Connection unit for a three-phase electric motor

Abstract

The present invention relates to a connection unit for a three-phase electric motor with at least six excitation coils, each having an input wire end and an output wire end. The connection unit comprises a non-conductive connection ring with an annular axis and three retaining arrangements, each forming an annular shape and with at least one receiving pocket that is open on at least one side or can be opened on at least one side. The connection unit also includes three connecting wires, each adapted to one of the annular shapes of the three retaining arrangements, which are inserted from the open side or the opening side of the at least one associated receiving pocket. Viewed in the direction of the annular axis, the three connecting wires are arranged on different connection planes and are electrically connectable to the input wires of the excitation coils, each of which is assigned to one of the three phases.

Description

[0001] The present invention relates to a connection unit for a three-phase electric motor with at least six excitation coils, each having an input wire end and an output wire end.

[0002] In electric motors, the excitation coils must be electrically connected. For this purpose, the winding ends at the input and output of the excitation coils must be electrically contacted accordingly. There are numerous different designs for this in the state of the art. For example, the input wire ends and output wire ends are individually led to a contact unit attached to the circumference of the stator arrangement, each assigned to a connection phase. The input wires are alternately connected to the three phases. The interconnection is often carried out using a unit (connection ring), which enables easy contact with an external connector or control unit. This unit thus contains all the necessary conductors and contact elements and is attached to the front of the stator. In a star connection, all output wires are connected to one another for this purpose.Other solutions include, for example, a printed circuit board, assembled units with stamped conductor tracks, overmolded units with conductor tracks, classic cabling, etc.

[0003] In the course of electrification in automotive technology, efforts are being made to find solutions suitable for mass production, not least for cost reasons.

[0004] Based on this, the present invention is based on the object of improving a connection unit mentioned at the outset with regard to its structure and costs in such a way that improved series production is possible.

[0005] This object is achieved according to the invention by a connection unit according to claim 1. For this purpose, the connection unit has a non-conductive connection ring which has a ring axis and three holding arrangements each simulating a ring shape, each with at least one receiving pocket which is open at least on one side or can be opened at least on one side, and three connecting wires which are each adapted to one of the ring shapes of the three holding arrangements and which are each inserted from the open side or the side to be opened of the at least one associated receiving pocket, wherein the three connecting wires are arranged on different connection levels as seen in the direction of the ring axis and can be electrically connected accordingly to the input wires of the excitation coils which are each assigned to one of the three phases.

[0006] Here, the number of excitation coils corresponds to N times the number of phases, where n corresponds to a natural number > 1. The connecting wires are structures produced by a wire drawing process and preferably have a consistent cross-sectional shape and cross-sectional size. Advantageously, no waste is generated during the production of the connecting wire, in contrast to punched conductor tracks and punched conductor rails. The cross-sectional size of the connecting wire is, in line with the number of excitation coils connected to it, preferably larger than the individual cross-sectional size of a corresponding input wire end. This results in a cost-effective and easy-to-manufacture component. The term connecting ring refers to a ring that is essentially completely circumferential, whereby the ring shape can be derived from any regular or irregular polygon shape or a circle.Preferably, it is a polygonal peripheral shape with a number of corners corresponding to the number of excitation coils. The term "ring shape" means at least arranged in a ring shape, whereby gaps may be present; the ring shape can be defined by any regular or irregular polygonal peripheral shape or a circular peripheral shape, preferably a polygonal peripheral shape with a number of corners corresponding to the number of excitation coils. "Non-conductive" means that the connecting ring either has an electrically insulating, non-conductive coating or an electrically insulating, non-conductive sheath, or is made of a non-conductive material, preferably a plastic material.

[0007] Preferably, the connecting ring can have window cutouts on each of the three connection levels that are designed to overlap the respective input wire end in such a way that free lateral access is possible from both the inside and the outside of the connecting ring for attaching a welding tong to weld the respective connecting wire to the respective input wire end. For the purposes of this invention, the term overlappable means that the position of the input wire ends is known and the window cutouts are arranged in such a way that lateral access to the input wire ends and the associated connecting wire is possible. Due to the tong movement of the welding tong, the input wire end and the connecting wire must be contacted and pressed together simultaneously; preferably, the movement and application of force takes place essentially perpendicular to the plane spanned by the corresponding window cutout.This access must be possible at all three connection levels for each of the input wire ends. The connection can therefore be made using very efficient robotics. The connection ring simply needs to be fed into the position dictated by the positions of the input wire ends, and then the welding process can be carried out. Any joining technique that ensures appropriate heat input and can preferably also join dissimilar metals can be used as welding methods. The receiving pockets can also have additional recesses, a lattice structure, etc., as long as it is ensured that the connecting wire is arranged in such a way that it is largely prevented from being displaced or from unintentional deformation. Several receiving pockets can be arranged in a ring shape (gaps may be present between or within the receiving pockets).It is important to hold the respective connecting wire together, which has a ring shape.

[0008] Although the respective connecting wire does not necessarily have to be arranged in the receiving pocket over its entire circumference, for example because of gaps, etc., it is nevertheless advantageous according to a further embodiment if at least one of the holding arrangements has an annular, circumferential receiving pocket into which the associated connecting wire is inserted. This protects the respective connecting wire over its entire circumference and retains its shape. In particular, this also enables very good insulation between the connecting wires, because the connecting wires are preferably inserted without their own insulation layer.

[0009] Advantageously, a first holding arrangement can be arranged behind a second holding arrangement, viewed in the direction of the ring axis, wherein the open side or the side to be opened of the at least one receiving pocket of the first holding arrangement is directed in a direction opposite to the open side or the side to be opened of the at least one receiving pocket of the second holding arrangement. When reference is made to “behind” here, this means the view of the connecting ring in an assembled position with the excitation coils arranged behind it. This also means that the first connecting wire is inserted into the connecting ring opposite to the second connecting wire. Installation can therefore take place simultaneously using a type of pliers movement. It is also possible for the two connecting wires to be identical and aligned coaxially to the ring axis.

[0010] Preferably, each receiving pocket can have a bottom web and two web-shaped side walls arranged at a distance from one another, with a receiving pocket of the first holding arrangement and a receiving pocket of the second holding arrangement having a common bottom web. This simplifies the construction because each receiving pocket essentially represents a receiving rail for at least one section of a connecting wire. Furthermore, the common bottom web can ensure the desired electrical insulation of the two connecting wires from one another.

[0011] Furthermore, it can advantageously be provided that at least the receiving pockets of the first and second holding arrangements have spacers that position the first connecting wire in the first holding arrangement and the second connecting wire in the second holding arrangement at a distance from the base web or webs. Despite the shared base web, the two connecting wires are arranged at a sufficiently large distance from one another and are thus well insulated from one another, even if the base web itself is only thin. Furthermore, the distance from the base web simplifies the disassembly of the respective connecting wire for recycling purposes, because a corresponding removal tool can be better positioned here.

[0012] According to a further embodiment, the holding arrangements in the region of the at least one receiving pocket have a locking lug for locking the connecting wire in the at least one receiving pocket. Inserting the connecting wire into the associated holding arrangement therefore inevitably results in secure fastening or anchoring of the connecting wire in the desired position in the at least one associated receiving pocket. The locking mechanism can be detachable (can be opened without destruction) or non-detachable (can only be opened by destruction). Furthermore, a locking lug can be produced very easily using an injection molding process, provided the connecting ring is manufactured by injection molding.

[0013] In one variant, a third holding arrangement is arranged laterally offset relative to the ring axis and behind the second holding arrangement. This means that the connecting wire arranged in the third holding arrangement is positioned at the shortest distance from the stator of the electric motor. This lateral offset makes it very easy to arrange the third connecting wire in a third plane. Preferably, the third holding arrangement is arranged laterally offset outward, so that the third connecting wire has a larger circumferential shape than at least the second connecting wire.

[0014] Advantageously, the window cutouts in the first holding arrangement can each begin in the area between the corresponding bottom surface of a bottom web of the first holding arrangement and the first connecting wire and can be arranged only in the side walls of the first holding arrangement, wherein the window cutouts in the second holding arrangement each begin in the area between the corresponding bottom surface of a bottom web of the second holding arrangement and the second connecting wire and can be arranged only in the side walls of the second holding arrangement. If the window cutouts are arranged so deep that a tool can be reached under the respective connecting wire, the latter can be very easily removed from the respective holding arrangement, if necessary against a spring force of the at least one locking lug. This simplifies the recycling process.

[0015] Furthermore, it is also possible for the window cutouts in the third holding arrangement to be arranged only in the side walls of the third holding arrangement and to merge into a bottom opening through which the adjacent bottom web is interrupted or cut out. Due to the absence of the bottom web in the area of ​​the window cutout of the third holding arrangement, an extrusion force can be applied in this area, possibly counteracting a spring force of the at least one locking lug, to remove the third connecting wire from the third holding arrangement. This also makes it very easy to recycle.

[0016] The outer side wall of the at least one receiving pocket of the third holding arrangement can be designed higher than the inner side wall of the at least one receiving pocket of the third holding arrangement, wherein the outer side wall in each case has a supplementary recess which is aligned with the adjacent window recesses in the second holding arrangement in such a way that free lateral access is possible from the outside of the connecting ring for attaching welding tongs for welding the second connecting wire to the respective associated input wire end. The third connecting wire, which is located furthest outwards, is thereby received particularly deep in the receiving pocket and is thus protected. The supplementary recess nevertheless enables good access to the second connecting wire and the associated input wire ends. As a result, the distances between the various arrangement levels of the connecting wires can be kept small while providing good protection.

[0017] According to a further embodiment, the inner side wall of the at least one receiving pocket of the second holding arrangement is designed to be higher than the outer side wall of the at least one receiving pocket of the second holding arrangement, and the inner side wall each has a supplementary recess which is aligned with the adjacent window recesses in the third holding arrangement in such a way that free lateral access is possible from the inside of the connecting ring for attaching welding tongs for welding the third connecting wire to the respective associated input wire end. This achieves good internal coverage, whereby the input wire ends are very well protected. The supplementary recess nevertheless enables good access to the third connecting wire and the associated input wire ends.As a result, the distances between the different arrangement levels of the connecting wires can be kept small while providing good protection.

[0018] Preferably, the second holding arrangement and the third holding arrangement can be connected to one another by means of an offset flange running perpendicular to the ring axis, wherein the offset flange has axially parallel openings, each of which is aligned with a window recess in the first holding arrangement and into which an associated input wire end can be inserted for connection to the first connecting wire. This makes it possible to guide the input wire ends for the first connecting wire through the space between the second connecting wire and the third connecting wire. Typically, the input wire end for the first connecting wire protrudes furthest on the end face of the stator laminated core. The axially parallel opening ensures good guidance of this input wire end when sliding on the connecting ring.This design also makes it possible to insert all input wire ends into the connecting ring at the same distance from the ring axis.

[0019] Furthermore, the invention relates to a three-phase electric motor with at least six excitation coils, a stator core, a main shaft, and a connection unit according to one of claims 1 to 12, wherein the excitation coils each have an input wire end and an output wire end, and wherein the input wire ends are connected to the respective associated connection wire in the region of a first end face of the stator core. Such an electric motor can be manufactured very easily and cost-effectively. The automated contacting with the connection unit takes place in the region of an end face of the stator core.

[0020] In one embodiment of the electric motor, it is provided that the output wire ends are electrically connected to one another by means of a ring-shaped, circumferential fourth connecting wire, and that the fourth connecting wire is inserted into a non-conductive, fourth holding arrangement simulating the ring shape and having at least one receiving pocket open on at least one side, from the open side of the at least one receiving pocket of the fourth holding arrangement, such that the fourth connecting wire is held at a parallel distance from the second end face of the stator laminated core, and wherein the fourth holding arrangement has recesses overlapping the respective output wire ends, which are arranged in such a way that free access for applying welding tongs for welding the fourth connecting wire and the respective output wire end is possible. The star connection is therefore carried out on the opposite end face of the stator laminated core.This too can be produced in a simplified and cost-effective manner, with very little space required. This also reduces the wiring effort on the first end face of the stator laminated core by means of the connection unit. Protection can be sought for this embodiment of the electric motor regardless of the specific features of the connection unit, and can therefore be the subject of a divisional application. The key factor here is that the input wire ends are connected in the region of a first end face of the stator laminated core, and that the output wire ends are connected in the region of the second end face of the stator laminated core, as specified in claim 14.

[0021] Advantageously, the excitation coils can be arranged on an insulating body surrounding the stator teeth of the stator core, wherein the insulating body has a ring-shaped fastening device on the outer circumference projecting beyond the first end face of the stator core, on which the connecting ring of the connecting unit sits and is connected thereto, and / or wherein the insulating body forms a fourth holding arrangement projecting beyond the second end face of the stator core and forming a collar. Accordingly, a component already present on the electric motor can be used to fasten the connecting unit. The insulating body is preferably manufactured by injection molding, so that the required fastening device can be molded onto it during production. In the same way, the fourth holding arrangement can also be molded onto the opposite side of the insulating body. This allows manufacturing costs to be reduced.

[0022] It is also possible for receiving pockets of the fourth holding arrangement to have a base web and two web-shaped side walls arranged at a distance from one another, the outer side wall to form a recess and the base web are each interrupted in the transition region by two receiving pockets, wherein on the inner side wall in the transition region between two receiving pockets there is provided an arrangement notch aligned with the recess, into which the protruding end of the respective output wire end is bent, wherein the bent end of the respective output wire end, which preferably rests on the fourth connecting wire, is connected to the fourth connecting ring in the region of the recess and the arrangement notch. The selected connection structure for creating the star connection is constructed in a similar way to that of the connection unit.The fourth connecting wire preferably has the same cross-section as the other three connecting wires. It can preferably have the same circular shape as the third connecting wire, thus reducing the number of different parts in the stator. Due to the recess and the distance of the fourth connecting wire from the second end face of the stator laminated core, the fourth connecting wire can be pressed out of the fourth retaining arrangement, simplifying recycling.

[0023] The invention also relates to the use of a connection unit according to one of claims 1 to 12 for connecting to a stator blank for a three-phase electric motor according to one of claims 13 to 16, wherein the stator blank has at least three excitation coils, a stator laminated core and a main axis, and wherein the excitation coils each have an input wire end and an output wire end.The input wire ends of the excitation coils protrude axially parallel to the main axis on a first end face of the stator laminated core and are arranged at the same distance from the main axis. The connection unit is aligned with its ring axis coaxially to the main axis of the stator blank. The connection unit and the stator blank are then moved coaxially relative to one another until the input wire ends have reached their connection position in alignment with the respective window recesses in the three holding assemblies. Finally, the input wire ends are welded to the respective associated connecting wire using a welding gun. The connection of the stator blank to the connection unit is greatly simplified because the input wire ends can protrude axially parallel and at the same distance from the main axis on the corresponding end face of the stator laminated core.The connection unit can be positioned by simply sliding it coaxially on. The connection is preferably made by means of a latch and a corresponding stop on the insulating body. Finally, a welding tong can perform the welding process required to electrically contact the input wire ends and the respective associated connecting wire through the corresponding window cutouts and any additional cutouts. The entire process can be automated. In the same way, the output wire ends can protrude at the same distance from the main axis on the second end face of the stator laminated core. These are then welded directly to the fourth connecting wire or bent over so that they cover the fourth connecting wire. In the second case, the welding is carried out by means of a tong movement from above and below.

[0024] An exemplary embodiment of the present invention is explained in more detail below with reference to drawings. For simplicity, only the main component, the stator, is shown. The housing and the rotor rotating inside the stator are not shown. Reference may be made to known housing and rotor designs.

[0025] They show: Fig. 1 a perspective front view of a stator with a connection unit according to the invention for an electric motor according to the invention, Fig. 2 a perspective front view of the stator from Fig. 1 without connection unit according to the invention, Fig. 3 a perspective rear view of the stator from Fig. 2, Fig. 4 a perspective view of the stator from Fig. 1 arranged excitation coils, Fig. 5 a perspective view of the stator from Fig. 1 arranged stator core, Fig. 6 a perspective front view of the stator of Fig. 1 arranged insulating body, Fig. 7 a perspective rear view of the insulating body of Fig. 6, Fig. 8 the connection unit Fig. 1 in a full section rotated around the ring axis, Fig. 9 an enlarged view of area IX from Fig. 8, Fig. 10 a perspective front view of the sectioned connection unit from Fig. 8, Fig. 11 a perspective rear view of the cut connection unit from Fig. 10, Fig. 12 a front view of the connecting wires with contact surfaces made of Fig. 1 in a representation rotated around the ring axis, Fig. 13 a top view of the connecting wires from Fig. 12, Fig. 14 is an enlarged cross-sectional view of a fourth retaining arrangement along the line XIV of Fig. 7 cut and with inserted connecting wire, and Fig. 15 is an enlarged front view of a receiving pocket of a fourth holding arrangement.

[0026] The Fig. The stator 1 shown in Figure 1 is intended for a three-phase electric motor (not shown), which additionally has a motor housing and a rotor rotatably arranged inside the stator. The stator 1 has a simplified stator core 2 (see also Fig. 5), twelve simplified excitation coils 3.1, 3.2 and 3.3 (see Fig. 4), an insulating body 4 (see Fig. 6 and Fig. 7) and a connection unit 5 (see also Fig. 8 to 13).

[0027] The excitation coils 3.1, 3.2, and 3.3 are each wound from a varnish-insulated copper wire and have a rounded rectangular coil opening 30. In cross-section, the winding phase of the excitation coils 3.1, 3.2, and 3.3 is approximately trapezoidal, with rounded corners, giving the narrow side facing the stator interior an almost completely rounded shape. The excitation coils 3.1, 3.2, and 3.3 are each assigned to one of the three phases of the electric motor: the excitation coils 3.1 of the first phase, the excitation coils 3.2 of the second phase, and the excitation coils 3.3 of the third phase. In the illustrated embodiment, each of the three phases is assigned four excitation coils 3.1, 3.2, or 3.3. The excitation coils 3.1, 3.2, and 3.3 are arranged in such a way that they alternate circumferentially. Each of the excitation coils 3.1, 3.2, and 3.3 is connected at one end (slightly offset) to an input wire end 6.1, 6.2, or 6.3. The input wire ends 6.1, 6.2, and 6.3 are provided with a winding wire end that protrudes axially parallel to the main axis A of the electric motor. The input wire ends 6.1, 6.2, and 6.3 protrude axially by three different lengths: the input wire ends 6.1 have the greatest protrusion length, the input wire ends 6.2 have a medium protrusion length, and the input wire ends 6.3 have the shortest protrusion length. All input wire ends 6.1, 6.2, and 6.3 are at the same distance from the main axis A and thus on a circular line that runs coaxially around the main axis A.

[0028] At the other end of the excitation coils 3.1, 3.2, and 3.3, an output wire end 7 is provided, approximately in line with the outer edge. In the blanks for the excitation coils 3.1, 3.2, and 3.3, this wire end also initially protrudes exclusively axially parallel to the main axis A and is located at the same distance from the main axis A, thus extending on a circular line that encircles the main axis A coaxially. The output wire ends 7 only acquire their angled shape during the contacting process described below.

[0029] The stator 1 described here, and thus the associated electric motor, are operated in a star connection, i.e., the input wire ends 6.1, 6.2, and 6.3 are each assigned to one of the three control phases, and the output wire ends 7 are interconnected to form the star point in a manner to be described in more detail. However, this also means that the corresponding connections for the star connection take place at different ends of the stator 1.

[0030] The stator core 2 is composed of a plurality of mutually insulated soft iron sheets of identical shape and has protruding stator teeth 8 on its inner side, each with a pole piece 9. Between the stator teeth 8 are receiving channels 10 for receiving the excitation coils 3.1, 3.2, and 3.3 and the insulating body 4. A longitudinal slot 11 is formed between each of the pole pieces 9. The pole pieces 9 are concave on their side facing away from the stator interior, so that together they form a cylindrical receiving space for the rotor (not shown).

[0031] The insulating body 4 is composed of a first ring part 12 and a second ring part 13. This means that the insulating body 4 is divided approximately centrally transversely to its axis. The insulating body 4 has a contour on its inner side that replicates the outer contour of the stator teeth 8 and the pole pieces 9, so that the first ring part 12 can be pushed onto the stator laminated core 2 from the first end face 14, and the second ring part 13 can be pushed onto the stator laminated core 2 from the second end face 15. However, the side of the pole pieces 9 facing the interior of the stator remains free and is not covered by the insulating body 4. The side surfaces of the stator teeth 8 and the pole pieces 9, on the other hand, are completely shielded by the insulating body 4, with the insulating body 4 nestling around them like a shell. In the same way, the receiving channels 10 are also completely lined by the insulating body 4.The insulating body 4 is manufactured from a plastic material by injection molding. The insulating body 4 has a polygonal shape in the area of ​​its ends, with the number of corners of the polygonal shape corresponding to the number of excitation coils 3.1, 3.2, and 3.3. Once the insulating body 4 is pushed onto the stator core 2, whereby the first and second ring parts 12 and 13 can be bonded, the excitation coils 3.1, 3.2, and 3.3 are wound onto the insulating body 4 and the stator teeth 8 covered by it.

[0032] The insulating body 4 further comprises, at its first end, associated with the first end face 14 of the stator core 2, a fastening device 16 extending annularly around the outer circumference. The annular shape of the fastening device 16 is a dodecagon that surrounds an end region of the excitation coils 3.1, 3.2, and 3.3, with one corner of the dodecagon being arranged between each of the excitation coils 3.1, 3.2, and 3.3. The fastening device 16 has an outward offset 17 relative to the contour of the insulating body 4 lining the receiving channels 10. As a result, the fastening device 16 sits on the first end face 14 of the stator laminated core 2 and thus also serves as a stop when inserting the first ring part 12 of the insulating body 4. The ring-shaped fastening device 16 has a height that approximately corresponds to the projection of the excitation coils 3.1, 3.2, 3.3 beyond the first end face 14 of the stator laminated core 2.In each polygon section of the fastening device 16 there is a locking opening 18. The fastening device 16 serves to attach the connection unit 5 in the area of ​​the first end face 14 of the stator laminated core 2.

[0033] The connection unit 5 has an insulating connection ring 19 made of plastic, which has a dodecagonal shape with rounded corners. The connection ring 19 is provided on its underside with a dodecagonal collar 20, which can be pushed onto the fastening device 16 with a substantially precise fit. On the inside, the collar 20 is provided with locking lugs 21, each of which engages from the outside into the locking openings 18 of the fastening device 16. Adjacent to the collar 20, the connection ring 19 is provided with a stepped shoulder 22, which rests on the front side of the fastening device 16 and thus serves as a stop.

[0034] The connecting ring 19 further comprises a first annular channel-shaped holding arrangement 23, a second annular channel-shaped holding arrangement 24, and a third annular channel-shaped holding arrangement 25. A ring-shaped first connecting wire 26 is arranged in the first holding arrangement 23, a ring-shaped second connecting wire 27 is arranged in the second holding arrangement 24, and a ring-shaped third connecting wire 28 is arranged in the third holding arrangement 25. All three connecting wires 26, 27, and 28 have the same cross-sectional shape (in this case, a square shape with rounded corners) and are made of copper or a copper alloy (aluminum or an aluminum alloy is also possible).

[0035] The first holding arrangement 23 has twelve receiving pockets 29 arranged in a row to form a polygon. Each of the receiving pockets 29 of the first holding arrangement 23 has a base web 31 running perpendicular to the ring axis R and two web-shaped side walls 32 and 33 arranged perpendicular thereto and at a distance from one another. The side walls 32 and 33 are beveled at the open end of the receiving pockets 29 to facilitate the insertion of the first connecting wire 26. Spacers 34 are arranged on the base web 31 in the corner regions of the polygonal shape of the first holding arrangement 23, said spacers ensuring that the first connecting wire 26 is arranged at an appropriate distance from the base web 31 within the receiving pocket 29.

[0036] The second holding arrangement 24 also has twelve receiving pockets 35 arranged in a polygonal shape. Each of the receiving pockets 35 of the second holding arrangement 24, together with an associated receiving pocket 29 of the first holding arrangement 23, shares the base web 31. Starting from the base web 31, each of the receiving pockets 35 of the second holding arrangement 24 has two web-shaped side walls 36 and 37 arranged perpendicular to the base web 31 and at a distance from one another, whereby an open side of the receiving pocket 29 points away from the first end face 14 of the stator laminated core 2. The side walls 32 and 36 are arranged one on top of the other and are aligned with one another. The side walls 33 and 37 are arranged one on top of the other and are aligned with one another in the same way.The receiving pockets 29 of the first holding arrangement 23 and the receiving pockets 35 of the second holding arrangement 24 are thus arranged back to back, so that the open sides of the receiving pockets 29 and 35 face in opposite directions. Accordingly, the first holding arrangement 23 is arranged behind the second holding arrangement 24 (in the direction of the ring axis R and viewed from below). Fig. 8)). The side of the base web 31 facing the receiving pocket 35 is also provided with spacers 34 in the corner regions of the polygonal shape of the second holding arrangement 24, which ensure that the second connecting wire 27 is arranged at the appropriate distance from the base web 31 within the receiving pocket 35. The side wall 37 is longer than the side wall 36, whereby the side wall 37, when the connection unit 5 is attached, reaches close to the excitation coils 3.1, 3.2 and 3.3. The side walls 36 and 37 are also each beveled at the open end of the receiving pockets 35 for better insertion of the second connecting wire 27.

[0037] Due to the design of the first holding arrangement 23 and the second holding arrangement 24, the first connecting wire 26 and the second connecting wire 27 can be designed identically. Furthermore, they are located at the same distance from the ring axis R.

[0038] The third holding arrangement 25 also has twelve receiving pockets 38 arranged in a polygonal shape. Each of the receiving pockets 38 of the third holding arrangement 25 has a base web 39 running perpendicular to the ring axis R and two web-shaped side walls 40 and 41 arranged perpendicular thereto and spaced from one another. The collar 20 and the stepped shoulder 22 are arranged on the underside of the base web 39. The side walls 40 and 41 are bevelled at the open end of the receiving pockets 38 for better insertion of the third connecting wire 28. The upper end of the inner side wall 41 of the receiving pocket 38 is connected to the lower end of the outer side wall 36 by means of an offset flange 42 running perpendicular to the ring axis R. Due to this configuration, the third holding arrangement 25 is arranged with respect to the ring axis R and viewed from below ( Fig. 8) is offset laterally outward and arranged behind the second holding arrangement 24. The lateral offset created by the offset flange 42 is selected such that the input wire ends 6.1, 6.2, 6.3 can be arranged in the space between the first or second connecting wire 26, 27 and the third connecting wire 28 in a manner to be described in more detail below. The side wall 40 is longer than the side wall 41, whereby the side wall 40 better shields the third connecting wire 28 from the outside.

[0039] As can be seen in particular from the Fig. 12 and Fig. 13, the connecting wires 26, 27 and 28 are positioned on three planes which are offset along the ring axis R and spanned perpendicular to the ring axis R. The third connecting wire 28 has a larger circumference than the first connecting wire 26 and the second connecting wire 27. The ring shape of the connecting wires 26, 27 and 28 has a gap 43 at one point. This gap 43 is bridged by means of a contact plate 44, 45 and 46 adapted to the respective connecting wire 26, 27 and 28. The first contact plate 44 is welded to the first connecting wire 26, the second contact plate 45 to the second connecting wire 27 and the third contact plate 46 to the third connecting wire 28. The first contact plate 44 and the third contact plate 46 are each welded externally to the associated connecting wire 26 or 28. The second contact plate 45 is welded to the inside of the second connecting wire 27.The three contact plates 44, 45, 46 are arranged radially one behind the other relative to the ring axis R and protrude forward from the connection unit 5 for the attachment of a contact plug (not shown). Each contact plate 44, 45, 46 has a wider, offset foot area 47, 48, and 49 and a narrower, straight plug-in area 50, 51, 52. The contact plug placed on the plug-in areas 50, 51, 52 connects the three connecting wires 26, 27, and 28 to one of the phases.

[0040] The connecting ring 19 has three contact recesses 53, 54 and 55 at the corresponding location. The first contact recess 53 for the first contact plate 44 is located in the side wall 32 of the associated receiving pocket 29. The first contact recess 53 extends from the top side of the base web 31 over the entire height of the side wall 32. The second contact recess 54 for the second contact plate 45 extends from the top edge of the side wall 33 of a receiving pocket 29 into the side wall 37 of a receiving pocket 35. The lower end of the contact recess 54 is essentially at the same height as the lower end of the side wall 36 of the receiving pocket 35. The offset of the second contact plate 45 is selected such that there is no contact with the first connecting wire 26. The third contact recess 55 is arranged in the side wall 40 of a receiving pocket 38 and extends from the upper edge of the side wall 40 to the bottom web 39.The offset and the thickness of the third contact plate 46 are selected such that the third contact plate 46 does not protrude outside the connecting ring 19.

[0041] Every third receiving pocket 29, 35, or 38 of the first, second, and third holding arrangements 23, 24, or 25 is provided with corresponding window cutouts 56, 57, 58. The first window cutouts 56 are located in the side walls 32 and 33 of every third receiving pocket 29 of the first holding arrangement 23. The two window cutouts 56 of a receiving pocket 29 are opposite one another. The height of the window cutouts 56 corresponds to the height of the side walls 32 and 33, i.e., they extend from the upper edge of the side walls 32 and 33 to the top of the base web 31. The window cutout 56 in the side wall 32 is somewhat narrower than the window cutout 56 in the side wall 33.The reason for this is that a locking lug 59 is arranged next to the window recess 56 on the side wall 32, with which the first connecting wire 26 is held in position in the receiving pocket 29 and which can be accessed for recycling purposes using a tool through the opposite window recess 56 in the side wall 33. In total, the first holding arrangement 23 has four such locking lugs 59, each adjacent to the window recess 56 in a side wall 32.

[0042] The second window cutouts 57 are located in the side walls 36 and 37 of every third receiving pocket 35 of the second holding arrangement 24. The two window cutouts 57 are opposite one another. The height of the window cutouts 57 essentially corresponds to the height of the side wall 36, i.e., they extend from the underside of the base web 31 to the lower edge of the side wall 36, so that the offset flange 42 is also interrupted in the area of ​​the window cutout 57 arranged in the side wall 36. In the side wall 37, there is a window cutout 57, which is closed all the way around on all four sides and is wider than the corresponding window cutout 57 in the side wall 36.The reason for this is that next to the window recess 57 in the side wall 36 there is a locking lug 59 with which the second connecting wire 27 is held in position in the receiving pocket 35, and this locking lug 59 can be accessed through the opposite window recess 57 in the side wall 37 by means of a tool for recycling purposes.

[0043] The third window recesses 58 are located in the side walls 40 and 41 of each third receiving pocket 38 of the third holding arrangement 25. The window recesses 58 merge into a bottom opening 60, so that the bottom web 39 and the collar 20 are also recessed in extension of the window recesses 58. The two window recesses 58 are opposite each other. The height of the window recesses 58 extends from the top side of the adjacent bottom web 39 to the underside of the offset flange 42. The window recess 58 in the side wall 40 is narrower than the oppositely arranged window recess 58 in the side wall 41.The reason for this is that next to the window recess 58 in the side wall 40 there is a locking lug 59 with which the third connecting wire 28 is held in position in the receiving pocket 38, and this locking lug 59 can be accessed through the opposite window recess 58 in the side wall 41 by means of a tool for recycling purposes.

[0044] To ensure that the side wall 37 of the second holding arrangement 24 does not partially cover the third window recesses 58 in the radial direction, supplementary recesses 61 are provided in the side wall 37, which are aligned with the third window recess 58 in the side wall 41 and have the same width, so that access to the locking lug 59 is still guaranteed. The height of the supplementary recesses 61 extends from the underside of the side wall 37 ( Fig. 9) up to the height of the underside of the offset flange 42. A total of four additional recesses 61 are provided, evenly distributed.

[0045] To ensure that the side wall 40 of the third holding arrangement 25 does not partially cover the second window recesses 57 in the radial direction, supplementary recesses 62 are provided in the side wall 40, which are aligned with the second window recess 57 in the side wall 36 and have the same width. The height of the supplementary recess 62 extends from the top of the side wall 40 ( Fig. 9) up to the height of the underside of the offset flange 42. A total of four additional recesses 62 are provided, evenly distributed.

[0046] The second window cutouts 57 are offset by 30° around the ring axis R from the first window cutouts 56. The third window cutouts 58 are offset by 30° around the ring axis R from the second window cutouts 57 and by 60° around the ring axis R from the first window cutouts 56. This offset arrangement is repeated four times around the circumference of the connecting ring 19. The first window cutouts 56 are located at the height of the first connection level of the first connecting wire 26. The second window cutouts 57 are located at the height of the second connection level of the second connecting wire 27. The third window cutouts 58 are located at the height of the third connection level of the third connecting wire 28.

[0047] Four axially parallel openings 63 are provided in the offset flange 42, evenly distributed around the circumference. These openings are aligned with the first window recess 56 of the side wall 32, i.e., are each arranged in the center of this first window recess 56. The opening 63 is arranged such that it also partially intersects the side wall 36 and runs in a groove-like manner on its outer side, and is chamfered in the region of the upper side of the base web 31. This configuration makes it possible for the input wire ends 6.1 of the excitation coils 3.1 to also penetrate the connecting ring 19.

[0048] When placing the connection unit 5 on the Fig. 2, care is taken to align the ring axis R and the main axis A and to rotate the connection unit 5 so that the first input wire ends 6.1 are aligned with the openings 63. The connection unit 5 can be placed axially onto the stator blank. The locking lugs 21 engage in the locking openings 18 on the collar 20. The first input wire ends 6.1 extend through the openings 63, partially through the side wall 36 and into the first window recess 56 of the side wall 32 to approximately the level of the upper edge of the first holding arrangement 23. The second input wire ends 6.2 extend directly into the second window recess 57 in the side wall 36 and end slightly above the second connecting wire 27 ( Fig. 9). The third input wire ends 6.3 extend directly into the third window recess 58 in the side wall 41 and end slightly above the third connecting wire 28 ( Fig. 9). As a result, all input wire ends 6.1, 6.2, 6.3 are located at the height of the associated connection level directly next to the respectively assigned connecting wire 26, 27 or 28, without any additional elements being arranged in between. Due to the respectively assigned first, second and third window cutouts 56, 57 and 58 as well as the additional cutouts 61 and 62, the input wire ends 6.1, 6.2, 6.3 and the respectively associated connecting wire 26, 27 or 28 can now be directly accessed through these cutouts using a welding tong. A welding action can therefore be performed that corresponds to a tong movement that is essentially executed transversely to the main axis A. This enables automated and very precise contacting of the input wire ends 6.1, 6.2 and 6.3 with the respectively associated connecting wire 26, 27 or 28.

[0049] The waste-free production of the connecting wires 26, 27, and 28 and their arrangement in a connecting ring 19, which was produced as a tool-free part, ensure cost-effective production. The assembly of the connecting ring 19 with the connecting wires 26, 27, and 28 is also very simple and automated. The selected design with the locked positioning of the connecting wires 26, 27, and 28, as well as the access to the locking lug 59 and the respective undersides of the connecting wires 26, 27, and 28 using a tool, also simplifies the recycling of these valuable raw materials.

[0050] In the following, additional use of the Fig. 14 and Fig. 15 the design of the star connection on the opposite end face of the stator laminated core 2 is explained in more detail.

[0051] A fourth holding arrangement 64 is formed on the second ring part 13 of the insulating body 4 and projects beyond the second end face of the stator laminated core 2 in the form of a collar. The fourth holding arrangement 64 accommodates the polygonal shape of the second ring part 13. Compared to the sections of the second ring part 13 lining the receiving channels 10, the fourth holding arrangement 64 has an offset 65 which serves to sit on the second end face 15 of the stator laminated core 2. The fourth holding arrangement 64 serves to arrange a fourth connecting wire 66. The connecting wire 66 is configured identically to the third connecting wire 28. However, the gap 43 is not present; instead, the two ends of the fourth connecting wire 66 are butt-welded.

[0052] To accommodate the fourth connecting wire 66, the fourth holding arrangement 64 has receiving pockets 67 that are evenly distributed around the circumference and open on one side. The receiving pockets 67 form a type of insertion groove for the fourth connecting wire 66. Recesses 68 are provided between the twelve receiving pockets 67. In these recesses 68, a resilient locking lug 69 and an arranging notch 70 are provided next to one another above the adjacent receiving pockets 67. The arranging notch 70 is aligned with the output wire ends 7 projecting on the second end face 15 of the stator core 2. As shown in Fig.14, the fourth connecting wire 66 is positioned within the receiving pocket 67 by means of the locking lug 69. The receiving pocket 67 has a bottom web 71 and two web-shaped side walls 72 and 73 arranged at a distance from one another. The bottom web 71 is aligned perpendicular to the main axis A. The two side walls 72 and 73 extend perpendicular to the bottom web 71. The bottom web 71 is positioned at a distance from the second end face 15 of the stator laminated core 2, so that the fourth connecting wire 66 is also positioned at a distance above the second end face 15 of the stator laminated core 2. The fourth connecting wire 66 is located approximately at the level of the correspondingly assigned ends of the excitation coils 3.1, 3.2 and 3.3. Overall, the fourth holding arrangement 64 projects only slightly beyond the coil ends (mainly with the molding for the locking lug 69 and the arrangement notch 70.

[0053] When connecting the output wire ends 7 of each of the excitation coils 3.1, 3.2, and 3.3, the end regions are first bent into the respective arrangement notch 70 so that they are angled outward by 90°. This places the angled end regions above the fourth connecting wire 66 and can rest on it. The angled end regions of the output wire ends 7 and the fourth connecting wire 66 can now be welded together using welding tongs. This time, the welding is performed with a welding tong movement that is carried out essentially parallel to the main axis A from above and below. One of the welding jaws moves under the fourth connecting wire 66, the other rests against the angled end region of the corresponding output wire end 7. This welding process can also be automated and carried out very quickly and precisely. List of reference symbols 1 stator 2 stator laminations 3.1 Excitation coil connected to the 1st phase 3.2 Excitation coil connected to the 2nd phase 3.3 Excitation coil connected to the 3rd phase 4 insulating bodies 5 Connection unit 6.1 Input wire end excitation coil 3.1 6.2 Input wire end excitation coil 3.2 6.3 Input wire end excitation coil 3.3 7 Output wire end 8 stator teeth 9 Pole piece 10 recording channels 11 Longitudinal slot 12 first ring part 13 second ring part 14 first front side 15 second front side 16 Fastening device 17 Offset 18 locking opening 19 connecting ring 20 collars 21 Snap-on collar 22 step landing 23 first holding arrangement 24 second holding arrangement 25 third holding arrangement 26 first connecting wire 27 second connecting wire 28 third connecting wire 29 Receiving pocket first holding arrangement 23 30 spool opening 31 floor bridge 32 outer side wall receiving pocket 29 33 inner side wall pocket 29 34 spacers 35 Receiving pocket second holding arrangement 24 36 outer side wall receiving pocket 35 37 inner side wall receiving pocket 35 38 receiving pocket third holding arrangement 25 39 Bottom bar pocket 38 40 outer side wall receiving pocket 38 41 inner side wall pocket 38 42 Offset flange 43 gap 44 first contact plate 45 second contact plate 46 third contact plate 47 first foot area 48 second foot area 49 third foot area 50 first plug-in area 51 second plug-in area 52 third plug-in area 53 first contact recess 54 second contact recess 55 third contact recess 56 first window recess 57 second window recess 58 third window recess 59 Locking lug on the window recess 60 floor opening 61 Additional recess 62 Additional recess 63 Opening 64 fourth holding arrangement 65 offset 66 fourth connecting wire 67 Receiving pocket fourth holding arrangement 64 68 recess 69 Locking lug on the fourth retaining arrangement 70 Arrangement notch 71 Bottom bar pocket 67 72 outer side wall receiving pocket 67 73 inner side wall receiving pocket 67 A main axis R ring axis

Claims

[1] Connection unit (5) for a three-phase electric motor with at least six excitation coils (3.1, 3.2, 3.3), each having an input wire end (6.1, 6.2, 6.3) and an output wire end (7), wherein the connection unit (5) comprises a non-conductive connection ring (19) having a ring axis (R) and three holding arrangements (23, 24, 25) each simulating a ring shape, each having at least one receiving pocket (29, 35, 38) that is open at least on one side or can be opened at least on one side, and three connecting wires (26, 27, 28) each adapted to one of the ring shapes of the three holding arrangements (23, 24, 25), which are each inserted from the open side or the side to be opened of the at least one associated receiving pocket (29, 35, 38), wherein the three connecting wires (26, 27, 28) are arranged on different connection levels as seen in the direction of the ring axis (R) and are connected accordingly to the input wire ends (6.1, 6.2, 6.3) the excitation coils (3.1, 3.2, 3.3), each assigned to one of the three phases, are electrically connectable. [2] Connection unit (5) according to claim 1, characterized by that the connecting ring (19) has, on each of the three connecting levels, window recesses (56, 57, 58) designed to overlap the respective input wire end (6.1, 6.2, 6.3) in such a way that free access is possible both from the inside and from the outside of the connecting ring (19) for attaching a welding gun for welding the respective connecting wire (26, 27, 28) to the respective input wire end (6.1, 6.2, 6.3). [3] Connection unit (5) according to claim 1 or 2, characterized by that at least one of the holding arrangements (23, 24, 25) has an annular circumferential receiving pocket (29, 35, 38) into which the associated connecting wire (26, 27, 28) is received. [4] Connection unit (5) according to one of claims 1-3, characterized bythat a first holding arrangement (23) is arranged behind a second holding arrangement (24) as seen in the direction of the ring axis (R) and the open side or side to be opened of the at least one receiving pocket (29) of the first holding arrangement (23) is directed in an opposite direction to the open side or side to be opened of the at least one receiving pocket (35) of the second holding arrangement (24). [5] Connection unit (5) according to one of claims 1-4, characterized by that each receiving pocket (29, 35, 38) has a bottom web (31, 39) and two web-shaped side walls (32, 33; 36, 37; 40, 41) arranged at a distance from one another, and that a receiving pocket (29) of the first holding arrangement (23) and a receiving pocket (35) of the second holding arrangement (24) have a common bottom web (31). [6] Connection unit (5) according to claim 5, characterized bythat at least the receiving pockets (29, 35) of the first and second holding arrangements (23, 24) have spacers (34) which position the first connecting wire (26) in the first holding arrangement (23) and the second connecting wire (27) in the second holding arrangement (24) at a distance from the base web (31) or the base webs (31). [7] Connection unit (5) according to one of claims 1-6, characterized by that the holding arrangements (23, 24, 25) in the region of the at least one receiving pocket (29, 35, 38) have a locking lug (59) for locking the connecting wire (26, 7 20, 28) in the at least one receiving pocket (29, 35, 38). [8] Connection unit (5) according to one of claims 4-7, characterized by that a third holding arrangement (25) is laterally offset with respect to the ring axis (R) and arranged behind the second holding arrangement (24). [9] Connection unit (5) according to one of claims 4-8, characterized bythat the window recesses (56) in the first holding arrangement (23) each begin in the area between the associated bottom surface of a bottom web (31) of the first holding arrangement (23) and the first connecting wire (26) and are arranged only in the side walls (32, 33) of the first holding arrangement (23), and that the window recesses (57) in the second holding arrangement (24) each begin in the area between the associated bottom surface of a bottom web (31) of the second holding arrangement (24) and the second connecting wire (27) and are arranged only in the side walls (36, 37). [10] Connection unit (5) according to claim 8 or 9, characterized by that the window recesses (38) in the third holding arrangement (25) are arranged only in the side walls (40, 41) of the third holding arrangement (25) and merge into a bottom opening (60) through which the adjacent bottom web (39) is interrupted or recessed. [11] Connection unit (5) according to one of claims 8-10, characterized by that the outer side wall (40) of the at least one receiving pocket (38) of the third holding arrangement (25) is designed to be higher than the inner side wall (41) of the at least one receiving pocket (38) of the third holding arrangement (25) and the outer side wall (40) in each case has a supplementary recess (62) which is aligned with the adjacent window recesses (57) in the second holding arrangement (24) in such a way that free lateral access from the outside of the connecting ring (19) for attaching a welding tong for welding the second connecting wire (27) to the respectively associated input wire end (6.2) is possible. [12] Connection unit (5) according to one of claims 8-11, characterized bythat the inner side wall (37) of the at least one receiving pocket (35) of the second holding arrangement (24) is designed to be higher than the outer side wall (36) of the at least one receiving pocket (35) of the second holding arrangement (24) and the inner side wall (37) in each case has a supplementary recess (61) which is aligned with the adjacent window recesses (58) in the third holding arrangement (25) in such a way that free lateral access from the inside of the connecting ring (19) for attaching a welding tong for welding the third connecting wire (28) to the respectively associated input wire end (6.3) is possible. [13] Connection unit (5) according to one of claims 8-12, characterized bythat the second holding arrangement (24) and the third holding arrangement (25) are connected to one another by means of an offset flange (42) running perpendicular to the ring axis (R), and that the offset flange (42) has axially parallel openings (63) which are each aligned with a window recess (56) in the first holding arrangement (23) and into which an associated input wire end (6.1) can be inserted for connection to the first connecting wire (26). [14] Three-phase electric motor with at least six excitation coils (3.1, 3.2, 3.3), a stator laminated core (2), a main axis (A) and a connection unit (5) according to one of claims 1-13, wherein the excitation coils (3.1, 3.2, 3.3) each have an input wire end (6.1, 6.2, 6.3) and each have an output wire end (7) and wherein the input wire ends (6.1, 6.2, 6.3) are connected to the respectively associated connection wire (26, 27, 28) in the region of a first end face (14) of the stator laminated core (2). [15] Three-phase electric motor in star connection according to claim 14, characterized byin that the output wire ends (7) are electrically connected to one another by means of a ring-shaped, circumferential fourth connecting wire (66), and the fourth connecting wire (66) is inserted into a non-conductive, fourth holding arrangement (64) simulating the ring shape, having at least one receiving pocket (67) that is open at least on one side or can be opened at least on one side, from the open side or the side to be opened of the at least one receiving pocket (67) of the fourth holding arrangement (66), so that the fourth connecting wire (66) is held at a parallel distance from the second end face (15) of the stator laminated core (2), and wherein the fourth holding arrangement (64) has recesses (68) arranged to overlap the respective output wire ends (7) in such a way that free access is possible for attaching a welding tongs for welding the fourth connecting wire (66) and the respective output wire end (7). [16] Three-phase electric motor according to one of claims 14 or 15, characterized by that the excitation coils (3.1, 3.2, 3.3) are arranged on an insulating body (4) surrounding the stator teeth (8) of the stator laminated core (2), and that the insulating body (4) has, in a ring shape on the outer circumference, a fastening device (16) projecting beyond the first end face (14) of the stator laminated core (2), on which the connecting ring (19) of the connecting unit (5) sits, whereby it is connected to it, and / or that the insulating body (4) has a collar projecting beyond the second end face (15) of the stator laminated core (2), which forms the fourth holding arrangement (64). [17] Three-phase electric motor according to claim 15 or 16, characterized byin that the receiving pockets (67) of the fourth holding arrangement (64) have a bottom web (71) and two web-shaped side walls (72, 73) arranged at a distance from one another, in that the outer side wall (72) for forming a recess (68) and the bottom web (71) are each interrupted in the transition region between two receiving pockets (67), and in that on the inner side wall (73) in the transition region between two receiving pockets (67) there is provided an arrangement notch (70) which is aligned with the recess (68) and into which the projecting end of the respective output wire end (7) is bent, wherein the bent end of the respective output wire end (7) resting on the fourth connecting wire (66) is connected to the fourth connecting wire (66) in the region of the recess (68) and the arrangement notch (70). [18] Use of a connection unit (5) according to one of claims 1-13 for connecting to a stator blank for a three-phase electric motor according to one of claims 14-17, wherein the stator blank has at least three excitation coils (3.1, 3.2, 3.3), a stator core (2) and a main axis (A), and wherein the excitation coils (3.1, 3.2, 3.3) each have an input wire end (6.1, 6.2, 6.3) and an output wire end (7), characterized bythat the input wire ends (6.1, 6.2, 6.3) of the excitation coils (3.1, 3.2, 3.3) protrude axially parallel to the main axis (A) on a first end face (14) of the stator laminated core (2) and are arranged at the same distance from the main axis (A), that the connection unit (5) is aligned with its ring axis (R) coaxially to the main axis (A) of the stator blank, that the connection unit (5) and the stator blank are then aligned, that the connection unit (5) and the stator blank are then moved coaxially relative to one another until the input wire ends (6.1, 6.2, 6.3) have reached their connecting position in alignment with the respective associated window recesses (56, 57, 58) in the three holding arrangements (23, 44, 25), and that finally the input wire ends (6.1, 6.2, 6.3) are welded to the respective connecting wire (26, 27, 28) using welding tongs.

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