Electric machine rotor, electric machine, electric drive and vehicle
By employing a novel torsional method using V-shaped or linear rotor segments in the motor rotor, the noise and vibration problems caused by torque fluctuations are solved, thus improving the vehicle's NVH performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- VALEO NEW ENERGY VEHICLES GERMANY GMBH
- Filing Date
- 2024-12-02
- Publication Date
- 2026-06-02
AI Technical Summary
Existing motor rotor torsion methods are insufficient to effectively suppress torque fluctuations, resulting in inadequate solutions to vehicle noise, vibration, and harshness (NVH) problems.
A novel V-shaped rotor segment group torsion method is adopted, which forms a V-shaped or linear rotor segment group by torturing multiple rotor segments of the motor rotor in different directions, thereby reducing torque fluctuation.
It significantly reduces the noise during motor operation and improves the vehicle's NVH performance, especially reducing the noise related to the tooth structure by about 5 decibels.
Smart Images
Figure CN122137144A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to an electric motor rotor. This disclosure also relates to an electric motor including such an electric motor rotor, an electric drive device including said electric motor, and a vehicle including said electric drive device. Background Technology
[0002] Both the rotor and stator of an electric motor have a slotted structure. The stator windings are housed in stator slots, where alternating current generates a rotating magnetic field. The rotor magnets (such as permanent magnets) are housed in rotor slots or holes, generating circumferentially distributed magnetic poles. Under the influence of the stator's rotating magnetic field, these poles produce a torque that drives the rotor to rotate. Because the number of rotor poles and stator slots is finite, the torque experienced by the rotor during rotation is not constant but fluctuates. This torque fluctuation causes vibration and noise within the motor itself. In particular, for vehicles driven by electric motors, the motor's torque fluctuations can cause overall vehicle noise, vibration, and acoustic harshness (NVH) problems.
[0003] In existing electric motors, the rotor is typically divided into multiple sections. These sections can be twisted relative to each other at a predetermined angle, causing the rotor's magnetic poles to tilt. This tilting causes the torque fluctuations experienced by different sections of the rotor to become asynchronous, staggered in time or phase. Consequently, the torque fluctuations between sections can partially cancel each other out, reducing the overall torque fluctuation of the rotor. Existing rotor section twisting methods include: twisting different sections of the rotor sequentially along the same circumferential direction; and having two sections located at the center of the rotor not twisted relative to each other, while the sections on either side twist sequentially relative to the two central sections along different circumferential directions.
[0004] However, existing rotor torsion methods are still insufficient to meet the ever-increasing demands for vehicle NVH (noise, vibration, and harshness). Therefore, there is an urgent need for a novel rotor section torsion method to effectively suppress motor torque fluctuations and improve vehicle NVH performance. Summary of the Invention
[0005] Therefore, this disclosure aims to solve the above-mentioned problems, and its object is to provide an electric motor rotor, an electric motor including such an electric motor rotor, an electric drive device including such an electric motor, and a vehicle including such an electric drive device. The electric motor rotor according to this disclosure has a novel rotor segment torsion mode, which can effectively suppress torque fluctuations of the motor, reduce vibrations and noise caused by torque fluctuations, and thereby improve the NVH performance of the vehicle.
[0006] The objective is achieved by a motor rotor according to an embodiment of the present disclosure, the motor rotor comprising a plurality of rotor segments arranged side-by-side in an axial direction parallel to the central axis of the motor rotor, each rotor segment having one or more magnetic poles arranged in a circumferential direction around the central axis. The motor rotor includes one or more V-shaped rotor segment groups, each V-shaped rotor segment group being formed by three consecutive rotor segments, wherein the magnetic pole of the middle rotor segment of the V-shaped rotor segment group is twisted by an angle θ in a torsional direction relative to the zero-position of the motor rotor, and the magnetic poles of the two end rotor segments of the V-shaped rotor segment group are twisted by an angle θ in a torsional direction opposite to that of the middle rotor segment relative to the zero-position.
[0007] One objective of this disclosure is to provide a motor rotor with a novel rotor segment torsion method that effectively suppresses torque fluctuations in the motor and reduces vibrations and noise caused by these fluctuations. The motor rotor according to this disclosure comprises a V-shaped rotor segment group with three rotor segments, wherein the middle rotor segment and the end rotor segments are twisted in opposite directions with the same torsion angle θ relative to the zero-position of the motor rotor. Through simulation and experimental measurements, the inventors of this disclosure have found that, compared to motors with rotors twisted using existing torsion methods, the motor rotor according to this disclosure, by employing such a V-shaped rotor segment group, can significantly reduce the noise generated during motor operation. In particular, the noise associated with the toothed structure can be reduced by approximately 5 decibels.
[0008] The motor rotor according to this disclosure may also have one or more of the following features, individually or in combination.
[0009] According to one embodiment of this disclosure, the motor rotor includes at least a first V-shaped rotor segment group and a second V-shaped rotor segment group.
[0010] According to one embodiment of this disclosure, the first V-shaped rotor segment group and the second V-shaped rotor segment group do not include a shared rotor segment.
[0011] According to one embodiment of this disclosure, the magnetic poles of the intermediate rotor sections of the first V-shaped rotor section group and the second V-shaped rotor section group are twisted in the same torsional direction relative to the zero azimuth position.
[0012] According to one embodiment of this disclosure, the magnetic poles of the intermediate rotor segments of the first V-shaped rotor segment group and the second V-shaped rotor segment group are twisted in different torsional directions relative to the zero azimuth position (z).
[0013] According to one embodiment of this disclosure, the first V-shaped rotor segment group and the second V-shaped rotor segment group share two rotor segments, such that the middle rotor segment of the first V-shaped rotor segment group constitutes an end rotor segment of the second V-shaped rotor segment group, and the end rotor segment of the first V-shaped rotor segment group constitutes the middle rotor segment of the second V-shaped rotor segment group.
[0014] According to one embodiment of this disclosure, the first V-shaped rotor section group and the second V-shaped rotor section group share a common end rotor section.
[0015] According to one embodiment of the present disclosure, the motor rotor further includes a separate rotor section adjacent to an end rotor section of a V-shaped rotor section group but not belonging to any V-shaped rotor section group, wherein the magnetic pole of the separate rotor section is twisted by an angle 2θ relative to the magnetic pole of the end rotor section, and the twisting direction is the same as the twisting direction of the magnetic pole of the end rotor section relative to the zero position.
[0016] According to one embodiment of this disclosure, the magnetic poles of any two adjacent rotor segments in the plurality of rotor segments are twisted by an angle θ relative to the zero azimuth position in opposite torsional directions.
[0017] According to one embodiment of the present disclosure, the motor rotor includes a linear rotor segment group formed by a continuous plurality of rotor segments, wherein the magnetic poles of each rotor segment in the linear rotor segment group are linearly inclined, and the motor rotor includes a plurality of linear rotor segment groups arranged discontinuously and in parallel.
[0018] According to one embodiment of this disclosure, the motor rotor includes six rotor sections.
[0019] According to one embodiment of this disclosure, the maximum angle of rotation of the magnetic poles of multiple rotor sections of the motor rotor relative to the zero azimuth position along different torsional directions is equal.
[0020] This disclosure also relates to an electric motor that includes an electric motor rotor as described above.
[0021] This disclosure also relates to an electric drive device comprising the motor described above.
[0022] This disclosure also relates to a vehicle that includes the electric drive unit described above. Attached Figure Description
[0023] The above and other features and advantages of this disclosure will become more apparent from the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings, which are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. The following drawings are not intentionally drawn to scale with actual dimensions; their focus is on illustrating the gist of this disclosure.
[0024] Figure 1A An exemplary arrangement of the rotor section of the motor rotor is shown;
[0025] Figure 1B yes Figure 1A A simplified schematic diagram showing the V-shaped rotor section group;
[0026] Figure 2A Another exemplary arrangement of the rotor section of the motor rotor is shown;
[0027] Figure 2B yes Figure 2A A simplified schematic diagram showing the V-shaped rotor section group;
[0028] Figure 3A This illustrates yet another exemplary arrangement of the rotor section of the motor rotor;
[0029] Figure 3B yes Figure 3A A simplified schematic diagram showing the V-shaped rotor section group;
[0030] Figure 3C yes Figure 3A Another simplified schematic diagram shows a group of linear rotor sections.
[0031] In each figure, identical or similar parts are represented by the same reference numerals. Detailed Implementation
[0032] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure.
[0033] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “a,” “an,” or “the,” and similar words used in this patent application specification and claims do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising,” “including,” or similar words mean that the element or object preceding the word encompasses the element or object listed following the word and its equivalents, without excluding other elements or objects. The terms “first,” “second,” and similar words used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. “Upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes. The terms “axial” and “axial direction” refer to the direction of extension of the central axis X; the terms “radial” and “radial direction” are directions orthogonal to the central axis X; and the terms “circumferential” and “circumferential direction” are circumferential directions about the central axis X. The zero-position angle of the motor rotor refers to the angular position of the magnetic poles when there is no twisting in any section of the rotor. It corresponds to the initial angular position of the rotor when it is attracted by the stator magnetic field when the stator winding is energized with DC.
[0034] Various embodiments according to this disclosure will be described in detail with reference to the accompanying drawings. It should be noted that, in the drawings, the same reference numerals are assigned to components having substantially the same or similar structure and function, and repeated descriptions of them will be omitted.
[0035] Figure 1A The motor rotor 10 of the first embodiment of this disclosure is shown. Figure 1B yes Figure 1A A simplified schematic diagram of the motor rotor 10 is shown.
[0036] like Figure 1A As shown, the motor rotor 10 includes six rotor segments s arranged side-by-side along an axial direction parallel to the central axis X, namely rotor segments s1-s6. It is understood that the number of rotor segments included in the motor rotor 10 may be more or less than six. Each rotor segment s may include multiple rotor slots, which house permanent magnets or other magnetic elements, forming one or more magnetic poles P arranged in the circumferential direction, preferably multiple magnetic poles P evenly distributed circumferentially. Figure 1A The diagram illustrates a magnetic pole P relative to the initial angular position for each rotor segment s.
[0037] exist Figure 1A and Figure 1BIn the illustrated embodiment, each rotor segment s is twisted relative to its initial angular position to reduce torque fluctuations caused by the motor's cogging structure. This twisting causes the magnetic pole P of each rotor segment to rotate by a certain angle relative to its zero-position angular position z. Figure 1B The torsion of magnetic pole P relative to the zero angular position z is shown in a simplified view.
[0038] Specifically, such as Figure 1A and Figure 1B As shown, rotor segments s1, s2, and s3 constitute a V-shaped rotor segment group, namely the first V-shaped rotor segment group. Rotor segment s2 is the middle rotor segment of this first V-shaped rotor segment group, and its magnetic pole P is twisted by an angle θ relative to the zero position z in a torsional direction. Rotor segments s1 and s3 are the two end rotor segments of this V-shaped rotor segment group, and their magnetic pole P is twisted by an angle θ relative to the zero position z in a torsional direction opposite to that of rotor segment s2.
[0039] Similarly, rotor segments s4, s5, and s6 also constitute a V-shaped rotor segment group, namely the second V-shaped rotor segment group. In this second V-shaped rotor segment group, rotor segment s5 is the middle rotor segment, and its magnetic pole P is twisted by an angle θ relative to the zero position z along the same torsional direction as the middle rotor segment s2 of the first V-shaped rotor segment. Rotor segments s4 and s6 are the two end rotor segments, and their magnetic pole P is twisted by an angle θ relative to the zero position z along the opposite torsional direction as rotor segment s5.
[0040] exist Figure 1A and Figure 1B In the illustrated embodiment, the six rotor segments of the motor rotor 10 form two V-shaped rotor segment groups, and the middle rotor segment of these two V-shaped rotor segment groups twists in the same torsional direction. That is, the orientation of the magnetic poles P of each rotor segment of the motor rotor 10 forms a double-V structure in the same direction. Figure 1B The direction of the magnetic pole P is shown by a dashed line.
[0041] Figure 2A The motor rotor 10 of the second embodiment of this disclosure is shown. Figure 2B yes Figure 2A The diagram shows a simplified schematic of the motor rotor 10. The following description of the second embodiment will focus on the parts that differ from the first embodiment, while omitting detailed descriptions of the parts that are the same in both.
[0042] Similar to the first embodiment, the motor rotor 10 according to the second embodiment also includes six rotor segments s, namely rotor segments s1-s6. Rotor segments s1, s2, and s3 form a first V-shaped rotor segment group, and rotor segments s4, s5, and s6 form a second V-shaped rotor segment group. Unlike the first embodiment, the magnetic pole P of the middle rotor segment s2 in the first V-shaped rotor segment group and the magnetic pole P of the middle rotor segment s5 in the second embodiment are twisted by an angle θ in opposite torsional directions relative to their zero-position positions. That is, in the second embodiment, the six rotor segments of the motor rotor 10 form two V-shaped rotor segment groups, and the middle rotor segments of these two V-shaped rotor segment groups are twisted in opposite torsional directions. Specifically, the orientation of the magnetic pole P of each rotor segment of the motor rotor 10 forms a reverse double-V structure. Figure 2B The direction of the magnetic pole P is shown by a dashed line.
[0043] Furthermore, in the second embodiment, when s1, s2, and s3 constitute the first V-shaped rotor segment group, rotor segments s2, s3, and s4 also constitute a V-shaped rotor segment group (the second V-shaped rotor segment group). Specifically, rotor segment s3 is the middle rotor segment of this second V-shaped rotor segment group, and rotor segments s2 and s4 are the two end rotor segments of this second V-shaped rotor segment group. The magnetic poles P of the middle and end rotor segments are twisted by an angle θ relative to their zero-position angle z along opposite torsional directions. This second V-shaped rotor segment group shares two rotor segments, s2 and s3, with the end rotor segment s3 of the first V-shaped rotor segment group constituting the middle rotor segment of the second V-shaped rotor segment group. Similarly, rotor segments s3, s4, and s5 constitute the third V-shaped rotor segment group, and rotor segments s4, s5, and s6 constitute the fourth V-shaped rotor segment group. The two adjacent V-shaped rotor sections in these V-shaped rotor section groups are oriented in opposite directions.
[0044] In the second embodiment, when rotor segments s1, s2, and s3 constitute the first V-shaped rotor segment group, rotor segments s3, s4, and s5 also constitute a V-shaped rotor segment group (the second V-shaped rotor segment group). Specifically, rotor segment s4 is the middle rotor segment of this second V-shaped rotor segment group, and rotor segments s3 and s5 are the two end rotor segments of this second V-shaped rotor segment group. The magnetic poles P of the middle and end rotor segments are twisted by an angle θ relative to their zero-position angle z along opposite torsional directions. This second V-shaped rotor segment group shares an end rotor segment, s3, with the first V-shaped rotor segment group. Similarly, rotor segments s4, s5, and s6 constitute the third V-shaped rotor segment group. All these V-shaped rotor segment groups are oriented in the same direction.
[0045] Furthermore, in the second embodiment, such as Figure 2BAs shown, the magnetic poles P of the rotor sections s1 and s2, s2 and s3, s3 and s4, s4 and s5, and s5 and s6 of the motor rotor 10 are arranged alternately on both sides of the zero azimuth position z, and are twisted by an angle θ in opposite directions. That is, the torsion of the motor rotor 10 can be set such that the magnetic poles P of any two adjacent rotor sections are twisted by an angle θ on both sides of the zero azimuth position z.
[0046] Figure 3A The motor rotor 10 of the third embodiment of this disclosure is shown. Figure 3B and Figure 3C yes Figure 3A The diagram shows a simplified schematic of the motor rotor 10. The following description of the third embodiment will focus on the parts that differ from the first and second embodiments, while detailed descriptions of the same parts will be omitted.
[0047] According to the third embodiment, the motor rotor 10 also includes six rotor segments s, namely rotor segments s1-s6. Rotor segments s2, s3, and s4 constitute a first V-shaped rotor segment group, and rotor segments s3, s4, and s5 constitute a second V-shaped rotor segment group. Unlike the first and second embodiments, rotor segments s1 and s6 do not belong to any V-shaped rotor segment group, but instead form separate rotor segments. The magnetic pole P of the separate rotor segment s1 is twisted by an angle 2θ relative to the magnetic pole P of the end rotor segment s2 of the first V-shaped rotor segment group, and the direction of twisting is the same as the direction of twisting of the magnetic pole P of the end rotor segment s2 relative to the zero-position angle z. The magnetic pole P of the separate rotor segment s6 is twisted by an angle 2θ relative to the magnetic pole P of the end rotor segment s5 of the second V-shaped rotor segment group, and the direction of twisting is the same as the direction of twisting of the magnetic pole P of the end rotor segment s5 relative to the zero-position angle z.
[0048] Furthermore, in the third embodiment, the six rotor segments s1-s6 of the motor rotor 10 can also be grouped in other ways. Figure 3C A simplified schematic diagram showing grouping by linear rotor segment groups is shown.
[0049] As shown in the figure, the magnetic pole P of rotor segment s1 has a torsional angle of 3θ relative to the zero azimuth position z, the magnetic pole P of rotor segment s2 has a torsional angle of θ relative to the zero azimuth position z, and the magnetic pole P of rotor segment s3 has a torsional angle of -θ relative to the zero azimuth position z. Therefore, the magnetic pole P of rotor segments s1, s2, and s3 are linearly inclined, forming the first linear rotor segment group. Similarly, the magnetic pole P of rotor segment s4 has a torsional angle of θ relative to the zero azimuth position z, the magnetic pole P of rotor segment s5 has a torsional angle of -θ relative to the zero azimuth position z, and the magnetic pole P of rotor segment s6 has a torsional angle of -3θ relative to the zero azimuth position z. Therefore, the linearly inclined magnetic pole P of rotor segments s4, s5, and s6 form the second linear rotor segment group. Compared with existing linearly torsional rotors, the first and second linear rotor segment groups constitute two discontinuous and parallel linear segments.
[0050] The above description, in conjunction with the accompanying drawings, describes three embodiments of the rotor section torsion method of the motor rotor 10 according to the present disclosure. Simulation and experimental measurements have shown that, compared to motors using existing torsion methods, the motor rotor according to the present disclosure can suppress motor torque fluctuations to a greater extent, reduce noise generated during motor operation, and improve vehicle NVH performance. In particular, noise associated with the toothed structure can be reduced by approximately 5 decibels.
[0051] It can also be noted that in the first and second embodiments, the maximum angle of rotation of the magnetic pole P relative to the zero position z along both the positive and negative rotation directions is θ. In the third embodiment, the maximum angle of rotation of the magnetic pole P relative to the zero position z along both the positive and negative rotation directions is 3θ. That is to say, the maximum angle of rotation of the magnetic pole P relative to the zero position z along different rotation directions in each rotor section s of the motor rotor 10 is equal.
[0052] According to another aspect of this disclosure, an electric motor is proposed, which includes an electric motor rotor as described above.
[0053] According to another aspect of this disclosure, an electric drive device is proposed, which includes a motor as described above.
[0054] According to another aspect of this disclosure, a vehicle is proposed that includes the electric drive unit as described above. The vehicle can be an electrified vehicle, such as a battery electric vehicle (BEV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a range-extended electric vehicle (REEV), or a fuel cell electric vehicle (FCEV). The vehicle can also be a hydrogen fuel cell vehicle.
[0055] Certain features, structures, or characteristics in one or more embodiments of this disclosure may be appropriately combined.
[0056] The foregoing description is illustrative of the present disclosure and should not be construed as limiting it. While several exemplary embodiments of the present disclosure have been described, those skilled in the art will readily understand that many modifications may be made to the exemplary embodiments without departing from the novel teachings and advantages of the present disclosure. Therefore, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims. It should be understood that the foregoing description is illustrative of the present disclosure and should not be construed as limiting it to the specific embodiments disclosed, and modifications to the disclosed embodiments and other embodiments are intended to be included within the scope of this disclosure.
Claims
1. A motor rotor (10), characterized in that, The motor rotor (10) includes a plurality of rotor segments (s) arranged side by side in an axial direction parallel to the central axis (X) of the motor rotor (10), each rotor segment (s) having one or more magnetic poles (P) arranged in a circumferential direction around the central axis (X). The motor rotor (10) includes one or more V-shaped rotor segment groups, which are formed by three consecutive rotor segments (s). The magnetic pole (P) of the middle rotor segment of the V-shaped rotor segment group is twisted by an angle θ relative to the zero position (z) of the motor rotor (10) along a torsional direction. The magnetic pole (P) of the two end rotor segments of the V-shaped rotor segment group is twisted by an angle θ relative to the zero position (z) along a torsional direction opposite to that of the middle rotor segment.
2. The motor rotor (10) according to claim 1, characterized in that, The motor rotor (10) includes at least a first V-shaped rotor section group and a second V-shaped rotor section group.
3. The motor rotor (10) according to claim 2, characterized in that, The first V-shaped rotor section group and the second V-shaped rotor section group do not include the shared rotor section (s).
4. The motor rotor (10) according to claim 3, characterized in that, The magnetic poles (P) of the intermediate rotor sections of the first V-shaped rotor section group and the second V-shaped rotor section group are twisted in the same torsional direction relative to the zero azimuth position (z).
5. The motor rotor (10) according to claim 3, characterized in that, The magnetic poles (P) of the intermediate rotor segments (s) of the first V-shaped rotor segment group and the second V-shaped rotor segment group are twisted in different torsional directions relative to the zero azimuth position (z).
6. The motor rotor (10) according to claim 2, characterized in that, The first V-shaped rotor segment group and the second V-shaped rotor segment group share two rotor segments (s), such that the middle rotor segment (s) of the first V-shaped rotor segment group constitutes an end rotor segment (s) of the second V-shaped rotor segment group, and the end rotor segment (s) of the first V-shaped rotor segment group constitutes the middle rotor segment (s) of the second V-shaped rotor segment group.
7. The motor rotor (10) according to claim 2, characterized in that, The first V-shaped rotor section group and the second V-shaped rotor section group share a single end rotor section (s).
8. The motor rotor (10) according to any one of claims 1 to 7, characterized in that, The motor rotor (10) also includes a separate rotor section that is adjacent to an end rotor section (s) of a V-shaped rotor section group but does not belong to any V-shaped rotor section group. The magnetic pole (P) of the separate rotor section is twisted by an angle 2θ relative to the magnetic pole (P) of the end rotor section (s), and the twisting direction is the same as the twisting direction of the magnetic pole (P) of the end rotor section (s) relative to the zero position angle (z).
9. The motor rotor (10) according to claim 1 or 2, characterized in that, The magnetic poles (P) of any two adjacent rotor segments (s) in the plurality of rotor segments (s) are twisted by an angle θ relative to the zero position (z) in opposite torsional directions.
10. The motor rotor (10) according to claim 1, characterized in that, The motor rotor (10) comprises a linear rotor segment group formed by a series of rotor segments (s), wherein the magnetic pole (P) of each rotor segment (s) in the linear rotor segment group is linearly inclined, and The motor rotor (10) comprises multiple linear rotor segments arranged intermittently and in parallel.
11. The motor rotor (10) according to any one of claims 1 to 7, characterized in that, The motor rotor (10) comprises 6 rotor sections (s).
12. The motor rotor (10) according to any one of claims 1 to 7, characterized in that, The maximum angle of rotation of the magnetic poles (P) of multiple rotor sections (s) of the motor rotor (10) relative to the zero position (z) along different torsional directions is equal.
13. An electric motor, characterized in that, The motor includes a motor rotor (10) according to any one of claims 1 to 12.
14. An electric drive device, characterized in that, The electric drive device includes at least the motor according to claim 13.
15. A vehicle, characterized in that, The vehicle includes the electric drive unit according to claim 14.