INSULATION DEVICE WITH COOLING MEDIUM LINE

Description

Technical area

[0001] The invention relates to an insulating device with a cooling medium line, which is used to dissipate heat loss from a stator of an electric machine.

[0002] Furthermore, the invention relates to the use of the insulating device on an electric motor of a vehicle having at least one electric motor. State of the art

[0003] DE 10 2012 021 600 A1 relates to an electric motor. The electric motor comprises a housing with a stator, a rotor, and a rotary transformer. The rotary transformer has a primary-side first device with a primary winding and a secondary-side second device with a secondary winding. The housing has a first receptacle for positioning the primary-side first device. The primary-side first device comprises a number of first fastening points for non-positive and / or positive fastening to the housing. The rotor comprises a second receptacle for positioning the secondary-side second device, wherein the secondary-side second device has a number of second fastening points for non-positive and / or positive fastening to the rotor.The rotor contains a first connection device, and the secondary-side second device contains a second connection device for electrically connecting the rotor to the secondary-side second device. The first connection device has first electrical contact elements, and the second connection device has second electrical contact elements for detachable line connections by means of positive locking and / or frictional locking.

[0004] DE 10 2015 216 055 A1 relates to the cooling system of an electrical machine. The cooling system comprises at least one bearing plate and at least one coolant distribution plate, wherein the bearing plate and the coolant distribution plate are configured to jointly form a cooling channel. The cooling channel comprises a plurality of horizontal cooling channel sections that run parallel to a rotational axis of the electrical machine. Furthermore, the cooling channel comprises a plurality of vertical cooling channel sections that run perpendicular to the rotational axis of the electrical machine. Furthermore, a plurality of radially extending cooling channel sections are provided, which extend around the rotational axis of the electrical machine.

[0005] DE 11 2012 002 552 T5 relates to an electric motor. The electric motor comprises a shaft provided with a rotor having a coolant passage formed therein for allowing a cooling medium to flow therethrough. Furthermore, a housing is provided in which the shaft is disposed, the shaft being rotatably supported. A cooling medium supply section is provided within the housing on one side of one end of the shaft and supplies the cooling medium to the internal cooling medium passage. Furthermore, a rotation angle detection sensor is provided, which is mounted on the side of one end of the shaft and detects a rotation angle of the shaft.

[0006] US 2018 002 6493 A1 relates to a housing for an electric motor. A housing for an electric motor includes a housing body having an inner part and an outer part, which together form a cooling medium path extending in the axial direction of the housing body. A power component portion protruding from the outer surface of the outer housing part is formed such that the power component is cooled by the cooling medium. Housing covers are arranged at both end portions of the housing body so that the electric machine and the power component are simultaneously cooled via the one cooling fluid flow path. This eliminates the need for a separate power component housing for arranging the power component, thereby reducing the size and weight of the housing.

[0007] US 3,808,489 relates to a cooled cover for a generator terminal section. The terminal section for high-voltage terminals of a dynamoelectric machine is equipped with special arresters to prevent overheating of the terminal area walls due to circulating currents emanating from the high-voltage terminals. The shields and the terminal area are cooled by a gas flowing between them through suitable channels.

[0008] US 5,814,909 relates to an electric motor comprising a heat radiator at an electrical connection to an inverter. The coils of the electric motor are electrically connected to the power electronics of an inverter. A conductor section that supplies traction current to the motor coils comprises a first heat radiation region or other heat radiation element within the conductor path. In this way, the heat generated by the electric motor is conducted from the conductor section into the conductor path. The power device and other components of the inverter can thereby be protected from thermally induced damage or from weathering phenomena caused by the heat generated by the motor coils and conducted to the inverter through the conductor section, which has a higher thermal conductivity.

[0009] JP 04 265 614 A refers to phase insulation with forced air cooling.

[0010] The (three-phase) electric motors used on electric drive axles, for example, require an electrical connection between the stator phases to operate. If longer distances must be covered to reach the control electronics, the phase currents are routed via copper busbars. These busbars have a relatively large cross-section to keep ohmic resistance and heating as low as possible. To maintain the required clearance and creepage distances, the busbars are enclosed in a plastic insulating piece.

[0011] To dissipate waste heat, the stator of the electric motor is often water-cooled. The cooling water is supplied and removed, for example, in the area of ​​the bearing shield. Between these connection points, the cooling water is routed to the heat absorption in the machine housing. Since connecting the internal cooling water system and the desired connection direction of the cooling water hoses often requires awkwardly curved supply lines, which are very complex to produce using casting technology, they are usually formed with attached plastic or metal pipes. Description of the invention

[0012] According to the invention, an insulating device with integrated cooling medium channels is proposed, which comprises an insulating body made of a plastic material in which busbars are accommodated. The cooling medium channels are integrated into the plastic material of the heat sink. The solution proposed according to the invention advantageously avoids the otherwise complex cooling water duct, particularly when manufactured as cast components. The solution proposed according to the invention advantageously reduces the temperature level of the busbars on the insulating device.

[0013] The insulating device can be designed either in a single-piece design or in a multi-piece design.

[0014] The integrated cooling medium channels are molded onto the end face of the insulating body of the insulating device proposed according to the invention. The molding of the cooling medium channels from the plastic material from which the insulating body is made can be achieved in a particularly simple manufacturing process using the injection molding process for a plastic material.

[0015] Advantageously, the cooling medium channels on the insulating body of the insulating device run in such a way that they extend essentially in the vertical direction.

[0016] By means of the solution proposed according to the invention, the busbars which are embedded in the insulating body can be advantageously insulated from one another and pipe bends in which the cooling medium flows can be integrated into the insulating body of the insulating device.

[0017] The insulating body of the insulating device proposed according to the invention is made of an electrically insulating plastic material optimized for the best possible thermal conduction. This is, for example, a plastic material such as Luvocom 1-8259 or Tecacomp PA 66 TC 3923. The solution proposed according to the invention advantageously avoids the production of complicated cooling medium channels through mold cores or intersecting bores, without requiring additional components such as separate connecting pieces and the like. The solution proposed according to the invention enables particularly space-saving and simple cooling of the busbars, so that the ohmic resistance and heating of the busbars are kept as low as possible under high loads.

[0018] The insulating device proposed according to the invention can be designed either in a single-piece design or in a multi-piece design. In the case of a multi-piece design, for example, the individual parts of the insulating body can be made from different plastic materials. Alternatively, it is also possible to manufacture the two parts of a multi-piece design of the insulating body from one and the same plastic material. The parts of the insulating body - in the case of a multi-piece design - lie against one another along a parting line, with two busbars being arranged in a first part of the insulating body in the case of a multi-piece design, for example, and only one busbar being arranged in a second part of the insulating body that is designed complementarily to the first part, or vice versa.

[0019] In the case of a one-piece design of the insulating body of the insulating device proposed according to the invention, said body can advantageously be made of one material, wherein in particular the integrated cooling medium channels are injection-molded onto the front side of the insulating device.

[0020] Instead of flat-designed busbars, stamped from sheet metal, or otherwise formed, various types of wires can be used. For example, solid wire with a round or other cross-section can be used, as can stranded or braided wires. When using busbars designed in this way, the corresponding receiving geometry in the material of the insulating body is complementary to the geometry of the respective busbar. The thermal coupling of the conductors to the plastic surface of the insulating body can be improved with thermal paste, which applies to both flat-design busbars and wire-form busbars—as explained above.

[0021] The invention further relates to the use of the insulating device with integrated cooling medium channels for cooling an electric motor of a vehicle having at least one electric motor, be it an electric vehicle (EV), a hybrid electric vehicle (HEV), or a plug-in hybrid electric vehicle (PHEV). Advantageously, for example, when using the solution proposed by the invention in hybrid electric vehicles, the cooling medium circuit of the internal combustion engine can simultaneously be used to cool the at least one electric motor of a hybrid electric vehicle, without a separate cooling medium circuit being required in a hybrid electric vehicle. Advantages of the invention

[0022] The solution proposed by the invention advantageously offers a way to simplify the manufacture of housing parts for electric motors, since the solution proposed by the invention avoids the production of complicated cooling medium channels through mold cores on cast parts or intersecting bores on cast parts, without the need for additional components such as separate connecting pieces or the like. The solution proposed by the invention allows the busbars guided in the insulating body of the insulating device to be cooled very simply and efficiently and maintained at a low temperature value that advantageously promotes the ohmic resistance. The solution proposed by the invention allows a significant reduction in the effort that would otherwise be required with regard to the cooling medium guidance.The insulation device proposed by the invention with integrated cooling medium channels can reduce the temperature level in the area of ​​the busbars on the insulating body. Furthermore, the solution proposed by the invention enables efficient and reliable electrical insulation of the busbars from one another. In contrast to previously used solutions involving pipe bends and the like, which require subsequent insulation, the solution proposed by the invention reduces the number of components, eliminates the need for seals, and, in particular, ensures leak-free cooling medium flow.

[0023] The solution proposed according to the invention is characterized by a weight saving compared to a solution in which the entire channel guide runs in a bearing plate made of aluminum and this has to be dimensioned accordingly larger. Short description of the drawings

[0024] The invention is described in more detail below with reference to the drawing.

[0025] It shows: Figure 1a perspective view of an E-axis module with a bearing plate for an electrical machine and power electronics, Figure 2a perspective top view of a previously used insulating piece including busbars, Figure 3a view of a Figure 1 installed pipe bend, Figure 4 shows a first one-piece embodiment of the insulating device proposed according to the invention with cooling medium channels integrated on the front side, Figure 5 shows a multi-part embodiment of the insulating device proposed according to the invention with integrated cooling medium channels and Figure 6 shows a first part of the Figure 5 Insulating device according to the invention shown in a multi-part embodiment. Versions

[0026] The representation in Figure 1 A perspective view of an e-axis module can be seen.

[0027] The representation according to Figure 1 shows a side perspective view of an electric axle module, in particular showing a bearing plate 12 of a housing. Above the bearing plate 12, which largely conceals an electric motor 14, a part of a power electronics unit 10 is shown. On the power electronics unit 10, Figure 1 not shown electrical connections are included, through which the Figure 1 is supplied with power by an electric motor 14 (not shown). Phase connections 16 extend from the electric motor 14 to a first busbar 18, a second busbar 20, and a third busbar 22.

[0028] Furthermore, according to the perspective view Figure 1that a cooling medium guide 24 comprises a pipe bend 26. This is, for example, an inlet 28 for a cooling medium, while the Figure 1 The return line 30, also shown in perspective view, serves to return the cooling medium.

[0029] Figure 2 shows a perspective view of an insulating piece 32. The insulating piece is enclosed by a border and comprises individual insulating webs 34, which separate the first busbar 18 from the second busbar 20 and the second busbar 20 from the third busbar 22. The insulating piece 32 has an insulating piece trough 36, which is enclosed by the border. The insulating pieces 34 extending through the insulating piece 32 insulate the first busbar 18, the second busbar 20, and the third busbar 22 from one another.

[0030] Figure 3shows a perspective view of a pipe bend 26, which is made, for example, of a metallic material and which conducts cooling medium to the bearing plate 12 on which the electric motor is mounted.

[0031] Figure 4 shows a first embodiment of the insulating device proposed according to the invention with integrated cooling medium channels.

[0032] From the representation according to Figure 4 It can be seen that an insulating body 74, in which the first busbar 18, the second busbar 20 and the third busbar 22 are insulated from each other, is made, for example, of a first plastic material 52. In the illustration according to Figure 4It is an insulating body 74 made of a first plastic material 52. For manufacturing reasons, the plastic injection molding process is preferred for the manufacture of the insulating body 74 with regard to the first channel 44 and the second channel 46. The first plastic material 52 is, for example, an electrically insulating plastic material optimized for the best possible thermal conduction, such as Luvocom 1-8259 or Tecacomp PA 66 TC 3923.

[0033] From the representation according to Figure 4It can be seen that the insulating body 74 of the insulating device 40 is formed in a one-piece design 50. The insulating body 74 is preferably manufactured in a single operation using the plastic injection molding process. The respective insulating webs 34, surrounded by a border 48, can also be manufactured during plastic injection molding. The insulating webs 34, which extend through the interior of the insulating body 74, electrically insulate the first busbar 18 from the second busbar 20, and the second busbar 20 from the third busbar 22. The first, second, and third busbars 18, 20, 22 each comprise connection regions 72, which can be provided, for example, with a circular opening or the like.

[0034] Out of Figure 4It further follows that the first channel 44 and the second channel 46 extend substantially in the vertical direction 76 on the end face 42 of the insulating body 74. Preferably, an inflow 54 is placed in the region in which more heat is to be dissipated because, for example, several busbars 18, 20, 22 are arranged there, or the busbars 18, 20, and 22 arranged there are longer, since their effectiveness is greater due to the lower coolant temperature.

[0035] The first busbar 18, the second busbar 20 and the third busbar 22 are shaped in such a way that they have sections that run flat with respect to the bottom of the insulating body 74 as well as sections that run upright and are rotated by 90° relative to these.

[0036] According to the illustration Figure 51 shows a perspective top view of an insulating body 74 which is provided in a multi-part design 59. This is to be understood that in the multi-part design 58 the insulating device 40 proposed according to the invention comprises a first part 64 and a second part 66. While in the exemplary embodiment according to Figure 5 the first part 64 accommodates the first busbar 18 and the second busbar 20, the second part 66 only accommodates the third busbar 22. The orientation of the connection areas 72 of the busbars 18, 20 and 22 changes in the multi-part version 58 according to Figure 5 compared to the one-piece version 50 according to Figure 4 nothing. For example, while the first part 64 of the insulating body 74 is injection-molded from the first plastic material 52, the second part 66 of the insulating body 74 could be injection-molded as shown in Figure 5from a different, second plastic material 60. Both parts, the first part 64 and the second part 66, have in common that the first channel 44 and the second channel 46 are injection-molded onto their mutually parallel end faces 42. With respect to the first part 64, the first channel 44 is located on the end face 42. The second part 66 of the insulating device 40, on the other hand, accommodates the second channel 46 on its end face 42. Analogous to the illustration according to Figure 4 , ie for the one-piece design 50, the two channels 44, 46 on the first part 64 and the second part 66 also run essentially in the vertical direction 76 on the end face 42 of the two parts 64 and 66 lying against one another along a parting line 62.

[0037] At the Figure 5In the illustrated embodiment of the insulating body 74 of the insulating device 40 in a multi-part design 58, the injection molding tool in which the first plastic material 52 or the second plastic material 60 are processed can be designed more simply. Furthermore, in the Figure 5 illustrated multi-part design 58 simplify leakage tolerances if the insulating body 74 is designed in two parts with a first channel 44 provided on the first part 64 and a second channel 46 provided on the second part 66.

[0038] According to the illustration Figure 6 a first part 64 of the insulating body 74 can be removed in a multi-part design.

[0039] As can be seen from the perspective view of the first part 64 of the insulating body 74 according to Figure 6 As can be seen, the first channel 44 runs on the front side 42 essentially in the vertical direction 76. The first channel 44, as shown in Figure 6The cooling medium can flow through the cooling medium inlet 54 as well as inlet 56, as shown in FIG. The inlet 54 is preferably located in the area where more heat is generated, for example, if several busbars 18, 20, 22 are arranged there and these are longer.

[0040] The Figure 6 The first part 64 of the insulating body 74, shown in perspective view, accommodates the first busbar 18 or the second busbar 20, which are connected by a Figure 5 The first busbar 18 and the second busbar 20 each have the connection areas 72 at their ends. A bottom section of the first part 64 of the insulating device 40 is shown in the illustration according to Figure 6 identified with reference numeral 68. The first part 64 comprises a recess 70 so that the phase connections 16, compare illustration according to Figure 1, the electric machine 14 can be more easily connected to the connection areas 72 of the first busbar 18 and the second busbar 20.

[0041] The busbars 18, 20 and 22 are shown in the illustrations according to the Figure 4 and 5 and 6 are generally partially embedded as inserted parts in the respective insulating body 74 or in the first part 64 and its second part 66. To improve the heat transfer, a thermally conductive paste can also be provided. Furthermore, it is possible to Figure 4 , 5 and 6The illustrated busbars 18, 20, and 22 are injected into the respective plastic material 52 or 60 of the insulating body 74 or into its parts 64 and 66, respectively, in order to improve heat transfer. To save costs, it is also possible to produce the insulating body 74 of the insulating device 40 with integrated cooling medium channels 44, 46 using a pre-injection molding or to use the multi-component injection molding process. This allows the interior of the insulating body 74, for example, to be manufactured from a less expensive plastic material, and the more expensive first plastic material 52 or the second plastic material 60, which has the special reductive properties, to be used only in the areas where absolutely necessary.

[0042] The busbars 18, 20, and 22 described above can also be designed as wires, for example, as solid wires with a round or other cross-section, as twisted strands, or even as braided strands. If such geometries are selected for the busbars 18, 20, and 22, the receiving geometry in the insulating body 74 is accordingly not flat, but rather, for example, semicircular, in any case complementary to the geometry of the busbars 18, 20, and 22 that are not designed as flat. Furthermore, thermally conductive paste can be used to improve the thermal coupling of the busbars 18, 20, and 22—whether they are designed as flat wires or as wires—to the plastic material of the insulating body 74.

[0043] The invention is not limited to the embodiments described here and the aspects highlighted therein.

Claims

1. Insulating device (40) with integrated cooling-medium channels (44, 46) for dissipating heat loss of a stator of an electric machine, having an insulating body (74) with a plastic material (52, 60) in which busbars (18, 20, 22) are received, wherein the cooling-medium channels (44, 46) are integrated in the plastic material (52, 60) of the insulating body (74) and the insulating body is formed in a single-part embodiment (50) or in a multi-part embodiment (58), characterized in that the cooling-medium channels (44, 46) are injection-moulded in the region of an end face (42) of the insulating body (74).

2. Insulating device (40) according to Claim 1, characterized in that the cooling-medium channels (44, 46) extend substantially in the vertical direction (76).

3. Insulating device (40) according to Claim 1, characterized in that the first plastic material (52) is an electrically insulating plastic material optimized for the best possible heat conduction, such as Luvocom 1-8259 or Tecacomp PA 66 TC 3923.

4. Insulating device (40) according to Claim 1, characterized in that the multi-part embodiment (58) of the insulating body (74) has a first part (64) and a second part (66).

5. Insulating device (40) according to Claim 4, characterized in that the first busbar (18) and the second busbar (20) are received in the first part (64), and the second part (66) receives the third busbar (22).

6. Insulating device (40) according to Claim 4, characterized in that the first part (64) and the second part (66) are manufactured from the first plastic material (52), or the first part (64) and the second part (66) are manufactured from the second plastic material (60), or the first part (64) is manufactured from the first plastic material (52) and the second part (66) is manufactured from the second plastic material (60) and vice versa.

7. Insulating device (40) according to Claim 1, characterized in that the insulating body (74) in the single-part embodiment (50) has insulating webs (34) which separate the busbars (18, 20, 22) from one another.

8. Insulating device (40) according to Claim 1, characterized in that the parts (64, 66) of the insulating body (74) each have insulating webs (34) which insulate the busbars (18, 20, 22) with respect to one another.

9. Insulating device (40) according to Claim 1, characterized in that the insulating body (74) receives a heat-conducting paste in which the busbars (18, 20, 22) are embedded.

10. Insulating device (40) according to Claim 1, characterized in that the busbars (18, 20, 22) are injected into the plastic material (52, 60) of the insulating body (74).

11. Insulating device (40) according to Claim 1, characterized in that the insulating body (74) comprises a pre-injection-moulded part or is manufactured in a multi-component technique and the heat-conducting plastic material is only injected into the regions in which it is necessary.

12. Use of the insulating device (40) with integrated cooling-medium channels (44, 46) according to one of Claims 1 to 11 for electrical contacting and for cooling an electric machine (14) of an electric vehicle (EV), a hybrid electric vehicle (HEV) or a plug-in hybrid electric vehicle (PHEV).