Winding arrangement and method for manufacturing a winding arrangement

Abstract

Winding arrangement in a machine component for a rotary electric machine (1), comprising: - several grooves (11); - a winding (7) wound with a continuous winding conductor (8) in particular, with several coils (12) each passing through two of the slots (11), wherein coil sides of at least one last wound coil (16) received in the slots (11) are exposed towards corresponding slot openings of the slots (11); and - at least one fixing winding (17, 20a, 20b) formed by a section of the winding conductor (8) with at least one fixing turn passing across a coil head (14) of the at least one last wound coil (16) of the winding (7).

Description

Technical field

[0001] The present invention relates to a winding arrangement for an electric machine and to a method for manufacturing such a winding arrangement for an electric machine. State of the art

[0002] It is generally known that a machine component of an electric machine, such as a stator or a rotor, can be wound using various winding techniques. In these techniques, slots in the machine component are filled with winding wire using methods such as flyer winding, needle winding, or coil winding.

[0003] Depending on the geometric design and arrangement of the slots in the machine component and the winding scheme used, there is a risk that a section or turn of the winding wire may detach from the last wound coil or slip out of the slot. This slippage or detachment of the winding wire can occur during the winding process in the manufacture of the electric machine, during subsequent assembly steps, or during operation of the electric machine. If the slipped or displaced section of the winding wire enters the air gap of the electric machine, this can lead to a mechanical blockage.

[0004] German patent application DE 198 26 886 A1 discloses a rotor for an electric motor which has an additional winding around the connecting wires in the area between the commutator and the rotor body. This additional winding has the effect of increasing the stability of the connecting wires, so that vibration fractures cannot occur during operation, especially during so-called vibration tests. However, the wound wires of the rotor or the armature are not separately secured or fixed by this additional winding, so the wire slippage described above can still occur.

[0005] The publication DE 26 20 917 A1 discloses a method and an arrangement for fixing free winding ends of rotor windings by impregnation. Prior to impregnation, one or more absorbent threads or tapes are laid around the entire circumference of the free winding ends, and their ends are guided to so-called drip points.

[0006] DE 10 2009 001 543 A1 discloses a winding arrangement in which at least two winding strands are connected by an irregular winding section, which is twisted at connection points and attached to the winding head by means of resin.

[0007] In other versions of this publication, only the ends of the absorbent threads or tapes are coated with impregnating resin. A variant is also known in which the ends of the absorbent threads or tapes are inserted into the grooves.

[0008] Ultimately, all the aforementioned variants serve to fix the winding wire against mechanical forces occurring during operation using additional means, such as threads or tapes coated with impregnating resin.

[0009] These additional resources increase material costs and represent an additional expense during the assembly of the electric machine.

[0010] It is therefore an object of the present invention to provide a winding arrangement for a machine component of an electric machine and a method for manufacturing such a winding arrangement, wherein it is ensured that no section or turn of the winding wire comes out of the slots of the machine components. Disclosure of the invention

[0011] This problem is solved by the winding arrangement for an electrical machine according to claim 1 as well as by the machine component, the electrical machine and the method for manufacturing a machine component according to the dependent claims.

[0012] Further details are specified in the dependent claims.

[0013] According to a first aspect, a winding arrangement is provided in a machine component for a rotary electric machine, comprising: - several grooves; - a winding with a continuous winding conductor, in particular with several coils each passing through two of the slots, wherein coil sides received in the slots of at least one last wound coil are exposed towards corresponding slot openings of the slots; and - at least one fixing winding formed by a section of the winding conductor with at least one fixing turn, which runs transversely over a coil head of the at least one last wound coil of the winding.

[0014] One idea behind the winding arrangement described above is to provide a winding scheme that includes one or more fixing turns. In this way, one or more fixing turns can be placed over the coil head of the last wound coil using a section, particularly an end section, thereby securing the turns of the last wound coil. This makes it possible to fix the entire winding without the use of additional means.

[0015] The fixing winding can be provided as part of the entire winding during winding according to the specified winding scheme, so that the production of one or more fixing turns follows directly after the winding of the winding.

[0016] Furthermore, a winding step of the at least one last wound coil can be at least two.

[0017] In particular, the fixing turn can have a different, and especially a larger, winding pitch than the at least one last wound coil. This provides a way to ensure that the at least one fixing turn runs at an angle over the last wound coil.

[0018] According to one embodiment, the fixing winding can pass through grooves that are different from the grooves of the at least one coil wound last.

[0019] It may be provided that the at least one fixing turn runs through two grooves in such a way that the at least one fixing turn runs transversely over the coil heads of at least two coils wound most recently.

[0020] According to one embodiment, the at least one fixing turn can cross the winding head of the at least one last wound coil at an angle of between 10° and 90°, preferably between 20° and 90°, more preferably between 40° and 90°, and particularly between 60° and 90°, with respect to the direction of the winding conductor. Thus, the winding conductor can be fixed particularly reliably by the fixing turn.

[0021] It can be provided that each of the fixing turns is guided through the same slots, with the number of fixing turns being between 1 and 5. In particular, if more than one fixing turn is provided through the same slots, more holding force can be exerted on the coil head of the last wound coil, thus enabling improved fixing of the winding.

[0022] Furthermore, the at least one fixing turn on a rotor shaft, on which the machine component is arranged, can be deflected, in particular at an angle between 5° and 140°, preferably between 20° and 120°, preferably between 30° and 90°, and more preferably between 35° and 60°. By changing the direction of the fixing turn, a further area of ​​the machine component can be reached in which a coil wound last is arranged, thus enabling particularly good fixing.

[0023] In particular, several intersecting fixing turns may be provided.

[0024] According to another aspect, a machine component of an electric machine is provided with the winding arrangement described above.

[0025] Furthermore, the machine component can be designed as a rotor of the electric machine, wherein a commutator is provided for contacting the coils of the winding, so that one or more of the coils are alternately energized when the rotor rotates, the idling winding being connected to commutator terminals in such a way that no current flows through a commutator terminal in the idling winding in any rotor position. In other words, the commutator terminals of the commutator are used only to fix the ends of the idling winding, and the arrangement of commutator segments and sliding contacts ensures that the idling winding cannot be energized at any time.

[0026] According to another aspect, an electric machine with the above machine component is provided.

[0027] According to another aspect, a method for manufacturing a winding arrangement for a machine component of a rotary electric machine is provided, comprising: - Winding several slots of the machine component with a winding conductor to obtain a winding with several coils each passing through two of the slots, wherein coil sides received in the slots of at least one last wound coil are exposed towards corresponding slot openings of the slots; and - Forming a fixing winding with at least one fixing turn from at least one section of the winding conductor, wherein the at least one fixing turn runs transversely over a coil head of the at least one last wound coil of the winding. Brief description of the drawings

[0028] The embodiments are explained in more detail below with reference to the accompanying drawings. These show: Fig. 1 a schematic representation of a rotary brush-commutated electric machine; Fig. 2 a top view of the underside of a rotor of an electric machine with a single fixed winding; and Fig. 3 A top view of the underside of a rotor of an electric machine with two fixing windings. Description of embodiments

[0029] Fig. Figure 1 shows a rotary electric machine 1 comprising a stator 2 with pole shoes (not shown). The stator 2 defines a circular cylindrical inner recess 3. A rotor 10 with a winding is rotatably arranged around a rotor shaft 9 in the inner recess 3 of the stator 2.

[0030] The current supply for the winding of the rotor 10 is provided via a segmented commutator 4 and sliding contacts 5, usually in the form of carbon brushes.

[0031] In general, both the stator 2 and the rotor 10 can be wound with a winding and represent machine components of the electric machine 1.

[0032] The winding 7 of the rotor 10 is implemented using a winding conductor 8, which extends from a commutator terminal 6 of the commutator 4 to the rotor 10 and forms one or more coils of the winding 7 there. The winding conductor 8 then returns to another commutator terminal 6 of the commutator 4. This connection scheme for the coils of the winding 7 can be implemented multiple times with a continuous winding conductor 8 or with separate winding conductors.

[0033] The winding conductor 8 or the winding wire can be made of an electrically conductive metal, for example copper or aluminium, and be covered by an insulating varnish or other insulation to prevent electrical short circuits at touching sections of the winding conductor 8.

[0034] The Fig. Figure 2 shows a top view of an end face of a rotor 10 of the electric machine 1 of the Fig. 1. The rotor 10 has a rotor body with radially extending slots 11 (12 slots in the present embodiment) spaced apart in the circumferential direction U. Coil faces of coils 12 of the winding 7 are located in the slots 11.

[0035] The coils 12 are wound according to a conventional winding scheme and each has winding pitches greater than 1. The winding pitch determines the distance between the slots 11 through which the coil sides of the respective coil 12 are guided, specified in the number of slots 11. The coils 12 can, for example, be wound with a winding pitch of 1:4 as shown, and thus have a slot spacing of 3.

[0036] The coils 12, with their respective coil heads 14, form a winding head 15 at the end faces of the rotor 10. When winding the rotor 10, the coils 12 are wound successively into the slots 11 of the rotor 10. This results in the coil heads 14 being arranged one above the other at the end faces of the rotor 10. Consequently, the coil heads 14 of the first wound coils 12 are covered by the coil heads 14 of subsequently wound coils 12.

[0037] Only the coil heads 14 of the last wound coils 16 are located at the top of the winding head. The windings of these last wound coils 16 are therefore not secured by the coil heads 14 of further coils 12, and individual windings of the last wound coils 16 can come out of the relevant slots 11, leading to damage or failure of the electric machine 1.

[0038] To secure the outer windings of the last wound coils 16 against slippage or displacement, at least one fixing winding 17 is provided, which is preferably wound in the same winding process, runs transversely over one or both (axially opposite) coil heads 14 of the last wound coils 16 and thus holds them in their desired arrangement. The fixing winding 17 can have one or more turns through two or more than two slots.

[0039] In order to ensure that the at least one fixing winding 17 runs transversely over the at least one coil head 14 of the last wound coil 16, a larger winding step (with a slot spacing of 5 in the illustrated embodiment) is required for this fixing winding 17. Fig. 2) provided as the winding step of the last wound coil 16. This allows the fixing winding 17 to extend over a segment of the winding head and thus ensure the fixing of the free, i.e., uncovered, coil heads 14.

[0040] The locking winding 17 can be arranged in a substantially electrically neutral position between two external connections, such as the commutator connections 6, so that no deterioration of performance parameters can occur during operation of the electric machine 1 due to the provision of at least one locking winding 17. In particular, the locking winding 17 can be electrically connected to the commutator 4 in such a way that it is always de-energized, i.e., no two connections of the locking winding are ever energized in any rotor position. In other words, the commutator connections 6 of the commutator 4 are used solely to lock the ends of the locking winding 17, and the design and arrangement of commutator segments and sliding contacts ensure that the locking winding 17 is never energized.

[0041] Alternatively, the at least one fixing winding 17 can be wound immediately after the last wound coil 16 without contacting a commutator terminal 6, so that an electrical series connection of the last wound coil 16 and the at least one fixing winding 17 is achieved.

[0042] In general, it is advantageous for the winding pitch of the at least one fixing winding 17 to be larger than the winding pitch of the last wound coils 16 of the rotor 10. In particular, it can be provided that the difference in the slot spacing with respect to the winding pitch is at least 2, preferably at least 3. In other words, the at least one fixing winding 17 can cross the winding head of the at least one last wound coil 16 with respect to the direction of the winding conductor 8 at an angle of between 10° and 90°, preferably between 20° and 90°, more preferably between 40° and 90°, and particularly between 60° and 90°.

[0043] Depending on the selected winding step, the at least one fixing winding 17 can be deflected at the rotor shaft 9 or, provided suitable insulation is used, at the commutator 4. This deflection allows for greater design flexibility for the at least one fixing winding 17. For example, the deflected fixing winding 17 can run through slots 11 located between the slots 11 through which the coil faces of the last wound coils 16 pass. An example of the position of a deflected fixing winding 17a is shown in Fig. 2 shown with dashed lines. The deflection can be carried out in particular at an angle between 5° and 140°, preferably between 20° and 120°, preferably between 30° and 90°, and more preferably between 35° and 60°.

[0044] The at least one fixing winding 17, which can also be regarded as a final part of the entire winding wound by the winding scheme, is formed from an end section of the winding conductor 8, so that the at least one fixing winding 17 can be wound directly during the winding process, thus no further manufacturing steps are necessary and the rotor 10 does not have to be removed from the winding tool between winding the winding 7 and winding the at least one fixing winding 17.

[0045] The Fig. Figure 3 shows a top view of an end face of another rotor 10 of an electric machine, which is essentially comparable to the rotor of the Fig.2. The embodiment shown there has fixing windings 20a, 20b that run through a first pair of slots 11a and a second pair of slots 11b. One slot 11 of each slot pair 11a, 11b is adjacent to each other. As a result, a section of the respective fixing winding 20a, 20b is deflected at the rotor shaft 9.

[0046] The sections of the fixing winding 20a, 20b cross over between the rotor shaft 9 and the respective slot 11 of the slot pairs 11a, 11b. The fixing windings 20a, 20b running through the two slot pairs 11a, 11b form the shape of a wire loop. Alternatively, the fixing windings 20a, 20b can also be guided through the slots 11 of the respective slot pairs 11a, 11b without deflection.

Claims

[1] Winding arrangement in a machine component for a rotary electric machine (1), comprising: - several grooves (11); - a winding (7) wound with a continuous winding conductor (8) in particular, with several coils (12) each passing through two of the slots (11), wherein coil sides of at least one last wound coil (16) received in the slots (11) are exposed towards corresponding slot openings of the slots (11); and - at least one fixing winding (17, 20a, 20b) formed by a section of the winding conductor (8) with at least one fixing turn passing across a coil head (14) of the at least one last wound coil (16) of the winding (7). [2] Winding arrangement according to claim 1, wherein a winding step of the at least one last wound coil (16) comprises at least two. [3] Winding arrangement according to claim 1 or 2, wherein the fixing winding (17, 20a, 20b) has a winding step that differs from the at least one coil (16) wound last, in particular a larger one. [4] Winding arrangement according to one of claims 1 to 3, wherein the fixing winding (17, 20a, 20b) passes through slots (11) which are different from the slots (11) of the at least one coil (16) wound last. [5] Winding arrangement according to one of claims 1 to 4, wherein the at least one fixing winding (17, 20a, 20b) passes through two slots (11) such that the at least one fixing winding (17, 20a, 20b) passes transversely over coil heads (14) of at least two coils (16) wound last. [6] Winding arrangement according to one of claims 1 to 5, wherein the at least one fixing winding (17, 20a, 20b) crosses the winding head of the at least one last wound coil (16) with respect to the direction of the winding conductor (8) at an angle of between 10° and 90°, preferably between 20° and 90°, more preferably between 40° and 90°, and in particular between 60° and 90°. [7] Winding arrangement according to one of the preceding claims, wherein each of a number of the fixing windings (17, 20a, 20b) are guided through the same slots (11), wherein the number of fixing windings (17, 20a, 20b) is between 1 and 5. [8] Winding arrangement for an electric motor according to one of the preceding claims, wherein the at least one fixing winding (20a, 20b) is deflected on a rotor shaft (9) on which the machine component is arranged, in particular with an angle between 5° and 140°, preferably between 20° and 120°, preferably between 30° and 90°, more preferably between 35° and 60°. [9] Winding arrangement for an electric motor according to one of the preceding claims, wherein several fixing windings (17, 20a, 20b) are provided which cross each other. [10] Machine component of an electric machine (1) with a winding arrangement according to any one of claims 1 to 9. [11] Machine component according to claim 10, which is designed as a rotor of the electric machine (1), wherein a commutator (4) is provided for contacting the coils (12) of the winding (7), so that one or more of the coils (12) are alternately energized when the rotor is rotated, wherein the fixing winding is connected to commutator terminals (6) such that no current flows through a commutator terminal in the fixing winding (17, 20a, 20b) in any rotor position. [12] Electric machine (1) comprising a machine component according to claim 10 or 11. [13] Method for manufacturing a winding arrangement for a machine component of a rotary electric machine (1), comprising: - Winding several slots (11) of the machine component with a winding conductor (8) to obtain a winding (7) with several coils (12) each passing through two of the slots (11), wherein coil sides received in the slots (11) of at least one last wound coil (16) are exposed towards corresponding slot openings of the slots (11); and - Forming a fixing winding (17, 20a, 20b) with at least one fixing turn from at least one section of the winding conductor (8), wherein the at least one fixing turn runs transversely over a coil head (14) of the at least one last wound coil (16) of the winding (7).

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