Stator for an electric machine having a clamp-fixed conductor end section and electric machine

Abstract

A stator includes a stator body having a plurality of radially oriented single teeth; the multi-phase stator winding is provided with a plurality of single-tooth coils formed by winding wires, and one single-tooth coil is arranged at each single tooth; a plurality of winding bodies, each of which has a winding region for the single-tooth coil, said winding region being formed by a base section and two delimiting sections; the invention relates to a connection ring assembly for connecting to a single-tooth coil, which is fastened to a plurality of winding bodies on the axial end side of the stator and has a support section for supporting the connection ring assembly in the radial direction on at least one delimiting section and a plurality of winding terminal connecting pieces for connecting to the single-tooth coil, at least one wire end section of each winding wire is bonded to the associated winding terminal connection piece on the end side with its free wire end at a bonding point in a cohesive manner, and the wire end section is clamped and fixed between one of the limiting sections and the corresponding support section at each clamping point. In this way, the free wire length of the wire end section is shortened.

Description

Technical Field

[0001] The invention relates to a stator for an electric machine having the features of the preamble of claim 1. The invention also relates to an electric machine having such a stator. Background Art

[0002] A stator for an electric motor is known, which has radially oriented stator teeth, wherein the stator winding is formed by individual stator coils (also referred to as single-tooth coils) wound around the stator teeth. The stator coils each have two coil ends, which are connected in a predetermined manner via a wiring unit. For this purpose, the wiring unit has a terminal connection piece for each single-tooth coil, via which the two single-tooth coils are welded and connected.

[0003] Patent document DE 10 2019 218 442 A1 discloses a stator of an electric motor, which has a laminated core constructed in an annular manner around a central axis, and a stator coil having coil ends is arranged on the laminated core by means of a winding body; and the stator has a wiring device, which has a plurality of mutually insulated connecting conductors, and the connecting conductors have a coil connection area for wiring the stator coil, wherein the wiring device is engaged with the stator coil in an axial joining direction and is arranged adjacent to the stator coil, and is fixed to the winding body by means of an axial connecting device to form a plurality of axial connections, wherein the wiring device has a radial supporting device for cooperating with the winding body, which is constructed independently of the axial connecting device. Summary of the invention

[0004] The object of the invention is to provide a stator of the type mentioned at the outset which is characterized by high operational reliability.

[0005] This object is achieved by a stator having the features of claim 1 and by an electric machine having the features of claim 15. Further features, advantages and effects of the invention are described in the dependent claims, the description and the drawings.

[0006] The subject of the invention is a stator designed for an electric machine and / or suitable for an electric machine. In particular, the electric machine is designed as an inner rotor electric machine, wherein the rotor is arranged radially inside the stator. However, the electric machine can also alternatively be designed as an outer rotor electric machine, wherein the rotor is arranged radially outside the stator.

[0007] The stator has a stator body which is constructed around a main axis and has a plurality of radially oriented single teeth. In principle, the stator body can be formed from a plurality of segments of similar type, each segment having at least one or exactly one single tooth. The individual segments are preferably connected to one another so that they form an in particular annular and / or cylindrical stator. Alternatively, the stator body has an annular stator yoke at which the single teeth are constructed. By way of example, the stator body can be constructed as a laminated core.

[0008] The stator has a multi-phase stator winding having a plurality of single-tooth coils formed by winding wires, wherein a single-tooth coil is arranged at each single tooth. In other words, the stator winding is configured as a concentrated winding in the form of single-tooth coils. In particular, the single teeth are each individually wound by a winding wire. As an example, the winding wire is configured as a round wire.

[0009] The stator has a plurality of winding bodies, wherein the winding bodies each have a winding region for a single-tooth coil or a winding conductor, the winding region being formed by a base section located at the end side of one of the single teeth and two delimiting sections radially delimiting the winding region and connected to the base section. Preferably, the stator has two winding bodies for each single tooth, wherein the two winding bodies are arranged on the end sides of the single tooth facing away from each other. The winding conductor is respectively wound around the respective single tooth via at least one, preferably two winding bodies in the winding region and is fixed there to prevent slipping. In particular, the end-side winding heads of the single-tooth coil are respectively arranged in the winding region of the winding body or are formed by it. As an example, the winding body is made of a heat-resistant and / or electrically insulating plastic.

[0010] In addition, the stator has a terminal ring assembly, which is configured and / or suitable for wiring a single-tooth coil, wherein the terminal ring assembly is fixed to a plurality of winding bodies at the axial end side of the stator. The single-tooth coils are connected to each other via the terminal ring assembly, for example in a delta connection or a star connection. The terminal ring assembly preferably has a power connection portion, via which the motor can be connected to the power electronics. The terminal ring assembly is preferably coaxially and / or concentrically engaged with the stator coil in an axial engagement direction on the stator and is arranged adjacent to the single-tooth coil, preferably adjacent to the winding head. Particularly preferably, the terminal ring assembly is fixed to a plurality of winding bodies via a plurality of axial connections.

[0011] The terminal ring assembly has at least one or exactly one supporting section facing the winding area, through which the terminal ring assembly is supported in the radial direction relative to the main axis and / or can be supported at at least one or exactly one limiting section to form a radial connection. In particular, the supporting section is used to center and fix the terminal ring assembly in a defined radial position. The radial connection is preferably produced by a form-fitting connection in the radial direction. The supporting section can act on one side or both sides in the radial direction. To this end, the supporting section can act on one or two limiting sections of the winding body on the radial inside and / or radial outside, respectively. Particularly preferably, the supporting section is supported on the radial inside of the winding area and / or can be supported at one of the limiting sections. The supporting sections can be constructed, for example, as continuous or discontinuous protrusions in the circumferential direction, respectively.

[0012] The wiring ring assembly has a plurality of winding terminal connection pieces, which are configured and / or suitable for connection with a single-tooth coil. In particular, each single-tooth coil is assigned at least one or exactly one winding terminal connection piece. The winding terminal connection pieces are preferably arranged at the radial outer side of the wiring ring assembly. However, the winding terminal connection pieces can also be arranged at the radial inner side of the wiring ring assembly instead. As an example, the winding terminal connection pieces are respectively configured as terminal connection pieces that are angled and / or oriented in the same manner as the axial direction.

[0013] The winding wires of the single-tooth coil each have at least one or exactly one, preferably exactly two wire end sections, which are joined to the associated winding terminal connecting piece at the joining position with free wire ends on the end side in a materially connected manner. In particular, at least one, preferably two wire end sections are arranged on one side or both sides of the winding terminal connecting piece. In other words, each winding terminal connecting piece is arranged in the circumferential direction between two wire end sections, more precisely, their free wire ends. As an example, the free wire ends can be welded or soldered to the corresponding winding terminal connecting piece. In particular, the geometry of the winding terminal connecting piece can be provided with a widening portion toward the joining position in order to eliminate or at least reduce the joining gap at the joining position between the wire end section and the winding terminal connecting piece.

[0014] In the scope of the present invention, the wire end section is clamped and fixed between one of the delimiting sections and the corresponding supporting section at each clamping location in order to shorten the free wire length of the wire end section. Preferably, when the winding terminal connecting piece is arranged at the radial outside, the clamping location is arranged at the radial outside, and when the winding terminal connecting piece is arranged at the radial inside, the clamping location is arranged at the radial inside. In other words, clamping is optionally performed between the delimiting section and the supporting section located at the radial outside or between the delimiting section and the supporting section located at the radial inside. For this purpose, a clamping force is preferably applied to the wire end section in the axial direction relative to the axis of rotation. As an example, the clamping force can be applied and maintained during the establishment of the axial connection.

[0015] The present invention is based on the recognition that the terminal ring assembly is excited to vibrate during the operation of the electric machine and / or during the operation of a vehicle equipped with the electric machine, such as a hybrid vehicle, due to the direct connection to the stator. Due to the unsupported wire end section from the winding around the single tooth to the joint at the winding terminal connecting piece, the natural frequency of the wire end section is in the operating frequency range of the vehicle's electric machine and / or internal combustion engine. Therefore, the wire end section is subjected to high-frequency mechanical alternating loads, which may lead to vibration fatigue fracture of the wire end at the joint and thus to wire fracture. The advantage of the present invention is that by clamping the wire end section, the free wire length can be shortened, thereby moving the natural vibration of the wire end section out of the operating frequency range. As a result, the risk of wire fracture can be significantly reduced or eliminated in a simple and cost-effective manner, thereby preventing motor failure and improving operational reliability.

[0016] In a specific embodiment, it is provided that the free line length of the line end section is shortened to such an extent that the natural frequency of the line end section is shifted outside the frequency range of the operating frequency of the electric machine or the internal combustion engine which is also arranged in the vehicle drive train. In other words, during operation of the electric machine and / or the internal combustion engine, the line end section preferably has a natural frequency which is outside the operating frequency range between the joining point and the clamping point. Preferably, in particular, the line end section between the joining point and the clamping point has a natural frequency of greater than 3000 Hz, preferably greater than 3500 Hz, in particular greater than 4000 Hz. By shifting the natural frequency outside the operating frequency range, vibration excitation in the line end section, in particular in the region of the joining point, can be prevented.

[0017] In a specific embodiment, it is provided that the clamping location is arranged at more than 40% and less than 60% of the free wire length of the wire end section. Preferably, the clamping location is arranged substantially at 50% of the free wire length of the wire end section, i.e., half of the wire length. Specifically, this means that if the free wire length is halved, the natural frequency or natural mode of the wire end section doubles. Thus, the natural frequency of the wire end section can be specifically influenced in a simple manner according to the arrangement of the clamping location.

[0018] In a specific embodiment, it is provided that the wire end section leaves the winding of the single-tooth coil at the winding exit, wherein the free wire length is measured from the free wire end to the winding exit. Therefore, the clamping part is arranged between the free wire end and the winding exit. In other words, the clamping part is at least approximately arranged in a central position between the free wire end and the winding exit. In particular, the winding exit should be understood as the following part of the coil winding: the winding wire enters or leaves the winding at this part. In other words, the winding exit represents the beginning or end of the coil winding. In particular, the wire end section is deflected at least once relative to the coil winding direction and / or deformed at least once transversely to the coil winding direction. Particularly preferably, when the winding terminal connecting piece is located on the radial outside, the winding exit is located on the radial inside of the stator, and when the winding terminal connecting piece is located on the radial inside, the winding exit is located on the radial outside of the stator.

[0019] In another specific embodiment, it is provided that the wire end section is laid unsupported from the winding outlet along the radial direction relative to the main axis to the clamping position, and is laid unsupported from the clamping position to the joining position in the axial direction relative to the main axis. In other words, the wire end section is fixed only at the winding outlet, the clamping position and the joining position. In simple terms, the winding outlet, the clamping position and the joining position thus form vibration nodes respectively, wherein the wire end sections between the vibration nodes, i.e. the wire end sections in the unsupported area, respectively form vibration antinodes. In principle, the distance between the winding outlet and the clamping position can be equal to the distance between the clamping position and the joining position. Alternatively, the distance between the clamping position and the winding outlet is different from and / or greater than the distance between the clamping position and the joining position. In particular, the wire end section is deformed at least or exactly 90° in the direction of the winding terminal connecting piece after the clamping position. Therefore, a fixing method of the wire end section is proposed, which simultaneously allows free movement, in particular free vibration, between the fixing points.

[0020] In a specific embodiment, it is provided that the winding outlet is arranged to be located on the radial inner side, and the winding terminal connecting piece is arranged to be located on the radial outer side, wherein the clamping part is arranged at the limiting section located on the radial outer side. In particular, the terminal ring assembly has at least one or exactly one supporting section for each winding area, which is supported and / or can be supported at the limiting section located on the radial outer side. Preferably, the wire end section is therefore clamped in the axial direction between the limiting section located on the radial outer side and the supporting section located on the radial outer side. Specifically, this means that the supporting section is directly supported and / or can be supported at the limiting section located on the radial outer side in the radial direction, and at the same time is supported at the limiting section located on the radial outer side via the wire end section in the axial direction. Preferably, the wire end section is fixed in a force-transmitting connection manner in all spatial directions at the clamping part. As a result, the wire end section can be firmly clamped.

[0021] In another design, it is provided that the wire end section is clamped and fixed between the delimiting section and the supporting section at least in the axial direction with an interference fit at the clamping position. In particular, the wiring ring assembly is fixed in an axial position in the axial direction via an axial connection, wherein in this axial position, the wire end section is fixed by an interference fit, more precisely, a press fit between the delimiting section and the supporting section. For this purpose, at least in the region of the clamping position, the axial distance between the delimiting section and the supporting section is smaller than the wire diameter of the wire end section. In order to produce an interference fit, the wire end section is laid in the direction of the winding terminal connecting piece via the delimiting section, wherein the wiring ring assembly is then assembled and fixed in its axial position. Here, the wiring ring assembly is subjected to an axial preload force in order to produce an interference fit during the establishment of the axial connection and / or to apply a clamping force in the direction of the delimiting section to the wire end section at the clamping position. As a result, the wire end section can be fixed at the clamping position in a particularly simple and reliable manner.

[0022] In a kind of improvement scheme, it is provided that the delimiting section or the supporting section optionally has a wire guide opening configured for and / or suitable for guiding the wire end section, wherein the wire end section is received in the wire guide opening in a form-fitting manner at least in the circumferential direction and / or tangential direction relative to the main axis. The wire guide opening is preferably configured as a cutout portion of an axial opening, in which the wire end section is axially and / or tangentially located. As an example, the wire guide opening can be configured as a half hole and / or has a snap-on profile. Alternatively, the wire guide opening can also be configured as a penetration or a hole, through which the wire end section is guided. By receiving the wire end section in the wire guide opening in a form-fitting manner, the wire end section can be prevented from sliding between the delimiting section and the supporting section, thereby enabling particularly firmly fixing the wire end section.

[0023] In a specific design, it is provided that the wire guide opening is constructed as a V-shaped or U-shaped guide groove. Through the V-shaped or U-shaped guide groove, the wire end section can be fixed in the wire guide opening without gap. Preferably, the V-shaped or U-shaped guide groove is open in the axial direction so that the wire end section can be easily embedded in the wire guide opening. This makes it particularly easy to lay the wire end section.

[0024] In another embodiment, it is provided that the wire end section is connected to the delimiting section and / or the supporting section in a material connection at the clamping position. In particular, the wire end section can be materially connected to the delimiting section and / or the supporting section at the clamping position by gluing, painting, etc. Preferably, the wire end section is fixed at least in the wire guide opening in a material connection. Thus, the wire end section can be additionally fixed at the clamping position, thereby significantly reducing the loosening of the wire end section at the clamping position caused by, for example, vibration and / or friction.

[0025] In an improved scheme, it is provided that other delimiting sections have a wire deflection profile configured for and / or suitable for deflecting the wire end section, wherein the wire end section is deflected in the direction of the clamping position at the deflection position via the wire deflection profile. In particular, the winding outlet is arranged adjacent to the deflection section and / or adjacent to the deflection section. Preferably, the wire end section deflects at least once or exactly once at the deflection section. Preferably, the wire end section deflects more than 90°, preferably 180° at the deflection position. The wire deflection profile is used to deflect the wire in the direction of the relative delimiting section on the one hand, and to reduce the tensile load for the winding wire at the winding outlet on the other hand. As an example, the wire deflection profile can be formed by a bolt, a protrusion, a groove, etc. at the delimiting section. In particular, another vibration node is defined by the deflection position. This thus ensures a particularly reliable laying of the wire end section from the winding outlet to the winding terminal connecting piece. Furthermore, the free conductor length can be further shortened by the conductor deflection contour, in particular between the winding outlet and the clamping point.

[0026] In a specific embodiment, it is provided that the terminal ring assembly has a plurality of, preferably exactly three, busbars, at which at least one or more of the winding terminal connecting pieces are respectively constructed. The terminal ring assembly has an insulator in which the busbars are arranged in an electrically insulated manner from one another, wherein the support section is directly constructed at the insulator. In particular, the busbar is constructed as an annular disk, in particular made of a strip-shaped or plate-shaped copper semi-finished product. Preferably, the busbar is arranged in the insulator in a coaxial manner relative to the main axis and / or in an axially overlapping manner. In the design scheme in which the motor is designed as a three-phase AC motor, the terminal ring assembly has exactly three busbars, which are respectively powered with a phase offset of 120°. Preferably, the insulator and the support section are made of a common material segment, preferably made of a common plastic injection molding portion. This achieves a particularly stable design scheme for the support section and a convenient and cost-effective manufacturing.

[0027] In another specific embodiment, it is provided that a plurality of winding bodies each have at least one or exactly one fastening section, and the busbar assembly, in particular the insulator, each has a plurality of fastening receptacles, wherein the fastening sections are partially fixed in the axial direction in the respectively assigned fastening receptacles to form an axial connection. In particular, the fastening sections are fixed in the respective fastening receptacles at least in the axial direction in a form-fitting connection and / or a force-transmitting connection and / or a material connection. In principle, the fastening sections can be configured as axially oriented bolts, which are guided through the fastening receptacles and are fixed in the fastening receptacles at the end sides respectively via nuts. However, the fastening sections are preferably configured as pins formed directly on the insulator, which are guided through the respective fastening receptacles and are fixed in the axial position occupied by a subsequent hot caulking process or another connection technology. Preferably, the fastening sections, in particular after the axial connection has been produced, have axial stops acting on both sides, between which the terminal ring assembly, preferably the insulator, is fixed without play at least in the axial direction. In particular, each winding body has at least one, preferably two, fastening sections, wherein one fastening section is formed at each delimiting section. Thus, a particularly simple and cost-effective connection between the winding body and the terminal ring assembly is provided, wherein the axial connection can ensure a permanent fixation of the conductor end section at the clamping point.

[0028] In another specific embodiment, it is provided that each of the single-tooth coils has exactly two wire end sections, wherein one wire end section forms the winding start and the other wire end section forms the winding end. The two wire end sections are each connected to one of the winding terminal connecting pieces via a joint, preferably each, and are each clamped and fixed at a clamping point between the delimiting section and the supporting section. For this purpose, the delimiting section and / or the supporting section preferably has exactly two of the wire guide openings.

[0029] Another subject of the invention relates to an electric machine having a rotor and a stator as described above. In particular, the electric machine is configured and / or suitable for generating an electric drive torque, preferably a traction torque, of a vehicle. As an example, the electric machine is configured as a so-called traction machine. The electric machine can be integrated into an electric drive train, preferably into an electric axle. The electric drive train can be a purely electric drive train or a hybrid drive train. The electric machine is preferably configured as an inner rotor electric machine. In particular, the electric machine is connected to a dual clutch transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further features, advantages and effects of the present invention are derived from the following description of preferred embodiments of the present invention. In which:

[0031] Figure 1 A schematic cross-sectional view of a motor as an embodiment of the present invention is shown;

[0032] Figure 2 Shows Figure 1 A perspective view of a stator of an electric motor;

[0033] Figure 3 Shows Figure 2 Detailed cross-sectional view of the stator in FIG.

[0034] Figure 4 Shows Figure 2 Radial detail view of the stator in Figure 1. DETAILED DESCRIPTION

[0035] Figure 1 An electric machine 1 is schematically shown, which is designed as a three-phase AC machine in an internal rotor design, in particular a permanently excited synchronous machine. The electric machine 1 can be designed as a driving drive in a drive train of a hybrid vehicle or an electric vehicle.

[0036] The electric machine 1 comprises a stator 2 and a rotor 3 arranged radially inside the stator 2 and connected to a rotor shaft 4 in a rotationally fixed manner and supported rotatably about a main axis 100. As an example, the rotor 3 comprises a rotor lamination stack 5 in which a plurality of permanent magnets (not shown) are arranged spaced apart from each other in the circumferential direction.

[0037] The stator 2 has an annular stator body 6 around a main axis 100. The stator body is designed in segments along the circumferential direction and is composed of a plurality of identical stator segments 7 to form a closed ring. Figure 2 As shown. The main axis 100 thus also forms the center axis of the stator 2. As an example, the stator segment 7 can be designed as a laminated core. In the case of a prescribed installation, the stator body 6 is inserted in a rotationally fixed manner into a cylindrical stator support 8, which forms, for example, an outer housing or an intermediate housing of the motor 1.

[0038] The stator body 6 has an annular stator yoke 9 which rests on the stator support 8 and on which individual teeth 10 extend radially inward. The individual teeth 10 are each provided with a single tooth coil 12 to form a stator winding 11. The single tooth coil 12 is each formed by a winding wire 13, for example a round wire, which is wound by means of two winding bodies 14, 15 and fixed to prevent slipping. The winding bodies 14, 15 are formed, for example, of heat-resistant plastic.

[0039] The single-tooth coils 12 are assigned to electrically separate wiring harnesses of a wiring ring assembly 16, and the single-tooth coils 12 are connected to each other in a predetermined manner, for example, in a delta connection, via the wiring harnesses. The wiring ring assembly 16 is also connected to a power electronics device 18 and a power supply 19 via a power connection 17, which can apply a current of variable phase and amplitude to the stator winding 11 to operate the motor 1.

[0040] like Figure 2 As shown, the wiring ring assembly 16 is annular and has winding terminal connection pieces 20a, 20b, 20c for each single-tooth coil 12, respectively, through which the winding wire 13 is electrically contacted with the wiring ring assembly 16. The winding terminal connection pieces 20a, 20b, 20c are arranged at the radial outer side of the wiring ring assembly 16 and are evenly spaced apart from each other in the circumferential direction.

[0041] In addition, the connection ring assembly 16 has three power terminal connection pieces 21a, 21b, 21c to form a power connection portion 17, and the connection ring assembly 16 can be electrically connected to the power electronic device 18 via the power terminal connection pieces. In the case of a three-phase AC motor, the stator winding 11 has three phases, wherein each phase is provided with a power terminal connection piece 21a, 21b, 21c.

[0042] The connecting ring assembly 16 is arranged coaxially with the main axis 100 and is fixed to the winding body 14 via a plurality of axial connections 22 at the axial end side of the stator 2 in the axial direction relative to the main axis 100. As an example, the connecting ring assembly 16 is fixed to the winding body 14 via the axial connections 22 in a non-detachable and gap-free manner.

[0043] from Figure 3It can be seen that the terminal ring assembly 16 has three busbars 23a, 23b, 23c, which are embedded in the insulator 24 in an electrically insulated manner. The busbars 23a, 23b, 23c are made of copper semi-finished products, especially copper plates or copper sheets, as annular disks by means of stamping and forming processes. The busbars 23a, 23b, 23c are arranged coaxially with the main axis 100 and overlap each other in the axial direction. Each busbar 23a, 23b, 23c has a winding terminal connecting piece 20a, 20b, 20c and a power terminal connecting piece 21a, 21b, 21c respectively assigned. In the present case, the terminal ring assembly 16 is constructed as a metal-plastic composite component, wherein the busbars 23 a , 23 b , 23 c (in addition to the winding terminal lugs 20 a , 20 b , 20 c and the power terminal lugs 21 a , 21 b , 21 c ) are encapsulated with plastic to form an insulator 24 .

[0044] The winding bodies 14, 15 each have a winding region 25, wherein the winding wire 13 is wound around the respective single tooth 10 to form the single tooth coil 12. The winding region 25 is formed here by a base section 26 located at the end side of the single tooth 10 and two delimiting sections 27a, 27b protruding in the axial direction, which delimit the winding region 25 in the radial direction.

[0045] The single-tooth coil 12 has two wire end sections 28a, 28b to form a winding start and a winding end, respectively, and its free wire end 29 is joined with the associated winding terminal connecting piece 20a, 20b, 20c in a material connection manner at a joining position 30. As an example, the wire end 29 is welded and connected with the corresponding winding terminal connecting piece 20a, 20b, 20c at the joining position 30. For wiring, the two wire end sections 28a, 28b of two single-tooth coils 12 adjacent in the circumferential direction are respectively connected with the winding terminal connecting pieces 20a, 20b, 20c directly adjacent to each other.

[0046] The connecting ring assembly 16 has at least one supporting section 31 facing the winding area 25, via which the connecting ring assembly 16 is supported in the radial direction and / or can be supported at the radially outer delimiting section 27a of the winding body 14 to form a radial connection 32. In addition, the connecting ring assembly 16 has at least one further supporting section 33, via which the connecting ring assembly 16 is supported in the radially opposite direction and / or can be supported at the radially inner delimiting section 27b of the winding body 14 to form a radial connection 32. In this case, the supporting sections 31, 33 are arranged radially inside the winding area 25. The supporting sections 31, 33 are produced in one piece, for example, from a common plastic injection molding, and are configured as two circumferential or discontinuous axial projections on the underside of the insulating body 24.

[0047] The two conductor end sections 28a, 28b leave the winding region 25 radially on the inside at the winding outlet 34, wherein the conductor end sections 28a, 28b are usually laid unsupported up to the junction 30 and are therefore characterized by a correspondingly large free conductor length. During operation of the electric machine 1, the conductor end sections 28a, 28b may generate natural vibrations in the operating frequency range, which may lead to conductor failures due to vibration fatigue fracture of the copper material at the junction 30. Therefore, the two conductor end sections 28a, 28b are each clamped and fixed at a clamping point 35 between the outer limiting section 27a and the outer supporting section 31 in order to shorten or halve the free conductor length of the conductor end sections 28a, 28b. The clamping point 35 is preferably arranged at approximately 50% of the free conductor length between the junction 30 and the winding outlet 34.

[0048] like Figure 4 As shown, the delimiting section 27a located radially outside has a wire guide opening 36 for this purpose, through which the wire end sections 28a, 28b are guided. The wire guide opening 36 is constructed as a V-shaped insertion groove, into which the wire end sections 28a, 28b are axially inserted and held in a form-fitting connection and / or without gaps in the circumferential direction. For clamping and fixing, the wire end sections 28a, 28b are arranged between the delimiting section 27a and the support section 31 by means of a press fit, wherein the axial distance between the delimiting section 27a and the support section 31 in the area of ​​the wire guide opening 36 is smaller than the wire diameter of the winding wire 13.

[0049] In order to be able to exert a clamping force F on the conductor end sections 28a, 28b in the axial direction relative to the main axis 100, the connecting ring assembly 16 is fixed to the winding body 14 without play via the axial connection 22. For this purpose, the two delimiting sections 27a, 27b each have a fastening section 37, wherein a plurality of radially inner and radially outer fastening receptacles 38 distributed in the circumferential direction and each for accommodating the fastening sections 37 are formed on the insulating body 24.

[0050] The fastening receptacles 38 are designed as axial penetrations and the fastening sections 37 are designed as axially protruding pins, which are guided through the respective fastening receptacles 38 and are heat-caulked on the end side. As an example, a clamping force F can be applied to the wire ring assembly 16 during the heat caulking in order to clamp the wire end sections 28a, 28b in the respective wire guide openings 36 via the support sections 31. As an example, after the heat caulking, the fastening sections 37 can form axial stops acting on both sides in the axial direction, between which the wire ring assembly 16, in particular the insulator 24, is fixed without play at least in the axial direction, in order to maintain the clamping force F for a long time.

[0051] like Figure 3 As shown, the winding body 14 has a wire deflection contour 39 at the radially inner limiting section 27b, via which the wire end sections 28a, 28b are axially deflected at a deflection point 40 in the direction of the clamping point 35 after leaving the winding outlet 34. The wire deflection contour 39 is formed, for example, by a deflection groove formed at the radially inner limiting section 27b, via which the wire end sections 28a, 28b are deflected at least once and are held captively in the axial direction.

[0052] The conductor end sections 28a, 28b thus extend unsupported in a radial direction relative to the main axis 100 between the deflection point 40 and the clamping point 35, and extend unsupported in an axial direction relative to the main axis 100 between the clamping point 35 and the joining point 30. In this case, the conductor end sections 28a, 28b are deformed with their conductor ends 29 in the axial direction in the direction of the winding terminal lugs 20a, 20b, 20c after passing the clamping point 35, wherein the clamping point 35 is arranged approximately in the middle between the deflection point 40.

[0053] like Figure 4 As shown, in order to realize the delta connection, two adjacent wire ends 29 of two single-tooth coils 12 adjacent in the circumferential direction are connected to the winding terminal connecting pieces 20a, 20b, 20c. Therefore, the winding terminal connecting pieces 20a, 20b, 20c are respectively assigned two wire end sections 28a, 28b, which are positioned adjacent to the winding terminal connecting pieces 20a, 20b, 20c in the circumferential direction. The winding terminal connecting pieces 20a, 20b, 20c and the wire ends 29 are oriented parallel to each other, wherein the winding terminal connecting pieces 20a, 20b, 20c have a V-shaped widening portion.

[0054] List of reference numerals:

[0055] 1 Motor

[0056] 2 Stator

[0057] 3 Rotor

[0058] 4 Rotor shaft

[0059] 5 Rotor lamination pack

[0060] 6 Stator body

[0061] 7 Stator segment

[0062] 8 Stator bracket

[0063] 9 Stator yoke

[0064] 10 Single tooth

[0065] 11 Stator winding

[0066] 12 Single Tooth Coil

[0067] 13 Winding wire

[0068] 14 Winding body

[0069] 15 Additional winding bodies

[0070] 16 Wire Ring Assembly

[0071] 17 Power connection

[0072] 18 Power Electronics

[0073] 19 Power Supply

[0074] 20a-20c Winding terminal connection piece

[0075] 21a-21c Power terminal connection piece

[0076] 22 Axial connection

[0077] 23a-23c Bus

[0078] 24 Insulator

[0079] 25 Winding area

[0080] 26 Basic Section

[0081] 27a, 27b Limit sections

[0082] 28a, 28b Wire end section

[0083] 29 Wire end

[0084] 30 Joint

[0085] 31 Support section

[0086] 32 Radial connection

[0087] 33 Additional support sections

[0088] 34 Winding outlet

[0089] 35 Clamping area

[0090] 36 Wire guide opening

[0091] 37 Fastening section

[0092] 38 Fastening receiving portion

[0093] 39 Wire deflection profile

[0094] 40 Deflection point

[0095] 100 Main axis

[0096] F Clamping force.

Claims

1. A stator (2) for an electric motor (1), the stator comprising: a stator body (6) constructed around a main axis (100) and having a plurality of radially oriented individual teeth (10), A multi-phase stator winding (11) having a plurality of single-tooth coils (12) formed from winding wires (13), wherein: A single-tooth coil (12) is arranged at each single tooth (10). - a plurality of winding bodies (14, 15), wherein the winding bodies (14, 15) each have a winding region (25) for the single-tooth coil (12), the winding region being formed by a base section (26) located at the end side of one of the single teeth (10) and two limiting sections (27a, 27b) radially delimiting the winding region (25) and connected to the base section (26), - a connection ring assembly (16) for connecting the single-tooth coil (12), the connection ring assembly being fixed to a plurality of winding bodies (14, 15) at the axial end side of the stator (2), wherein the connection ring assembly (16) respectively has at least one supporting section (31, 33) facing the winding area (25), and the connection ring assembly (16) is supported in a radial direction at at least one of the limiting sections (27a, 27b) via the supporting section to form a radial connection (32), and wherein the terminal ring assembly (16) has a plurality of winding terminal connecting pieces (20a, 20b, 20c) for connecting to the single-tooth coil (12), wherein at least one wire end section (28a, 28b) of each winding wire (13) is joined at the end side with its free wire end (29) at a joining position (30) to the associated winding terminal connecting piece (20a, 20b, 20c) in a materially connected manner, It is characterized in that The wire end sections (28a, 28b) are clamped and fixed between one of the limiting sections (27a, 27b) and the corresponding support section (31, 33) at each clamping point (35) in order to shorten the free wire length of the wire end sections (28a, 28b).

2. The stator (2) according to claim 1, characterized in that The free line length of the line end sections (28a, 28b) is shortened to such an extent that the natural frequency of the line end sections (28a, 28b) is shifted outside the frequency range of the operating frequency of the electric machine (1).

3. The stator (2) according to claim 1 or 2, characterized in that: The clamping point (35) is arranged at a position greater than 40% and less than 60% of the free conductor length of the conductor end section (28a, 28b).

4. The stator (2) according to claim 3, characterized in that The conductor end sections (28a, 28b) leave the winding of the single-tooth coil (12) at a winding outlet (34), wherein the free conductor length is measured from the free conductor end (29) to the winding outlet (34).

5. The stator (2) according to claim 4, characterized in that The conductor end sections (28a, 28b) are laid unsupported starting from the winding outlet (34) in a radial direction relative to the main axis (100) to the clamping point (35), and are laid unsupported starting from the clamping point (35) in an axial direction relative to the main axis (100) to the joining point (30).

6. The stator (2) according to claim 4 or 5, characterized in that: The winding outlet (34) is arranged to be located radially inside, and the winding terminal connecting pieces (20a, 20b, 20c) are arranged to be located radially outside, wherein the clamping location (35) is arranged at the limiting sections (27a, 27b) located radially outside.

7. A stator (2) according to any one of the preceding claims, characterised in that The conductor end sections (28a, 28b) are clamped and fixed at the clamping location (35) between the limiting sections (27a, 27b) and the supporting sections (31, 33) by means of an interference fit at least in the axial direction.

8. A stator (2) according to any one of the preceding claims, characterised in that The limiting section (27a, 27b) or the supporting section (31, 33) has a wire guide opening (36) for guiding the wire end section (27a, 27b), wherein the wire end section (28a, 28b) is received in the wire guide opening (36) in a form-fitting manner at least in the circumferential direction.

9. The stator (2) according to claim 8, characterized in that The wire guide opening (36) is configured as a V-shaped or U-shaped guide groove.

10. The stator (2) according to any one of the preceding claims, characterized in that The conductor end sections (28a, 28b) are connected at the clamping point (35) to the limiting sections (27a, 27b) and / or the supporting sections (31, 33) in a materially connected manner.

11. The stator (2) according to any one of the preceding claims, characterized in that The other limiting section (27a, 27b) has a wire deflection contour (39) for deflecting the wire end section (28a, 28b), wherein the wire end section (28a, 28b) is deflected via the wire deflection contour (39) at a deflection point (40) in the direction of the clamping point (35).

12. The stator (2) according to any one of the preceding claims, characterized in that The terminal ring assembly (16) has an insulating body (24) in which at least one busbar (23a, 23b, 23c) having the winding terminal connecting pieces (20a, 20b, 20c) is arranged, wherein the supporting section (31, 33) is formed directly on the insulating body (24).

13. The stator (2) according to any one of the preceding claims, characterized in that A plurality of winding bodies in the winding bodies (14, 15) respectively have at least one fastening section (37), and the connecting ring assembly (16) correspondingly has a plurality of fastening receptacles (38), wherein the fastening sections (27) are locally fixed in the respectively assigned fastening receptacles (38) in the axial direction to form an axial connection (22).

14. The stator (2) according to any one of the preceding claims, characterized in that Each of the single-tooth coils (12) has exactly two wire end sections (28a, 28b), wherein one wire end section (28a, 28b) forms a winding start and the other wire end section (28a, 28b) forms a winding end, wherein the two wire end sections (28a, 28b) are respectively joined to winding terminal connecting pieces (20a, 20b, 20c) at a joining position (30) and are respectively clamped and fixed at a clamping position (35) between the limiting sections (27a, 27b) and the supporting sections (31, 33).

15. An electric machine (1) having a rotor (3) and a stator (2) according to any one of the preceding claims.

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