the core unit 110 and the virtual inner contour line of the stator core 100, and the first gap located on the first side of the core unit 110 is larger than the first gap located on the second side of the core unit 110, the first side is the side in the rotation direction of the rotor assembly 10, and the second side is the side in the opposite rotation direction of the rotor assembly 10. In this way, the technical solution of the present application increases the air gap 30 at the second arc segment 112 to avoid the occurrence of local saturation points in the stator shoe portion 21c in the opposite direction of rotation, thereby effectively improving the tooth shoe saturation, reducing the iron loss of the motor 1, improving the efficiency of the motor 1, and improving the torque pulsation and radial electromagnetic force.

[0055] Referring to Figures 1 and 2 , in one embodiment, the distance between the second arc segment 112 and the center of the rotor core 100 gradually decreases from the centerline toward a direction away from the centerline. This facilitates manufacturing and further prevents the occurrence of local saturation points in the stator shoe 21c in the direction opposite to the rotational direction, thereby further improving tooth shoe saturation, reducing iron loss in the motor 1, improving motor efficiency, and improving torque ripple and radial electromagnetic force.

[0056] Further, please refer to Figures 2, 7 to 10, Figure 7 is a relationship diagram between iron loss and the eccentric arc central angle of the second arc segment 112 in Figure 2 in an embodiment; Figure 8 is a relationship diagram between the efficiency of the motor 1 and the eccentric arc central angle of the second arc segment 112 in Figure 2 in an embodiment; Figure 9 is a relationship diagram between torque fluctuation and the eccentric arc central angle of the second arc segment 112 in Figure 2 in an embodiment; Figure 10 is a relationship diagram between radial force and the eccentric arc central angle of the second arc segment 112 in Figure 2 in an embodiment. Among them, d1 is the first gap between the outer contour line of the core unit and the virtual inner contour line of the stator core, point O is the center of the rotor core 100, point O' is the center of the second arc segment 112, and the center line passing through point O is the angle between the center line of the core unit 110 and the OO' line, that is, the center angle of the eccentric arc, that is, the ɑ angle in Figure 2. A negative value of the ɑ angle indicates that O' is located on the right side of the center line, and a positive value indicates that O' is located on the left side of the center line. In Figures 7 to 10, the relationship diagrams of iron loss, motor 1 efficiency, torque ripple and radial force with the center angle of the eccentric arc are data relationship diagrams obtained through finite element simulation. It can be seen from the figure that when ɑ takes a value of -2° to -10°, the rotor assembly 10 has the best effect on improving tooth boot saturation, reducing motor 1 iron loss, improving motor 1 efficiency, and improving torque pulsation and radial electromagnetic force. In addition, the meaning of -2° to -10° refers to that the angle is extended in the direction of the center line toward the line OO', and the angle between the center line and the line OO' is between 2° and 10°. Specifically, the value of ɑ includes but is not limited to 2°, 3°, 4°, 5°, 6°, 7°, 8°, 9°, or 10°.

[0057] In an exemplary embodiment, the first arc segment 112 is composed of a plurality of sub-arcs with the same or different curvatures, and the centers of the sub-arcs are located on the same side of the second arc segment 112 as the center of the rotor core 100; or, the second arc segment 112 is composed of a plurality of sub-arcs with the same or different curvatures, and the centers of the sub-arcs are located on the same side of the second arc segment 112 as the center of the rotor core 100. It should be understood that the second arc segment 112 can be an arc with the same curvature, or it can be a combination of multiple arcs with different curvatures. In the embodiment of multiple arcs with different curvatures, the multiple segments are connected with a smooth transition, and the center of the arc corresponding to the center is located on the same side of the second arc segment 112 as the center of the rotor core 100. Similarly, the first arc segment 111 can be an arc with the same curvature, or it can be a combination of multiple arcs with different curvatures. In the embodiment of multiple arcs with different curvatures, the multiple segments are connected with a smooth transition, and the center of the arc corresponding to the center is located on the same side of the first arc segment 111 as the center of the rotor core 100.

[0058] Please refer to FIG. 3 . In an exemplary embodiment, the width of the first gap in the second arc segment 111 b gradually increases from the center line toward a direction away from the center line.

[0059] Please refer to Figure 3. In an exemplary embodiment, the first arc segment 111 includes a first sub-arc segment 111a and a second sub-arc segment 111b, and the second sub-arc segment 111b is arranged close to the center line; the maximum width of the first gap in the first sub-arc segment 111a is smaller than the maximum width of the first gap in the second sub-arc segment 111b.

[0060] Based on the previous embodiment, to further reduce the iron loss of the motor 1 or to improve the output efficiency of the motor 1, the second arc segment 112 includes a third sub-arc segment 112a and a fourth sub-arc segment 112b, wherein the third sub-arc segment 112a is located near the centerline; the maximum width of the first gap in the fourth sub-arc segment 112b is greater than the maximum width of the first gap in the third sub-arc segment 112a; and the maximum width of the first gap in the fourth sub-arc segment 112b is greater than the maximum width of the first gap in the first sub-arc segment 111a. Preferably, the second sub-arc segment 111b is smoothly connected to the third sub-arc segment 112a, and the second sub-arc segment 111b and the third sub-arc segment 112a are equidistant from the center of the rotor core 100.

[0061] In one embodiment, the distance between the first gap and the center of the rotor core 100 in the fourth sub-arc segment 112b gradually increases from the connection between the fourth sub-arc segment 112b and the third sub-arc segment 112a toward the direction away from the centerline. Furthermore, the width of the first gap in the first sub-arc segment gradually increases from the connection between the first sub-arc segment 111a and the second sub-arc segment 111b toward the direction away from the centerline.

[0062] Referring to Figures 5 and 6 , in one embodiment, the rotor core 100 has a circular virtual outer contour. A second gap is defined between the virtual outer contour of the rotor core 100 and the tooth contour of the stator core 21. The second gap located on the second side of the core unit 110 is larger than the second gap located on the first side of the core unit 110. The circular virtual outer contour of the rotor core 100 is tangent to all core units 110, and d2 is the second gap between the virtual outer contour of the rotor core and the tooth contour of the stator core 100. Furthermore, the first and second gaps together constitute the air gap between the rotor core 100 and the stator core 21.

[0063] Considering that the air gap 30 between the rotor core 100 and the stator core 21 needs to be within a reasonable range to achieve low torque ripple, low noise, and high efficiency for the motor 1, experiments have shown that when the ratio of the maximum width of the second gap at the first arc segment 111 to the minimum width of the second gap is less than 2.5 and greater than 1; the ratio of the maximum width of the second gap at the second arc segment 112 to the minimum width of the second gap is less than 2.5 and greater than 1, and the ratio of the maximum width of the second gap at the first arc segment 111 to the minimum width of the second gap is less than the ratio of the maximum width of the second gap at the second arc segment 112 to the minimum width of the second gap. Within this range, the torque ripple, noise, and output efficiency of the motor 1 are significantly improved.

[0064] It is understood that the ratio of the maximum width of the second gap at the second arc segment 112 to the minimum width of the second gap is greater than the ratio of the maximum width of the second gap at the first arc segment 111 to the minimum width of the second gap. The ratio of the maximum width of the second gap at the first arc segment 111 to the minimum width of the second gap / the ratio of the maximum width of the second gap at the second arc segment 112 to the minimum width of the air gap 30 can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, or 2.4.

[0065] Exemplarily, the minimum width of the second gap is 0.40 mm, then the width of the second gap at the second arc segment 112 ranges from greater than 0.40 mm to less than 1.0 mm, and the width of the second gap at the first arc segment 111 ranges from greater than 0.40 mm to less than 1.0 mm. Specifically, the maximum width of the second gap at the second arc segment 112 includes but is not limited to 0.45mm, 0.50mm, 0.55mm, 0.60mm, 0.65mm, 0.70mm, 0.75mm, 0.80mm, 0.85mm, 0.90mm, 0.95mm or 0.99mm; the maximum width of the second gap at the first arc segment 111 includes but is not limited to 0.42mm, 0.45mm, 0.50mm, 0.55mm, 0.60mm, 0.65mm, 0.70mm, 0.75mm, 0.80mm, 0.85mm, 0.90mm or 0.95mm. And the width of the second gap at the first arc segment 111 / the minimum width of the second gap needs to be smaller than the width of the second gap at the second arc segment 112 / the minimum width of the second gap, that is, the maximum width of the second gap at the first arc segment 111 is smaller than the maximum width of the second gap at the second arc segment.

[0066] Please refer to Figures 5 and 6. The stator assembly 20 generally includes a stator winding. The stator core 21 includes a stator yoke 21a, a stator tooth 21b and a stator shoe 21c. A stator slot 22 is formed between two adjacent stator teeth 21b. The stator winding is generally wound around the stator tooth 21b. Specifically, it can be wound around only one stator tooth 21b, or it can span multiple stator slots 22 and be wound around multiple stator teeth 21b.

[0067] Based on this, in one embodiment, the stator core 21 has stator slots 22. To reduce the number of stator slots 22 to Q1, the number of rotor poles 200 is Q2. Q1 and Q2 satisfy the following relationship: Q2 = Q1 ± 2, or Q2 = Q1 ± 4. Thus, when the number of stator slots 22 and rotor poles 200 is very close, the stator winding can be wound around only one stator tooth 21b, or around two adjacent stator teeth 21b, thereby reducing the size of the motor 1 and improving its output efficiency.

[0068] For example, the number Q1 of the stator slots 22 can be 12, and the number Q2 of the rotor poles 200 can be 8, 10, 14 or 16. For example, the number Q1 of the stator slots 22 is 12, and the number Q2 of the rotor poles 200 is 10.

[0069] Please refer to Figures 11 and 12. Figure 11 shows the magnetic flux density cloud diagram of a motor using conventional rotor arc cutting technology, while Figure 12 shows the magnetic flux density cloud diagram of the motor of the present application. After adopting the present technology, the magnetic flux density at the local saturation position of the stator tooth shoe 21c dropped from 1.78T to 1.64T, demonstrating that the saturation of the stator tooth shoe 21c has been effectively improved.

[0070] The present application also provides an electrical appliance, which includes the motor 1 described in any of the aforementioned embodiments. The specific structure of the motor 1 is referred to in the aforementioned embodiments. Since the electrical appliance of the present application adopts all the technical solutions of all the aforementioned embodiments, it at least has all the beneficial effects brought about by the technical solutions of the aforementioned embodiments, which will not be described in detail here. Among them, the electrical appliance can be a fan or a compressor, etc., or an electrical appliance having the rotor assembly 10, the motor 1, the fan or the compressor, etc., which is not specifically limited here.

[0071] The above description is merely an optional embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification and drawings under the inventive concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A motor, in, The motor comprises: A stator assembly includes a stator core having a stator inner bore; and A rotor assembly, the rotor assembly is arranged in the inner hole of the stator, the rotor assembly comprises a rotor core and a plurality of rotor poles, the plurality of rotor poles are arranged in the rotor core along the circumference of the rotor core, and the rotor core is separated into a plurality of core units; the outer contour line of at least one of the core units comprises one or more circular arcs, and the stator core has a circular virtual inner contour line; A first gap is formed between the outer contour line of the core unit and the virtual inner contour line of the stator core. The first gap on the first side of the core unit is larger than the first gap on the second side of the core unit. The first side is a side in the rotation direction of the rotor assembly, and the second side is a side in the reverse rotation direction of the rotor assembly.

2. The electric machine according to claim 1, in, The outer contour line of at least one of the core units is divided into a first arc segment and a second arc segment by the midline thereof, the first arc segment and the second arc segment are arranged sequentially along the direction of rotation of the rotor assembly, and the maximum width of the first gap at the second arc segment is greater than the maximum width of the first gap at the first arc segment.

3. The motor according to claim 2, in, The first arc segment is composed of a plurality of sub-arcs with the same or different curvatures, and the centers of the sub-arcs are located on the same side of the second arc segment as the center of the rotor core; or, The second arc segment is composed of a plurality of sub-arcs with the same or different curvatures, and the centers of the sub-arcs are located on the same side of the second arc segment as the center of the rotor core.

4. The electric machine according to claim 2 or 3, in, The width of the first gap in the second arc segment gradually increases from the center line toward a direction away from the center line.

5. The electric machine according to any one of claims 2 to 4, in, The first arc segment includes a first sub-arc segment and a second sub-arc segment, and the second sub-arc segment is arranged close to the center line; The maximum width of the first gap in the first sub-arc segment is smaller than the maximum width of the first gap in the second sub-arc segment.

6. The electric machine according to claim 5, in, The second arc segment includes a third sub-arc segment and a fourth sub-arc segment, and the third sub-arc segment is arranged close to the center line; The maximum width of the first gap in the fourth sub-arc segment is greater than the maximum width of the first gap in the third sub-arc segment; The maximum width of the first gap in the fourth sub-arc segment is greater than the maximum width of the first gap in the first sub-arc segment.

7. The electric machine according to claim 6, in, The second sub-arc segment is smoothly connected to the third sub-arc segment, and the first gap has the same width as the second sub-arc segment and the third sub-arc segment.

8. The electric machine according to claim 6 or 7, in, The width of the first gap in the fourth sub-arc segment gradually increases from the connection point between the fourth sub-arc segment and the third sub-arc segment toward a direction away from the center line; And / or, the width of the first gap in the first sub-arc segment gradually increases from the connection point of the first sub-arc segment and the second sub-arc segment toward the direction away from the center line.

9. The electric machine according to any one of claims 2 to 8, in, The rotor core has a circular virtual outer contour line, and a second gap is formed between the virtual outer contour line of the rotor core and the tooth contour line of the stator core. The second gap located on the second side of the core unit is larger than the second gap located on the first side of the core unit.

10. The electric machine according to claim 9, in, The first gap and the second gap together constitute an air gap between the rotor core and the stator core.

11. The electric machine according to claim 9 or 10, in, The ratio of the maximum width of the second gap at the first arc segment to the minimum width of the second gap is less than 2.5 and greater than 1; and / or a ratio of a maximum width of the second gap at the second arc segment to a minimum width of the second gap is less than 2.5 and greater than 1; And / or, a ratio of a maximum width of the second gap at the first arc segment to a minimum width of the second gap is smaller than a ratio of a maximum width of the second gap at the second arc segment to a minimum width of the second gap.

12. The electric machine according to any one of claims 2 to 11, in, The stator core has a stator slot, the number of the stator slots is Q1, the number of the rotor poles is Q2; Q1 and Q2 satisfy: Q2=Q1±2, or Q2=Q1±4.

13. An electrical appliance, in, The electrical appliance comprises: An electric machine as claimed in any one of claims 1 to 12.

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