WO2023006568A1

WO2023006568A1 - Stator assembly having efficient cooling, and electric machine having a stator assembly of this type

Info

Publication number: WO2023006568A1
Application number: PCT/EP2022/070469
Authority: WO
Inventors: Philip Dötschel; Timo Wehlen; Eckhardt LÜBKE; Ulrich Kehr; Alexander Strobel; Rico Zeiler
Original assignee: Zf Friedrichshafen Ag
Priority date: 2021-07-26
Filing date: 2022-07-21
Publication date: 2023-02-02
Also published as: DE102021208017A1

Abstract

The invention relates to a stator assembly (100, 200, 400, 500, 600, 700) for an electric machine (300), comprising a stator (10) with stator slots (10b) and wire windings (18) disposed in the stator slots (10b), wherein the stator (10) is embedded in a shell (1) made of a thermosetting resin, and wherein the stator (10) and the shell (1) are disposed in a housing (12) which surrounds the shell (1). According to the invention, a first cooling channel geometry (5a) is provided on an outer lateral surface (1a) of the shell (1) in order to form a first cooling channel (6a) running in the axial direction. The invention also relates to an electric machine (300), comprising a stator assembly (100, 200, 400, 500, 600, 700) of this type, and to a method for producing a stator assembly of this type.

Description

Stator arrangement with efficient cooling and electrical machine with such a stator arrangement

The invention relates to a stator arrangement for an electrical machine having a stator with stator slots and wire windings arranged in the stator slots, the stator being embedded in a casing made of a duroplast, and the stator and the casing being arranged in a housing enclosing the casing. The invention further relates to an electrical machine with such a stator arrangement and with a rotor. Ultimately, the invention also relates to a method for producing such a stator arrangement.

Generic stator assemblies are known from the prior art and are used in electrical machines, for example, in traction machines that are used to drive motor vehicles. In such Statoran regulations or electrical machines generated during the drive waste heat from power losses that must be dissipated from the electrical machine. These housings designed as a cooling jacket with cooling channels provided therein are known, for example, in which the waste heat is comparatively inefficient abge leads. However, since the basic aim is to build electrical machines as compactly as possible, with liquid cooling a strict seal between electrical components and the cooling liquid must be guaranteed and, in addition, essential components of the electrical machine are moved, more efficient internal liquid cooling systems are difficult to implement.

Due to the waste heat produced and the associated high temperatures in the electrical machine, materials which have a corresponding heat resistance were also preferably used in the past for the construction of an electrical machine. Therefore, inexpensive plastic materials that have limited heat resistance have been little or not used at all. In particular, mostly metal cast parts have been used as the housing. At the Fraunhofer Institute for Chemical Technology, an electrical machine with internal liquid cooling was developed under the project name "DEmiL - Directly cooled electric motor in plastic construction for traction applications". In this case, a stator arrangement described at the outset is used with a stator, the stator being spray-coated with a duroplast by means of a transfer molding process. The wire windings are designed with flat wire in order to achieve a high slot fill factor, so that there is sufficient installation space for cooling channels in the stator slots next to the wire windings. These cooling channels are formed by a suitably shaped tool with lances that engage in the stator slots. The stator can then be cooled with liquid by means of these cooling channels, so that sufficient heat can be dissipated to provide an inexpensive plastic housing without further cooling. The disadvantage is that the production of cooling channels in the stator slots is very complex and requires expensive tools that are prone to damage. Furthermore, the geometry to be produced by means of the transfer molding process is complicated and to this extent prone to the formation of defects. Cooling ducts in the stator slots are also associated with high pressure losses, depending on the duct cross section.

Against the background of the prior art described, it is an object of the invention to propose a cost-effective stator arrangement or a cost-effective electrical machine with efficient liquid cooling.

This object is achieved according to a first aspect of the invention with a Statoranord voltage according to claim 1. The object is also achieved according to a second aspect of the invention with an electrical machine according to claim 9 . Ultimately, the object is achieved according to a third aspect of the invention with a method according to claim 11. Advantageous configurations result from the subclaims.

A traction machine, for example, is understood here as an electrical machine. This can be formed, for example, as a synchronous or asynchronous machine. The invention relates in particular to electrical machines designed as internal rotors. Within the meaning of the invention, the entirety of the in understood the rotating parts of the electric machine. In particular, rotor laminations, the rotor shaft and balancing disks belong to the rotor.

A shell is understood to mean a layer of material on the surface of the stator, which is produced in particular by means of an injection molding process.

In a particularly preferred embodiment, the stator is completely covered by the casing and is completely sealed off from the environment by the latter. The stator has the basic shape of a cylindrical sleeve, with the sleeve corresponding to this basic shape. The shell is in particular on all surfaces of the stator and also fills out smaller interior spaces on their surface, but not the cylindrical space enclosed by the stator, which is provided for a rotor. In particular, the shell encloses exposed end windings of the stator winding at the axial ends of the stator, with the shell material also filling in between spaces between the wires of the end windings. In this embodiment, the casing is provided in such a way that no component of the stator is accessible from the outside and in particular cannot be reached by a liquid. The stator is thus encapsulated in the shell.

In a further embodiment, the shell partially covers the stator, so that, for example, part of the outer lateral surface of the stator is exposed. The shell then seals the stator in the areas in which it covers it from the environment. A separate seal is then provided for exposed areas, for example a flat seal, which is arranged between the shell and the housing or between the shell and an end shield. The exposed surfaces serve, for example, for direct torque support of the stator in the housing, for example by means of a press fit with which the housing sits on the upper surface of the stator. For example, in such an embodiment, the windings and in particular the winding heads are completely covered by the sheath.

Phases of the stator or contact ends of these phases can break through the shell and protrude from the shell. Openings provided for this purpose are preferably provided in such a way that no liquid can penetrate to the stator, for example by seals provided there, or by the breakthroughs are in liquid-free areas of the electrical machine.

The shell is preferably produced by an injection molding process, in which case an injection molding tool is designed in such a way that it forms a free space as a negative for the shell. The free space is then completely filled with a duroplast. The spraying process is particularly preferably a transfer molding process.

The duroplast preferably has good thermal properties, in particular high temperature resistance and good thermal conductivity. Furthermore, the thermoset preferably has good viscous properties before curing, in particular a low viscosity.

The housing encloses the shell or the stator and the shell. This is to be understood in such a way that the housing encloses the casing radially on the outside around the entire circumference at least over part of the axial length of the casing. In particular, the housing encloses the shell over its entire axial length around the entire circumference. The housing can also completely or partially enclose the shell on one axial end face or on both axial end faces, it being possible for the housing to have a multi-part design in the case of a two-sided design.

The outer surface of the casing, on which the radial direction is perpendicular, is understood to be the lateral surface of the casing.

According to the first aspect of the invention, a stator arrangement mentioned at the outset is characterized in that a first cooling channel geometry is provided on an outer lateral surface of the shell to form a first cooling channel running in the axial direction.

The axial direction here is the axial direction of the stator, which usually coincides with the axial direction of the entire electrical machine. The cooling channel is therefore on the lateral surface in the longitudinal direction, that is to say in the direction of the usually greatest extension of the casing from one end winding to the other end winding educated. A plurality of first cooling channel geometries are preferably provided for the formation of a plurality of cooling channels distributed around the circumference and formed parallel to one another. Depending on the performance requirements, all or some of these channels can also be connected in series with one another. An arrangement is preferred in which the cooling channels on the stator casing are all connected in parallel.

A coolant that runs through the first cooling channel absorbs heat directly at the stator and thus advantageously enables efficient cooling of the stator arrangement or an electrical machine formed therewith. Further cooling, in particular cooling provided in the area of the rotor of the electrical machine, can be dispensed with depending on the continuous power requirement. Depending on the continuous power requirement, the wire windings of the stator are also cooled sufficiently efficiently in part via the first cooling channel and do not have to be cooled separately, especially in the case of low cooling requirements. Furthermore, an embodiment of the housing from a cheap material that is not very heat-resistant is advantageously possible. According to the first aspect of the invention, the cooling channel is easy to manufacture. In addition, it is ensured that no cooling liquid reaches the electrical components of the stator. Due to the axial alignment of the first cooling channel, a coolant experiences a low pressure loss when flowing through the first cooling channel.

The cooling channel geometry preferably has a rectangular or at least partially round cross section. The cooling channel can also have cooling ribs, ie before cracks on the shell that protrude into the cooling channel.

In one embodiment, a coolant flows in and/or outflows to the first cooling channel radially through a corresponding through-opening in the housing. In a further embodiment, an inflow and/or outflow takes place in the axial direction on an end face of the housing, with the housing also having at least one passage opening for the inlet of the cooling medium on the corresponding end face or casing side, depending on the design of the housing. In further embodiments, inflow is radial and outflow is axial or vice versa. In one embodiment, the first cooling channel geometry is formed with a closed cross section within the shell. Such a geometry is produced, for example, with an injection mold that has axial lances that are surrounded by the thermoset during the injection process and then removed. The cooling channel is designed for efficient cooling on the outer lateral surface of the stator, with the cooling channels being closed so that no further sealing of the cooling channels has to be provided.

In a preferred embodiment, the first cooling channel geometry is formed on the outer lateral surface of the shell and forms the first cooling channel with the housing. In this way, the tool for forming the shell is simple in design and no internal geometries have to be formed in the shell. Meanwhile, the stator cooling is just as efficient due to the first cooling channel formed directly on the outer lateral surface.

The housing preferably forms the first cooling channel with the first cooling channel geometry by closing the first cooling channel geometry, which was previously open at least on one outer side, thus forming at least one side wall in the cross section of the first cooling channel. For this purpose, the housing is preferably designed to be smooth on its inner lateral surface in a simple manner, so that the geometry of the housing is very simple and it can be produced inexpensively. The housing can also have more complex geometries which, together with the first cooling duct geometry, form the first cooling duct. In such an embodiment, the housing forms, for example, a plurality of side walls or parts thereof of the first cooling channel. The housing is then preferably also produced by means of an injection molding process.

In a preferred embodiment, a second cooling channel geometry is provided on at least one end face of the shell to form a second cooling channel, with the second cooling channel being connected to the first cooling channel. In one embodiment, such a second cooling channel geometry is formed with a closed cross section within the shell. In a preferred embodiment, the second cooling channel geometry forms with the housing or another component a second cooling channel. Advantageously, the second cooling channel is arranged in the area of the winding heads and can absorb waste heat generated there directly. The electric machine is thus cooled more efficiently.

The second cooling channel geometry is particularly preferably designed in a spiral shape, so that the coolant circles the stator several times in order to flow along between the radially inner and the radially outer edge of a winding overhang. In this way, a particularly efficient cooling of the end winding or the end windings is created.

A further component is, for example, an end shield which is fastened to the housing at one axial end and has or forms a bearing mount for the rotor.

More preferably, in one embodiment, the shell is designed with a second cooling channel that projects radially inward beyond the stator, so that the second cooling channel is formed within the end windings and/or on axial end faces of a rotor arranged there. In this way, the cooling can be further improved.

With different load cases in the operation of an electrical machine, the main waste heat load occurs at different points. For example, the outer casing of the stator is preferably cooled in a first load case, depending on the speed, while in a second load case the end windings are preferably cooled. In one embodiment, coolant flows through the first and second cooling channel or areas with preference or as a secondary priority. For example, depending on the load, the flow direction of the coolant is reversed, with the coolant being colder on the inlet side than on the outlet side. Alternatively, the cooling channels have several inflow or outflow points, which are connected to one another depending on the load case, so that some areas of the cooling channels lie between the respective inflow and outflow and other areas do not.

It is particularly preferable for the shell between the cooling channel and the stator to be as thin-walled as the duroplastic material properties permit or as thin as possible. how it can be realized in the manufacturing process. In this way, the heat transfer between the stator and the cooling liquid has the highest possible heat transfer coefficient. At the same time, the shell is made of a duroplast with the highest possible coefficient of thermal conductivity.

In a further preferred embodiment, the stator has at least one depression or one projection on a surface area for torque support of the stator in the casing. In particular, the indentation or the projection expands in the axial direction, ie it is designed as a groove or rib. The shell forms a form fit in the circumferential direction with this indentation or this projection, so that the stator cannot rotate relative to the shell. Be preferably a plurality of depressions or projections distributed around the circumference formed on the stator.

In the same way, in a further embodiment, the sleeve has at least one depression or one projection on an outer lateral surface for torque support of the sleeve in the housing. In particular, this Vertie expands tion or this projection in the axial direction, so it is formed as a groove or rib. Such a cooling channel can be provided in a particularly simple manner on the outer lateral surface of the casing by extending the first cooling channel in an axial direction as well. A depression or a projection is formed, for example, by the tool having a corresponding projection or a corresponding depression. Twisting of the sleeve in the housing is prevented when the sleeve is arranged in the housing in such a way that the depression or the projection interacts with a corresponding counter-geometry of the housing. It can also be formed in particular as ribs on the shell, two projections between which a space for engaging a projection formed on the housing is formed, or on the housing two projections are formed in particular special as ribs, between which a space for engagement a projection formed on the shell. A plurality of indentations or projections distributed around the circumference are preferably formed on the casing. In a preferred embodiment, a seal is arranged on at least one surface of the sleeve to seal the sleeve relative to the housing or another component. In this way, the first and/or the second cooling duct is sealed off from other components of the electrical machine. For example, an O-ring is arranged on the outer surface of the shell, which rests against the Ge housing. Alternatively or additionally, an O-ring is also arranged, for example, on a front side of the shell, which bears against a bearing plate. As an alternative or in addition, an O-ring or a shaft sealing ring is also arranged, for example, on an inner lateral surface of the casing, which bears against the rotor, the housing or another component.

In a further preferred embodiment, phases of the stator are passed through the casing. Connections of the windings or of groups of windings are understood here as phases. The passage is preferably designed in such a way that no liquid can get through between the phase and the shell, for example by providing a seal there, for example a silicone seal. In addition, the phase ends, ie the part of the phases protruding from the shell, are arranged in an area in which no liquid is conducted. For example, this area is separated by one or more seals from other areas in which liquid is conducted, such as the cooling channels.

Alternatively, a connection element is provided on phases of the stator, the connection element being embedded in the casing. Such a connecting element is, for example, a terminal plate on which connections for cables or plugs are provided. The connecting element is then embedded with the stator in the casing and preferably sealed by it, with the connections being exposed in such a way that lines can be connected to them from the outside, in particular by means of plugs. The connections can remain free during the manufacture of the shell or be subsequently exposed, for example with a machining process. The connections are in an area in which no liquid is routed. The second aspect of the invention relates to an electrical machine with a stator arrangement described above and with a rotor. Such an electrical machine advantageously has the advantages described above.

In one embodiment, a cover is arranged on the end face of the rotor, which at least partially protrudes beyond the rotor in the radial direction, with a third cooling channel geometry being provided in the cover to form a third cooling channel, and with the third cooling channel being connected to the first and/or the second cooling channel connected is. The third cooling channel geometry is particularly preferably formed on an end face of the cover and forms the third cooling channel with the housing or a further component. In this way, the casing can be designed in such a way that the rotor can be installed by pushing it in in the axial direction, with the cover then being arranged over the end face of the rotor. The third cooling duct then ensures efficient cooling of the rotor and the end winding on this side.

The third aspect of the invention relates to a method for producing a stator arrangement as described above, wherein a stator is enclosed by an at least two-part tool and is centered in the tool so that there is a free space between the stator and the tool, and the free space is filled with a duroplast by means of an injection molding process to form a shell covering all or part of the stator, removing the tool and placing the stator with the shell in a housing surrounding the shell.

According to the third aspect of the invention, the tool according to the invention has projections and/or indentations on a surface corresponding to the outer lateral surface of the shell, such that a first cooling channel geometry is formed on an outer lateral surface of the shell when the injection molding process is carried out.

Enclosed is understood to mean that the stator is enclosed in the tool. In particular, the tool has a central cylinder which engages in the stator and, in addition, a sleeve which encompasses the stator, and end parts which terminate in the cylinder and the sleeve in the axial direction. This The basic geometry is modified in such a way that projections and recesses are provided where, for example, winding heads or a connecting element are or will be encompassed. The tool also has geometries on its surfaces as a negative for the formation of cooling channel geometries and indentations or projections for torque support for corresponding designs of the stator arrangement.

In one embodiment, the tool consists of two or more parts, at least one part of which is positioned on the stator in the axial direction. In a further embodiment, at least one part, for example a half-shell, is positioned on the stator in the radial direction. In a further embodiment, the tool consists of several parts, which are positioned partly radially and partly axially on the stator.

As described above, the first cooling channel geometry is either one that forms the first cooling channel itself or one that forms the first cooling channel together with the housing.

In one embodiment, the spraying process is a transfer molding process. In such a molding or a certain number of tablets of the starting material is placed in a cavity formed in the tool. This cavity is connected to the free space via channels. The molded part or the tablets are then liquefied and pressed via the channels into the free space by means of a stamp at comparatively high pressure and high temperatures. The starting material then hardens under the existing pressure in the free space. Advantageously, there are no backflows with this method and it is suitable for forming even the smallest geometrical details of the shell. The process can also be followed by post-curing of the thermoset.

The tool has centering means which bear against the stator at at least two points in order to center it with respect to the tool, ie to position it in the radial, axial and circumferential directions. In one embodiment, the centering means remain on the stator during the injection molding process, with a shell then being formed is formed, which does not completely cover or seal the stator. This is provided for example when the stator is intended to be supported directly in the housing.

In a preferred embodiment, the centering means are removed while the free space is being filled in such a way that the space freed up by the centering means when they are removed is filled with duroplast. The centering means are then, for example, pins that press radially onto the stator and are pulled away from the stator in the radial direction as soon as the stator is centered in the tool by the duroplast that has already been injected, but before it has hardened. The duroplast then forms an uninterrupted shell in which material is also formed where the pins were previously arranged. In this way, centering of the stator is ensured, while an uninterrupted, sealed envelope can be created.

In a preferred embodiment, the tool has through-openings through which the phases of the stator or connections connected to the phases are passed, the clear surface of the through-openings remaining after the phases or the connections have been passed being closed by means of a sealant. This sealant, such as a silicone cushion, is preferably located before, in or after the recess in the tool before the phases are carried out. Alternatively, the sealant can also be applied later.

The thermoset is thus prevented by the sealing means from escaping at the through-openings during the injection molding process, but encloses the phases or terminals in a sealed manner. Contact ends of the phases or terminals are then accessible from outside the shell and, in the case of the phases, for example, are provided with a terminal element that is then arranged outside the shell.

The diameter of the through-openings can be significantly larger than the diameter of the phases or connections, so that after the phase has been carried out sen or connections there is enough space to insert a sealant. Alternatively or additionally, the through-openings can also have depressions, for example pockets, on the inside or outside, in which a sealant can be arranged.

In a further embodiment of the method, phases of the stator are first embedded in the shell and then exposed. This is done, for example, by means of a machining process. Then no through opening has to be provided in the tool.

The invention is described below with reference to figures which show different embodiments of the invention, identical or similar elements being provided with the same reference symbols. In detail shows:

1 shows a perspective view of a stator arrangement without a housing according to the first aspect of the invention in a first embodiment;

2 shows a perspective view of a stator arrangement without a housing according to the first aspect of the invention in a second embodiment;

3 shows a cross-sectional illustration of an electrical machine according to the second aspect of the invention in a preferred embodiment;

4 shows a plan view of a stator arrangement without a housing according to the first aspect of the invention in a third embodiment;

5 shows a section of a cross-sectional illustration of a stator arrangement without a housing according to the first aspect of the invention in a fourth embodiment;

6 shows an exploded view of a stator with a two-part tool for carrying out a method according to the third aspect of the invention; 7 shows a section of a cross-sectional illustration of a stator arrangement without a housing according to the first aspect of the invention in a fifth embodiment

8 shows a cross-sectional illustration of a three-part tool for carrying out a method according to the third aspect of the invention; and

9 shows a detailed view of two passage openings in a tool part with phases carried out in two different embodiments.

1 shows a stator arrangement 100 without a housing, the stator arrangement 100 having a stator embedded here in a casing 1 and thus covered, and the casing 1 . The shell 1 has an outer lateral surface 1a, a first end face 1b, an inner lateral surface 1c and a second end face 1d which is covered here. Below the outer lateral surface 1a and the inner lateral surface 1c, the respective lateral surfaces of the stator are arranged, the stator having winding heads on the front side, one of which is below the front side 1b of the shell 1. Furthermore, a formation 1e is formed on the shell 1, which encloses a connection element hidden underneath. Only connections 2 can be recognized from the connection element.

On its outer surface 1a, the shell 1 has projections 3a, 3b arranged in pairs, which extend in the axial direction along the shell, with a depression 4 being formed between each pair of projections 3a, 3b, which serves to there engages a projection of a housing, not shown, to ensure a torque support and centering between the case 1 and the housing.

Between the pairs of projections 3a, 3b, first cooling channel geometries 5a are formed in the axial direction, which form a first cooling channel 6a extending in the axial direction with the housing (not shown) that spans them for liquid cooling of the stator. For this purpose, a first O-ring 7a is provided as a seal at one axial end of the projections 3a, 3b at the level of the winding head there, and on the side of the first O-ring 7a facing the end face 1b Cooling liquid passed through a radial opening in the housing into the cooling channel 6a. The cooling liquid then flows through the first cooling channel 6a in the direction of the end face 1b of the shell 1.

A second cooling channel geometry 5b is formed on the end face 1b, which forms a second cooling channel 6b running spirally from radially outside to radially inside with the housing lying there. An outlet for the coolant is provided radially on the inside of the housing. A second O-ring 7b is provided on the inner lateral surface 1c, which seals the second cooling channel 6b in relation to a rotor (not shown).

FIG. 2 shows a stator arrangement 200, which essentially corresponds to the stator arrangement 100, with no connection element being provided on the stator in this embodiment and accordingly a formation 1e not being formed on the casing 1. FIG.

Fig. 3 shows an electrical machine 300 with a stator assembly 400 with a stator 10 on which winding heads 11a, 11b are formed, a shell 1 and a housing 12. The electrical machine 300 also includes a rotor 13, comprising balancing disks 13a on its axial ends, which is net angeord on a shaft 14, and a cover 15 on the face side of the rotor 13. At a second end formed there 1 d of the shell 1, the shell 1 is covered by a bearing plate 16.

A first cooling channel geometry 5a is formed on the outer lateral surface 1a of the shell 1a and, together with the housing 12, forms a first cooling channel 6a.

On the first end face 1b of the shell 1, a second cooling channel geometry 5b is formed, which forms a second cooling channel 6b with the housing 12, which is connected to the first cooling channel 6a. A third cooling channel geometry 5c is formed directly below in the cover 15, which forms a third cooling channel 6c with the housing 12, which is connected to the second cooling channel 6b (not shown in detail here). On the second end face 1d of the shell 1 is also a fourth cooling chamber nalgeometrie 5d formed, which forms a fourth cooling channel 6d with the bearing plate 16, which is connected to the first cooling channel 6a and extends to below the first end winding 11a. The individual components are each fluidically sealed from one another by means of seals 17a, which are designed in particular as O-rings, in order to seal off the cooling channels from the outside and/or from other parts of the electrical machine. The shaft 14 is, however, not shown here, mounted on the one hand in the housing 12 and on the other hand in the bearing plate 16 .

FIG. 4 shows a stator arrangement 500 without a housing 12 in a plan view. In this case, the outer jacket surface of the stator 10 is exposed in a central region, with a first cooling channel geometry 5a being formed in the casing 1 next to this exposed surface. The central area is surrounded by a seal 17b, which is designed in particular as a flat seal and seals against the housing 12. The exposed area is provided so that the housing 12 bears against the outer lateral surface of the stator 10 by means of a press fit, with a torque support of the stator 10 in the housing 12 being realized via the press fit.

5 shows a sectional view through a stator arrangement 600 in a further embodiment without the housing 12 shown. The stator 10 has stator laminations 10a in which stator slots 10b are formed, in which wire windings 18 in turn run. The stator laminations 10a also have depressions 19 on an outer surface, in which material of the shell 1 is formed. In this way, the stator 10 is supported in the casing 1 in a torque-proof manner. A direction of the force acting between the shell 1 and the stator laminations 10a is indicated by a force arrow.

FIG. 6 shows a stator 10 with a tool 20 arranged around it, which consists of a first tool shell 20a and a second tool shell 20b. The first tool shell 20a has a cylindrical projection 21 and a front shoulder 22 which engages in the interior of the stator 10. The second tool shell 20b is designed as a hollow cylinder and encloses the stator 20. It also has an end wall, which cannot be seen here, on the outer end face. Between the tool shells 20a, 20b, or the tool 20, when this is closed, and the stator 10 creates a free space, which is then filled in a transfer molding process with a thermoset to form the shell 1 out.

Fig. 7 and Fig. 8 show another embodiment of a stator assembly 700 in a sectional view and a tool 23 for producing such a stator assembly 700. On the stator 10, the shell 1 is formed only in the first peripheral sections 24a, while in the second peripheral sections 24b the outer surface of the stator 10 is exposed. In these second peripheral sections 24b, the stator 10 is directly connected to the housing 12 for torque support. First cooling channel geometries 5a are formed in the shell 1 and form a closed first cooling channel 6a. The first cooling channel 6a is thus formed without the housing 12 being involved.

FIG. 8 shows a tool 23 for forming such a shell 1, which consists of a first tool shell 23a, a second tool shell 23b and a third tool shell 23c. The tool shells 23a and 23b essentially correspond to the tool shells 20a and 20b in FIG. 6, with the second tool shell 23b not completely encompassing the stator 10 on the outside. An outer wall for the tool 23 is instead formed by the third tool shell 23c. As an alternative to the illustration in FIG. 8, the tool shell 23c can also be made in two parts. The first tool shell 23a also has lances 25, by means of which the cooling channel geometries 5a or the cooling channels 6a according to FIG. 7 are formed. Furthermore, projections 26 are provided on the second tool shell 23b in order to form cooling channel geometries on the shell 1 below the first end winding 11a, approximately as shown in FIG.

Fig. 9 shows a detailed view of through-openings 27a, 27b in two under different geometries in a tool end face, for example in a second tool shell 20b according to FIG. The clear areas remaining between passage openings 27a, 27b and phases 28 can be rau ms be closed with Duroplast by a seal, not shown, such as an elastomer or silicone seal.

reference sign

Shell a outer surface of the shell b first face of the shell c inner shell of the shell d second face of the shell e shape

Terminals a boss b boss

Deepening a first cooling channel geometry b second cooling channel geometry c third cooling channel geometry d fourth cooling channel geometry a first cooling channel b second cooling channel c third cooling channel d fourth cooling channel a first O-ring b second O-ring 0 stator 0a stator lamination 0b stator slot 1a first winding head 1b second winding head 2 housing 3 rotor 3a balancing discs 4 shaft 5 cover 6 end shield a Gasket b Gasket

wire wraps

deepening

Tool a first tool shellb second tool shell cylindrical projection shoulder tool a first tool shellb second tool shellc third tool shella first peripheral portionb second peripheral portions

lance

Projection a through hole b through hole

Phase 0 stator assembly 0 stator assembly 0 electric machine 0 stator assembly 0 stator assembly 0 stator assembly 0 stator assembly

Claims

patent claims

1. Stator arrangement (100, 200, 400, 500, 600, 700) for an electrical machine (300) with a stator (10) with stator slots (10b) and in the stator slots (10b) is arranged wire windings (18), wherein the Stator (10) in a shell (1) is embedded from a thermoset, and wherein the stator (10) and the shell (1) in a shell (1) enclosing the housing (12) are arranged, characterized in that on a outer lateral surface (1a) of the shell (1) has a first cooling channel geometry (5a) for forming a first cooling channel (6a) running in the axial direction.

2. Stator arrangement (100, 200, 400, 500, 600, 700) according to claim 1, wherein the first cooling channel geometry (5a) on the outer lateral surface (1a) of the shell (1) is formed and the first cooling channel geometry (5a) with the housing (12) forms the first cooling channel (6a).

3. Stator arrangement (100, 200, 400, 500, 600, 700) according to claim 1 or 2, wherein a second cooling channel geometry (5b, 5d) is provided on at least one end face (1b, 1d) of the shell (1), wherein the second cooling channel geometry (5b, 5d) forms a second cooling channel (6b, 6d) with the housing (12) or a further component, and wherein the second cooling channel (6b, 6d) is connected to the first cooling channel (6a).

4. Stator arrangement (100, 200, 400, 500, 600, 700) according to one of the preceding claims, wherein the stator (10) has at least one recess (19) or a projection for torque support of the stator (10) on a lateral surface the shell (1) has.

5. Stator arrangement (100, 200, 400, 500, 600, 700) according to any one of the preceding claims, wherein the shell (1) on an outer lateral surface (1a) at least one depression (4) or a projection (3a, 3b) for supporting the torque of the sleeve (1) in the housing (12).

6. Stator arrangement (100, 200, 400, 500, 600, 700) according to one of the preceding claims, wherein at least one surface (1a, 1b, 1c, 1d) of the casing (1) has a seal (7a, 7b, 17a, 17b) for sealing the casing (1) relative to the housing (12) or another component.

7. stator assembly (100, 200, 400, 500, 600, 700) according to any one of the preceding claims, wherein phases (28) of the stator (10) through the shell (1) are Durchge leads.

8. Stator arrangement (100, 200, 400, 500, 600, 700) according to one of claims 1 to 6, wherein phases (28) of the stator (10) is provided with a connection element, the connection element being embedded in the casing (1). is.

9. Electrical machine (300) with a stator arrangement (100, 200, 400, 500, 600, 700) according to one of the preceding claims and with a rotor (13).

10. Electrical machine (300) according to claim 9, wherein the front side of the rotor (13) has a cover (15) which at least partially projects beyond the rotor (13) in the radial direction, wherein the cover (15) has a third cooling channel geometry (5c) is provided to form a third cooling duct (6c), and wherein the third cooling duct (6c) is connected to the first and/or the second cooling duct (6a, 6b).

11. A method for producing a stator assembly (100, 200, 400, 500, 600, 700) according to any one of claims 1 to 8, wherein

- a stator (10) is surrounded by an at least two-part tool (20, 23) and is centered in the tool (20, 23) so that there is a free space between the stator (10) and the tool (20, 23),

- the free space is filled with a duroplast by means of an injection molding process in order to form a casing (1) in which the stator (10) is embedded,

- the tool (20, 23) is removed and the stator (10) with the casing (1) is arranged in a casing (12) surrounding the casing (1), characterized in that the tool (20, 23) has projections and/or indentations on a surface corresponding to the outer lateral surface (1a) of the casing (1), so that when the spraying process is carried out on an outer lateral surface (1a) the shell (1) is formed with a first cooling channel geometry (5a) to form a first cooling channel (6a).

12. The method according to claim 11, wherein the spraying process is a transfer molding process.

13. The method of claim 11 or 12, wherein for centering the stator (10) on the tool (20, 23) centering means are provided, and wherein the Zentriermit tel are removed during the filling of the free space, such that the by the centering means when Remove freed space filled by thermoset.

14. The method according to any one of claims 11 to 13, wherein the tool (20, 23) has through-openings (27a, 27b) through which phases (28) or connected to the pha sen terminals of the stator (10) are performed, and wherein the clear surface of the passage openings (27a, 27b) remaining after the phases (28) or the connections have been carried out are closed by means of a sealant.

15. The method according to any one of claims 11 to 13, wherein phases (28) of the Sta tor (10) are first embedded in the shell (1) and then exposed who the.