DE102022005023A1 - Method for producing a line segment for a winding and a stator for an electric machine with a hybrid winding design - Google Patents

Abstract

The production of a line segment for a winding of an electrical machine requires that a strand made of individually insulated and twisted stranded wires is formed into a strand curvature in a central area. The strand is pressed into a rod conductor shape in a second area and in a third area and both end areas of the longitudinal extension of the shaped strand are each pressed with one end of a respective flat wire and brought into a metallically coherent connection. To produce a stator 2 for an electrical machine, a laminated core 4 equipped with grooves and a large number of line segments are required. The cable segments have a shaped strand and two flat wires. The line segments inserted into the grooves in the longitudinal direction of the laminated core are interlaced, welded in pairs to their flat wires and a winding head formed with them is compacted. A drive train for a motor vehicle has an electric machine with a stator 2 produced according to the invention and a torque transmission device.

Description

The present invention deals with a method for producing a line segment for a winding of an electrical machine, the line segment each having two rod conductors which are designed as arms of a shaped strand.

A line segment for a winding is produced starting from several individually insulated, twisted stranded wires.

According to a further aspect of the invention, a method is used to produce a stator for an electrical machine, which has a laminated core or a winding core and a plurality of line segments. The line segments are inserted into the grooves of the laminated core in the longitudinal direction of the laminated core.

The present invention also deals with a drive train for a motor vehicle with an electric machine for driving the motor vehicle, which comprises a correspondingly manufactured stator or correspondingly manufactured line segments.

In other words, the present invention deals with a method for producing a line segment according to the preamble of claim 1, a method for producing a stator according to the preamble of claim 14 and a drive train for a motor vehicle according to the preamble of claim 15.

Technical area

An electric machine for generating torque for a vehicle drive is usually constructed as an arrangement of a rotor and an outer stator, between which there is an air gap. To simplify production, “windings” are not produced by winding individual wires into coils, but rather the coils are formed from several wire elements that are assembled from so-called field coil segments. The coils are used, for example in the DE 10 2012 212 870 B4 (Owner: GM Global Technology Operations LLC; publication date of patent grant: October 14, 2021) which generates the fields for driving the rotor. The stator is therefore a circular device which has a plurality of radially aligned slots with coil windings therein and which is arranged concentrically to an axis of rotation of the rotor. As a coil arrangement z. B. a stator with three phases and three poles have nine pairs of opposing field coils, each of which can be realized with wire elements of different sizes. The stator is used to generate a dynamic magnetic field to operate an electrical machine. For the rotors, both arrangements that have field coil segments and arrangements that are equipped with circumferentially distributed permanent magnets are considered application-specifically.

The formation of stator windings using conductor wires with a covering insulation layer, which are inserted into the stator slots, is possible, for example. B. from the DE 10 2011 000 172 A1 (Applicant: Denso Corporation; disclosure date: September 22, 2011). The windings are formed using U-shaped conductor wire segments that should have a rectangular cross section. Two sections of these segments are arranged in grooves. The conductor wires should be welded together at the overlapping end sections of the segments, which are bent radially outwards.

The electric machines can be used in various engine-gearbox arrangements in motor vehicles. Some examples of such arrangements are in the patent application DE 10 2021 123 019 A1 (Applicant: hofer powertrain innovation GmbH; disclosure date: March 10, 2022). Accordingly, a drive train can also include two electric machines, two inverters and two transmissions, each of which can be accommodated in partial housings. Such an arrangement in an overall housing is also referred to as a drive block.

State of the art

According to the DE 10 2016 123 067 A1 (Applicant: Porsche AG; disclosure date: May 30, 2018) a stator with windings should be formed from rod segments, with four rod segments arranged in each slot. A first group of rod segments connected in series should have a smaller cross section than a second group of rod segments connected in series.

For interconnecting coils, you can do so according to the DE 10 2007 021 321 A1 (Applicant: Siemens AG; disclosure date: November 13, 2008) so-called busbars are used. In the case of a stator with several coils, the coils should be connected to one another on one side of the stator. The ends of the coils should be crimped or welded to ends of busbars. The authors would like to do this DE 10 2007 021 321 A1 improve automated production. The busbars should preferably be punched out of sheet metal. The busbars should have insulation in their middle area have, which can be designed as a sprayed covering. Stranded cables or a solid copper wire can also be used as busbars. Busbars can be curved and lie next to each other in a radial direction.

The DE 11 2019 006 919 T5 (Applicant: Mitsubishi Electronic Corporation; publication date of the German translation: November 11, 2021) and the US 9,419,491 B2 (Owner: Hitachi Metals Ltd.; publication date: August 16, 2016) deal, among other things, with connections for the stator.

According to the DE 10 2014 214 066 A1 (Applicant: Volkswagen Aktiengesellschaft; Disclosure date: January 21, 2016) After the contacting has been completed, the connecting conductors of a head end of the stator should be cast in a casting frame with an insulating material, such as a casting resin, in such a way that only external connections of the connecting conductors lead out.

From the EP 3 512 075 B1 (Owner: Toyota Jidosha Kabushiki Kaisha; patent publication date: October 13, 2021) shows a stator structure in which the coil turns are composed of U-shaped or chevron-shaped segments and should be designed with a substantially rectangular cross section. Two segments should be coupled together with a connector. It is suggested to make the connection by inserting into fits and crimping. This should make welding unnecessary. The connector may be covered with an insulating film on its outer surfaces. Furthermore, according to one embodiment, the body of the connector may be tubular with an elastic or fluid conductor inside. This is intended to enable flexibility in an axial direction. Flexible wires, referred to as “flexible round wire”, are considered as coil material.

The US 6,353,198 B1 (Owner: General Electric Company; publication date: March 5, 2002) is concerned with welding bundles of flat wires for a stator winding using a U-shaped bridge into which the ends of the bundles are inserted.

Other rod conductor arrangements for stators are e.g. B. in the WO 2020/092 570 A1 (Applicant: North Carolina State University; publication date: May 7, 2020) as well as in the DE 10 2020 130 647 A1 (Applicant: Grob GmbH; disclosure date: January 7, 2021). According to the DE 10 2020 130 647 A1 Rod conductors should be formed from individual wire segments because strands would have proven to be disadvantageous in the production of the stator.

Nevertheless, some developers do not consider these supposed disadvantages to be an exclusion criterion for the use of strands in the construction of a stator.

In the US 2012/0 212 088 A1 (Applicant: Innovative Energy, Inc.; publication date: August 23, 2012) rod conductors are described in the form of strands, which should extend in the longitudinal direction of the rotation axis of the stator. Connectors should be welded to both ends of the strands. The connectors should extend as arcs over slightly more than 90° of the curve of the stator and be arranged in different levels.

A winding cable for a stator, which consists of a bundle of nine individual wires, is in the DE 10 2004 050 824 A1 (Applicant: Kabushiki Kaisha Toyota Jidoshokki; disclosure date: May 25, 2005). Depending on a shape of the slot of the stator, the wires can be arranged in a square or trapezoidal manner. An insulating coating on the cable eliminates the need to insert insulation paper into each groove. The cable should be bent at predetermined intervals to form a wave shape. Different cables in a coil head between two different slots should be connected by soldering. It is also proposed to combine groups of conductor wires into a coil. However, it is questionable whether several individual wires run next to each other can accurately be described as one strand.

Strands can, as shown in the WO 2015/ 162 586 A2 (Applicant: Brusa Elektronik AG; publication date: October 29, 2015) achieves a shape that is stable against twisting when bending by mechanically connecting the individual wires to one another along their longitudinal extent. In addition, the ends of the strand can be enclosed by sleeves. The cross sections of a straight shaped strand in the longitudinal direction should be congruent over its entire length. According to an exemplary embodiment in 2 is shown, a cross-sectional shape of a shaped strand should correspond to a trapezoidal shape of a stator slot. In a rolling mill, a strand with a round cross-section should be able to be formed into the desired rectangular or trapezoidal shape. In order to facilitate the insertion of one end of the shaped strand into the stator slot, in the WO 2015/ 162 586 A2 proposed to form tapered ends on the shaped strands. After insertion, a bending process can be carried out on the shaped strand. The ends of the shaped strands can also be made according to the EP 3 051 669 B1 (Owner: Brusa Elektronik AG; publication date: August 22, 2018) must be covered with sleeves.

A method for converting the coil windings from a round strand cross-section into a trapezoidal shape is given in the EP 2 991 199 A1 (Applicant: Mitsubishi Electric Corporation; publication date: March 2, 2016). Here, several strands arranged one above the other, which have a round cross-section, are to be pressed into a conically converging press mold using a stamp. The conductors are then removed from the mold again.

A stator according to the DE 10 2018 131 965 A1 (Applicant: ThyssenKrupp AG; disclosure date: June 18, 2020) has a large number of rod conductors and a large number of connection bars. The rod ladders can be designed as so-called “hairpins” or I-shaped (so-called “I-pins”). Compressed and twisted wire strands can also be used as rod conductors. The bar conductors are arranged in bar conductor groups and the connection of the bar conductors should take place via interconnection web groups, which should be arranged in interconnection levels on both sides of the stator. In the DE 10 2018 131 965 A1 It is also proposed that the height and width of the interconnection bars should differ by a factor of the order of magnitude 1.5. In further disclosure documents from the same applicant, e.g. B. in the DE 10 2017 125 887 A1 (Disclosure date: May 9, 2019), in which DE 10 2018 208 407 A1 (Disclosure date: November 28, 2019) as well as in the DE 10 2018 131 960 A1 (Disclosure date: June 18, 2020), methods and devices for producing stranded wires and electrical machines or their stators are described. There should also be special sections at the head ends of the shaped strands - according to the DE 10 2018 218 732 A1 (Disclosure date: April 30, 2020) can take on the task of heat exchanger sections.

In the WO 2021/250 259 A1 (Applicant: Jaguar Land Rover Ltd.; publication date: December 16, 2021) a permanent magnet synchronous motor is described, the rotor of which should have eight rotor poles. A cylindrical stator, which has grooves extending in the radial direction, is used to accommodate windings, the conductors of the windings, e.g. B. pressed in a rectangular shape, in the grooves should be arranged radially next to each other. A combination of stranded wires and single core wires as well as a combination of axial and radial insertion into such a slot are considered as advantageous stator structures. The coil wire should be formed from a shaped strand, which may have a U-shape, also known as a “hairpin”. The segments can be connected to one another by welding or crimping. In each slot, several main and several secondary conductors should be arranged, which differ in the radial direction due to their dimensions and which are connected to different coils, also referred to as a “dual winding configuration”. These coils can be connected to one or two inverters in various configurations for motor operation.

The aforementioned publications are deemed to be fully incorporated into the present description of the invention with their naming. This is intended to avoid having to discuss again and again generally known relationships between winding cores or laminated cores and windings for the generation of magnetic fields for driving a rotor using a stator and the transmission of torque using a gear device, but rather the terms such as “core”, “Layered core”, “rotor” and “drive torque” should be viewed as also defined for the present invention by reference to the publications.

There are also other publications in the property rights literature that deal with stator windings.

The US 2021/0 006 115 A1 (Applicant: GM Global Technology Operations LLC; Publication date: January 7, 2021) would like to design so-called “hairpin”-like conductors in such a way that the portion of the line that is due to the “skin effect” that occurs with alternating currents is approximately 63% of that to be conducted Alternating current flows through, has a greater depth than the thickness of the individual strands of the conductor. The strands should therefore be made from thinner wires compared to the section of the conductor to which the most line current is allocated due to the “skin effect”. Several embodiments of a conductor with thicker and thinner strands are shown in sectional views at the end of the figure illustration. The shaped strand is still only partially supplied with current, because the “skin effect” allows the current to continue to flow primarily on the outside of the shaped strand.

The DE 10 2005 025 217 A1 (Applicant: Denso Corp.; Disclosure date: December 22, 2005) deals with the topic of “ohmic resistance of a stator winding” and would like to reduce the resistance by arranging differently designed U-conductor segments in a stator, which together form parts of the windings of the stator. The U-conductor segments are designed like a bow. In this way they are Lengths of the bridging sections from first conductor segments to second conductor segments can be shortened. In other words, such a motor requires a whole series of different U-conductor segments, so that production advantages resulting from a high number of identical parts are unlikely to be achieved.

The DE 603 06 850 T2 (Owner: Denso Corp.; publication date: September 6, 2007) deals with a stator winding whose turns are composed of segments. This is intended to improve the insulation in the area of the winding ends.

The DE 10 2018 101 231 A1 (Applicant: Brusa Elektronik AG; Disclosure date: July 25, 2019) describes a motor winding in a stator in which shaped strands are arranged in the longitudinal grooves of the stator, but the electrically conductive connecting elements are connected from one end of a shaped strand to the other end of another shaped strand Formed strands are to be joined. The actual implementation of the in the DE 10 2018 101 231 A1 The manufacturing technology mentioned is likely to be difficult, or at least requires large winding heads, because the shaped strands have to protrude far enough from the slots in order to enable joining technology such as welding or soldering.

Task

Electromobility regularly requires electric machines that are as compact and powerful as possible. It is desirable to be able to produce high-quality components, such as the stator, of electrical machines in large series. The electric machines should, if possible, work reliably even under changing operating conditions. Particular attention should be paid to a good fill factor for conductor material, especially for the stator windings, as well as to the best possible electrical connections.

Description of the invention

The object according to the invention is achieved by a method for producing a line segment for a winding of an electrical machine according to claim 1; a suitable method for producing a stator can be found in claim 14. A drive train for a motor vehicle emerges from claim 15. Advantageous further training can be found in the dependent claims.

A winding or the windings of an electrical machine, in particular of its stator, comprise several line segments. A stranded wire is used to produce a cable segment. The strand consists of several stranded wires, which can also be referred to as individual wires. Each individual wire is individually insulated by a coating. A coating with a thinly applied wire enamel may be sufficient to prevent possible current flow from an individual wire to a parallel individual wire. The stranded wires are preferably arranged bundled next to one another, with the individual stranded wires being twisted together. Twisted stranded wires extend in a curve next to each other in a bundle. The twisted stranded wires extend over a region of the line segment's longitudinal extent, which can be referred to as the middle region. As a bundle, the twisted stranded wires have a cross-sectional shape that can be described as a round shape or a circular shape. The twisted strand is usually straight across the entire length of the shaped strand. To produce the line segment, at least one bend in the strand is advantageously made, through which the strand is brought into a curved shape. Preferably, the arms of the strand extend linearly away from the curvature in a first direction and in a second opposite direction. The strand curvature in the first, middle region of the line segment is thus flanked by a second non-curved region and a third non-curved region along the longitudinal extent of the shaped strand. In the second area and in the third area the strand is pressed into a bar conductor shape. On the one hand, this compacts the strand. On the other hand, the strand is brought into a cross-sectional shape that is desired for inserting the strand into an electrical machine. The rod conductor shape is preferably a linear shape of the line segment formed in the respective strand area. The longitudinal extension of the shaped strand merges into so-called end areas at both ends. The end areas can be continuations of the bar ladder shape. The stranded wires can be twisted in the end areas. Two flat wires provided are added to the shaped strand. Both flat wires each have at least one end region on which there is no insulator. A central region of the flat wire is preferably all around, e.g. B. insulated with a thin layer of wire enamel. Each end region of the shaped strand is brought together with an insulator-free end of a flat wire. An end region of the longitudinal extension of the shaped strand is pressed together in an overlapping manner with the end region of the associated flat wire. Flat wire and shaped strand are brought into a metallically coherent connection in a respective first end region. A second flat wire is connected with its first end in the same way to a second end region of the longitudinal extension of the shaped strand.

The compression ensures that the strand cannot spread out of the bar conductor cross-sectional shape in the overlap area. The connection can e.g. B. can be produced by an energy input. A fusion of the two parts, the shaped strand and the flat wire, creates a metallic conductivity, which preferably develops over the entire contact area of the end areas, in particular without inclusions that hinder current conduction.

A stator includes a core, which can also be referred to as a winding core. The winding core carries the stator coils. A core that is constructed as a laminated core is particularly advantageous for guiding or forming a magnetic field. The core includes numerous rod conductors. The core preferably has a cylindrical shape. More precisely, the core is designed like a hollow cylinder, with a rotor axis extending through a center of the core. The rotor axis is an axis of symmetry that passes through a cavity in the stator. The rod conductors are arranged around the rotor axis in the core. A radial distribution of the bar conductors results when at least a second group of bar conductors is at a greater distance from the rotor axis than a first group of bar conductors. If the arrangement of the rod ladders is considered comprehensively, two rod ladders can be evenly spaced apart. If the core is designed as a laminated core, the bar conductors, preferably all of the bar conductors, are arranged in an interior of the laminated core. A receiving area for rod conductors in the laminated core, designed as a groove, can extend into the laminated core, leading away from the rotor axis. The bar conductors are in particular arranged electrically insulated from the laminated core. All bar conductors extend in the longitudinal direction or along the rotor axis of the stator. The rod ladder design is based on a hairpin design. In the shape of a hairpin, the rod conductors extend as compact rods, preferably straight, through the core or from one end face of the core to an opposite end face of the core. The rod conductors are designed as shaped strands. A shaped strand belongs to a line segment for electrical current. The line segment can also be referred to as a conductor segment. The shaped strand is long enough to accommodate at least two rod conductors. A first rod conductor is connected to a second rod conductor via an area of the shaped strand. The first rod conductor is formed on one arm of the shaped strand and the second rod conductor is formed on the other arm of the shaped strand. Each arm of a shaped strand has an end region. The bar conductors of the stator are arranged in the core in such a way that both end regions of the arms present on the shaped strand open out on the same side, in particular on the same end face, of the core.

The stator also includes a number of interconnection webs. A wiring bridge connects two rod conductors with each other. In other words, a wiring web is an electrical conductor for forming an electrical connection between a first shaped strand and a second shaped strand. The interconnection web extends directly, i.e. i.e., without intermediate loss resistance, from an end region of a first shaped strand to an end region of a second shaped strand. The end areas each merge into a rod conductor. It is particularly advantageous for the formation of a web interconnection if the interconnection webs are constructed in two parts. Both parts of a wiring web are each implemented by a flat wire. The flat wires preferably consist of the same metal. A flat wire is an electrical conductor whose height or thickness is smaller than its width. A flat wire can have a rectangular cross section. It is possible to provide flat wires as strip material or as punched sheet metal strips. Each flat wire preferably has wire enamel insulation. This means that the formation of short circuits between two connection bars is almost impossible. The interconnection webs are arranged outside the core. Interconnection bars can also be referred to as interconnection bridges.

Because a winding in a stator has a sequence of alternating shaped strands and interconnection webs, one can speak of a hybrid winding design of a stator according to the invention.

Thanks to the hybrid structure of the winding, the stator can be manufactured comparatively easily. Electrically conductive connections between shaped strands in the stator and the wiring webs can be used in large-scale production processes, e.g. B. through synchronous contacting, time-efficient and reliable. With the shaped strands, the stator can have a very good conductor filling factor for power conduction through the windings.

A stator produced according to the invention and the production method according to the invention for line segments can be used advantageously to provide a drive train or for an advantageous drive train of a motor vehicle. The drive train has an electric machine for generating torque. The torque can be generated with a stator, which is usually installed stationary in the motor vehicle, and a rotor rotatably arranged therein. The rotor is preferably equipped with a magnet arrangement equipped, which can be formed from permanent magnets. By supplying alternating current, variable magnetic fields can be generated, through which a force applied tangentially to the rotor enables the rotor to rotate. That rotational movement or the associated torque is introduced into a torque transmission device. The torque transfer device may include one or more of the following components: an input shaft, an output shaft, a spur gear, a clutch, a planetary gear, a brake, and/or a differential. With a suitable current supply to the stator, a torque acts from the torque transmission device on a road wheel (in the case of a single-wheel drive) or on several road wheels. The energy for the drive is provided from a rechargeable energy source in the motor vehicle. The required electrical current can be supplied to the electrical machine e.g. B. can be supplied in a controlled manner via power electronics that includes an inverter.

Advantageous refinements and further developments are presented below, which can also reveal inventive aspects, both individually and in combination.

The shaped strand preferably acquires its cross-sectional shape at least in some areas by compression molding. The twisted strand can be particularly compacted thanks to compression molding. This enables a good filling factor in a groove (for example, a proportion of 0.5 to 0.95 of the groove volume can be filled with conductor material). Three strand segments can be formed along a longitudinal extent of the strand by compression molding. The strand segments are areas in which the strand has been given a geometric cross-sectional shape that is different, in particular from an adjacent area. Preferably at least seven strand segments are compression molded. It is advantageous if a strand cross-section along the longitudinal extent of the strand has a different cross-sectional shape for two of the compression-molded, preferably spaced-apart, strand segments, which preferably each extend linearly and serve as a rod conductor. A strand cross section of two strand segments, which in particular connect to the rod conductors, can be designed to be identical to one another. These strand segments can have the same length in pairs. There is preferably an unpressed strand area between two strand segments with the same strand cross section. An unpressed strand area is easier to bend compared to the compression-molded strand.

The two rod conductors formed by a shaped strand or impressed into a shaped strand preferably have the same length. The length of the bar conductor is selected according to a longitudinal extent of the core or the laminated core along the rotor axis. In other words, the rod conductors can extend beyond the core by a few millimeters (e.g. 5 mm). Preferably (only) a respective compaction area of the shaped strands protrudes beyond the core.

An insulator layer can be applied to the shaped strand. Covering the shaped strand with an insulator material ensures that no currents can flow from the shaped strand onto the core. The insulator layer can extend over the entire bar conductor. It is also possible to provide an insulator layer that covers the entire length of the shaped strand.

Several individual wires are arranged next to each other in the shaped strand. The individual wires are twisted together. The individual wires extend in the shaped strand from a first strand end to a second strand end. A twist of the stranded wires is preferably created or provided with a lay length. A twist with one lay length can be referred to as a 360° twist. Between the first strand end and the second strand end, the twist is preferably an integer multiple of a lay length. An overlap area of those two electrical conductors is preferably present between the two end regions of the shaped strand and a respective end region of the flat wire connected to the shaped strand. An overlap area can e.g. B. be a predetermined length on the longitudinal extent of the strand, which is in a range from 4 mm to 20 mm. The overlap area lies along the longitudinal extent of the strand in an end region of the strand. The overlap enables better contact formation.

A first end of the shaped strand belongs to a compacting segment of the shaped strand. At a second end of the shaped strand there is a second compacting segment of the shaped strand. The first compaction segment is connected to a first flat wire. The second compaction segment is connected to a flat wire. The connection between a compacting segment and a flat wire end area is made using compression molding. Preferably, at least the end region of the respective flat wire assigned to the compacting segment is free of wire enamel. An electrically conductive connection can e.g. B. can be created by soldering, welding or crimping. During compaction, an electrically conductive transition from all individual wires to the flat wire is created via respective segment contact surfaces.

The shaped strand has several cross-sectionally shaped strand segments. The strand was subjected to compression molding on each cross-sectionally formed strand segment of the formed strand. Compression using a roller is possible. Preferably, due to the different cross sections to be formed on a strand, shaping takes place in a press mold. The mold determines the cross-sectional shape. Individual wires are moved collectively at the same time. All strand segments can in particular be brought into their respective cross-sectional shape at the same time by compression molding.

There is an equal number of individual wires in each strand segment. The result is an approximately equal strand cross-sectional area due to the compression molding. In other words, each cross-sectionally shaped strand segment has the same conductor cross-sectional size. The specified strand cross-sectional area size is advantageous for the power line.

The flat wires present in the stator can be assigned to a first group and a second group. Flat wires of the first group have a first flat wire width. Flat wires in the second group have a second flat wire width. The flat wires of the first group are each connected to a first end of an individual shaped strand assigned to them. The flat wires of the second group are each connected to a second end of an individual shaped strand assigned to them. The first width of the flat wires in the first group is smaller than the second width of the flat wires in the second group. The width of the flat wires is chosen so that it is narrower than an inlet opening of a core groove. There are preferably at least two rod conductor areas in each core groove, which belong to at least two flat wires. The flat wires can therefore advantageously be inserted into the core groove in an axial direction. A web connection, ie the formation of a connection web, is possible using two flat wires. Stripped or insulation-free end regions of the flat wires are preferably connected to one another to form a wiring web.
Creating an electrical connection can be done by laser beam welding or another form of beam welding (e.g. with a charge carrier particle beam). Web connections are particularly low-resistance connections from a first shaped strand to a second shaped strand. The connection is created through material closure, e.g. B. from copper to copper.

A particularly high filling factor can be achieved if the bar conductors of the shaped strand are adapted with their cross-sectional area to a cross section of a receiving space for the bar conductor in the stator. If the receiving space has a trapezoidal shape, in particular a trapezoidal shape represents the cross section of a longitudinal extent of the receiving space, a shaped strand of the stator is preferably also equipped with a trapezoidal shape.

The cross section of the first bar conductor can fill a first trapezoidal shape. The cross section of the second bar conductor can fill a second trapezoidal shape. It is particularly advantageous if both trapezoidal shapes have the same trapezoidal angle. Two trapezoidal shapes fit together even better if a smallest width of the first trapezoidal shape and a largest width of the second trapezoidal shape approximately match. A favorable trapezoidal angle results in particular from the radius that a rotor-side core inner wall follows and the number and width of grooves in the core. The first trapezoidal shape and the second trapezoidal shape can be put together almost seamlessly. Both trapezoidal shapes together form a trapezoidal height, preferably corresponding to a depth of the groove, of which the second trapezoidal shape can take up a larger proportion than the first trapezoidal shape.

It is particularly advantageous for assembling the stator if the flat wire has a maximum width over its entire length, but at least over one end of the flat wire, which is matched to the width of the bar conductor to which the flat wire merges. A maximum flat wire width is preferably less than or equal to a bar conductor width. In addition, a maximum height of the flat wire should be less than or equal to the height of its connected rod conductor. This means that the cable segments made of flat wire and shaped strand can be inserted particularly easily into the core.

Between the two arms of a shaped strand there is a central region of the shaped strand which serves as a spacer from one arm to the other arm. In other words, the middle region forms a bridge between a first arm and a second arm of the shaped strand. The center area is preferably a segmented area. The shaped strand has at least two transition segments in the middle area. At least one transition segment is designed with a cross-sectional compression mold. The segments in the middle area can also be referred to as shaped strand head segments. Accordingly, there can be at least three shaped strand head segments. A cross section of the transition segment is essentially rectangular. This means that a rectangular area is filled as a cross-sectional area by the individual wires of the shaped strand in the transition segment. Due to the round shape of individual wires that is usually used, there can be small gaps between the individual wires, for example. B. by one Insulating varnish and/or a baking varnish can be filled. If three transition segments or three shaped strand head segments are formed on the shaped strand, two of the segments or two transition segments preferably have the same rectangular cross section. The rectangular cross section of the transition segments is uniform over the length of the transition segments due to the compression molding.

A shaped strand head area can be formed between the two arms of a shaped strand. The shaped strand head area is a shaped area of the strand that is arranged in a winding head of the stator or is intended for an arrangement in the winding head in a construction phase. It is particularly advantageous if the shaped strand head area has a (first) strand curvature. The curvature can be formed by loop forming, e.g. B. if the loop is stretched by pulling the two arms apart. A curvature formed in this way can result in an increase in the transverse extent of the shaped strand. In that shaped strand head area, which is preferably located in a central area of the shaped strand, a transverse extension of the shaped strand is greater than in a rod conductor area. When loop forming, the shaped strand or the shaped strand head area is brought into a loop-like extension. This preferably creates a track offset from one bar conductor to the adjacent bar conductor on a shaped strand. In the area of the curvature of the shaped strand head area, the shaped strand has not been exposed to any cross-section-determining pressure. This means that in that shaped strand head area, the softness of the shaped strand is at least preserved or slightly improved in accordance with the bendability of the twisted strand. This makes it easier to bend the shaped strand into a desired (spatial) 3D shape for positioning the rod ladder. In addition, a flatter winding head can be formed.

The stator is equipped with at least one winding for power conduction, with a current passed through generating a magnetic field around the winding. The winding is supported by the core of the stator. The winding, which is also referred to as a coil, is formed from a sequence of shaped strands and connecting bars. A shaped strand follows a connection bar. A shaped strand follows a wiring web. The shaped strands in combination with two flat wires each can preferably be inserted into the stator at the same time. Both arms of a shaped strand are inserted into different grooves in the core. A first rod conductor of a shaped strand sits in a groove, preferably in an inner radial region of the groove, and a second rod conductor of the same shaped strand sits in another groove, preferably in an outer radial region of the other groove. Between those two grooves, further grooves can be present in the core or the laminated core, which are bridged in a winding head by one or more shaped strand head segments. In another winding head of the stator, several slots are bridged by a wiring web.

The combinations and exemplary embodiments presented above can also be considered in numerous other connections and combinations.

A stator for an electrical machine can be equipped with a laminated core in which a plurality of grooves are present. The grooves are preferably incorporated evenly distributed over the circumference, e.g. B. punched from the sheets that form the laminated core. The laminated core has a hollow cylindrical basic shape. This basic shape can be assigned an outer jacket and an inner jacket. The inner jacket can also be referred to as the inner wall of the laminated core. The grooves branch off into the laminated core via a gap in the inner wall of the laminated core (formed from individual metal edges). The grooves preferably extend in the longitudinal direction along the entire laminated core and can have a rectangular cross section or a trapezoidal cross section. The hollow cylindrical shape of the laminated core has two end faces. A first winding head sits on a first end face. The first winding head is formed from arcuate central regions of a large number of shaped strands. The shaped strands are shaped like a hairpin. This includes, in particular, two linear extension areas that are connected via a transverse extension area of the shaped strand. A second winding head is located on a second end face of the laminated core. The second winding head serves to connect the shaped strands to one another, in particular according to a predetermined winding structure plan or wiring plan. In other words, the first winding head preferably has no contact points of the turns because the contact points are all located in the second winding head.

There are exactly two shaped strands in each groove. Both shaped strands extend from the first winding head to the second winding head. The second winding head includes a large number of wiring bridges. A wiring bridge leads from a first shaped strand to a second shaped strand. At least two contact points are present on a line route between a first shaped strand and a second shaped strand. A contact point is an electrically conductive connection. That connection is designed with mechanical stability in that the connection is via a contact surface. These are the two shaped strands coupled to a wiring bridge is a shaped strand which is arranged in a first groove radially closer to the inner wall of the laminated core. That shaped strand is inside the first groove. The other shaped strand, which belongs to the wiring bridge, extends in a second groove. In that second groove, the shaped strand lies on a side of the groove facing away from the inner wall of the laminated core. It can also be referred to as an external shaped strand. The inner wall of the laminated core serves to limit an air gap to the outside of a rotor.

In an advantageous method for producing a stator for an electrical machine, a laminated core is provided which has a predetermined number of grooves. A predetermined number of shaped strands is also provided. The shaped strands are each equipped with a connecting bar, such as a flat wire, at both end areas. A connecting bridge is used to provide a passage of electricity. In a first shaping step, which is a bending step, a central region of the shaped strands or each shaped strand that serves the stator structure is curved in a shaped strand plane and thus brought into a U-shape. In one joining step, all the shaped strands of the stator are inserted into the grooves in a longitudinal direction of the laminated core with the connecting webs first. The insertion is preferably carried out for all shaped strands at the same time. For joint insertion, the shaped strands can be inserted into an insertion tool in advance. All shaped strands are pushed in particular next to each other or in pairs next to each other through the entire length of the groove until their connecting web protrudes from the laminated core on one side of the second winding head. Two connecting webs, which belong to different shaped strands, are then bent together or towards each other. The connecting webs brought together form an electrically conductive connection, which is preferably achieved by a uniform shape of the connecting webs, e.g. B. supported by a pinch, a solder, a sheathing band, a contact shoe and / or an introduction of thermal energy.

An assembly of an advantageous stator according to the invention with a rotor provided forms an electrical machine with which torque can be generated for a motor vehicle.

The result is a particularly compact electrical machine.

Further advantageous refinements and further developments are presented below, which can also reveal inventive aspects, both individually and in combination.

An interconnection of line segments can be carried out particularly quickly and almost error-free if a winding area of the second winding head, preferably the entire winding area of the second winding head, which connects to the shaped strand segments in the laminated core, is designed to be free of shaped strands.

The interconnection web bridge is preferably formed from at least two interconnection web sections. The interconnection web sections can be attached to one another in an electrically conductive manner on one side in a V configuration or a Y configuration. Preferably, the interconnection web bridges and the interconnection web sections each have a rectangular cross section. If there are exactly two interconnection web sections between two shaped strands, these interconnection webs are connected to the interconnection web bridge on one broad side of their rectangular cross section.

A wiring web section preferably has a width over an entire section length that is less than or equal to a width of a shaped strand connected to the wiring web section in an electrically conductive manner. In a corresponding manner, the interconnection web section is preferably designed in relation to a predetermined height of the connected shaped strand. This ensures that the interconnection web section can be passed through a groove in the laminated core.

In order to gain an even better understanding of the stator wiring, a perspective can be taken looking towards a stator casing. A first interconnection web section of a first interconnection web bridge and a second interconnection web section of a second interconnection web bridge appear in such a shell side view of the stator as interconnection web sections arranged in different planes, which lie one above the other in a mutually crossing manner. The interconnection webs can thus form a particularly compact or dense arrangement in a second winding head.

The shaped strand is preferably a strand pressed into a cross-sectional shape. A plurality of strand segments are preferably formed along a longitudinal extent of the strand, the number of which can in particular be an odd number such as three strand segments or seven strand segments. A first strand cross section of a strand segment differs from a second strand cross section of an adjacent strand segment. An advantage of one The reason for the odd number is that the strands between the two shaped strand segments in the laminated core can be folded together particularly well. In addition, an orientation of those two shaped strand segments can be set particularly precisely during stator production.

The first winding head is formed by at least two shaped strand head segments, each of one of the shaped strands of the stator making up at least one turn. The two shaped strand head segments have a preferably uniform, rectangular strand cross section. A first broad side of a first shaped strand or a shaped strand head segment faces a second broad side of a second shaped strand in the stator, to which the other shaped strand head segment belongs.

A good compactness of the (first) winding head can be achieved if a width of the broad side of the shaped strand head segment is at least twice a height of the high side of the shaped strand head segment.

Between two shaped strand head segments there is preferably a third, in particular unpressed, shaped strand head segment, the strand extension of which has a screw thread-like curvature, such as a loop. The third shaped strand head segment can form a coil head if it is at the furthest distance from all shaped strand head segments from a laminated core side. A height of the third shaped strand head segment can be approximately 0.8 times a diameter of the shaped strand in the unpressed round shape. In particular, two rectangular shaped strand head segments with a width to height ratio of 2.5 or more are easier to fold if there is a third shaped strand head segment in between.

The stator has at least one winding for power conduction, which is designed as a repeating sequence of a shaped strand and a wiring bridge. All windings of a stator can be designed as such a sequence. Each winding preferably has at least one winding end, which is designed as a contacting strand. The contacting strand is used to introduce or discharge electrical current. The stator can be easily installed if the contacting strand ends in an electrical plug connector or an electrical screw connector.

The shaped strand can be wrapped from one interconnection bridge to the next interconnection bridge by a fabric tape or a polyimide tape or a fluoroethylene propylene tape or a polyethylene naphthalate film. It is also possible to form a wrap from a first shaped strand to a second shaped strand. It is particularly useful to wrap the shaped strand in the area that extends in the laminated core because that area is difficult to cast. The shaped strand can also be additionally coated with a wire varnish, such as a polyester immide varnish, or a synthetic resin or an epoxy for insulation, particularly in an area of a first winding head. A particularly well-insulated stator can be provided if the second winding head, in particular the wiring bridges, are also cast with such an electrical insulation material.

The stator can be equipped with cooling to reliably deliver higher engine power. A cooling liquid can be passed into the first winding head and/or into the second winding head and/or into the laminated core to cool operational heat. Preferably, a coolant line is provided for passing coolant through the stator and is attached to the outer jacket. In addition, one or more cans can pass through the laminated core.

The winding heads each have a diameter transverse to a rotation axis or rotor axis of the stator. A diameter of the first winding head can be smaller than a diameter of the second winding head. Preferably, a height of the first winding head along the axis of rotation is smaller than a height of the second winding head along the axis of rotation.

A stator can be manufactured particularly labor-efficiently if a number of shaped strands is equal to a number of slots. This makes it easy to handle a number of parts that have to be assembled for a stator.

When producing a stator, a second bending step is preferably carried out on the shaped strands before the shaped strands are inserted into the laminated core. In the second bending step, a shaped strand, preferably all shaped strands, are positioned in a direction that leads out of a shaped strand plane, with at least one curvature in the shaped strand head area. In particular, a track offset that the shaped strand offers is increased.

It is particularly advantageous for the production of the stator if the shaped strands are pushed into the grooves of the laminated core with both connecting web sections of a shaped strand first. A connecting web section can also be referred to as an interconnection web section. One of the connecting web sections can, in particular using an assembly tool, are inserted into a first groove and the other of the connecting web sections are inserted into a second groove of the stator. It is particularly advantageous for further processing of the connecting web sections if the connecting web sections are pushed in until the connecting web sections that have entered a groove entrance have completely emerged from a groove exit.

In a processing step of the stator production, which can be carried out additionally if desired, a winding head can be compacted even more. The compaction is preferably carried out using a plate-like compaction tool. The shaped strands are compacted in a central region of the shaped strands which forms a winding head. By applying a pressure force in the direction of the rotor axis, the shaped strands of the stator are pressed together against the laminated core and thus bent towards the laminated core.

A first group of connecting web sections can be longer than a second group of connecting web sections. This makes it easier to interlace the connecting web sections. Interleaving connecting web sections in pairs, a section from the first group and a section from the second group, is preferably carried out simultaneously with an entangling tool.

An electrically conductive connection between the two connecting web sections can be produced by energy treatment of a contact point of the connecting web sections. The connection can be made by beam welding. It is particularly advantageous if the entanglement tool is equipped with a beam welding device so that a connection can be created at all welding points in a common manufacturing step.

The combinations and exemplary embodiments presented above can also be considered in numerous other connections and combinations.

A line segment is preferably used to produce a winding of an electrical machine. The line segment is made up of metallic conductive segments, of which at least two segments can be distinguished as sections of the line segment. One can also speak of sub-segments of the line segment. A first segment or sub-segment has a shaped strand. The first segment can consist of the shaped strand. A second segment has a flat wire. The second segment can consist of the flat wire. The shaped strand is formed from several individual wires twisted together. The flat wire can be a strip wire. The shaped strand has a first compression-molded end region. In that end area, the shaped strand was subjected to compaction. Individual wires of the shaped strand are preferably arranged particularly densely in the end region. It can also be referred to as a compacting segment or compacting sub-segment of the shaped strand. The compaction segment is overlapped by a flat wire end area. It can also be said that the compacting segment is formed by laterally pressing the flat wire end area onto the shaped strand or onto a shaped strand end area. The shaped strand and the flat wire are arranged at a line segment angle to one another. A transition between shaped strand and flat wire takes place with an angle that is set from an angle range of 180° to 100°. Formed strand and flat wire are firmly connected to each other. The composite has metallic conductivity. In other words, current can pass from the shaped strand into the flat wire or from the flat wire into the shaped strand almost without resistance (e.g. when alternating current is supplied).

The production of a line segment is based on combining a shaped strand with at least one flat wire. A first end region of the shaped strand is arranged on a first flat wire end region, with an intermediate layer of brazing solder being inserted between the two end regions. One can also speak of the formation of a three-layer system. Formed strand and flat wire are aligned or arranged with a line segment angle to each other. For compaction, a pressing pressure is simultaneously applied to the first end region of the shaped strand and the first flat wire end region as well as the brazing solder, i.e. to the three-layer system, and a brazing solder melting heat is supplied. The braze melting heat can e.g. B. can be introduced by diffusion welding. With sufficient heat, the brazing solder melts and spreads out, removing any gaps that may exist, e.g. B. between individual wires. A predetermined transition connection between the shaped strand and the flat wire is created with the selected transition angle.

By melting the brazing solder, both the flat wire is wetted with brazing solder in the entire flat wire end area and the shaped strand is soaked with brazing solder in the end area of the shaped strand. It is particularly advantageous if an area size of the brazing solder is equal to an area size of a shaped strand contact area and an area size of a flat wire end contact area.

With the help of the advantageous line segment or a large number of advantageous line segments, a winding of an electrical machine can be formed, which, for. B. due to their compactness, a space-efficient structure of a drive train is possible, which, when installed in a motor vehicle, enables installation space to be released for other components or can also simplify production of the motor vehicle by making component assembly easier.

Advantageous refinements and further developments are presented below, which can also reveal inventive aspects, both individually and in combination.

It is particularly advantageous for the conductivity of the shaped strand if all of the stranded wires of the shaped strand extend from a first end of the line segment into the flat wire end area. Each stranded wire can be individually covered with an insulating wire enamel layer. This means that each individual conductor is considered a separate power conductor. The insulation layer of external individual conductors also protects against short circuits. A double layer of lacquer on each individual wire or stranded wire is very advantageous. With a double layer, a layer of wire enamel can be covered with an outer layer of baking varnish. The double layer preferably makes up less than 10% of a stranded wire diameter. A total diameter of the stranded wire preferably has a value in a range of 0.3 mm to 1.2 mm.

The stranded wires can be twisted with one lay length. The lay length indicates a distance after which the twisted stranded wires return to their original position. This distance preferably corresponds to a total length of the shaped strand of the line segment. This length of return can also be equal to half or a third of the total length of the shaped strand. Maintaining a total lay length is beneficial for AC transmission.

The flat wire can be insulated with a wire enamel. The use of an insulated flat wire, in particular combined with insulated stranded wires, facilitates on-site isolation of the stranded segments when installed. In particular, areas are protected that may be shaded against paint spraying when installed. For contacting the flat wires or connecting a flat wire to a shaped strand, it is advantageous if the two ends of the flat wire are not coated with a wire enamel or if the wire enamel is removed from the end regions after flat wire pieces have been cut to length, e.g. B. is removed with a solvent. The end areas of the flat wire should at least be on the contact surfaces, i.e. the surfaces on which z. B. a shaped strand or another flat wire is to be applied, must be free of wire enamel.

For creating a connection between the shaped strand and the flat wire, it has proven to be particularly advantageous if the flat wire end region is designed with at least one compacting bevel. The compaction slope is beneficial for a more even distribution of force when the flat wire end area and the shaped strand end area are pressed together. A first compaction slope is located at the extreme end of the flat wire. This slope prevents possible shearing of individual wires during compaction. A second compaction slope is located in the area of the flat wire that is assigned to an outermost end of the shaped strand. This compaction slope is, among other things, advantageous to largely prevent possible spreading of the shaped strand. The flat wire is stepped onto a contact surface between the first compaction slope and the second compaction slope. The contact surface can extend approximately in the middle of the flat wire, based on a maximum height of the flat wire. Preferably the contact surface is parallel to a flat wire surface. It can also be said that the flat wire is made sufficiently thinner in its end region (e.g. ground) so that the compacted shaped strand end region can fit thereon without exceeding a predetermined maximum height of the flat wire in the compaction segment as a whole. The flat wire end region is preferably tapered towards its end in the region of a segment contact surface. A compacting bevel is particularly advantageous if its bevel angle is in an angular range of 10° to 70°, e.g. B. is designed at 45 °.

The shaped strand segment can, among other things, to form a rod conductor, be pressed into a geometric cross-sectional shape. A first shaped strand segment of the shaped strand can be used to form a first rod conductor. The first shaped strand segment is preferably pressed into a first trapezoidal shape as a cross-sectional area. A second shaped strand segment of the same shaped strand can be used to form a second rod conductor. The second shaped strand segment can be pressed into a second trapezoidal shape as a cross-sectional area. It is particularly advantageous if both trapezoidal shapes have the same trapezoidal angle. It is also advantageous if both trapezoid shapes can be placed next to each other in a stepless manner.

Two trapezoid shapes fit together particularly well if the first trapezoid has the smallest width and the second trapezoid has the largest width shape roughly match. When the trapezoid shapes with those widths are put together, a larger trapezoid results. The trapezoidal shapes are preferably chosen so that a trapezoidal groove can be filled almost completely. The second trapezoid shape can have a greater height than the first trapezoid shape if both trapezoids have the same area. The surface area is determined by a cross-sectional area size of the shaped strand. By pressing, the shaped strand can be brought into a more space-saving packing of the individual wires in at least one of the trapezoidal shapes with a compression factor of a value between 0.6 and 0.96 based on a strand cross-sectional area size of the twisted stranded wires.

A second compression-molded end of the shaped strand can also be compacted. During compaction, a greater pressing force can be exerted on the formed strand than during compression molding. An upper limit for the force is achieved by preventing the conductor material from flowing out, e.g. B. copper, set from a compaction mold. The second end region of the shaped strand can be connected to a second flat wire end region of a second flat wire. It is a metallic conductive connection. The arrangement of the second flat wire and shaped strand includes a second line segment angle. The first line segment angle may be equal to the second line segment angle. In particular, the second line segment angle can have a value in a range from 180° to 160°, preferably exactly 180°. This means that the line segment can be easily threaded into a groove (axial) or a hole or pressed laterally (laterally) into a gap or slot.

The compression-molded end region of the shaped strand preferably extends over a compaction length. In the area of the compaction length, the shaped strand can be covered by a copper foil in combination with a flat wire. The copper foil preferably has a foil thickness that is in a range of 0.1 mm to 0.5 mm. This means that the copper foil can be applied particularly well to flat wire and shaped strands. A compaction length can have a value from a range of 2 mm to 25 mm. The compaction length is preferably 4 mm to 12 mm, for example 6 mm. A shorter compaction length allows a lower height of the (second) winding head. A longer compaction length can provide better mechanical strength. The compacting area is preferably pressed together with the copper foil or a correspondingly arranged copper bath. This creates particularly good contact. The copper tape or copper foil is a cable bridge that connects shaped strands and flat wires.

A conductance of the compaction area becomes particularly high if a brazing solder is used for an even better bond between shaped strand and flat wire. A hard solder is preferably present at least on one contact surface between the compression-molded end region of the shaped strand and the flat wire end region. The brazing is as a brazing plate, which e.g. B. can have a compaction length and a width of the flat wire end area, i.e. is a rectangular plate, can be placed on the contact surface of the flat wire end area before the shaped strand end area is positioned thereon. A brazing layer can e.g. B. arise from the brazing plate by heating. A brazing layer on the contact surface ensures a better electrical connection. The hard solder can initially be introduced in a limited manner between two compacting bevels that may be present. By applying compaction pressure, the brazing solder can also be distributed over one or both contact bevels on the contact surface. This makes it possible to create a complete compaction area.

The flat wire preferably has the same width as the shaped strand or a smaller width than the shaped strand. This means that the combination of flat wire and shaped strand can be pushed into or through an opening without getting caught with the flat wire.

When producing the shaped strand or the production of the line segment, at least one curvature in the extension of the strand can be created in a central region of the shaped strand. A U-shaped curvature is advantageous for arranging the shaped strand in a stator. The shaped strand can be pressed into a linearly extending rod shape in one or two extension areas, which are spaced from the curvature or the strand curvature, which can also be referred to as a rod conductor shape. This ensures the formation of a turn, e.g. B. in a sheet metal package, made easier.

The line segment can be covered with insulation. An advantageous option for insulation is to wrap the line segment or at least areas of the shaped strand with an insulating tape. It is often sufficient if the wrapping extends track by track, preferably laterally overlapping, starting at a first flat wire end area and extending in front of a second flat wire end area. This leaves the end areas free for contact formation. Preferably, only those areas in which wire enamel could be rubbed off on edges or contact surfaces and conductor material could be rubbed bright are wrapped. This includes an area of a winding head, which in particular is exclusively of Formed strands can be formed, as well as inlet openings or outlet openings in grooves. This prevents possible short circuits even when operating under strong vibrations.

Further advantageous aspects can also be described as follows, which can make an inventive contribution both individually and in combination with one another.

Shaped strand:

A shaped strand consists of several enamel-insulated individual wires. The wires usually have a diameter that is in the range of 0.3 mm to 1.2 mm. Depending on the wire diameter, a predetermined number of individual wires are bundled into a stator for the shaped strands. For example, 15 to 200 individual wires can be bundled and twisted into a strand with a specified lay length. Alternatively, the lay length can also be produced using the manufacturing processes of stranding, stranding or twisting. It is particularly advantageous if the lay length is equal to or a multiple of an active length of the electric machine for which the stator is intended. With an active length of a laminated core of, for example, 120 mm (millimeters), the lay length should be either 120 mm, 60 mm or 40 mm. Within the lay length, the wires make a helical twist of 360° (degrees) around a central axis of the bundle of individual wires.

Twisting individual wires with the appropriate lay length significantly reduces frequency-dependent losses (AC losses) that occur during operation of the motor or electrical machine. The advantageous twisting of individual wires in a shaped strand improves the performance and efficiency of the electric machine.

The twisted strand can be compacted by an additional twist, with a helical loop being formed and pulled together in a coil head area of the shaped strand.

The twisted strand can be compacted in a pressing tool. Preferably, compression occurs in a manufacturing process that follows bundling and subsequent twisting. Alternatively, the strand can also be compacted by rolling. Experiments have shown that pressing can achieve greater compaction than rolling, which is why pressing is a preferred method. The ratio between the sum of the pure wire cross-sectional area of enameled wire-insulated, bundled individual wires to the total cross-sectional area of the shaped strand can be referred to as the compression factor. This value is usually in a range of 0.6 to 0.96.

Ideally, a geometric shape is chosen for compression into a shaped strand that is based on the cross section of the stator slot. An electrical machine can have square groove geometries, i.e. H. have parallel boundaries of the groove, which are equipped with square flat wires. Particularly advantageous for a particularly good continuous performance of an electrical machine is a stator with annularly arranged, trapezoidal grooves, the boundary walls of which extend towards one another at a predetermined angle in the direction of an axis of rotation.

Preferably, a small clearance, such as a distance with a size corresponding to a value in the range 0.1 mm to 2 mm, is provided between the shaped strand and the groove in order to allow the shaped strands to be inserted into the groove or grooves, in particular the respective position of the shaped strands along a radial direction of the groove.

Another advantage of compaction by pressing or compaction in a press mold is that different cross-sectional shapes, in particular different geometric shapes of a cross-sectional area, such as a round shape, e.g. B. circle or oval, a trapezoid, a rectangle or a square can be formed.

Along the shaped strand, the shaped strand can in a first area, which can also be referred to as a rod conductor area, have a height of the cross section with a value in the range of 3 mm to 12 mm and a maximum width with a value in the value range of 1.5 mm to 10 mm must be pressed. This is followed by a second area, which is in particular shorter than the first area. In the second area, the shaped strand can be pressed with a cross-sectional height that has a value in the range of 5 mm to 20 mm and a width that has a value in the range of 1 mm to 7 mm. Across a coil head area spaced apart from the second area, there is preferably a third pressed area which is equipped with a cross section of the same dimensions as the second area. A length of the third pressed region is preferably equal to the length of the second pressed region. In the non-pressed coil head area, the shaped strand can have a height in the range of 4 mm to 16 mm and a width in the range of 2 mm to 14 mm. The third pressed area is followed by a fourth pressed area. The fourth pressed area preferably has the same length as the first pressed area. A height of the fourth pressed area can have a value in the range of 4 mm to 14 mm and a (maximum) width with a value in the range of 1.5 mm to 8 mm. The fourth pressed area can also be referred to as the second rod conductor area of the shaped strand, because the fourth pressed area is also intended for insertion into a groove of a laminated core.

The values of the height and width of the pressed areas are also determined by the fact that this results in an almost constant area size of the cross-sectional area. One can speak of a boundary condition.

Cross-sectional shaping of the shaped strand:

If the shaped strand is designed to be trapezoidal like the groove in which the shaped strand is or is to be arranged, particularly good electromagnetic properties result. By compressing the shaped strand into the geometric shape that is optimally adapted to the groove, preferably trapezoidal, it is possible to increase a so-called copper filling factor. A high copper filling factor reduces the electrical resistance in the conductors and the direct current losses (DC losses) decrease. This leads to a further increase in the performance and efficiency of the electrical machine.

A strand made of twisted enamel-insulated individual wires is compacted and formed into different cross-sectional shapes in several different areas over a predetermined area length. While the cross-sectional shape differs in five consecutive areas of the shaped strand, the cross-sectional area, given by a sum of the cross-sections of the individual stranded wires, is constant in all areas. In a coil head area, however, there can be a lower degree of compression of the stranded wires than, for example. B. in the areas adjacent to the head area.

Two areas extending towards the ends of the shaped strand contain a cross-sectional shape, usually trapezoidal, which optimally reproduces the groove shape in the laminated core. The cross-sectional shapes of these two areas usually differ in height and width, since after joining in the laminated core they are located in different places in a different groove, i.e. i.e., at different radial positions.

Towards the middle of both shaped strand end areas there is a shaped strand transition area in which the shaped strand is pressed into a flat rectangular shape. The idea of pressing these two areas into a flatter shape has a significant advantage for the resulting winding head height. The winding head height depends on the width of the shaped strand and is smaller the flatter the strand can be compacted.

In the head area between those aforementioned transition areas, the strand can optionally be reshaped in a compressed manner by additional twisting. This makes it easier to place the transition areas together.

Flat wire:

The flat wire preferably consists of the same metal or the same metallic alloy as the shaped strand, preferably copper. A cross section of the flat wire is typically rectangular with the maximum width and height of the respective cross section that the shaped strand has in the bar conductor or groove area. The cross section of the flat wire can be square. The corners and edges of the flat wire are rounded. Optionally, the cross section of the flat wire can also be 0.1 mm to 4 mm smaller than the respective (maximum) width and/or height of the respective cross section of the shaped strand in its groove area.

The flat wire has enameled wire insulation. The flat wire is processed before it is welded to the strand. Several pieces of flat wire are cut to the required flat wire length. The flat wire is stripped at one (first) end. This end is used for contacting other (stripped) flat wires or flat conductors (another word for flat wire). The flat wire is also stripped of insulation at the other (second) end. The second end is used to connect to the shaped strand.

A bevel is incorporated into the flat wire at the end intended for the shaped strand. The slope is preferably created with an angle between 20° and 70°. The bevel is particularly advantageous for producing a very compact joint connection of the flat wire or its insulation-free end region with the shaped strand. The bevel serves to prevent individual conductors from being severed by the flat wire when joining the stranded wire. The slope can also be formed with a curvature or rounding.

When creating the joint, the flat wire and shaped strand are pressed together in an overlap area.

Severed individual conductors cannot conduct electricity and this prevents the risk of a reduction in the performance of the electric machine.

Joint connection between shaped strand and flat wire:

A joint between the shaped strand and the flat wire is created by compacting the shaped strand. A cross section of the joining connection is preferably smaller or equal to a cross section of the respective pressed rod conductor area of the shaped strand, in particular in relation to its height and its maximum width. This enables the rod conductor area of the shaped strand to be axially joined into the laminated core.

Although rod conductors can also be inserted into the laminated core in a radial direction, The groove opening in the laminated core must then be chosen to be larger, in particular so large that both the rod conductor and the shaped strand and their joint connection fit through the groove opening. A larger groove opening is usually associated with a loss of performance. In addition, automated assembly of a laminated core with bar conductors by inserting them in the axial direction is less complex than by inserting them radially into the grooves.

In the area of the joint connection, i.e. H. In the area of compaction, a conductive copper foil or a conductive copper tape is arranged as a sheath around the flat wire and the shaped strand. The thickness of the copper foil or copper strip is approximately 0.1 mm to 0.5 mm. This film or tape can be designed to overlap in one area. On the one hand, this copper coating has a reinforcing, mechanically reinforcing effect with regard to the compaction or the compaction area. On the other hand, the conductivity of the sheathing makes the resistance welding process possible for producing the cohesive connection between the shaped strand and the flat wire.

There may be hard solder between the flat wire and the pressed shaped strand. The brazing solder is preferably inserted between the shaped strand and the flat wire before compaction. The hard solder is z. B. during a diffusion welding process, the copper joining partner melts and wets the shaped strand and flat wire. This creates a significant improvement in the mechanical strength of the joint. An electrical conductivity of the braze, e.g. B. due to its silver component, can have a positive effect on the electrical conductivity of the connection between the flat wire and the shaped strand.

By integrating the copper strip and the brazing solder, the length of the compaction can be reduced while maintaining the mechanical strength requirements. This reduction is favorable for a low contact resistance. Potential electrical losses are therefore lower. This also results in a lower winding head height on the side of the laminated core on which the flat wires are located in the stator.

The flat wire can be welded to the shaped strand in advance using a diffusion welding process without any accessibility problems.

Isolation:

A wire enamel, preferably made of polyamideimide with insulation properties according to DIN EN 60317-26, is used to electrically insulate individual wires from each other. The individual wires are preferably made of copper or a copper alloy.

An advantageous individual wire can have a wire enamel layer thickness of 0.01 mm with a bare copper wire diameter of 0.71 mm. A wire enamel coating is also known as an overcoat. Optionally, an additional coating can be applied to the overcoat, which is referred to as a bonding coat or bond coat. A relatively heat-resistant material that is advantageous for coating is polyamide. The bonding coat can e.g. B. have a layer thickness of 0.0095 mm. A total diameter of the wire is therefore 0.749 ± 0.007 mm. All wire enamel has insulation class H.

A bonding coat can improve the stiffness of the shaped strand. For example, by heating the shaped strand, e.g. B. by means of current transmission, the individual wires can be connected or glued together.

Optionally, a baking varnish or bonding coat can be applied to the wire enamel of the individual wires. After being shaped into a coil, this can be thermally activated and bind the individual wires together. The rigidity of the shaped strand can be additionally increased by using a baking varnish, particularly in an area of the rod conductor. In addition, a baking varnish can further improve the dimensional stability of the shaped strand, especially in a transition area.

Optionally, additional electrical insulation can be applied in the areas of the compacted strand, in particular the areas of compaction, and/or the flat wire. For example, an insulating cover can be formed around the shaped strand or flat wire by wrapping it with self-adhesive insulation tape. This allows the requirement and thickness of the wire enamel in the area of the strand and flat wire to be reduced. With reduced wire enamel thickness, for example less than or equal to GRADE 1 (according to standard for wire enamel). cken: IEC 60317-0-1:2013 + AM01:2019), higher copper filling factors can be achieved and the performance of the electric machine can be further increased.

Extension shaping of the shaped strand:

The composite of shaped strands and two flat wires is moved from an almost linear extension (apart from a possible helix in the head area) to a U-shaped extension. The extension shaping takes place by bending the shaped strand. In the areas where there is a transition between two different cross sections of the shaped strand, the shaped strand is (or is) angled. The flat wires and the rod conductor areas of the shaped strand remain aligned with one another, preferably in an exactly linear manner. The flat wires are a straight continuation of the rod conductor areas of the shaped strand. The rod conductor areas in combination with the flat wires are aligned parallel to one another. The transition areas are (or are) angled towards each other like a roof. This first forming step can also be referred to as 2D forming. The U-shaped conductor or winding segments formed lie in one plane like hairpins. In addition, in particular subsequently, a second forming step takes place, which is also referred to as 3-D forming. During 3D forming, the transition areas of the shaped strand each experience a curvature, as a result of which the winding head lies outside the plane spanned by the rod conductors. With the help of this twist, a very compact coil head or winding head can be produced.

The head area, which is pre-formed helically between the transition areas, facilitates 3D forming. The individual wires within the strand can adapt or arrange themselves more effectively to an optimal transition path between the bar conductors before compression in the transition areas and in the bar conductor areas fixes their longitudinal arrangement to one another. Another advantage of the more effective arrangement is the reduced forming forces that can act on the individual wires. This reduces the risk of wire breaks and untwisting effects in the cross-sectionally shaped strand areas.

A compact coil head results in a smaller winding head. A small winding head reduces the necessary installation space that must be provided for an electric machine.

Shaping of the shaped stranded hairpin hybrid stator:

In a shaped strand hairpin hybrid stator, the coil or windings are formed from a so-called shaped strand hairpin hybrid. A shaped strand is used here, the shape of which is similar to a hairpin. The shaped strand preferably merges into solid conductive flat segments at its ends.

To automate the axial joining of the coils or conductor segments into the grooves of a laminated core, sufficient rigidity of the shaped strand is advantageous. The stiffness of the shaped strand is increased by compacting or pressing the strand. Depending on the joining concept and the intended assembly tolerances, a compacted shaped strand can already have sufficient rigidity.

If a typical length of a laminated core is assumed to be in a range of 80 mm to 200 mm, a rod conductor area of the shaped strand inserted into the laminated core preferably projects beyond the laminated core by a length in a range of 4 mm to 12 mm.

If the laminated core is equipped with conductor segments made from shaped stranded hairpin hybrids, the flat wires of the conductor segment are intertwined with each other. The entanglement is preferably carried out in a forming process that is applied to all flat conductors. Here, each first flat wire of a first conductor segment is bent towards the second flat wire of a second conductor segment assigned to it. This results in a spatial crossing of the flat wires in an isolated area of the flat wires. The uninsulated or stripped end regions of the two flat wires are preferably bent parallel to one another so that their contact surfaces lie on one another.

The flat wires, which belong to one another and are in particular already free of wire enamel at their ends, are preferably connected to one another in an electrically conductive manner by (laser) beam welding.

The flat wire is particularly advantageous for the entanglement process because it can be formed more easily and more consistently than a stranded wire. There is no risk of untwisting effects on the strand if the forming and twisting for the second winding head is carried out on flat wires.

Optionally, in the area of the first winding head, which is formed from compressed shaped strands, additional compression can be carried out, preferably in the fully assembled state of the conductor segments in the laminated core, e.g. B. using a pressure plate. This compression shortens the stator in an axial direction. With a conventional hairpin winding, which is made entirely of flat wire, one can Such compression can lead to contact problems, among other things, because considerably greater pressure forces have to be applied.

The typical height of the winding heads depends heavily on the sheet metal cut and the winding scheme. For a stator with an inner diameter of 120 mm whose laminated core has 60 slots, the first winding head for an ASM machine can have a height in a range of 30 mm to 55 mm. For a PSM machine, the winding head can have a height in a range of 15 mm to 45 mm. For the second winding head of an ASM machine, the height is in a range of 35 and 70 mm and for a PSM machine in a range of 20 mm to 60 mm.

Welding or soldering hairpin hybrid conductor segments:

Tests have shown that direct welding of strands without additional material is very difficult to implement. The wire enamel on the individual wires within the strand prevents sufficient quality for electrical contact and a low-porous formation of the contact surface. There is a great risk of contact resistance developing. Embrittlement, cracking and poor mechanical strength can also occur. In particular, an electrical connection of all individual wires often cannot be ensured in a reproducible manner. The outgassing effects of the wire enamel during the creation of the melt can result in very large ejecta and pores within the weld seam and lead to a defective bonding surface.

This can be circumvented by using diffusion welding processes (such as ultrasonic or resistance welding). However, due to their accessibility, these methods are certainly not suitable for connecting the conductor segments or their flat conductors in the installed state. Beam welding, usually laser steel welding, is preferred, especially in series production for larger quantities.

Stator design:

Hairpin machines are typically equipped with 4 to 10 layers of flat wires per slot to reduce AC losses.

Because shaped strand hairpin hybrid conductor segments have segmented individual conductors as cross-sectionally shaped strands within the groove, 2 layers per groove are sufficient to prevent these losses. Consequently, only 50% to 20% as many hairpin conductor segments need to be manufactured compared to known hairpin wires. This can also significantly reduce the number of welds required.

A further advantage results from the larger cross section of the shaped strand compared to a single flat conductor of a hairpin stator or a hairpin electric machine known from the prior art. The cross section of a shaped strand is approximately two to five times larger than that of known flat wire shark pins, which can result in a slightly higher rigidity for the shaped strand. Greater rigidity reduces the risk of failure when automating handling and joining operations in stator production.

In other words, ideally there should be exactly two shaped strands or rod conductors per slot. Due to the formation of the shaped strands from separate bundled and twisted individual conductors, additional rod conductors in a groove do not result in any further improvement in performance, in contrast to a known hairpin machine with several flat wires in a groove. An increase in the number of shaped strands or rod conductors per slot, e.g. B. three or four shaped stranded rod conductors per slot, but could be considered to implement a specific winding scheme.

An example of an electrical machine that can advantageously be equipped with a stator according to the invention is an asynchronous machine (ASM machine).

A stator for an ASM machine can e.g. B. ASM stator, 60 slots in the laminated core and 4 poles. It is a long configuration in which a line segment, which can also be referred to as a coil with a shaped strand, spans or jumps over 13 slots in the first winding head. The connecting web, which is present on the second winding head, skips or spans an average of 15 slots. Some of these connecting web jumps or spans include a larger number of grooves.

Another example of an electrical machine that can advantageously be equipped with a stator according to the invention is a permanently excited synchronous machine (PSM machine).

A stator for a PSM machine can e.g. B. have 48 grooves in the laminated core and 8 poles. It is an unsuspected configuration in which a coil in the first winding head jumps or spans 5 slots. In the second winding head, a connecting web also skips or spans an average of 5 slots.

In principle, stators according to the invention can also be provided with a different number of poles and a different number of slots in the laminated core. The groove that is spanned by a U-shaped strand or a number of grooves that is spanned by a connecting web can also be different - regardless of the dimensions of the laminated core.

Typical performance data of an electric machine or an electric motor that is equipped with a stator according to the invention are a peak power in a range of 100 kW to 450 kW (kilowatt), a peak torque in a range of 150 Nm to 650 Nm ( Newton meters), a continuous power in a range of 80 kW to 300 kW, a maximum speed in a range of 15,000 to 40,000 rpm (revolutions per minute) and an operating voltage in a range of 300 V to 850 V.

• • Herstellung einer verdichteten Litze mit unterschiedlichen Querschnittsformen. Damit wird eine Herstellung vergleichsweise kleinerer Wickelköpfe für Motoren einer vorgegebenen Leistungsklasse im Vergleich zu bekannten Motoren ermöglicht.
• • Kombination von Leitersegmenten mit verdichtetem Litzenmaterial und zwei lackisolierten Flachleitern. Die Konfiguration von Leitersegmenten ist effizient zur Befüllung eines Bestückungswerkzeugs vorproduzierbar. Mit dem Bestückungswerkzeug können alle Leitersegmente bzw. alle Stableiter gleichzeitig in die Nuten des Blechpakets in axialer Richtung eingeschoben werden.
• • Aufbau der Kompaktierung für die Verbindung von Formlitze und Flachdraht mit KupferBand und Hartlot zur Herstellung einer kompakten Fügeverbindung. Damit wird eine mechanisch beständige Verbindung ohne nennenswerten Kontaktwiderstand erzeugt.
• • Schräge am Flachleiter für die Herstellung der Kompaktierung. Damit wird sichergestellt, dass alle Einzelleiter nach der Kompaktierung noch durchgängig für elektrischen Strom sind.
• • Verwendung sehr dünner (= nicht Standard nach Norm) Drahtlackschichten auf dem Einzeldraht. Damit kann ein Kupferfüllfaktor in den Nuten erhöht werden. Falls erforderlich kann eine äußere Isolation des Leitersegments, insbesondere der Formlitze durch Isolationstape, erhöht werden.
• • Im Vergleich zu bekannten Anordnungen mit mehreren in eine Nut einzubringenden, dünnen, flachen Drähten bietet die Formlitze eine erhöhte Steifigkeit. Die Anzahl der Leiter pro Nut kann Dank der Verwendung von Formlitzen reduziert werden. Damit kann der Fertigungsprozess vereinfacht werden, der damit auch weniger fehleranfällig wird.
• • Konstruktiver Aufbau der Verschaltung ausgehend von axialem Fügen der Formlitze inkl. Flachdrähte in die Nuten; Kombination aus U-förmig gebogener Formlitze im ersten Wickelkopf und verschränkten Flachleitern im zweiten Wickelkopf. Es ergeben sich weitere fertigungstechnische Vorteile durch dieses Design.

Some of the features described also come with the following advantages:

• • Production of a compacted strand with different cross-sectional shapes. This makes it possible to produce comparatively smaller winding heads for motors of a given performance class compared to known motors.
• • Combination of conductor segments with compacted stranded material and two varnished flat conductors. The configuration of conductor segments can be efficiently pre-produced for filling an assembly tool. With the assembly tool, all conductor segments or all bar conductors can be inserted simultaneously into the grooves of the laminated core in the axial direction.
• • Construction of the compaction for the connection of shaped strands and flat wire with copper tape and brazing to create a compact joint connection. This creates a mechanically stable connection without significant contact resistance.
• • Slanted flat conductor for creating compaction. This ensures that all individual conductors are still capable of carrying electrical current after compaction.
• • Use of very thin (= not standard) wire enamel layers on the individual wire. This allows a copper filling factor in the grooves to be increased. If necessary, external insulation of the conductor segment, in particular of the shaped strand, can be increased using insulation tape.
• • Compared to known arrangements with several thin, flat wires to be inserted into a groove, the shaped strand offers increased rigidity. The number of conductors per slot can be reduced thanks to the use of shaped strands. This allows the manufacturing process to be simplified, making it less prone to errors.
• • Structural design of the wiring based on axial joining of the shaped strand including flat wires into the grooves; Combination of U-shaped shaped strand in the first winding head and interlaced flat conductors in the second winding head. There are further manufacturing advantages through this design.

The combinations and exemplary embodiments presented above can also be considered in numerous other connections and combinations.

For example, a rotor can be equipped with a shaped strand or an advantageous hybrid line segment. A stator can have two laminated cores, in each of which bar conductors are arranged as shaped strands and which are connected via connecting bridges or flat conductors.

Brief description of the characters

• 1 ein Beispiel für eine verdrillte Litze aus einem Bündel von Einzelleitern zeigt,
• 2 eine Verdichtung einer verdrillten Litze in einem Mittenbereich zeigt,
• 3 eine Formlitze, die entlang ihrer Längserstreckung verschiedene Querschnitte aufweist, zeigt,
• 4 ein Beispiel für eine trapezförmige Einzelleiteranordnung einer formgepressten Litze zeigt,
• 5 ein Beispiel für einen Flachdraht zeigt,
• 6 ein Leitungssegment aus einer Formlitze und zwei Flachdrähten zeigt,
• 7 schematisch einen Querschnitt durch ein Kompaktierungssegment einer Formlitze in einem Überlappbereich aus Formlitze und Flachdraht zeigt,
• 8 schematisch eine Querschnittansicht zeigt, die als rechtwinkliger Schnitt durch das Kompaktierungssegment und den Flachdraht von 7 gebildet ist,
• 9 eine Umwicklung eines Leitungssegments mit einem isolierenden Band zeigt,
• 10 ein als Hairpin geformtes Leitungssegment zeigt, das aus Flachdraht und Formlitze gebildet einen Hairpin-Hybrid darstellt,
• 11 eine Ansicht einer 3-D-Formgebung eines Hairpins nach 10 zeigt,
• 12 eine Einfügung von einem Leitungssegment in einen Kern eines Stators zeigt,
• 13 ein Beispiel für einen Stator im Aufbau zeigt, bei dem ein erster Wickelkopf an einer Seite des Kerns ausgebildet ist,
• 14 einen Querschnitt durch die Statoranordnung nach 13 zeigt,
• 15 einen Stator mit einem zweiten Wickelkopf im Aufbau zeigt, bei dem die Flachdrähte miteinander verschränkt sind und ein Laserstrahlschweißen stattfindet,
• 16 eine perspektivische Ansicht des aufgebauten Stators aus 15 zeigt,
• 17 zwei Anordnungsmöglichkeiten von Antriebssträngen in einem Kraftfahrzeug zeigt und
• 18 eine Abfolge verschiedener Verfahrensschritte bei der Herstellung einer elektrischen Maschine zeigt.

The present invention can be understood even better if reference is made to the accompanying figures, which exemplify particularly advantageous design options without restricting the present invention to them

• 1 shows an example of a twisted strand made from a bundle of individual conductors,
• 2 shows a compression of a twisted strand in a central area,
• 3 shows a shaped strand that has different cross sections along its longitudinal extent,
• 4 shows an example of a trapezoidal individual conductor arrangement of a compression-molded strand,
• 5 shows an example of a flat wire,
• 6 shows a line segment made of a shaped strand and two flat wires,
• 7 schematically shows a cross section through a compaction segment of a shaped strand in an overlap area made of shaped strand and flat wire,
• 8th schematically shows a cross-sectional view, which is a rectangular section through the compaction segment and the flat wire of 7 is formed,
• 9 shows a wrapping of a line segment with an insulating tape,
• 10 shows a line segment shaped as a hairpin, which represents a hairpin hybrid formed from flat wire and shaped strand,
• 11 a view of a 3D shape of a hairpin 10 shows,
• 12 shows an insertion of a line segment into a core of a stator,
• 13 shows an example of a stator in construction in which a first winding head is formed on one side of the core,
• 14 a cross section through the stator arrangement 13 shows,
• 15 shows a stator with a second winding head in the structure, in which the flat wires are intertwined and laser beam welding takes place,
• 16 a perspective view of the assembled stator 15 shows,
• 17 shows two possible arrangement options for drive trains in a motor vehicle and
• 18 shows a sequence of different process steps in the production of an electrical machine.

Character description

1 shows an example of a twisted strand 42, which is formed from a bundle of sixteen individual wires arranged next to one another, such as the individual wires 40, 40 ^I. The individual wires extend continuously from a first strand end 44 to a second strand end 46.

In 2 the twisted strand 42 is shown schematically with a straight strand extension 54. By forming a loop 80, a strand curvature 82 is added to the strand 42. Along the longitudinal extent of the strand 54, the loop 80 is shaped or pulled so tightly that a track offset 86 and a transverse extent 84 are formed which are larger than an original diameter of the linearly elongated strand (without reference numbers).

In the 3 Shaped strand 50 shown has a total length 56. The shaped strand 50 is equipped with seven segments over its total length 56, a first segment 91, a second segment 92, a third segment 93, a fourth segment 94, a fifth segment 95, a sixth segment 96 and a seventh segment 97. The strand segments 91, 92, 93, 95, 96, 97 usually have a substantially constant cross section over their entire length. A first strand cross section 105 is shown for the second segment 92. The third segment 93 has a second strand cross section 106. A third strand cross section 107 is present in the fourth segment 94. The fifth segment 95 has a fourth strand cross section 108. A fifth strand cross section 109 is formed along the sixth strand segment 96. The fourth strand segment 94 forms the central region 76 of the shaped strand 50. In the unpressed central region 76, the shaped strand 50 has an elongated, rounded shape according to the third strand cross section 107, which can also be referred to as an oval shape. A first transition segment 100 borders the central region 76 or the fourth strand segment 94 on one side and a second transition segment 101 on the opposite side. Both transition segments 100, 101 each have a strand cross section 106, 108, which has a rectangular cross-sectional shape 140, 142 . The rectangular cross-sectional shapes 140, 142 have the same height 124 and the same width 122. A first arm 60, which is designed as a first rod conductor 64, borders the first transition segment 100. The first rod conductor 64 has a first trapezoidal shape 130, which is shown on the first strand cross section 105. The first trapezoidal shape 130 has a first height 125 and a maximum width 123. The maximum width 123 merges into a smallest width 136 of the trapezoidal shape 130. A second arm 62 borders the second transition segment 101 as a sixth strand segment 96, on which a second Bar conductor 66 is formed. The shaped strand 50 has a second trapezoidal shape 132 as the fifth strand cross section 109 in the area of the second rod conductor 66. The second trapezoidal shape 132 has a second height 138. A largest width 137 of the second trapezoidal shape 132 is smaller than a largest width 123 of the first trapezoidal shape 130. The largest width 137 of the second trapezoidal shape 132 approximately corresponds to a smallest width 136 of the first trapezoidal shape 130. The height 125 of the first trapezoidal shape 130 is smaller than the height 138 of the second trapezoidal shape 132. First trapezoidal shape 130, first rectangular shape 140, second rectangular shape 142 and second trapezoidal shape 132 thus form a sequence of cross-sectional areas 128 of the shaped strand 50 along its total length 56. These cross-sectional shapes 128 are from a compression molding of the shaped strand 50 emerged. Both rod conductors 64, 66 are the same length. The rectangular shapes each have broad sides 141, 141 ^I , which are intended to rest on other broad sides. Depending on the position of the shaped strand 50, the height 124 of the rectangular shape 140 can also be referred to as the width 124 of the broad side 141. Correspondingly, the smaller width 122, which is located on a high side, such as the high side 143, can be referred to as a height 122 of the high side 143.

In 4 A trapezoidal shape 130 is shown, which, like all cross-sectional areas 128 (in 3 shown) is formed from the same twisted strand 42. There is therefore a constant cross-sectional area size 120, which is determined by all individual wires, such as the individual wire 40. The predetermined trapezoidal angle 134 of the first trapezoidal shape 130 determines the height of the trapezoidal shape 138 at a predetermined radial distance. In 1 It can also be seen that the individual wire 40, as well as the other individual wires (without reference numbers), have suffered a slight deformation of their originally round cross-sectional shape due to the pressing. This results in additional compression, which is greater for thicker individual wires than in exemplary embodiments in which a correspondingly larger number of thinner individual wires are used to form a shaped strand with the same cross-sectional area (not shown).

5 shows an example of a flat wire 180. The flat wire 180 has a flat wire height 189 and a flat wire length 188. An end region 200 of the flat wire 180 is for a compaction region of a shaped strand, such as the shaped strand 50 in 3 , beveled. That end region 200, like the opposite end region 206 of the flat wire 180, is free of wire enamel insulation 210. The wire enamel insulation 210 only extends between the end regions 200, 206 along the flat wire 280.

At the in 6 In the line segment 39 ^I shown, a shaped strand 50 ^I is connected on both sides to a first flat wire 181 and a second flat wire 182. The flat wires 181, 182 enclose a first line segment angle 59 and a second line segment angle 59 ^I with the shaped strand 50 ^I. A smallest width 136 ^I of the shaped strand 50 ^I transitions as smoothly as possible to a first width 190 of the first flat wire 181 in the first compaction segment 150, which overlaps an area 200 of the first flat wire 181. The first flat wire 181 has a flat wire end region 206, which also forms an end region of the line segment 39 ^I. An opposite end region 208 of the line segment 39 ^I is present on the second flat wire 182. A width 192 of the second flat wire 182 is larger than a width 190 of the first flat wire 181. The width 192 of the second flat wire 182 merges into a smallest width of a second trapezoidal shape 137 ', which is almost continuous starting from the shaped strand 50 ^I via a second compacting segment 152 is soldered to an end region 202 of the second flat wire 182. A first rod conductor 64 ^I formed on the shaped strand 50 ^I has a shorter length than a second rod conductor 66 ^I formed on the same shaped strand 50 ^I.

In 7 is the first compaction segment 150 after 6 drawn out in more detail. The shaped strand 50 ^I has a height 125 which is almost equal to a height 194 of the first flat wire 181. The height 194 of the first flat wire 181 includes an insulation layer 210, which is formed by a wire enamel. A first segment contact bevel 154 and a second segment contact bevel 154 ^I are incorporated into the flat wire end region 200. The segment contact bevels 154, 154 ^I have a (different) helix angle like the helix angle 155 of the first bevel 154. This means that the flat wire end area 200 is graded. A segment contact surface 153 extends between the segment contact bevels 154, 154 ^I , on which a hard solder 162 is arranged between the shaped strand 50 ^I and the first flat wire 181. In an overlap area 204 between the first flat wire 181 and the shaped strand 50 ^I , the flat wire 181 and the shaped strand 50 ^I are wrapped with a copper tape 158. The copper band 158 has a stabilizing effect, which is further enhanced by the fact that the copper band 158 is laid as an overlapping double layer 160 in the area of the shaped strand 50 ^I. The compaction segment has a predetermined compaction length 156, which is in particular greater than the height 125 of the shaped strand 50 ^I.

A cross section 157 out 7 is in 8th shown. The cross section 157 shows the overlap area 204 between the shaped strand 50 ^I and the first flat wire 181, surrounded by the copper strip 158 and the brazing solder 162 as an intermediate layer. The shaped strand 50 ^I and the second flat wire 182 are in the same way as in 7 and 8th for the first flat wire 181 is shown connected to each other.

Out of 9 It can be seen that a line segment 39 whose individual wire insulation of the shaped strand 50 is not considered sufficient can also be wrapped with an insulating tape 166. The insulating tape 166 can cover the entire formed strand 50 including compaction segments, such as the first compaction segment 150. The flat wire 181 is equipped with wire enamel insulation 210, of which only the flat wire end area 206 is free.

A line segment 39 is in 10 shown in a U-like shape curved to form a hairpin 70. In a shaped strand head area 78, the first transition segment 100 and the second transition segment 101 of the shaped strand 50 are angled towards one another. A strand bend 58 is present between the first transition segment 100 and the first rod conductor 64. The first rod conductor 64 has a rod conductor length 68. The rod conductor length 68 of the first rod conductor 64 is equal to the rod conductor length 69 of the second rod conductor 66. The second rod conductor 66 continues the second transition segment 101 at a second strand bend 58 ^I. The first bar conductor 64 and the second bar conductor 66 extend parallel to each other. A first end region 72 of the shaped strand 50 lies laterally opposite an end region 200 of the first flat wire 181 and is connected to it in a metal-fitting manner. The first end region 72 of the shaped strand 50 is compacted for (or during) the production of the connection with the first flat wire 181. Corresponding to the first end region 72 of the shaped strand 50, a second end region 74 of the shaped strand 50 is also compacted and connected to an end region 202 of the second flat wire 182 in a metal-fitting manner. The line segment 39 is therefore an electrically continuous composite of a shaped strand 50 and two flat wires 181, 182. There are flat wire end regions 206, 208 on the flat wires 181, 182, which at the same time form the insulator-free end regions of the line segment 39. The transition segments 100, 101 and the rod conductors 64, 66 lie in (or on) a shaped strand plane 48.

Will start from 10 a viewing direction of the line segment 39 towards the shaped strand head area 78, ie chosen along the lengths 68, 69 of the rod conductors 64, 66, results in the view of the line segment 39 from 11 .

In 11 From the line segment 39 in the selected view, the first transition segment 100 can be seen, from which the shaped strand 50 (see 10 ) leads to the second transition segment 101 via the shaped strand head area 78, which is designed as a kind of joint point. The two transition segments 100, 101 extend with a first track offset 86. In the selected representation of the hairpin 70 11 Because of the strand bends 58, 58 ^I, the bar conductors and flat wires of the hairpin 70 are out 10 not visible. In the 10 or. 11 Hairpin 70 shown is the result of a 2-D forming 1060. In a 3-D forming 1070, the line segment 39 or its shaped strand is formed into an enlarged track offset 86 ^I. During the forming, in addition to the central region 78, the first transition segment 100 is given a third curvature 58" and the second transition segment 101 is given a fourth curvature 58 ^III . In particular, the rod conductors (see rod conductors 64, 66 in 10 ) twisted into a position suitable for insertion into the core. Reference is made to the form strand level 48 of 10 taken, the rod conductors 64, 66 are in accordance with 1070 after the 3-D forming 11 still in that level 48, but the transition segments 100, 102 lead out of the shaped strand or rod conductor level 48.

According to 12 The line segment 39 is inserted in a longitudinal or axial direction 24 along a rotor axis 22. The rotor axis 22 extends centrally through the core 4. The core 4 or the laminated core 4 has a fixed length 6. The line segment 39 is inserted along the rotor axis 22 simultaneously into a first inlet opening 16 and into a second inlet opening 18. The line segment is inserted with its flat wires 181, 182 first until only the shaped strand head area 78 stands out from the line segment 39 above the laminated core 4, as can be seen from a second line segment 39". The shaped strand 50" projects beyond the length of the core 6. The second line segment 39" is already inserted into the core 4, so that its shaped strand 50" is already in the core 4 and its flat wires 181 ^I , 182 ^I from the core 4 or the outlet openings belonging to the inlet openings 16, 18 19, 19 ^I stand out.

If the core 4 is completely equipped with conductor segments, such as the conductor segment 39, the view of a stator 2 results 13 . On a first side 32 of the core 4, a first winding head 37 is formed, on which shaped strand head areas, such as a first shaped strand head area 78 and a second shaped strand head area 78 ^I , form a spatial closure. A first group of flat wires 220 and a second group of flat wires 222 extend from a second side 34 of the core 4, which serve to form a second winding head 38. The jacket 30 of the core 4 is therefore located between the first winding head 37 and the second winding head 38. The flat wires of the first group 220 each have a first height 194 and the flat wires of the second group 222 each have a second height 196. The second height 196 is greater than the first height 194. A cross section 29 through the core 4 equipped with line segments, such as the line segment 39 13 is in 14 shown.

According to 14 Gaps, such as the gap 20, which are embedded in a rotor-side core inner wall 31, lead into core grooves, such as the first core groove 8 and the second core groove 10. 14 shows a section through all the trapezoidal rod conductors inserted into the core 4, such as the rod conductors 64, 66. A single shaped strand extends, for example, according to 13 connected in the first winding head 37, from a first radial region 12, an inner radial region 12 of the first core slot 8 to a second radial region 14, an outer radial region 14 of the second core slot 10. In a single slot, such as the slot 8 and the slot 10, are inner bar conductors, such as the bar conductor 64, packed tightly together with outer bar conductors, such as the bar conductor 66. In a core groove, such as the core groove 10, there are two different shaped strands, such as the shaped strands 50, 50 ^II , arranged. A first shaped strand 50 is inserted with its rod conductor 64 in the first groove 8 radially close to the inner wall 31. A second shaped strand 50 ^II is inserted in the second groove 10 radially away from the inner wall 31. In addition, another shaped strand 50 ^III is inserted radially in the second groove 10 near the inner wall. This means that the second groove 10 is well filled.

At the in 15 Stator 2 shown in an advanced stage of production are based on the arrangement of the stator 2 in 13 The web interconnections 170 are formed in the second winding head 38. Arranged next to each other are several interconnection webs, such as the interconnection webs 172, 174, each of which has a metal connection 232 on a contact surface 276 made by laser beam welding 230.

16 shows a perspective view of the completed stator 2, in which a winding through the core 4 from the first winding head 37, which sits on the first end face 26, to the second winding head 38, which is arranged on the second end face 28, through the core 4 runs through. The windings 36 extend, in other words, from the first winding head 37 to the second winding head 38 and from the second winding head 38 to the first winding head 37. The second winding head has a plurality of interconnection web sections 272, 272 ^I , 274, 274 ^I. On all Y configurations such as the Y configuration 270, a first interconnection web section 272 and a second interconnection web section 274 are welded together in the area of their contact points, such as the contact point 278. Due to the interlacing of all interconnection web sections, such as the interconnection web sections 272, 272 ^I , 274, 274 ^I of the second winding head 38, interconnection web sections, such as a rear interconnection web section 272 ^I and a front interconnection web section 274, cross over A common groove (not visible) connecting web sections 272 ^I , 274 ^I for all grooves are bent in opposite directions. The bending took place by way of the entanglement process for the formation of the winding(s). A contacting strand 256 leads from one winding end 250 to a plug connector 260, which enables an electrical connection to an inverter (not shown).

In 17 A motor vehicle 500 is shown schematically, which is equipped with four wheels 551, 552, 553, 554. Two wheels 551, 552 are steerable. The wheels 551, 552 are connected to a first drive train 502. The drive train 502 on the front axle 504 includes a torque transmission device 510. The torque transmission device includes a transmission 512. Drive shafts, such as the drive shaft 514, transmit torque to the road wheels 551, 552. The transmission 512 and an electric machine 530 are arranged in an overall housing 520. The electrical machine 530 includes a stator 2. The stator 2 is attached to the overall housing 520. There is a rotor 540 in the stator 2, from which the gear 512 can be driven. The first winding head 37 of the stator 2 is positioned in the vicinity of the gear 512. Due to the lower height of the first winding head 37 compared to the second winding head 38, the laminated core of the stator 2, in which the rotor 540 sits, sits particularly close to the transmission. This enables a particularly low lateral force coupling of the electric machine 530 to the transmission 512.

A second example of a drive train 502 ^I is arranged on the rear axle 506 of the motor vehicle 500 and is used to drive two rear road wheels 553, 554. A first electric machine ^{530 I ,} which has a first stator 2 ^I , sits in an overall housing 520 I. and a second electric machine 530 ^II having a second stator 2 ^II . Both electric machines 530 ^I , 530 ^II can each supply a torque to a transmission 512 ^I in order to drive two road wheels 553, 554 via a torque transmission device 510 ^I. All electric machines 530, 530 ^I , 530 ^II are equipped with a suitable power supply, e.g. B. connected via an inverter (not shown) for an electric machine.

In an advantageous method 1002, depending on which step the method is processed up to, the production of a line segment, a stator or an electric machine can take place. As a starting point, insulated copper wire 1004 is provided. A predetermined number of individual wires are cut to length and twisted into a strand 1006. Instead of twisting, depending on the preferred embodiment, one can also speak of twisting or stranding. By running 1076 in parallel, a large number of stranded wires can be used (cf. stranded wire acc. 1 ) are manufactured and further processed. The stranded wires are formed to form a coil head 1010. The forming takes place by twisting the stranded wire in a loop-like loop (cf. 2 ). This is followed by a compression of the respective strand into different cross-sectional segments 1020 (cf. 4 ). Compression can also involve forming, e.g. B. done by pressing and compacting. In addition, a number of flat wire pieces twice the number of strands is provided 1030 and each flat wire piece undergoes a final revision Reichs to equip the piece of flat wire with a bevel at the end 1034 (cf. 7 ) and remove any wire enamel present at the end area. In a subsequent step 1040, each shaped strand is welded or soldered to two pieces of flat wire, one flat wire at each end of the shaped strand - depending on the preferred embodiment (cf. 6 ). Due to the parallel execution 1076, there is a predetermined number of line segments. Optionally, an insulation tape 1050 can be provided and the line segment can be wrapped with the insulation tape 1052 (cf. 9 ). The line segment is then formed into a U-shape 1060 (cf. 10 ), which is a 2-D shape. In a subsequent step 1070, the line segment is angled or rounded to form a 3-D shape, whereby the line segment becomes a coil segment (cf. 11 ). These forming steps are e.g. B can be carried out by bending, free forming or die forming - depending on the preferred procedure. Due to the parallel design 1076, there is a predetermined number of coil segments. In a subsequent step 1080, a laminated core is provided, into which the coil segments are inserted in an axial direction into the groove of the laminated core for forming the coil winding 1090 (cf. 12 as well as 14 ). This is followed by interlacing the flat wires 1100 protruding from the laminated core (cf. 13 as well as 15 ). The entanglement occurs through a deformation, such as bending. The interlaced flat wires are then welded together in their free end areas 1110 (cf. 15 ). Welding can e.g. B. can be carried out using beam welding, laser beam welding, electron beam welding or TIG welding. There is now a first winding head and a second winding head on the laminated core, which can optionally be compacted more strongly by applying an axial force 1120. Connecting lines 1140 are provided one after the other to the created stator (cf. 16 ) and insulation means 1150 provided. In a further processing step 1160, the connecting lines are first welded to the windings of the stator (or soldered, preferably in the same way as the previously described connection between a flat wire and a shaped strand). A subsequent casting of the windings with an insulating agent can optionally be carried out or omitted. Additionally, the stator can be treated by impregnation or whirl sintering to prepare the stator for demanding environmental conditions. This is usually followed by an EOL (End-Of-Line) function and quality control of the production of the stator. In a further step 1190, an electric machine is produced (cf. 18 ) the produced stator is combined with a provided rotor 1180 for final assembly.

The design options shown in the individual figures can also be combined with one another in any form. If, for example, one speaks of a first segment 91, a second segment 92, a third segment 93, etc., such a numbering, in particular a continuous numbering, can be interchanged without deviating from the object described.

Reference symbol list

2, 2I, 2II

stator

4

Core, especially laminated core

6

Length of the core, in particular length of the laminated core

8th

first core groove

10

second core groove

12

first radial area

14

second radial area

16

first inlet opening, in particular first groove entrance

18

second inlet opening, in particular second groove entrance

19, 19I

Exit opening, especially groove exit

20

gap

22

Rotor axis, like an axis of rotation through the stator

24

Longitudinal direction

26

first face

28

second face

29

Stator cross section

30

Lateral surface, like an outer jacket

31

Core inner wall, in particular the rotor-side inner wall of a laminated core,

32

first side of the core

34

second side of the core

36

Winding, especially winding area

37

first winding head

38

second winding head

39, 39I, 39II

line segment

40, 40I

Single wire, especially enameled stranded wire

42

twisted strand

44

first strand end

46

second strand end

48

Formed strand level, especially rod conductor level

50, 50I, 50II,50III

Formed strand, in particular first formed strand

52

Formed strand, in particular second formed strand

54

Strand longitudinal extension

56

Total length of the shaped strand

58, 58I, 58II,58III

Strand bending

59, 59I

Line segment angle

60

first arm

62

second arm

64, 64I

first staff leader

66, 66I

second staff leader

68

Length of the first rod conductor

69

Length of the second rod conductor

70

Hairpin

72

first end region of a shaped strand

74

second end region of a shaped strand

76

Middle area of a shaped strand

78, 78I

Shaped strand head area, in particular the area in the middle between the arms of a shaped strand, in which shaped stranded head segments are located

80

Loop forming

82

Curvature, especially strand curvature

84

Transverse extension

86, 86I

Track offset

91

first strand segment, like a first area of a shaped strand

92

second strand segment, like a second area of a shaped strand

93

third strand segment, such as a third area of a shaped strand, in particular shaped strand head segment

94

fourth strand segment, such as a fourth region of a shaped strand, in particular shaped strand head segment, like a third shaped strand head segment

95

fifth strand segment, such as a fifth area of a shaped strand, in particular shaped strand head segment

96

sixth strand segment, like a sixth area of a shaped strand

97

seventh strand segment, like a seventh area of a shaped strand

100

first transition segment, in particular first shaped strand head segment

101

second transition segment, in particular first shaped strand head segment

105

first strand cross section

106

second strand cross section

107

third strand cross section

108

fourth strand cross section

109

fifth strand cross section

120

Strand cross-sectional area size

122

first width of the shaped strand, especially the height of the high side

123

second width of the shaped strand, in particular maximum width of a first trapezoidal shape

124

Height of the shaped strand, especially width of a broad side

125

Height of the shaped strand, in particular the height of the first trapezoidal shape

128

Sequence of different cross-sectional areas

130

first bar ladder shape, in particular first trapezoidal shape

132

second bar ladder shape, in particular second trapezoidal shape

134

Trapezoid angle

136, 136I

smallest width of a first trapezoid shape

137

largest width of a second trapezoid shape

137I

smallest width of a second trapezoid shape

138

Height of a second trapezoid shape

139

Height of the first trapezoid shape

140

rectangular strand cross-section, in particular first rectangular cross-sectional shape

141, 141'

first broadside

142

rectangular strand cross-section, in particular second rectangular cross-sectional shape

143

High side

150

first compaction segment

152

second compaction segment

153

Contact point, especially segment contact surface

154, 154I

Segment contact bevel

155

Draft angle

156

Compaction length

157

Cross section of the compaction segment

158

Copper foil, especially copper tape

160

Copper tape overlap, especially copper tape double layer

162

Hard solder

166

Insulator layer, especially insulating fabric tape

168

electrical connection

170

Bridge connection

172

first interconnection bridge, in particular first interconnection bridge

174

second interconnection bridge, in particular second interconnection bridge

180

Flat wire

181, 181I

first interconnection web section, in particular first flat wire

182, 182I

second interconnection web section, in particular second flat wire

188

Flat wire length

189

Flat wire height

190

first width, in particular width of a first flat wire

192

second width, in particular width of a second flat wire

194

first height, in particular height of a first flat wire

196

second height, in particular height of a second flat wire

200

End region of the first flat wire, in particular a beveled flat wire end for compaction

202

End region of the second flat wire, in particular a beveled flat wire end for compaction

204

Overlap area

206

Flat wire end area of a first flat wire, in particular insulator-free area

208

Flat wire end area of a second flat wire, in particular insulator-free area

210

Wire enamel insulation, especially wire enamel layer

220

first group of flat wires

222

second group of flat wires

230

Beam welding, especially laser beam welding

232

metallically coherent connection

250

winding end

256

Connectors

260

Contacting wire

270

Y configuration

272, 272'

first interconnection web section of a first line segment

274, 274I

second interconnection web section of a second line segment

276

Contact surface, especially broadside contact surface

278

Contact point, in particular cohesive connection

500

motor vehicle

502

Drivetrain

504

Front axle

506

rear axle

510, 510I

Torque transmission device

512, 512I

transmission

514

drive shaft

520, 520I

Overall housing

530, 530I, 530II

electric machine

540

rotor

551

first road bike

552

second road bike

553

third road bike

554

fourth road bike

1002

Method for producing a stator and an electric machine

1004

Provision of insulated copper wire

1006

Cutting and twisting individual wires into strands

1010

Forming the strand to form a head area of a shaped strand

1020

Compression of the shaped strand in areas with different cross sections

1030

Provide two pieces of flat wire stripped at their ends

1034

Forming an end portion on each piece of flat wire with a bevel

1040

Welding or soldering a shaped flat wire end area to a shaped strand end area in a compressed overlap area

1050

optional provision of an isolation tape

1052

optional wrapping of the shaped strand with an insulation tape

1060

Bending the shaped strand into a U-shape (2-D forming)

1070

Bending the shaped strand into a line segment shape or coil segment shape (3D forming)

1076

carrying out the production of the line segments for a stator in parallel

1080

Provision of a laminated core equipped with grooves for mounting a stator

1090

Insert all line segments into the grooves of the laminated core in the axial direction

1100

Intertwining the flat wires by bringing together wiring web sections

1110

Welding the flat wires in pairs at their free ends or end areas

1120

optional compaction of a winding head

1140

Provision of winding connection cables

1150

Provision of insulation and/or grouting materials

1160

Contacting and enclosing the winding heads

1180

optional provision of a rotor

1190

Optional assembly of stator and rotor to form an electric machine

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

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• DE 102011000172 A1 [0007]
• DE 102021123019 A1 [0008]
• DE 102016123067 A1 [0009]
• DE 102007021321 A1 [0010]
• DE 112019006919 T5 [0011]
• US 9419491 B2 [0011]
• DE 102014214066 A1 [0012]
• EP 3512075 B1 [0013]
• US 6353198 B1 [0014]
• WO 2020/092570 A1 [0015]
• DE 102020130647 A1 [0015]
• US 2012/0212088 A1 [0017]
• DE 102004050824 A1 [0018]
• WO 2015/162586 A2 [0019]
• EP 3051669 B1 [0019]
• EP 2991199 A1 [0020]
• DE 102018131965 A1 [0021]
• DE 102017125887 A1 [0021]
• DE 102018208407 A1 [0021]
• DE 102018131960 A1 [0021]
• DE 102018218732 A1 [0021]
• WO 2021/250259 A1 [0022]
• US 2021/0006115 A1 [0025]
• DE 102005025217 A1 [0026]
• DE 60306850 T2 [0027]
• DE 102018101231 A1 [0028]

Claims (15)

Method for producing a line segment (39, 39 ^I , 39 ^II ) as part of a winding (36) of an electrical machine (530, 530 ^I , 530 ^II ), wherein a stranded wire (42), consisting of several individually insulated and twisted stranded wires ( 40, 40 ^I , 1006) along their longitudinal extension (54), and two pieces of flat wire (180, 181, 181 ^I , 182, 182 ^I , 220, 222) are provided (1030) and in a first area (94). The strand (42) is formed (1010) with a strand curvature (82), characterized in that the first region (94) is a central region (76) along the longitudinal extent of the formed strand (54), and that the strand (42) has a cross-sectional shape in some areas the strand (42) is subjected to compression molding (1020), whereby a shaped strand (50, 50 ^I , 50 ^II , 50 ^III ) is created, which in a second area and in a third area (92, 96) of its longitudinal extension (54) each in a rod conductor form (130, 132), the second region (92) and the third region (96) each being a rod conductor (64, 64 ^I , 66, 66 ^I ) of the line segment (39, 39 ^I , 39") can be inserted into a stator (2, 2 ^I , 2 ^II ) of the electrical machine (530, 530 ^I , 530"), and the shaped strand (42) with its longitudinal extension (54) in two end regions (72, 74). an insulator-free end (200, 202) of one of the two flat wires (180, 181, 181 ^I , 182, 182 ^I , 220, 222) is brought (1040) into an overlap area (204) and pressed, the overlap area (204) is formed by the end (200, 202) of the respective flat wire (180, 181, 181 ', 182, 182 ^I , 220, 222) and one of the end regions (72, 74) of the strand (42) in order to form a metallically coherent Connection to be spent (1040). Method for producing a line segment (39, 39 ^I , 39") Claim 1 , characterized in that the strand (42) is compressed by compression molding (1020) into the bar conductor shape (130, 132) in a linearly extending area for insertion (1090) into the electrical machine (530, 530 ^I , 530") . Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the strand (50, 50 ^I , 50 ^II , 50 ^III ) has at least three strand segments (91, 92, 93, 94, 95, 96, 97), preferably at least seven strand segments (91, 92, 93, 94, 95, 96, 97). Method for producing a line segment (39, 39 ^I , 39") Claim 3 , characterized in that two strand segments (93, 95), which preferably have the same length, are designed with the same strand cross section (106, 108). Method for producing a line segment (39, 39 ^I , 39 ^II ) according to one of the preceding claims, characterized in that the strand (42) is not subjected to any cross-section-determining compression molding in the area of the strand curvature (82). Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the strand curvature (82) is formed by a loop formation (80). Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the rod conductors (64, 64 ^I , 66, 66 ^I ) are positioned relative to one another by bending the strand (42) in the area the strand curvature (82). Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that at least two transition segments (94, 100, 101) are formed in the central region (76), the two transition segments (100 , 101) are each pressed into a rectangular cross-sectional shape (140, 142), which is uniform in particular along a length of the respective transition segment (100, 101). Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the rod conductors (64, 64 ^I , 66, 66 ^I ) have the same length, the length being in particular based on a longitudinal extent Core (4), such as a laminated core (4), of the stator (2) is coordinated along a rotor axis. Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the stranded wires (40, 40 ^I ) of the strand provided (42) extend along the longitudinal extension of the shaped strand (54) from a first strand end ( 44) extend continuously to a second strand end (46). Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that a twist of the individual wires (40, 40 ^I ) amounts to an integer multiple of a lay length. Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the rod conductors (64, 64 ^I , 66, 66 ^I ) of the shaped strand (50) are formed into a first rod conductor shape with a cross-sectional area, which represents a first trapezoidal shape (130), and are formed into a second bar conductor shape with a cross-sectional area which represents a second trapezoidal shape (132), in particular the first and second trapezoidal shapes (130, 132) having the same trapezoidal angle (134) are formed and preferably a smallest width (136, 136 ^I ) of the first trapezoidal shape (130) and a largest width (137) of the second trapezoidal shape (132) approximately match. Method for producing a line segment (39, 39 ^I , 39") according to one of the preceding claims, characterized in that the metallically coherent connection is made electrically conductive by soldering or welding or laser beam welding (230) or crimping. Method (2002) for producing a stator (2) of an electrical machine (530, 530 ^I , 530 ^II ), characterized in that the method (2002) has the following steps: - parallel execution (1076) of a production of a plurality of line segments ( 39, 39 ^I , 39") according to one of the preceding claims, each of which has a shaped strand (50, 50 ^I , 50 ^II , 50 ^III , 52) and two flat wires (181, 181 ', 182, 182'), - provision (1080) of a laminated core (4) equipped with grooves (8, 10) for mounting the stator (2), - inserting (1090) all line segments (39, 39 ^I , 39") into the grooves (8, 10) of the laminated core (4) in the longitudinal direction of the laminated core (4) with the flat wires (181, 181', 182, 182') in front, - interlocking (1100) of the flat wires (181, 181 ^I , 182, 182') of the line segments ( ^{39 _ _} , 202), - compaction (1120) of a winding head (37, 38) formed on the laminated core (4) by the line segments (39, 39 ^I , 39"). Drive train (502) for a motor vehicle (500), which has an electric machine (530, 530 ^I , 530 ^II ) for generating a drive torque of the electric machine (530, 530 ^I , 530") with a rotor (540) and with a stator (2, 2 ^I , 2 ^II ) and a torque transmission device (510, 510 ^I ) connected to the electric machine (530, 530 ^I , 530 ^II ), through which a torque is transmitted to at least one road wheel (551, 552, 553, 554). of the motor vehicle (500), the stator (2, 2', 2") of the electrical machine (530, 530 ^I , 530") having a core (4) with core grooves (8, 10) for line segments (39, 39 ^I , 39"), characterized in that the stator (2, 2 ', 2") according to a method (2002) according to Claim 14 is formed or in the stator (2, 2 ', 2 ^II ) line segments (39, 39 ^I , 39"), which with a method according to one of Claims 1 until 13 have been manufactured, used and electrically conductively connected to the flat wires (180, 181, 181 ^I , 182, 182 ') to form a winding (36).

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