Rotor assembly and motor

Abstract

The utility model discloses a rotor assembly and a motor, and belongs to the technical field of motor equipment. The rotor assembly comprises an injection molding part, an iron core and a plurality of magnetic parts, the iron core extends in the circumferential direction of the rotor assembly, the magnetic parts are distributed in the circumferential direction of the rotor assembly, the iron core is adjacent to the magnetic parts in the radial direction of the rotor assembly, the iron core and the magnetic parts are arranged in the injection molding part, the injection molding part is provided with a positioning hole, and the positioning hole comprises a first part and a second part. In the axial projection of the rotor assembly, the first part is partially overlapped with the iron core and the at least one magnetic piece, and the second part is connected to the first part and arranged between the adjacent magnetic pieces. According to the rotor assembly provided by the embodiment of the utility model, the iron core and the magnetic piece can be simultaneously positioned through the positioning holes in the injection molding piece, the number of the positioning holes is reduced, the design cost and difficulty of a mold are reduced, the risk of cracking caused by stress concentration at the positioning holes can be reduced, and the structural strength of the injection molding piece is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of motor equipment, in particular to a rotor assembly and a motor comprising the rotor assembly. Background Art

[0002] In the related art, the motor is mainly composed of a rotor assembly and a stator assembly, both of which are provided with certain inserts. For components using the injection molding process, the internal inserts need to be positioned during injection molding, that is, positioning holes are provided. However, too many positioning holes will not only increase the cost and difficulty of mold design, but also lead to weak overall structural strength of the component. Utility Model Content

[0003] The utility model aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] Therefore, one object of the present invention is to provide a rotor assembly, which can improve the structural strength and working performance of the rotor assembly.

[0005] Another object of the present invention is to provide a motor, which includes the aforementioned rotor assembly.

[0006] According to the rotor assembly of the embodiment of the utility model, the rotor assembly includes an injection molded part, an iron core and a plurality of magnetic parts, the iron core extends along the circumference of the rotor assembly, the plurality of magnetic parts are distributed along the circumference of the rotor assembly, the iron core is adjacent to the magnetic parts in the radial direction of the rotor assembly, the iron core and the magnetic parts are arranged in the injection molded part, the injection molded part is provided with a positioning hole, the positioning hole includes a first part and a second part, in the axial projection of the rotor assembly, the first part overlaps with the iron core and at least one of the magnetic parts, and the second part is connected to the first part and is arranged between adjacent magnetic parts.

[0007] According to the rotor assembly of the embodiment of the utility model, the iron core and the magnetic parts can be positioned at the same time through the positioning holes on the injection molded parts, thereby reducing the number of positioning holes, reducing the design cost and difficulty of the mold, and being able to reduce the risk of cracking due to stress concentration at the positioning holes, thereby improving the structural strength of the injection molded parts.

[0008] In addition, the rotor assembly according to the above embodiment of the utility model may also have the following additional technical features:

[0009] Optionally, a ratio L1 / R1 of a dimension L1 of the positioning hole along the radial direction of the rotor assembly to a radius dimension R1 of the rotor assembly is not less than 0.01 and not greater than 0.2.

[0010] Optionally, a ratio L2 / L3 of a depth dimension L2 of the positioning hole along the axial direction of the rotor assembly to a dimension L3 of the rotor assembly along the axial direction of the rotor assembly is not less than 0.005 and not greater than 0.8.

[0011] Optionally, the positioning hole includes a first side edge and a second side edge radially opposite to each other along the rotor assembly, the first side edge is farther away from the central axis of the rotor assembly than the second side edge, and the first side edge and the second side edge are set to be arc edges surrounding the central axis, circular arc edges centered on the central axis, or straight edges extending around the central axis.

[0012] Optionally, the positioning hole also includes a third side and a fourth side opposite to each other along the circumference of the rotor assembly, and the first side, the second side, the third side and the fourth side together enclose the positioning hole, and the third side and the fourth side are configured to gradually decrease, gradually increase or remain unchanged in a direction away from the center axis; wherein the first side, the third side, the second side and the fourth side are connected end to end, and the connection between adjacent sides is rounded; or, the third side, the first side and the fourth side are connected in sequence, one end of the second side is separated from the third side by a first opening, and the other end is separated from the fourth side by a second opening.

[0013] Optionally, the second portion gradually expands in a direction approaching the first portion.

[0014] Optionally, a ratio L1 / L4 of a dimension L1 of the positioning hole along the radial direction of the rotor assembly to a dimension L4 of the magnetic component along the radial direction of the rotor assembly is not less than 0.3 and not greater than 0.7.

[0015] Optionally, a ratio L1 / L5 of a dimension L1 of the positioning hole along the radial direction of the rotor assembly to a dimension L5 of the iron core along the radial direction of the rotor assembly is not less than 0.6 and not greater than 1.2.

[0016] Optionally, a ratio L6 / L7 of a dimension L6 of the first portion of the positioning hole along the circumferential direction of the rotor assembly to a dimension L7 of the magnetic component along the circumferential direction of the rotor assembly is not less than 0.3 and not greater than 0.6.

[0017] Optionally, a ratio L6 / L8 of a dimension L6 of the first portion of the positioning hole along the circumferential direction of the rotor assembly to a dimension L8 of the iron core along the circumferential direction of the rotor assembly is not less than 0.02 and not greater than 0.06.

[0018] Optionally, a ratio L9 / L7 of a dimension L9 of the second portion of the positioning hole along the circumferential direction of the rotor assembly to a dimension L7 of the magnetic component along the circumferential direction of the rotor assembly is not less than 0.06 and not greater than 0.09.

[0019] Optionally, a ratio L9 / L8 of a dimension L9 of the second portion of the positioning hole along the circumferential direction of the rotor assembly to a dimension L8 of the iron core along the circumferential direction of the rotor assembly is not less than 0.003 and not greater than 0.007.

[0020] Optionally, a ratio of a dimension L10 of the first portion of the positioning hole along the axial direction of the rotor assembly to a dimension L11 of the magnetic component along the axial direction of the rotor assembly is not less than 0.02 and not more than 0.12.

[0021] Optionally, a ratio of a dimension L10 of the first portion of the positioning hole along the axial direction of the rotor assembly to a dimension L12 of the iron core along the axial direction of the rotor assembly is not less than 0.05 and not more than 0.25.

[0022] Optionally, a ratio of a dimension L13 of the second portion of the positioning hole along the axial direction of the rotor assembly to a dimension L11 of the magnetic component along the axial direction of the rotor assembly is not less than 0.3 and not more than 0.6.

[0023] Optionally, a ratio of a dimension L13 of the second portion of the positioning hole along the axial direction of the rotor assembly to a dimension L12 of the iron core along the axial direction of the rotor assembly is not less than 0.5 and not greater than 1.5.

[0024] Optionally, a ratio of a dimension L6 of the first portion of the positioning hole along the circumferential direction of the rotor assembly to a dimension L14 of a gap between adjacent magnetic components along the circumferential direction of the rotor assembly is not less than 5 and not greater than 10.

[0025] Optionally, a ratio of a dimension L7 of the second portion of the positioning hole along the radial direction of the rotor assembly to a dimension L14 of a gap between adjacent magnetic components along the circumferential direction of the rotor assembly is not less than 0.85 and not greater than 1.2.

[0026] Optionally, the injection molded part has two end surfaces opposite to each other along the axial direction of the rotor assembly, at least one of the two end surfaces of the injection molded part is provided with the positioning hole, and in the axial projection of the rotor assembly, the ratio S1 / S2 of the projection area S1 of the first part of the positioning hole to the corresponding end surface of the injection molded part is not less than 0.006 and not greater than 0.036.

[0027] Optionally, in an axial projection along the rotor assembly, a ratio S3 / S2 of a projection area S3 of the second portion of the locating hole to a corresponding end surface of the injection molded part is not less than 0.0008 and not greater than 0.0028.

[0028] According to the motor of the embodiment of the utility model, the motor includes the rotor assembly mentioned above.

[0029] According to the motor of the embodiment of the utility model, by applying the aforementioned rotor assembly, the working stability of the motor can be improved and the cost of the motor can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the rotor assembly in some embodiments of the present invention.

[0031] Figure 2 yes Figure 1 A partial enlarged view of the embodiment.

[0032] Figure 3 It is a layout diagram of the iron core and multiple magnetic parts in some embodiments of the utility model.

[0033] Figure 4 It is a radial cross-sectional view of a rotor assembly in some embodiments of the present invention.

[0034] Figure 5 It is a schematic diagram of the ejector pin and multiple magnetic parts in some embodiments of the utility model.

[0035] Figure 6 It is a schematic diagram of the rotor assembly in other embodiments of the utility model.

[0036] Figure 7 yes Figure 6 A partial enlarged view of the embodiment.

[0037] Figure 8 It is a schematic diagram of the dimensions of the rotor assembly in some embodiments of the present invention.

[0038] Fig. 9 It is a schematic diagram of the dimensions of the iron core and the magnetic parts in some embodiments of the utility model.

[0039] Fig.10 It is an axial projection diagram of the first part of the positioning hole and the rotor assembly in some embodiments of the utility model.

[0040] Fig.11 It is an axial projection diagram of the second portion of the positioning hole and the rotor assembly in some embodiments of the utility model.

[0041] Reference numerals:

[0042] Rotor assembly 100, injection molded part 10, positioning hole 11, first part 111, second part 112, first side 113, second side 114, third side 115, fourth side 116, first opening 12, second opening 13, iron core 20, magnetic part 30, ejector pin 200, first positioning portion 210, second positioning portion 220, circumferential direction AA. DETAILED DESCRIPTION

[0043] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0044] The utility model provides a rotor assembly 100 and a motor, which can improve the structural strength and working performance of the rotor assembly 100.

[0045] Reference Figures 1 to 11 According to the rotor assembly 100 of the embodiment of the utility model, the rotor assembly 100 includes an injection molded part 10, an iron core 20 and a plurality of magnetic parts 30. The iron core 20 extends along the circumference of the rotor assembly 100. The plurality of magnetic parts 30 are distributed along the circumference of the rotor assembly 100. The iron core 20 is adjacent to the magnetic parts 30 in the radial direction of the rotor assembly 100. The iron core 20 and the magnetic parts 30 are arranged in the injection molded part 10. The injection molded part 10 is provided with a positioning hole 11. The positioning hole 11 includes a first part 111 and a second part 112. In the axial projection of the rotor assembly 100, the first part 111 partially overlaps with the iron core 20 and at least one magnetic part 30. The second part 112 is connected to the first part 111 and is arranged between adjacent magnetic parts 30. In this way, the structural strength and working performance of the rotor assembly 100 can be improved.

[0046] Specifically, a plurality of magnetic parts 30 and an iron core 20 are installed in the injection molded part 10. The magnetic field generated by the plurality of magnetic parts 30 can interact with the magnetic field of the stator assembly so that the rotor assembly 100 rotates relative to the stator assembly to realize the power output of the motor. The iron core 20 can enhance the magnetic field in the rotor assembly 100, thereby improving the working efficiency of the motor. A positioning hole 11 is provided on the injection molded part 10. The positioning hole 11 includes a first part 111 and a second part 112. In the axial projection of the rotor assembly 100, the first part 111 partially overlaps with the iron core 20 and at least one magnetic part 30. It can be understood that the first part 111 of the positioning hole 11 is opposite to the iron core 20 and at least one magnetic part 30. By arranging positioning parts such as a pin 200 in the same positioning hole 11, the positioning of the iron core 20 and at least one magnetic part 30 can be achieved.

[0047] More specifically, when the rotor assembly 100 is injection molded, the iron core 20 and at least one magnetic component 30 can be positioned by the ejector pin 200 on the mold to ensure the installation fit between the iron core 20 and the magnetic component 30 and the injection molded part 10. After the injection molding is completed, a positioning hole 11 will be formed at the positioning position of the ejector pin 200. In this way, compared with the related art in which positioning holes 11 corresponding to the iron core 20 and the magnetic component 30 are respectively arranged on the injection molded part 10, the rotor assembly 100 in the embodiment of the utility model can simultaneously position the iron core 20 and the magnetic component 30 through the positioning holes 11 on the injection molded part 10, thereby reducing the number of positioning holes 11, reducing the design cost and difficulty of the mold, and being able to reduce the risk of cracking caused by stress concentration at the positioning holes 11, thereby improving the structural strength of the injection molded part 10.

[0048] In addition, the positioning hole 11 includes a first part 111 and a second part 112, the second part 112 extends along the axial direction of the rotor assembly 100, and the first part 111 extends vertically along the axial direction of the rotor assembly 100 and is connected to the second part 112; it can be understood that the positioning hole 11 is formed when the ejector 200 is withdrawn after the injection molding of the rotor assembly 100 is completed, and the ejector 200 includes a first positioning portion 210 and a second positioning portion 220, the first positioning portion 210 corresponds to the first part 111, and the second positioning portion 220 corresponds to the second part 112; during injection molding, the first positioning portion 210 can be axially offset from the positioning core 20 and at least one magnetic member 30 to simultaneously position the core 20 and the magnetic member 30; further, the second positioning portion 220 can be provided between adjacent magnetic members 30, thereby positioning two adjacent magnetic members 30 in the circumferential direction of the rotor assembly 100 to further improve the positioning effect.

[0049] In practice, in the axial projection of the rotor assembly 100, the first portion 111 of the positioning hole 11 partially overlaps with the core 20 and the magnetic member 30. However, due to the different axial arrangements of the core 20 and the magnetic member 30, the magnetic member 30 can be positioned through the first portion 111 of the positioning hole 11, and the second portion 112 of the positioning hole 11 can be connected to the position where the first portion 111 and the core 20 overlap axially to position the core 20; of course, the first portion 111 can also position the core 20, and the second portion 112 can also position the magnetic member 30. In addition, in the axial projection of the rotor assembly 100, the first portion 111 of the positioning hole 11 partially overlaps with the core 20 and two adjacent magnetic members 30, so that the two adjacent magnetic members 30 can be axially positioned through the first portion 111 of the positioning hole 11, and the two adjacent magnetic members 30 can be circumferentially positioned through the second portion 112 of the positioning hole 11, and the core 20 portions corresponding to the two adjacent magnetic members 30 can be axially positioned.

[0050] Reference Figure 8In some embodiments of the present invention, the ratio L1 / R1 of the radial dimension L1 of the positioning hole 11 along the rotor assembly 100 to the radius dimension R1 of the rotor assembly 100 is not less than 0.01 and not greater than 0.2; in this way, the positioning effect of the positioning hole 11 on the iron core 20 and the magnetic part 30 can be improved, and the low structural strength of the injection molded part 10 can be avoided.

[0051] Specifically, the positioning hole 11 includes a first portion 111 and a second portion 112. When L1 / R1 is not greater than 0.2, the radial dimension L1 of the positioning hole 11 along the rotor assembly 100 can be the maximum value between the radial dimension of the first portion 111 and the radial dimension of the second portion 112. When L1 / R1 is greater than 0.01, the radial dimension L1 of the positioning hole 11 along the rotor assembly 100 can be the minimum value between the radial dimension of the first portion 111 and the radial dimension of the second portion 112. If the ratio L1 / R1 is less than 0.01, the radial dimension of the positioning hole 11 is too small, and it is not convenient to simultaneously position the iron core 20 and the magnetic part 30 through the positioning hole 11, and the positioning effect is poor. If the ratio L1 / R1 is greater than 0.2, the radial dimension of the positioning hole 11 is too large, resulting in low structural strength of the injection molded part 10 and low working stability. Therefore, the ratio L1 / R1 of the radial dimension L1 of the positioning hole 11 along the rotor assembly 100 to the radius dimension R1 of the rotor assembly 100 can be no less than 0.01 and no more than 0.2; wherein the ratio L1 / R1 can be 0.01, 0.05, 0.1, 0.15, 0.2, etc.

[0052] Reference Fig. 9 In some embodiments of the present invention, the ratio L2 / L3 of the depth dimension L2 of the positioning hole 11 along the axial direction of the rotor assembly 100 to the dimension L3 of the rotor assembly 100 along the axial direction of the rotor assembly 100 is not less than 0.005 and not greater than 0.8; in this way, the positioning effect of the positioning hole 11 on the iron core 20 can be improved, and the low structural strength of the injection molded part 10 can be avoided.

[0053] Specifically, if the ratio L2 / L3 is less than 0.005, the depth dimension of the positioning hole 11 is too small, and the circumferential positioning effect of the two adjacent magnetic parts 30 is weak, resulting in poor installation fit between the magnetic part 30 and the injection molded part 10, affecting the working stability of the motor, and causing the ejector 200 to be unable to well position the core 20 axially; if the ratio L2 / L3 is greater than 0.8, the depth dimension of the positioning hole 11 is too large, and the hollow part inside the injection molded part 10 is large, resulting in a low structural strength of the rotor assembly 100. Therefore, the ratio L2 / L3 of the depth dimension L2 of the positioning hole 11 along the axial direction of the rotor assembly 100 to the dimension L3 of the rotor assembly 100 along the axial direction of the rotor assembly 100 can be not less than 0.005 and not greater than 0.8; wherein, the ratio L2 / L3 can be 0.005, 0.01, 0.05, 0.1, 0.5, 0.8, etc.

[0054] Reference Figure 1 , Figure 2 , Figure 6 and Figure 7 In some embodiments of the utility model, the positioning hole 11 includes a first side 113 and a second side 114 radially opposite to each other along the rotor assembly 100, the first side 113 is farther away from the central axis of the rotor assembly 100 than the second side 114, and the first side 113 and the second side 114 are configured as arc edges surrounding the central axis, circular arc edges centered on the central axis, or straight edges extending around the central axis; in this way, the iron core 20 and the magnetic component 30 can be better positioned through the positioning hole 11.

[0055] Optionally, the iron core 20 and / or the magnetic part 30 are arc-shaped structures or circular arc structures surrounding the central axis of the rotor assembly 100. Therefore, the first side 113 and the second side 114 of the positioning hole 11 can be set as arc-shaped edges surrounding the central axis or circular arc edges centered on the central axis. In this way, the positioning hole 11 can be better aligned with the iron core 20 and the magnetic part 30, making it easier for the ejector pin 200 on the mold to position the iron core 20 and the magnetic part 30, thereby improving the positioning effect of the iron core 20 and the magnetic part 30, thereby improving the installation fit between the injection molded part 10 and the iron core 20 and the magnetic part 30.

[0056] Optionally, the first side 113 and the second side 114 of the positioning hole 11 are set as straight edges extending around the central axis; it can be understood that the first side 113 and the second side 114 of the positioning hole 11 are straight edges extending in the tangent direction of the direction around the central axis of the rotor assembly 100; generally, multiple side edges of the ejector pin 200 of the mold are straight edges, therefore, the side edges of the ejector pin 200 can be structurally adapted to the first side 113 and the second side 114 of the positioning hole 11, so that the ejector pin 200 can position the iron core 20 and the magnetic member 30 through the positioning hole 11, thereby improving the positioning effect.

[0057] Reference Figure 1 and Figure 6 In some embodiments of the utility model, the positioning hole 11 also includes a third side 115 and a fourth side 116 which are opposite to each other along the circumference of the rotor assembly 100, and the first side 113, the second side 114, the third side 115 and the fourth side 116 together form the positioning hole 11, wherein the third side 115 and the fourth side 116 are configured to gradually decrease, gradually increase or remain unchanged in the direction away from the central axis; so as to improve the positioning effect of the iron core 20 and the magnetic component 30.

[0058] Specifically, a plurality of magnetic components 30 are distributed along the circumference of the rotor assembly 100, and the first portion 111 of the positioning hole 11 may be opposite to the two adjacent magnetic components 30 and the portion of the iron core 20 corresponding to the space between the two adjacent magnetic components 30 in the axial direction of the rotor assembly 100, and the second portion 112 of the positioning hole 11 may be provided between the two adjacent magnetic components 30, so that the first portion 111 of the positioning hole 11 may be used for axially positioning the two adjacent magnetic components 30, and the second portion 112 of the positioning hole 11 may be used for axially positioning the iron core 20 corresponding to the space between the two adjacent magnetic components 30, and may be used for circumferentially positioning the two adjacent magnetic components 30; wherein the iron core 20 and the magnetic component 30 are adjacent in the radial direction of the rotor assembly 100, for example, in the radial direction of the rotor assembly 100 and away from the center axis. The upper magnetic component 30 and the iron core 20 are arranged in sequence. At this time, the third side 115 and the fourth side 116 can be set to gradually decrease the distance in the direction away from the central axis, so that the positioning hole 11 corresponds to the iron core 20 and the two adjacent magnetic components 30 to achieve positioning; for another example, the magnetic component 30 and the iron core 20 are arranged in sequence in the radial direction and close to the central axis of the rotor assembly 100. At this time, the third side 115 and the fourth side 116 can be set to gradually increase in the direction away from the central axis, so that the positioning hole 11 corresponds to the iron core 20 and the two adjacent magnetic components 30 to achieve positioning; for another example, the third side 115 and the fourth side 116 of the positioning hole 11 are set to maintain a constant distance in the direction away from the central axis, which can facilitate the molding of the positioning hole 11 and reduce the processing complexity.

[0059] Further, refer to Figure 1 and Figure 2 The first side 113, the third side 115, the second side 114 and the fourth side 116 are connected end to end, and the connection between adjacent sides is rounded; in this way, the connection between the first side 113, the second side 114, the third side 115 and the fourth side 116 can be smoothly transitioned to avoid stress concentration at the connection between the sides, which leads to a reduction in the structural strength of the rotor assembly 100.

[0060] In addition, refer to Figure 6 and Figure 7The third side 115, the first side 113 and the fourth side 116 are connected in sequence, one end of the second side 114 is separated from the third side 115 by a first opening 12, and the other end is separated from the fourth side 116 by a second opening 13. In this way, the reliability of the rotor assembly 100 can be improved; it can be understood that in order to test the reliability of the rotor assembly 100, the rotor assembly 100 can be placed in a temperature cycle change scenario. At this time, since the injection molded part 10 and the insert therein have different sensitivities to temperature, the injection molded part 10 and the insert have different shrinkage degrees, which can easily cause the injection molded part 10 to crack. Therefore, a first opening 12 can be formed between one end of the second side 114 and the third side 115, and a second opening 13 can be formed between the other end of the second side 114 and the fourth side 116, to provide a deformation space for the injection molded part 10, so as to solve the aforementioned cracking problem of the injection molded part 10 and improve the reliability of the rotor assembly 100.

[0061] Reference Figure 4 In some embodiments of the present invention, the second portion 112 gradually expands in a direction close to the first portion 111; specifically, the axial dimension of the iron core 20 is smaller than the axial dimension of the magnetic member 30, and therefore, the axial end surface of the magnetic member 30 can be opposite to the first portion 111 of the positioning hole 11 to axially position the magnetic member 30; and the second portion 112 of the positioning hole 11 can be located between adjacent magnetic members 30 to circumferentially position the magnetic member 30, and the second portion 112 of the positioning hole 11 can be opposite to the axial end surface of the iron core 20 corresponding to the adjacent magnetic members 30 to axially position the iron core 20; wherein the positioning hole 11 is formed by the position where the ejector pin 200 is provided on the magnetic member 30 and the iron core 20, and in order to facilitate the ejector pin 200 to withdraw from the rotor assembly 100 during demolding, the second portion 112 of the positioning hole 11 can be gradually expanded in a direction close to the first portion 111, so as to facilitate the ejector pin 200 to withdraw from the rotor assembly 100.

[0062] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L1 / L4 of the radial dimension L1 of the positioning hole 11 along the rotor assembly 100 to the radial dimension L4 of the magnetic component 30 along the rotor assembly 100 is not less than 0.3 and not greater than 0.7; to ensure a good positioning effect while taking into account the structural strength of the rotor assembly 100.

[0063] Specifically, if the ratio L1 / L4 is less than 0.3, the ratio of the radial dimension L1 of the positioning hole 11 to the radial dimension L4 of the magnetic component 30 is small, and the magnetic component 30 cannot be positioned well; if the ratio L1 / L4 is greater than 0.7, the ratio of the radial dimension L1 of the positioning hole 11 to the radial dimension L4 of the magnetic component 30 is large. At this time, the opening of the positioning hole 11 is prone to cracking and other risks, resulting in a decrease in the structural strength of the rotor assembly 100 and affecting the working stability of the motor; therefore, the ratio L1 / L4 of the radial dimension L1 of the positioning hole 11 to the radial dimension L4 of the magnetic component 30 can be not less than 0.3 and not greater than 0.7; wherein, the ratio L1 / L4 can be 0.3, 0.4, 05, 0.6, 0.7, etc.

[0064] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L1 / L5 of the radial dimension L1 of the positioning hole 11 along the rotor assembly 100 to the radial dimension L5 of the iron core 20 along the rotor assembly 100 is not less than 0.6 and not greater than 1.2; to ensure a good positioning effect while taking into account the structural strength of the rotor assembly 100.

[0065] Specifically, if the ratio L1 / L5 is less than 0.6, the ratio of the radial dimension L1 of the positioning hole 11 to the radial dimension L5 of the iron core 20 is small, and the iron core 20 cannot be positioned well; if the ratio L1 / L5 is greater than 1.2, the ratio of the radial dimension L1 of the positioning hole 11 to the radial dimension L5 of the iron core 20 is large. At this time, the opening of the positioning hole 11 is prone to cracking and other risks, resulting in a decrease in the structural strength of the rotor assembly 100 and affecting the working stability of the motor; therefore, the ratio L1 / L5 of the radial dimension L1 of the positioning hole 11 to the radial dimension L5 of the iron core 20 can be not less than 0.6 and not greater than 1.2; wherein, the ratio L1 / L5 can be 0.6, 0.8, 1, 1.2, etc.

[0066] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L6 / L7 of the dimension L6 of the first part 111 of the positioning hole 11 along the circumference of the rotor assembly 100 to the dimension L7 of the magnetic component 30 along the circumference of the rotor assembly 100 is not less than 0.3 and not greater than 0.6; to ensure a good positioning effect while taking into account the sealing effect during injection molding to avoid material leakage.

[0067] Specifically, if the ratio L6 / L7 is less than 0.3, the ratio of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L7 of the magnetic part 30 is small, and the magnetic part 30 cannot be positioned well; if the ratio L6 / L7 is greater than 0.6, the ratio of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L7 of the magnetic part 30 is large, resulting in poor sealing effect during injection molding and easy material leakage; therefore, the ratio L6 / L7 of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L7 of the magnetic part 30 can be not less than 0.3 and greater than 0.6; wherein, the ratio L6 / L7 can be 0.3, 0.4, 0.5, 0.6, etc.

[0068] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L6 / L8 of the dimension L6 of the first part 111 of the positioning hole 11 along the circumference of the rotor assembly 100 to the dimension L8 of the core 20 along the circumference of the rotor assembly 100 is not less than 0.02 and not greater than 0.06; to ensure a good positioning effect while taking into account the sealing effect during injection molding to avoid material leakage.

[0069] Specifically, if the ratio L6 / L8 is less than 0.02, the ratio of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L8 of the iron core 20 is small, and the iron core 20 cannot be positioned well; if the ratio L6 / L8 is greater than 0.06, the ratio of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L8 of the iron core 20 is large, resulting in poor sealing effect during injection molding and easy material leakage; therefore, the ratio L6 / L8 of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L8 of the iron core 20 can be not less than 0.02 and not greater than 0.06; wherein, the ratio L6 / L8 can be 0.02, 0.03, 0.04, 0.05, 0.06, etc.

[0070] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, a ratio L9 / L7 of a dimension L9 of the second portion 112 of the positioning hole 11 along the circumference of the rotor assembly 100 to a dimension L7 of the magnetic component 30 along the circumference of the rotor assembly 100 is not less than 0.06 and not greater than 0.09; this ensures the structural strength of the ejector pin 200 and facilitates the flow of the melt during injection molding.

[0071] Specifically, the ratio L9 / L7 of the dimension L9 of the second portion 112 of the positioning hole 11 along the circumferential direction of the rotor assembly 100 to the dimension L7 of the magnetic member 30 along the circumferential direction of the rotor assembly 100 can be not less than 0.06 and not more than 0.09; this can ensure that the positioning ejector pin 200 in the mold has a certain strength, improve the service life of the ejector pin 200, and help the flow of the melt during injection molding, and help the wall thickness of the injection molded part 10 to be uniform. Among them, the ratio L9 / L7 can be 0.06, 0.07, 0.08, 0.09, etc.

[0072] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L9 / L8 of the dimension L9 of the second portion 112 of the positioning hole 11 along the circumferential direction of the rotor assembly 100 to the dimension L8 of the core 20 along the circumferential direction of the rotor assembly 100 is not less than 0.003 and not greater than 0.007; this ensures the structural strength of the ejector pin 200 and facilitates the flow of the melt during injection molding.

[0073] Specifically, the ratio L9 / L8 of the dimension L9 of the second portion 112 of the positioning hole 11 along the circumferential direction of the rotor assembly 100 to the dimension L8 of the core 20 along the circumferential direction of the rotor assembly 100 can be not less than 0.003 and not more than 0.007; this can ensure that the positioning ejector pin 200 in the mold has a certain strength, improve the service life of the ejector pin 200, and help the flow of the melt during injection molding, and help the wall thickness of the injection molded part 10 to be uniform. Among them, the ratio L9 / L8 can be 0.003, 0.004, 0.005, 0.006, 0.007, etc.

[0074] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L10 / L11 of the dimension L10 of the first portion 111 of the positioning hole 11 along the axial direction of the rotor assembly 100 to the dimension L11 of the magnetic component 30 along the axial direction of the rotor assembly 100 is not less than 0.02 and not greater than 0.12; in this way, the structural strength of the rotor assembly 100 can be ensured and waste of structural space can be avoided.

[0075] Specifically, the ejector pin 200 can be positioned on the axial end surface of the magnetic component 30 through the first portion 111 of the positioning hole 11, and the ejector pin 200 is connected to the mold. Therefore, during injection molding, the axial dimension of the first portion 111 of the positioning hole 11 is the thickness of the injection molded part 10 between the mold and the axial end surface of the magnetic component 30. If the ratio L10 / L11 is less than 0.02, the ratio of the axial dimension L10 of the first portion 111 of the positioning hole 11 to the axial dimension L11 of the magnetic component 30 is small, the thickness of the injection molded part 10 is thin, and the structure of the rotor assembly 100 is strong. The degree is low; if the ratio L10 / L11 is greater than 0.12, the ratio of the axial dimension L10 of the first portion 111 of the positioning hole 11 to the axial dimension L11 of the magnetic component 30 is large, which wastes the arrangement space in the rotor assembly 100; therefore, the ratio L10 / L11 of the axial dimension L10 of the first portion 111 of the positioning hole 11 to the axial dimension L11 of the magnetic component 30 can be not less than 0.02 and not greater than 0.12; wherein the ratio L10 / L11 can be 0.02, 0.04, 0.08, 0.1, 0.12, etc.

[0076] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L10 / L12 of the dimension L10 of the first portion 111 of the positioning hole 11 along the axial direction of the rotor assembly 100 to the dimension L12 of the core 20 along the axial direction of the rotor assembly 100 is not less than 0.05 and not greater than 0.25; in this way, the structural strength of the rotor assembly 100 can be ensured and waste of structural space can be avoided.

[0077] Specifically, in combination with the above, if the ratio L10 / L12 is less than 0.05, the ratio of the axial dimension L10 of the first part 111 of the positioning hole 11 to the axial dimension L12 of the core 20 is small, the thickness of the injection molded part 10 is thin, and the structural strength of the rotor assembly 100 is low; if the ratio L10 / L12 is greater than 0.25, the ratio of the axial dimension L10 of the first part 111 of the positioning hole 11 to the axial dimension L12 of the core 20 is large, which wastes the arrangement space in the rotor assembly 100; therefore, the ratio L10 / L12 of the dimension L10 of the first part 111 of the positioning hole 11 along the axial direction of the rotor assembly 100 to the dimension L12 of the core 20 along the axial direction of the rotor assembly 100 can be made not less than 0.05 and not greater than 0.25; wherein, the ratio L10 / L12 can be 0.05, 0.01, 0.15, 0.2, 0.25, etc.

[0078] Reference Figure 4 and Fig. 9In some embodiments of the present invention, a ratio L13 / L11 of a dimension L13 of the second portion 112 of the positioning hole 11 along the axial direction of the rotor assembly 100 to a dimension L11 of the magnetic component 30 along the axial direction of the rotor assembly 100 is not less than 0.3 and not greater than 0.6; in this way, a good positioning effect can be ensured and damage to the ejector pin 200 can be avoided.

[0079] Specifically, if the ratio L13 / L11 is less than 0.3, the axial dimension of the second portion 112 of the positioning hole 11 is smaller than the axial dimension of the magnetic component 30, and the magnetic component 30 cannot be well positioned circumferentially through the positioning hole 11; if the ratio L13 / L11 is greater than 0.6, the axial dimension of the second portion 112 of the positioning hole 11 is larger than the axial dimension of the magnetic component 30, and the ejector pin 200 is easily broken and damaged when positioning the magnetic component 30 through the positioning hole 11. Therefore, the ratio L13 / L11 of the dimension L13 of the second portion 112 of the positioning hole 11 along the axial direction of the rotor assembly 100 and the dimension L11 of the magnetic component 30 along the axial direction of the rotor assembly 100 can be not less than 0.3 and not greater than 0.6; wherein, the ratio L13 / L11 can be 0.3, 0.4, 0.5, 0.6, etc.

[0080] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L13 / L12 of the dimension L13 of the second portion 112 of the positioning hole 11 along the axial direction of the rotor assembly 100 to the dimension L12 of the core 20 along the axial direction of the rotor assembly 100 is not less than 0.5 and not greater than 1.5; in this way, a good positioning effect can be ensured and damage to the ejector pin 200 can be avoided.

[0081] Specifically, if the ratio L13 / L12 is less than 0.5, the ratio of the axial dimension of the second portion 112 of the positioning hole 11 to the axial dimension of the core 20 is small, and the core 20 cannot be well axially positioned through the positioning hole 11; if the ratio L13 / L12 is greater than 1.5, the ratio of the axial dimension of the second portion 112 of the positioning hole 11 to the axial dimension of the core 20 is large, and the ejector pin 200 is easily broken and damaged when positioning the core 20 through the positioning hole 11. Therefore, the ratio L13 / L12 of the axial dimension L13 of the second portion 112 of the positioning hole 11 along the rotor assembly 100 to the axial dimension L12 of the core 20 along the rotor assembly 100 can be not less than 0.5 and not greater than 1.5; wherein the ratio L13 / L12 can be 0.5, 0.7, 0.9, 1.2, 1.5, etc.

[0082] Reference Figure 4 and Fig. 9In some embodiments of the present invention, a ratio L6 / L14 of a dimension L6 of the first portion 111 of the positioning hole 11 along the circumferential direction of the rotor assembly 100 to a dimension L14 of a gap between adjacent magnetic components 30 along the circumferential direction of the rotor assembly 100 is not less than 5 and not greater than 10; in this way, the structural strength of the rotor assembly 100 and the positioning effect of the positioning hole 11 can be taken into account.

[0083] Specifically, if the ratio L6 / L14 is less than 5, the ratio of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L14 of the gap between adjacent magnetic parts 30 is small; it is impossible to provide a good positioning effect for the adjacent magnetic parts 30 during positioning; it is understandable that the first part 111 of the positioning hole 11 can axially position the adjacent magnetic parts 30. Since the magnetic parts 30 are provided with chamfers near the gap, the chamfers affect the positioning effect of the ejector pin 200 on the magnetic parts 30, so the ratio L6 / L14 needs to be greater than 5; if the ratio L6 / L14 is greater than 10, the ratio of the circumferential dimension L6 of the first part 111 of the positioning hole 11 to the circumferential dimension L14 of the gap between adjacent magnetic parts 30 is large, which affects the structural strength of the rotor assembly 100, so the ratio L6 / L14 needs to be less than 10; wherein, the ratio L6 / L14 can be 5, 6, 7, 8, 9, 10, etc.

[0084] Reference Figure 4 and Fig. 9 In some embodiments of the present invention, the ratio L7 / L14 of the radial dimension L7 of the second portion 112 of the positioning hole 11 along the rotor assembly 100 and the circumferential dimension L14 of the gap between adjacent magnetic components 30 along the rotor assembly 100 is not less than 0.85 and not greater than 1.2; such a setting can ensure that the wall thickness of the injection molded part 10 is uniform and is conducive to the flow of the melt during injection molding.

[0085] Specifically, the ratio L7 / L14 of the radial dimension L7 of the second portion 112 of the positioning hole 11 and the circumferential dimension L14 of the gap between adjacent magnetic parts 30 can be made not less than 0.85 and not greater than 1.2, thereby ensuring that the wall thickness of the injection molded part 10 between the positioning hole 11 and the magnetic part 30 is uniform, thereby reducing the stress concentration phenomenon of the rotor assembly 100 and facilitating the melt flow during injection molding; wherein the ratio L7 / L14 can be 0.85, 0.9, 1, 1.2, etc.

[0086] Reference Fig.10In some embodiments of the present invention, the injection molded part 10 has two end surfaces along the axial direction of the rotor assembly 100, and at least one of the two end surfaces of the injection molded part 10 is provided with a positioning hole 11; in the axial projection along the rotor assembly 100, the ratio S1 / S2 of the projection area S1 of the first part 111 of the positioning hole 11 on the end surface to the projection area S2 of the corresponding end surface of the injection molded part 10 is not less than 0.006 and not greater than 0.036; in this way, it is possible to avoid the positioning hole 11 being too large in size to reduce the structural strength of the rotor assembly 100, and it is possible to avoid the positioning hole 11 being too small in size to affect the positioning effect of the magnetic part 30 and the iron core 20. Among them, the ratio S1 / S2 can be 0.006, 0.01, 0.02, 0.03, 0.036, etc.

[0087] In addition, refer to Fig.11 In the axial projection of the rotor assembly 100, the ratio S3 / S2 of the projection area S3 of the second portion 112 of the positioning hole 11 on the end surface to the projection area S2 of the corresponding end surface of the injection molded part 10 is not less than 0.0008 and not greater than 0.0028; in this way, it is possible to avoid the positioning hole 11 being too large to reduce the structural strength of the rotor assembly 100, and it is possible to avoid the positioning hole 11 being too small to affect the positioning effect of the magnetic part 30 and the iron core 20. The ratio S3 / S2 can be 0.0008, 0.001, 0.002, 0.0028, etc.

[0088] Reference Figures 1 to 11 According to the motor of the embodiment of the utility model, the motor includes the rotor assembly 100 in the above embodiment. By applying the above rotor assembly 100, the working stability of the motor can be improved and the cost of the motor can be reduced.

[0089] Specifically, the ejector pin 200 of the mold may include a first positioning portion 210 and a second positioning portion 220, wherein the first positioning portion 210 extends vertically in the axial direction, and the second positioning portion 220 is connected to the first positioning portion 210 and extends in the axial direction of the rotor assembly 100; when the rotor assembly 100 is injection molded, the first positioning portion 210 of the ejector pin 200 may be axially opposite to two adjacent magnetic components 30 to axially position the two adjacent magnetic components 30; the second positioning portion 220 of the ejector pin 200 is disposed between the two adjacent magnetic components 30 to circumferentially position the two adjacent magnetic components 30; and the first positioning portion 210 of the ejector pin 200 is opposite to the iron core 20, and the second positioning portion 220 is connected to the portion of the first positioning portion 210 opposite to the iron core 20, so that the second positioning portion 220 of the ejector pin 200 The part 220 can axially position the iron core 20 corresponding to the two adjacent magnetic parts 30; therefore, the positioning hole 11 of the injection molded part 10 will be formed at the positioning position of the ejector pin 200, and the first part 111 of the positioning hole 11 corresponds to the first positioning part 210 of the ejector pin 200, and the second part 112 of the positioning hole 11 corresponds to the second positioning part 220 of the ejector pin 200; in other words, the magnetic part 30 and the iron core 20 can be positioned at the same time through one positioning hole 11. Compared with the related art in which multiple positioning holes 11 corresponding to the magnetic part 30 and the iron core 20 are respectively provided, the embodiment of the utility model can reduce the number of positioning holes 11, reduce the design cost and difficulty of the mold, and at the same time can reduce the risk of cracking caused by stress concentration at the positioning hole 11, thereby improving the structural strength of the injection molded part 10.

[0090] In addition, the ratio L1 / R1 of the radial dimension L1 of the positioning hole 11 to the radius dimension R1 of the rotor assembly 100 is not less than 0.01 and not more than 0.2; in this way, the positioning effect of the iron core 20 and the magnetic member 30 can be improved, and the structural strength of the rotor assembly 100 can be avoided from being reduced. The ratio L2 / L3 of the axial depth dimension L2 of the positioning hole 11 to the axial dimension L3 of the rotor assembly 100 is not less than 0.005 and not more than 0.8; in this way, the positioning effect of the iron core 20 and the magnetic member 30 can be improved, and the structural strength of the rotor assembly 100 can be avoided from being reduced.

[0091] In addition, the positioning hole 11 includes a first side 113, a second side 114, a third side 115 and a fourth side 116, the first side 113 and the second side 114 are opposite to each other in the radial direction, the third side 115 and the fourth side 116 are opposite to each other in the circumferential direction, the first side 113, the third side 115, the second side 114 and the fourth side 116 are connected end to end, and the connection between adjacent sides is rounded, which can reduce the stress concentration generated by the positioning hole 11 and improve the structural strength of the rotor assembly 100; wherein, the first side 113 The first side edge 113 and the second side edge 114 may be an arc edge around the central axis of the rotor assembly 100, and an arc edge centered on the central axis, so as to correspond to the iron core 20 extending along the circumferential direction and the plurality of magnetic parts 30 distributed along the circumferential direction, thereby improving the positioning effect of the iron core 20 and the magnetic parts 30; or, the first side edge 113 and the second side edge 114 may be a straight line edge extending around the central axis of the rotor assembly 100, so as to facilitate the ejector pin 200 with a straight line edge to position the iron core 20 and the magnetic parts 30 through the positioning hole 11, thereby improving the positioning effect.

[0092] Among them, the distance between the third side 115 and the fourth side 116 can be gradually reduced or increased in the direction away from the central axis to adapt to the radial arrangement of the magnetic member 30 and the iron core 20, so as to facilitate the positioning hole 11 to correspond to the magnetic member 30 and the iron core 20 and improve the positioning effect; or, the distance between the third side 115 and the fourth side 116 in the direction away from the central axis remains unchanged, so as to facilitate the molding of the positioning hole 11 and reduce the processing complexity. And the second part 112 of the positioning hole 11 gradually expands in the direction close to the first part 111, so as to facilitate the ejector pin 200 of the mold to exit the rotor assembly 100.

[0093] In addition, balancing mud or balancing nails may be provided in the positioning hole 11 to achieve dynamic balancing correction of the rotor assembly 100 .

[0094] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying 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 the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0095] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0096] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0098] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A rotor assembly, characterized in that: The invention comprises an injection molded part (10), an iron core (20) and a plurality of magnetic parts (30), wherein the iron core (20) extends along the circumference of the rotor assembly, the plurality of magnetic parts (30) are distributed along the circumference of the rotor assembly, the iron core (20) is adjacent to the magnetic parts (30) in the radial direction of the rotor assembly, the iron core (20) and the magnetic parts (30) are arranged in the injection molded part (10), the injection molded part (10) is provided with a positioning hole (11), the positioning hole (11) comprises a first part (111) and a second part (112), in the axial projection of the rotor assembly, the first part (111) partially overlaps with the iron core (20) and at least one of the magnetic parts (30), and the second part (112) is connected to the first part (111) and is arranged between adjacent magnetic parts (30).

2. The rotor assembly according to claim 1, characterized in that A ratio L1 / R1 of a dimension L1 of the positioning hole (11) along the radial direction of the rotor assembly to a radius dimension R1 of the rotor assembly is not less than 0.01 and not greater than 0.

2.

3. The rotor assembly according to claim 1, characterized in that: A ratio L2 / L3 of a depth dimension L2 of the positioning hole (11) along the axial direction of the rotor assembly to an axial dimension L3 of the rotor assembly is not less than 0.005 and not greater than 0.

8.

4. The rotor assembly according to claim 1, characterized in that: The positioning hole (11) comprises a first side edge (113) and a second side edge (114) which are radially opposite to each other along the rotor assembly, wherein the first side edge (113) is farther away from the central axis of the rotor assembly than the second side edge (114), and the first side edge (113) and the second side edge (114) are configured as arc edges surrounding the central axis, circular arc edges centered on the central axis, or straight edges extending around the central axis.

5. The rotor assembly according to claim 4, characterized in that: The positioning hole (11) further comprises a third side edge (115) and a fourth side edge (116) which are opposite to each other along the circumference of the rotor assembly, and the third side edge (115) and the fourth side edge (116) are arranged such that the distances thereof gradually decrease, gradually increase or remain unchanged in a direction away from the central axis; The first side (113), the third side (115), the second side (114) and the fourth side (116) are connected end to end, and the connection between adjacent sides is rounded; or, the third side (115), the first side (113) and the fourth side (116) are connected in sequence, one end of the second side (114) is separated from the third side (115) by a first opening (12), and the other end is separated from the fourth side (116) by a second opening (13).

6. The rotor assembly according to claim 1, characterized in that The second portion (112) gradually expands in a direction approaching the first portion (111).

7. The rotor assembly according to claim 1, characterized in that A ratio L1 / L4 of a dimension L1 of the positioning hole (11) along the radial direction of the rotor assembly to a dimension L4 of the magnetic member (30) along the radial direction of the rotor assembly is not less than 0.3 and not greater than 0.7; Alternatively, a ratio L1 / L5 of a dimension L1 of the positioning hole (11) along the radial direction of the rotor assembly to a dimension L5 of the iron core (20) along the radial direction of the rotor assembly is not less than 0.6 and not greater than 1.

2.

8. The rotor assembly according to claim 1, characterized in that A ratio L6 / L7 of a dimension L6 of the first portion (111) of the positioning hole (11) along the circumferential direction of the rotor assembly to a dimension L7 of the magnetic member (30) along the circumferential direction of the rotor assembly is not less than 0.3 and not greater than 0.6; Or, a ratio L6 / L8 of a dimension L6 of the first portion (111) of the positioning hole (11) along the circumferential direction of the rotor assembly to a dimension L8 of the iron core (20) along the circumferential direction of the rotor assembly is not less than 0.02 and not greater than 0.06; Or, a ratio L9 / L7 of a dimension L9 of the second portion (112) of the positioning hole (11) along the circumferential direction of the rotor assembly to a dimension L7 of the magnetic member (30) along the circumferential direction of the rotor assembly is not less than 0.06 and not greater than 0.09; Alternatively, a ratio L9 / L8 of a dimension L9 of the second portion (112) of the positioning hole (11) along the circumferential direction of the rotor assembly to a dimension L8 of the iron core (20) along the circumferential direction of the rotor assembly is not less than 0.003 and not greater than 0.

007.

9. The rotor assembly according to claim 1, characterized in that: A ratio of a dimension L10 of the first portion (111) of the positioning hole (11) along the axial direction of the rotor assembly to a dimension L11 of the magnetic component (30) along the axial direction of the rotor assembly is not less than 0.02 and not greater than 0.12; Or, a ratio of a dimension L10 of the first portion (111) of the positioning hole (11) along the axial direction of the rotor assembly to a dimension L12 of the iron core (20) along the axial direction of the rotor assembly is not less than 0.05 and not more than 0.25; Or, a ratio of a dimension L13 of the second portion (112) of the positioning hole (11) along the axial direction of the rotor assembly to a dimension L11 of the magnetic component (30) along the axial direction of the rotor assembly is not less than 0.3 and not greater than 0.6; Alternatively, a ratio of a dimension L13 of the second portion (112) of the positioning hole (11) along the axial direction of the rotor assembly to a dimension L12 of the iron core (20) along the axial direction of the rotor assembly is not less than 0.5 and not greater than 1.

5.

10. The rotor assembly according to claim 1, characterized in that The ratio of a dimension L6 of the first portion (111) of the positioning hole (11) along the circumferential direction of the rotor assembly to a dimension L14 of a gap between adjacent magnetic members (30) along the circumferential direction of the rotor assembly is not less than 5 and not more than 10; Alternatively, a ratio of a dimension L7 of the second portion (112) of the positioning hole (11) along the radial direction of the rotor assembly to a dimension L14 of a gap between adjacent magnetic components (30) along the circumferential direction of the rotor assembly is not less than 0.85 and not greater than 1.

2.

11. The rotor assembly according to claim 1, characterized in that The injection molded part (10) has two end surfaces that are opposite to each other along the axial direction of the rotor assembly, at least one of the two end surfaces of the injection molded part (10) is provided with the positioning hole (11), and in the axial projection along the rotor assembly, a ratio S1 / S2 of a projection area S1 of the first portion (111) of the positioning hole (11) to a corresponding end surface of the injection molded part (10) is not less than 0.006 and not greater than 0.

036.

12. The rotor assembly according to claim 11, characterized in that In an axial projection along the rotor assembly, a ratio S3 / S2 of a projection area S3 of the second portion (112) of the positioning hole (11) to a corresponding end surface of the injection molded part (10) is not less than 0.0008 and not greater than 0.0028.

13. A motor, characterized in that: The electric machine comprises the rotor assembly according to any one of claims 1-12.

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