Insulators for motors

Abstract

The invention relates to an electric machine comprising an insulator (100). The insulator (100) comprises an outer wall (101a, 101b, 101c, 101d) made of plastic (K), the outer wall defining a body inner space (104). At least one winding area (106a, 106b) for accommodating a stator winding (6) and at least one channel area (107a, 107b) for accommodating a cooling channel (10) are arranged in the body inner space (104).

Description

Technical Field

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

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

[0003] A machine of a general type is known, for example, from US 5,214,325. It comprises a housing which encloses an interior space and has a shell which extends circumferentially in the circumferential direction of the housing and delimits the interior space radially, a rear side wall axially delimiting the interior space axially at one side, and a front side wall axially delimiting the interior space axially at the other side. The stator of the motor is fixedly connected to the housing. The rotor of the motor is arranged in the stator, wherein the rotor shaft of the rotor is rotatably mounted on the front side wall via a front bearing.

[0004] The stator of a conventional electric machine usually comprises a stator winding which is electrically excited during operation of the electric machine. This results in an increase in heat which has to be dissipated in order to avoid overheating and associated damage or even destruction of the stator. For this reason, it is known from conventional electric machines to equip the electric machine with a cooling device for cooling the stator, in particular the stator winding. Such a cooling device comprises one or more cooling channels through which a coolant flows and which are arranged in the vicinity of the stator winding in the stator, usually in a gap forming a stator slot between two stator teeth which are adjacent in the circumferential direction of the stator and which also accommodate the stator winding. The heat transfer from the stator winding to the coolant enables the heat to be dissipated from the stator.

[0005] In this case, it has proven disadvantageous that an effective heat transfer from the stator to the coolant flowing through the corresponding cooling channels can only be achieved with a relatively complex structure. However, this has a negative impact on the production costs of the electric machine.

[0006] Furthermore, it has proven to be problematic in the case of conventional electric machines that, under certain circumstances, if the winding insulation of the stator winding is damaged—for example as a result of manufacturing or during assembly—and after the stator winding has been introduced into the gap, the stator winding—for example as a result of assembly—comes into contact with the cooling channel or the coolant or the stator teeth, then undesirable electrical short circuits may occur between the stator winding and the coolant passing through the cooling channel and between the stator winding and the stator teeth of the stator. Summary of the invention

[0007] It is therefore an object of the present invention to provide an improved embodiment of an electric machine, in which this disadvantage is largely or even completely eliminated. In particular, the present invention provides an improved embodiment of an electric machine, characterized by an improved cooling of the stator windings of the stator.

[0008] The basic idea of ​​the invention is therefore to provide an electrical insulator which can be inserted as a prefabricated structural unit into the gap between two stator teeth of the stator of an electric machine, the so-called stator slot. After the insulator has been inserted into the gap or in the stator slot, the stator winding can be introduced into the gap. In this case, the insulator present there firstly facilitates the positioning of the stator winding in the corresponding gap and secondly can ensure the required electrical insulation of the stator winding with respect to the cooling channel or the coolant passing through the cooling channel during the operation of the electric machine, that is to say in particular serves as a heat transfer medium. This finally means that the waste heat generated by the stator winding can be transferred to the cooling channel via the plastic, which is present in the gap and through which the coolant flows during the operation of the electric machine. This effect can be improved by selecting a suitable plastic with high thermal conductivity. Since plastics generally have electrical insulation properties, it is also possible that the stator winding arranged in the insulator is electrically insulated from the stator teeth. In this way, undesired electrical short circuits between the conductor elements of the stator winding can be prevented, even in the event of damage to the winding insulation.

[0009] The electrical insulator for an electric machine according to the invention comprises an outer wall made of plastic, which partially delimits the inner space of the body. Preferably, the plastic is embodied in an electrically insulating manner. In addition, the plastic can also be used for heat transfer. In the inner space of the body there is at least one winding area for accommodating a stator winding and at least one channel area for accommodating a cooling channel.

[0010] In a preferred embodiment, the insulator has at least one partition wall made of plastic, preferably electrically insulating plastic, which divides the interior space of the body into at least one winding region and at least one channel region. If, after the insulator has been installed in the stator slots, during assembly of the stator, the stator winding is arranged in the winding region and the cooling channel is arranged in the channel region of the insulator, undesired electrical short circuits between the stator winding and the cooling channel with the coolant can be prevented in this way, even in the event of damage to the winding insulation.

[0011] In a preferred embodiment, the outer wall and the at least one partition wall extend in the axial direction. In this embodiment, in a cross section perpendicular to the axial direction, at least one winding zone and the channel zone are arranged adjacent to each other. This makes it possible to arrange the stator winding and the cooling channel for cooling the stator winding directly adjacent to each other. In this way, a particularly effective heat transfer from the stator winding to the cooling channel can be achieved. At the same time, the desired electrical insulation between the stator winding and the cooling channel is ensured by the partition wall.

[0012] In a preferred development, two channel areas for accommodating the first and second cooling channels are provided inside the body. In this development, in a cross section perpendicular to the axial direction, at least one winding area is arranged between the two channel areas and is separated from the two channel areas by two partition walls. This geometric arrangement of the stator winding relative to the two cooling channels makes it possible to transfer waste heat from the stator winding to the two cooling channels on both sides. In this way, particularly intensive cooling of the stator winding can be achieved.

[0013] In a further advantageous refinement, two winding zones are provided instead of just one, which are arranged adjacent to one another in a cross section perpendicular to the axial direction. In this advantageous refinement, the winding zones are separated from one another by means of an interphase insulation consisting of plastic. In this way, undesired electrical short circuits between conductor elements arranged in two different winding zones are prevented. This applies in particular if an electrically insulating plastic is chosen as the material for the partition wall. This allows the conductor elements to be arranged in two winding zones which can be connected to different electrical phases of the power supply in a manner electrically isolated from one another. This may be necessary, for example, if the motor is intended to be operated as a two-phase motor.

[0014] Advantageously, the phase insulator can be formed by a further partition wall of the insulator. Particularly preferably, the partition wall material is formed uniformly or even integrally on the outer wall of the insulator. This variant has particularly low production costs.

[0015] Advantageously, the insulator can be an injection-molded part. Such an injection-molded part can be produced in a technically simple manner and can therefore be produced particularly cost-effectively, in particular in large quantities. Alternatively or additionally, the insulator can be a monolithic body. This also has a favorable effect on the production costs. Alternatively or in addition, the insulator can be an extruded body.

[0016] Advantageously, the insulator can have a parallelepiped geometry. In a cross section perpendicular to the axial direction, the insulator can also advantageously have a trapezoidal geometry, preferably a rectangular geometry. This means that the insulator has a geometry that generally corresponds to the geometry of the stator slots into which the insulator is inserted during assembly of the stator of the electric machine. In a variant, other geometries are also conceivable, wherein in the case of such alternative geometries it also applies that such alternative geometries particularly preferably substantially correspond to the geometry of the relevant stator slots into which the insulator is inserted.

[0017] According to another advantageous improvement, an axial stop can be formed on at least one outer wall of the insulator at an axial end relative to the axial direction. Such an axial stop facilitates the insertion of the insulator into the corresponding gap in the axial direction. In particular, the correct axial positioning of the insulator in the gap is ensured.

[0018] According to a further development, which is particularly preferred because it is technically simple to implement, the axial stop can be formed as an outwardly protruding wall collar which is formed, preferably integrally formed, on at least one outer wall of the insulating body. This embodiment has particularly low manufacturing costs.

[0019] In an advantageous development, a spacer structure is provided on at least two outer walls, by means of which the outer walls can be inserted at a defined distance into the stator slots of the stator of the electric machine. In this way, the insertion of the insulator into the corresponding gap forming the stator slots is facilitated. In particular, the insulator can thus be positioned particularly accurately in the gap. The gap between the outer wall and the stator teeth and / or the stator body, which gap may result from the arrangement of the insulator at a distance from the two stator teeth and / or the stator body, can be filled with a heat transfer layer made of plastic, which facilitates the heat transfer to the coolant flowing through the cooling channel.

[0020] Particularly preferably, the spacer structure is formed by a projection which is arranged on the outer side of the respective outer wall facing away from the interior of the main body.

[0021] This embodiment is particularly easy to implement technically and has cost advantages during production.

[0022] According to an advantageous development, the projection can be formed integrally on the outer wall. This embodiment has also proven to be particularly cost-effective.

[0023] In another advantageous development, the insulator is formed such that it can be inserted into the stator slots in the axial direction. As a result, the insulator can be installed particularly easily in the stator slots, thereby making it possible to manufacture an electric machine having such an insulator particularly cost-effectively.

[0024] Advantageously, the insulator is formed in such a way that it can be inserted into the stator slot with an exact fit. It has proven particularly advantageous here if the insulator is formed in such a way that it can be inserted into the stator slot with an interference fit or transition fit. An insulator formed in this way advantageously does not require any additional measures for fixing the insulator in the stator slot.

[0025] According to another preferred development of the insulator, the insulator is formed in a dimensionally rigid manner. Particularly preferably, in this case, the insulator is formed from a dimensionally rigid material. This offers the advantage that if the insulator is inserted into the stator slot in an interference fit, the insulator can absorb the installation forces without damage.

[0026] In another advantageous development, the insulator is reinforced by means of a partition wall. This means that, in addition to dividing the interior of the body, the partition wall also performs the task of mechanically reinforcing the insulator. As a result, the installation forces that the insulator can absorb during its installation without damage can be advantageously further increased.

[0027] In another preferred embodiment of the insulator, the insulator is produced in a non-forming manner. Such an insulator is produced in particular without bending and / or expansion of the semi-finished product. Thus, advantageously, internal stresses in the insulator which are usually generated during the forming process can be effectively avoided or at least reduced to a reduced level.

[0028] According to another preferred development, a cross section defined perpendicularly to the axial direction within the body of the insulator is constant over the extension of the insulator in the axial direction. Advantageously, such an insulator can be manufactured in large quantities, particularly cost-effectively, by an extrusion process.

[0029] In another advantageous development of the insulator, a cross section of the insulator defined perpendicular to the axial direction is both axially symmetrical and point-symmetrical within the insulator. Such an embodiment of the insulator advantageously allows a particularly uniform distribution of components that can be positioned within the body, such as cooling channels and / or stator windings of an electric machine with such an insulator. Such a uniform distribution is desirable because the stator windings that can be accommodated within the body can thus be cooled particularly uniformly by means of the cooling channels.

[0030] Advantageously, the outer walls of the insulator are connected to one another. Particularly advantageously, the outer walls of the insulator are connected to one another without seams and / or joints. This has a favorable effect on the mechanical properties of the insulator.

[0031] The present invention also relates to an electric machine, in particular an electric machine for a vehicle. The electric machine comprises a rotor and a stator, the rotor being rotatable about a rotation axis defining the axial direction of the electric machine, the stator having an electrically conductive stator winding. In addition, the electric machine comprises at least one cooling channel through which a coolant can flow for cooling the stator winding. In this case, the stator has stator teeth extending in the axial direction and arranged at a distance from each other in the circumferential direction of the rotor, the stator teeth protruding from a stator body of the stator, preferably radially inwardly, and carrying the stator winding. A gap is formed between two stator teeth adjacent in the circumferential direction, respectively.

[0032] According to the invention, an insulator as described above is arranged or accommodated in at least one gap. Therefore, the aforementioned advantages of the insulator also apply to the electric machine according to the invention. Preferably, such an insulator is arranged in a plurality of gaps of the stator, particularly preferably in all gaps. According to the invention, in this case, the stator winding is arranged in at least one winding zone of the insulator. Likewise, a cooling channel for the flow of a coolant is arranged in at least one channel zone of the insulator.

[0033] In a preferred embodiment, the insulator is inserted into the gap. Such insertion of the insulator into the gap simplifies the installation of the prefabricated insulator in the respective gap and thus simplifies the assembly of the stator of the electric machine.

[0034] Advantageously, the axial direction of the insulator extends parallel to the axial direction of the electric machine.

[0035] It is particularly advantageous if the insulator arranged in the gap extends along the entire gap length, which is measured in the axial direction of the electric machine.

[0036] Particularly preferably, the insulator comprises two channel regions, which are arranged in a cross section perpendicular to the axial direction in the radially inner end and the radially outer end of the gap. In this variant, the first cooling channel is arranged in the first channel region and the second cooling channel is arranged in the second channel region. In this way, sufficient structural space is provided in the region between the two channel regions or ends for accommodating stator windings with a large number of conductor elements. At the same time, effective cooling of these stator windings is simultaneously ensured by the two cooling channels.

[0037] Advantageously, a first channel region with first cooling channels can be arranged in a radially inner end of the gap, and a second channel region with second cooling channels can be arranged in a radially outer end of the gap. The stator winding is arranged between the two cooling channels with respect to the radial direction, as a result of which an efficient heat transfer from the stator winding to the coolant through the two cooling channels is possible.

[0038] Preferably, at least one winding zone is arranged between two channel zones in the radial direction of the stator. Particularly preferably, two winding zones, namely the first and the second winding zone, are arranged in the radial direction, preferably directly one after the other, between the two channel zones. Thus, in this variant, the first channel zone, the first winding zone, the second winding zone and the second channel zone are arranged one after the other in the radial direction from the radial inside to the radial outside.

[0039] In a further advantageous development, the insulator comprises two winding zones which are arranged adjacent to one another in a cross section perpendicular to the axial direction. In this development, the two winding zones are separated from one another by means of an interphase insulation consisting of plastic. This allows the conductor elements of the stator winding which are arranged in the gap to be arranged in two winding zones which are intended to be connected to different electrical phases of the power supply. This may be necessary if the electrical machine is intended to be operated as a two-phase machine.

[0040] According to another preferred embodiment, the stator winding is part of a distributed winding.In this embodiment, the insulator is formed such that it opens radially inwards, that is to say towards the opening of the gap or stator slot.

[0041] According to an advantageous refinement, the winding comprises a first conductor element and a second conductor element. In this refinement, the first conductor elements are arranged in a first winding zone and are electrically connected to each other in order to be connected to a common first phase of the power supply. Similarly, in this refinement, the second conductor elements are arranged in a second winding zone and are electrically connected to each other in order to be connected to a common second phase of the power supply. This enables the motor to be operated as a two-phase motor with high operational reliability.

[0042] Particularly preferably, in a cross section perpendicular to the axial direction, at least one first conductor element and / or a second conductor element of the stator winding arranged in the gap is surrounded by plastic. Particularly preferably, this is true for all first conductor elements and / or second conductor elements of the stator winding. In this way, it is ensured that no undesired electrical short circuit of the stator winding and the coolant flowing through the cooling channel occurs.

[0043] Advantageously, the first conductor element and / or the second conductor element can be formed as a winding bar consisting of an electrically conductive material. Particularly preferably, these conductor elements are formed in a mechanically rigid manner, such an embodiment of the conductor element as a winding bar, in particular consisting of a mechanically rigid material, facilitates the introduction of the conductor element into an insulator arranged in a gap of the stator for assembly of the electric machine.

[0044] According to a further preferred embodiment, in a section perpendicular to the axial direction at least one winding bar, preferably all winding bars, have a rectangular geometry with two narrow sides and two broad sides, which has proven to be particularly space-saving.

[0045] Particularly preferably, the first conductor element is electrically insulated from the second conductor element by means of an interphase insulation. In this way, an undesired electrical short circuit between two conductor elements which are connected or intended to be connected to different electrical phases of a power supply can be avoided.

[0046] According to another advantageous refinement, a first heat transfer layer made of plastic is arranged between the stator winding and the insulation. In this way, the heat dissipation of the stator winding can be improved. In particular, the formation of undesired air gaps or air inclusions that would reduce the heat dissipation from the stator winding can be avoided.

[0047] Furthermore, the first heat transfer layer can be arranged between at least two adjacent conductor elements. In this way, an undesired electrical short circuit between two adjacent conductor elements can be prevented.

[0048] According to another preferred embodiment, a second heat transfer layer consisting of plastic is arranged between the cooling channel and the thermal insulation. Thus, the heat transfer to the cooling channel or the coolant flowing through the cooling channel can be improved. In particular, the formation of undesirable air gaps or air inclusions that would reduce the heat transfer to the cooling channel can be avoided.

[0049] As an alternative or in addition to the first and / or second heat transfer layer, a third heat transfer layer consisting of plastic can be arranged between the insulation and the stator body with two adjacent stator teeth. In this way, the dissipation of heat transfer from the stator teeth or from the stator body can be improved. In particular, the formation of undesired air gaps or air inclusions that would reduce the heat transfer from the stator teeth or from the stator body can be avoided.

[0050] Advantageously, the first conductor elements can be arranged in a radially inner winding zone and can be electrically connected to one another for connection to a common first phase of the power supply. In this variant, the second conductor elements are arranged in a radially outer winding zone and are electrically connected to one another for connection to a common second phase of the power supply. This variant enables the electric machine to be implemented or operated as a two-phase electric machine, requiring only a small amount of construction space. In particular, in this way, a particularly large number of conductor elements of the stator winding can be arranged in the corresponding gaps, which improves the performance of the electric machine.

[0051] According to another preferred embodiment, in a cross section perpendicular to the axial direction, at least one first or / and second conductor element, preferably all first or / and second conductor elements, are surrounded by plastic. In this way, the electrical insulation of the conductor elements, in particular with respect to the electrical insulation of the cooling channel, is improved in a redundant manner.

[0052] Advantageously, the spacer structure of the insulator can be supported on the stator teeth and, alternatively or additionally, on the stator body. In this way, the insulator is fixed in a mechanically stable manner in the gap.

[0053] In another advantageous development, a support structure can be provided on those surface sections of the two stator teeth or / and the stator body that face the gap, on which the outer wall of the insulator is supported, so that the outer wall is arranged at a certain distance from the stator teeth or / and the stator body, respectively. In this way, it is facilitated to insert the insulator into the corresponding gap forming the stator slot. In particular, in this way, the insulator can be positioned particularly accurately in the gap. Then, the air gap or air inclusion between the outer wall and the stator teeth and / or the stator body, which air gap or air inclusion may be generated by the arrangement of the insulator at a certain distance from the two stator teeth and / or the stator body, can be filled with a heat transfer layer composed of plastic. This leads to an improved transfer of the heat generated at the stator winding and the stator body during operation of the electric machine to the coolant flowing through the cooling channel.

[0054] Advantageously, the support structure is formed by projections from the stator teeth or / and from the stator body, respectively, into the gap.This embodiment is particularly easy to implement technically and therefore has cost advantages during production.

[0055] According to an advantageous development, the projections are formed integrally on the stator teeth and / or on the stator body, respectively. This embodiment has proven to be particularly cost-effective.

[0056] In a further preferred embodiment, an additional cooling channel is formed in the stator body, in particular in the region of the stator body between two stator teeth which delimit the gap. Such an additional cooling channel can be realized, for example, in the form of a perforation or in the form of a hole in the corresponding stator body. Particularly preferably, the additional cooling channel is arranged in a region of the stator body which delimits the gap radially on the outside and adjoins the gap radially inwardly from the gap. In this way, an additional cooling effect can be produced in the gap, which is associated with an improved heat dissipation from the stator winding arranged in the gap.

[0057] In another preferred embodiment, the plastic of the first heat transfer layer is formed by a first plastic material, preferably an electrically insulating first plastic material. Alternatively or additionally, in this embodiment, the plastic of the second heat transfer layer can be formed by a second plastic material, preferably an electrically insulating second plastic material. Alternatively or additionally, in this embodiment, the plastic of the third heat transfer layer can be formed by a third plastic material, preferably an electrically insulating third plastic material. Alternatively or additionally, in this embodiment, the plastic of the insulator, in particular the plastic of the outer wall of the insulator, can be formed by a fourth plastic material, preferably an electrically insulating fourth plastic material.

[0058] Advantageously, the first plastic material or / and the second plastic material or / and the third plastic material or / and the fourth plastic material can be thermoplastics. Alternatively or additionally, the first plastic material or / and the second plastic material or / and the third plastic material or / and the fourth plastic material can be thermosetting plastics. In this case, the thermal conductivity of the thermosetting plastic and the thermoplastic can be set by selecting the material composition. Therefore, the thermal conductivity of the thermoplastic can be greater than or equal to the thermal conductivity of the thermosetting plastic, and vice versa. The use of thermoplastics has various advantages over the use of thermosetting plastics. As an example, due to the reversible forming method adopted during its processing, thermoplastics show better recyclability or have lower brittleness and improved damping properties compared to thermosetting plastics. However, since the procurement of thermoplastics is generally more expensive than thermosetting plastics, it is recommended to selectively use thermoplastics for cost reasons. The use of thermosetting plastics with reduced thermal conductivity in those areas where heat transfer is less critical is associated with reducing the manufacturing cost of the motor.

[0059] Advantageously, the first plastic material and / or the second plastic material and / or the third plastic material and / or the fourth plastic material have the same thermal conductivity. Alternatively or additionally, the first plastic material and / or the second plastic material and / or the third plastic material and / or the fourth plastic material can have different thermal conductivities.

[0060] Advantageously, the first plastic material and / or the second plastic material and / or the third plastic material and / or the fourth plastic material can be the same material. Likewise, the first plastic material and / or the second plastic material and / or the third plastic material and / or the fourth plastic material can also be different materials.

[0061] Advantageously, the thermal conductivity of the plastic, in particular the thermal conductivity of the first plastic material and / or the second plastic material and / or the third plastic material and / or the fourth plastic material is at least 0.5 W / mK, preferably at least 1 W / mK.

[0062] According to a particularly preferred embodiment, the stator winding is part of a distributed winding.

[0063] The invention also relates to a motor vehicle comprising an electric machine as described above. Therefore, the advantages described above for the electric machine also apply to the motor vehicle according to the invention.

[0064] It goes without saying that the features mentioned above and the features still to be explained below can be used not only in the respectively indicated combination but also in other combinations or alone, without departing from the scope of the present invention.

[0065] Preferred exemplary embodiments of the invention are shown in the drawings and are explained in more detail in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] In the accompanying drawings, schematically:

[0067] Figure 1 An example of an insulator according to the invention is shown in an isometric view,

[0068] Figure 2 The cross-sectional view shows Figure 1 The insulator,

[0069] Figure 3 It is shown that the invention includes Figure 1 and Figure 2 An example of an insulator for a motor,

[0070] Figure 4 The cross section perpendicular to the axis of rotation of the rotor shows the Figure 3 The stator of the motor,

[0071] Figure 5 Shows Figure 4 A detailed illustration of the gap area between two adjacent stator teeth in the circumferential direction of the stator,

[0072] Figure 6 , Figure 7 Shows Figure 5 A variation of the example. DETAILED DESCRIPTION

[0073] Figure 1 and Figure 2 An example of an insulator 100 for a stator of an electric machine according to the invention is shown, the insulator being composed of plastic 11. Advantageously, the insulator 100 is an injection-molded component. Furthermore, the insulator 100 can be a monolithic body and, alternatively or additionally, can be an extruded body.

[0074] Figure 1 The insulator 100 is shown in an isometric view, and Figure 2 The insulator is shown in cross-sectional view. The insulator 100 defines a main interior 104. Figure 1 The insulator 100 has a parallelepiped geometry. The parallelepiped is formed by four outer walls 101a, 101b, 101d made of plastic 11. The four outer walls 101a-d extend along the axial direction a. Figure 2 In the cross section shown perpendicular to the axial direction a, the outer wall 101a-d forms two narrow sides 102a, 102b and two wide sides 103a, 103b. The two narrow sides 102a, 102b are opposite to each other. Similarly, the two wide sides 103a, 103b are opposite to each other. The two narrow sides 102a, 102b are preferably arranged orthogonally to the two wide sides 103a, 103b.

[0075] like Figure 1 and Figure 2 As shown, the body interior 104 is divided into the first and second winding areas 106a, 106b and the first and second channel areas 107a, 107b by partition walls 105a, 105b, 105c made of plastic 11, and the partition walls also extend in the axial direction a. Therefore, the first partition wall 105a is arranged between the first winding area 106a and the first channel area 107a. The second partition wall 105b is arranged between the second winding area 106b and the second channel area 107b.

[0076] The third partition wall 105c is arranged between the first winding area 106a and the second winding area 106b. Figure 2 In the cross section shown, the three partition walls 105a, 105b, 105c extend parallel to each other and also parallel to the two outer walls 101c, 101d. Therefore, the three partition walls 105a, 105b, 105c extend perpendicularly to the two outer walls 101a, 101b.

[0077] The two channel areas 107a and 107b are used to accommodate the first cooling channel and the second cooling channel ( Figure 1 and Figure 2 Similarly, the two winding areas 106a, 106b are used to accommodate the conductor elements of the stator winding ( Figure 1 and Figure 2 not shown).

[0078] like Figure 1 and Figure 2 As shown, the two winding zones 106a, 106b are arranged adjacent to each other and one after the other. The two winding zones 106a, 106b are additionally arranged between two channel zones 107a, 107b. In addition, the two winding zones 106a, 106b are electrically insulated and spatially separated from each other by an interphase insulation 108 made of plastic 11, which is formed by the existing partition wall 105c.

[0079] according to Figure 1 , axial stoppers 109 can be formed at axial ends 111 of the four outer walls 101 a - 101 d of the insulator 100 .

[0080] The axial stop 109 can be formed as an outwardly protruding, partially or completely circumferential wall collar 110 which is integrally formed on all four outer walls 101 a - d of the insulating body 100 .

[0081] Refer to the following Figure 3 and Figure 4An electric machine 1 is presented comprising the above described insulator 100. The electric machine 1 is dimensioned such that it can be used in a vehicle, preferably a road vehicle. Figure 3 The electric machine 1 is shown in longitudinal section, and Figure 4 The electric machine is shown in cross section.

[0082] The motor 1 includes a rotor 3 and a stator 2. Figure 3 For illustration, Figure 4 In a separate view along Figure 3 The stator 2 is shown in a section perpendicular to the rotation axis D along the section line II-II. Figure 3 The rotor 3 has a rotor shaft 31 and can have a plurality of magnets. Figure 3 The magnets are not shown in more detail in the drawing, the magnetic polarization of which alternates in a circumferential direction U. The rotor 3 is rotatable about an axis of rotation D, the position of which is defined by a central longitudinal axis M of the rotor shaft 31. The axis of rotation D defines an axial direction A extending parallel to the axis of rotation D. The radial direction R is perpendicular to the axial direction A. The circumferential direction U rotates around the axis of rotation D.

[0083] As from Figure 3 As can be seen in the figure, the rotor 3 is arranged in the stator 2. The electric machine 1 shown here is therefore a so-called inner rotor. However, a so-called outer rotor embodiment is also conceivable, in which the rotor 3 is arranged outside the stator 2. The rotor shaft 31 is mounted in a first bearing 32a and, axially at a distance therefrom, in a second bearing 32b, which can rotate about an axis of rotation D on the stator 2.

[0084] It is also known that the stator 2 comprises a plurality of stator windings 6 which can be electrically excited to generate a magnetic field. The magnetic 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.

[0085] Figure 2 The cross section in shows that the stator 2 can have an annular stator body 7, for example an annular stator body made of iron. In particular, the stator body 7 can be formed by a plurality of stator body plates (not shown), which are stacked on top of each other in the axial direction A and are adhesively engaged with each other. A plurality of stator teeth 8 are integrally formed radially inward on the stator body 7, which extend in the axial direction A, protrude radially inward away from the stator body 7, and are arranged at a certain distance 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 formed by the stator winding 6, the individual stator windings 6 of the entire winding arrangement can be electrically connected together accordingly.

[0086] During operation of the electric machine 1, the electrically excited stator winding 6 generates waste heat which must be dissipated from the electric machine 1 in order to prevent overheating and associated damage or even destruction of the electric machine 1. Therefore, the stator winding 6 is cooled by means of a coolant K which passes through the stator 2 and absorbs the waste heat generated by the stator winding 6 by heat transfer.

[0087] In order to allow the coolant K to pass through the stator 2, the electric machine 1 comprises a coolant distribution chamber 4, into which the coolant K can be introduced via a coolant inlet 33. The coolant collecting chamber 5 is arranged at a distance from the coolant distribution chamber 4 in the axial direction A. The coolant distribution chamber 4 is in fluid communication with the coolant collecting chamber 5 via a plurality of cooling channels 10. Figure 3 Only one of them can be seen in the illustration. In a cross section perpendicular to the axial direction A, which is not shown in the figure, the coolant distribution chamber 4 and the coolant collecting chamber 5 can each have an annular geometry. Along the circumferential direction U, a plurality of cooling channels 10 are arranged at a certain distance from each other, and these cooling channels extend from the annular coolant distribution chamber 4 to the annular coolant collecting chamber 5 along the axial direction A. Therefore, the coolant K introduced into the coolant distribution chamber 4 through the coolant inlet 33 can be distributed to each cooling channel 10. After flowing through the cooling channels 10 and absorbing heat from the stator winding 6, the coolant K is collected in the coolant collecting chamber 5 and is led out of the motor 1 again via the coolant outlet 34 provided on the stator 2.

[0088] like Figure 3 and Figure 4 As shown, a gap 9 is formed between two adjacent stator teeth 8 in the circumferential direction U. The gaps 9 are also referred to as so-called "stator slots" or "stator slits" by those skilled in the relevant art, and they extend in the axial direction A like the stator teeth 8. An insulator 100 made of plastic 11 for accommodating the stator winding 6 and the cooling channel 10 is inserted into each gap 9. In this case, the insulator 100 is arranged in the corresponding gap 9 in such a way that the axial direction A of the insulator 100 extends parallel to the axial direction A of the motor 1 or the stator 2.

[0089] Advantageously, the insulator 100 arranged in the respective gap 9 extends along the entire gap length I, which is measured along the axial direction A of the electric machine 1 (in this respect, see also Figure 3 ).

[0090] Below Figure 5 , which shows a detailed view of a gap 9 formed between two stator teeth 8 adjacent to each other in the circumferential direction U, which are also referred to as stator teeth 8a, 8b in the following. Figure 5 The gap 9 is shown in a section perpendicular to the axial direction A.

[0091] according to Figure 5 , the gap 9 has an opening 52 radially on the inside, that is, the opening is formed so that it is radially open on the inside. The gap 9 can have a trapezoidal geometry, in particular a rectangular geometry, in a cross section perpendicular to the axial direction A. The same applies to the geometry of the insulating body 100 in said cross section. Particularly advantageously, the gap 9 and the insulating body 100 have the same geometry or outer contour. Figure 5 In the example of , the first cooling channel 10 is arranged in the region of the radially inner end 56a of the gap 9 or stator slot 54, that is, in the region of the opening 52. In the region of the radially outer end 56b of the gap 9, that is, in the vicinity of the stator body 7 which delimits the gap 9 on the radial outer side, another second cooling channel 10 is provided.

[0092] like Figure 5 As shown, the stator winding 6 arranged in the gap 9 or in the body interior 104 includes a first and a second conductor element 60a, 60b. The first conductor element 60a is arranged in the first winding area 59a of the insulator 100, and can be electrically connected to each other so as to be connected to a common first phase of a power source (not shown). This electrical connection can be achieved axially outside the gap 9 or the stator slot 54. The second conductor element 60b is arranged in the second winding area 59b of the insulator 100, and can be electrically connected to each other so as to be connected to a common second phase of the power source. This electrical connection can also be achieved axially outside the gap 9 or the stator slot 54. Therefore, the first conductor element 60a is electrically insulated from the second conductor element 60b by the interphase insulation portion 108.

[0093] like Figure 5 As shown, the first and second conductor elements 60a, 60b are each implemented as winding strips 65a, 65b, which consist of an electrically conductive material due to their strip-shaped embodiment and are in a mechanically rigid form. In a cross section perpendicular to the axial direction A, the winding strips 65a, 65b each have the geometry of a rectangle 66 with two narrow sides 67 and two wide sides 68.

[0094] The first channel area 107a with the first cooling channel 10 is arranged in the radially inner end 56a of the gap 9 with respect to the radial direction R. Therefore, the second channel area 107b with the second cooling channel 10 is arranged in the radially outer end 56b of the gap 9 with respect to the radial direction R. Therefore, the two winding areas 106a, 106b are arranged between the two channel areas 107a, 107b. Therefore, from the radial inside to the radial outside in the radial direction R, the first channel area 107a with the first cooling channel 10 is followed by the first winding area 106a with the first conductor element 60a. In the radial direction R, the first winding area 106a is followed by the second winding area 106b with the second conductor element 60b, which is in turn followed by the second channel area 107b with the second cooling channel 10.

[0095] like Figure 5 As further shown, a first heat transfer layer 112a consisting of plastic 11 can be arranged in a cross section perpendicular to the axial direction A between the first and / or second conductor elements 60a, 60b of the stator winding 6 and the insulation 100. Figure 5 As shown, the first heat transfer layer 112a can also be arranged between two adjacent conductor elements 60a, 60b. Preferably, all first and second conductor elements 60a, 60b are surrounded in a cross section perpendicular to the axial direction A by the plastic 11 .

[0096] As an alternative or in addition to the first heat transfer layer 112A, in a cross section perpendicular to the axial direction A, a (second) heat transfer layer 112 b consisting of plastic 11 can be arranged between the respective cooling channel 10 and the insulating body 100 .

[0097] like Figure 5 As shown, a spacer structure 113 is formed on the outer wall 101a, 101c, 101d of the insulator 100, by which the outer wall 101a, 101c, 101d can be arranged at a distance from the stator teeth 8a, 8b and / or the stator body 7 in the gap 9. Advantageously, the spacer structure 113 is formed by a protrusion 114 arranged on the outer side of the corresponding outer wall 101b, 101c, 101d, which faces away from the main body interior 104 of the insulator 100. Particularly advantageously, the protrusion 114 can be integrally formed on the corresponding outer wall 101a, 101c, 101d. Therefore, the spacer structure 113 is supported on the stator teeth 8a, 8b and the stator body 7. In a simplified variant of this example, the spacer structure 113 can be omitted.

[0098] The gap 61 formed between the outer wall 101b, 101c, 101d and the stator teeth 8a, 8b and / or the stator body 7 can be filled with a third heat transfer layer 112c composed of plastic 11. This means that, as an alternative or in addition to the first and / or second heat transfer layer 112a, 112b, a third heat transfer layer 112c composed of plastic 11 can be arranged between the insulator 100 and the stator body 7, wherein two adjacent stator teeth are in a cross section perpendicular to the axial direction A.

[0099] like Figure 5 As indicated by the dashed lines in FIG. 1 , a further cooling channel 10 ′ can be formed and arranged in the stator body 7 , which is radially adjacent to the gap 9 on the inside. Such an additional cooling channel 10 ′ can be realized in the form of a hole or perforation.

[0100] Figure 6 Shows Figure 5 Only the differences between the two variants are explained below. Figure 6 , a support structure 120 can be formed on those surface portions of the two stator teeth 8a, 8b and the stator body 7 facing the gap 9, on which the outer walls 101b, 101c, 101d of the insulator 100 can be supported. The support structure 120 can also be formed by a protrusion 121 extending from the stator teeth 8a, 8b and / or from the stator body 7 into the gap 9 in a manner similar to the spacer structure 113 of the insulator 100. The protrusion 121 of the support structure 120 can be integrally formed on the two stator teeth 8a, 8b and / or on the stator body 7.

[0101] Figure 7 Shows Figure 5 Another variation of the example of . Only the differences between the two variations are explained below. Figure 7 In the example of , in a cross section perpendicular to the axial direction A, the insulator 100 has a trapezoidal geometry with a non-right-angled intermediate angle between two adjacent outer walls 101a, 101b, 101c, 101d. In addition, a stator winding 6 having a flexible conductor element 60c is arranged in a single winding zone 106a. Figure 7 In the example of , two cooling channels 10 are provided, wherein the first cooling channel 10 is arranged in the radially inner end 56a of the gap 9, and the second cooling channel 10 is arranged in the radially outer end 56b of the gap 9. Therefore, the first channel area 107a of the insulator 100 having the first cooling channel 10 is arranged in the region of the radially inner end 56a. Thus, the second channel area 107b having the second cooling channel 10 is arranged in the region of the radially outer end 56b of the gap 9. Figure 7In a variant of , the insulator 100 is formed such that it is radially open on the inside, that is to say towards the gap 9 or the opening 52 of the stator slot 54. This means that the outer wall 101a of the insulator 100 is omitted.

[0102] like Figure 7 As shown, the partition wall 105b is only provided between the winding area 106a and the second channel area 107b. In contrast, such a partition wall is omitted between the winding area 106a and the first channel area 107a. In one variant, such a partition wall can also be provided here. Therefore, in another variant, it is possible to omit Figure 7 The outer wall 105c shown in FIG. Further combination possibilities are Figure 7 This is obvious to technicians in the relevant field and will not be explained explicitly.

[0103] In the exemplary case, the plastic 11 of the first heat transfer layer 112a is formed from a first electrically insulating plastic material K1, the plastic 11 of the second heat transfer layer 112b is formed from a second electrically insulating plastic material K2, and the plastic 11 of the third heat transfer layer 112c is formed from a third electrically insulating plastic material K3. The plastic 11 of the electrical insulator 100, in particular the plastic of the outer walls 101a-101d of the electrical insulator 100, is formed from a fourth, likewise electrically insulating plastic material K4.

[0104] In the example in the figure, the fourth plastic material K4 of the insulator 100 is a thermosetting plastic, while the first, second and third plastic materials K1, K2, K3 of the three heat transfer layers 112a, 112b, 112c are thermoplastics. It goes without saying that in its variants, other distributions of thermoplastics and thermosetting plastics of the four plastic materials K1, K2, K3, K4 are also possible. In the exemplary case, the first, second and fourth plastic materials K1, K2, K4 each have a higher thermal conductivity than the third plastic material K3. In this way, an effective heat transfer from the stator winding 6 to the cooling channel 10 is ensured. In the example in the figure, the four plastic materials K1, K2, K3, K4 are different materials. In this case, the thermal conductivity of all four plastic materials K1, K2, K3, K4 is at least 0.5 W / m K, preferably at least 1 W / m K.

[0105] In the following, again refer to Figure 3 ,according to Figure 1 The stator 2 having the stator body 7 and the stator teeth 8 is axially arranged between the first end shield 25a and the second end shield 25b.

[0106] like Figure 3As shown, a portion of the coolant distribution chamber 4 is arranged in the first end shield 25a, and a portion of the coolant collecting chamber 5 is arranged in the second end shield 25b. Therefore, the coolant distribution chamber 4 and the coolant collecting chamber 5 are respectively partially formed by cavities 41a, 41b provided in the plastic composition 11. Here, the first cavity 41a is supplemented by the cavity 42a implemented in the first end shield 25a to form the coolant distribution chamber 4. Correspondingly, the second cavity 41b is supplemented by the cavity 42b implemented in the second end shield 25b to form the coolant collecting chamber 5. Therefore, in the above-mentioned embodiment variant, the plastic 11 at least partially defines the coolant distribution chamber 4 and the coolant collecting chamber 5.

[0107] Furthermore, the coolant supply 35 can be implemented in the first end shield 25a and fluidically connect the coolant distribution chamber 4 to the outer side arranged on the first end shield 25a, in particular to the outer side arranged on the first end shield 25a. Figure 1 The coolant inlet 33 on the circumferential side is shown in FIG. Accordingly, the coolant discharge 36 can be implemented in the second end shield 25b and connect the coolant collecting chamber 5 to the outer side of the end shield 25b, in particular to the coolant collecting chamber 5 arranged on the outer side of the end shield 25b. Figure 1 The coolant outlet 34 on the circumferential side is shown. As a result, the coolant distribution chamber 4 and / or the coolant collecting chamber 5 can be arranged radially on the outside of the first and / or second end 14a, 14b of the respective stator winding 6 and also in the extension of the end 14a, 14b in the axial direction A. The ends 14a, 14b of the stator winding 6, which are particularly exposed to thermal loads during operation of the machine 1, are also cooled particularly effectively by this measure.

[0108] according to Figure 3 The plastic 11 can also be arranged on the outer circumferential side 30 of the stator body 7 and thus can form a plastic coating 11.1 on the outer circumferential side 30. Thus, the stator body 7 of the stator 2, which is typically formed by an electrically conductive stator plate, can be electrically insulated from the surrounding environment. It is thus possible to avoid providing a separate housing for accommodating the stator body 7.

[0109] Figure 1 , 2 , 4, 5, 6 and 7 further show that the insulator 100 is formed so that it can be inserted into the stator slot 54 of the stator 2 along the axial direction a. In this case, according to the example shown, the insulator 100 is formed so that it can be inserted into the stator slot 54 in a precise fit. In this case, the insulator 100 is formed in such a way that the insulator 100 can be inserted into the stator slot 54 in an interference fit or transition fit. Of course, this presupposes that Figure 4 , 56 and the corresponding fit between the insulator 100 and the stator slot 54 into which the insulator 100 can be inserted or inserted. The insulator 100 is formed in a dimensionally rigid manner. In this case, advantageously, the insulator 100 is formed of a dimensionally rigid material. The insulator 100 is reinforced by means of partition walls 105a, 105b, 105c. This means that, in addition to dividing the main body interior 104, the partition walls 105a, 105b, 105c also complete the task of mechanically reinforcing the insulator 100. The insulator 100 is manufactured in a non-molded manner according to the example shown. In addition, it is obvious that the cross section defined perpendicular to the axial direction a of the main body interior 104 of the insulator 100 is constant within the range of the insulator 100. In this case, the length of the insulator 100 extends along the axial direction a.

[0110] Figure 1 , 2 , 4, 5 and 6 also show that the cross section of the insulator 100 defined perpendicular to the axial direction a is both axially symmetrical and point symmetrical. The outer walls 101a, 101b, 101c, 101d of the insulator are connected to each other. According to the example shown, the outer walls 101a, 101b, 101c, 101d of the insulator 100 are connected to each other without seams and / or joints.

Claims

1. An insulator (100) for an electric machine (1), The invention relates to a main body having an outer wall (101a, 101b, 101c, 101d) made of plastic (K), which defines a main body interior (104), in which at least one winding area (106a, 106b) for accommodating a stator winding (6) and at least one channel area (107a, 107b) for accommodating a cooling channel are arranged, wherein: The insulator (100) is formed so that it can be inserted into a stator slot (54) along an axial direction (a).

2. The insulator (100) according to claim 1, It is characterized in that The insulator (100) has at least one partition wall (105a, 105b, 105c) made of plastic (K), which divides the body interior (104) into the at least one winding area (106a, 106b) and at least one channel area (107a, 107b).

3. The insulator (100) according to claim 1 or 2, It is characterized in that - the outer wall (101a-101d) and the at least one partition wall (105a-105c) extend along the axial direction (a); - In a cross section perpendicular to the axial direction (a), the at least one winding zone (106a, 106b) and the channel zone (107a, 107b) are arranged adjacent to each other.

4. The insulator (100) according to claim 1 or 2, It is characterized in that - the presence of two channel areas (107a, 107b) for accommodating the first and second cooling channels, In a cross section perpendicular to the axial direction (a), the at least one winding zone (106a, 106b) is arranged between two channel zones (107a, 107b) and is separated from the two channel zones by means of two partition walls (105a, 105b).

5. The insulator (100) according to claim 1 or 2, It is characterized in that - providing two winding zones (106a, 106b) which are arranged adjacent to each other in a cross section perpendicular to the axial direction (a), The winding zones (106a, 106b) are separated from one another by means of an interphase insulation (108) made of plastic (K).

6. The insulator (100) according to claim 5, It is characterized in that The interphase insulating portion (108) is formed by a partition wall (105c) of the insulator (100).

7. The insulator (100) according to claim 1 or 2, It is characterized in that - the insulator (100) is an injection molded part; or / and - the insulator (100) is a monolithic body; or / and the insulator (100) is an extruded body.

8. The insulator (100) according to claim 1 or 2, It is characterized in that The insulator (100) has a parallelepiped geometry; or / and The insulator (100) has a trapezoidal geometry in a cross section perpendicular to the axial direction (a).

9. The insulator (100) according to claim 1 or 2, It is characterized in that An axial stopper (109) is formed on at least one outer wall (101a-d) at an axial end (111) of the insulator (100).

10. The insulator (100) according to claim 9, It is characterized in that The axial stopper (109) is formed as an outwardly protruding wall protrusion ring (110), and the wall protrusion ring is formed on at least one outer wall (101a-d) of the insulating body (100).

11. The insulator (100) according to claim 1 or 2, It is characterized in that A spacer structure (113) is provided on at least two outer walls (101b-d), by means of which the outer walls (101a-d) can be inserted at a defined distance into stator slots (54) of a stator (2) of an electric machine (1).

12. The insulator (100) according to claim 11, It is characterized in that The spacer structure (113) is formed by a projection (114) arranged on the outer side of the respective outer wall (101b-101d) facing away from the body interior (104).

13. The insulator (100) according to claim 12, It is characterized in that The protrusion (114) is integrally formed on the associated outer wall (101a-d).

14. The insulator (100) according to claim 1, It is characterized in that The insulator (100) is formed so that it can be inserted into the stator slot (54) in a precise fit.

15. The insulator according to claim 1 or 2, It is characterized in that The insulator (100) is formed in a dimensionally rigid manner.

16. The insulator (100) according to claim 1 or 2, It is characterized in that The insulation (100) is reinforced by means of partition walls (105a, 105b, 105c).

17. The insulator (100) according to claim 1 or 2, It is characterized in that The insulator (100) is manufactured in a non-molding manner.

18. The insulator (100) according to claim 1 or 2, It is characterized in that A cross section of the main body interior (104) of the insulator (100) defined perpendicularly to the axial direction (a) is constant within a range of the insulator (100) extending along the axial direction (a).

19. The insulator (100) according to claim 1 or 2, It is characterized in that A cross section of the insulator (100) defined perpendicular to the axial direction (a) is both axially symmetrical and point-symmetrical within the insulator (100).

20. The insulator (100) according to claim 1 or 2, It is characterized in that The outer walls (101a, 101b, 101c, 101d) are connected to each other.

21. The insulator (100) according to claim 2, It is characterized in that The plastic (K) is an electrically insulating plastic.

22. The insulator (100) according to claim 1 or 2, It is characterized in that The insulator (100) has a rectangular geometry in a cross section perpendicular to the axial direction (a).

23. The insulator (100) according to claim 9, It is characterized in that The axial stopper (109) is formed as an outwardly protruding wall protrusion ring (110), which is integrally formed on at least one outer wall (101a-d) of the insulator (100).

24. The insulator (100) according to claim 14, It is characterized in that The precise fit is an interference fit or a transition fit.

25. The insulator (100) according to claim 1 or 2, It is characterized in that The insulator (100) is formed of a dimensionally rigid material.

26. The insulator (100) according to claim 1 or 2, It is characterized in that The outer walls (101a, 101b, 101c, 101d) are connected to each other without seams and / or joints.

27. An electric motor (1), - comprising a rotor (3) and comprising a stator (2) having an electrically conductive stator winding (6), said rotor being rotatable about an axis of rotation (D) defining an axial direction (A) of said electrical machine (1), - comprises at least one cooling channel through which a coolant (K) can flow for cooling the stator winding (6), -in, The stator (2) has stator teeth (8) which extend along the axial direction (A) and are arranged at a distance from each other along the circumferential direction (U) of the rotor (3), the stator teeth protrude from a stator body (7) of the stator (2) and carry the stator winding (6), - wherein a gap (9) is formed between two stator teeth (8, 8a, 8b) adjacent to each other in the circumferential direction (U), - wherein an insulator (100) according to any one of the preceding claims is arranged in at least one gap (9), - wherein a stator winding (6) is arranged in at least one winding region (106a, 106b) of the insulator (100), and a cooling channel for a coolant (K) to flow through is arranged in at least one channel region (107a, 107b) of the insulator (100).

28. The electric machine (1) according to claim 27, It is characterized in that The insulator (100) is inserted into the gap (9).

29. The electric machine (1) according to claim 27 or 28, It is characterized in that The axial direction (a) of the insulator (100) extends parallel to the axial direction (A) of the motor (1).

30. The electric machine (1) according to claim 27, It is characterized in that The electric machine is used in a motor vehicle.

31. The electric machine (1) according to claim 27, It is characterized in that The stator teeth protrude radially inwardly from a stator body (7) of the stator (2).

32. A motor vehicle comprising an electric machine (1) according to any one of claims 27 to 31.

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