Stator, method for producing stator, fluid guiding body and electric machine

Abstract

The invention relates to a stator (1) in which a rotor (20) having an outer diameter (21) can be inserted so as to form a cylindrical air gap (22). The stator (1) has a plurality of stator teeth (5) each defining a respective stator groove (6) located between adjacent stator teeth (5) in a circumferential direction, extending in a radial direction, extending through the stator (1) in an axial direction, and comprising two groove side walls (7) and a groove base (8), an energizable winding (9) is inserted in the stator recess, said winding comprising a plurality of conductors (10). The winding (9) leaves the stator (1) at at least one first end face (11), so that a cylindrical first winding head (40) is formed, and a cooling fluid (12) can flow from the first end face (11) through the stator (1). According to the invention, the stator (1) has a cylindrical fluid guide body (14) through which the cooling fluid (12) can flow and which surrounds the first winding head (40) at least partially. According to the invention, at least one first conductor (10a) of the winding head (40) has a first contact section (41), which extends out of the winding head (40) in the axial direction and at least partially passes through a corresponding first electrical contact device (42), which is arranged in an electrical contact manner on the fluid-conducting body (14), the first electrical contact device (42) is coupled to a first electrical connection device (43) in an electrically conductive manner.

Description

Technical Field

[0001] The present invention relates to a stator for an electric machine, in particular a stator for an electric machine in a powertrain of a motor vehicle. The stator is designed in the form of a cylindrical ring with an inner diameter, into which a rotor with an outer diameter can be inserted, thereby forming a cylindrical air gap. The stator has a plurality of stator teeth, each stator tooth defining a corresponding stator groove. The stator groove is located between adjacent stator teeth in the circumferential direction, extends in the radial direction, and extends axially through the stator. The stator groove comprises two groove sidewalls and a groove base. A current-carryable winding comprising a plurality of conductors is inserted in the stator groove. The winding exits the stator at at least a first end face, thereby forming a cylindrical first winding head. A cooling fluid can flow through the stator from the first end face. The present invention also relates to a method for producing the stator, a fluid-guiding body, and an electric machine. Background Art

[0002] Electric motors are increasingly being used to power motor vehicles, creating an alternative to fossil fuel-intensive internal combustion engines. Significant efforts have been made to improve the suitability of electric drives for everyday use while also providing users with the driving comfort they are accustomed to.

[0003] A detailed description of an electric drive can be found in an article by Erik Schneider, Frank Fickl, Bernd Cebulski, and Jens Liebold published in the German automotive magazine ATZ, Vol. 113, May 2011, pp. 360-365, entitled: “Highly Integrative and Flexible Electric Drive Unit for E-Vehicles”. This article describes a drive unit for an axle of a vehicle, comprising an electric motor arranged concentrically and coaxially with respect to a bevel gear differential, a shiftable two-speed planetary gear set being arranged in the drive train between the electric motor and the bevel gear differential, and the planetary gear set likewise being positioned coaxially with the electric motor and the bevel gear differential or spur gear differential. The drive unit is very compact and, due to the switchable 2-speed planetary gear set, offers a good compromise between gradeability, acceleration and energy consumption. Such a drive unit is also known as an electric axle or electrically operable driveline.

[0004] In addition to purely electrically operated drivetrains, hybrid drivetrains are also known. Such drivetrains for hybrid vehicles typically include a combination of an internal combustion engine and an electric motor, and enable a purely electric operating mode that simultaneously provides sufficient range and usability, for example in urban areas, and particularly when driving off-road. Furthermore, in certain operating situations, propulsion can be provided by both the internal combustion engine and the electric motor simultaneously.

[0005] The development of electric motors intended for use in electric axles or hybrid modules is driven by the need to continuously increase their power density, making the cooling required for this purpose increasingly important. Due to the necessary cooling capacity, hydraulic fluids such as cooling oil have been established in most concepts for removing heat from the thermally loaded areas of the electric motor.

[0006] For example, jacket cooling and winding head cooling are known from the prior art for cooling electric machines by means of hydraulic fluid. In jacket cooling, the heat generated at the outer surface of the stator laminated core is transferred to the cooling circuit, while in winding head cooling, the heat transfer to the fluid takes place directly at the conductor outside the stator laminated core in the region of the winding head.

[0007] Other improvements are provided by separate cooling channels, which are introduced both in the stator laminated core (see, for example, EP 3 157 138 A1) and in grooves other than the conductors (see, for example, Markus Schiefer: Indirekte Wicklungskühlung von hochausgenutzten permanenterregten Synchronmaschinen mit Zahnspulenwicklung [Indirect Winding Cooling of Highly Utilized Permanently Excited Synchronous Machines with Toothed Coil Winding], thesis, Karlsruhe Institute of Technology (KIT), 2017).

[0008] The concept of flowing hydraulic fluid directly around the windings to increase power density is also known. Improving cooling through direct contact between the hydraulic fluid and the conductors in the grooves is known from the prior art itself. For example, DE 10 2015 013 018 A1 describes a solution for electric machines with single-tooth windings, in which the fluid flows directly around the winding, which is wound around the teeth.

[0009] Electric motors with a hollow cylindrical stator, i.e., designed as inner rotor machines and configured for use as traction drives for motor vehicles, typically have stator windings with a rectangular cross-section to achieve high power density. Therefore, in electric motors intended for driving motor vehicles, the stator windings are often designed as hairpin windings. In this case, for example, a roughly U-shaped conductor segment is introduced into a stator groove from one end face of the stator and then shaped at the opposite end face of the stator and connected, for example, by welding. Summary of the Invention

[0010] The object of the present invention is therefore to provide a stator for an electric machine that offers high power density and effective cooling and, in particular, is particularly easy and safe to install. Another object of the present invention is to provide an optimized electric machine and an optimized method for producing the stator. Furthermore, the object of the present invention is to provide an improved fluid-guiding body for a stator of an electric machine.

[0011] This object is achieved by a stator for an electric machine, in particular an electric machine in a drive train of a motor vehicle, wherein the stator is designed in the form of a cylindrical ring with an inner diameter, into which a rotor with an outer diameter can be inserted, thereby forming a cylindrical air gap, and wherein the stator has a plurality of stator teeth, each stator tooth defining a corresponding stator groove, the stator groove being located between adjacent stator teeth in the circumferential direction, extending in the radial direction, and extending through the stator in the axial direction, and the stator groove comprising two groove side walls and a groove base, wherein an electrically energizable winding is inserted in the stator groove, the winding comprising a plurality of conductors, wherein the winding leaves the stator at at least a first end face, thereby forming a cylindrical first winding head, and wherein a cooling fluid can be supplied from the first end face to the stator. An end face flows through the stator, wherein the stator has a cylindrical fluid-guiding body, through which the cooling fluid can flow, and the cylindrical fluid-guiding body at least partially surrounds the first winding head, wherein at least one first conductor of the winding head has a first contact section, which extends out of the winding head in an axial direction and at least partially passes through a corresponding first electrical contact device, which is arranged on the fluid-guiding body in an electrically conductive manner, wherein the first electrical contact device is connected to a first electrical connection device in an electrically conductive manner, by means of which electrical contact can be established between the first conductor and an inverter that energizes the winding via an outer side of the fluid-guiding body facing away from the cooling fluid.

[0012] This has the advantage of providing electrical contact with the stator winding heads. Axially arranging the fluid-guiding body allows the wiring of the actively cooled stator to be transferred from the wet chamber to the dry chamber in an assembly-friendly manner. This means that the contact between the winding and the inverter can be routed out of the oil chamber while ensuring oil-tightness. The corresponding terminal elements, in particular the electrical contact means and the electrical connection means, can be pre-assembled on the fluid-guiding body before installation, further simplifying manufacturing and assembly. Thus, contact with the winding is established when the fluid-guiding body is mounted opposite the winding heads.

[0013] For example, welding the conductors to the corresponding contact means may produce electrical contact and at the same time oil-tightness.Alternatively or additionally, the conductors may be connected to the contact means by crimping and / or clamping.

[0014] Furthermore, the electrical connection device can be a busbar segment with an opening, preferably a hole, through which the corresponding contact element is fastened to the inverter, for example, using additional screws and nuts. The electrical connection device can also have an internal thread in its opening, allowing the contact element to be screwed directly into the inverter. Alternatively, a sleeve with an internal thread can be pressed into the opening of the connection device. For example, by positioning the internal thread in the fluid-guiding body axially offset toward the stator so that it does not protrude from the base of the fluid-guiding body, a particularly compact design can be achieved.

[0015] The fluid guiding body is preferably made of plastic.It may also be preferred that the electrical contact device and the associated electrical connection device are formed as a single piece, in particular integrally.

[0016] Windings with conductors can particularly preferably be embedded in stator slots of a stator according to the present invention. The conductors are, in particular, electrically conductive conductors having two conductor sections that extend parallel to each other and include a longitudinal extension that is significantly greater than their diameter. In principle, the conductor sections can have any cross-sectional shape except for a circular shape. Rectangular cross-sectional shapes are preferred because they allow for a high packing density and, therefore, a high power density. The conductors are particularly preferably formed from copper. The conductors are preferably insulated. For example, mica paper can be wound in the form of a tape around one or more stator windings, which are impregnated with a curing resin. For mechanical reasons, the mica paper can be reinforced with glass fiber carriers. In principle, a curable lacquer layer without mica paper can also be used to insulate the conductors.

[0017] Most preferably, the winding is designed as a hairpin winding or a wave winding.In this context, it is further preferred that the conductor is designed as a hairpin conductor.

[0018] The stator according to the invention also has a stator body. The stator body can be manufactured in one piece or in multiple pieces, in particular in segments. A one-piece stator body is characterized by the fact that the entire stator body is formed as a single piece when viewed circumferentially. The stator body is usually formed from a plurality of stacked laminated electrical steel sheets, each of which is closed to form a circular ring. A segmented stator body is characterized by the fact that it is constructed from individual stator segment parts. The stator body can be constructed from individual stator teeth or groups of stator teeth, and each individual stator tooth or each individual group of stator teeth can be formed from a plurality of stacked laminated electrical steel sheets, each of which is designed as a stator segment laminate part.

[0019] The stator body is preferably formed from one or more stator laminated cores. A stator laminated core is understood to mean a plurality of laminated individual laminations or stator sheets, which are typically made from electrical steel sheets and are layered and packaged one on top of the other to form a stack or so-called stator laminated core. The individual laminations can then be held together in the laminated core by adhesive bonding, welding, or screwing.

[0020] The stator teeth of the stator are preferably formed in the stator body. Stator teeth are components of the stator body designed as radially inwardly pointing, circumferentially spaced, tooth-like sections of the stator body, with an air gap for the magnetic field formed between the free ends of the stator teeth and the rotor body. The gap between the rotor and the stator is called the air gap. In radial flux machines, the air gap is a generally annular gap with a radial width that corresponds to the distance between the rotor body and the stator body.

[0021] In particular, the stator can be configured for use in an electric motor within a motor vehicle's drivetrain. The electric motor is particularly intended for use within the drivetrain of a hybrid or fully electric motor vehicle. In particular, the electric motor is dimensioned to enable vehicle speeds exceeding 50 km / h, preferably exceeding 80 km / h, and particularly exceeding 100 km / h. The electric motor particularly preferably has an output exceeding 30 kW, preferably exceeding 50 kW, and particularly exceeding 70 kW. Furthermore, it is preferred that the electric motor provide a rotational speed exceeding 5,000 rpm, particularly preferably exceeding 10,000 rpm, and very particularly preferably exceeding 12,500 rpm.

[0022] According to an advantageous embodiment of the invention, several of the electrical conductors, preferably all of the electrical conductors, have a substantially rectangular profile in cross section. This embodiment has the advantage that commonly available standard electrical conductors can be used to form the stator winding, which is particularly advantageous with regard to the manufacturing costs of the stator.

[0023] The function of the cooling fluid in the stator according to the invention is to dissipate heat from the hot areas of the stator as efficiently as possible and to prevent these areas from overheating. In addition to this primary task, the cooling fluid can also provide lubrication and corrosion protection, in particular for the moving parts and / or metal surfaces of the cooling system of the stator or electric machine. Furthermore, the cooling fluid can also, in particular, remove contaminants (e.g., such as those caused by wear), water, and air. The cooling fluid is preferably a liquid. The cooling fluid can, in particular, be oil. However, in principle, it is also conceivable to use an aqueous cooling fluid, for example, also an emulsion, such as a water-glycol mixture.

[0024] The cooling fluid of the stator can be connected to a hydraulic cooling system via a hydraulic cooling circuit. This hydraulic cooling system is used to dissipate heat generated by electrical losses within the electric machine. This cooling system can have cooling channels in the rotor (rotor cooling channels) and / or in the stator (stator cooling channels), in particular also flows through stator grooves, through which the corresponding cooling fluid is guided for the purpose of removing heat.

[0025] The cooling fluid can particularly preferably be pumped through a hydraulic circuit by means of a pump. In principle, it is conceivable to design multiple hydraulic circuits for cooling the electric machine. In this case, it is highly preferred that the cooling channels of the stator be connected to the hydraulic cooling circuit or to various cooling circuits of the cooling system. In particular, connection to several cooling circuits allows for more precise cooling, since, for example, the temperature of the cooling fluid upon entry into the cooling channels of the stator, the flow rate of the cooling fluid, or even the type of cooling fluid (oil, emulsion) can be adjusted.

[0026] The stator groove is preferably closed by a groove closing device, so that cooling fluid cannot flow from the stator groove into the air gap between the rotor and the stator. Particularly preferably, the groove closing device is a groove closing wedge.

[0027] For the purposes of this application, a motor vehicle is a land vehicle that moves by machine power without the constraints of railway tracks.The motor vehicle may for example be selected from the group of: a passenger car, a truck, a scooter, a light motor vehicle, a motorcycle, a bus / coach or a tractor.

[0028] Further advantageous embodiments of the invention are described in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technically meaningful manner and can define further embodiments of the invention. Furthermore, the features indicated in the claims are described and explained in more detail in the description, wherein further preferred embodiments of the invention are presented.

[0029] According to a preferred embodiment of the present invention, it can be provided that the second conductor of the winding head has a second contact section, which extends out of the winding head in an axial direction and at least partially passes through a corresponding second electrical contact device, which is arranged on the fluid guiding body in an electrically contacting manner, wherein the second electrical contact device is connected to the second electrical connection device in an electrically conductive manner, by means of which an electrical contact can be established between the second conductor and an inverter that energizes the winding via the outer side of the fluid guiding body facing away from the cooling fluid, and / or the third conductor of the winding head has a third contact section, which extends out of the winding head in an axial direction and at least partially passes through a corresponding third electrical contact device, which is arranged on the fluid guiding body in an electrically contacting manner, wherein the third electrical contact device is connected to the third electrical connection device in an electrically conductive manner, by means of which an electrical contact can be established between the third conductor and the inverter that energizes the winding via the outer side of the fluid guiding body facing away from the cooling fluid. The advantage of this embodiment is that it allows multi-phase, in particular three-phase, current flow of the stator windings with correspondingly easy-to-install electrical contacting due to the axial arrangement of the fluid-conducting body.

[0030] According to another preferred further development of the invention, it can also be provided that the first electrical contact device and / or the second electrical contact device and / or the third electrical contact device each have a material connection to the fluid-conducting body, in particular are bonded or overmolded.

[0031] On the one hand, a defined positioning of the contact device to the fluid guiding body can be achieved and furthermore a sealing of the contact device relative to the fluid guiding body can also be achieved.For example, the contact device can be overmolded to form the fluid guiding body during an injection molding process.

[0032] In principle, the first electrical contact device and / or the second electrical contact device and / or the third electrical contact device can also be attached to each other by means of a force-fit connection and / or a form-fit connection. Specifically, the first electrical contact device and / or the second electrical contact device and / or the third electrical contact device can each be connected to the fluid guiding body by means of a press connection. The first electrical contact device and / or the second electrical contact device and / or the third electrical contact device can also each have an external thread, so that the contact device can be locked by a nut and fixed to the fluid guiding body.

[0033] It can also be advantageous if the contact means are substantially identical. In this context, it is also preferred that the electrical connection means are also designed in the same way. The electrical connection means can be formed as a single piece with the contact means, in particular integrally, or attached to the contact means as a separate component.

[0034] Furthermore, according to an equally advantageous embodiment of the invention, it can be provided that the first electrical contact device and / or the second electrical contact device and / or the third electrical connection device each have a conical insertion section which widens in the direction of the first winding head, so that the electrical conductor to be connected can be screwed into the electrical contact area provided during assembly of the fluid guiding body and, in addition, a certain tolerance compensation can be provided during assembly, which can also facilitate assembly.

[0035] According to another particularly preferred embodiment of the present invention, it can be provided that the first electrical contact device has a first opening, the first conductor passes through the first opening and protrudes from the first opening of the first electrical contact device, and / or

[0036] The second electrical contact device has a second opening, through which the second conductor extends and projects from the second opening of the second electrical contact device, and / or the third electrical contact device has a third opening, through which the third conductor extends and projects from the third opening of the third electrical contact device. This makes it particularly easy to visually check whether the fluid-guiding body has been successfully and completely seated on the winding head. Furthermore, the conductor segments protruding from the openings can be welded to the contact device particularly easily, thereby simultaneously forming a fluid-tight connection between the corresponding conductor and the contact device.

[0037] Furthermore, the present invention can be further developed so that the cylindrical fluid-guiding body comprises an annular base, an inner shell extending axially from the base, and an outer shell extending axially from the base, wherein the inner shell has an inner diameter that is greater than or equal to the outer diameter of the rotor. This has the advantage that the rotor can be axially inserted into the stator in a particularly simple manner, the stator then already being fully assembled and equipped with the fluid cooling system. This means that the fluid-guiding body can first be connected to the stator's connection body, thereby assembling the fluid cooling system and the electrical connections for the stator's winding heads. The rotor can then be axially inserted into the ready-to-operate stator, simplifying assembly and production logistics.

[0038] The connection between the fluid-guiding body and the connecting body is particularly preferably oil-tight, for example, by using suitable seals such as O-rings or by bonding. To achieve a particularly good bond, the connecting groove can preferably provide a defined adhesive gap as an adhesive joint, for example, a V-shaped adhesive joint. The adhesive is applied as a continuous bead around the entire circumference at the base of the connecting groove. This ensures that the adhesive is present over the entire circumference. During assembly of the fluid-guiding element, the adhesive is then pressed into the connecting groove over the entire circumference using a connecting collar that engages in the connecting groove, thereby forming a closed adhesive ring in the connecting groove, enabling an oil-tight bond. This can be used, in particular, to define a dry space within the stator.

[0039] In addition, the fluid guiding body can preferably be precisely positioned in the circumferential direction relative to the stator and / or the connecting body by means of suitable centering devices, so that, for example, the fluid connection of the fluid guiding body can meet the corresponding fitting hole in the corresponding electrical contact device and / or the corresponding conductor of the winding head without further tolerance compensation.

[0040] The windings inserted into the stator slots preferably extend out of the stator, forming winding heads on each of the two end faces of the stator, wherein at least one connecting body is molded into or onto the stator body of the stator. This has the advantage that a number of different functions can be provided in a component produced by injection molding using the injection-molded connecting body. For example, these functions of the connecting body can be selected from the group consisting of: fixing, locking, insulating, and / or sealing.

[0041] In an equally preferred embodiment of the present invention, it can also be provided that the first electrical contact device and / or the second electrical contact device and / or the third electrical contact device are each arranged on the base of the cylindrical fluid-guiding body. This allows for a particularly easy-to-install connection between the corresponding conductor of the winding head and the contact device, which is formed by pushing the fluid-guiding body axially onto the winding head. Furthermore, the corresponding electrical connection devices can also be connected via the base of the fluid-guiding body to facilitate installation.

[0042] The object of the present invention is also achieved by a method for producing a stator for an electric machine, in particular for an electric machine in a drive train of a motor vehicle, comprising the following steps:

[0043] a cylindrical stator with an inner diameter is provided, into which a rotor with an outer diameter can be inserted, thereby forming a cylindrical air gap, and the stator has a plurality of stator teeth, each stator tooth defining a corresponding stator groove, the stator groove being located between adjacent stator teeth in the circumferential direction, extending in the radial direction, extending through the stator in the axial direction and comprising two groove sidewalls and a groove base, a winding that can be electrically connected is inserted in the stator groove, the winding comprising a plurality of conductors, wherein the winding exits the stator at at least a first end face, thereby forming a cylindrical first winding head, and wherein a cooling fluid can flow through the stator from the first end face, wherein at least a first conductor of the first winding head has a first contact section extending out of the winding head in the axial direction,

[0044] providing a cylindrical fluid-guiding body through which the cooling fluid can flow, wherein the first winding head can be at least partially surrounded by the fluid-guiding body,

[0045] Arranging a first electrical contact device on the fluid-guiding body, through which the first contact section of the first electrical conductor can at least partially pass in an electrical contacting manner,

[0046] Arranging the fluid-conducting body on the first winding head so as to establish electrical contact between the first contact section and the first electrical contact device.

[0047] This has the advantage that the fluid guiding body can be preassembled with the electrical contact device as a component and the corresponding conductors of the winding head can then be electrically connected by sliding them axially onto the winding head for easier installation.

[0048] The objects of the present invention are also achieved by a fluid-guiding body for a stator of an electric machine, wherein the fluid-guiding body is designed to be cylindrical and through which a cooling fluid can flow, wherein a first electrical contact device arranged on the fluid-guiding body can at least partially make electrical contact with a first conductor of a winding head and is connected to a first electrical connection device in an electrically conductive manner, by means of which an electrical contact can be established between the first conductor and an inverter that energizes the winding via an outer side of the fluid-guiding body remote from the cooling fluid.

[0049] Finally, the object of the invention is also achieved by an electric machine, in particular in a drive train of a motor vehicle, characterized in that it comprises a stator according to one of claims 1 to 7 . BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The invention is explained in more detail below with reference to the accompanying drawings without limiting the general idea of ​​the invention.

[0051] In the attached figure:

[0052] Figure 1 A motor vehicle comprising an electric axle drive train is shown in a schematic representation,

[0053] Figure 2 The motor is shown in cross section,

[0054] Figure 3 The stator is shown in a perspective axial cross-section,

[0055] Figure 4 A first detailed view of an electric machine with an integrated fluid guiding body is shown in axial section,

[0056] Figure 5 shows a perspective view of a stator body with a connecting body,

[0057] Figure 6 shows a perspective view of the fluid guide body,

[0058] Figure 7 A first embodiment of the fluid guide body is shown in a perspective view.

[0059] Figure 8 A first embodiment of the fluid guiding body is shown in a first radial cross-sectional view,

[0060] Figure 9 A first embodiment of the fluid guiding body is shown in a second radial cross-section.

[0061] Figure 10 A first embodiment of the fluid guiding body is shown in a tangential cross-sectional view,

[0062] Figure 11 A second embodiment of the fluid guiding body is shown in a perspective view.

[0063] Figure 12 A second embodiment of the fluid guiding body is shown in radial cross-section.

[0064] Figure 13 A third embodiment of the fluid guiding body is shown in a perspective view.

[0065] Figure 14 A third embodiment of the fluid guiding body is shown in radial cross-section.

[0066] Figure 15 A first embodiment and a second embodiment of a contact device are shown in schematic sectional views,

[0067] Figure 16 A third and a fourth embodiment of a contact arrangement are shown in schematic sectional views,

[0068] Figure 17 A fifth embodiment of the contacting device is shown in a schematic sectional view. DETAILED DESCRIPTION

[0069] Figure 2 The stator 1 is shown for an electric machine 2, in particular an electric machine in a drive train 3 of a motor vehicle 4, as can also be seen in FIG. Figure 1 As can be seen by way of example in FIG. The stator 1 is designed as a cylindrical element with an inner diameter 17, into which a rotor 20 with an outer diameter 21 can be inserted, thereby forming a cylindrical air gap 22. Furthermore, the stator 1 has a plurality of stator teeth 5, each of which defines a stator groove 6 between adjacent stator teeth 5 in the circumferential direction. The stator grooves extend radially and axially through the stator 1 and have two groove sidewalls 7 and a groove base 8. A current-carrying winding 9 comprising a plurality of conductors 10 is inserted into the stator grooves. In the illustrated configuration, the electric machine 2 is designed as an internal rotor.

[0070] like Figure 3 As shown in FIG, the stator 1 has a connecting body 13 on a first end face 11, which extends at least partially away from the first end face 11 in the axial direction. This connecting body 13, in turn, has a first cylindrical connecting section 23 extending axially from the stator body of the stator 1 and radially below the winding heads of the windings 9. In the illustrated embodiment, the connecting body 13 also has a second cylindrical connecting section 24 extending axially from the stator body of the stator 1 and radially above the winding heads of the windings 9. Thus, the winding heads are enclosed by an annular space defined by the inner cylindrical connecting section 23 and the outer cylindrical connecting section 24. The connecting sections 23, 24 can be formed in two pieces and not physically connected to each other, but are molded into the stator body of the stator 1 in the same injection molding process. Here, the connecting sections 23, 24 are molded from the same plastic. Figure 3 An embodiment is shown in which the connecting body 13 is also formed on the end face of the stator 1 opposite to the end face 11 .

[0071] exist Figure 3 In the embodiment shown in FIG, a connection body 13 formed of plastic is injection molded onto the end face 11 of the stator 1, for example using a corresponding injection molding process. The stator groove 6 and its groove side walls 7 and corresponding groove base 8 are also at least partially injection molded with a plastic coating that is formed integrally with the connection body 13.

[0072] Especially from Figure 4As can be seen in the figure, cooling fluid 12 can flow through stator 1 from at least first end face 11. To supply cooling fluid 12, stator 1 has a cylindrical, fluid-guiding body 14 with an annular base 15, an inner shell 16 extending axially from base 15, and an outer shell 26 extending axially from base 15. In this configuration, fluid-guiding body 14 is reminiscent of a doughnut baking mold. Inner shell 16 has an inner diameter 18 that is greater than or equal to outer diameter 21 of rotor 20, allowing rotor 20 to be pushed axially into stator 1 from end face 11. To this end, inner diameter 18 of cylindrical, fluid-guiding body 14 can also be greater than or equal to inner diameter 17 of stator 1, which also allows for axial insertion of rotor 20 during assembly of electric machine 2. Connecting body 13 is molded onto and attached to the laminated core of the stator body of stator 1. Thus, the fluid-guiding body 14 is joined to the connecting body 13 at two coaxially extending cylindrical connecting sections 23, 24. The adhesive bond between the connecting body 13 and the fluid-guiding body 14 is oil-tight, so that, for example, no O-rings are required. The connecting body 13 and the fluid-guiding body 14 have centering devices 35, 36 for correctly positioning the connecting body and the fluid-guiding body relative to each other in a rotationally correct manner, as will be explained in more detail later.

[0073] Furthermore, the fluid-guiding body 14 has, on its outer jacket 26, fluid connections 19 extending radially from the outer jacket 26, via which the cooling fluid 12 can be guided through the fluid-guiding body 14 and via the connection body 13 into the stator grooves 6, where it can accordingly cool the windings 9 of the stator 1. This is also referred to as direct groove cooling.

[0074] The inner jacket 16 and outer jacket 26 of the fluid-guiding body 14 are fixed to the connecting body 13 by means of adhesive bonding. To this end, the connecting body 13 has a cylindrical inner connecting section 23 on the inner diameter 17 of the stator 1. This cylindrical inner connecting section extends axially from the stator 1, and the inner jacket 16 of the fluid-guiding body 14 is fixed to this cylindrical inner connecting section by means of adhesive bonding. In addition, the connecting body 13 has a cylindrical outer connecting section 24 extending axially from the stator 1, and the outer jacket 26 of the fluid-guiding body 14 is also fixed to this cylindrical outer connecting section by means of adhesive bonding.

[0075] exist Figures 5 and 6In the embodiment, the presence of three centering devices 35, 36, arranged asymmetrically around the circumference, allows the fluid guiding body 14 to be installed only in a defined circumferential position relative to the connecting body 13, representing a foolproof solution. As long as the corresponding pairs of centering devices 35, 36 are not arranged in their defined circumferential engagement position relative to one another, the sections of the fluid guiding body 14 to be joined will not come into contact with the V-shaped connecting grooves 27, 31 of the connecting body 13. Consequently, the adhesive layer remains uninterrupted. Figure 5 Possible arrangements of groove-shaped centering devices 36 on the connection body 13 are shown, in which the grooves are rotated relative to one another by 105°, 120°, and 135°. A solution with only one groove-shaped centering device 36 is also conceivable, wherein auxiliary means can preferably be used for assembly to avoid tilting before rotational positioning and thus avoid contact between the sealing surfaces in the two V-shaped grooves.

[0076] The winding 9 of the stator 1 leaves the stator 1 at a first end face 11, thereby forming a cylindrical first winding head 40. A cylindrical fluid-guiding body 14, through which the cooling fluid 12 can flow, at least partially surrounds the first winding head 40, wherein at least one first conductor 10a of the winding head 40 has a first contact section 41, which extends from the winding head 40 in the axial direction and at least partially passes through a corresponding first electrical contact device 42, which is arranged on the fluid-guiding body 14 in an electrically conductive manner, wherein the first electrical contact device 42 is connected to a first electrical connection device 43 in an electrically conductive manner, by means of which an electrical contact can be established between the first conductor 10a and an inverter 44 that energizes the winding 9 via an outer side 45 of the fluid-guiding body 14 facing away from the cooling fluid 12. This can be achieved in a manner that Figures 7 to 14 This is seen using the three stator designs outlined here.

[0077] The fluid guiding body 14 thus separates an inner wetted area of ​​the stator 1 , which is acted upon by the cooling fluid 12 , from a dry area located outside the fluid guiding body 14 .

[0078] exist Figures 7 to 14In the embodiments illustrated in the figures, the second conductor 10b of the winding head 40 has a second contact section 51, which extends from the winding head 40 in the axial direction and at least partially passes through a corresponding second electrical contact device 52, which is arranged on the fluid guiding body 14 in an electrically conductive manner, wherein the second electrical contact device 52 is connected to a second electrical connection device 53 in an electrically conductive manner, by means of which an electrical contact can be established between the second conductor 10b and the inverter 44 that energizes the winding 9 via the outer side 45 of the fluid guiding body 14 facing away from the cooling fluid 12. The third conductor 10c of the winding head 40 also has a third contact section 61, which extends axially from the winding head 40 and at least partially passes through a corresponding third electrical contact device 62, which is arranged on the fluid-guiding body 14 in an electrically conductive manner. The third electrical contact device 62 is electrically conductively connected to a third electrical connection device 63, by means of which an electrical contact can be established between the third conductor 10c and the inverter 44 that energizes the winding 9 via the outer side 45 of the fluid-guiding body 14 facing away from the cooling fluid 12. It will be understood that the contact devices 42, 52, 62 are formed from an electrically conductive material, while the fluid-guiding body 14 is formed from an electrically insulating material.

[0079] exist Figures 7 to 14 In the embodiment shown in FIG, the first electrical contact device 42 , the second electrical contact device 52 and the third electrical contact device 62 each have a material connection to the fluid guiding body 14 , which can be designed as a bonded connection or an overmolded connection.

[0080] The first electrical contact device 42, the second electrical contact device 52 and the third electrical contact device 62 each have a conical insertion section 46, which widens in the direction of the first winding head 40. With the help of this conical insertion section, when the fluid guiding body 14 is axially placed on the winding head 40, the corresponding electrical conductor 10a, 10b, 10c is guided in the direction of the corresponding opening 47, 57, 67.

[0081] Figures 7 to 14As further shown, the first electrical contact device 42 has a first opening 47, through which the first conductor 10a extends and protrudes from the first opening 47 of the first electrical contact device 42. The same applies to the second electrical contact device 52, which also has a second opening 57, through which the second conductor 10b extends and protrudes from the second opening 47 of the second electrical contact device 52. Accordingly, the third electrical contact device 62 also has a third opening 67, through which the third conductor 10c extends and protrudes from the third opening 67 of the third electrical contact device 62. The sections of the conductors 10a, 10b, 10c that protrude from the contact devices 52, 52, 62 can be welded around their entire perimeter, so that the corresponding openings 47, 57, 67 are fluid-tightly sealed.

[0082] Figures 7 to 14 As also shown, the cylindrical fluid-guiding body 14 has an annular base 15, an inner shell 16 extending axially from the base 15, and an outer shell 26 extending axially from the base 15. The inner shell 16 has an inner diameter 18 that is greater than or equal to the outer diameter 21 of the rotor 20, so that the rotor 20 can be axially inserted into the stator 1 even after the fluid-guiding body 14 has been fixed to the stator. A first electrical contact device 42, a second electrical contact device 52, and a third electrical contact device 62 are each arranged on the base 15 of the cylindrical fluid-guiding body 14.

[0083] Figures 7 to 14 The stator 1 shown in can be manufactured or assembled as follows: initially, a cylindrical stator 1 with an inner diameter 17 is provided, into which a rotor 20 with an outer diameter 21 can be inserted, thereby forming a cylindrical air gap 22, and the stator 1 has a plurality of stator teeth 5, each stator tooth defining a corresponding stator groove 6, the stator groove being located between adjacent stator teeth 5 in the circumferential direction, extending in the radial direction, extending through the stator 1 in the axial direction and comprising two groove side walls 7 and a groove base 8, a energizable winding 9 is inserted in the stator groove, the winding comprising a plurality of conductors 10, wherein the winding 9 leaves the stator 1 at at least a first end face 11, thereby forming a cylindrical first winding head 40, and wherein a cooling fluid 12 can flow through the stator 1 from the first end face 11, wherein at least the first conductor 10a of the first winding head 40 has a first contact section 41 extending from the winding head 40 in the axial direction.

[0084] Subsequently, a cylindrical fluid-guiding body 14 can be provided through which the cooling fluid 12 can flow, wherein the first winding head 40 can be at least partially surrounded by the fluid-guiding body 14. A first electrical contact device 42 can then be arranged on the fluid-guiding body 14, through which the first contact section 41 of the first electrical conductor 10a can at least partially pass in electrical contact. Finally, the fluid-guiding body 14 can then be placed on the first winding head 40, thereby establishing electrical contact between the first contact section 41 and the first electrical contact device 42.

[0085] In this way, first, fluid-guiding body 14 is provided, wherein first electrical contact means 42 arranged on fluid-guiding body 14 can be at least partially electrically contacted by first conductor 10a of winding head 40 and is electrically conductively connected to first electrical connection means 43, by means of which electrical contact can be established between first conductor 10a and inverter 44, which energizes winding 9, via outer side 45 of fluid-guiding body 14 facing away from cooling fluid 12. In this way, a structural unit comprising fluid-guiding body 14 and power supply connections can be formed between winding head 40 and inverter 44, which accordingly simplifies assembly.

[0086] The following briefly describes Figures 7 to 14 Three different embodiments of the fluid-guiding body 14 are shown in FIG.

[0087] Figures 7 to 10 A first embodiment of a fluid guiding body 14 is shown. Here, three contact devices 42, 52, 62 of identical design are each inserted into a groove 49 formed in the base 15 of the fluid guiding body 14. The contact devices 42, 52, 62 each have a connecting device 43, 53, 63 in the form of an internal thread, which is formed integrally with the contact device 43, 53, 63 and extends axially in the direction of the winding head 40 and therefore does not protrude axially beyond the contact device 42, 52, 62. As in Figure 10 As can also be seen in FIG, the internal thread can also be formed on a separate sleeve that is pressed with the contact device 42, 52, 62, which then forms the corresponding connecting device 43, 53, 63. For example, the contact can be made here by a screw connection screw, which can then be used to fix the electrical conductor leading to the inverter 44 to the connecting device 43, 53, 63.

[0088] Figures 11 to 12A second embodiment of the fluid-guiding body 14 is shown. The contact device 42 is also housed in the groove 49 of the fluid-guiding body 14 and is either integrated therein or overmolded thereto. The connection device 53 is designed here as a busbar extending from the contact device 42, into which, for example, a cable connector with electrical conductors leading to the inverter 44 can be plugged. The connection device 53 and the contact device 42 are integrally formed.

[0089] Figures 13 and 14 A third alternative embodiment of the fluid guiding body 14 is shown. Here, the connection device 43 is designed as a separate component from the contact device 42, is axially attached to the contact device 42 and has an opening 48 by means of which the connection to the inverter can be made. The opening 48 can then protrude radially beyond the stator 1, which is Figure 13 Clearly illustrated in the figure.

[0090] Figures 15 to 17 Various embodiments of the contact device 42 and its connection to the fluid-guiding body 14 and the electrical conductor 10 are shown.

[0091] Figure 15 The embodiment shown in FIG. a shows a cap-shaped contact device 42 that is pressed into a corresponding opening in the fluid-guiding body 14 and protrudes from the outer side 45 of the fluid-guiding body 14. On the side of the fluid-guiding body 14 facing away from the outer side 45, the cap-shaped contact device 42 abuts a collar having a circumferential groove formed therein for receiving a seal 38, which seals the contact device 42 relative to the fluid-guiding body. The opening 47 of the contact device 42, through which the electrical conductor 10a of the winding head 40 passes, is sealed fluid-tight by a weld head 54. Figure 15 Figure b shows an embodiment in which a threaded sleeve 55 is pressed into a corresponding opening of the fluid guiding body 14. The threaded sleeve 55 has an internal thread into which the cap-shaped contact device 42 is screwed via a corresponding external thread.

[0092] exist Figure 16 In the embodiment shown in FIG. a of FIG. , the contact device 42 is locked against the fluid guiding body 14 via a nut 56. For this purpose, the cap-shaped contact device 42 has an external thread onto which the nut 56 can be screwed. The connecting device 43 is pressed onto the part of the contact device 42 that protrudes from the fluid guiding body 14. Figure 16 As shown in FIG. 2 b , the connecting device 53 may also be fixed to the fluid guiding body 14 via a nut 56 .

[0093] Apart from Figures 17 to 16In addition to the soldered connection between the contact device 42 and the electrical conductor 10 shown in FIG, the contact device 42 can also be arranged to be brought into electrical contact with the conductor 10 by mechanical deformation. For this purpose, in a first production step ( FIG. a), the contact device 42 can initially be clamped around the electrical conductor 10 in a pot-like manner with play and, in a subsequent deformation step ( FIG. b), pressed or snapped onto the electrical conductor 10 by means of a tool 50 in a circumferentially closed manner.

[0094] The present invention is not limited to the embodiments shown in the accompanying drawings. Therefore, the above description should not be regarded as restrictive, but rather as illustrative. The appended claims should be understood to mean that the recited features are present in at least one embodiment of the present invention. This does not exclude the presence of other features. Where the claims and the above description define a “first” feature and a “second” feature, such designation is used to distinguish between two features of the same type and does not define an order of precedence.

[0095] Reference Signs List

[0096] 1 stator

[0097] 2 motors

[0098] 3 Drivetrain

[0099] 4 Motor vehicles

[0100] 5 stator teeth

[0101] 6 Stator slots

[0102] 7 Groove sidewall

[0103] 8 Groove base

[0104] 9 Winding

[0105] 10 Conductors

[0106] 11 End face

[0107] 12 Cooling fluid

[0108] 13 Connect the main unit

[0109] 14 Fluid guide body

[0110] 15 base

[0111] 16 Inner sheath

[0112] 17 inner diameter

[0113] 18 inner diameter

[0114] 19 Fluid connections

[0115] 20 rotors

[0116] 21 outer diameter

[0117] 22 Air gap

[0118] 23 Connecting section

[0119] 24 connecting sections

[0120] 26 outer sheath

[0121] 27 Connecting groove

[0122] 31 connection groove

[0123] 35 Centering device

[0124] 36 Centering device

[0125] 38 seals

[0126] 40 Winding head

[0127] 41 contact section

[0128] 42 contact device

[0129] 43 Connecting device

[0130] 44 Inverter

[0131] 45 lateral part

[0132] 46 Insertion section

[0133] 47 Opening

[0134] 48 Opening

[0135] 49 slots

[0136] 50 tools

[0137] 51 contact section

[0138] 52 contact device

[0139] 53 Connecting device

[0140] 54 welding head

[0141] 55 threaded sleeve

[0142] 56 Nut

[0143] 57 Opening

[0144] 61 contact section

[0145] 62 contact device

[0146] 63 Connecting device

[0147] 67 Opening

Claims

1. A stator (1) for an electric machine (2), in particular for an electric machine in a drive train (3) of a motor vehicle (4), wherein: The stator (1) is designed in the form of a cylindrical ring with an inner diameter (17), in which a rotor (20) with an outer diameter (21) can be inserted, thereby forming a cylindrical air gap (22), and the stator (1) has a plurality of stator teeth (5), each stator tooth defining a corresponding stator groove (6), the stator groove being located between adjacent stator teeth (5) in the circumferential direction, extending in the radial direction, and extending through the stator (1) in the axial direction, and the stator groove comprising two groove side walls (7) and a groove base (8), in which a energizable winding (9) is inserted, the winding comprising a plurality of conductors (10), wherein the winding (9) leaves the stator (1) at at least a first end face (11), thereby forming a cylindrical first winding head (40), and wherein a cooling fluid (12) can flow through the stator (1) from the first end face (11), It is characterized by: The stator (1) has a cylindrical fluid-guiding body (14) through which the cooling fluid (12) can flow, and the fluid-guiding body at least partially surrounds the first winding head (40), wherein at least a first conductor (10a) of the winding head (40) has a first contact section (41), which extends out of the winding head (40) in the axial direction and at least partially passes through a corresponding first electrical contact device (42), which is arranged on the fluid-guiding body (14) in an electrically conductive manner, wherein the first electrical contact device (42) is connected to a first electrical connection device (43) in an electrically conductive manner, by means of which an electrical contact can be established between the first conductor (10a) and an inverter (44) that energizes the winding (9) via an outer side (45) of the fluid-guiding body (14) facing away from the cooling fluid (12).

2. The stator (1) according to claim 1, It is characterized by: The second conductor (10b) of the winding head (40) has a second contact section (51), which extends in the axial direction out of the winding head (40) and at least partially passes through a corresponding second electrical contact device (52), which is arranged on the fluid-guiding body (14) in an electrically conductive manner, wherein the second electrical contact device (52) is connected to a second electrical connection device (53) in an electrically conductive manner, by means of which an electrical contact can be established between the second conductor (10b) and an inverter (44) for energizing the winding (9) via an outer side (45) of the fluid-guiding body (14) facing away from the cooling fluid (12), and / or, The third conductor (10c) of the winding head (40) has a third contact section (61), which extends out of the winding head (40) in the axial direction and at least partially passes through a corresponding third electrical contact device (62), which is arranged on the fluid guiding body (14) in an electrically conductive manner, wherein the third electrical contact device (62) is connected to a third electrical connection device (63) in an electrically conductive manner, by means of which electrical contact can be established between the third conductor (10c) and an inverter (44) that energizes the winding (9) via an outer side (45) of the fluid guiding body (14) facing away from the cooling fluid (12).

3. The stator (1) according to claim 1 or 2, It is characterized by: The first electrical contact device (42) and / or the second electrical contact device (52) and / or the third electrical contact device (62) each have a material connection to the fluid-guiding body (14), in particular are bonded or overmolded.

4. Stator (1) according to one of the preceding claims, It is characterized by: The first electrical contact device (42) and / or the second electrical contact device (52) and / or the third electrical contact device (62) each have a conical insertion section (46) that widens in the direction of the first winding head (40).

5. Stator (1) according to one of the preceding claims, It is characterized by: The first electrical contact device (42) has a first opening (47), the first conductor (10a) penetrates the first opening and protrudes from the first opening (47) of the first electrical contact device (42), and / or, The second electrical contact device (52) has a second opening (57), the second conductor (10b) penetrates the second opening and protrudes from the second opening (47) of the second electrical contact device (52), and / or, The third electrical contact device (62) has a third opening (67), and the third conductor (10c) penetrates the third opening and protrudes from the third opening (67) of the third electrical contact device (62).

6. Stator (1) according to one of the preceding claims, It is characterized by: The cylindrical fluid guiding body (14) has an annular base (15), an inner jacket (16) axially extending from the base (15), and an outer jacket (26) axially extending from the base (15), wherein the inner jacket (16) has an inner diameter (18) greater than or equal to the outer diameter (21) of the rotor (20).

7. The stator (1) according to claim 6, It is characterized by: The first electrical contact device (42) and / or the second electrical contact device (52) and / or the third electrical contact device (62) are in each case arranged on the base (15) of the cylindrical fluid-guiding body (14).

8. A method for producing a stator for an electric machine (2), in particular for an electric machine in a drive train (3) of a motor vehicle (4), comprising the following steps: A cylindrical stator (1) with an inner diameter (17) is provided, in which a rotor (20) with an outer diameter (21) can be inserted, thereby forming a cylindrical air gap (22), and the stator (1) has a plurality of stator teeth (5), each stator tooth defining a corresponding stator groove (6), the stator groove being located between adjacent stator teeth (5) in the circumferential direction, extending in the radial direction, and extending through the stator (1) in the axial direction, and the stator groove comprising two groove side walls (7) and a groove base (8), wherein the stator groove ... having a plurality of stator teeth (5), each stator tooth defining a corresponding stator groove (6), the stator groove having a plurality of stator teeth (5), each stator tooth defining a corresponding stator groove (6), the stator groove having a plurality of stator teeth (5), each stator tooth defining a corresponding stator groove (6), the stator groove having a plurality of stator teeth (5) A energizable winding (9) is inserted into the stator (1), the winding comprising a plurality of conductors (10), wherein the winding (9) leaves the stator (1) at at least a first end face (11) to form a cylindrical first winding head (40), and wherein a cooling fluid (12) can flow through the stator (1) from the first end face (11), wherein at least a first conductor (10a) of the first winding head (40) has a first contact section (41) extending out of the winding head (40) in the axial direction, a cylindrical fluid-guiding body (14) is provided, through which the cooling fluid (12) can flow, wherein the first winding head (40) can be at least partially surrounded by the fluid-guiding body (14), a first electrical contact device (42) is arranged on the fluid-guiding body (14), through which the first contact section (41) of the first electrical conductor (10a) can at least partially pass in an electrically contacting manner, Arranging the fluid-guiding body (14) on the first winding head (40) so that the first contact section (41) and the first electrical contact device (42) are in electrical contact.

9. A fluid guiding body (14) for a stator (1) of an electric machine (2), wherein: The fluid guiding body (14) is designed to be cylindrical and a cooling fluid (12) can flow through the fluid guiding body, wherein a first electrical contact device (42) arranged on the fluid guiding body (14) can at least partially make electrical contact with a first conductor (10a) of a winding head (40) and is connected to a first electrical connection device (43) in an electrically conductive manner, by means of which an electrical contact can be established between the first conductor (10a) and an inverter (44) that energizes the winding (9) via an outer side (45) of the fluid guiding body (14) facing away from the cooling fluid (12).

10. An electric machine (2), in particular an electric machine in a drive train (3) of a motor vehicle (4), characterized in that The electric machine (2) comprises a stator (1) according to one of claims 1 to 7.

Images