Winding overhang guide, wound rotor of an electric machine, and electric machine including such a wound rotor
The winding overhang guide with radial ribs and guide pins addresses the issue of wire fatigue and breakage in wound rotors by providing radial retention, enabling higher rotational speeds while maintaining cost-effectiveness.
Patent Information
- Application Number
- JP2025546718
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-02-14
- Filing Date
- 2024-02-05
- Publication Date
- 2026-02-16
AI Technical Summary
Existing wound rotors in rotating electric machines experience damage to winding wires due to centrifugal forces during high rotational speeds, leading to fatigue and breakage, particularly between adjacent magnetic poles, without satisfactory solutions to prevent this issue without increasing size or cost.
The implementation of a winding overhang guide with radial ribs and guide pins that provide radial retention for the winding wires, constraining them against stretching and fatigue, allowing for increased rotational speed.
The radial ribs effectively restrict wire elongation, reducing the risk of fatigue-related breakage and enabling higher rotor rotational speeds without increasing the overall size or manufacturing costs.
Smart Images
Figure 2026505611000001_ABST
Abstract
Description
Summary of the Invention
[0001] The present invention relates to the field of rotating electric machines, and in particular rotors for rotating electric machines, for example as used in electric and hybrid automotive vehicles.
[0002] The present invention particularly relates to winding overhang guides for winding conductive electrical wire around the magnetic poles of a wound rotor.
[0003] A wound rotor generally comprises a rotor shaft designed to rotate about its axis, and a metal core including a lamination stack fixed onto and mounted coaxially relative to the rotor shaft.
[0004] The lamination stack includes a plurality of radially protruding rotor teeth and at least one axial opening, and a conductive wire winding is wound around each rotor tooth. To this end, the rotor includes overhanging guides for the conductive wire around each rotor tooth, located on opposite axial sides of each lamination stack. Each overhanging guide includes a central orifice through which the rotor shaft passes.
[0005] At high rotational speeds, rotors are subjected to harsh operating conditions and are subject to large stresses, particularly in the radial direction, and in particular the rotor windings are subjected to large centrifugal forces as the rotor rotates.
[0006] The winding wire overhang guides are also highly stressed by centrifugal forces as the rotor rotates and must be able to operate under such conditions. To this end, each overhang guide is conventionally rigidly attached to a ring disposed around the periphery of the overhang guide to provide a means for radial retention of the overhang guide (both independent of the body of the rotor).
[0007] The ring is generally annular in shape surrounding the outer periphery of the overhang guide, and its profile has an L-shape including an axially oriented flange abutting the outer periphery of the overhang guide and a radially oriented flange toward the rotor shaft abutting the radial end face of each pole of the overhang guide.
[0008] The ring conventionally includes orifices in its radial flange to allow passage of tie rods and to secure the ring to the overhang guide, and the radial end faces of the poles of the overhang guide and lamination stack include orifices coaxial with the orifices in the ring to allow tie rods to pass axially from the ring through the overhang guide and lamination stack to the opposite side of the rotor.
[0009] Other solutions exist for rigidly attaching the ring to the overhang guide.
[0010] In existing solutions, when passing from one magnetic pole to another adjacent magnetic pole, the winding wires are subjected to centrifugal forces caused by the rotation of the rotor, which causes the wires to stretch and fatigue during acceleration and deceleration of the rotor rotation, which can cause the wires to break.
[0011] To limit damage to the winding wires, it is known to reduce the rotational speed of the rotor, but such a solution is not satisfactory.
[0012] Therefore, there is a need to improve the service life of the winding wire.
[0013] The present invention aims to suppress damage to the winding wire, particularly between two adjacent magnetic poles, without increasing the overall size and manufacturing costs.
[0014] The present invention is directed to a winding overhang guide for winding conductive electrical winding wire around a plurality of rotor teeth of a wound rotor, the winding overhang guide including a cylindrical core with a central orifice for receiving the rotor shaft, and radial guide branches or teeth extending from the cylindrical core, each designed to be positioned facing a corresponding rotor tooth of the rotor.
[0015] The winding overhang guide includes at least one radial rib extending radially toward the central orifice for retaining the winding wire, the rib being each disposed in a notch circumferentially between two guide teeth.
[0016] Each radial rib allows radial retention of the wire between the poles on the winding overhang guide, particularly in the presence of centrifugal forces linked to the rotation of the rotor.
[0017] The radial ribs allow the wires to be constrained from stretching during rotation of the rotor, thus reducing the risk of breakage caused by fatigue.
[0018] Such radial retention by the radial ribs thereby enables the rotational speed of the rotor to be increased.
[0019] The winding overhang guide advantageously further comprises a plurality of guide pins or lugs, each extending axially beyond the cylindrical core, wherein a first guide pin of a guide tooth is connected to a second guide pin of an adjacent guide tooth by a connecting portion extending circumferentially between the two guide teeth, and wherein at least one radial winding wire retaining rib extends radially from each connecting portion, in particular from its underside.
[0020] For example, each connecting portion extends axially beyond the cylindrical core.
[0021] For example, each guide pin extends axially beyond each connecting portion.
[0022] Each radial rib preferably has a parallelepiped shape, the contour of which allows for easy removal of the winding overhang guide from the mold.
[0023] Alternatively, any other shape protruding radially from the connecting portion, whose contour allows for easy removal of the winding overhang guide from the mold, may be used, such as for example a semicircular shape.
[0024] It is equally possible to provide two radial ribs projecting radially from the connecting portion.
[0025] A guide pin on one of the winding overhang guides allows some of the windings to be interconnected to form pairs of magnetic poles.
[0026] The guide teeth are advantageously regularly arranged on the outer periphery of the cylindrical core, the number of guide teeth being equal to the number of rotor teeth.
[0027] The winding overhang guide advantageously includes a guide groove disposed on a lateral edge of each guide tooth for cooperating with the winding wire.
[0028] In a second aspect, the present invention relates to a wound rotor for a rotating electrical machine including a rotor shaft having a rotation axis, wherein two winding overhang guides as described above are disposed at opposite ends of the rotor shaft, and windings are wound around the rotor teeth and the guide teeth of the two winding overhang guides to form rotor poles, respectively.
[0029] The cylindrical core of each winding overhang guide and the rotating shaft of the rotor are advantageously concentric with the axis of rotation, and each guide tooth of each winding overhang guide advantageously faces a rotor tooth in the axial direction.
[0030] The winding overhang guide allows for correct positioning of the wire in the notch during the winding process steps to produce the winding.
[0031] The rotor advantageously further includes a core including lamination packets mounted coaxially relative to the rotor shaft, the lamination packets of the core including alternating rotor teeth and notches regularly distributed circumferentially about the diameter of the core, and at least each radial rib of the winding overhang guide being arranged in a corresponding notch in the circumferential direction.
[0032] For example, the core includes an axial lamination stack extending in a radial plane perpendicular to the axis of the rotor shaft.
[0033] In this radial plane, the laminations of the lamination packet of the core all have the same profile.
[0034] For example, rotor teeth project radially from the rotating shaft towards the outer periphery of the rotor.
[0035] The core is advantageously fitted, for example by press fitting, onto the cylindrical outer surface of the rotating shaft.
[0036] Each rotor tooth may include an arm that extends radially toward the outer periphery of the rotor.
[0037] The free end of each rotor tooth terminates, for example, in protruding return sections on both circumferential sides of the arm, the function of which is to radially hold the electrical excitation winding wound around the radial arm of each rotor tooth against the centrifugal forces to which said winding is subjected during rotation of the rotor.
[0038] Each rotor tooth therefore includes such an excitation winding.
[0039] The winding wires connecting two adjacent rotor teeth are advantageously disposed radially between the corresponding radial rib of each winding overhang guide and the central orifice in the cylindrical core.
[0040] In another aspect, the present invention relates to a rotating electrical machine including a wound rotor as described above.
[0041] Other objects, features and advantages of the present invention will become apparent on reading the following description, given by way of non-limiting example only, and on referring to the accompanying drawings, in which: [Brief explanation of the drawings]
[0042] [Figure 1] 1 is a diagram illustrating a schematic diagram of an example of a wound rotor according to the present invention; [Figure 1A] 2 is a partial view of one end of the wound rotor from FIG. 1, showing very diagrammatically in cross section a wound rotor according to the invention, excluding the windings; FIG. [Figure 2] FIG. 2 is a diagram illustrating a front view of the wound rotor from FIG. 1. [Figure 3] FIG. 3 is a detailed view of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION
[0043] 1, a rotor 10 for a wound electrical machine having a longitudinal axis X-X' includes a rotatable shaft 12 or rotor shaft extending axially through the body of the rotor. The rotor 10 further includes a core 14 containing lamination packets.
[0044] The core 14 is mounted coaxially to the rotor shaft 12 or rotating shaft and comprises an axial lamination stack extending in a radial plane perpendicular to the axis of rotation XX′ of the rotating shaft 12 .
[0045] In this radial plane, all laminations of a lamination packet of the core 14 have the same contour.
[0046] The lamination packet of core 14 includes alternating rotor teeth 16 and notches 18 regularly distributed circumferentially around the diameter of core 14 .
[0047] Rotor teeth 16 project radially from rotatable shaft 12 toward the outer periphery of rotor 10 .
[0048] As shown, and not as a limitation of the present invention, the core 14 includes eight rotor teeth 16 .
[0049] However, the invention is not limited to this type of configuration, but applies to stacked packets containing multiple rotor teeth, preferably at least three rotor teeth.
[0050] The core 14 is fitted, for example by press fitting, onto the cylindrical outer surface of the rotating shaft 12 .
[0051] Each rotor tooth 16 includes an arm 21 that extends radially toward the outer periphery of the rotor 10 .
[0052] The free end 22 of each rotor tooth 16 terminates in protruding return portions on either circumferential side of the arm 21. The function of the protruding return portions 22 of each rotor tooth 16 is to radially retain the conductive excitation winding 30 wound around the radial arm 21 of each rotor tooth 16 against the centrifugal forces to which said winding 30 is subjected during rotation of the rotor 10.
[0053] Each rotor tooth 16 therefore includes such an excitation winding 30 .
[0054] Rotor 10 further includes overhang guides 40 mounted coaxially with rotatable shaft 12 and on axially opposite sides of core 14. Overhang guides 40 allow the conductive wires comprising excitation winding 30 to be guided around corresponding rotor teeth 16.
[0055] Here, the rotor 10 includes two overhang guides 40, only one of which is visible in the figure, with the second overhang guide 40 mounted axially opposite the first overhang guide 40 visible in the figure.
[0056] Each overhang guide 40 takes the form of a disk extending in a radial plane perpendicular to the axis XX′ of the rotating shaft 12 .
[0057] As shown therein, each overhang guide 40 includes a cylindrical core 41 having a central orifice 42 coaxial with the rotating shaft 12 of the rotor 10 .
[0058] Each overhang guide 40 extends from a cylindrical core 41 and includes radial branches or guide teeth 43 (here eight) that are each intended to be positioned facing a corresponding rotor tooth 16 of the rotor 10, in particular a radial arm 21.
[0059] The guide teeth 43 are regularly arranged on the outer periphery of the cylindrical core 41 , and the number of the guide teeth 43 is equal to the number of the rotor teeth 16 .
[0060] Each winding 30 is wound around a rotor tooth 16 and the guide teeth 43 of two winding overhang guides 40 to form, for example, one rotor pole.
[0061] The cylindrical core 41 and the rotating shaft 12 are concentric with the axis XX'.
[0062] Each winding overhang guide 40 is immobilized on the rotating shaft 12 so that each guide tooth 43 faces a rotor tooth 16 in the axial direction.
[0063] The winding overhang guide 40 allows for correct positioning of the wire in the notch 18 during the winding process step to create the winding 30 .
[0064] As can be seen in FIG. 1A, where windings 30 are also not shown, each winding overhang guide 40 includes a guide groove 44 on the lateral edge of each guide tooth 43 for retaining winding wire 30.
[0065] Positioning the winding overhang guide 40 on the rotating shaft 12 allows for repeatable fixation of the start of each winding 30 into the guide groove 44 of each guide tooth 43.
[0066] Each winding overhang guide 40 further includes a guide pin or lug 45 .
[0067] Here, each guide pin 45 extends axially parallel to the axis of rotation X-X′ and axially beyond the cylindrical core 41 of the winding overhang guide 40 .
[0068] A guide pin 45 on one of the winding overhang guides 40 allows the interconnection of some of the windings 30 to form a magnetic pole pair.
[0069] As shown here, each winding overhang guide 40 includes two guide pins 45 a , 45 b associated with each guide tooth 43 .
[0070] A first guide pin 45 a of a guide tooth 43 is connected to a second guide pin 45 b of an adjacent guide tooth 43 by a connecting portion 46 .
[0071] The connecting portion 46 extends circumferentially between two guide teeth 43 .
[0072] Here, each connecting portion 46 extends axially beyond the cylindrical core 41 of the winding overhang guide 40 .
[0073] Here, each guide pin 45 extends axially beyond each connecting portion 46 of the winding overhang guide 40 .
[0074] As shown therein, each connecting portion 46 includes a radial rib 47 that projects axially from the underside of the connecting portion 46 toward the rotating shaft 12 .
[0075] 2, the winding wire 30 connecting two adjacent magnetic poles is disposed radially below the corresponding connection portion 46, in particular the radial rib 47. By "disposed radially below" it is meant that the wire is disposed radially between the corresponding connection portion 46, in particular the radial rib 47, and the central orifice 42 of the cylindrical core 41 of each winding overhang guide 40.
[0076] The radial ribs 47 allow for radial retention of the wires between the poles on the winding overhang guides 40 , particularly in the presence of centrifugal forces linked to rotation of the rotor 10 .
[0077] The winding overhang guide 40 generally includes radial ribs 47 each disposed circumferentially between two rotor teeth 16 in a notch 18 for retaining the winding wire.
[0078] The radial ribs 47 allow for the restriction of elongation of the wires during rotation of the rotor 10, thus reducing the risk of failure due to fatigue. Such radial retention by the radial ribs therefore allows the rotational speed of the rotor 10 to be increased.
[0079] Each overhang guide 40 is monoblock and made from a plastic material with high mechanical strength, typically obtained, for example, by a plastic injection molding process or by molding a thermosetting material.
[0080] Here, each radial rib 47 has a parallelepiped shape, the contour of which allows for easy removal of the winding overhang guide 40 from the mold.
[0081] Alternatively, any other shape projecting radially from the connecting portion 46, such as a semicircular shape, whose contour allows for easy removal of the winding overhang guide 40 from the mold, may be used.
[0082] It is equally possible to provide two radial ribs extending radially from the connecting portion 46 .
Claims
1. 1. A winding overhang guide (40) for winding conductive electrical winding wires (30) around a plurality of rotor teeth (16) of a wound rotor (10), the winding overhang guide (40) comprising: a cylindrical core (41) with a central orifice (42) for accommodating a rotor shaft (12); and radial guide branches or teeth (43) extending from the cylindrical core (41), each radial guide branch or tooth (43) designed to be positioned facing a corresponding rotor tooth (16) of the rotor (10), the winding overhang guide (40) including at least one radial rib (47) for retaining the winding wires, the radial rib extending radially toward the central orifice (42), each radial rib being disposed circumferentially between two guide teeth (43).
2. 2. The winding overhang guide (40) of claim 1, further comprising a plurality of guide pins (45), each extending axially beyond the cylindrical core (41), wherein a first guide pin (45 a) of a guide tooth (43) is connected to a second guide pin (45 b) of an adjacent guide tooth (43) by a connecting portion (46) extending circumferentially between the two guide teeth (43), and at least one radial winding wire retention rib (47) extends radially from each connecting portion (46).
3. The winding overhang guide (40) of claim 2, wherein each connection portion (46) extends axially beyond the cylindrical core (41).
4. A winding overhang guide (40) according to claim 2 or 3, wherein each guide pin (45) extends axially beyond each connecting portion (46).
5. The winding overhang guide (40) of any one of claims 1 to 4, wherein each radial rib (47) has a parallelepiped shape.
6. 6. The winding overhang guide (40) according to claim 1, wherein the guide teeth (43) are regularly arranged on the outer periphery of the cylindrical core (41), and the number of the guide teeth (43) is equal to the number of the rotor teeth (16).
7. 7. The winding overhang guide (40) according to claim 1, comprising a guide groove (44) disposed on a lateral edge of each guide tooth (43) to cooperate with the winding wire (30).
8. A wound rotor (10) for a rotating electric machine including a rotor shaft (12) having a rotation axis (X-X'), wherein two winding overhang guides (40) according to any one of claims 1 to 7 are disposed at opposite ends of the rotor shaft (12), and windings (30) are wound around rotor teeth (16) and guide teeth (43) of the two winding overhang guides (40), respectively, to form rotor poles.
9. 9. The rotor (10) of claim 8, wherein the cylindrical core (41) of each winding overhang guide (40) and the rotating shaft (12) of the rotor (10) are concentric with the rotation axis (X-X'), and each guide tooth (43) of each winding overhang guide (40) faces a rotor tooth (16) in the axial direction.
10. 10. The rotor (10) of claim 8 or 9, further comprising a core (14) including lamination packets mounted coaxially to the rotor shaft (12), the lamination packets of the core (14) including alternating rotor teeth (16) and notches (18) regularly distributed in the circumferential direction of a diameter of the core (14), and at least each radial rib (47) of the winding overhang guide (40) being disposed in a corresponding notch (18) in the circumferential direction.
11. 11. The rotor (10) according to any one of claims 8 to 10, wherein the winding wires (30) connecting two adjacent rotor teeth (16) are disposed radially between the corresponding radial rib (47) of each winding overhang guide (40) and the central orifice (42) in the cylindrical core (41).
12. A rotating electrical machine comprising a wound rotor (10) according to any one of claims 8 to 11.