Cooling-Element Part for a Cooling Element of an Electrical Drive Unit with Droplet-Shaped Pins, Cooling Element, Electrical Drive Unit and Motor Vehicle

Abstract

The invention relates to a cooling-element part for a cooling element for cooling at least one component of an electrical drive unit of a motor vehicle and can be joined together with a further cooling-element part to form at least one cooling-fluid-carrying cooling duct to the cooling element, and which has a cooling structure configured to increase a flow resistance for the cooling fluid by producing turbulences in the flow having pins that extend at least partially over a height of the cooling duct, wherein the pins are formed as droplet-shaped having a width that decreases in the direction of the flow of the cooling fluid.

Claims

1. A cooling-element part for a cooling element for cooling at least one component of an electrical drive unit of a motor vehicle, the cooling-element part configured to: join together with a further cooling-element part to form at least one cooling-fluid-carrying cooling duct to the cooling element; wherein the cooling-element part comprises: a cooling structure configured to increase a flow resistance for cooling fluid by producing turbulences in a flow of the cooling fluid, the cooling structure comprising a plurality of pins that extend at least partially over a height of the cooling duct, wherein the pins are droplet-shaped having a width that decreases in a direction of the flow of the cooling fluid.

2. The cooling-element part according to claim 1, wherein at least two pins of the plurality of pins are arranged next to one another in a row transversely to the direction of the flow, and at least two rows with pins are arranged along the direction of the flow, and the pins of two adjacent rows of the at least two rows along the direction of the flow are arranged offset in relation to one another.

3. The cooling-element part according to claim 1, wherein the cooling structure has webs that at least partially extend over a length of the at least one cooling duct along the direction of the flow and are wave-shaped.

4. The cooling-element part according to claim 1, wherein the cooling structure comprises further pins configured to homogenize the cooling fluid flow on at least one end portion of the cooling-element part that forms at least one of an inflow region or an outflow region of the cooling element for the cooling fluid.

5. The cooling-element part according to claim 4, wherein the further pins have an elliptical form, wherein a main axis of a first set of the further pins are oriented transversely to the direction of the flow, and a main axis of a second set of the further pins are oriented along the direction of the flow.

6. The cooling-element part according to claim 1, comprising a hollow-cylindrical form, forming a hollow-cylindrical cooling element for cooling a stator of an electric drive machine.

7. The cooling-element part according to claim 1, wherein the droplet-shaped pins comprise roll-shaped pins or cast pins.

8. A cooling element, comprising: at least one cooling-element part according to claim 1, wherein the at least one cooling-element part is joined together with the further cooling-element part to form the at least one cooling duct, and wherein the cooling element is for an electric drive unit for cooling at least one component of the drive unit.

9. A drive unit for an electrically drivable motor vehicle having at least one component, the drive unit comprising: a cooling element according to claim 8, wherein the drive unit comprises at least one of an electric machine, a high-voltage battery, or an inverter.

10. A motor vehicle comprising: at least one drive unit according to claim 9.

11. The cooling-element part according to claim 2, wherein the cooling structure has webs that at least partially extend over a length of the at least one cooling duct along the direction of the flow and are wave-shaped.

12. The cooling-element part according to claim 2, wherein the cooling structure comprises further pins configured to homogenize the cooling fluid flow on at least one end portion of the cooling-element part that forms at least one of an inflow region or an outflow region of the cooling element for the cooling fluid.

13. The cooling-element part according to claim 12, wherein the further pins have an elliptical form, wherein a main axis of a first set of the further pins are oriented transversely to the direction of the flow, and a main axis of a second set of the further pins are oriented along the direction of the flow.

14. The cooling-element part according to claim 3, wherein the cooling structure comprises further pins configured to homogenize the cooling fluid flow on at least one end portion of the cooling-element part that forms at least one of an inflow region or an outflow region of the cooling element for the cooling fluid.

15. The cooling-element part according to claim 14, wherein the further pins have an elliptical form, wherein a main axis of a first set of the further pins are oriented transversely to the direction of the flow, and a main axis of a second set of the further pins are oriented along the direction of the flow.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 shows a schematic representation of a cooling-element part for a cooling element for a component of an electrical drive unit from a first perspective;

[0026] FIG. 2 shows an enlarged detail of the cooling-element part according to FIG. 1;

[0027] FIG. 3 shows a schematic representation of the cooling-element part from a second perspective; and

[0028] FIG. 4 shows a schematic representation of the cooling-element part from a third perspective.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] In the figures, elements that are the same or functionally the same are provided with the same designations.

[0030] FIG. 1, FIG. 2, FIG. 3 and FIG. 4 show different perspective representations of a cooling-element part 1, which forms with a further cooling-element part a double-walled, multi-part cooling element for a component of an electrical drive unit of an electrically drivable motor vehicle. The cooling element forms here a multi-part, jacket-like cooling housing of the component. The cooling element serves here for cooling a component in the form of a cylindrical stator of an electric drive machine of the motor vehicle. The cooling element is therefore of a hollow-cylindrical form here, so that the cooling-element part 1 and the further cooling-element part not shown here are likewise of a hollow-cylindrical or sleeve-shaped form. The cooling element can guide a cooling fluid along a direction of flow S, which here is oriented along an axial direction A of the hollow-cylindrical cooling-element part 1. For this purpose, an intermediate space formed by the cooling-element part 1 and the further cooling-element part forms at least one flow space or at least one cooling duct for the cooling fluid. The cooling-element part 1 shown here is an inner housing, and consequently forms an inner wall, facing the component, of the cooling housing. It may however also be that the cooling-element part 1 is an outer housing and forms an outer wall, facing the surrounding area.

[0031] The cooling-element part 1 is structured and as a result has a cooling structure 2, which is designed to increase a flow resistance for the cooling fluid in the flow space by producing turbulences in the flow. The cooling structure 2 is in this case formed on a surface of the cooling-element part 1 that is assigned to the further cooling-element part. The further cooling-element part may be of an unstructured form and have a smooth surface. The cooling structure 2 may for example be stamped into the sheet-like cooling-element part 1. The cooling structure 2 has pins 3, which here are oriented in a radial direction R and, in the joined-together state of the cooling element, extend from the cooling-element part 1 to the further cooling-element part over an overall height of the cooling duct. The pins 3 have in this case a droplet shape, so that a width b of the pins 3 decreases downstream, that is to say in the direction of flow S. These droplet-shaped pins 3 have the effect that the cooling structure 2 has a reduced boundary-layer separation in comparison with round pins, and as a result a low pressure loss and a high convective heat transport.

[0032] The pins 3 are in this case arranged here in pins zones P. Each pin zone P has at least two rows X1, X2, with in each case at least two pins 3. The pins 3 are arranged next to one another transversely to the direction of flow, here along the circumferential direction U, the rows X1, X2 being alternately arranged in the direction of flow S. In this case, the pins 3 of the rows X1 are arranged offset with respect to the pins 3 of the rows X2. The offset arrangement of the droplet-shaped pins 3 has the advantage as compared with an in-line arrangement of the pins 3, in which the pins 3 are arranged in parallel-running columns or lines oriented along the direction of flow S, that as a result the buildup of a thermal boundary layer can be disrupted, and consequently a higher convective heat transfer at a wall of the housing can be achieved. The thinner the thermal boundary layer, the higher the convective heat transfer. The cooling structure 2 also preferably has wave-shaped webs 4, which extend along the direction of flow S. In this case, a web 4 is arranged in each case between two pin zones P. The webs 4 provide further turbulences in the flow and increased stiffness of the cooling element.

[0033] The cooling-element part 1 also has two end portions E1, E2, a first end portion E1 forming an inflow region for the cooling fluid into the cooling element and a second end portion E2 forming an outflow region for the cooling fluid out of the cooling element. Here, further pins 5a, 5b, which have for example an elliptical shape and are designed for homogenizing the cooling fluid flow, are arranged in the second end portion E2, forming the outflow region. First of the further pins 5a are in this case arranged in such a way that a main axis of the, for example elliptical, pins 5a is oriented along the circumferential direction U, and second of the further pins 5b are in this case arranged in such a way that a main axis of the, for example elliptical, pins 5b is oriented along the direction of flow S. The first further pins 5a are in this case arranged in a number of rows, the pins 5a of two successive rows likewise being arranged offset in relation to one another.

[0034] Furthermore, the cooling-element part 1 has here a collar 6 on one end portion E1 and a constriction 7 on the axially opposite end portion E2. The collar 6 and the constriction 7 serve for mechanically connecting, for example welding, to the further cooling-element part to form the cooling element.

[0035] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.