A cooling device and an electric drive unit having a distributor ring that can be rotated by a coolant flow.

Abstract

The present invention relates to a cooling device (1) for an electric drive unit (2), the cooling device having a static feeding element (4) having a coolant feeding section (3), wherein: the coolant feeding section (3) has at least one supply channel (6) and a plurality of outlet channels (7a, 7b), the at least one supply channel extending along the longitudinal axis (5) of the feeding element (4), the plurality of outlet channels being distributed around the circumference of the feeding element (4), extending transversely to the supply channel (6), and exposed from the feeding element (4); a distributor ring (8) is held on the feeding element (4), the distributor ring being rotatable relative to the feeding element (4) and designed for coolant distribution; the distributor ring (8) is designed and adapted according to the outlet channels (7a, 7b) of the feeding element (4) such that the distributor ring (8) is directly driven in a rotational manner by the coolant flow flowing out from the outlet channels (7a, 7b) during operation. The present invention also relates to an electric drive unit (2) having the cooling device (1).

Description

Technical Field

[0001] This invention relates to a cooling device for an electric drive unit, the cooling device having a static feed element with a coolant feed section, wherein the coolant feed section has at least one supply channel and a plurality of outlet channels, the at least one supply channel extending along the longitudinal axis of the feed element, and the plurality of outlet channels arranged circumferentially distributed along the feed element, extending laterally / inclined to the supply channel and exiting from the feed element. The invention also relates to an electric drive unit having this cooling device. Background Technology

[0002] General cooling devices are well known in the prior art. For example, DE 102018 117 939A1 discloses an electric drive in which the motor is cooled via an oil passage of a transmission device. In this case, centrifugal cooling is essentially achieved, wherein the rotating component (preferably the central shaft) is provided with a through-hole through which, during operation, coolant is thrown radially outward due to centrifugal force and thus distributed to the corresponding component of the motor.

[0003] However, in this embodiment known according to the prior art, it has been found that when the oil-carrying shaft is stationary, the cooling oil cannot be further distributed. Therefore, the corresponding components are only selectively cooled—if that happens—due to the settling oil pool. Consequently, overheating may occur locally in uncooled areas. Furthermore, the design of oil distribution in the rotating shaft is relatively complex in these designs. Here, for example, the problem to be solved is: at what speed and oil pressure, how much oil flows out from which hole / through-hole? This determination makes the manufacturing of the corresponding shaft relatively complex.

[0004] There are also cooling devices in which the coolant flow is directed along specific areas of the motor. However, even when these devices are in operation, selective cooling only occurs at the previously selected location of the motor. An example of this is DE 102015 007 588A1.

[0005] Therefore, the object of the present invention is to provide a cooling device that is as simple as possible and can achieve efficient cooling regardless of the speed of the rotary drive shaft. Summary of the Invention

[0006] According to the invention, this objective is achieved by housing a distributor ring on a feeding element, the distributor ring being rotatable relative to the feeding element and designed for coolant distribution, wherein the distributor ring is designed and matched according to the outlet channel of the feeding element such that the distributor ring is directly rotatably driven by the coolant flow flowing out of the outlet channel during operation.

[0007] By providing a rotatable distributor ring on the feed element, a cooling device is provided that can operate independently of other components of the drivetrain that rotate during operation, thus effectively cooling the drive unit even when stationary. By rotating the distributor ring accordingly, coolant is distributed over a large area to cool the relevant components as effectively as possible. Furthermore, the design of the cooling device remains as simple as possible.

[0008] Other advantageous embodiments are claimed by the dependent claims and are described in more detail below.

[0009] Therefore, it is also advantageous that the distributor ring is designed to deflect the coolant (preferably oil) flowing out of the outlet channel during operation, thereby causing the coolant to be discharged from the distributor ring toward the environment in the radial and / or axial direction (longitudinal axis). Thus, the coolant is distributed over a large area during operation.

[0010] Furthermore, it has proven advantageous that the feed element and / or distributor ring is annular. Therefore, the cooling system can be integrated into the drive unit in the most space-efficient manner.

[0011] Furthermore, it is advantageous that the feeding element is provided directly from the area fixed to the housing. This further simplifies the construction.

[0012] For designs with simple bearing and distributor ring configurations, it has proven advantageous to rotatably mount the distributor ring on the axial end of the feed element. More preferably, the distributor ring is mounted on the axially projecting (preferably also annular) support area of ​​the feed element. In this way, the installation space requirement is further reduced.

[0013] When the distributor ring is supported axially relative to the feed element, the distributor ring is also supported axially in the simplest possible way.

[0014] For efficient coolant distribution, it has also been found advantageous that the distributor ring has a first wall region and / or a second wall region, the first wall region being radially arranged outside the feed element relative to the longitudinal axis of the feed element, and the second wall region being radially arranged inside the feed element.

[0015] If the first wall region and / or the second wall region have multiple radial through holes distributed along the circumferential direction, then effective cooling of the corresponding component is achieved at both the radially inner and radially outer sides of the distributor ring.

[0016] For robust design of the distributor ring, it is also advantageous that the distributor ring has a substantially U-shaped cross-section.

[0017] If the outlet channel of the feed element is positioned circumferentially (inclined), the distributor ring can be driven during operation in the simplest possible manner. Therefore, the coolant is discharged radially and obliquely circumferentially toward the inside or outside of the feed element, and encounters corresponding opposing regions of the distributor ring at a distance from the feed element. These opposing regions are preferably implemented as corresponding guide vanes or recesses on / inside the distributor ring. Thus, the structure of the distributor ring is achieved as simply as possible.

[0018] Furthermore, the present invention relates to an electric drive unit for a hybrid or pure electric powertrain of a motor vehicle, the electric drive unit having an electric motor and a cooling device according to the invention according to at least one of the embodiments described above, wherein the cooling device is arranged such that a distributor ring is radially inside or radially outside at least one component of the electric motor.

[0019] In other words, fluid cooling, preferably driven by fluid pressure, is achieved through a rotating ring (distributor ring). The pressure of the cooling fluid is used to rotate other components in the form of a distributor ring, distributing the coolant over a large surface area around the fluid outlet point. More specifically, the ring (distributor ring) is fitted onto a fluid guiding component to distribute the cooling fluid over corresponding areas. Cooling fluid is injected into the ring at specific points, causing the ring to rotate due to eccentric injection and corresponding contours on the ring. Holes are also formed in the ring through which coolant can be discharged to the outside or inside. When the ring is configured to rotate under the pressure of the cooling fluid, the holes in the ring also rotate, distributing the coolant over a large area. This allows the coolant to be distributed throughout the entire ring, where the ring is driven solely by the pressure of the coolant fluid. Attached Figure Description

[0020] The invention will now be described in more detail with reference to the accompanying drawings.

[0021] In the attached diagram:

[0022] Figure 1 A longitudinal cross-sectional schematic diagram of a cooling device according to the invention, based on a preferred exemplary embodiment, is shown, as has been used in the partially shown electric drive unit, wherein the structure of the cooling device is shown in detail at the portions of the feeding element and the distributor ring mounted thereon.

[0023] Figure 2 It shows Figure 1 The longitudinal section of the cooling device used, wherein the flow of coolant during operation is shown by flow arrows,

[0024] Figure 3 It shows that according to Figure 1 and Figure 2A cross-sectional view of the circumferential region of the cooling device, wherein the cross-section is chosen such that both two through-holes passing radially through the distributor ring and multiple outlet channels formed in the feed element can be seen.

[0025] Figure 4 It shows something similar to Figure 3 A cross-sectional view of the cooling device, wherein the flow of coolant from the outlet channel during operation is indicated by flow arrows, and

[0026] Figure 5 It shows something similar to Figure 3 and Figure 4 A cross-sectional view of the cooling device, in which multiple recesses formed in the distributor ring can also be seen.

[0027] The accompanying drawings are merely illustrative in nature and are therefore intended only for understanding the purpose of this invention. The same elements are given the same reference numerals. Detailed Implementation

[0028] Figure 1 The basic structure of an electric drive unit 2 with a cooling device 1 according to the present invention is shown. The electric drive unit 2 is typically used during operation in the transmission system of a motor vehicle (not shown in detail for clarity). This motor vehicle transmission system can be implemented purely electrically or in a hybrid manner. The motor 14 provided in the electric drive unit 2 drives the motor vehicle in the corresponding electric or hybrid operation mode. Figure 1 The stator 15 and rotor 16 of the motor 14 are shown in a highly simplified manner.

[0029] According to the invention, a cooling device 1 is housed within a space in the electric drive unit 2. During operation, the cooling device 1 cools the components of the motor 14, preferably the stator 15 and / or the rotor 16, by generating a coolant flow. The cooling device 1 is housed within the housing of the motor 14 (not shown in more detail for clarity). For this purpose, the cooling device 1 has a feeding element 4, which is statically and therefore fixedly attached to or formed directly from the housing of the motor 14.

[0030] like Figure 1 As can be clearly seen, the feed element 4 is essentially annular. The feed element 4 extends annularly around the central longitudinal axis 5. The axial, radial, and circumferential directions used here are referenced to this longitudinal axis 5. Therefore, the axial direction is understood as the direction along the longitudinal axis 5, the radial direction is understood as the direction perpendicular to the longitudinal axis 5, and the circumferential direction is understood as the direction along a circular line concentric with the longitudinal axis 5.

[0031] As in Figure 1 As can be seen in more detail, the feeding element 4 has a coolant feeding section 3. Specifically, in Figure 1 The feed channel 6 extending axially from the feed element 4 can be seen. In this way, multiple feed channels 6 are distributed circumferentially within the feed element 4. The corresponding feed channels 6 transition towards the free end 9 of the feed element 4 to two outlet channels 7a and 7b. The first outlet channel 7a extends radially outward from the feed channel 6 and protrudes from the feed element 4 toward the radially outer side 27. The second outlet channel 7b extends radially inward from the feed channel 6 and protrudes from the feed element 4 toward the radially inner side 28. The feed channels 6 are essentially designed as blind holes and thus terminate in front of the axial end face 20 of the feed element 4.

[0032] The annular distributor ring 8 is also rotatably housed on the feed element 4. The distributor ring 8 is arranged centered on the longitudinal axis 5. The distributor ring 8 is rotatably mounted / supported on the feed element 4 about the longitudinal axis 5 (the axis of rotation). In addition, the distributor ring 8 is supported axially relative to the feed element 4.

[0033] As in Figure 1 and Figure 2 As can be seen in more detail, the feed element 4 has an axially extending portion in the form of a bearing region 10 for rotatably supporting the dispenser ring 8. In this embodiment, the bearing region 10 is implemented in the form of a ring and thus extends completely around the circumference of the feed element 4. The radially extending / axially arranged sidewall 21 of the dispenser ring 8 adjacent to the feed element 4 has a recess 22, which also extends circumferentially and opens axially toward the feed element 4, and slidably receives the bearing region 10. The recess 22 is implemented as a groove. Therefore, when the dispenser ring 8 rotates relative to the feed element 4, the bearing region 10 slides out of the recess 22.

[0034] A locking pin 23 / locking bolt is provided to axially lock the distributor ring 8. On one hand, the locking pin 23 (more preferably multiple times in the circumferential direction) is anchored in the distributor ring 8, and on the other hand, it is rotatably / slidably mounted in an annular circumferential recess 24 in the form of a groove 24. The locking pin 23 is radially oriented and is therefore fixed / supported relative to the feed element 4 by the side of the recess 24 in the axial direction.

[0035] In addition, such as combining Figures 3 to 5 It can be seen particularly well that the distributor ring 8 is designed such that the coolant flow (as indicated by the corresponding arrow 18) flowing out of the outlet channels 7a, 7b during operation impacts the distributor ring 8 in such a way that the distributor ring 8 is directly driven to rotate therefrom.

[0036] Therefore, the distributor ring 8 is provided with Figure 3 and Figure 4The fluid deflection section, omitted for clear reasons, ensures that... Figure 4 The coolant flow 18 discharged radially outward and radially inward from the feed element 4 causes the distributor ring 8 to rotate. For this purpose, in Figure 5 The following is illustrated in more detail by way of example: the fluid deflection section is preferably designed as a plurality of recesses 17 distributed in the circumferential direction, the plurality of recesses being formed on the radial region of the distributor ring 8 facing the feed element 4. When the coolant flow 18 impinges on the peripheral side of the recesses 17, the impulse of the coolant flow 18 is transmitted to the distributor ring 8, and the distributor ring is rotated (according to...). Figure 3 (Rotation direction arrow 19 in the image).

[0037] For example Figure 4 As shown, the outlet channels 7a and 7b are positioned circumferentially and therefore at an angle when viewed radially to transfer impulse to the distributor ring 8 circumferentially. It should be noted in particular that the distributor ring 8 can also be implemented in other versions in other ways, especially with respect to the fluid deflection section, which is more preferably also implemented as an integral or separately attached conveyor blade.

[0038] like Figure 1 and Figure 2 As can be seen, the distributor ring 8 has a substantially U-shaped cross-section. The distributor ring 8 has a first wall region 11 in the form of an outer wall region and a second wall region 12 in the form of an inner wall region. The two wall regions 11, 12 are offset from each other in the radial direction and are connected to each other via a side wall 21. The first wall region 11 is arranged radially outside the radially outer side 27 of the feed element 4, while the second wall region 12 is arranged radially inside the radially inner side 28 of the feed element 4. The two wall regions 11 cover the feed element 4, particularly in the sections having outlet channels 7a, 7b.

[0039] Wall regions 11, 12 and sidewall 21 form a distribution space 26 with the feed element 4, in which coolant flowing out of the outlet opening 7 during operation is collected, distributed and transferred. Each of wall regions 11, 12 has a recess 17 on its radial side facing the feed element 4. These recesses 17 are axially positioned at the level of the outlet channels 7a, 7b in a generally normal manner.

[0040] The distributor ring 8 has multiple radially distributed through holes 13 on both its radially inner and radially outer sides, that is, on the sides of its first wall region 11 and its second wall region 12. For example... Figure 2As indicated, these through-holes 13 discharge coolant, thereby generating a (discharged) cooling flow 25 that flows through the electrically driven unit 2. The through-holes are arranged to be axially offset relative to the outlet channels 7a, 7b.

[0041] In other words, according to the invention, fluid pressure is used to rotate another component (distributor ring 8) to distribute cooling fluid over a large area around the fluid outlet point. This concept is achieved by applying ring 8 to the fluid-carrying component 4, which aims to distribute cooling fluid over a large area. Cooling fluid is introduced into ring 8 at certain points, and the ring 8 is designed to rotate through eccentric introduction and corresponding contour 17. Holes 13 are formed in ring 8, allowing cooling fluid to be thrown outwards or both outwards and inwards. Because ring 8 is configured to rotate by fluid pressure, these holes 13 in ring 8 also rotate, thus achieving a planar distribution of cooling fluid. Therefore, the possibility of distributing cooling fluid over a wide area around ring 8, where ring 8 is driven solely by fluid pressure, is created. The design of how much fluid this component distributes is also much simpler than known centrifugal cooling systems because there is no influence from the speed of the transmission, and the design of how much fluid reaches where can be statically implemented within the system.

[0042] like Figure 1 As can be seen, fluid is supplied via static component 4. Component 4 should be a rotationally symmetrical ring. Guide ring 10 is located at end 9 of static component 4. Distributor ring 8 is placed on this ring 10, thus allowing the distributor ring to rotate freely. Distributor ring 8 is secured to prevent axial movement by bolts 23, etc., which are fitted into holes in the distributor 8 and protrude into grooves 24 in the static component 4.

[0043] exist Figure 2 As can be seen, the fluid is introduced into the distributor ring 8 and guided to the point to be cooled via the circumferentially distributed holes 13 around the ring 8. The holes 7a and 7b on the static component are offset relative to the axis of rotation 5 to accelerate the distributor ring 8.

[0044] As in Figures 3 to 5 As can be seen, the distributor ring 8 is accelerated through the holes 7a and 7b from the static component 4, thus the fluid is evenly distributed on the circumference. Depending on the pressure, the distributor ring 8 may be provided with a profile 17, etc.; for example, to create a better contact surface for the fluid.

[0045] List of reference numerals

[0046] 1. Cooling device

[0047] 2 Electric drive units

[0048] 3. Coolant Feeding

[0049] 4 Feeding elements

[0050] 5. Longitudinal axis

[0051] 6. Supply Channels

[0052] 7. Exit opening

[0053] 7a First Exit Passage

[0054] 7b Second Exit Passage

[0055] 8 Distributor ring

[0056] 9 ends

[0057] 10 Bearing Area

[0058] 11 First Wall Area

[0059] 12 Second Wall Area

[0060] 13 Through holes

[0061] 14 Motors

[0062] 15 stators

[0063] 16 rotors

[0064] 17 recess

[0065] 18 Flowing arrows

[0066] 19. Rotation direction arrow

[0067] 20 end face

[0068] 21 Sidewall

[0069] 22. Depression

[0070] 23 Locking pins

[0071] 24 recess

[0072] 25 Cooling flow

[0073] 26 Distribution Space

[0074] 27 Outer side

[0075] 28 Inner side

Claims

1. Cooling device (1) for an electric drive unit (2), having a static feed element (4) which is fixedly attached to the housing of an electric machine (14) in the electric drive unit (2) or is formed directly by the housing, the static feed element having a coolant feed (3), wherein: The coolant feed (3) has at least one supply channel (6) which extends along a longitudinal axis (5) of the feed element (4) and a plurality of outlet channels (7a, 7b) which are distributed around a circumference of the feed element (4), extend transversely to the supply channel (6) and are exposed from the feed element (4), characterized in that a distributor ring (8) is held on the feed element (4), which can be rotated relative to the feed element (4) and is designed for coolant distribution, wherein the distributor ring (8) is designed and adapted to the outlet channels (7a, 7b) of the feed element (4) such that the distributor ring (8) is directly driven in rotation by the coolant flow which flows from the outlet channels (7a, 7b) during operation.

2. Cooling device (1) according to claim 1, characterized in that The distributor ring (8) is designed such that it deflects the coolant flowing from the outlet channels (7a, 7b) during operation, so that the coolant is discharged from the distributor ring (8) in a radial and / or axial direction towards the environment.

3. Cooling device (1) according to claim 1 or 2, characterized in that The feed element (4) and / or the distributor ring (8) is annular.

4. Cooling device (1) according to one of claims 1 to 3, characterized in that The distributor ring (8) is rotatably mounted on an axial end (9) of the feed element (4).

5. Cooling device (1) according to one of claims 1 to 4, characterized in that The distributor ring (8) is supported in an axial direction relative to the feed element (4).

6. Cooling device (1) according to one of claims 1 to 5, characterized in that The distributor ring (8) has a first wall region (11) which is arranged radially outside the feed element (4) relative to a longitudinal axis (5) of the feed element (4) and / or a second wall region (12) which is arranged radially inside the feed element (4).

7. Cooling device (1) according to claim 6, characterized in that The first wall region (11) and / or the second wall region (12) has a plurality of radial through-holes (13) which are distributed in a circumferential direction.

8. Cooling device (1 ) according to one of claims 1 to 7, characterized in that The distributor ring (8) has a U-shaped cross-section.

9. Cooling device (1 ) according to one of claims 1 to 8, characterized in that The outlet channels (7a, 7b) of the feed element (4) are arranged in the circumferential direction.

10. An electric drive unit (2) for a hybrid or purely electric drive train of a motor vehicle, having an electric machine (14) and a cooling device (1) according to one of claims 1 to 9, wherein The cooling device (1) is arranged at least such that the distributor ring (8) is radially inside at least one component (15, 16) of the electric machine (14) or radially outside the at least one component of the electric machine (14).

Images