Rotor for brushless motor and brushless motor including same

Abstract

The utility model relates to a rotor used for a brushless motor, the rotor comprises a rotating shaft with a rotation axis, a rotor iron core sleeved outside the rotating shaft, and a molding member which is formed by integral injection molding around the rotating shaft, and the rotating shaft, the rotor iron core and the molding member can rotate around the rotation axis together. A plurality of magnetic steel grooves for accommodating magnetic steel are arranged in the rotor iron core, and the plurality of magnetic steel grooves and the magnetic steel accommodated in the magnetic steel grooves surround the rotating shaft and penetrate through the rotor iron core along the axial direction parallel to the extension direction of the rotating axis. Wherein the molded part wraps two end surfaces of the rotor core in the axial direction, and one end part of the rotating shaft in the axial direction and / or the rotor core are / is provided with a positioning feature part used for injection molding and / or magnetizing. The utility model also relates to a brushless motor comprising the rotor.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technical field, concretely relates to a rotor for brushless motor and including the rotor of brushless motor. BACKGROUND

[0002] Motor is a kind of electromagnetic device to realize electric energy conversion or transmission according to electromagnetic induction law, and it provides power for various electric appliances or machinery after being electrified as driving component. Among them, motor rotor is mainly composed of shaft, rotor core and magnetic steel, and plastic encapsulation layer is arranged on the outer ring of rotor, for fixing rotor core. Especially, in the current market design of embedded permanent magnet brushless motor, it is usually necessary to use glue to fix magnetic steel and install fan or gasket (material such as plastic or copper) on the axial ends of rotor core, wherein the glue is used to fix the magnetic steel so that it does not displace in the radial direction relative to the rotor core, and the fan or gasket is used to prevent the magnetic steel from not displacing in the axial direction relative to the rotor core. After the production of rotor is completed, dynamic balance adjustment is also needed. However, for the brushless motor rotor fixed by plastic gasket, the weight of plastic is too light to do rotor dynamic balance, resulting in vibration and noise problems of rotor in high-speed operation. For the brushless motor rotor fixed by copper gasket, although the copper gasket at both ends of rotor core is removed to achieve the required balance of rotor, the manufacturing cost of copper gasket is relatively high. In addition, the above-mentioned interference connection and rotor shaft fixation of gasket at both ends of rotor core have higher requirements for production process and rotor core flatness movement. In the case of plastic gasket, the magnet is easily disengaged and the plastic end is easily pushed out due to the failure of glue at high temperature. In the case of copper gasket, if the rotor part precision is poor, the copper gasket and rotor core press fit are easy to crush the magnet.

[0003] It should be noted that the "background" section is only used to help understand the content of the utility model, so the content disclosed in the "background" section may include some prior art that is not known to those skilled in the art. The content disclosed in the "background" section does not represent the problems to be solved by the content or one or more embodiments of the utility model, which have been known or recognized by those skilled in the art before the utility model application. UTILITY MODEL CONTENT

[0004] In view of the problems in the prior art, the utility model aims to provide a one-piece injection molded rotor, which can ensure the mechanical strength of the rotor and reduce the magnetic flux leakage of the motor to maintain the basic electrical performance of the rotor, while facilitating dynamic balance to meet the balance requirements of the rotor.

[0005] According to one aspect of the present application, a rotor for a brushless motor is provided, the rotor comprising a rotor shaft having a rotation axis, a rotor core sleeved on the rotor shaft, and a molded member integrally molded around the rotor shaft, the rotor shaft, the rotor core and the molded member being rotatable together around the rotation axis, the rotor core being provided with a plurality of magnetic steel grooves for accommodating magnetic steels, the plurality of magnetic steel grooves together with the magnetic steels accommodated therein extend around the rotor shaft and through the rotor core along an axial direction parallel to the extension direction of the rotation axis, wherein the molded member covers two end faces of the rotor core in the axial direction, and a positioning feature for injection molding and / or magnetization is provided on one of the end portions of the rotor shaft in the axial direction and / or on the rotor core.

[0006] Preferably, the rotor core has a rotor shaft hole at a central position for receiving the rotor shaft, and recesses recessed towards the rotor core along the radial direction of the rotor shaft are uniformly formed on the peripheral wall of the rotor shaft hole.

[0007] Preferably, as viewed in a cross section perpendicular to the rotation axis, the plurality of magnetic steel grooves are uniformly arranged around the rotor shaft hole in the form of a regular polyhedron, and a magnetic bridge reinforcing rib is provided between adjacent magnetic steel grooves.

[0008] Preferably, the positioning feature provided on the end portion of the rotor shaft is a flat cutout portion, which extends parallel to one of the magnetic steel grooves as viewed in the direction extending from the rotation axis.

[0009] Preferably, the positioning feature provided on the rotor core is at least two positioning holes, each of which is on the perpendicular line from the center of the rotor shaft hole to the corresponding magnetic steel groove as viewed in the cross section perpendicular to the rotation axis.

[0010] Preferably, the positioning holes are symmetrically arranged in pairs about the center of the rotor shaft hole.

[0011] Preferably, the molded member is formed with positioning holes aligned with the positioning holes provided on the rotor core during the integral injection molding process.

[0012] Optionally, as viewed in a cross section perpendicular to the rotation axis, the plurality of magnetic steel grooves are uniformly arranged around the rotor shaft hole, and each magnetic steel groove is arranged in a manner that one end thereof faces the rotor shaft hole and the other end thereof extends radially outward, so that each two adjacent magnetic steel grooves define a sector-shaped rotor core segment, and each rotor core segment is distributed in a ring shape around the rotor shaft hole.

[0013] Optionally, the positioning features provided on the rotor core are at least two positioning holes, which are provided in pairs in rotor core blocks symmetrically distributed about the center of the rotation shaft hole.

[0014] Optionally, the cross-sectional shape of the positioning holes gradually narrows from a portion further out in the radial direction of the rotor core toward a portion closer to the rotation shaft hole in the radial direction, as viewed in a cross section perpendicular to the rotation axis.

[0015] Optionally, the molded part is formed with positioning holes aligned with the positioning holes provided on the rotor core in the process of integral injection molding.

[0016] Preferably, a rib or knurl extending in the axial direction is provided on the outer periphery of the rotation shaft, which extends beyond the molded part in the axial direction.

[0017] According to another aspect of the present application, a brushless motor is provided, which includes the rotor according to the foregoing.

[0018] Further features and advantages of the present application will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0019] The above and other aspects of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

[0020] Figure 1 A perspective view of a rotor according to a preferred embodiment of the present application is shown;

[0021] Figure 2a A cross-sectional view of a rotor core of a rotor according to the present application, taken in a direction perpendicular to the rotation axis of the rotation shaft, is shown;

[0022] Figure 2b A cross-sectional view of a rotor core of a rotor according to the present application, taken in a direction perpendicular to the rotation axis of the rotation shaft, is shown;

[0023] Figure 3 A molded part portion of a rotor according to the present application after injection molding is shown;

[0024] Figure 4 A perspective view of a semi-finished product formed by press-fitting the rotation shaft of the rotor of the present application into the rotation shaft hole of the rotor core is shown, in which the positioning features provided on the rotation shaft and the rotor core, respectively, are shown.

[0025] Figure 5 The rotor according to the present application is shown in a cross-sectional view perpendicular to the rotational axis of the rotor shaft after further combination with the stator of a brushless motor, and the magnetic field lines of the rotor magnetic field obtained thereby. DETAILED DESCRIPTION

[0026] In order to make the objects, features and advantages of the present application more apparent, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. It should be noted that the use of "first", "second", and the like in the description and the claims of the present application is used to distinguish similar objects, and does not necessarily indicate a specific order or sequence. Unless otherwise specified, the relative arrangement, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the description of the present application is only for the purpose of describing the specific embodiments, and is not intended to limit the present application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. In addition, techniques and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the specification where appropriate.

[0028] Figure 1 A perspective view of a rotor 1 for a brushless motor according to the present application is shown. As shown, the rotor 1 includes a rotor shaft 10 having a rotational axis (shown as a dotted line in the figure), a rotor core 20 fitted on the rotor shaft 10, and a molded member 30 integrally molded around the rotor shaft 10, the rotor shaft 10, the rotor core 20, and the molded member 30 being rotatable together about the rotational axis, wherein the molded member 30 covers two end faces of the rotor core 20 in the extension direction (i.e., the axial direction) along the rotational axis.

[0029] Further combination Figure 2a which shows Figure 1 A cross-sectional view of the rotor core 20 of the rotor in the embodiment, taken in a direction perpendicular to the rotational axis of the rotor shaft 10. It should be noted that in practice, the rotor core 20 is formed by stacking a plurality of identical rotor core sheets, and thus the cross-sectional view obtained by each rotor core sheet in a cross-section perpendicular to the rotational axis of the rotor shaft 10 is similar to Figure 2aThe rotor core 20 is generally cylindrical, and has a rotor shaft hole 201 in the center for receiving the rotor shaft 10. In order to facilitate the press-fitting of the processed rotor shaft 10 into the rotor shaft hole 201 of the laminated rotor core 20, recesses 202 are formed on the peripheral wall of the rotor shaft hole 201, which are recessed towards the rotor core 20 along the radial direction of the rotor shaft 10 (four recesses 202 are shown in the figure, and those skilled in the art can envisage that the number and position of the recesses 202 can be set as required). Further, a magnetic steel slot 203 is formed inside the rotor core 20, which is in the form of a straight line and is uniformly arranged around the rotor shaft hole 201 of the rotor core 20 (four magnetic steel slots 203 are shown in the figure, arranged in the form of a square). In the assembled rotor core 20, each magnetic steel slot 203 receives a corresponding magnetic steel, and the magnetic steel, after being magnetized, can generate a corresponding magnetic field in and around the rotor core 20.

[0030] The rotor according to the present application can be integrally formed through an injection molding process, and the forming process is as follows.

[0031] First, the rotor shaft 10 and the rotor core 20 are respectively processed, the non-magnetized magnetic steels are respectively inserted into the corresponding magnetic steel slots 203 of the rotor core 20, and the rotor shaft 10 is pressed through the rotor shaft hole 201 of the rotor core 20. It should be noted that the rotor shaft 10 and the rotor shaft hole 201 are in interference fit so that the rotor shaft 10 can drive the rotor core 20 to rotate together without relative movement between them. Further referring to Figure 1 It can be seen that the flange 103 is provided on the rotor shaft 10, and after press-fitting, the flange 103 protrudes from the axial end surface of the rotor core 20 by a predetermined distance, which corresponds to the thickness of the molded part 30 formed after injection molding and protruding from the axial end surface of the rotor core 20. In this way, the axial positions of the rotor shaft 10 and the rotor core 20 can be determined.

[0032] Next, the assembled rotor shaft 10 and the semi-finished rotor core 20 are placed in a mold (not shown) for the injection molding process, and the mold is used to ensure the positions of the rotor shaft 10, the rotor core 20 and the magnetic steels are fixed. Then, the molding material (for example, BMC in this embodiment) is injected into the mold to fill the gaps between the rotor components, thereby forming the above-mentioned molded part 30. Referring to Figure 3It is shown that the rotor is injection molded, and the mold part 30 is removed after the shaft 10 and the rotor core 20. As can be seen from the figure, the mold part 30 not only realizes the axial fixation of each magnetic steel in the corresponding magnetic steel slot by cladding the end surface of the rotor core along the shaft axis, but also realizes the same function of fixing the magnetic steel with glue in the traditional manufacturing process of the rotor core during the molding process because the molding material fills the gap between the magnetic steel and the magnetic steel slot. Therefore, it is ensured that each magnetic steel in the corresponding magnetic steel slot has no relative displacement in the axial and radial directions.

[0033] Then, the rotor after injection molding is placed in the magnetizer, so that the corresponding number of excitation coils in the magnetizer are respectively aligned with the magnetic steels in the magnetic steel slots, and the excitation coils complete the magnetization of the magnetic steels under the condition of being energized.

[0034] Finally, the magnetized rotor is taken out of the magnetizer, and dynamic balance operation is performed thereon. It can be understood that the part of the mold part 30 cladding the axial end surface of the rotor core 20 can be used as a machining position for dynamic balance weight removal to meet the rotor balance requirement. Compared with the plastic gasket arranged at the axial both ends of the rotor core in the traditional process, the molding material used in the utility model, especially the bulk molding compound BMC mainly includes glass fiber and resin and other thermosetting materials, has more stable fluidity, and realizes the axial and radial positioning between the rotor components in the one-piece injection molding process, and at the same time makes the formed mold part 30 have sufficient thickness and strength to support the subsequent dynamic balance adjustment.

[0035] It should be particularly noted that in the above injection molding process, the shaft 10 together with the semi-finished product of the rotor core 20 is prone to shaking due to high-pressure injection in the mold, thereby affecting the formation of the final mold part 30. Therefore, positioning features need to be arranged in the shaft 10 and / or the rotor core 20 to assist in firmly positioning them in the mold for injection molding. On the other hand, in the subsequent magnetization process, in order to ensure the relative positional relationship between the excitation coil and the magnetic steel in the rotor core 20, it is also necessary to ensure the positioning of the non-magnetized rotor in the magnetizer. That is, in the one-piece injection molded rotor of the utility model, positioning features that can be used for injection molding and subsequent rotor magnetization stages need to be designed.

[0036] Therefore, in the further preferred embodiment of the utility model, corresponding positioning feature parts can be arranged on one or both of the shaft 10 and the rotor core 20. For example, as shown in FIG. 6, the shaft 10 is provided with a positioning feature part 40 in the form of a protrusion, and the rotor core 20 is provided with a positioning feature part 50 in the form of a recess. Figure 4As shown, the positioning feature provided on the shaft 10 is in the form of a flat cutout 102 at the end of the shaft 10, while the positioning feature provided on the rotor core 20 is in the form of a positioning hole 204. Either one of the above features or a combination of both can be used to achieve positioning during injection molding and magnetizing without the need to machine any positioning feature on the outer circumference of the rotor core 20, thus not affecting the magnetic circuit inside the rotor core after the rotor is formed and the performance of the brushless motor formed by the subsequent matching with the stator.

[0037] Specifically, as shown in Figure 4 During the process of inserting the rotor 10 through the shaft hole 201 of the rotor core 20 by press fitting, the flat cutout 102 provided at the end of the shaft 10 is made to extend parallel to one of the magnetic steel slots 203, thus ensuring the relative position between the shaft 10 and the rotor core 20. In this way, when the assembled shaft 10 and the semi-finished rotor core 20 are placed into the mold for the injection molding process, the flat cutout can be aligned with the complementary feature in the mold base, thus achieving positioning of the rotor during the injection molding. Next, during the magnetizing stage, the integrally injection molded rotor is placed into the magnetizing machine, at which time the flat cutout at the end of the shaft still serves as the positioning feature and is aligned with the corresponding complementary feature in the magnetizing machine, thus achieving positioning of the rotor in the magnetizing machine so that the magnetic steel inserted into each magnetic steel slot is aligned with the corresponding exciting coil in the magnetizing machine. It can be understood that, in order to maintain balance in rotation, it is preferred that a pair of flat cutouts be provided at the end of the shaft, which are opposite to and parallel to each other. However, the number and arrangement of the flat cutouts can be flexibly set as needed. For example, for a magnetic steel slot in the shape of a straight line, in addition to the square (i.e., a regular quadrilateral) distribution shown in the figure, a regular hexagonal, regular octagonal, etc. distribution can also be provided as needed. Correspondingly, three pairs or four pairs of flat cutouts opposite to and parallel to each other can be machined at the end of the shaft, thus forming a shape of a regular quadrilateral, regular hexagon, regular octagon, etc. in cross section of the end of the shaft viewed in the direction of extension along the rotation axis of the shaft.

[0038] On the other hand, additionally or alternatively, a positioning feature in the form of a positioning hole 204 can be provided in the rotor core 20. As shown in Figure 2a During machining of the rotor core sheet, at least two positioning holes 204 are prefabricated, which are uniformly distributed around the shaft hole 201. And for the magnetic steel slots 203 in the shape of a straight line shown in the figure to be square, each positioning hole 204 is on the perpendicular line from the center of the shaft hole 201 to the corresponding magnetic steel slot 203 (as shown by the dashed line in the figure) when viewed in the cross section perpendicular to the rotation axis of the shaft. In this way, the prefabricated positioning holes 204 can be as close as possible to the center of each magnetic steel slot 203, thus not affecting the magnetic circuit of the rotor during the subsequent magnetizing process (see details inFigure 5 ). It is understood that, in order to maintain the balance in rotation, the positioning holes 204 are preferably arranged in pairs symmetrically about the center of the shaft hole 201. For example, in the case where the magnetic steel slots 203 are arranged in a straight square as shown in the figure, only one pair of positioning holes 204 (such as Figure 2a As shown), the two positioning holes 204 are located on the perpendicular bisector of a pair of magnetic steel slots 203 arranged parallel to each other; two pairs of four positioning holes 204 can also be provided, so that each positioning hole 204 is located on the perpendicular line from the center of the shaft hole 201 to the corresponding magnetic steel slot 203, and the positioning holes 204 are evenly distributed around the shaft hole 201 (as shown). Figure 2b As shown). It is understandable that for the straight-shaped magnetic steel slot, in addition to Figure 2a-2b The distribution is similar to a square, and can also be set to a regular hexagonal deformation, a regular octagonal distribution, etc. as needed. The arrangement of the positioning holes 204 is the same as above, and the number can be set to three pairs, four pairs, etc., wherein the pairs of positioning holes 204 are arranged symmetrically about the center of the shaft hole 201.

[0039] On this basis, a plurality of rotor core sheets are laminated to form the rotor core 20. During the lamination process, the rotor core sheets are laminated by a plurality of riveted portions 205 (e.g., Figure 2b (shown in FIG) are aligned with each other so that the shaft holes and positioning holes machined on each rotor core sheet are aligned with the shaft holes and positioning holes machined on the remaining rotor core sheets. It is understood that positioning holes 204 are formed in the rotor core 20 formed by lamination, extending in a direction parallel to the axial direction of the rotor core 20. When the assembled shaft 10 and rotor core 20 semi-finished product are placed in a mold for the injection molding process (the base portion of which is provided with upwardly protruding positioning pins corresponding to the number of positioning holes 204 and having a cross-sectional shape matching the cross-sectional shape of the positioning holes 204), the positioning holes 204 formed in the rotor core 20 are aligned with the positioning pins of the mold so that the ends of the positioning pins at least partially extend into the positioning holes 204, wherein the extended length is approximately one-tenth of the axial length of the entire rotor core 20. This ensures that the rotor is positioned in the mold and does not shift due to the high injection pressure during the injection molding process. It is understood that during the injection molding process, the space portion occupied by the mold's locating pins will correspondingly form locating holes 304 in the final injection molded molded part 30 (see FIG. Figure 3 As shown), the positioning hole 304 will be aligned with the positioning hole 204 in the rotor core 20.

[0040] The positioning hole 304 formed in the molded part 30 can further function as a positioning feature in the magnetizing stage. For example, in addition to the positioning feature complementary to the shape of the flat cutout at the end of the shaft in the magnetizing machine, additionally or alternatively, the magnetizing machine can also be provided with a positioning pin, for example. Unlike the positioning pin in the mold base for the injection molding process, the positioning pin provided in the magnetizing machine can have a relatively small protruding length, because in the magnetizing stage, the positioning pin only needs to extend partially into the positioning hole 304 formed in the molded part 30, without further extending into the positioning hole 204 of the rotor core 20. It can be understood that the cross-sectional shape of the positioning pin provided in the magnetizing machine corresponds to the cross-sectional shape of the positioning hole 304 formed in the molded part 30, and thus to the cross-sectional shape of the positioning hole 204 of the rotor core 20.

[0041] By adopting the technical solutions described above, the utility model discloses a rotor with IPM embedded structure in a motor, which can be integrally injection molded by, for example, mass molding, to ensure the mechanical strength of the rotor and reduce the magnetic flux leakage of the motor to maintain the basic electrical properties of the rotor, while facilitating dynamic balancing to meet the balancing requirements of the rotor. Further, the utility model discloses a positioning feature provided on the shaft and / or the rotor core and thus a corresponding positioning feature generated in the molded part formed by injection molding, which simultaneously realizes the positioning of the rotor required in the injection molding stage and the magnetizing stage.

[0042] The principles of the utility model are described above in combination with the drawings and preferred embodiments. However, the utility model is not limited to the preferred embodiments described above but can be modified or replaced as follows.

[0043] For example, as shown in Figure 1 , a rib or knurl extending along the axial direction beyond the molded part 30 can be additionally provided on the outer periphery of the shaft 10 to increase the friction between the shaft 10 and the injection molding material, such as BMC material. In this way, the adhesion between the shaft 10 and the injection molding material can be enhanced, thereby facilitating the demolding of the molded part 30 formed by injection molding from the mold and avoiding the risk of the molded part 30 being broken during the demolding process.

[0044] As shown in Figure 2a-2b , for the magnetic steel slots 203 arranged in a linear manner, a magnetic bridge reinforcing rib 302 is provided between two adjacent magnetic steel slots 203, which is formed by the injection molding of the injection molding material, such as BMC material, and can enhance the mechanical strength of the rotor on the one hand, and on the other hand, Figure 5As shown, the presence of the magnetic flux bridge reinforcing ribs 302 can compress the originally large-scale space between the adjacent magnetic steel slots 203, so as to squeeze the magnetic flux into the smaller space around the magnetic flux bridge reinforcing ribs 302 and cause the part of the space to be quickly magnetically saturated, and the magnetic saturation will prevent the further flow of the magnetic flux in the part of the space, so that more magnetic flux will flow between the end portions of the adjacent magnetic steels, thereby enhancing the performance of the entire rotor.

[0045] In addition, in addition to the linear magnetic steel slot 203 arrangement (which can be arranged in a polygonal configuration uniformly around the rotor shaft hole 201 according to the number of magnetic steel slots 203) shown Figure 2a-2b In addition, in addition to the linear magnetic steel slot 203 arrangement (which can be arranged in a polygonal configuration uniformly around the rotor shaft hole 201 according to the number of magnetic steel slots 203) shown Figure 2a-2b As shown, the presence of the magnetic flux bridge reinforcing ribs 302 can compress the originally large-scale space between the adjacent magnetic steel slots 203, so as to squeeze the magnetic flux into the smaller space around the magnetic flux bridge reinforcing ribs 302 and cause the part of the space to be quickly magnetically saturated, and the magnetic saturation will prevent the further flow of the magnetic flux in the part of the space, so that more magnetic flux will flow between the end portions of the adjacent magnetic steels, thereby enhancing the performance of the entire rotor.

[0046] The preferred embodiments of the rotor for a brushless motor are described in detail above with the aid of the drawings. Modifications and supplements to the technology and structure, and recombination of features in the embodiments should all be considered within the scope of the present disclosure without departing from the scope and spirit of the present disclosure as set forth in the following claims. Therefore, these modifications and supplements that can be conceived under the teaching of the present disclosure should be considered as part of the present disclosure. The scope of the present disclosure is limited by the following appended claims, and includes equivalent technologies known at the filing date of the present disclosure and equivalent technologies not yet foreseen.

Claims

1. A rotor for a brushless motor, characterized in that: The rotor comprises a rotating shaft (10) having a rotating axis, a rotor core (20) disposed outside the rotating shaft (10), and a molded part (30) integrally injection-molded around the rotating shaft (10), wherein the rotating shaft (10), the rotor core (20) and the molded part (30) are capable of rotating together around the rotating axis, wherein a plurality of magnetic steel slots (203) for accommodating magnetic steel are provided in the rotor core (20), wherein the plurality of magnetic steel slots (203) together with the magnetic steel accommodated therein surround the rotating shaft (10) and pass through the rotor core (20) along an axial direction parallel to the extension direction of the rotating axis, wherein the molded part (30) covers two end faces of the rotor core (20) in the axial direction, and a positioning feature portion for injection molding and / or magnetization is provided on one end portion of the rotating shaft (10) in the axial direction and / or the rotor core (20).

2. The rotor according to claim 1, characterized in that The rotor core (20) has a shaft hole (201) at its center for receiving the shaft (10), and recessed portions (202) are evenly formed on the peripheral wall of the shaft hole (201) and are recessed toward the rotor core (20) along the radial direction of the shaft (10).

3. The rotor according to claim 2, characterized in that When viewed on a cross section perpendicular to the rotation axis, the plurality of magnetic steel slots (203) are evenly arranged around the rotation shaft hole (201) in a positive polyhedral form, and magnetic bridge reinforcement ribs (302) are provided between adjacent magnetic steel slots (203).

4. The rotor according to claim 3, characterized in that The positioning feature portion provided on the end of the rotating shaft (10) is a flat cutout portion (102). When viewed from the direction in which the rotating axis extends, the flat cutout portion (102) and one of the magnetic steel slots (203) extend in parallel with each other.

5. The rotor according to any one of claims 2 to 4, characterized in that The positioning feature portion provided on the rotor core (20) is at least two positioning holes (204). When viewed on a cross section perpendicular to the rotation axis, each positioning hole (204) is located on a vertical line from the center of the shaft hole (201) to the corresponding magnetic steel slot (203).

6. The rotor according to claim 5, characterized in that The positioning holes (204) are arranged in pairs symmetrically about the center of the rotating shaft hole (201).

7. The rotor according to claim 5, characterized in that The molded part (30) is formed with a positioning hole (304) aligned with the positioning hole (204) provided on the rotor core (20) during the integral injection molding process.

8. The rotor according to claim 2, characterized in that When viewed on a cross section perpendicular to the rotation axis, the multiple magnetic steel slots are evenly arranged around the rotating shaft hole, and each magnetic steel slot is arranged with one end facing the rotating shaft hole and the other end extending radially outward, so that a fan-shaped rotor core segment is defined between every two adjacent magnetic steel slots, and the various rotor core segments are distributed in a ring around the rotating shaft hole.

9. The rotor according to claim 8, characterized in that The positioning feature portion provided on the rotor core is at least two positioning holes, and the positioning holes are provided in pairs in the rotor core block symmetrically distributed about the center of the rotating shaft hole.

10. The rotor according to claim 9, characterized in that When viewed on a cross section perpendicular to the rotation axis, the cross section of the positioning hole gradually narrows from a portion further outward in the radial direction of the rotor core toward a portion closer to the rotating shaft hole in the radial direction.

11. The rotor according to claim 9 or 10, characterized in that The molded part is formed with a positioning hole aligned with the positioning hole provided on the rotor core during the integral injection molding process.

12. The rotor according to any one of claims 1 to 4, characterized in that A rib or knurling extending in the axial direction is provided on the outer periphery of the rotating shaft (10), and the rib or knurling extends beyond the molded part (30) in the axial direction.

13. A brushless motor, characterized in that: Comprising a rotor according to any one of claims 1 to 12.

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