An electric machine, in particular for a motor vehicle

Abstract

The invention relates to an electric machine (1), in particular for a motor vehicle. The electric machine comprises a rotor (3) and a stator (2), wherein the rotor is rotatable about a rotational axis (D) defining an axial direction (A) of the electric machine (1); the stator has an electrically conductive stator winding (6). Furthermore, the electric machine (1) comprises at least one cooling channel (10) through which a coolant (K) can flow, preferably a plurality of such cooling channels (10), for cooling the stator winding (6). The stator (2) has stator teeth (8) extending in the axial direction (A), which are arranged at a distance from one another in the circumferential direction (U) of the rotor (3) and carry the stator winding (6). Furthermore, at least one cooling channel (10) and at least one stator winding (6) are arranged in at least one intermediate space (9) formed in the circumferential direction (U) between two adjacent stator teeth (8, 8a, 8b). According to the invention, a plastic (11) for transferring heat from the stator winding (6) to the cooling channel (10) is arranged in the intermediate space (9).

Description

Field of the Invention

[0001] The present invention relates to an electric machine, in particular an electric machine for a motor vehicle, and to a vehicle having such an electric machine. Background Art

[0002] This type of electric machine can generally be an electric motor or a generator. The electric machine can be designed as an outer rotor or an inner rotor.

[0003] For example, a machine of this type is known from U.S. Patent No. 5,214,325. It includes a housing surrounding an internal space and having a shroud that circumferentially surrounds and radially defines the internal space along the housing. A rear wall axially defines one side of the internal space in the axial direction, and a front wall axially defines the other side of the internal space in the axial direction. The stator of the electric machine is firmly connected to the shroud. The rotor of the electric machine is arranged in the stator, wherein the rotor shaft of the rotor is rotatably mounted on the front wall by a front shaft of a bearing.

[0004] The stator of a conventional electric machine typically includes a stator winding that is energized during operation of the electric machine. During this process, heat is generated, and this heat must be dissipated to avoid overheating and related damage or even destruction of the stator. Additionally, from conventional electric machines, it is known that they are equipped with cooling means for cooling the stator, in particular for cooling the stator winding. Such cooling means include one or more cooling channels through which a coolant flows, and the cooling channels are arranged near the stator winding in the stator. By transferring heat from the stator winding to the coolant, the heat of the stator can be dissipated.

[0005] It has proven disadvantageous that effective heat transfer from the stator to the coolant flowing through the respective cooling channels is only associated with high structural costs. However, this has an adverse effect on the production cost of the electric machine. Summary of the Invention

[0006] Accordingly, it is an object of the present invention to provide an improved embodiment for an electric machine, in which this disadvantage is largely or even completely eliminated. In particular, the present invention will present an improved embodiment for an electric machine, characterized in that the cooling of the stator winding of the stator is improved.

[0007] This object is solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent patent claims.

[0008] Therefore, the basic idea of the present invention is that the stator winding of the electric machine and the cooling channels through which the coolant flows are embedded together using plastic, and the plastic is used to cool the stator winding, which generally has electrical insulation and heat conduction characteristics. Therefore, on the one hand, the plastic can be used as a heat transfer medium for transferring heat from the stator winding to the coolant flowing through the cooling channels, and on the other hand, it can be used as an electrical insulator for the stator winding. Therefore, particularly good heat transfer is generated between the stator winding and the coolant guided through the cooling channels. This is especially the case if plastic with a high thermal conductivity is used. In addition, by using plastic with electrical insulation characteristics, it can be ensured that the stator winding to be cooled does not have an unwanted electrical short circuit due to the plastic passing through the cooling channels. In addition, it is ensured that when the coolant flows through the cooling channels, the generally conductive coolant is electrically insulated from the cooling channels of the stator winding. In addition, the stator teeth, which are part of the stator, can also be electrically insulated from the stator winding by plastic.

[0009] Compared with traditional cooling devices, by means of the plastic that is essential for the present invention, the direct thermal coupling of the cooling channels, the coolant and the stator winding to be cooled results in particularly effective cooling of the stator winding. Therefore, even when a large amount of heat is generated in the stator, for example, during high-load operation of the electric machine, it can thus be ensured that the waste heat generated can be dissipated from the stator. Therefore, damage or even destruction of the electric machine due to overheating of the stator can be avoided.

[0010] According to the present invention, an electric machine, especially for a motor vehicle, includes a rotor that can rotate about a rotation axis defining the axial direction of the electric machine. In addition, the electric machine includes: a stator having a conductive stator winding; and at least one cooling channel through which a coolant can flow to cool the stator winding. The stator has stator teeth extending in the axial direction, and the stator teeth are arranged at a certain distance from each other in the circumferential direction of the rotor and carry the stator winding. At least one cooling channel and at least one stator winding are arranged in at least one intermediate space formed between two adjacent stator teeth in the circumferential direction. According to the present invention, plastic for transferring heat from the stator winding to at least one cooling channel is arranged in the intermediate space.

[0011] Therefore, the plastic is preferably designed to be heat-conductive. Advantageously, the plastic can also be designed to be electrically insulating, that is, made of an electrically insulating plastic material.

[0012] According to a preferred embodiment, the plastic is at least partially arranged on the first surface portions of two adjacent stator teeth defining the intermediate space. Preferably, the cooling channel and the stator winding are electrically insulated from the stator teeth respectively and are thermally connected to each other through the plastic.

[0013] According to another preferred embodiment, the stator includes a stator body, and stator teeth project radially inwards from the stator body. In this embodiment, and in particular such that it can be combined with the above embodiments, plastic is arranged on a second surface portion of the stator body, and the second surface portion defines an intermediate space radially internally.

[0014] Particularly preferably, the plastic is arranged on all first surface portions of two stator teeth that define the intermediate space, that is to say, both in the circumferential direction of the relevant intermediate space and in the radial direction of the relevant intermediate space. In this way, an undesired electrical connection between the conductive material of the stator winding and the equally conductive stator teeth can be prevented.

[0015] According to an advantageous refinement, the plastic arranged on the first surface portion forms an electrically insulating layer, and the electrically insulating layer covers the first surface portions of two adjacent stator teeth that define the intermediate space. Such an insulating layer made of plastic is particularly easy to manufacture, for example by means of an injection molding process.

[0016] Cooling channels are advantageously arranged in the region of the radially internal end of the intermediate space. In this way, a particularly large construction space can be obtained for arranging the stator winding in the intermediate space. Alternatively or additionally, it is conceivable to arrange cooling channels in the region of the radially external end of the intermediate space.

[0017] In another preferred embodiment, the plastic forms at least one phase insulator, and the at least one phase insulator is arranged in the intermediate space and divides the intermediate space into a radially internal sub-space and a radially external sub-space. In this way, conductor elements of the stator winding that are electrically insulated from each other can be arranged in the two sub-spaces. This in turn makes it possible to assign two different electrical phases that must be electrically isolated from each other to two conductor elements that are electrically insulated from each other. It is conceivable that, in a refinement of the present invention, a plurality of such phase insulators are also arranged in the intermediate space. Appropriately, the value of the diameter measured radially of the phase insulator made of plastic is between 1 mm and 3 mm.

[0018] The phase insulator can advantageously extend in the circumferential direction and connect two insulating layers to each other, and the two insulating layers are arranged on adjacent stator teeth and are made of plastic. In this way, the two sub-spaces formed are completely defined by plastic that is preferably electrically insulating.

[0019] According to an advantageous refinement, at least one stator winding arranged in the intermediate space comprises at least one first conductor element and at least one second conductor element. According to this refinement, the two conductor elements are arranged at a distance from one another in the intermediate space, particularly preferably in the radial direction. The first conductor element can be part of a first electrical phase and the second conductor element is accordingly part of a second electrical phase of the stator. The first conductor elements are advantageously arranged in a radially inner sub-space and are electrically connected to one another for connection to a common first phase of the power supply. In this refinement, the second conductor elements are arranged in a radially outer sub-space and are electrically connected to one another for connection to a common second phase of the power supply.

[0020] Advantageously, in a cross-section perpendicular to the axial direction, it is essential for the invention that an electrically insulating and thermally conductive plastic surrounds at least one first conductor element and, alternatively or additionally, at least one second conductor element. Preferably, this applies to all first conductor elements or to all second conductor elements.

[0021] Particularly advantageously, the first conductor elements and, alternatively or additionally, the second conductor elements are designed as winding bars made of a conductive material.

[0022] According to an advantageous refinement, in a cross-section perpendicular to the axial direction, at least one winding bar can have a rectangular geometry with two narrow sides and two wide sides. This particularly preferably applies to all winding bars of the stator winding.

[0023] According to a particularly preferred embodiment, at least one first conductor element is electrically insulated from at least one second conductor element by means of plastic. Particularly preferably, the first conductor element is electrically insulated from the second conductor element by a phase insulator which separates the radially inner sub-space from the radially outer sub-space.

[0024] In another preferred embodiment, the plastic forms a protective coating in a cross-section perpendicular to the axial direction, which protective coating is arranged in the intermediate space and at least partially, preferably completely, defines or surrounds a cooling channel. "Defines" particularly means that the cooling channel does not require any further definition, for example in the form of a tubular body. "Protective coating" particularly means that an additional definition, for example in the form of said tubular body, can be arranged for the cooling channel. This protective coating can prevent the coolant, which is usually conductive and is guided through the cooling channel, from coming into contact with the stator winding or the conductive stator teeth also arranged in this intermediate space, thus preventing an electrical short circuit.

[0025] According to an advantageous refinement, the protective coating defines cooling channels radially inwardly and alternatively or additionally radially outwardly in a cross section perpendicular to the axial direction. This provides electrical insulation between the cooling channels or the coolant guided through the cooling channels and the stator winding radially outside or radially inside the cooling channels arranged in the intermediate space.

[0026] According to another advantageous refinement which can be combined with the abovementioned refinement, the protective coating defines cooling channels in the circumferential direction in a cross section perpendicular to the axial direction. In this way, electrical insulation between the cooling channels or the coolant guided through the cooling channels and the conductive stator teeth is ensured.

[0027] Particularly advantageously, another cooling channel can be arranged, especially in the region of the radially outer end of the intermediate space. In this way, the cooling of the stator winding can be significantly improved.

[0028] In another preferred embodiment, plastic forms another protective coating which is arranged in the intermediate space and at least partially, preferably completely, defines or surrounds another cooling channel.

[0029] According to another advantageous refinement, in a cross section perpendicular to the axial direction, another protective coating defines another cooling channel radially inwardly and alternatively or additionally radially outwardly. By means of this another protective coating, electrical insulation between the another cooling channel or the coolant guided through the another cooling channel and the stator winding radially outside or radially inside the another cooling channel arranged in the intermediate space is ensured.

[0030] According to another advantageous refinement which can be combined with the abovementioned refinement, another protective coating defines another cooling channel in the circumferential direction in a cross section perpendicular to the axial direction. In this way, electrical insulation between the another cooling channel or the coolant guided through the another cooling channel and the conductive stator teeth is ensured.

[0031] Advantageously, the cooling channels arranged in the region of the radially inner end are arranged in a radially inner sub-space formed by a phase insulation part of plastic. Alternatively or additionally, the cooling channels arranged in the region of the radially outer end are arranged in a radially outer sub-space formed by a phase insulation part of plastic. In this way, by transferring heat to the coolant guided through the respective cooling channels, the conductor elements of the radially inner and radially outer stator windings arranged in the intermediate space can be effectively cooled.

[0032] According to another preferred embodiment, a gap is at least partially formed between at least two conductor elements and alternatively or additionally between at least one conductor element and an electrically insulating layer, which electrically insulating layer is arranged on a first surface portion of the stator tooth and / or on a second surface portion of the stator body. In this embodiment, the plastic according to the invention forms a gap filler, with which the gap is at least partially and preferably completely filled.

[0033] According to another preferred embodiment, the plastic may comprise an electrically insulating plastic compound in which the stator winding is embedded.

[0034] Advantageously, the intermediate space may have a trapezoidal geometry, preferably a rectangular geometry, in a cross-section perpendicular to the axial direction. The trapezoidal or rectangular geometry allows at least one cooling channel and a large number of conductor elements or stator windings to be arranged in the respective intermediate space.

[0035] According to a preferred embodiment, the plastic arranged on the first surface portion of the stator tooth is formed of a first electrically insulating plastic material. Alternatively or additionally, in this embodiment, the plastic forming at least one phase insulation is formed of a second plastic material. Furthermore, the plastic forming the first protective coating and alternatively or additionally, the plastic forming another protective coating may be formed of the second plastic material or alternatively of a third plastic material.

[0036] According to an advantageous refinement, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials are the same material. In an alternative further refinement, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may be different materials.

[0037] Suitably, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may consist of or include such a thermoplastic. The first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may also advantageously consist of or include such a thermosetting plastic.

[0038] Advantageously, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may have the same thermal conductivity. Alternatively or additionally, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may have different thermal conductivities.

[0039] Advantageously, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may be the same material. Similarly, the first and alternatively or additionally, the second and alternatively or additionally, the third plastic materials may also be different materials.

[0040] According to a particularly preferred embodiment, at least one stator winding is part of a distributed winding.

[0041] According to a preferred embodiment, the thermal conductivity of the plastic, in particular of the first and alternatively or additionally, the second and alternatively or additionally, the third plastic material is at least 0.5 W / mK, preferably at least 1 W / mK.

[0042] In another preferred embodiment, the intermediate space is formed by means of plastic such that there are substantially no gaps.

[0043] In a particularly easily implementable embodiment, only a single cooling channel is provided in the intermediate space, i.e., there is no second cooling channel.

[0044] According to an advantageous refinement, the electric machine includes a coolant distribution chamber and a coolant collection chamber arranged at an axial distance from the coolant distribution chamber. The coolant distribution chamber is in fluid communication with the coolant collection chamber via at least one cooling channel through which the coolant can flow. Preferably, a plurality of such cooling channels are arranged between the coolant distribution chamber and the coolant collection chamber.

[0045] According to a preferred embodiment, the coolant distribution chamber for thermal coupling with the stator winding, and alternatively or additionally, the coolant collection chamber can be arranged at least partially in the plastic, which is essential for the present invention. In this case, the plastic consists of an electrically insulating plastic material. This enables particularly good heat transfer between the coolant distribution chamber and / or the coolant collection chamber and the stator winding, such that the coolant distribution chamber and / or the coolant collection chamber can also be used to directly absorb heat from the stator winding.

[0046] The electrically insulating plastic particularly preferably at least partially defines the coolant distribution chamber and, alternatively or additionally, defines the coolant collection chamber for thermal coupling with the stator winding.

[0047] The invention also relates to a vehicle, in particular a motor vehicle having the electric machine described above. Thus, the above advantages of the electric machine also apply to the vehicle according to the invention.

[0048] Other important features and advantages of the invention result from the dependent claims, the drawings, and the associated description based on the drawings.

[0049] It goes without saying that, without departing from the scope of the invention, the above features and the features to be described below can be used not only in the respective specified combinations, but also in other combinations or individually. Description of the Drawings

[0050] Preferred embodiments of the invention are shown in the drawings and are explained in more detail in the following description.

[0051] Schematically shown in each case:

[0052] Figure 1 An example of an electric machine according to the invention is shown in a longitudinal section along the rotational axis of the rotor,

[0053] Figure 2 The stator of the electric machine according to is shown in a cross-section perpendicular to the rotational axis of the rotor, Figure 1 of the electric machine,

[0054] Figure 3 Shows Figure 2 a detailed view of the stator of in the region of the intermediate space between two circumferentially adjacent stator teeth,

[0055] Figure 4 Shows an improvement according to the example of, Figure 3 which has an additional second cooling channel,

[0056] Figure 5 Shows a variant of the example of, Figure 3 wherein the stator winding is not formed by winding bars, but by windings formed in a plastic mixture. Detailed Description

[0057] Figure 1 An example of an electric machine 1 according to the invention is shown in cross-section. The dimensions of the electric machine 1 are determined such that it can be used in a motor vehicle, preferably in a road vehicle.

[0058] The electric machine 1 includes a rotor 3 and a stator 2 which are only schematically shown in. For the sake of clarity, the stator 2 is shown in a separate view in a cross-section perpendicular to the rotational axis D taken along the intersection line II-II in. According to, Figure 1 the rotor 3 has a rotor shaft 31 and may have a plurality of magnets not shown in detail in, Figure 2 wherein the magnetic polarization of the magnets changes along the circumferential direction U. The rotor 3 can rotate about the rotational axis D, the position of which is defined by the central longitudinal axis M of the rotor shaft 31. The axial direction A extending parallel to the rotational axis D is defined by the rotational axis D. The radial direction R is perpendicular to the axial direction A. The circumferential direction U rotates around the rotational axis D. Figure 1 in a cross-section perpendicular to the rotational axis D taken along the intersection line II-II in. According to, Figure 1 the rotor 3 has a rotor shaft 31 and may have a plurality of magnets not shown in detail in, Figure 1 which are magnetically polarized such that the magnetic polarization changes along the circumferential direction U. The rotor 3 can rotate about the rotational axis D, the position of which is defined by the central longitudinal axis M of the rotor shaft 31. The axial direction A extending parallel to the rotational axis D is defined by the rotational axis D. The radial direction R is perpendicular to the axial direction A. The circumferential direction U rotates around the rotational axis D.

[0059] As Figure 1As shown, the rotor 3 is arranged in the stator 2. Thus, the electric machine 1 shown here is a so-called internal rotor. However, a so-called external rotor can also be considered, in which the rotor 3 is arranged outside the stator 2. The rotor shaft 31 is mounted on the stator 2 so as to be able to rotate about the axis of rotation D in a first bearing 32a and in a second bearing 32b, the first bearing being axially spaced from the second bearing.

[0060] In addition to known ways, the stator 2 also includes a plurality of stator windings 6, which can be energized to generate a magnetic field. The electromagnetic interaction between the magnetic field generated by the magnets of the rotor 3 and the magnetic field generated by the conductive stator windings 6 causes the rotor 3 to rotate.

[0061] Figure 2 A cross-section in... shows that the stator 2 can have, for example, an annular stator body 7 made of iron. In particular, the stator body 7 can be formed by a plurality of stator body plates (not shown) that are stacked on top of each other along the axial direction A and bonded to each other. A plurality of stator teeth 8 are integrally formed inside the stator body 7 in the radial direction, the stator teeth extending in the axial direction A, protruding radially inward from the stator body 7 and being spaced apart from each other in the circumferential direction U. Each stator tooth 8 carries a stator winding 6. The individual stator windings 6 together form a winding arrangement. Depending on the number of magnetic poles to be formed by the stator windings 6, the individual stator windings 6 of the entire winding arrangement can be electrically connected to each other in a suitable manner.

[0062] When the electric machine 1 is in operation, the energized stator windings 6 generate waste heat, which must be dissipated from the electric machine 1 to prevent overheating of the electric machine and thus damage or even destruction of the electric machine 1. Therefore, the stator windings 6 are cooled by means of a coolant K, which passes through the stator 2 and absorbs the waste heat generated by the stator windings 6 by heat transfer.

[0063] To guide the coolant K through the stator 2, the electric machine 1 includes a coolant distribution chamber 4, into which the coolant K can be introduced through a coolant inlet 33. A coolant collection chamber 5 is arranged at a distance from the coolant distribution chamber 4 along the axial direction A. The coolant distribution chamber 4 is connected to the coolant collection chamber 5 through a plurality of cooling channels 10 (in Figure 1Only one of them can be seen) is in fluid communication with the coolant collection chamber 5. In a cross-section perpendicular to the axial direction A, the coolant distribution chamber 4 and the coolant collection chamber 5 can each have an annular geometry (not shown in the figure). A plurality of cooling channels 10 are arranged at a certain distance from each other along the circumferential direction U, and each cooling channel extends from the annular coolant distribution chamber 4 to the annular coolant collection chamber 5 along the axial direction A. The coolant K introduced into the coolant distribution chamber 4 via the coolant inlet 33 can thus be distributed to the corresponding cooling channels 10. After flowing through the cooling channels 10 and absorbing heat from the stator winding 6, the coolant K is collected in the coolant collection chamber 5 and discharged from the electric machine 1 again through the coolant outlet 34 arranged on the stator 2.

[0064] From Figure 1 and 2 As can be seen from the illustration, the stator winding 6 and the cooling channels 10 are arranged in the intermediate space 9 formed between two adjacent stator teeth 8 along the circumferential direction U. The intermediate space 9 is also known to those skilled in the art as the so-called "stator slot" or "stator groove", and they extend along the axial direction A like the stator teeth 8.

[0065] The following explains Figure 3 the illustration, which shows in detail the intermediate space 9 formed between two adjacent stator teeth 8 in the circumferential direction U, hereinafter also referred to as stator teeth 8a, 8b.

[0066] As Figure 3 shown, the intermediate space 9 has a radially inner opening 52, that is, it is designed as a radially inner opening. The intermediate space 9 can have a trapezoidal geometry, especially a rectangular geometry, in a cross-section perpendicular to the axial direction A. In Figure 3 the example, the cooling channels 10 are arranged in the region of the radially inner end 56a of the intermediate space 9 or the stator slot 54, that is, in the region of the opening 52.

[0067] To improve the heat transfer from the waste heat generated by the stator winding 6 to the coolant K flowing through the cooling channels 10, in addition to the cooling channels 10 and the stator winding 6, a thermally conductive plastic 11 is additionally arranged in the corresponding Figure 3 intermediate space 9. The plastic 11 is preferably introduced into the intermediate space 9 by injection molding.

[0068] As Figure 3 shown, the plastic 11 is arranged on the first surface portions 50b, 50c of two stator teeth 8 that are adjacent in the circumferential direction U and define the intermediate space 9. In addition, the plastic 11 is arranged on the second surface portion 50a of the stator body 7, which radially externally defines the intermediate space 9.

[0069] Advantageously, the plastic 11 disposed on the first surface portions 50b, 50c and the second surface portion 50a is an electrically insulating plastic. This ensures that both the cooling channels 10 disposed in the intermediate space 9 and the stator winding 6 disposed in the same intermediate space 9 are electrically insulated from the stator teeth 8 by the plastic 11. Additionally, the stator winding 6 is thermally conductively connected to the cooling channels 10 via the plastic 11, so that waste heat in or generated by the stator winding 6 is transferred via the plastic 11 to the coolant K flowing through the cooling channels 10 and can thus be dissipated from the stator winding 6.

[0070] The plastic 11 disposed on the first surface portions 50b, 50c and the second surface portion 50a forms an electrically insulating and thermally conductive insulating layer 51 that covers the first surface portions 50b, 50c and the second surface portion 50a. For example, the layer thickness d of the insulating layer 51 can be between 0.2 mm and 0.5 mm.

[0071] According to Figure 3 , the plastic 11 can not only form the insulating layer 51, but alternatively or additionally, can also form the phase insulator 58 disposed in the intermediate space 9 or the stator slots 54. The phase insulator 58 divides the intermediate space 9 into a radially inner sub-space 59a and a radially outer sub-space 59b. Thus, the first conductor element 60a forming the first phase winding 70a of the stator winding 6 can be disposed in the radially inner sub-space 59a. Similarly, the second conductor element 60b of the stator winding 6 can be disposed in the radially outer sub-space 59b, which forms a second phase winding 70b that is electrically insulated from the first phase winding 70a.

[0072] Advantageously, the phase insulator 58 extends in the circumferential direction U. The phase insulator 58 preferably connects two insulating layers 51 made of the plastic 11 to each other, and the two insulating layers are disposed on adjacent stator teeth 8a, 8b.

[0073] It can be seen that the plastic 11 not only forms the electrically insulating layer 51, but also forms a first protective coating 75 that is disposed in the intermediate space 9 and defines or surrounds the cooling channels 10. A tubular body or the like for fluid-tightly defining the cooling channels 10 is redundant because the coolant K cannot escape from the cooling channels.

[0074] In Figure 3 's exemplary case, the first protective coating 75 closes the opening 52 of the intermediate space 9 or the stator slots 54 that is formed open.

[0075] From Figure 3It can also be seen that the stator winding 6 is not only electrically insulated from the cooling channel 10 by the plastic 11 forming the first protective coating 75, but also thermally conductively connected to the cooling channel, so that the waste heat in or generated by the stator winding 6 can also be transferred through the first protective coating 75 to the coolant K flowing through the cooling channel 10.

[0076] The first conductor element 60a is arranged in the radially inner sub-space 59a, and the second conductor element 60b is arranged in the radially outer sub-space 59b.

[0077] The cooling channel 10 arranged in the region of the radially inner end 54a is arranged in the radially inner sub-space 59a, which is formed by the phase insulator 58 of the plastic 11.

[0078] As can be seen in Figure 3 the stator winding 6 arranged in the intermediate space 9 includes a first conductor element 60a and a second conductor element 60b, which are arranged in the intermediate space 9 adjacent to each other and spaced apart from each other by a certain distance along the radial direction R. A gap 61 is formed between two conductor elements 60a, 60b adjacent to each other along the radial direction R, and the gap can preferably extend along the circumferential direction U. Here, the plastic 11 forms a gap filler 62, and the gap 61 is completely filled with the gap filler.

[0079] In a similar manner, a gap 61 can be formed between the first and second conductor elements 60a, 60b and between the electrical insulations arranged on the first surface portions 50b, 50c of the stator teeth 8a, 8b. In this case, the plastic 11 also forms a gap filler 62, and the gap 61 is filled with the gap filler. It goes without saying that the gap 61 filled with the plastic 11 can also only extend locally or can exist in the form of so-called air inclusions. It is also conceivable that there are a plurality of gaps 61 or air inclusions, which are filled with the gap filler 62 made of the plastic 11. Therefore, as Figure 3 shown, in a cross-section perpendicular to the axial direction A, all the first and second conductor elements 60a, 60b are surrounded by the electrically insulating and thermally conductive plastic 11.

[0080] The first and second conductor elements 60a, 60b are respectively formed by a conductive and mechanically rigid material into the first or second winding bars 65a, 65b. In a cross-section perpendicular to the axial direction A, the first and second winding bars 65a, 65b respectively have a rectangular geometry 66 with two narrow sides 67 and two wide sides 68.

[0081] According to Figure 3, a first conductor element 60a is arranged in the radially inner sub-space 59a and electrically connected to each other for connection to a common first phase of a power supply. Correspondingly, a second conductor element 60b is arranged in the radially outer sub-space 59b and electrically connected to each other for connection to a common second phase of a power supply. In addition, the first conductor element 60a is electrically insulated from the second conductor element 60b by a phase insulator 58.

[0082] Figure 4 shows Figure 3 an improved version of the example. Figure 4 The example in Figure 3 differs from the example in

[0083] that in the region of the radially outer end 56b of the intermediate space 9 or in the region of the stator slot 54, additional cooling channels 10 are arranged, and the radially outer end is opposite to the radially inner end 56a with respect to the radial direction. Figure 4 In the example of Figure 4 , the plastic 11 forms a second protective coating 75 in a manner similar to the first protective coating 75 of the cooling channel 10. The second protective coating is arranged in the intermediate space 9, defines the additional cooling channels 10 and is thus surrounded by them. As can be seen from

[0084] Figure 5 shows Figure 3 a variant of the example of Figure 5 In the example of Figure 5 , the plastic forms a plastic composite, and the stator winding 6 is embedded in the plastic composite. In the example of

[0085] The plastic 11 disposed on the first surface portions 50b, 50c of the stator teeth 8a, 8b can preferably be formed of a first electrically insulating plastic material K1. The plastic 11 forming the phase insulator 58 can be formed of a second plastic material K2. The plastic 11 forming the first and second protective coatings 75 can be formed of the second plastic material K2 or of a third plastic material K3 different therefrom. The second plastic material K2 is expediently designed to be electrically insulating or electrically conductive. The third plastic material K3 can also be designed to be electrically insulating or electrically conductive. The first plastic material K1 can be a thermoplastic or a thermosetting plastic. The same applies to the second and third plastic materials K2, K3. In each case, two or even all three plastic materials K1, K2, K3 can have the same thermal conductivity. Alternatively, the first plastic material, and alternatively or additionally, the second plastic material, and alternatively or additionally, the third plastic material K1, K2, K3 can have different thermal conductivities. The first plastic material, and alternatively or additionally, the second plastic material, and alternatively or additionally, the third plastic material K1, K2, K3 can be the same material. Alternatively, the first plastic material, and alternatively or additionally, the second plastic material, and alternatively or additionally, the third plastic material K1, K2, K3 can be made of different materials.

[0086] Likewise, the thermal conductivity of the plastic 11, in particular of the first plastic material, and alternatively or additionally, of the second plastic material, and alternatively or additionally, of the third plastic material K1, K2, K3 is at least 0.5 W / mK, preferably at least 1 W / mK.

[0087] Referring again to the following Figure 1 。In addition, according to Figure 1 , the stator 2 having the stator body 7 and the stator teeth 8 is axially disposed between the first and second end plates 25a, 25b.

[0088] From Figure 1 it can be seen that a part of the coolant distribution chamber 4 is disposed in the first end plate 25a, while a part of the coolant collection chamber 5 is disposed in the second end plate 25b. Accordingly, the coolant distribution chamber 4 and the coolant collection chamber 5 are respectively partially formed by cavities 41a, 41b disposed in the plastic 11. The first cavity 41a is supplemented here by a cavity 42a formed in the first end plate 25a to form the coolant distribution chamber 4. Correspondingly, the second cavity 41b is supplemented by a cavity 42b formed in the second end plate 25b to form the coolant collection chamber 5. In the variant embodiment described above, the plastic 11 at least partially defines the coolant distribution chamber 4 and the coolant collection chamber 5.

[0089] The first end plate 25a may also include a coolant inlet 35 that fluidly connects the coolant distribution chamber 4 to a coolant inlet 33 arranged outside the first end plate 25a, in particular on the circumferential side as shown in Figure 1 . The second end plate 25b may correspondingly include a coolant outlet 36 that fluidly connects the coolant collection chamber 5 to a coolant outlet 34 arranged outside the end plate 25b, in particular on the circumferential side as shown in Figure 1 . This enables the coolant distribution chamber 4 and the coolant collection chamber 5 to be arranged radially outside the first and second ends 14a, 14b of the respective stator windings 6 and also to be arranged along the axial direction A as an extension of these ends 14a, 14b. By this measure, the ends 14a, 14b of the stator windings 6 that are particularly thermally loaded during the operation of the electric machine 1 are also cooled particularly effectively.

[0090] According to Figure 1 , the plastic 11 may also be arranged on the outer peripheral side 30 of the stator body 7 and thus form a plastic coating 11.1 on the outer peripheral side 30. Thus, the stator body 7 of the stator 2, which is usually formed by conductive stator plates, can be electrically insulated from the environment. Therefore, the arrangement of a separate housing for accommodating the stator body 7 can be dispensed with.

Claims

1. An electric machine (1), said electric machine - comprising a rotor (3) and a stator (2), wherein the rotor is rotatable about a rotation axis (D) defining an axial direction (A) of the electric machine (1), and the stator has a conductive stator winding (6); - comprising at least one cooling channel (10) through which a coolant (K) can flow to cool the stator winding (6), - Among them, The stator (2) has stator teeth (8) extending in the axial direction (A), the stator teeth being arranged at a distance from each other in the circumferential direction (U) of the rotor (3) and carrying the stator winding (6), - wherein at least one cooling channel (10) and at least one stator winding (6) are arranged in at least one intermediate space (9) formed in the circumferential direction (U) between two adjacent stator teeth (8, 8a, 8b), - wherein in the intermediate space (9) there is arranged a plastic (11) for transferring heat from the stator winding (6) to at least one cooling channel (10); the plastic (11) forms a protective coating in a cross-section perpendicular to the axial direction (A), which protective coating is arranged in the intermediate space (9) and completely defines or surrounds the cooling channel (10); wherein the plastic is arranged on all first surface portions (50b, 50c) of two adjacent stator teeth defining the intermediate space (9); wherein the electric machine further comprises a coolant distribution chamber (4) and a coolant collection chamber (5), the coolant distribution chamber (4) and the coolant collection chamber (5) being at least partially arranged in the plastic, the plastic being electrically insulating, the coolant distribution chamber (4) being formed by a first cavity (41a) in the plastic (11) and a cavity (42a) formed in a first end plate (25a), and the coolant collection chamber (5) being formed by a second cavity (41b) in the plastic (11) and a cavity (42b) formed in a second end plate (25b); the plastic at least partially defines the coolant distribution chamber (4) and the coolant collection chamber (5) to be thermally coupled to at least one stator winding (6); The coolant distribution chamber (4) and the coolant collection chamber (5) are respectively arranged radially outside the first end (14a) and the second end (14b) of the corresponding stator winding (6) and also extend along the axial direction (A) as an extension of the first end (14a) and the second end (14b).

2. The motor according to claim 1, characterized in that, The electric machine is for a motor vehicle.

3. The electric machine according to claim 1, characterized in that - the stator comprises a stator body (7), stator teeth (8a, 8b) projecting radially inwards from the stator body, and - the plastic is arranged on a second surface portion (50a) of the stator body, the second surface portion defining the intermediate space (9) radially externally.

4. The electric machine according to claim 3, characterized in that Plastic (11) disposed on the first surface portions (50b, 50c) and the second surface portion (50a) forms an electrical insulation layer (51) that covers the first surface portions of two adjacent stator teeth (8, 8a, 8b) defining an intermediate space (9) and / or the second surface portion of the stator body (7).

5. The electric machine according to one of claims 1 - 4, characterized in that at least one cooling channel (10) is arranged in the region of the radially inner end (56a) or the radially outer end (56b) of the intermediate space (9).

6. The electric machine according to claim 5, characterized in that the plastic (11) forms at least one phase insulation member (58) that is arranged in the intermediate space (9) and divides the intermediate space (9) into a radially inner sub - space and a radially outer sub - space (59a, 59b), such that a first conductor element (60a) of the stator winding (6) is arranged in the radially inner sub - space (59a), the first conductor element (60a) forming a first phase winding (70a), and a second conductor element (60b) of the stator winding (6) is arranged in the radially outer sub - space (59b), the second conductor element forming a second phase winding (70b) that is electrically insulated from the first phase winding (70a).

7. The electric machine according to claim 6, characterized in that the phase insulation member (58) extends in the circumferential direction (U) and connects two electrical insulation layers (51) to each other, the two electrical insulation layers (51) being arranged on adjacent stator teeth (8a, 8b) and made of plastic (11).

8. The electric machine according to claim 6, characterized in that - the stator winding includes at least one first conductor element (60a) and at least one second conductor element (60b), - the first conductor elements (60a) are arranged in the radially inner sub - space (59a) and are electrically connected to each other to be connected to a common first phase of a power supply, and - the second conductor elements (60b) are arranged in the radially outer sub - space (59b) and are electrically connected to each other to be connected to a common second phase of a power supply.

9. The electric machine according to claim 8, characterized in that in a cross - section perpendicular to the axial direction (A), at least one first and / or at least one second conductor element (60a, 60b) is surrounded by an electrically insulating and thermally conductive plastic.

10. The electric machine according to claim 6, characterized in that the first and / or second conductor elements (60a, 60b) are formed as winding bars (65a, 65b) made of a conductive material.

11. The electric machine according to claim 10, characterized in that in a cross - section perpendicular to the axial direction (A), at least one winding bar (65a, 65b) has a rectangular (66) geometry with two narrow sides (67) and two wide sides (68).

12. The electric machine according to claim 7, characterized in that The first conductor element (60a) is electrically insulated from the second conductor element (60b) by means of a phase insulator (58).

13. The electric machine according to one of claims 1 to 4, characterized in that Another cooling channel (10) is arranged in the region of the radially outer end (56b) or the radially inner end (56a) of the intermediate space (9).

14. The electric machine according to claim 8, characterized in that - The cooling channel (10) arranged in the region of the radially inner end (56a) is arranged in a radially inner sub-space (59a) formed by a phase insulator (58) of plastic (11); or / and - The cooling channel (10) arranged in the region of the radially outer end (56b) is arranged in a radially outer sub-space (59b) formed by a phase insulator (58) of plastic (11).

15. The electric machine according to claim 8, characterized in that - A gap (61) is at least partially formed between at least two conductor elements (60a, 60b) and / or between at least one conductor element (60a, 60b) and an electrical insulation layer (51), the electrical insulation layer being arranged on a first surface portion (50b, 50c) of the stator teeth (8, 8a, 8b) and / or on a second surface portion (50a) of the stator body (7); and - The plastic (11) forms a gap filler (62), and the gap (61) is at least partially filled with the gap filler (62).

16. The electric machine according to one of claims 1 to 4, characterized in that The plastic (11) comprises a plastic composite, and the stator winding (6) is embedded in the plastic composite.

17. The electric machine according to one of claims 1 to 4, characterized in that The intermediate space (9) has a trapezoidal geometry in a cross-section perpendicular to the axial direction (A).

18. The electric machine according to claim 6, characterized in that - The plastic (11) arranged on the first surface portion (50b, 50c) of the stator teeth (8, 8a, 8b) is formed of a first electrically insulating plastic material (K1), - The plastic (11) forming at least one phase insulator (58) is formed of a second plastic material (K2), - The plastic (11) forming the protective coating (75) and / or another protective coating (75) is formed of the second plastic material (K2) or of a third plastic material (K3).

19. The electric machine according to claim 18, characterized in that The second plastic material (K2) is designed to be electrically insulating or conductive; or / and The third plastic material (K3) is designed to be electrically insulating or conductive.

20. The electric machine according to claim 18, characterized in that - The first plastic material (K1) and / or the second plastic material (K2) and / or the third plastic material (K3) is a thermoplastic, - The first plastic material (K1) and / or the second plastic material (K2) and / or the third plastic material (K3) is a thermosetting plastic.

21. The electric machine according to claim 18, characterized in that - The first and / or second and / or third plastic materials (K1, K2, K3) have the same thermal conductivity; or / and - The first and / or second and / or third plastic materials (K1, K2, K3) have different thermal conductivities.

22. The electric machine according to claim 18, characterized in that - The first and / or second and / or third plastic materials (K1, K2, K3) are the same material; or / and - The first and / or second and / or third plastic materials (K1, K2, K3) are different materials.

23. The motor according to any one of claims 1-4, characterized in that, The stator winding (6) is part of a distributed winding.

24. The motor according to claim 18, wherein The thermal conductivity of the plastic (11) is at least 0.5 W / mK.

25. The electric machine according to any one of claims 1 - 4, characterized in that The intermediate space (9) is formed by means of the plastic (11) such that there are substantially no gaps and / or no air inclusions.

26. The electric machine according to claim 8, characterized in that In a cross - section perpendicular to the axial direction (A), all first or / and second conductor elements (60a, 60b) are surrounded by an electrically insulating and thermally conductive plastic.

27. The electric machine according to claim 10, characterized in that In a cross - section perpendicular to the axial direction (A), all winding bars (65a, 65b) have a geometry of a rectangle (66) with two narrow sides (67) and two wide sides (68).

28. The motor according to claim 15, characterized in that, The gap (61) is completely filled with a gap filler (62).

29. The electric machine according to any one of claims 1 - 4, characterized in that The intermediate space (9) has a rectangular geometry in a cross - section perpendicular to the axial direction (A).

30. The motor according to claim 18, characterized in that, The thermal conductivity of the plastic (11) is at least 1 W / mK.

31. The electric machine according to claim 18, characterized in that The thermal conductivity of the first and / or second and / or third plastic materials (K1, K2, K3) is at least 0.5 W / mK.

32. The electric machine according to claim 18, wherein, The thermal conductivity of the first and / or second and / or third plastic materials (K1, K2, K3) is at least 1 W / mK.

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