Segmented outer rotor core, rotor assembly, and outer rotor motor having the same

Abstract

The application provides a split outer rotor core, a rotor assembly and an outer rotor motor with the same, wherein the split outer rotor core comprises a plurality of core segments which are uniformly spaced around a central axis of the split outer rotor core and are stacked by a plurality of core punching sheets, a magnetic steel slot is formed between two adjacent core segments, an auxiliary slot is formed on a radially inner side surface of the core punching sheet, and the auxiliary slot is recessed from inside to outside along a diameter direction of the split outer rotor core. The outer rotor core is of a split structure, there is no magnetic bridge between two adjacent core segments, a magnetic leakage path basically does not exist, the magnetic leakage of the motor is greatly reduced, and the performance of the motor is improved. On this basis, the auxiliary slot is arranged on the radially inner side surface of the core, and the motor cogging torque can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor manufacturing, and particularly relates to a block type outer rotor core, a rotor assembly and an outer rotor motor with the same. BACKGROUND

[0002] Compared with an inner rotor motor with the same motor external diameter, the outer rotor motor has a larger air gap diameter, and since the torque is directly proportional to the square of the air gap diameter, the output torque is also larger. Meanwhile, the motor length is smaller and the weight is lighter. In addition, the high rotational inertia of the outer rotor structure effectively reduces torque fluctuation, and the vibration and noise are small. The outer rotor structure is now widely used in the fields of fans, electric vehicle hub motors, washing machines and the like.

[0003] Cogging torque is an inherent characteristic of a permanent magnet motor, which can cause speed fluctuation, vibration and noise of the motor, and increase the starting torque of the motor. Reducing cogging torque is usually one of the main goals of permanent magnet motor design. However, for the block type outer rotor core, there is a lack of effective means to reduce cogging torque in the prior art, resulting in large torque ripple of the outer rotor motor. SUMMARY

[0004] Therefore, the present application provides a block type outer rotor core, a rotor assembly and an outer rotor motor with the same, which can solve the technical problem that the block type rotor core in the prior art lacks effective means to reduce cogging torque, resulting in large torque ripple of the outer rotor motor.

[0005] In order to solve the above problems, the present application provides a block type outer rotor core, which comprises a plurality of iron core segments uniformly spaced around a central axis of the block type outer rotor core and stacked by a plurality of iron core punches, a magnetic steel slot is formed between two adjacent iron core segments, an auxiliary slot is formed on an iron core radially inner side surface of the iron core punch, and the auxiliary slot is recessed from inside to outside along the diameter direction of the block type outer rotor core.

[0006] In some embodiments, each iron core punch has a first central symmetry plane in the diameter direction of the block type outer rotor core, the iron core punch comprises a punch body, the iron core punch is projected on any radial plane of the block type outer rotor core, the circumferential width of the punch body is B3, two auxiliary slots are arranged on the iron core radially inner side surface, the two auxiliary slots are symmetrical about the first central symmetry plane, and the central angle formed by the slot center lines of the two auxiliary slots and the center of the block type outer rotor core is ∠a, the projection of the iron core radially inner side surface comprises an inner side circular arc segment, the radius of the inner side circular arc segment is R 内 , and the slot opening circumferential width of each auxiliary slot is B7.

[0007] In some embodiments, the auxiliary slot is isosceles trapezoid, and the lower base of the isosceles trapezoid is close to the circumferential side of the segmented outer rotor core; and / or, the width of the slot opening close to the circumferential side of the segmented outer rotor core is the pole opening width B 极口 , 0.8*B 极口 ≤B7≤1.2*B 极 .

[0008] In some embodiments, the included angle between the two legs of the isosceles trapezoid is ∠b, 20°<∠b<60°; and / or, the height of the isosceles trapezoid is L2, L2<1.2mm.

[0009] In some embodiments, the core radial outer side surface and the core radial inner side surface of the core punching sheet can be matched and fitted, and the core radial inner side surface and the core radial outer side surface of the core punching sheet are formed by a cutting seam.

[0010] In some embodiments, the radial inner end of the punching sheet body has an inner side magnet block extending to both sides of the core punching sheet along the circumferential direction of the segmented outer rotor core, the inner side surface of the inner side magnet block and the radial inner side surface of the punching sheet body jointly form the core radial inner side surface, the projection of the core punching sheet on any radial plane of the segmented outer rotor core also includes an inner side straight line segment at both ends of the inner side circular arc segment in the circumferential direction, the inner side straight line segment is perpendicular to the first central symmetry plane, the radius of the inner side circular arc segment is R 内 , the pole number of the segmented outer rotor core is 2p, the circumferential distance between the inner side magnet blocks of the adjacent two core punching sheets is the pole opening width B 极口 , the distance between the inner side straight line segment and the center of the segmented outer rotor core is the tangent angle height h 切角 ,

[0011] In some embodiments, the length of the inner side straight line segment is L3, and the maximum distance between the inner side magnet blocks on both sides of the same core punching sheet is B2,

[0012] In some embodiments, the radially outer end of the punch body has outer side magnet blocks extending to both sides of the core punch along the circumferential direction of the segmented outer rotor core, the radially outer side surface of the outer side magnet blocks and the radially outer side surface of the punch body jointly form the radially outer side surface of the core, the side surface of the outer side magnet blocks towards the inner side magnet blocks is a first plane, the side surface of the inner side magnet blocks towards the outer side magnet blocks is a second plane, the first plane and the second plane on the same circumferential side of the punch body are parallel, and the first plane is not perpendicular to the first center symmetry plane, the magnet steel slot has a second center symmetry plane in the diameter direction of the segmented outer rotor core, and any two adjacent core punches each have a first plane and a second plane corresponding to the magnet steel slot, which are both perpendicular to the second center symmetry plane.

[0013] In some embodiments, the radially outer end of the punch body has outer side magnet blocks extending to both sides of the core punch along the circumferential direction of the segmented outer rotor core, the radially outer side surface of the outer side magnet blocks and the radially outer side surface of the punch body jointly form the radially outer side surface of the core, the side surface of the outer side magnet blocks towards the inner side magnet blocks is a first plane, the side surface of the inner side magnet blocks towards the outer side magnet blocks is a second plane, the first plane and the second plane on the same circumferential side of the punch body are parallel, and the first plane is not perpendicular to the first center symmetry plane, the magnet steel slot has a second center symmetry plane in the diameter direction of the segmented outer rotor core, and any two adjacent core punches each have a first plane and a second plane corresponding to the magnet steel slot, which are both perpendicular to the second center symmetry plane.

[0014] In some embodiments, the radially outer side surface of the core has process grooves, in the layout state of each core punch, one of the two adjacent core punches has each process groove corresponding to each auxiliary groove of the other core punch, the two side walls of each process groove are in the same straight line with the groove walls of the auxiliary groove corresponding to the position of the process groove, and the groove depth of the process groove is greater than the chamfer radius of the groove bottom.

[0015] The application also provides a rotor assembly comprising the segmented outer rotor core described above, the magnet steel slot is assembled with tangential magnet steel, and the polarities of the opposite sides of two adjacent tangential magnet steels are opposite.

[0016] The application also provides an outer rotor motor comprising the rotor assembly described above.

[0017] The segmented outer rotor core, the rotor assembly and the outer rotor motor provided by the application have the following beneficial effects:

[0018] The outer rotor core has a block structure. There is no magnetic bridge connecting the two adjacent core segments, and there is basically no leakage magnetic path. This greatly reduces the leakage magnetic field of the motor and improves the motor performance. On this basis, auxiliary slots are provided on the radial inner side of the core to effectively reduce the motor cogging torque. The auxiliary slots increase the number of fundamental wave cycles of the cogging torque, thereby reducing the cogging torque amplitude. At the same time, the equivalent air gap is appropriately increased, which is also conducive to reducing the cogging torque.

[0019] By limiting the relative positions of the two auxiliary slots and the correlation between the circumferential width of the slot opening and the relevant parts, it is ensured that the two auxiliary slots are symmetrically distributed about the central symmetric position of the punching sheet body, the outer slot walls of the two auxiliary slots do not exceed the circumferential width range of the punching sheet body, and the spacing between the inner slot walls of the two auxiliary slots is not less than the slot width of each auxiliary slot, thereby avoiding the phenomenon of local magnetic saturation after the auxiliary slots are opened in the rotor core;

[0020] Since the shapes and sizes of the radial inner side surfaces and the radial outer side surfaces of the core punching sheets are identical and match each other, when the core punching sheets are arranged and punched, multiple core punching sheets can be arranged closely along the inner and outer length directions of the core punching sheets, that is, the radial inner side surface of the core of one core punching sheet and the radial outer side surface of the core of another adjacent core punching sheet can be formed by punching a seam, that is, the structural design of the core punching sheets in the present invention realizes the close arrangement of the side surfaces of at least two adjacent core punching sheets in one direction, and there is no overlap in this area, so no waste is generated in this area during the punching process, thereby greatly improving the material utilization rate of the silicon steel sheet and reducing the waste rate;

[0021] Through h 切角 The relationship between the radius of the inner arc segment, the number of motor poles, and the pole opening width is limited, which can further reduce the torque pulsation of the corresponding motor;

[0022] By designing the planes of the magnetic blocks on the radial inner and outer sides of the core punching sheets to be parallel to each other, and forming an angle setting (vertical or non-vertical) with the first central symmetry plane and the second central symmetry plane, it is possible to make it possible to turn the adjacent core punching sheets upside down 180° along the left and right directions and arrange them left and right when arranging the punching sheets, forming a parallelogram-shaped cut between the two, ensuring the plane formation of the aforementioned first plane and the second plane, and no sharp corners remaining after punching, so as to support the radial inner and radial outer ends of the tangential magnetic steel, ensure the position reliability and stability of the tangential magnetic steel during the operation of the motor, and at the same time reduce the difficulty of punching. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed in the description of the embodiments or the prior art. The drawings in the following description are merely exemplary, and for those skilled in the art, other drawings can be derived from the provided drawings without creative labor.

[0024] Figure 1 is a block-type inner rotor core punching layout schematic diagram in the prior art;

[0025] Figure 2 is a structure schematic diagram of a block-type outer rotor core in a circular state (radial plane projection view) of the embodiment of the present application;

[0026] Figure 3 is a structure schematic diagram of a core sub-body in Figure 2 ;

[0027] Figure 4 is a core sub-body punching layout schematic diagram in the present application (i.e. in a layout state);

[0028] Figure 5 is a partial structure schematic diagram of an outer rotor motor of the embodiment of the present application (radial plane projection view);

[0029] Figure 6 is a torque fluctuation (i.e. torque ripple) comparison schematic diagram of a motor using the corner cutting structure and auxiliary slot in the present application and a motor not using the corner cutting structure and auxiliary slot in the present application.

[0030] The reference signs are:

[0031] 11, core punching; 111, punching body; 1111, inner side circular arc segment; 1112, inner side straight line segment; 1113, outer side circular arc segment; 1114, outer side straight line segment; 112, inner side magnet stop block; 113, outer side magnet stop block; 12, magnet slot; 131, plastic wrapping connecting hole; 132, positioning hole; 14, auxiliary slot; 15, process groove; 2, tangential magnet; 3, stator core. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way limiting of the application or its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0033] In the description of the application, it needs to be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the application and simplifying the description, and do not indicate and imply that the devices or elements referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the scope of protection of the application; the orientation words "inner, outer" refer to the inner and outer of the contour of each component itself.

[0034] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial positional relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the devices described in the drawings. For example, if the devices in the drawings are inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0035] In addition, it should be noted that the use of the words "first", "second" and the like to define parts is only for the convenience of distinguishing the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0036] For reference Figures 2 to 6 As shown, according to the embodiment of the application, a split outer rotor core is provided, which comprises a plurality of core segments (i.e. each core segment is in a circular state) uniformly spaced around the center axis of the split outer rotor core and stacked by a plurality of core punching sheets 11, a magnetic steel slot 12 is formed between two adjacent core segments, a tangential magnetic steel 2 (e.g. a permanent magnet) is assembled in the magnetic steel slot 12, an auxiliary slot 14 is formed on the core radial inner side surface (i.e. the side surface that forms an air gap with the stator core 3, not labeled in the figure) of the core punching sheet 11, and the auxiliary slot 14 is recessed from inside to outside along the diameter direction of the split outer rotor core.

[0037] In this technical solution, the outer rotor core has a block structure. There is no magnetic bridge connection between the two adjacent core segments, and there is basically no leakage magnetic path, which greatly reduces the leakage magnetic field of the motor and improves the performance of the motor. On this basis, an auxiliary slot 14 is provided on the radial inner side surface of the core, which can effectively reduce the cogging torque of the motor.

[0038] See Figure 3 As shown, in some embodiments, each of the core punching sheets 11 has a first central symmetric plane (not marked in the figure) in the diameter direction of the segmented outer rotor core, and the core punching sheet 11 includes a punching sheet body 111, and the core punching sheet 11 is projected on any radial surface of the segmented outer rotor core. The circumferential width of the punching sheet body 111 is B3, and two auxiliary slots 14 are provided on the radial inner side of the core. The two auxiliary slots 14 are symmetrical about the first central symmetric plane, and the center angle formed by the slot center lines of the two auxiliary slots 14 and the center of the segmented outer rotor core is ∠a. The projection of the radial inner side of the core includes an inner arc segment 1111, and the radius of the inner arc segment 1111 is R 内 The circumferential width of each auxiliary groove 14 is B7.

[0039] In this technical solution, by limiting the relative positions of the two auxiliary slots 14 and the correlation between the circumferential width of the slot and the relevant parts, it is ensured that the two auxiliary slots 14 are symmetrically distributed about the central symmetrical position of the punching sheet body 111, the outer slot walls of the two auxiliary slots 14 do not exceed the circumferential width range of the punching sheet body 111, and the spacing between the inner slot walls of the two auxiliary slots 14 is not less than the slot width of each auxiliary slot 14, thereby avoiding the phenomenon of local magnetic saturation after the auxiliary slots 14 are opened in the rotor core.

[0040] In some embodiments, the auxiliary slot 14 is shaped like an isosceles trapezoid, and the lower base of the isosceles trapezoid is close to the center of the block-type outer rotor core. The lower base is also the long base of the isosceles trapezoid, that is, the auxiliary slot 14 of the present invention is a flared structure with a gradually wider width toward the outside of the core punching 11. In a preferred embodiment, the width of the slot of the magnetic steel slot 12 close to the center of the block-type outer rotor core is the pole opening width B. 极口 , 0.8*B 极口 ≤B7≤1.2*B 极口 The angle formed between the two waist sides of the isosceles trapezoid is ∠b, 20°<∠b<60°, the height of the isosceles trapezoid is L2, L2<1.2mm, and the auxiliary slot 14 opened in this way increases the fundamental wave period of the cogging torque, thereby reducing the amplitude of the cogging torque, and at the same time appropriately increases the equivalent air gap, which is also beneficial to reducing the cogging torque.

[0041] See also Figure 2 and Figure 4 As shown, in some embodiments, the radial outer side surface of the core punching sheet 11 and the radial inner side surface of the core can match and fit together. When each of the core punching sheets 11 is in the arrangement state, the radial inner side surface of the core and the radial outer side surface of the core of the core punching sheet 11 are formed by punching and dividing by a cutting seam. At this time, it can be understood that the radial inner side surface of the core and the radial outer side surface of the core of the core punching sheet 11 are the same in shape and size. Since each core split is formed by stacking the same core punching sheet 11, when projected on the radial surface of the block-type outer rotor core, the shape of each core split is the same as the shape and size of each core punching sheet 11.

[0042] In this technical solution, since the radial inner side surface and the radial outer side surface of the core punching sheet 11 are of the same shape and size to form a matching fit, when the core punching sheet 11 is arranged and punched, multiple core punching sheets 11 can be arranged closely along the inner and outer length directions of the core punching sheet 11, that is, the radial inner side surface of the core of one core punching sheet 11 and the radial outer side surface of the core of another adjacent core punching sheet 11 can be formed by punching a seam, that is, the structural design of the core punching sheet 11 in the present invention realizes the close arrangement of the sides of at least two adjacent core punching sheets 11 in one direction, and there is no overlap in this area, so no waste will be generated in this area during the punching process, thereby greatly improving the material utilization rate of the silicon steel sheet and reducing the waste rate. For comparison, see Figure 1 As shown in the punching arrangement diagram of the traditional block-type inner rotor core, there are overlaps between adjacent rotor punching units (lap 1, overlap 2 and overlap 3 in the figure), which increases the scrap rate of silicon steel sheet material and the material utilization rate needs to be further improved. The above-mentioned design of the present invention can overcome the shortcomings of the existing technology.

[0043] For further details, see Figure 4 As shown, Figure 4 The shown orientation is for reference only. The radial inner side surface of the core of the upper core punching sheet 11 and the radial outer side surface of the core of the lower and adjacent core punching sheet 11 are directly in close contact with each other, that is, they are formed by cutting a shaped gap on an integral silicon steel sheet, and almost no waste is generated.

[0044] In some embodiments, the radial inner end of the punching body 111 has an inner magnetic stopper 112 extending along the circumference of the segmented outer rotor core to both sides of the core punching sheet 11. Specifically, the inner magnetic stopper 112 and the punching body 111 are punched and formed as one piece, and the radial outer side surfaces of the two inner magnetic stoppers 112 adjacent to the two adjacent core punching sheets 11 jointly form a reliable limit for the radial inner end of the tangential magnetic steel 2. For details, seeFigure 3 As shown, the radially inner side of the inner magnet block 112 and the radially inner side of the core body 111 jointly form the radially inner side of the core, the projection of the core core sheet 11 on any radial plane of the split outer rotor core, the projection of the radially inner side of the core also includes the inner straight section 1112 at the circumferential two ends of the inner arc section 1111, the inner straight section 1112 is perpendicular to the first central symmetry plane, it should be noted that the aforementioned inner straight section 1112 is objectively also the tangent corner structure at the circumferential two ends of the radially inner side of the core, the radius of the inner arc section 1111 is R 内 (the center is away from the radially outer side of the core), the pole number of the split outer rotor core is 2p, the circumferential distance between the inner magnet blocks 112 of the adjacent two core core sheets 11 is the pole opening width B 极口 , the distance between the inner straight section 1112 and the center of the split outer rotor core is the tangent corner height h 切角 , It can be understood that when h 切角 <cos(π / 2p)*R 内 +sin(π / 2p)*B 极口 / 2, the aforementioned radially inner side of the core objectively has no tangent corner structure, and h 切角 >R 内 , that is, the inner circular surface is completely tangent and the air gap is increased, which is not practical.

[0045] In this technical solution, by limiting the relationship between h 切角 , the radius of the aforementioned inner arc section 1111, the number of motor poles and the pole opening width, the torque ripple of the corresponding motor can be further reduced.

[0046] In some embodiments, the length of the inner straight section 1112 is L3, and the maximum distance between the inner magnet blocks 112 on both sides of the same core core sheet 11 is B2, so as to further reduce the torque ripple during motor operation.

[0047] Referring to Figure 6 As shown, it can be seen from the figure that the torque ripple of the motor using the aforementioned tangent corner structure and auxiliary slot of the application is 1.03%, and the torque ripple of the motor without using the aforementioned tangent corner structure and auxiliary slot of the application is 8.91%, that is, the torque ripple is reduced by nearly 88% after setting the tangent corner structure and auxiliary slot.

[0048] In some embodiments, the radially outer end of the punch body 111 has outer side magnet blocks 113 extending to both sides of the core punch 11 along the circumference of the segmented outer rotor core, the radially outer side of the outer side magnet blocks 113 and the radially outer side of the punch body 111 together form the radially outer side of the core, it can be understood that since the radially inner side of the core and the radially outer side of the core are completely consistent in shape and size, the projection of the radially outer side of the core on the radial plane at this time includes an outer side arc segment 1113 and outer side straight line segments 1114 at both ends thereof, wherein the outer side arc segment 1113 is the same in shape and size as the inner side arc segment 1111, and the outer side straight line segments 1114 are the same in shape and size as the inner side straight line segments 1112, the side of the outer side magnet blocks 113 facing the inner side magnet blocks 112 is a first plane (i.e. the lower side of the outer side magnet blocks 113 shown in the figure), the side of the inner side magnet blocks 112 facing the outer side magnet blocks 113 is a second plane (i.e. the upper side of the inner side magnet blocks 112 shown in the figure), the first plane and the second plane on the same circumferential side of the punch body 111 are parallel, and the first plane is not perpendicular to the first center symmetry plane (i.e. forms an included angle), the magnet slot 12 has a second center symmetry plane (not labeled in the figure) in the diameter direction of the segmented outer rotor core, and any two adjacent core punches 11 each have a first plane and a second plane corresponding to the magnet slot 12, which are perpendicular to the second center symmetry plane. It can be understood that the center of the aforementioned outer side arc segment 1113 and the center of the inner side arc segment 1111 are on the same diameter of the outer rotor core, and the distance L1 between the two circles is equal to the radial length of the punch body 111. The maximum distance between the outer side magnet blocks 113 on both sides of the same core punch 11 is B1, and B1=B2. Figure 3 Figure 3

[0049] In this technical solution, by designing the planes of the magnet blocks on the radially inner and outer sides of the core punch 11 opposite to each other in a parallel manner, and forming an angle (perpendicular or not perpendicular) with the first center symmetry plane and the second center symmetry plane, it can be ensured that when the punch layout is performed, the adjacent core punches 11 can be arranged left and right after being inverted 180° up and down along the left-right direction in the orientation shown in Figure 4

[0050] ​​​In some embodiments, the radial width of the free end face of the inner magnet stop block 112 is B4, and the radial width of the free end face of the outer magnet stop block 113 is B5, B4=B5, and the thickness of the two magnet stops close to each other is equal, so that the shape of the silicon steel sheet area punched out by the punch is more regular, which can reduce the special requirements for the punch structure and reduce the punching cost. The angle formed between the free end faces of the two inner magnet stops 112 of the same core punching sheet 11 is equal to the angle formed between the free end faces of the two outer magnet stops 113, both of which are 360° / 2p, and 2p is the number of poles of the segmented outer rotor core.

[0051] In some embodiments, the projection of the magnetic steel slot 12 on the radial surface of the segmented outer rotor core is an isosceles trapezoid, and the upper base of the isosceles trapezoid is located radially inside the lower base. It can be understood that the shape of the corresponding tangential magnetic steel 2 matches the magnetic steel slot 12, which can reduce the difficulty of processing the tangential magnetic steel 2.

[0052] In some embodiments, the core has a process groove 15 on its radial outer side. When the core punches 11 are in the arrangement state, the position of the process grooves 15 of one of the two adjacent core punches 11 corresponds to the auxiliary grooves 14 of the other one. The groove walls on both sides of each process groove 15 are on the same straight line as the groove walls of the auxiliary grooves 14 corresponding to their positions. The groove depth of the process groove 15 is greater than the fillet radius of its groove bottom, so as to avoid sharp corner waste caused by rounded corners (rounded corners of the punch itself) when punching the auxiliary grooves 14 close to the arrangement. For details, see Figure 3 As shown, in order to ensure that the groove walls on both sides of each process groove 15 are in the same straight line with the groove walls of the auxiliary groove 14 corresponding to its position, the groove width B6 of each process groove 15 is equal to B7, and the shape of each process groove 15 is also an isosceles trapezoid, and the upper base of the isosceles trapezoid corresponds to the lower base of the auxiliary groove 14, and the angle ∠c formed by the two waists of the isosceles trapezoid of the process groove 15 is equal to ∠b. Of course, the number of process grooves 15 is set to two.

[0053] In some embodiments, the core punching sheet 11 has a positioning hole 132 that passes through both end surfaces thereof. The positioning hole 132 can limit the circumferential rotation of the core punching sheet 11. For details, see Figure 2As shown, the aforementioned positioning hole 132 can be a square hole, and in the process of manufacturing the rotor core, the accurate determination of the position of each core segment can be achieved by the plurality of square columns arranged along the circumference in the corresponding positioning mold, that is, the stability of the circular state between each core segment is ensured, and then the plastic packaging process can be performed on each core segment in the circular state. Of course, before the specific plastic packaging, each tangential magnetic steel 2 should be assembled in the corresponding magnetic steel slot 12, so as to realize the integrated plastic packaging of the outer rotor core.

[0054] In order to further ensure the structural stability and reliability of the manufactured outer rotor core, prevent the separation between the plastic packaging material and the core segment, each of the core punching sheets 11 has a plastic packaging connecting hole 131 penetrating through the two side end faces thereof. During the plastic packaging process, the plastic packaging material will have a part in the plastic packaging connecting hole 131, and a frame structure with a plurality of plastic packaging columns in the middle of the plastic packaging end plates formed at both ends is formed, and the structure is more stable.

[0055] According to the embodiments of the present application, a rotor assembly is also provided, which comprises the aforementioned segmented outer rotor core, the magnetic steel slot 12 is assembled with the tangential magnetic steel 2, and the polarities of the opposite sides of the adjacent two tangential magnetic steels 2 are opposite. See Figure 6 As shown, the magnetization direction of each tangential magnetic steel 2 is along the tangential direction of the rotor, and the polarities of the circumferential sides of the adjacent two tangential magnetic steels 2 are one of N-pole and S-pole, respectively. The rotor core has positive and negative alternating polarities in the circumferential direction, and the torque is generated by the interaction with the stator core 3.

[0056] According to the embodiments of the present application, an outer rotor motor is also provided, which comprises the aforementioned rotor assembly.

[0057] It is easy for those skilled in the art to understand that the advantageous technical features of each of the above-mentioned modes can be freely combined and superimposed without conflict.

[0058] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above only describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications shall be regarded as the protection scope of the present application.

Claims

1. A block-type outer rotor core, characterized in that: The invention comprises a plurality of core segments evenly spaced around the central axis of the block-type outer rotor core and stacked by a plurality of core punching sheets (11), a magnetic steel slot (12) being formed between two adjacent core segments, an auxiliary slot (14) being formed on the radial inner side surface of the core of the core punching sheet (11), the auxiliary slot (14) being recessed from the inside to the outside along the diameter direction of the block-type outer rotor core; each core punching sheet (11) has a first central symmetric plane in the diameter direction of the block-type outer rotor core, the core punching sheet (11) comprising a punching sheet body ( 111), the core punching sheet (11) is projected on any radial surface of the block-type outer rotor core, the circumferential width of the punching sheet body (111) is B3, two auxiliary slots (14) are provided on the radial inner side surface of the core, the two auxiliary slots (14) are symmetrical about the first central symmetry plane, and the central angle formed by the slot center lines of the two auxiliary slots (14) and the center of the block-type outer rotor core is ∠a, the projection of the radial inner side surface of the core includes an inner arc segment (1111), and the radius of the inner arc segment (1111) is R 内 The circumferential width of each auxiliary groove (14) is B7. and 2. The segmented outer rotor core according to claim 1, characterized in that: The auxiliary slot (14) is in the shape of an isosceles trapezoid, and the lower base of the isosceles trapezoid is close to the center of the block-type outer rotor core; and / or the width of the slot opening of the magnetic steel slot (12) close to the center of the block-type outer rotor core is the pole opening width B. 极口 , 0.8*B 极口 ≤B7≤1.2*B 极口 .

3. The segmented outer rotor core according to claim 2, characterized in that: The angle formed between the two waist sides of the isosceles trapezoid is ∠b, 20°<∠b<60°; and / or the height of the isosceles trapezoid is L2, L2<1.2 mm.

4. The segmented outer rotor core according to claim 2 or 3, characterized in that: The radial outer side surface of the core punching sheet (11) and the radial inner side surface of the core punching sheet (11) can match and coincide with each other. When each core punching sheet (11) is in an arrangement state, the radial inner side surface of the core punching sheet (11) and the radial outer side surface of the core punching sheet (11) are formed by punching and dividing by a cutting seam.

5. The segmented outer rotor core according to claim 4, characterized in that: The radial inner end of the punch body (111) has an inner magnetic stopper (112) extending along the circumference of the segmented outer rotor core toward both sides of the core punch (11); the radial inner side surface of the inner magnetic stopper (112) and the radial inner side surface of the punch body (111) together form the radial inner side surface of the core; the core punch (11) is projected onto any radial surface of the segmented outer rotor core; the projection of the radial inner side surface of the core also includes inner straight line segments (1112) at both circumferential ends of the inner arc segment (1111); the inner straight line segments (1112) are perpendicular to the first central symmetry plane; the radius of the inner arc segment (1111) is R 内 The number of poles of the block-type outer rotor core is 2p, and the circumferential spacing between the inner magnetic stoppers (112) respectively provided by two adjacent core punching sheets (11) is the pole opening width B. 极口 The distance between the inner straight line segment (1112) and the center of the segmented outer rotor core is the cutting angle height h 切角 , 6. The segmented outer rotor core according to claim 5, characterized in that: The length of the inner straight line segment (1112) is L3, the maximum distance between the inner magnetic stoppers (112) on both sides of the same core punching sheet (11) is B2, 7. The segmented outer rotor core according to claim 6, characterized in that: The radial outer end of the punch body (111) has an outer magnetic stopper (113) extending along the circumference of the segmented outer rotor core toward both sides of the core punch (11); the radial outer side surface of the outer magnetic stopper (113) and the radial outer side surface of the punch body (111) together form the radial outer side surface of the core; the side surface of the outer magnetic stopper (113) facing the inner magnetic stopper (112) is a first plane; the side surface of the inner magnetic stopper (112) facing the outer magnetic stopper (113) is a second plane; the first plane and the second plane on the same circumferential side surface of the punch body (111) are parallel, and the first plane is not perpendicular to the first central symmetry plane; the magnetic steel slot (12) has a second central symmetry plane in the diameter direction of the segmented outer rotor core; the first plane and the second plane corresponding to the magnetic steel slot (12) of any two adjacent core punches (11) are both perpendicular to the second central symmetry plane.

8. The segmented outer rotor core according to claim 7, characterized in that: The radial width of the free end face of the inner magnetic stopper (112) is B4, the radial width of the free end face of the outer magnetic stopper (113) is B5, B4=B5, and the angle formed between the free end faces of the two inner magnetic stoppers (112) of the same core punching sheet (11) is equal to the angle formed between the free end faces of the two outer magnetic stoppers (113), both being 360° / 2p, where 2p is the number of poles of the segmented outer rotor core.

9. The segmented outer rotor core according to claim 4, characterized in that: The iron core has a process groove (15) on its radial outer surface. When the iron core punching sheets (11) are in an arrangement state, the position of each process groove (15) of one of the two adjacent iron core punching sheets (11) corresponds to each auxiliary groove (14) of the other one. The groove walls on both sides of each process groove (15) are on the same straight line as the groove walls of the auxiliary groove (14) corresponding to the position thereof, and the groove depth of the process groove (15) is greater than the fillet radius of its groove bottom.

10. A rotor assembly, characterized in that: The invention comprises a segmented outer rotor core according to any one of claims 1 to 9, wherein tangential magnetic steels (2) are assembled in the magnetic steel slots (12), and the polarities of opposite sides of two adjacent tangential magnetic steels (2) are opposite.

11. An outer rotor motor, characterized in that: The invention comprises the rotor assembly as claimed in claim 10.

Images