DE102019008668A1 - Stator device for an electrical machine with a separate cooling device and electrical machine - Google Patents

Abstract

The invention relates to a stator device (10) for an electrical machine (12), with a stator element (14) which is designed to be arranged around a rotor of the electrical machine (12), with at least one groove (16) in which at least one Winding element (18) of the stator device (10) is arranged, and with a cooling device (20) arranged in the groove (16) with at least one first cooling channel (22) for fluidic cooling of the at least one winding element (18), wherein the cooling device (20 ) is designed as a separate component to the groove (16) and / or the cooling device (20) has at least one second cooling channel (24), which is formed by a raised rib element (26) of the cooling device (20), which at least partially covers the winding element (18) touches, is fluidically separated from the first cooling channel (22). The invention also relates to an electrical machine (12).

Description

The invention relates to a stator device for an electrical machine according to the preamble of patent claim 1. The invention also relates to an electrical machine.

It is known from the prior art that very high demands are placed on electrical drive trains, in particular in motor vehicles, in terms of, for example, duration and torque or duration and power density with a high degree of efficiency at the same time. These goals, the highest possible torque and power density, can be achieved in particular by a corresponding cooling capacity of the electrical machine.

The EP 1 251 624 B1 discloses a stator for an air-gap electrical machine, the stator comprising an outer annular laminated stator core coaxial with a longitudinal axis of the machine and a stator winding on the inside of the stator core and a plurality of turns with rectilinear conductor sections, comprising a plurality of holders for the turns, wherein the brackets extend along the rectilinear conductor sections of the turns, the brackets being made of non-magnetic material and each bracket being disposed between and in contact with two adjacent rectilinear conductor sections of the turns. It is provided that at least some of the brackets define channels for a coolant flow along them in order to thereby dissipate heat from the windings, and wherein the straight conductor sections of the multiple windings are arranged in two layers which are positively joined together at a profile interface between two corresponding layers of the brackets to provide mechanical strength.

Furthermore, the DE 25 29 914 a cooling device for electrical machines using a volatile liquid suitable for evaporation in an evaporator, the evaporator absorbing the heat given off by the organs to be cooled, where furthermore the vapor condenses in a suitably cooled condenser and the condensation liquid flows back into the evaporator , wherein an evaporator, which is inserted into the grooves of the electrical machine, the interior of this evaporator is divided by a perforated partition into two chambers, of which the first chamber is filled with a cellular material traversed by a network of capillary channels, wherein the channels are connected to each other and open to the outside, as well as a connecting channel which is divided alongside by a partition into two chambers, the first chamber containing a cellular material which is analogous to the cellular material in the evaporator and is permeated by capillary communicating channels, and the like nd the first and second chambers of said channel are continuously connected to the corresponding first and second chambers of the evaporator. Furthermore, a condenser is disclosed, the interior of which is also divided into two chambers by a perforated partition, the first chamber containing a cellular material which is analogous to the cellular material in the evaporator and traversed by capillary communicating channels, and the first and second chambers of this condenser with the corresponding first and second chamber of the connecting channel is continuously connected.

Furthermore, the DE 24 40 132 a cooling device for the rotor of an electrical machine, in particular a synchronous machine, which is provided with longitudinal grooves, in each of which a deeply cooled winding section of an excitation winding is arranged, which is provided with at least one coolant supply and drainage, each winding section over its entire axial Length is penetrated by a plurality of at least approximately in the circumferential direction of the rotor, individual cooling channels and which also a plurality of at least approximately radially extending, individual coolant supply lines and / or discharge lines are provided for each winding section, which are connected to the cooling channels.

Furthermore, the DE 1 014 640 a stator winding for a dynamoelectric machine which comprises conductors passing through slots in an iron core and arranged in the core in upper and lower groups, which have longitudinal channels through which a coolant flows from one end to the other of the machine and which extend over the two Ends of the iron core extend out and are supported insulated at the distance from the core end points, each conductor comprising two conductor strips which are spaced apart to form a coolant channel between them, and connectors in the form of metal strips, which enclose the conductors at points between the ends of the iron core and the insulated supports, interconnecting the conductors of the upper and lower groups.

Furthermore, the US 2014/0292118 A1 a stator winding on a stator on a stator core. The stator winding has a portion which is rectangular in shape and which includes a plurality of conductors electrically connected to one another. Each of the conductors has in-slot sections which are stacked in corresponding slots when the winding is wound on the stator core. A fastener fixes the groove sections to each of the slots. The fastener consists of an adhesive material which is filled into each of the slots in such a way that a through hole remains through each of the slots in the axial direction. The refrigerant may get through the through hole.

The object of the present invention is to create a stator device and an electrical machine which have a higher power density.

This object is achieved by a stator device and by an electrical machine according to the independent patent claims. Advantageous embodiments are specified in the subclaims. One aspect of the invention relates to a stator device for an electrical machine with a stator element which is designed to be arranged around a rotor of the electrical machine, with at least one slot in which at least one winding element of the stator device is arranged, and with a cooling device arranged in the slot with at least one first cooling channel for fluidic cooling of the at least one winding element.

It is provided that the cooling device is designed as a separate component to the groove and / or the cooling device has at least one second cooling channel, which is fluidically separated from the first cooling channel by a raised rib element of the cooling device which at least partially contacts the winding element.

This enables a performance density of the electrical machine to be increased. In particular, an improvement in performance, an improvement in torque and an improvement in the efficiency can be realized.

In particular, in order to be able to cool the copper losses in the stator even better, on the one hand to increase the continuous power and on the other hand to increase the efficiency, it is advantageous to cool as close as possible to the heat source. Electrical machines that are directly oil-cooled have a very high continuous power density. However, the oil in the air gap can lead to drag losses. The direct cooling of the conductor in the core of the machine, in other words the winding element, beyond the end windings enables the continuous output to be increased again significantly.

The winding element can in particular be formed from shaped wire HaitPin plug-in windings. Furthermore, wave or loop windings with solid shaped wire as well as twisted and compacted round wire bundles can be used.

According to an advantageous embodiment, the groove widens outward in a radial direction of the stator device.

Furthermore, it has proven to be advantageous if the groove essentially has two groove walls viewed in a radial direction, a first groove wall running essentially parallel to the radial direction and a second groove wall running offset to the radial direction at an acute angle.

It has also proven to be advantageous if the first cooling channel and the second cooling channel are formed on the second groove wall.

Furthermore, it has proven to be advantageous if the at least one winding element is arranged in the groove in such a way that the winding element forms a delimitation for at least one of the cooling channels.

Another aspect of the invention relates to an electrical machine with at least one rotor and with a stator device according to the preceding aspect.

Yet another aspect of the invention relates to a motor vehicle with an electrical machine according to the preceding aspect. The motor vehicle is designed in particular as a passenger vehicle

Advantageous embodiments of the stator device are to be regarded as advantageous embodiments of the electrical machine and the motor vehicle.

Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and on the basis of the drawings. The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination, but also in other combinations or alone, without the scope of the Invention to leave.

• 1 eine schematische Perspektivansicht einer Ausführungsform einer elektrischen Maschine;
• 2 eine schematische Seitenansicht einer Ausführungsform einer Statorvorrichtung;
• 3 eine weitere schematische Seitenansicht einer weiteren Ausführungsform einer Statorvorrichtung; und
• 4 eine weitere schematische Seitenansicht einer weiteren Ausführungsform einer Statorvorrichtung.

Show:

• 1 a schematic perspective view of an embodiment of an electrical machine;
• 2 a schematic side view of an embodiment of a stator device;
• 3 a further schematic side view of a further embodiment of a stator device; and
• 4th a further schematic side view of a further embodiment of a stator device.

Identical or functionally identical elements are provided with the same reference symbols in the figures.

1 shows in a schematic perspective view an embodiment of a stator device 10 for an electric machine 12th . The stator device 10 has a stator element 14th on, which is to be arranged around a rotor, not shown, of the electrical machine 12th is trained. The stator device 10 has at least one groove 16 , in the present embodiment a plurality of grooves 16 , on. In a respective groove 16 is at least one winding element 18th the stator device 10 arranged. Furthermore, there is a respective groove 16 a respective cooling device 20th with at least one first cooling channel 22nd ( 2 ) for fluidic cooling of the at least one winding element 18th educated.

It is provided that the cooling device 20th as a separate component to the groove 16 is formed and / or the cooling device 20th at least one second cooling channel 24 has, which by a raised rib member 26th ( 2 ) the cooling device 20th , which at least partially the winding element 18th touched by the first cooling channel 22nd is separated.

2 shows the stator device in a schematic side view 10 according to the execution, as already in 1 is shown. The 2 shows in particular an enlarged section of FIG 1 . In particular, in 2 to see that the groove 16 a variety of raised rib elements 24 may have. In particular, this makes it possible to have additional cooling channels within the groove 16 be formed.

In particular, shows the 2 that the groove 16 in a radial direction R. the stator device 10 widens outwards. Furthermore, it can be provided in particular that the groove 16 in radial direction R. essentially considers two groove walls 28 , 30th may have, wherein a first groove wall 28 substantially parallel to the radial direction R. runs and the second groove wall 30th at an acute angle α offset to the radial direction R. runs.

Furthermore, in the 2 to see that the first cooling channel 22nd and the second cooling channel 24 on the second groove wall 30th are trained. Furthermore, the 2 that the at least one winding element 18th so in the groove 16 is arranged that the winding element 18th a limitation for at least one of the cooling channels 22nd , 24 forms.

In particular, it is provided that in the cooling channels 22nd , 24 Cooling fluid flows so that the winding element 18th can be advantageously cooled. So that the cooling fluid from leaking out of the groove 16 is protected, the groove can 16 especially with a slot wedge 32 are closed in each case.

In other words, it shows 2 in particular that the inside of the stator slot, in other words the slot 16 , is profiled so that on the one hand the winding element 18th is supported on the flanks and at the same time cavities, in other words the cooling channels 22nd , 24 that arise for cooling the winding element 18th are trained. This enables the iron core of the electrical machine 12th axially, for example, to flow through with dielectric fluid and thus the stator, in other words the stator device 10 and in particular the winding element 18th , right in the core of the electrical machine 12th to cool. In particular, it can be the case with the cooling device 20th be extrusion profiles, which with plug-in technology analogous to the conductors or the winding element 18th axially in the groove 16 be inserted or, in the case of a wave winding, alternatively also radially through the slot opening into the slot 16 can be inserted or clipped. The winding elements can be fixed 18th for example by means of classic soaking in epoxy resin.

In other words, it shows 2 that the cooling device 20th as a separate component in the groove 16 is introduced, which by profiling the cooling channels 22nd , 24 forms, this being in the present embodiment only on one side of the groove 16 , especially on the second groove wall 30th , is trained. The cooling device 20th can be inserted into the groove as a finished component 16 be introduced or, for example, also injected there. In the present case it is provided that the groove 16 is not "rectangular", but, as is known for example with stator teeth, widens radially outwards and is a web 34 between the grooves 16 has parallel walls. In addition, there is a wall of the groove 16 here, as with conventional stators, with rectangular grooves aligned in the radial direction, i.e. pointing towards the center point, in other words in the radial direction R. so that the jetty 34 between the grooves 16 has a parallel shape and the other wall of the groove 16 all the more out of the radial direction, so that the web 34 between the grooves 16 has a parallel shape. This creates a "sloping" groove 16 , one side of which is aligned with the winding as usual and on the other side the profiling defines the free space in which the Cooling channels 22nd , 24 and supports of the winding elements 16 to represent.

The winding element 18th or the winding elements 18th , especially with the cooling device 20th , are down to the rotor, not shown, over the slot wedge 32 completed the winding elements 18th in the groove 16 fixed and especially the groove 16 and the cooling channels 22nd , 24 seals against the air gap, so that the cooling device 20th takes place in the axial direction and does not seep into the air gap. The shape of the slot wedge 32 depends in particular on the shape of the groove and can be held, for example, by web feet.

In other words, in the 2 in particular an asymmetrical design of the groove 16 shown. In particular, shows the 2 furthermore that in addition the cooling device 20th the winding element 18th quite, especially in the entire groove 16 , in particular on three sides thereof, surrounds and not just on one side of the groove 16 is present. In addition, the profiling component, in other words the cooling device 20th , a direct cooling contact with the winding element 18th arise so that the winding element 18th even a limitation of the cooling channel 22nd , 24 forms, whereby no self-contained cooling channel 22nd , 24 is formed.

3 shows a further embodiment of the stator device in a schematic side view 10 . In the 3 is in particular the cooling device 20th provided in such a way that they go directly into the groove 16 can be injected and in particular the winding element 18th holds. The winding element 18th is in particular flowed around by cooling fluid. The winding element 18th is supported in particular on the flanks, and at the same time the cavities for the cooling channels 22nd , 24 be generated. This allows the iron core of the electrical machine 12th axially, for example, dielectric fluid flows through it and thus the stator device 10 and in particular the winding element 18th cool directly in the core of the machine. Here, too, the cooling device 20th especially through plug-in technology analogous to the winding element 18th axially in the groove 16 be inserted or, in the case of a wave winding, alternatively also radially through the slot opening into the slot 16 inserted or clipped. In other words, the groove is also profiled here 16 by the separate component, in other words the cooling device 20th , proposed, this being in particular an electrically insulating component, so that further insulation is not required here. The cooling device 20th can already be prefabricated and before or with the first winding in the groove 16 be introduced, or it can be in the groove 16 injected directly, i.e. generated there. Creating the profile of the groove 16 can be done either by injection or by demolding itself and a two-stage production, in that the profiling bumps are first introduced and then joined together via the injection / covering / sheathing and produced as the final shape. Alternatively, some formations can also be introduced during the manufacture of the winding or afterwards, be it axially or radially inserted, depending on the shape of the winding and the profile or groove shape.

4th shows an embodiment of the stator device in a further schematic side view 10 . In particular, it can be seen that the cooling device 20th Is formed x-shaped, the corresponding cooling channels through the x-shape 22nd , 24 are formed. The cooling device 20th can be designed as an extrusion profile, for example made of plastic. In the present embodiment, the entire groove is therefore not used 16 with the winding element 18th filled, but individual conductors are replaced, for example, by plastic extrusion profiles. This makes it possible for dielectric fluid, for example, to flow axially through the iron core of the electrical machine and thus through the stator device 10 and in particular the winding element 18th to cool directly in the core of the machine. The extrusion profiles can be inserted axially into the groove using a plug-in technique analogous to the conductors 16 be inserted or, in the case of a wave winding, alternatively also radially through the slot opening into the slot 16 be inserted. In other words, it shows 4th that between the winding element 18th a so-called spacer, which is designed in particular in an x-shape, can be introduced, which then forms the cooling channels in the free spaces of the “x” 22nd , 24 forms. Here, the spacer takes the place of a winding stack, in other words a winding element 18th , so that the fill factor and thus the magnetic power can be reduced, but this can be compensated for by improved cooling and the associated higher stress.

Overall, the invention shows direct stator cooling by means of a profiled stator slot.

List of reference symbols

10

Stator device

12th

electric machine

14th

Stator element

16

Groove

18th

Winding element

20th

Cooling device

22nd

first cooling channel

24

second cooling channel

26th

raised rib element

28

first groove wall

30th

second groove wall

32

Slot wedge

34

web

R.

Radial direction

α

acute angle

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1251624 B1 [0003]
• DE 2529914 [0004]
• DE 2440132 [0005]
• DE 1014640 [0006]
• US 2014/0292118 A1 [0007]

Claims (6)

Stator device (10) for an electrical machine (12), with a stator element (14), which is designed to be arranged around a rotor of the electrical machine (12), with at least one slot (16) in which at least one winding element (18) the stator device (10) is arranged, and with a cooling device (20) arranged in the groove (16) with at least one first cooling channel (22) for fluidic cooling of the at least one winding element (18), characterized in that the cooling device (20) is designed as a separate component for the groove (16) and / or the cooling device (20) has at least one second cooling channel (24) which is in contact with the winding element (18) through a raised rib element (26) of the cooling device (20), which at least in some areas , is fluidically separated from the first cooling channel (22). Stator device (10) after Claim 1 , characterized in that the groove (16) widens outwards in a radial direction (R) of the stator device (10). Stator device (10) after Claim 1 or 2 , characterized in that the groove (16), viewed in a radial direction (R), has essentially two groove walls (28, 30), a first groove wall (28) running essentially parallel to the radial direction (R) and a second groove wall ( 30) runs at an acute angle (a) offset to the radial direction (R). Stator device (10) after Claim 3 , characterized in that the first cooling channel (22) and the second cooling channel (24) are formed on the second groove wall (30). Stator device (10) according to one of the preceding claims, characterized in that the at least one winding element (18) is arranged in the slot (16) in such a way that the winding element (18) forms a delimitation for at least one of the cooling channels (22, 24) . Electrical machine (12) with at least one rotor and with a stator device (10) according to one of the Claims 1 to 5 .

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