Housing having housing cooling device, electric machine, method for cooling electric machine, and motor vehicle

Abstract

The invention relates to a housing (10) for an electric machine (12) of an at least partially electrically driven motor vehicle, comprising a cylindrical first housing part (14) having an outer side (24), a tubular second housing part (18) arranged on the first housing part (14) and having an inner side (26), and a housing cooling device, the housing cooling device has a first coolant connection end (20) arranged in the second housing part (18), a second coolant connection end (22) arranged at a distance from the first coolant connection end (20), and a cooling structure (28) formed on an inner side (26) and / or an outer side (24) for forming a first cooling channel (32) and a second cooling channel (34), wherein the first coolant connection end (20) and the second coolant connection end (22) are arranged offset from one another in the axial direction and in the circumferential direction of the second housing part (18), and the offset in the circumferential direction is greater than 135 DEG and less than 225 DEG, which together comprise a boundary, and the cooling structure (28) has a web (30) formed in the radial direction of the first housing part (14) and / or the second housing part (18), the webs are arranged axially offset from one another with respect to the circumferential direction in a first section (42) and run helically in a second section (44) in order to form cooling channels (32, 34).

Description

Technical Field

[0001] The invention relates to a housing for an electric motor of an at least partially electrically driven motor vehicle, the housing having two coolant connections arranged offset relative to one another both in the axial direction and in the circumferential direction, and at least two cooling channels. The subject matter of the invention is also an electric motor having a housing according to the invention. The subject matter of the invention is also a method for cooling an electric motor according to the invention. The subject matter of the invention is also a motor vehicle having an electric motor according to the invention. Background Art

[0002] Cooling devices for electric machines are known in principle. For example, DE 10 2006 044 785 A1 shows a cooling device in which a stator is surrounded by a cooling matrix, which has a cooling structure on its outer side, the cooling structure having an inlet and an outlet, wherein the cooling structure extends between the inlet and the outlet in the form of a spiral groove or in a spiral shape. In other words, only a spiral cooling channel is constructed between the inlet and the outlet. Disadvantageously, uniform cooling of the electric machine over the length of the cooling channel is impossible, because the cooling medium continuously heats up as the distance from the inlet to the outlet increases. This can be particularly problematic if the active parts of the electric machine, i.e. the rotor and the stator, are extended in the axial direction. Summary of the invention

[0003] The object of the present invention is to specify a housing for an electric machine which can have an increased cooling effect.

[0004] This object is achieved by the subject matter of the independent patent claims. Preferred improvements of the invention are the subject matter of the dependent patent claims, the following description and the drawings. In this case, each feature can be an aspect of the invention both individually and in combination, unless something to the contrary is clearly evident from the description.

[0005] In a first aspect, the present invention relates to a housing for an electric motor of an at least partially electrically driven motor vehicle, the housing comprising a first housing part having an outer side, a tubular second housing part having an inner side arranged on the first housing part, and a housing cooling device, the housing cooling device having a first coolant connection end arranged in the second housing part, a second coolant connection end arranged at a distance from the first coolant connection end, and a cooling structure constructed on the inner side and / or the outer side for constructing a first cooling channel and a second cooling channel, wherein the first coolant connection end and the second coolant connection end are arranged offset from each other in the axial direction and in the circumferential direction of the second housing part, and the offset in the circumferential direction is greater than 135° and less than 225°, and the cooling structure has a radially constructed web along the first housing part and / or the second housing part, which is arranged offset from each other in the axial direction in a first section and extends helically in a second section with respect to the circumferential direction.

[0006] In other words, according to a first aspect of the present invention, a housing for an electric motor of an at least partially electrically driven motor vehicle is provided. The housing has a first housing part, which is preferably constructed as a cylinder at least in sections. The first housing part has an outer side on a side preferably pointing radially outward. In addition, a second housing part is provided. The second housing part is constructed as a tubular and has an inner side on a side facing the first housing part. Therefore, the inner side of the second housing part faces the outer side of the first housing part. The housing further includes a housing cooling device. The housing cooling device has a first coolant connection end and a second coolant connection end arranged at a distance from the first coolant connection end in the second housing part. In addition, the housing cooling device includes a cooling structure constructed on the inner side and / or the outer side, wherein the cooling structure is set up for constructing a first cooling channel and a second cooling channel. Therefore, the first cooling channel and the second cooling channel extend between the first coolant connection end and the second coolant connection end. The first coolant connection end and the second coolant connection end are not only constructed at a distance from each other in the axial direction of the second housing part, but also offset from each other in the circumferential direction of the second housing part. Starting from the first coolant connection, the second coolant connection is arranged at an angle greater than 135° and less than 225°, preferably greater than 150° and less than 210°, particularly preferably greater than 160° and less than 200°, including the boundary. In addition, the cooling structure has a web constructed in the radial direction of the first housing part and / or the second housing part in order to construct the cooling channel. The cooling channels are arranged axially offset or parallel to each other in a first section, which relates to the circumferential direction of the first housing part and / or the second housing part. In the second section adjacent to the first section, the first cooling channel and the second cooling channel extend helically at least section by section.

[0007] If the web is constructed on the outside of the first housing part, the web is sealed relative to the inside of the second housing part. However, it is also conceivable that the web is constructed on the inside of the second housing part and is sealed relative to the outside of the first housing part. It is also conceivable that the web is constructed not only on the inside of the second housing part but also on the first side of the first housing part, so that the webs are sealed relative to each other. By constructing at least two cooling channels extending between the coolant coupling ends spaced apart from each other in the axial direction, the entire cooling channel length is distributed to at least two shorter single channels, which can lead to a smaller pressure loss of the cooling medium flowing through the cooling channel. In addition, due to the shorter length of the single channel, the cooling medium flowing through the cooling channel is heated more slowly, which can also have a positive effect on the cooling capacity. In addition, the special construction of the webs that are arranged axially offset or parallel to each other in the first section and extend helically in the second section creates the following possibility: the coolant coupling ends are arranged offset from each other not only axially but also in the circumferential direction. This can have a favorable effect on the cooling capacity because the distance between the inlet and the outlet can be increased thereby.

[0008] A preferred improvement of the present invention is that, starting from the first coolant connection, the first cooling channel and the second cooling channel extend in opposite directions. Here, the opposite directions are preferably configured in the circumferential direction of the first and / or second housing part. In other words, the first cooling channel preferably extends in a clockwise direction starting from the first coolant connection, while the second cooling channel extends in the opposite direction to the clockwise direction. Therefore, preferably, if the first coolant connection is configured as an inlet, the first cooling channel and the second cooling channel can flow evenly.

[0009] In an advantageous embodiment of the invention, it is provided that in the region of the second coolant connection, the first cooling channel and the second cooling channel meet at an angle between 0° and 45°, including the boundary. Thus, the two cooling channels can be brought together and / or divided in a simple manner in the region of the second coolant connection. It can be advantageous, but not limited to this, if the second coolant connection is designed as an outlet and the first cooling channel and the second cooling channel are brought together in terms of flow technology in this region.

[0010] According to an advantageous development of the invention, it is provided that the first coolant connection is an inlet and the second coolant connection is an outlet. It can therefore be provided that the cooling medium enters the first cooling channel and the second cooling channel via the inlet, wherein the cooling medium then flows through the two cooling channels in opposite directions. The two cooling channels are then brought together in the region of the outlet so that the cooling medium can be discharged from the housing via the outlet or the second coolant connection.

[0011] An alternative design of the present invention provides that the first coolant connection is an outlet and the second coolant connection is an inlet. It is therefore conceivable that the inlet is constructed in the region of the second coolant connection. The cooling medium flowing in via the second coolant connection is supplied to the first cooling channel and the second cooling channel, which extend parallel to each other in this region with respect to the axial length of the housing. In the region of the outlet, the cooling medium from the first cooling channel flows to the cooling medium from the second cooling channel and is discharged from the housing via the outlet.

[0012] A preferred design of the present invention is that the first cooling channel is deflected by 180° in a region. In other words, the flow direction of the first cooling channel is deflected in the region so that as long as it starts from the first coolant connection, the flow direction of the first cooling channel is the same as the flow direction of the second cooling channel due to the deflection. By deflecting the first cooling channel and gathering the first and second cooling channels in the region of the second coolant connection, it can be achieved that only the first coolant connection and the second coolant connection are required for cooling the motor. By reducing the coolant connections, leakage and costs can be reduced.

[0013] It is conceivable that the first cooling channel and / or the second cooling channel has a planar and / or flat contour between the webs.

[0014] An advantageous improvement of the present invention is that the first cooling channel and / or the second cooling channel has a groove profile at least in sections between the webs, and the groove profile extends at least in sections parallel to the webs. The surface of the first cooling channel and / or the second cooling channel can be enlarged by the groove profile, thereby improving the cooling effect. The groove profile can be constructed continuously. However, it is also conceivable that the groove profile is constructed only in sections. In this way, turbulence can preferably be generated when the cooling medium flows through the first cooling channel and / or the second cooling channel. The cooling medium is circulated in the first cooling channel and / or the second cooling channel by the turbulence, thereby improving the cooling effect.

[0015] In principle, it can be provided that the length of the first cooling channel is different from the length of the second cooling channel. In this case, however, the hydraulic resistance in the channel should then be adapted in an advantageous manner so that a uniform flow occurs through each individual channel.

[0016] Alternatively, an advantageous development of the invention provides that the length of the first cooling channel substantially corresponds to the length of the second cooling channel. Substantially means that the length of the first cooling channel is maximally + / -15% longer than the maximum length of the second cooling channel, preferably maximally + / -10% longer than the maximum length of the second cooling channel and particularly preferably maximally + / -5% longer than the maximum length of the second cooling channel.

[0017] In this regard, a preferred development of the invention consists in that the cross section of the first cooling channel is equal to the cross section of the second cooling channel.

[0018] An advantageous embodiment of the invention provides that the first housing part is a cast component. The cast component is particularly preferably cast from metal. The metal preferably comprises aluminum and / or is at least partially made of aluminum. Such a housing can be manufactured inexpensively, can have a low weight and an increased thermal conductivity in order to dissipate the heat absorbed by the housing from the active parts of the electric machine to the cooling medium.

[0019] According to a preferred design of the present invention, the second housing part is an extruded component. The extruded component is preferably made of metal. Such a second component can be manufactured simply and cheaply, thereby reducing the cost of the housing.

[0020] In a second aspect, the invention relates to an electric machine having a housing according to the invention.

[0021] Preferably, the electric machine can be designed as a separately excited and / or permanently excited electric machine.

[0022] The electric machine is particularly advantageously a component of a traction drive for a motor vehicle which is at least partially, preferably completely, electrically driven.

[0023] In a third aspect, the invention relates to a method for cooling an electric machine according to the invention, wherein a cooling medium is supplied to the first cooling channel and the second cooling channel via the first coolant connection or the second coolant connection and is discharged from the housing via the respective other coolant connection.

[0024] In this way, a method is provided in which the electric machine can have an improved cooling effect.The efficiency or performance of the electric machine can also be improved by the improved cooling effect of the electric machine.

[0025] In principle, it is conceivable that the cooling medium is oil. This is preferably provided if the cooling medium is at least partially in contact with active components of the electric machine. By using oil, corrosion of the active components can be avoided.

[0026] It is conceivable that the cooling medium is different from oil. For example, the cooling medium can be aqueous. It is conceivable that the cooling medium is a water-glycol mixture. An aqueous cooling medium is advantageous if the cooling medium does not come into direct contact with the transmission and / or active parts of the electric machine.

[0027] In a fourth aspect, the invention relates to a motor vehicle having an electric machine according to the invention.

[0028] The electric machine is set up and / or designed to at least partially electrically drive the motor vehicle. For this purpose, it is preferably provided that the electric machine is a component of a traction drive of the motor vehicle.

[0029] It should be noted that all features described above and below with respect to one aspect of the invention are equally applicable to each of the other aspects of the invention. In particular, all features of the housing may also be features of the electric machine and / or features of the method and / or features of the motor vehicle. This also applies conversely. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further features and advantages of the invention are derived from the dependent claims and the following embodiments. The embodiments should not be understood as limiting, but rather as examples. The embodiments should enable a person skilled in the art to implement the invention. The applicant reserves the right to make individual and / or multiple features of the features disclosed in the embodiments the subject of patent claims or to incorporate such features into existing patent claims. The embodiments are explained in more detail with reference to the drawings.

[0031] In said drawings:

[0032] Figure 1 A three-dimensional view showing a housing for an electric machine;

[0033] Figure 2 shows a longitudinal section through the housing of the electric machine;

[0034] Figure 3 A detailed view showing the region of the cooling structure in a first embodiment;

[0035] Figure 4 A detailed view showing the region of the cooling structure in a second embodiment;

[0036] Figure 5 a three-dimensional view showing an outer side of a first housing portion of the housing in a first perspective view;

[0037] Figure 6 A second perspective view shows a three-dimensional view of the cooling structure on the outer side. DETAILED DESCRIPTION

[0038] exist Figure 11 shows a three-dimensional view of a housing 10 for an electric machine 12. The housing 10 has a first housing part 14, which is cylindrical at least in sections. The stator 16 of the electric machine 12 is arranged in a rotationally fixed manner in the first housing part 14. The second housing part 18 is arranged on the cylindrical section of the first housing part 14. The housing 10 also has a housing cooling device. The housing cooling device has a first coolant connection 20 and a second coolant connection 22 arranged at a distance from the first coolant connection 20 in the second housing part 18.

[0039] Figure 2 The electric motor 12 is shown Figure 1 . The first housing part 14 has an outer side 24 on a side pointing radially outward. In addition, the second housing part 18 has an inner side 26 on a side pointing radially inward. The inner side 26 of the second housing part 18 faces the outer side 24 of the first housing part 14. In addition to the first coolant connection 20 and the second coolant connection 22, the housing cooling device also includes a cooling structure 28 configured on the outer side 24. The cooling structure 28 forms a first cooling channel 32 and a second cooling channel 34 separated from each other via a web 30. The first cooling channel 32 and the second cooling channel 34 extend between the first coolant connection 20 and the second coolant connection 22. The web 30 is configured on the outer side 24 and is sealed with the inner side 26 of the second housing part 18 in a fluid-tight manner.

[0040] The first coolant connection 20 and the second coolant connection 22 are not only spaced apart from one another in the axial direction of the second housing part 18, but are also offset from one another in the circumferential direction of the second housing part 18. Starting from the first coolant connection 20, the second coolant connection 22 is arranged offset relative to the first coolant connection 20 in the circumferential direction at an angle α of 170°.

[0041] At the respective axial end of the second housing part 18 , the second housing part 18 is sealed in a fluid-tight and / or medium-tight manner relative to the first housing part 14 via a sealing element 36 , preferably via an O-ring.

[0042] Figure 3 A detailed view in the region of the cooling structure 28 is shown in a first embodiment. The first cooling channel 32 and the second cooling channel 34 have a flat surface 38 between the webs 30, which extends parallel to the longitudinal axis of the housing 10. Such an embodiment with respect to the flat surface 38 can be provided over the entire length of the first cooling channel 32 and / or over the entire length of the second cooling channel 34. It is also conceivable that the flat surface 38 is only partially formed, preferably in the region of the first coolant connection 20 and / or the second coolant connection 22.

[0043] Figure 4 A detailed view in the area of ​​the cooling structure 28 in the second design is shown. In the second design, the first cooling channel 32 and the second cooling channel 34 have at least one groove profile 40 between the webs 30, which extends parallel to the webs 30 at least in sections. The groove profile 40 can increase the surface of the first cooling channel 32 and the second cooling channel 34, thereby improving the cooling effect. The groove profile can be configured continuously. However, it is also conceivable that the groove profile 40 is configured only in sections. In this way, when the cooling medium flows through the first cooling channel 32 and / or the second cooling channel 34, turbulence can preferably be generated. The cooling medium is circulated in the first cooling channel 32 and / or the second cooling channel 34 by the turbulence, thereby improving the cooling effect.

[0044] Figure 5 A three-dimensional view of the outer side 24 of the first housing part 14 is shown in a first perspective view. In the first perspective view, the first coolant connection 20 can be seen. In the present embodiment, the first coolant connection 20 is designed as an inlet. In other words, the cooling medium for cooling the housing 10 is supplied to the cooling structure 28 via the inlet.

[0045] In the first perspective view, the webs 30 for forming the first cooling channel 32 and the second cooling channel 34 are arranged parallel to one another in a first section 42 which extends in the circumferential direction of the housing 10 relative to the longitudinal direction of the housing 10 .

[0046] The cooling medium supplied to the cooling structure 28 via the first coolant connection 20 flows into a first cooling channel 32 and a second cooling channel 34 which extend from the first coolant connection 20 in the circumferential direction of the housing 10 in opposite directions.

[0047] The portion of the cooling medium that flows into the first cooling channel 32 is shown as KM1. The portion of the cooling medium that flows into the second cooling channel 34 is shown as KM2.

[0048] Figure 6 A second perspective view shows a three-dimensional representation of the cooling structure 28 on the outer side 24 of the second housing part 18. In the second perspective view, the second coolant connection 22 is shown, via which the cooling medium is discharged from the housing 10.

[0049] Furthermore, a second section 44 is shown adjacent to the first section 42, in which the first cooling channel 32 and the second cooling channel 34 extend in a helical manner. It can also be seen that the first cooling channel 32 is deflected by 180° in the region 48. In other words, the flow direction of the first cooling channel 32 is deflected in the region 48 so that the flow direction of the first cooling channel 32 is identical to the flow direction of the second cooling channel 34 due to the deflection. By deflecting the second cooling channel 34 and gathering the first cooling channel 32 and the second cooling channel 34 in the region of the second coolant connection 22, it can be achieved that in the case of two cooling channels, only the first coolant connection 20 and the second coolant connection 20 are required for cooling the electric machine 12. By reducing the number of coolant connections 20, 22 for the two cooling channels 32, 34, leakage and costs can be reduced.

[0050] By configuring at least two cooling channels 32, 34 extending between the coolant connections 20, 22 spaced apart from each other in the axial direction, the entire cooling channel length is distributed over at least two shorter single channels, which can result in a lower pressure loss of the coolant flowing through the cooling channels 32, 34. In addition, due to the shorter length of the single channels, the coolant flowing through the cooling channels 32, 34 is heated more slowly, which can also have a positive effect on the cooling capacity. In addition, the special configuration of the web 30, which is arranged axially offset from each other in the first section 42 and extends helically in the second section 44, creates the possibility of arranging the coolant connections 20, 22 offset from each other not only axially but also in the circumferential direction. This can have a favorable effect on the cooling capacity, since the distance between the inlet and the outlet can thereby be increased.

Claims

1. A housing (10) for an electric machine (12) of an at least partially electrically driven motor vehicle, the housing comprising a cylindrical first housing part (14) having an outer side (24), a tubular second housing part (18) having an inner side (26) arranged to the first housing part (14), and A housing cooling device, comprising a first coolant connection (20) arranged in the second housing part (18), a second coolant connection (22) arranged at a distance from the first coolant connection (20), and a cooling structure (28) formed on the inner side (26) and / or the outer side (24) for forming a first cooling channel (32) and a second cooling channel (34), wherein The first coolant connection end (20) and the second coolant connection end (22) are arranged offset from one another in the axial direction and in the circumferential direction of the second housing part (18), and the offset in the circumferential direction is greater than 135° and less than 225°, including the boundary, and The cooling structure (28) has webs (30) which are constructed in a radial direction of the first housing part (14) and / or the second housing part (18) in order to form cooling channels (32, 34), the webs being arranged axially offset to one another and / or parallel in a first section (42) with respect to the circumferential direction and extending helically in a second section (44).

2. The housing according to claim 1, characterized in that Starting from the first coolant connection end (20), the first cooling channel (32) and the second cooling channel (34) extend in opposite directions.

3. A housing according to any one of the preceding claims, characterised in that In the region of the second coolant connection (22), the first cooling channel (32) and the second cooling channel (34) merge at an angle between 0° and 45°, which together include the boundary.

4. A housing according to any one of the preceding claims, characterised in that The first coolant connection end (20) is an inlet, and the second coolant connection end (22) is an outlet.

5. The housing according to any one of claims 1 to 3, characterized in that The first coolant connection end (20) is an outlet, and the second coolant connection end (22) is an inlet.

6. A housing according to any one of the preceding claims, characterised in that The first cooling channel (32) is deflected by 180° in one region.

7. A housing according to any one of the preceding claims, characterised in that The first cooling channel (32) and / or the second cooling channel (34) has a groove profile (40) between the webs (30), the groove profile (40) running parallel to the webs (30) at least in sections.

8. A housing according to any one of the preceding claims, characterised in that The length of the first cooling channel (32) substantially corresponds to the length of the second cooling channel (34).

9. A housing according to any one of the preceding claims, characterised in that The first housing part (14) is a cast component.

10. A housing according to any one of the preceding claims, characterised in that The second housing portion (18) is an extruded member.

11. An electric machine (12) having a housing (10) according to any one of the preceding claims.

12. A method for cooling an electric machine (12) according to claim 11, wherein a cooling medium is supplied to the first cooling channel (32) and the second cooling channel (34) via the first coolant connection (20) or the second coolant connection (22) and is discharged from the housing (10) via the other coolant connection (20, 22).

13. A motor vehicle having an electric machine (12) according to claim 11.

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