Induction rotor comprising a cage with segmented rotor bars
Patent Information
- Application Number
- CN202510831751.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2025-04-23
- Filing Date
- 2025-06-20
- Publication Date
- 2026-10-23
Smart Images
Figure CN122969238A_ABST
Abstract
Description
Technical Field
[0001] The information provided in this section is for the purpose of presenting the general background of this disclosure. To the extent described in this section, the work of the currently named inventors and aspects that may not otherwise be described as prior art at the time of filing are neither explicitly nor implicitly considered as prior art to this disclosure.
[0002] This disclosure relates to electric motors, and more particularly to induction motors, the induction motor including a rotor having a cage including segmented rotor bars. Background Technology
[0003] Electric, hybrid, and fuel cell vehicles typically include an electric motor, a battery system including battery packs, modules, and / or cells, a power inverter, and a battery management system. In some examples, the electric motor includes an induction motor. The stator of an induction motor includes windings that generate a rotating magnetic field. A rotor rotates within the stator and includes rotor laminations having slots formed on their radially outer surfaces. Rotor bars extend longitudinally in the slots in the axial direction. The rotating magnetic field generated by the stator induces an electric field in the rotor bars, which generates a time-varying current in the rotor bars that causes the rotor to rotate and produces a driving torque. Summary of the Invention
[0004] The rotor for an induction motor includes a stack of rotor laminations and a plurality of slots arranged at the radially outer edges of the stack of rotor laminations. The cage includes a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one of the radial and circumferential directions.
[0005] Among other features, the plurality of segmented rotor bars are segmented in the circumferential direction. The plurality of segmented rotor bars are segmented in the radial direction. The plurality of segmented rotor bars in each slot have different cross-sectional areas. The plurality of segmented rotor bars in each slot have a decreasing cross-sectional area in the direction toward the air gap. The plurality of segmented rotor bars include one of an insulating coating and an insulating layer.
[0006] Among other features, spacers are arranged between the plurality of segmented rotor bars. The plurality of segmented rotor bars extend beyond the lamination stack in the axial direction.
[0007] Among other features, the first and second metal end disks are respectively arranged on opposite sides of the laminated stack. The opposite ends of the plurality of segmented rotor bars extend into corresponding cavities in the first and second metal end disks.
[0008] Among other features, the opposing ends of the plurality of segmented rotor bars are welded to first and second metal end discs. The first and second metal end discs have higher mechanical strength than the plurality of segmented rotor bars.
[0009] Among other features, the first and second metal end discs have lower electrical conductivity than the plurality of segmented rotor bars. End caps are cast around the opposite ends of the plurality of segmented rotor bars.
[0010] The induction motor includes a stator, which includes windings. A rotor is arranged inside the stator and includes a stack of rotor laminations. A plurality of slots are arranged adjacent to the radial outer edge of the rotor lamination stack. The cage includes a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one of the radial and circumferential directions.
[0011] Among other features, the plurality of segmented rotor bars are segmented in one of the circumferential and radial directions. The plurality of segmented rotor bars comprise different cross-sectional areas. The plurality of segmented rotor bars in each slot have a decreasing cross-sectional area in the direction toward the air gap. The plurality of segmented rotor bars include an insulating coating.
[0012] Among other features, the first and second metal end discs are arranged on opposite sides of the laminated stack. The plurality of segmented rotor bars extend axially beyond the laminated stack. The opposite ends of the plurality of segmented rotor bars extend into cavities in the first and second metal end discs. The opposite ends of the plurality of segmented rotor bars are welded to the first and second metal end discs.
[0013] Among other features, the induction motor includes first and second end caps. The plurality of segmented rotor bars extend axially beyond the lamination stack. The first and second end caps are cast around the opposite ends of the plurality of segmented rotor bars.
[0014] The vehicle includes an induction motor comprising a stator and a rotor. The stator includes windings, and the rotor includes: a stack of rotor laminations; a plurality of slots arranged adjacent to the radially outer edge of the stack of rotor laminations; and a cage comprising a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one of the radial and circumferential directions. The plurality of segmented rotor bars have different cross-sectional areas. The plurality of segmented rotor bars in each of the slots have a decreasing cross-sectional area in the direction toward the air gap. The vehicle includes a battery system and a power inverter configured to supply power from the battery system to the windings of the induction motor. At least one drive wheel is propelled by the induction motor.
[0015] Option 1. A rotor for an induction motor, comprising:
[0016] Rotor laminations stacked;
[0017] Multiple slots, the multiple slots being arranged adjacent to the radial outer edge of the rotor lamination stack; and
[0018] The cage includes a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one of the radial and circumferential directions.
[0019] Option 2. The rotor according to Option 1, wherein the plurality of segmented rotor bars are segmented in the circumferential direction.
[0020] Option 3. The rotor according to Option 1, wherein the plurality of segmented rotor bars are segmented in the radial direction.
[0021] Option 4. The rotor according to Option 1, wherein the plurality of segmented rotor bars in each of the slots comprises different cross-sectional areas.
[0022] Option 5. The rotor according to Option 1, wherein the plurality of segmented rotor bars in each of the slots have a reduced cross-sectional area in the direction toward the air gap.
[0023] Option 6. The rotor according to Option 1, wherein the plurality of segmented rotor bars include one of an insulating coating and an insulating layer.
[0024] Option 7. The rotor according to Option 1 further includes spacers arranged between the plurality of segmented rotor bars.
[0025] Option 8. The rotor according to Option 1, wherein the plurality of segmented rotor bars extend beyond the lamination stack in the axial direction.
[0026] Option 9. The rotor according to Option 8 further includes:
[0027] A first metal end plate and a second metal end plate are respectively arranged on opposite sides of the stacked laminations.
[0028] The opposite ends of the plurality of segmented rotor bars extend into corresponding cavities in the first and second metal end discs.
[0029] Option 10. The rotor according to Option 9, wherein the opposite ends of the plurality of segmented rotor bars are welded to the first and second metal end discs.
[0030] Option 11. The rotor according to Option 9, wherein the first metal end plate and the second metal end plate have higher mechanical strength than the plurality of segmented rotor bars.
[0031] Option 12. The rotor according to Option 9, wherein the first metal end plate and the second metal end plate have lower electrical conductivity than the plurality of segmented rotor bars.
[0032] Option 13. The rotor according to Option 8 further includes end caps cast around the opposite ends of the plurality of segmented rotor bars.
[0033] Option 14. An induction motor, comprising:
[0034] Stator, the stator including windings; and
[0035] Rotor, the rotor being arranged inside the stator and comprising:
[0036] Rotor laminations stacked;
[0037] Multiple slots, the multiple slots being arranged adjacent to the radial outer edge of the rotor lamination stack; and
[0038] The cage includes a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one of the radial and circumferential directions.
[0039] Option 15. The induction motor according to Option 14, wherein the plurality of segmented rotor bars are segmented in one of the circumferential and radial directions.
[0040] Option 16. The induction motor according to Option 14, wherein:
[0041] The multiple segmented rotor bars include different cross-sectional areas, and
[0042] The plurality of segmented rotor bars in each of the slots have a reduced cross-sectional area in the direction toward the air gap.
[0043] Option 17. The induction motor according to Option 14, wherein the plurality of segmented rotor bars include an insulating coating.
[0044] Option 18. The induction motor according to Option 14 further includes:
[0045] A first metal end plate and a second metal end plate are arranged on opposite sides of the stacked wafers.
[0046] The plurality of segmented rotor bars extend beyond the stack of laminations in the axial direction.
[0047] The opposing ends of the plurality of segmented rotor bars extend into cavities in the first and second metal end discs, and
[0048] The opposite ends of the plurality of segmented rotor bars are welded to the first and second metal end discs.
[0049] Option 19. The induction motor according to Option 14 further includes:
[0050] First and second end caps,
[0051] Wherein, the plurality of segmented rotor bars extend beyond the stack of laminations in the axial direction, and
[0052] The first and second end caps are cast around the opposite ends of the plurality of segmented rotor bars.
[0053] Option 20. A vehicle comprising:
[0054] An induction motor, the induction motor comprising:
[0055] Stator, the stator including windings; and
[0056] Rotor, the rotor comprising:
[0057] Rotor laminations stacked;
[0058] Multiple slots, the multiple slots being arranged adjacent to the radial outer edge of the rotor lamination stack; and
[0059] The cage comprises a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one direction, in the radial and circumferential directions.
[0060] The plurality of segmented rotor bars have different cross-sectional areas, and
[0061] The plurality of segmented rotor bars in each of the slots have a reduced cross-sectional area in the direction toward the air gap;
[0062] Battery system;
[0063] A power inverter configured to supply power from a battery system to the windings of an induction motor; and
[0064] At least one drive wheel propelled by an induction motor.
[0065] Other areas of application of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description
[0066] This disclosure will be understood more fully from the detailed description and accompanying drawings, in which:
[0067] Figure 1The present disclosure provides a functional block diagram of an example vehicle, which includes an induction motor having a rotor comprising laminated plates and segmented rotor bars.
[0068] Figure 2A and Figure 2B This is a side cross-section of an example of an induction motor including a rotor with segmented rotor bars according to the present disclosure;
[0069] Figure 2C and Figure 2D These are side views of examples of rotors having non-skewed segmented rotor bars and skewed segmented rotor bars according to this disclosure;
[0070] Figure 3 This is a front view of an example of a portion of a rotor lamination according to this disclosure;
[0071] Figure 4 This is a front view of an example portion of a rotor including laminated and segmented rotor bars according to this disclosure;
[0072] Figure 5A and Figure 5B This is a front view of an example of a rotor bar segmented in the radial direction according to this disclosure;
[0073] Figure 5C This is a front view of a segmented rotor bar encapsulated in epoxy resin or varnish in slots within a stack of laminations, according to the present disclosure.
[0074] Figure 5D It is a front view including a section of tightly bundled conductors;
[0075] Figure 6 This is a front view of another example of a rotor bar segmented in the circumferential direction according to this disclosure.
[0076] In the accompanying drawings, reference numerals may be used repeatedly to identify similar and / or identical elements. Detailed Implementation
[0077] Although this article describes rotors and induction motors including rotors in the context of vehicles, induction motors can be used in stationary or other applications.
[0078] The induction motor according to this disclosure includes a rotor comprising laminations defining slots extending to or adjacent to the radially outer edge of the laminations. The rotor includes a squirrel cage or cage defined by a plurality of rotor bars located in slots positioned around the radially outer edge of the laminations. According to this disclosure, the plurality of rotor bars are segmented in the circumferential and / or radial directions to reduce AC induction losses at high speeds (compared to a monolithic rotor bar). In some examples, the opposing ends of the plurality of segmented rotor bars extend beyond the laminations and are cast into end caps or welded to one or more planar end plates to short-circuit the ends of the segmented rotor bars. The end caps or end plates provide a return current path for the plurality of segmented rotor bars.
[0079] In some examples, the segments of the segmented rotor bar have cross-sections with different shapes (in a plane transverse to the axial direction), thereby producing conductors with different cross-sectional areas. In some examples, the segments of the segmented rotor bar have a segmented pattern defined by segments having conductor cross-sectional areas that decrease in the direction toward the air gap between the stator and rotor.
[0080] End plates are welded / attached to the opposing axial ends of the segmented rotor bars to short-circuit the individual segments and bars. In some examples, the end plates are made of a conductor alloy that is mechanically stronger than the segmented rotor bars to increase mechanical strength. In some examples, the segments of the segmented rotor bars use conductors with higher conductivity than the end plates.
[0081] In some examples, segments of the segmented rotor bar are inserted into slots in the rotor laminations. End plates are then mounted on and welded to the opposing ends of the segmented rotor bar. In some examples, multiple end plates are used at each end. In some examples, one end plate is mounted at a time, and welding is performed between each end plate along the edge of the segmented rotor bar. Alternatively, after the end plates are mounted, the end plates and the segmented rotor bar are circumferentially welded between them. In other examples, end caps are cast onto the opposing ends of the segmented rotor bar.
[0082] Now for reference Figure 1 The vehicle 10 includes one or more induction motors 16 that drive one or more wheels of the vehicle 10. Each induction motor 16 includes a rotor comprising laminated and segmented rotor bars, as will be further described below. A battery system 12 outputs power to the one or more induction motors 16 via a power inverter 14 to generate drive torque. A battery management system 17 controls the power inverter 14 based on driver input and / or sensed battery, inverter, and / or motor parameters. The induction motors 16 may be directly coupled to the wheels 20 of the vehicle 10, or a drivetrain 18 may be used.
[0083] Now for reference Figures 2A to 2D The induction motor 16 includes a stator 60, and the stator 60 includes windings 64. Figure 2A In this configuration, rotor 70 is arranged inside a cylindrical cavity defined by stator 60. Air gap 66 is defined between the radially outer surface of rotor 70 and the radially inner surface of stator 60. Rotor 70 and shaft 82 rotate relative to stator 60.
[0084] The rotor 70 includes a stack of rotor laminations 71 defining radial slots located adjacent to their radially outer edges. The rotor 70 includes a plurality of segmented rotor bars 72 and end caps or discs located at opposite axial ends of the rotor 70. Figure 2A In the middle, end caps 74 are cast around the axial ends of the plurality of segmented rotor bars 72. Figure 2B In this configuration, the plurality of segmented rotor bars 72 pass through alignment cavities in one or more planar end plates 77. In some examples, the plurality of segmented rotor bars 72 are welded to one or more planar end plates 77 along their circumferential edges between them. In other examples, each of the one or more planar end plates 77 is assembled and then welded around the outer edges of the plurality of segmented rotor bars 72 on the exposed outer surfaces (and then the process is repeated for the next end plate, and so on).
[0085] exist Figure 2C In this configuration, rotor 70 includes non-skewed segmented rotor bars 72. In other words, the segmented rotor bars 72 extend along a line parallel to the axial direction. Figure 2D In this rotor 70, segmented rotor bars 72 are skewed at a skew angle. In other words, the segmented rotor bars 72 extend at an angle relative to a line parallel to the axial direction.
[0086] Now for reference Figure 3 The laminations 110 of the rotor 70 include slots 114 configured to receive segmented rotor bars. The laminations 110 can span 360° / L, where L is an integer (e.g., in...). Figure 3 In some examples, the laminations 110 are made of electrical steel (such as silicon steel or cobalt steel). In some examples, the segmented rotor bars are made of pure copper, pure aluminum, or an alloy of copper and aluminum. In some examples, the slot 114 includes an opening 115 at its radially outer end, the opening being configured to engage the segmented rotor bar. For example, Figure 3 The circumferential opening 115 is narrower than the width of the segmented rotor bar in the circumferential direction to mechanically hold the segmented rotor bar in place. In other examples, the radially outer ends are surrounded by laminations, such as... Figure 5C As shown in the image.
[0087] Now for reference Figure 4The segmented rotor bars 120 are arranged in slots 114 of the laminations 110 of the rotor 70. In some examples, the segmented rotor bars 120 are segmented in the radial direction. For example, the segmented rotor bars 120 include rotor bar segments 120-1, 120-2, ..., and 120-R, where R is an integer greater than 1. Figure 4 In this case, R=4, although additional or fewer segments may be used.
[0088] In some examples, each of the rotor bar segments 120-1, 120-2, ..., and 120-R has a decreasing cross-sectional area (in a plane transverse to the axial direction) in the direction toward the air gap. In some examples, the segmented rotor bars 120 include an insulating coating or insulating layer 125. The insulating coating or insulating layer 125 is masked or mechanically removed to allow attachment to end caps or end discs. In some examples, the segmented rotor bars 120 are encapsulated with varnish, epoxy, or other coatings to mechanically hold them in place in the slots 114. In some examples, the segmented rotor bars 120 rely on high contact resistance between the segments for insulation. Each of the rotor bar segments 120-1, 120-2, ..., and 120-R contacts and is tightly bound to an adjacent rotor bar segment of the same segment.
[0089] Now for reference Figure 5A and Figure 5B An example of a segmented rotor bar segmented in the radial direction is shown. Figure 5A In this configuration, the segmented rotor bar 140 includes rotor bar segments 142-1, 142-2, 142-3, and 142-4. In some examples, rotor bar segments 142-1, 142-2, 142-3, and 142-4 are coated with an insulating coating or insulating layer 144. Figure 5B In the middle, spacers 164 are arranged between rotor bar sections 142-1, 142-2, 142-3 and 142-4 to create an air gap.
[0090] exist Figure 5C In this configuration, the rotor bar 170 is encapsulated in epoxy resin or varnish 171 within slots in the lamination 110. In some examples, segmented rotor bars are encapsulated in epoxy resin or varnish 171, wherein the rotor bar segments are spaced apart (shown), insulated, and / or in direct contact.
[0091] like Figures 5A to 5C As shown, the segment can be a solid conductor. Figure 5DIn this configuration, a segment (such as segment 142-3) may comprise a plurality of tightly bundled wire conductors 149 having a predetermined external shape corresponding to one of the segments. In some examples, the external shape is trapezoidal, teardrop-shaped, or other suitable shape. The wire conductors 149 are wound and compacted to form the shape of one of the segments. In some examples, all segments are inserted together into the rotor slot (rather than inserting individual segments). In some examples, each of the wire conductors includes a thin insulating coating.
[0092] Now for reference Figure 6 The segmented rotor bar 180 includes rotor bar segments 184-1 and 184-2, which are segmented in the circumferential direction in a plane transverse to the axial direction. In some examples, rotor bar segments 184-1 and 184-2 have a width that increases radially toward the air gap.
[0093] The foregoing description is illustrative in nature and is in no way intended to limit this disclosure, its application, or use. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the drawings, specification, and appended claims. It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, while each of the embodiments described above is described as having certain features, any one or more of those features described with reference to any embodiment of this disclosure may be implemented in and / or combined with features of any other embodiment, even if such combinations are not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitutions of one or more embodiments for each other remain within the scope of this disclosure.
[0094] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including “connected,” “joined,” “linked,” “adjacent,” “next to,” “on top,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when describing the relationship between first and second elements in the above disclosure, the relationship can be a direct relationship in which no other intermediate elements exist between the first and second elements, or an indirect relationship in which one or more intermediate elements exist between the first and second elements (spatially or functionally). As used herein, the phrase “at least one of A, B, and C” should be interpreted as meaning logic using the non-exclusive logic “OR” (A or B or C) and should not be interpreted as meaning “at least one of A, at least one of B, and at least one of C.”
Claims
1. A rotor for an induction motor, comprising: Rotor laminations stacked; Multiple slots are arranged adjacent to the radial outer edge of the rotor lamination stack; as well as The cage includes a plurality of segmented rotor bars arranged in the plurality of slots and segmented in at least one of the radial and circumferential directions.
2. The rotor according to claim 1, wherein, The multiple segmented rotor bars are segmented in the circumferential direction.
3. The rotor according to claim 1, wherein, The multiple segmented rotor bars are segmented in the radial direction.
4. The rotor according to claim 1, wherein, The plurality of segmented rotor bars in each of the slots comprise different cross-sectional areas.
5. The rotor according to claim 1, wherein, The plurality of segmented rotor bars in each of the slots have a reduced cross-sectional area in the direction toward the air gap.
6. The rotor according to claim 1, wherein, The plurality of segmented rotor bars include one of an insulating coating and an insulating layer.
7. The rotor according to claim 1, further comprising spacers arranged between the plurality of segmented rotor bars.
8. The rotor according to claim 1, wherein, The plurality of segmented rotor bars extend beyond the stack of laminations in the axial direction.
9. The rotor according to claim 8, further comprising: A first metal end plate and a second metal end plate are respectively arranged on opposite sides of the stacked laminations. The opposite ends of the plurality of segmented rotor bars extend into corresponding cavities in the first and second metal end discs.
10. The rotor according to claim 9, wherein, The opposite ends of the plurality of segmented rotor bars are welded to the first and second metal end discs.