Electric machine with radial openings for impregnation and method for producing an electric machine

Abstract

The invention relates to an electric machine having a magnetic flux-carrying element (1) and a current-carrying element, wherein the magnetic flux-carrying element (1) has a main body (2) and a plurality of grooves (3) formed in the main body (2), in which grooves (3) a coil (5) forming an electrical conductor (4) is positioned, and portions of the electrical conductor (4) in the grooves (3) are covered by an insulating means (6) and / or the respective groove (3) is closed with a groove closing means (7), wherein the insulating means (6) and / or the groove closing means (7) has a radial opening (8) for impregnating the coil (5). The invention also relates to a method for producing a previously mentioned electric machine, having a magnetic flux-carrying element (1) formed from a laminated core, wherein, in a first step, a coil (5) forming an electrical conductor (4) is positioned in grooves (3) of the magnetic flux-carrying element (1), portions of the electrical conductor (4) being covered by an insulating means (6), in a second step, a groove closing means (7) is positioned in each of the grooves (3), wherein the insulating means (6) and / or the groove closing means (7) has radial openings (8), and, in a third step, the main body (2) is sprinkled with an impregnating resin on its radially inner side at a specific axial position in such a way that the impregnating resin flows into the grooves (3) comprising the insulating means (6) and / or the groove closing means (7) and is distributed both radially and axially in the grooves (3).

Description

[0001] Electrical machine with radial openings for impregnation and method for producing an electrical machine

[0002] The invention relates to an electrical machine with a magnetic flux-carrying element, for example a stator or a rotor, and a current-flow-carrying element, wherein the magnetic flux-carrying element has a base body and a plurality of radially open slots introduced into the base body, in which slots a coil forming an electrical conductor is positioned and the electrical conductor is wound in sections in the slots with an insulating means and / or the respective slot is closed with a slot closure means.

[0003] In principle, it is known that the windings of a stator or rotor coil are impregnated. In the currently used trickle impregnation process, the coil winding ends are dripped with resin, and the resin is distributed under the influence of forces such as gravity, capillary force, and centrifugal force. A particular disadvantage, however, is that the impregnation of the winding ends causes resin to reach areas where undesirable residues remain. These include, for example, the end faces of stators or rotors formed as laminated cores. Furthermore, the overall process time is increased due to the long duration of the flow processes caused by the forces.

[0004] The object of the present invention is to provide an electrical machine in which impregnation can be implemented more effectively.

[0005] This is achieved in a generic electrical machine in that the insulation means and / or the slot closure means each have / have a radial opening for impregnating the coil. The radially open slot can be open radially from the outside or from the inside, based on the design of the stator and rotor, depending on whether the rotor is an internal rotor or external rotor. The magnetic flux-carrying element is preferably formed from a laminated core. Teeth are formed between each two adjacent slots. The radial opening forms a partial region into which an impregnating resin can be flowed to impregnate the coil.

[0006] The radial opening ensures that impregnation can occur from a radial direction. Furthermore, the radial opening provides a flow channel or flow direction to allow the impregnating resin to spread and ensure that the impregnating resin can flow between the windings of the coil formed by the electrical conductors.

[0007] Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

[0008] It is expedient if the radial opening is formed along a longitudinal direction of the groove. The greatest extent of the opening is in the longitudinal direction of the groove. This ensures a flexible design of the radial opening. Preferably, the radial opening can even extend from a first axial end side of the groove to a second axial end side of the groove. Accordingly, a gap between the first axial end side and the second axial end side is formed by the opening. Sections of the slot closure means and / or the insulation means are in contact with two sides opposite in the circumferential direction. The position of the radial opening in the width direction is flexible, preferably in the middle of the groove in the width direction. This ensures an even distribution of the impregnating resin in the groove. The slot closure means and / or insulation means are preferably designed with slots in the longitudinal direction.

[0009] Alternatively, the radial opening can be formed along a width direction of the groove. The greatest extent of the opening is in the width direction of the groove. This ensures a flexible design of the radial opening. Preferably, the radial opening can extend from a first circumferential side to a second circumferential side of the same groove, wherein (in each case) two longitudinally opposite sides of the slot closure means and / or the insulation means are opposite each other. The position of the radial opening in the longitudinal direction is flexible, preferably in the middle of the groove in the longitudinal direction. This ensures a uniform distribution of the impregnating resin in the groove. The slot closure means and / or insulation means are preferably designed with slots in the width direction.

[0010] It is advantageous if the slot closure means has a plurality of closure elements in a groove, and the radial opening is positioned between the closure elements. Preferably, the slot closure means is formed from two slot closure elements that are spaced apart from one another in the longitudinal direction or the width direction of the groove. The radial opening is in the form of a gap, which is formed according to the extension in the longitudinal direction or width direction, between opposite sides of the slot closure elements, so that the slot closure means is divided. Alternatively, however, the slot closure means can also be formed from a plurality of slot closure elements in a groove.

[0011] Furthermore, the insulation means can have multiple sections, and the radial opening can be positioned between the sections. The insulation means is preferably designed in multiple parts, preferably in two parts, with the radial opening positioned between the individual sections in the longitudinal direction or in the width direction. The radial opening is in the form of a gap, which is formed according to the extension in the longitudinal direction or width direction, between opposite sides of the sections, so that the insulation means is divided. Alternatively, however, the insulation means can also be formed from a plurality of sections in a groove.

[0012] It is advisable if the insulation material is insulation paper.

[0013] Furthermore, the radial opening can be a through-hole with a round, square, or oval cross-section. This allows for a particularly flexible opening design, which can be selected depending on the design of the electrical machine. Furthermore, it is advantageous to have multiple openings in the insulation and / or slot closure means, which are preferably distributed and / or extend in the longitudinal or width direction. This can further improve the impregnation process.

[0014] The invention also relates to a method for producing a previously described electrical machine with a magnetic flux-carrying element formed from a laminated core, wherein in a first step an electrical conductor wound as a coil is positioned in slots of the magnetic flux-carrying element, which electrical conductor is wound in sections with an insulating means, in a second step a slot closure means is positioned in each of the slots, wherein the insulating means and / or the slot closure means have radial openings and in a third step the laminated core and the insulating means and / or the slot closure means are sprinkled with an impregnating resin in an axial direction from a radial direction.

[0015] This process ensures that the impregnating resin only reaches the required areas. The impregnating resin flows radially between the coil winding and the slot. Furthermore, by impregnating the areas, direct impregnation is ensured, eliminating the need for flow processes to distribute the impregnating resin in geometrically undefined flow channels. Overall, the impregnating resin is metered directly, allowing the radial openings to be filled directly. Because the resin is only introduced into the areas of the radial openings, areas spaced apart from them, such as both axial end faces / end sides of the magnetic flux-carrying element in the sense of the winding heads, are kept free of impregnating resin.

[0016] Various advantageous embodiments of the invention are explained in more detail below with reference to a drawing with figures.

[0017] Shown are: Fig. 1 a magnetic flux-carrying element in the form of a stator in a perspective view,

[0018] Fig. 2 is a sectional view of the stator according to Fig. 1 with a slot closure means in a second embodiment, and

[0019] Fig. 3 the stator according to Fig. 1 in a sectional view with a dosing position.

[0020] The figures are merely schematic and serve solely to facilitate understanding of the invention. The same elements are provided with the same reference numerals. Features of the individual embodiments can be interchanged and used alternatively / cumulatively.

[0021] Fig. 1 shows an electrical machine according to the invention with a magnetic flux-carrying element 1 and a current-flow-carrying element (not shown here), wherein the magnetic flux-carrying element 1 has a base body 2 and a plurality of radially open slots 3 introduced into the base body 2, in which slots 3 a coil 5 wound as an electrical conductor 4 is positioned and the electrical conductor 4 is wound in sections in the slots 3 with an insulating means 6 (see Fig. 2) and / or the respective slot 3 is closed with a slot closure means 7. It should be emphasized that the insulating means 6 and / or the slot closure means 7 have / have a radial opening 8 for impregnating the coil 5.

[0022] For clarity, an axial direction 9, a radial direction 10, and a circumferential direction 11 are defined. The axial direction 9 describes the extension of the magnetic flux-carrying element 1 along a central axis 12, while the radial direction 10 is aligned vertically to the axial direction 9. The circumferential direction 11 describes a potential direction of rotation of a rotor (not shown here).

[0023] In the present embodiment, the magnetic flux-guiding element 1 is designed as a stator 13. The stator 13 is formed from a plurality of individual laminations stacked in the axial direction 9. The stator 13 has a plurality of slots 3 distributed in the circumferential direction 11 and arranged evenly relative to one another and extending in the axial direction 9. The coil 5 is positioned in the slots 3. The coil 5 is positioned in the slots 3 such that, in the axial direction 9, a first winding head 15 is arranged at a first axial end side 14 (of the slot 3) and a second winding head 17 is arranged at a second axial end side 16 (of the slot 3). These end sides 14, 16 directly form the axial end faces 30, 31 of the base body 2.

[0024] A tooth 18 is formed between each two grooves 3. Each pair of circumferentially opposite teeth 18 of a groove 3 has projections in the form of pole shoes 19 extending in the circumferential direction 11, which pole shoes 19 are opposite each other. A gap is also formed between these pole shoes 19.

[0025] In the present embodiment, the groove closure means 7 is arranged in the grooves 3, between each two teeth 18. The groove closure means 7 has two closure elements 20, 21, namely a first closure element 20 and a second closure element 21. The closure elements 20, 21 are spaced apart from one another in the axial direction 9 along a longitudinal direction 22, which corresponds to the axial direction 9, of the groove 3, so that the radial opening 8 is formed between the two closure elements 20, 21. In the present case, the radial opening extends from a first circumferential side 34 to a second circumferential side of the groove 3.

[0026] Accordingly, the slot closure means 7 is designed in two parts. The two closure elements 20, 21 have a longitudinal gap formed as a radial opening 8. The two closure elements 20, 21 have an identical shape.

[0027] Fig. 2 shows a sectional view of the stator 13 according to Fig. 1 with a slot closure means 7 in a second embodiment. The slot closure means 7 is designed with a radial opening 8, which is formed centrally in the form of a through-hole along a width direction 23, along the circumferential direction 11, of the slot closure means 7. The slot closure means 7 is positioned in the radial direction 10 on a respective underside 24 of the pole shoes 19 and spaced from an upper side 25 of a winding 26 of the coil 5.

[0028] The insulation means 6 rests against side surfaces 27 and a bottom 28 of the slot 3. The insulation means 6, in this case formed as insulating paper, is open on an upper side, which is aligned in the radial direction 10 relative to a lower side 29 of the slot closure means 7, by means of a radial opening 8. These two radial openings enable impregnation of the winding 26 of the coil 5 in the slot 3.

[0029] Fig. 3 shows a dosing position for an impregnating resin for the stator 13. The dosing position is spaced apart in the axial direction 9 from the end faces 30, 31 and the winding heads 15, 17 of the respective axial end faces 14, 16. The direction of impregnation is defined according to an impregnation direction 32, which occurs in the radial direction 10 (toward a radial inner side of the base body 2). An area 33 of impregnation is limited to a partial area in the axial direction 9, forming further partial areas in the axial direction 9 that are not actively impregnated.

[0030] The previous explanations are illustrated in the figures using a specific embodiment of the stator 13. However, these explanations can also apply to a rotor.

[0031] List of reference symbols

[0032] Magnetic flux-carrying element

[0033] Basic body

[0034] Nut

[0035] Electrical conductor

[0036] Sink

[0037] Insulating agents

[0038] Groove sealing agent

[0039] Radial opening

[0040] Axial direction

[0041] Radial direction

[0042] circumferential direction

[0043] central axis

[0044] stator

[0045] First axial end face

[0046] First winding head

[0047] Second axial end face

[0048] Second winding head

[0049] Tooth

[0050] Pole piece

[0051] First slot closure element

[0052] Second slot closure element

[0053] Longitudinal direction

[0054] Latitude direction

[0055] bottom

[0056] Top

[0057] winding

[0058] side surface

[0059] Floor

[0060] Bottom side First end face Second end face Impregnation direction Area first circumferential side second circumferential side

Claims

Patent claims 1. Electrical machine with a magnetic flux-carrying element (1) and a current-flow-carrying element, wherein the magnetic flux-carrying element (1) has a base body (2) and a plurality of slots (3) made in the base body (2), in which slots (3) a coil (5) forming an electrical conductor (4) is positioned, and the electrical conductor (4) is wound in sections in the slots (3) with an insulating means (6) and / or the respective slot (3) is closed with a slot closure means (7), characterized in that the insulating means (6) and / or the slot closure means (7) have / have a radial opening (8) for impregnating the coil (5).

2. Electrical machine according to claim 1, characterized in that the radial opening (8) is formed along a longitudinal direction (22) of the groove (3).

3. Electrical machine according to claim 1 or 2, characterized in that the radial opening (8) extends from a first axial end side (14) to a second axial end side (16) of the same groove (3).

4. Electrical machine according to claim 1, characterized in that the radial opening (8) is formed along a width direction (23) of the groove (3).

5. Electrical machine according to claim 1 or 4, characterized in that the radial opening (8) extends from a first circumferential side (34) to a second circumferential side (35) of the same groove (3).

6. Electrical machine according to one of the preceding claims, characterized in that the slot closure means (7) has a plurality of closure elements (20, 21) and the radial opening (8) is positioned between the closure elements (20, 21).

7. Electrical machine according to one of the preceding claims, characterized in that the insulating means (6) has a plurality of sections and the radial opening (8) is positioned between the sections.

8. Electrical machine according to one of the preceding claims, characterized in that the insulating means (6) is an insulating paper.

9. Electrical machine according to one of claims 1 to 8, characterized in that the opening (8) is a through hole with a round, square or oval cross-section.

10. A method for producing an electrical machine according to one of the preceding claims, with a magnetic flux-carrying element (1) formed from a laminated core, wherein in a first step a coil (5) forming an electrical conductor (4) is positioned in slots (3) of the magnetic flux-carrying element (1), which electrical conductor (4) is partially wound with an insulating means (6), in a second step a slot closure means (7) is positioned in each of the slots (3), wherein the insulating means (6) and / or the slot closure means (7) have radial openings (8), and in a third step the base body (2) is dripped with an impregnating resin at a specific axial position on its radial inner side in such a way that the impregnating resin flows into the slots (3) comprising the insulating means (6) and / or the slot closure means (7) and is distributed both radially and axially in the slots (3).

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