Motor rotor assembly and motor

Abstract

The utility model relates to a motor rotor assembly and a motor in the technical field of motors. The motor rotor assembly comprises a rotor iron core which is provided with a plurality of mounting grooves along the circumferential direction; the motor shaft penetrates through the rotor iron core and is fixed with the rotor iron core; the balance disc is arranged on the motor shaft and is pressed on the end surfaces of the two ends of the rotor iron core along the axial direction; the magnetic steel is mounted in the mounting groove; and the injection molding part is provided with an embedded part and an exposed part which are connected, the embedded part is positioned in the mounting groove and fills a gap between the magnetic steel and the groove wall of the mounting groove, and the exposed part extends out of the mounting groove and is pressed on the end surfaces of the two axial ends of the rotor iron core. The exposed part can replace part of the balance disc, so that the size of the balance disc is reduced, and the raw material cost is reduced; the exposed part is connected with the embedded part which is mounted in the mounting groove and can fix the magnetic steel, so that the structural strength of the exposed part is ensured, the exposed part is not easy to fall off, the balance performance of the motor rotor is ensured, the motor rotor is simple and convenient to assemble, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, and in particular to a motor rotor assembly and a motor. Background Technology

[0002] With the rapid development of new energy vehicles, these vehicles place higher demands on motor speed and operating environment, especially on the balance of the motor rotor when it rotates at high speed. Currently, some methods balance the motor rotor by installing a balance disc, but common balance discs are usually made of aluminum, which are expensive and create significant cost pressures, making the product less competitive in the market. Other methods balance the motor rotor by installing a large cover plate and balance disc, which is not only costly but also very inconvenient to assemble and produce. Utility Model Content

[0003] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a motor rotor assembly and a motor to solve the problems of difficult assembly and high cost of the rotor balancing assembly of the motor in the prior art.

[0004] To achieve the above and other related objectives, this utility model provides a motor rotor assembly, comprising:

[0005] A rotor core, wherein multiple mounting slots are provided along the circumferential direction on the rotor core;

[0006] A motor shaft passes through the rotor core and is fixed to the rotor core;

[0007] A balance disc is mounted on the motor shaft and presses against the end faces of both ends of the rotor core along the axial direction.

[0008] A magnet, wherein the magnet is installed in the mounting groove;

[0009] The injection molded part has a connected inner portion and an exposed portion. The inner portion is located in the mounting groove and fills the gap between the magnet and the groove wall of the mounting groove. The exposed portion extends out of the mounting groove and presses against the end faces of both ends of the rotor core along the axial direction.

[0010] Optionally, the rotor core includes a plurality of silicon steel sheets stacked along the axial direction, each of the silicon steel sheets having a slot and a magnet installed thereon, and the slots of the silicon steel sheets being axially connected to form the mounting groove.

[0011] Optionally, the embedded portion is located within the slot, and the exposed portion extends out of the slot and presses against the end faces of the silicon steel sheets located at both ends along the stacking direction of the plurality of silicon steel sheets.

[0012] Optionally, in the stacking direction of the plurality of silicon steel sheets, the slots on the silicon steel sheets at both ends include a plastic injection channel segment and a mounting segment on which the magnet is mounted. The mounting segment and the plastic injection channel segment are distributed and connected along the length direction of the magnet. The injection molded part includes a thermosetting material filler. A first portion of the injection molded part fills the mounting segment and cures to form the inset portion. A second portion of the injection molded part fills the plastic injection channel segment and extends from the plastic injection channel segment to the end face of the silicon steel sheet and cures to form the exposed portion.

[0013] Optionally, the cross-section of the exposed portion is similar to the cross-section of the injection molding channel section, and the height of the exposed portion extending beyond the end face of the silicon steel sheet is H, where 0.5mm≤H≤2.5mm.

[0014] Optionally, the mounting groove has a proximal end close to the center of the rotor core and a distal end away from the center of the rotor core, with the exposed portion disposed at the distal end of the mounting groove; or, the exposed portion is disposed at both the distal end and the proximal end of the mounting groove.

[0015] Optionally, the exposed portion at the distal end of the mounting slot extends along the end face of the rotor core and is integrally connected with another exposed portion located at the distal end of an adjacent mounting slot.

[0016] Optionally, every two symmetrically arranged mounting slots form a mounting slot pair, and one or more mounting slot pairs distributed radially along the rotor core form a mounting slot group. The number of mounting slot groups is multiple, and the multiple mounting slot groups are evenly distributed along the circumference of the rotor core and located on the outer periphery of the balance disc.

[0017] Optionally, the distance between the proximal ends of the two mounting slots in the same mounting slot pair is less than the distance between the distal ends of the two mounting slots.

[0018] Optionally, every two symmetrically arranged magnets mounted on the same silicon steel sheet form a magnet pair. The magnets have a proximal end close to the center of the rotor core and a distal end far from the center of the rotor core along their length direction. The distance between the proximal ends of the two magnets in the same magnet pair is less than the distance between the distal ends of the two magnets.

[0019] Optionally, one or more pairs of magnets distributed radially along the rotor core form a magnet group, and the number of magnet groups is multiple. The multiple magnet groups are evenly distributed circumferentially along the rotor core, and the magnet groups and the exposed portion are located on the outer periphery of the balance disc.

[0020] Optionally, the contact width between the exposed portion and the end face of the rotor core is W, where 0.2mm ≤ W ≤ 1.5mm.

[0021] To achieve the above and other related objectives, this application also provides an electric motor, including the motor rotor assembly as described above.

[0022] As described above, the motor rotor assembly and motor of this utility model have at least the following beneficial effects: the exposed part cooperates with the balance disc to press down the end faces of both ends of the rotor core. The exposed part can replace part of the balance disc, which is conducive to reducing the size of the balance disc and eliminating the need for additional steel sleeves or cover plates and other parts, thus reducing raw material costs. Based on this, the exposed part is connected to the embedded part installed in the mounting groove and capable of fixing the magnets. On the one hand, this ensures the structural strength of the exposed part and prevents it from falling off, thereby ensuring the balance performance of the motor rotor. On the other hand, it simplifies the structure, makes assembly simple and convenient, and helps to reduce production costs. Attached Figure Description

[0023] Figure 1 The diagram shown is a structural schematic of a first embodiment of the motor rotor assembly of this utility model.

[0024] Figure 2 Displayed as Figure 1 A partial structural diagram of the injection molded part;

[0025] Figure 3 Displayed as Figure 1 A partial structural diagram of the rotor core before the installation of magnets and injection-molded parts;

[0026] Figure 4 Displayed as Figure 1 A partial structural diagram of the rotor core after the installation of magnets and injection-molded parts;

[0027] Figure 5 Displayed as Figure 1 A side view of a partial structure of the rotor assembly of the electric motor;

[0028] Figure 6 Displayed as Figure 1 Top view of the rotor assembly of the electric motor;

[0029] Figure 7 Displayed as Figure 6 Sectional view at point AA;

[0030] Figure 8 Displayed as Figure 1 Bottom view of the rotor assembly of the electric motor;

[0031] Figure 9 Displayed as Figure 8 A magnified schematic diagram of part B in the middle;

[0032] Figure 10 The diagram shows a structural schematic of the magnet in Embodiment 1 of the motor rotor assembly of this utility model.

[0033] Figure 11 The image shown is a partial top view of the magnet assembly located on the same silicon steel sheet in Embodiment 1 of the motor rotor assembly of this utility model.

[0034] Figure 12 This is a partial structural diagram of the rotor core before the installation of magnets and injection molded parts, which is a second embodiment of the motor rotor assembly of this utility model.

[0035] Figure 13 This is a partial structural diagram of the rotor core before the installation of magnets and injection molded parts, which is a third embodiment of the motor rotor assembly of this utility model.

[0036] Figure 14 The diagram shows a partial structural view of the rotor core before the installation of magnets and injection molded parts, as shown in Embodiment 4 of the present invention for the motor rotor assembly.

[0037] Part Number Explanation

[0038] Rotor core 1, mounting slot 11, slot 111, mounting section 112, injection molding channel section 113, silicon steel sheet 12, mounting slot pair 13, mounting slot group 14, motor shaft 2, balance disc 3, magnet group 4, magnet pair 41, magnet 411, injection molded part 5, embedded part 51, exposed part 52, first exposed part 521, second exposed part 522, third exposed part 523, fourth exposed part 524. Detailed Implementation

[0039] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.

[0040] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show components related to this utility model and are not drawn according to the actual number, shape, and size of the components in implementation. In actual implementation, the form, quantity, and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex. The structures, proportions, sizes, etc., shown in the accompanying drawings are only used to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model. Meanwhile, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in this specification are only for clarity of description and are not intended to limit the scope of implementation of this utility model. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered as within the scope of implementation of this utility model.

[0041] See Figures 1 to 5 and Figure 10 In some alternative embodiments, this application provides a motor rotor assembly, which includes a rotor core 1, a motor shaft 2, a balance disc 3, a magnet 411, and an injection molded part 5. The rotor core 1 has multiple mounting slots 11 arranged circumferentially. The motor shaft 2 passes through the rotor core 1 and is fixed to the rotor core 1. The rotor core 1 and the motor shaft 2 can rotate together. The balance disc 3 is installed on the motor shaft 2 and presses on the end faces of the rotor core 1 at both ends along the axial direction to prevent the end faces of the rotor core 1 from tilting up and affecting the balance performance of the rotor core 1. The balance disc 3, the motor shaft 2 and the rotor core 1 can rotate together. The magnet 411 is installed in the mounting slot 11. The injection molded part 5 has a connected inner part 51 and an exposed part 52. The inner part 51 is located in the mounting slot 11 and fills the gap between the magnet 411 and the slot wall of the mounting slot 11 to fix the magnet 411. The exposed part 52 extends out of the mounting slot 11 and presses on the end faces of the rotor core 1 at both ends along the axial direction.

[0042] Optionally, the injection molded part 5 includes a thermosetting material filler, or in other words, the injection molded part 5 is made of a thermosetting material. Further, the thermosetting material includes thermosetting resins such as epoxy resin or unsaturated polyester resin. The injection molded part 5 is integrally injection molded, which not only ensures structural stability and reliability but also facilitates production and assembly, thus helping to reduce production costs.

[0043] Optionally, the inset portion 51 of the injection molded part 5 at least covers a portion of the magnet 411, so that the magnet 411 can be stably installed in the mounting groove 11, the magnet 411 is not easy to shake, and the structure is stable and reliable. Furthermore, the magnet 411 is completely covered by the inset portion 51, that is, the surface of the magnet 411 is covered by the inset portion 51; wherein, the magnet 411 can be cuboid in shape, having an inlet end close to the center of the rotor core 1 and a distal end away from the rotor core 1 along its length direction.

[0044] Optionally, the centerline of the rotor core 1, the centerline of the balance disc 3, and the centerline of the motor shaft 2 coincide.

[0045] Optionally, the balance disc 3 is pressed on the end face of the rotor core 1 near the center of the rotor core 1, and the exposed part 52 is located on the outer periphery of the balance disc 3 so that the exposed part 52 and the balance disc 3 cooperate to press on different positions of the end face of the rotor core 1, thereby reducing the risk of the end face of the rotor core 1 lifting up.

[0046] In the motor rotor assembly of the above embodiment, the exposed part 52 cooperates with the balance disc 3 to press down on different positions of the end face of the rotor core 1 to prevent the end face of the rotor core 1 from tilting up, thereby ensuring the balance of the rotor core 1. The position pressed down by the exposed part 52 does not need to be pressed down by the balance disc 3, which is beneficial to reduce the size of the balance disc 3 and reduce the cost of raw materials. In addition, the exposed part 52 is connected to the embedded part 51 located in the mounting groove 11 as a whole, which ensures the strength of the exposed part 52. Even when the rotor core 1 is running at high speed and is flushed by oil, the exposed part 52 is not easy to fall off the rotor core 1 and can be stably pressed on the end face of the rotor core 1.

[0047] See Figure 1 , Figures 3 to 9 In some optional embodiments, the rotor core 1 includes a plurality of silicon steel sheets 12 stacked along the axial direction of the rotor core 1. Each silicon steel sheet 12 is provided with a slot 111 and a magnet 411 is installed thereon. The slots 111 of each silicon steel sheet 12 are axially connected to form a mounting groove 11. The inset portion 51 of the same injection molded part 5 is distributed in each slot 111 that forms the same mounting groove 11 to fix the magnet 411 installed in each slot 111.

[0048] Optionally, the embedded part 51 is located in the slot 111, and the exposed part 52 extends out of the slot 111 and presses on the end faces of the silicon steel sheets 12 located at both ends along the stacking direction of the plurality of silicon steel sheets 12. The exposed part 52 pressing on the end faces of the silicon steel sheets 12 located at the ends helps to prevent the silicon steel sheets 12 from warping. In particular, it can effectively prevent the silicon steel sheets 12 located at the ends from warping during transfer magnetization and high-speed operation, thus ensuring the balance of the rotor core 1.

[0049] Optionally, in the stacking direction of the plurality of silicon steel sheets 12, the slots 111 on the silicon steel sheets 12 at both ends include a plastic injection channel section 113 and a mounting section 112 on which a magnet 411 is mounted. The mounting section 112 and the plastic injection channel section 113 are distributed and connected along the length direction of the magnet 411. A first part of the injection molded part 5 is filled in the mounting section 112 and cured to form an embedded part 51. A second part of the injection molded part 5 is filled in the plastic injection channel section 113 and extends from the plastic injection channel section 113 to the end face of the silicon steel sheet 12 and cured to form an exposed part 52. In this embodiment, at least one end of the slot 111 of the silicon steel sheet 12 located at the end is provided with a plastic injection channel section 113. Specifically, the slot 111 has a proximal end close to the center of the rotor core 1 and a distal end away from the center of the rotor core 1 along its length direction. In this embodiment, the length direction of the slot 111 can be the same as the length direction of the magnet 411. The plastic injection channel section 113 is provided at one end of the slot 111 away from the center of the rotor core 1, or the plastic injection channel section 113 is provided at both ends of the slot 111. Providing the plastic injection channel section 113 is beneficial for the flow of thermosetting materials during injection molding.

[0050] Optional, see 3 to Figure 5 The cross-section of the exposed portion 52 is similar to that of the injection molding channel section 113, allowing the exposed portion 52 to extend from the injection molding channel section 113 to the outside of the rotor core 1 and to be higher than the end face of the rotor core 1. This helps ensure the feasibility of the injection molding process and the strength of the exposed portion 52. The height of the exposed portion 52 extending beyond the end face of the silicon steel sheet 12 is H, 0.5mm≤H≤2.5mm, which further helps ensure the feasibility of the injection molding process and the strength of the exposed portion 52. Even under the action of oil flushing and high-speed centrifugal force, it can keep pressing down on the end face of the silicon steel sheet 12 and is not prone to failure. The cross-section of the exposed portion 52 is parallel to the end face of the rotor core 1. Furthermore, H can be any value among 0.8mm, 1mm, 1.5mm, or 2.3mm.

[0051] Optional, see Figure 9 The contact width between the exposed portion 52 and the end face of the rotor core 1 is W, where 0.2mm ≤ W ≤ 1.5mm. In other words, the contact width between the exposed portion 52 and the end face of the silicon steel sheet 12 located at the end is W. This helps ensure that the exposed portion 52 is fully pressed against the end face of the silicon steel sheet 12, thereby preventing the silicon steel sheet 12 from warping. Furthermore, W can be any value among 0.3mm, 0.5mm, 1mm, or 1.2mm.

[0052] Optionally, the mounting groove 11 extends through the end faces of both ends of the rotor core 1 along the axial direction of the rotor core 1. That is, the mounting groove 11 extends through multiple silicon steel sheets 12 along the axial direction of the rotor core 1, which facilitates the integral injection molding of the injection molded part 5, simplifies the processing, and allows the embedded parts 51 in each slot 111 of the same mounting groove 11 to be connected as one unit.

[0053] Specifically, during the production and assembly process, the magnet 411 is installed in the mounting section 112 of the corresponding slot 111. Multiple silicon steel sheets 12 are stacked so that the multiple slots 111 corresponding in the axial direction are connected to form the mounting groove 11. Thermosetting material filler is injected through the injection mold nozzle. The thermosetting material filler first reaches the end face of the first end of the rotor core 1, enters the mounting section 112 from the injection channel section 113 on the silicon steel sheet 12 at the first end of the rotor core 1, and flows into the slots 111 of each silicon steel sheet 12 in sequence until it reaches the mounting section 112 on the silicon steel sheet 12 at the second end of the rotor core 1 and flows out from the injection channel section 113 to the end face of the second end of the rotor core 1. After the thermosetting material filler is cured, it forms the embedded part 51 and the exposed part 52 at the corresponding position. The rotor core 1 with this structure design is simple and convenient to process, produce and assemble, which helps to reduce costs in terms of materials and production processes.

[0054] The motor rotor assembly of the above embodiment has a simple and low-cost injection molding process for the injection molded part 5. The injection molded part 5 is integrally molded, which ensures the reliability of the injection molded part 5 in a high-speed oil-cooled environment, thereby effectively preventing the end face of the rotor core 1 from warping and ensuring the balance of the rotor core 1.

[0055] See Figures 1 to 4 , Figure 10 and Figure 11 In some alternative embodiments, the mounting groove 11 has a proximal end near the center of the rotor core 1 and a distal end away from the center of the rotor core 1 along its length direction. The length direction of the mounting groove 11 may be the same as the length direction of the slot 111, and the exposed portion 52 is provided at the distal end of the mounting groove 11; or, the exposed portion 52 is provided at both the distal end and the proximal end of the mounting groove 11. The exposed portion 52 corresponds to the injection molding channel section 113.

[0056] Optionally, the exposed portion 52 located at the distal end of the mounting slot 11 extends along the end face of the rotor core 1 and is integrally connected with another exposed portion 52 located at the distal end of an adjacent mounting slot 11. For details, see [link to relevant documentation]. Figure 2 and Figure 4The multiple exposed portions 52 disposed at the distal ends of the multiple mounting slots 11 are respectively a first exposed portion 521, a second exposed portion 522, and a third exposed portion 523. The adjacent first exposed portion 521 and the second exposed portion 522 are connected as one unit or disconnected, and the adjacent second exposed portion 522 and the third exposed portion 523 are connected as one unit or disconnected. In other words, only two adjacent portions of the first exposed portion 521, the second exposed portion 522, and the third exposed portion 523 are connected, all three adjacent portions are connected, or all three are disconnected. It can be understood that the multiple exposed portions 52 are not limited to the number and connection method listed above, and can be flexibly set according to the needs or the number and distribution of the mounting slots 11. When two or all three of the first exposed portion 521, second exposed portion 522, and third exposed portion 523 are connected, the layout is compact. The connected exposed portions 52 can share a gate, for example, the first exposed portion 521 and the second exposed portion 522 can share a gate, which helps to save on the gate of the injection mold, increase the life of the injection mold, and reduce costs. The risk of warping of the silicon steel sheet 12 near the center of the rotor core 1 is lower than that of the position far from the center of the rotor core 1. The multiple exposed portions 52 provided at the proximal ends of the multiple mounting slots 11 are designated as fourth exposed portions 524. The fourth exposed portions 524 can be reduced or eliminated as needed, providing flexibility to effectively prevent warping of the silicon steel sheet 12 while reducing costs.

[0057] Optionally, every two symmetrically arranged magnets 411 mounted on the same silicon steel sheet 12 form a magnet pair 41. The magnets 411 have a proximal end close to the center of the rotor core 1 and a distal end far from the center of the rotor core 1 along their length direction. The proximal end of the magnet 411 corresponds to the proximal end of the mounting groove 11, and the distal end of the magnet 411 corresponds to the distal end of the mounting groove 11. The distance D1 between the proximal ends of the two magnets 411 in the same magnet pair 41 is smaller than the distance D2 between the distal ends of the two magnets 411. Specifically, the two magnets 411 in the same magnet pair 41 can be arranged in a figure-eight shape. Furthermore, one or more pairs of magnets 41 distributed radially along the rotor core 1 form a magnet group 4. That is, each magnet group 4 may include one or more pairs of magnets 41. There are multiple magnet groups 4. The multiple magnet groups 4 are evenly distributed along the circumference of the rotor core 1, with a symmetrical structure. Both the magnet groups 4 and the exposed part 52 are located on the outer periphery of the balance disk 3, which is beneficial to improving the balance of the rotor core 1.

[0058] In the motor rotor assembly of the above embodiment, at least the distal end of the mounting slot 11 is provided with an exposed portion 52, which has a stable structure and ensures that the silicon steel sheet 12 at the end of the rotor core 1 is not prone to warping, thereby ensuring the balance of the motor rotor assembly.

[0059] See Figure 1 , Figure 3, Figures 11 to 14 In some optional embodiments, every two symmetrically arranged mounting slots 11 form a mounting slot pair 13. One or more mounting slot pairs 13 distributed radially along the rotor core 1 form a mounting slot group 14. That is, each mounting slot group 14 includes one or more mounting slot pairs 13. When multiple mounting slot pairs 13 are included, they are distributed radially along the rotor core 1. There are multiple mounting slot groups 14, which are evenly distributed circumferentially along the rotor core 1 and located on the outer periphery of the balance disc 3. The number of mounting slot pairs 13 included in each mounting slot group 14 can be set according to requirements. The distribution positions of the two magnets 411 of each magnet pair 41 correspond to the distribution positions of the two mounting slots 11 of each mounting slot pair 13.

[0060] Optionally, the distance D3 between the proximal ends of the two mounting slots 11 in the same mounting slot pair 13 is smaller than the distance D4 between the distal ends of the two mounting slots 11. For example, the two mounting slots 11 in the same mounting slot pair 13 can be in a figure-eight shape. Furthermore, the cross-sections of the two mounting slots 11 in the same mounting slot pair 13 are identical, which helps improve balance. It is understood that the cross-section of the mounting section 112 of the mounting slot 11 can be square, fan-shaped, or other shapes, and the specific shape can be flexibly set according to requirements; the shape of the cross-section of the injection molding channel section 113 can be flexibly set according to requirements. The cross-section of the injection molding channel section 113 at the proximal end of the same mounting slot 11 can be the same or different from the cross-section of the injection molding channel section 113 at the distal end, and the cross-sections of the injection molding channel sections 113 of the mounting slots 11 in different mounting slot pairs 13 can be the same or different.

[0061] Optional, see Figure 12 Each mounting slot group includes one mounting slot pair 13, and correspondingly, each magnet group includes one magnet pair.

[0062] Optional, see Figure 13 Each mounting slot group 14 includes two mounting slot pairs 13, and correspondingly, each magnet group includes two magnet pairs.

[0063] Optional, see Figure 3 , Figure 11 and Figure 14 Each mounting slot group includes 3 mounting slot pairs 13, and each magnet group 4 includes 3 magnet pairs 41.

[0064] In the motor rotor assembly of the above embodiment, the mounting slots 11 are symmetrically arranged on the rotor core 1. The structure is symmetrical and the arrangement is flexible. The number of slots can be flexibly adjusted according to the needs, and the overall balance of the motor rotor assembly structure can be improved.

[0065] See Figures 1 to 11In some alternative embodiments, this application also provides an electric motor, including a motor rotor assembly as described in any of the above embodiments. In addition to the motor rotor assembly, the motor also includes a stator.

[0066] The motor rotor assembly and motor of this utility model, by setting an exposed part 52 to press on the end face of the rotor core 1, helps to reduce costs and prevent the end face of the rotor core 1 from warping. Moreover, the exposed part 52 is connected to the embedded part 51 that can fix the magnet 411 as a whole, which not only improves the structural strength of the exposed part 52, but also facilitates integral injection molding, simplifies the production and assembly process, and reduces costs.

[0067] In the description of this specification, the references to terms such as "this embodiment," "example," and "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0068] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An electric machine rotor assembly, characterized by, The application relates to a rotor core of a motor. The rotor core comprises a plurality of mounting slots arranged circumferentially on the rotor core. The motor shaft passes through the rotor core and is fixed with the rotor core. The balance disc is mounted on the motor shaft and is pressed against the end faces of the rotor core in the axial direction. The magnetic steel is mounted in the mounting slot. The injection-molded part has an embedded portion and an exposed portion, the embedded portion is located in the mounting slot and fills the gap between the magnetic steel and the slot wall of the mounting slot, and the exposed portion extends out of the mounting slot and is pressed against the end faces of the rotor core in the axial direction.

2. The electric machine rotor assembly of claim 1, wherein, The rotor core comprises a plurality of silicon steel sheets arranged in the axial direction, each of the silicon steel sheets is provided with a slot and mounted with the magnetic steel, and the slots of the silicon steel sheets are axially communicated to form the mounting slot.

3. The electric machine rotor assembly of claim 2, wherein, The embedded portion is located in the slot, and the exposed portion extends out of the slot and is pressed against the end faces of the silicon steel sheets located at the two ends in the stacking direction of the silicon steel sheets.

4. The electric machine rotor assembly of claim 2, wherein, In the stacking direction of the silicon steel sheets, the slots on the silicon steel sheets located at the two ends comprise an injection-molding channel segment and a mounting segment mounted with the magnetic steel, the mounting segment and the injection-molding channel segment are distributed and communicated along the length direction of the magnetic steel, the injection-molded part comprises a thermosetting material filling body, a first part of the injection-molded part is filled in the mounting segment and solidified to form the embedded portion, and a second part of the injection-molded part is filled in the injection-molding channel segment and extends from the injection-molding channel segment to the end face of the silicon steel sheet and is solidified to form the exposed portion.

5. The electric machine rotor assembly of claim 4, wherein, The cross section of the exposed portion is similar to the cross section of the injection-molding channel segment, and the height of the exposed portion extending out of the end face of the silicon steel sheet is H, 0.5mm<=H<=2.5mm.

6. The electric machine rotor assembly of claim 1, wherein, The mounting slot has a proximal end close to the center of the rotor core and a distal end away from the center of the rotor core, the exposed portion is arranged at the distal end of the mounting slot, or the exposed portion is arranged at the distal end of the mounting slot and the proximal end of the mounting slot.

7. The electric machine rotor assembly of claim 6, wherein, The exposed portion arranged at the distal end of the mounting slot extends along the end face of the rotor core and is connected with another exposed portion arranged at the distal end of the adjacent mounting slot.

8. The electric machine rotor assembly of claim 6, wherein, Each two symmetrically arranged mounting slots form a mounting slot pair, one mounting slot pair or a plurality of mounting slot pairs distributed in the radial direction of the rotor core form a mounting slot group, the number of the mounting slot groups is a plurality, and the plurality of mounting slot groups are uniformly distributed in the circumferential direction of the rotor core and are located at the outer periphery of the balance disc.

9. The electric machine rotor assembly of claim 8, wherein, The distance between the proximal ends of the two mounting slots of the same mounting slot pair is smaller than the distance between the distal ends of the two mounting slots.

10. The electric motor rotor assembly of claim 2, wherein, Each two symmetrically arranged magnetic steels mounted on the same silicon steel sheet form a magnetic steel pair, the magnetic steel has a proximal end close to the center of the rotor core and a distal end away from the center of the rotor core along the length direction of the magnetic steel, and the distance between the proximal ends of the two magnetic steels of the same magnetic steel pair is smaller than the distance between the distal ends of the two magnetic steels.

11. The electric machine rotor assembly of claim 10, wherein, One of the magnetic steel pairs or a plurality of the magnetic steel pairs distributed along the radial direction of the rotor core is formed as a magnetic steel group, the number of the magnetic steel groups is a plurality, a plurality of the magnetic steel groups are uniformly distributed along the circumferential direction of the rotor core, and the magnetic steel group and the exposed part are located at the outer periphery of the balance disc.

12. The electric machine rotor assembly of claim 1, wherein, The contact width of the exposed part with the end surface of the rotor core is W, and 0.2 mm≤W≤1.5 mm.

13. An electric machine characterized by An electric machine rotor assembly comprising a rotor core according to any one of claims 1 to 12.

Images