Rotor assembly, permanent magnet motor and vehicle
By designing cooling channels and guide grooves in the rotor assembly, direct cooling of the permanent magnet is achieved, solving the problem of low cooling efficiency of permanent magnet motors, improving the cooling effect and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- UNITED AUTOMOTIVE ELECTRONICS SYST
- Filing Date
- 2025-04-22
- Publication Date
- 2026-05-05
AI Technical Summary
The rotor cooling efficiency of existing permanent magnet motors is low, and the cooling medium cools the permanent magnets indirectly, resulting in insufficient cooling efficiency.
Cooling channels, radial guide grooves, axial guide grooves, and flow gaps are set in the rotor assembly. The cooling medium directly immerses the permanent magnet, forming a direct cooling path. The uniform flow of the cooling medium is achieved through the design optimization of the rotor core assembly.
This improves the cooling effect of permanent magnets, reduces production process steps and costs, and simultaneously enhances the mechanical strength and efficiency of permanent magnet motors.
Smart Images
Figure CN224204842U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of permanent magnet motor technology, and in particular relates to a rotor assembly, a permanent magnet motor and a vehicle. Background Technology
[0002] Currently, in order to achieve cooling of permanent magnet motors, a first cooling channel is usually set inside the rotor shaft and a second cooling channel is set inside the rotor core. The first and second cooling channels are connected to achieve cooling of the rotor core, which in turn indirectly cools the permanent magnets on the rotor core that are separated from the second cooling channel. This results in low cooling efficiency. 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 rotor assembly, a permanent magnet motor, and a vehicle to solve the above problems.
[0004] To achieve the above and other related objectives, this utility model provides a rotor assembly, comprising:
[0005] A rotating shaft, wherein a cooling channel is provided inside the rotating shaft;
[0006] The rotor core assembly includes at least a stack of first laminations and a stack of second laminations. The first laminations and the second laminations are overlapped and fitted onto the rotating shaft. The first laminations have at least one layer of magnetic steel grooves corresponding to each magnetic pole. A permanent magnet is disposed in each of the magnetic steel grooves. A flow gap for cooling medium to flow is provided between the permanent magnet and the side wall of the magnetic steel groove. The second laminations have axial flow guide grooves and radial flow guide grooves corresponding to each magnetic pole. The radial flow guide grooves connect the cooling channel and the axial flow guide grooves. The axial flow guide grooves connect to each layer of magnetic steel grooves corresponding to the magnetic pole.
[0007] Optionally, the rotor assembly further includes:
[0008] A balance disc is disposed on the outer side of both ends of the rotor core assembly along the axial direction. The balance disc is sleeved on the rotating shaft and presses and limits the rotor core assembly. The balance disc is provided with an outlet that communicates with the magnet slot.
[0009] Optionally, in each layer of magnetic steel grooves corresponding to the same magnetic pole, the outermost radius of at least one layer of magnetic steel groove is greater than the outermost radius of the axial flow guide groove, so that the magnetic steel groove and the axial flow guide groove form a stepped flow path.
[0010] Optionally, in each layer of magnetic steel grooves corresponding to the same magnetic pole, the outermost layer of magnetic steel groove at least partially overlaps with the axial flow guide groove on the radial width of the first lamination to form a stepped flow channel.
[0011] Optionally, the axial guide channel includes a long arc side and a short arc side arranged sequentially in the circumferential direction, the long arc side and the short arc side are connected by an arc segment, and the middle part of the long arc side is connected to the radial guide channel.
[0012] Optionally, the radial guide groove contains a straight flow channel, and the axial guide groove is arranged in a mirror-symmetric manner with the axis of the straight flow channel as the axis of symmetry.
[0013] Optionally, the first lamination is distributed on both sides of the second lamination and is arranged in a mirror-symmetrical manner with the second lamination as the axis of symmetry;
[0014] or
[0015] The second laminations are distributed on both sides of the first lamination and are arranged in a mirror-symmetrical manner with the first lamination as the axis of symmetry.
[0016] Optionally, multiple first laminations overlap to form a first lamination group, one end of the first lamination group along the axial direction overlaps with the second lamination, and the other end of the first lamination group along the axial direction is pressed and limited by the balance disc.
[0017] Optionally, multiple independent permanent magnets are respectively installed in the magnetic steel groove.
[0018] To achieve the above and other related objectives, this utility model provides a permanent magnet motor, including a stator assembly and the aforementioned rotor assembly.
[0019] To achieve the above-mentioned objectives and other related objectives, this utility model provides a vehicle including the aforementioned permanent magnet motor.
[0020] As described above, the rotor assembly, permanent magnet motor, and vehicle of this invention have the following beneficial effects:
[0021] In this design, the cooling channels, radial guide grooves, axial guide grooves, flow gaps, and outlets form the cooling path for the permanent magnet motor. The cooling medium flows through the cooling channels on the shaft to the radial guide grooves on the second lamination, then through the radial guide grooves to the axial guide grooves, and from there to the flow gap between the magnet slot and the permanent magnet, finally exiting from the outlet of the balance disc. During the cooling process, the permanent magnet is immersed in the cooling path, directly cooled by the cooling medium. Compared to traditional indirect cooling methods, this significantly improves the cooling effect. Because the cooling medium flows into the magnet slot, the radial positioning of the permanent magnet is achieved through the dimensional tolerance between the permanent magnet and the magnet slot, while the axial positioning is achieved through the balance disc. No dispensing or injection molding processes are required to fix the permanent magnet. Attached Figure Description
[0022] Figure 1This is a cross-sectional schematic diagram of the rotor assembly in an embodiment of the present invention.
[0023] Figure 2 This is a front view of the first lamination in an embodiment of this utility model.
[0024] Figure 3 This is a front view of the second lamination in an embodiment of this utility model. Detailed Implementation
[0025] The reference numerals in the accompanying drawings include:
[0026] Shaft 1, Cooling Channel 101
[0027] First stamping 2, magnet slot 201, first magnet slot 2011, second magnet slot 2012, third magnet slot 2013, center line 202.
[0028] Second lamination 3, radial guide groove 301, axial guide groove 302, long arc edge 3021, short arc edge 3022, arc segment 3023.
[0029] Balance disc 4.
[0030] The following specific embodiments 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.
[0031] Reference Appendix Figures 1-3 As shown, in an exemplary embodiment of this application, a rotor assembly is provided, including:
[0032] Rotating shaft 1, with cooling channels 101 inside.
[0033] The rotor core assembly includes at least a stack of first laminations 2 and a stack of second laminations 3. The first laminations 2 and the second laminations 3 are overlapped and sleeved on the rotating shaft 1. The first laminations 2 have at least one layer of magnetic steel grooves 201 corresponding to each magnetic pole. Permanent magnets are respectively arranged in the magnetic steel grooves 201. A flow gap for cooling medium to flow is provided between the permanent magnets and the side wall of the magnetic steel grooves 201. The second laminations 3 have axial flow guide grooves 302 and radial flow guide grooves 301 corresponding to each magnetic pole. The radial flow guide grooves 301 connect the cooling channel 101 and the axial flow guide grooves 302. The axial flow guide grooves 302 are connected to each layer of magnetic steel grooves 201 of the corresponding magnetic pole.
[0034] The balance disc 4 is located on the outer side of both ends of the rotor core assembly along the axial direction. The balance disc 4 is sleeved on the rotating shaft 1 and presses and limits the rotor core assembly. The balance disc 4 is provided with an outlet that communicates with the magnet groove 201.
[0035] For example, the inlet of the cooling channel 101 is located at one end of the rotating shaft 1, and the outlet of the cooling channel 101 is provided on the rotating shaft 1. The outlet of the cooling channel 101 is located at the position where it connects to the radial guide groove 301.
[0036] In this embodiment, the cooling channel 101, radial guide groove 301, axial guide groove 302, flow gap, and outlet form the cooling flow path of the permanent magnet motor. The cooling medium flows through the cooling channel 101 on the rotating shaft 1 to the radial guide groove 301 on the second lamination 3, then flows through the radial guide groove 301 to the axial guide groove 302, and from the axial guide groove 302 to the flow gap between the magnet groove 201 and the permanent magnet, and then flows out from the outlet of the balance disk 4. During the cooling process, the permanent magnet is immersed in the cooling flow path and is directly cooled by the cooling medium. Compared with the traditional indirect cooling of the permanent magnet by the cooling medium, this can effectively improve the cooling effect. Since the cooling medium is introduced into the magnet groove 201, the radial limit of the permanent magnet is achieved by the dimensional tolerance between the permanent magnet and the magnet groove 201, and the axial limit of the permanent magnet is achieved by the balance disk 4. No glue or injection molding process is required to fix the permanent magnet.
[0037] For example, for each magnetic pole, one layer, two layers, three layers, or more layers of magnetic steel grooves 201 can be provided as needed. Compared with two layers of magnetic steel grooves 201, providing three layers of magnetic steel grooves 201 can effectively increase the cooling area of the permanent magnet.
[0038] For example, from the circumference of the first lamination 2 to the center, three layers of arc-shaped magnetic grooves 201 are sequentially arranged for each magnetic pole, which are respectively called the first magnetic groove 2011, the second magnetic groove 2012 and the third magnetic groove 2013, and the curvature of the first magnetic groove 2011, the second magnetic groove 2012 and the third magnetic groove 2013 increases sequentially.
[0039] In an exemplary embodiment, in the same magnetic pole, among the layers of magnetic steel grooves 201 corresponding to the same magnetic pole, the outermost radius of at least one layer of magnetic steel groove 201 is greater than the outermost radius of the axial flow guide groove 302, so that the magnetic steel groove 201 and the axial flow guide groove 302 form a stepped flow path.
[0040] For example, the cooling medium is cooling oil.
[0041] In this embodiment, the stepped flow path is designed to create an axial pressure difference and reduce the flow resistance between the axial flow guide groove 302 and the magnetic groove 201.
[0042] For example, the outermost radius of the first magnetic groove 2011 is denoted as R11, the outermost radius of the second magnetic groove 2012 is denoted as R12, and the outermost radius of the third magnetic groove 2013 is denoted as R13. The outermost radius of the axial guide groove 302 is denoted as R21, where R21≤R11, R21≤R12, R21≤R13, and R11+R12+R13≤3*R21.
[0043] In an exemplary embodiment, among the magnetic steel grooves 201 corresponding to the same magnetic pole, the outermost magnetic steel groove 201 at least partially overlaps with the axial flow channel 302 on the radial width of the first lamination 2 to form a stepped flow channel.
[0044] For example, the minimum distance between the outer side of the first magnetic groove 2011 and the center of the second lamination 3 is denoted as L13, the minimum distance between the axial flow guide groove 302 and the center of the second lamination 3 is denoted as L22, and the width of the axial flow guide groove 302 in the radial direction of the second lamination 3 is denoted as L21, where L13 ≥ L22 + L21. When L13 > L22 + L21, a stepped flow path is formed.
[0045] In an exemplary embodiment, the axial guide channel 302 includes a long arc edge 3021 and a short arc edge 3022 arranged sequentially in the circumferential direction. The long arc edge 3021 and the short arc edge 3022 are connected by an arc segment 3023, and the middle part of the long arc edge 3021 is connected to the radial guide channel 301.
[0046] In this embodiment, the arrangement of the long arc edge 3021, the short arc edge 3022 and the arc segment 3023 makes the axial guide groove 302 form a structure that is recessed towards the center of the second punch 3, which is beneficial to improve the cooling effect and improve the mechanical strength.
[0047] For example, the axial guide channel 302 is fan-shaped.
[0048] For example, the minimum distance between the center of the third magnet groove 2013 and the center of the second lamination 3 is denoted as L11, the width of the third magnet groove 2013 is denoted as L12, and the maximum included angle between the third magnet groove 2013 and the centerline 202 is denoted as a11. The maximum included angle between the axes of the axial guide groove 302 and the radial guide groove 301 is denoted as a21, where L11+L12≥L22, a11≤a21≤(90-(360 / 2p) / 2), where P is the number of pole pairs of the permanent magnet motor.
[0049] In an exemplary embodiment, the radial guide groove 301 contains a straight flow channel, and the axial guide groove 302 is arranged in a mirror-symmetric manner with the axis of the straight flow channel as the first axis of symmetry.
[0050] In this embodiment, the axial flow channel 302 is adapted to the shape of the magnet channel 201. The axial flow channel 302 is mirror-symmetrically arranged with the axis of the straight flow channel as the first axis of symmetry, so that the cooling medium can flow more evenly into the magnet channel 201 and increase the cooling effect.
[0051] In an exemplary embodiment, the first lamination 2 is distributed on both sides of the second lamination 3 and is arranged in a mirror-symmetrical manner with the second lamination 3 as the axis of symmetry;
[0052] or
[0053] The second lamination 3 is distributed on both sides of the first lamination 2 and is arranged in a mirror-symmetrical manner with the first lamination 2 as the axis of symmetry.
[0054] In this embodiment, the first lamination 2 is distributed on both sides of the second lamination 3 and is arranged in a mirror symmetrical manner with the second lamination 3 as the second axis of symmetry, so that the second lamination 3 is located in the middle position of the rotor core assembly. In this way, the cooling medium enters from the middle of the rotor core assembly, which can increase the cooling uniformity of the rotor core assembly.
[0055] It should also be noted that if the second lamination 3 is distributed on both sides of the first lamination 2, compared with the first lamination 2 being distributed on both sides of the second lamination 3, the cooling flow path of the cooling medium will change, resulting in different cooling effects.
[0056] In an exemplary embodiment, multiple first laminations 2 are overlapped to form a first lamination 2 group. One end of the first lamination 2 group along the axial direction overlaps with a second lamination 3, and the other end of the first lamination 2 group along the axial direction is pressed and limited by a balance disc 4.
[0057] In this embodiment, along the same direction of the axis of the rotating shaft 1, one balance disc 4, the first punch 2, the second punch 3 and another balance disc 4 are arranged in a sequentially overlapping manner, or one balance disc 4, the second punch 3, the first punch 2 and another balance disc 4 are arranged in a sequentially overlapping manner.
[0058] In one exemplary embodiment, multiple independent permanent magnets are respectively disposed in the magnetic steel groove 201.
[0059] It should be noted that traditional permanent magnet motors use permanent magnets of different specifications, which necessitates the production line to prepare different tooling fixtures and material control measures for each type of permanent magnet. In this embodiment, the permanent magnets are manufactured in segmented form, with each segment having the same shape and size. Compared to traditional permanent magnet motors using permanent magnets of different sizes, this eliminates the need for tooling fixtures for different sizes of permanent magnets on the production line, as well as different material control measures. There are no special fixing connections between each permanent magnet segment, reducing process steps and production costs. Using segmented permanent magnets for each pole reduces permanent magnet motor losses, improves motor efficiency, and increases the contact area between the permanent magnet and the cooling medium.
[0060] In one exemplary embodiment of this application, a permanent magnet motor is provided, including a stator assembly and the aforementioned rotor assembly.
[0061] In this embodiment, the rotor assembly described above is applied to a permanent magnet motor, which helps to increase the cooling effect of the permanent magnet motor.
[0062] In an exemplary embodiment of this application, a vehicle is provided that includes the aforementioned permanent magnet motor to effectively increase the cooling effect, thereby ensuring the performance of the permanent magnet motor while effectively reducing production costs.
[0063] 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. A rotor assembly, characterized in that, include: A rotating shaft, wherein a cooling channel is provided inside the rotating shaft; The rotor core assembly includes at least a stack of first laminations and a stack of second laminations. The first laminations and the second laminations are overlapped and fitted onto the rotating shaft. The first laminations have at least one layer of magnetic steel grooves corresponding to each magnetic pole. A permanent magnet is disposed in each of the magnetic steel grooves. A flow gap for cooling medium to flow is provided between the permanent magnet and the side wall of the magnetic steel groove. The second laminations have axial flow guide grooves and radial flow guide grooves corresponding to each magnetic pole. The radial flow guide grooves connect the cooling channel and the axial flow guide grooves. The axial flow guide grooves connect to each layer of magnetic steel grooves corresponding to the magnetic pole.
2. The rotor assembly according to claim 1, characterized in that, The rotor assembly also includes: A balance disc is disposed on the outer side of both ends of the rotor core assembly along the axial direction. The balance disc is sleeved on the rotating shaft and presses and limits the rotor core assembly. The balance disc is provided with an outlet that communicates with the magnet slot.
3. The rotor assembly according to claim 1, characterized in that, In each layer of magnetic steel grooves corresponding to the same magnetic pole, the outermost radius of at least one layer of magnetic steel groove is greater than the outermost radius of the axial flow guide groove, so that the magnetic steel groove and the axial flow guide groove form a stepped flow path.
4. The rotor assembly according to claim 1, characterized in that, In each layer of magnetic steel grooves corresponding to the same magnetic pole, the outermost layer of magnetic steel groove at least partially overlaps with the axial flow guide groove on the radial width of the first lamination to form a stepped flow channel.
5. The rotor assembly according to claim 1, characterized in that, The axial guide channel includes a long arc side and a short arc side arranged sequentially in the circumferential direction. The long arc side and the short arc side are connected by an arc segment, and the middle part of the long arc side is connected to the radial guide channel.
6. The rotor assembly according to claim 1, characterized in that, The radial guide groove contains a straight flow channel, and the axial guide groove is arranged in a mirror-symmetric manner with the axis of the straight flow channel as the axis of symmetry.
7. The rotor assembly according to claim 1, characterized in that, The first lamination is distributed on both sides of the second lamination and is arranged in a mirror symmetrical manner with the second lamination as the axis of symmetry; or The second laminations are distributed on both sides of the first lamination and are arranged in a mirror-symmetrical manner with the first lamination as the axis of symmetry.
8. The rotor assembly according to claim 2, characterized in that, Multiple first laminations overlap to form a first lamination group. One end of the first lamination group along the axial direction overlaps with the second lamination, and the other end of the first lamination group along the axial direction is pressed and limited by the balance disc.
9. The rotor assembly according to any one of claims 1 to 8, characterized in that, The magnetic groove is equipped with multiple independent permanent magnets.
10. A permanent magnet motor, characterized in that, It includes a stator assembly and a rotor assembly as described in any one of claims 1 to 9.
11. A vehicle, characterized in that, Including the permanent magnet motor as described in claim 10.