DE102020108138A1 - Busbar for combined power and coolant line; as well as drive unit - Google Patents

Abstract

The invention relates to a busbar (1) for the electrical connection of a power electronics unit (2) to an electrical machine (3), with several line sections (5, 6, 7) which are decoupled from one another via an insulation (4) and are made of an electrically conductive material ), each line section (5, 6, 7) having a connection region (9a, 9b) to a first end (8a) and to its second end (8b) opposite the first end (8a), and wherein the line sections ( 5, 6, 7), with the formation of a cooling channel (10), are continuously hollow. The invention also relates to a drive unit (15) with this busbar (1).

Description

The invention relates to a busbar for the electrical connection of a power electronics unit to an electrical machine, with several line sections (electrically) decoupled from one another via insulation and made of an electrically conductive material, each line section to a first end and to one, the first end opposite, second end has a connection area. The busbar is therefore also referred to as a current busbar or busbar. In addition, the invention relates to an (electric) drive unit for a purely electrically driven or hybrid motor vehicle, the electrical machine of which is coupled to a power electronics unit via the busbar.

Generic drive units and busbars are already sufficiently known from the prior art. In this context, for example DE 10 2016 219 213 A1 a condenser unit in which two support elements are implemented directly as busbars and in one end section of which cooling medium flows around them.

In these designs known from the prior art, however, it has been found that the line sections of the busbars still have to be dimensioned relatively large so that the currents to be transmitted during operation do not cause any heat damage. The cross-section must be selected to be large enough so that little heat is generated and this can be dissipated via heat conduction.

It is therefore the object of the present invention to provide a busbar that is cooled more efficiently and consequently more powerful.

This is achieved according to the invention in that the line sections, with the (direct) formation of a cooling channel, are continuously hollow.

As a result of this integration of the cooling channel directly into the line section used for power transmission, the line sections are effectively cooled over their entire length.

Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

It has been found to be particularly practicable if the line sections are formed at least partially / along their length in sections from a tube. As a result, the line sections can be produced as simply as possible.

In this regard, it is particularly advantageous if each line section is also formed by a bent tube.

Furthermore, it is expedient if the line sections are arranged next to one another in a plane of extent. As a result, the busbar can typically be arranged in a manner that is as space-saving as possible.

Furthermore, it is expedient if electrical contacting and / or sealing of the cooling channel on an outside of the line section is implemented at the connection areas of the line sections.

Furthermore, the invention relates to a drive unit for a purely electrically or hybrid-powered motor vehicle, with an electrical machine, a power electronics unit and a busbar that electrically connects the power electronics unit to the electrical machine and is designed according to at least one of the embodiments described above, wherein each line section (the Busbar) is connected to a coil sub-unit of the electrical machine.

In this context, it is also advantageous if the line sections directly form part of a hydraulic circuit flowing through the power electronics unit and / or the electrical machine (at least in sections). As a result, the line sections also serve as a coupling element for feeding coolant into the electrical machine or into the power electronics unit.

In other words, according to the invention, an e-axle with a combined busbar for electricity and cooling medium is implemented between an inverter and an electric motor.

The invention will now be explained in more detail below with reference to figures.

• 1 eine Schnittansicht einer erfindungsgemäßen Sammelschiene nach einem bevorzugten Ausführungsbeispiel, wobei die Schnittebene derart gewählt ist, dass drei in der Sammelschiene vorhandene Leitungsabschnitte in ihrer Längsrichtung geschnitten sind,
• 2 eine perspektivische Darstellung einer Anordnung der drei in 1 eingesetzten Leitungsabschnitte, sowie
• 3 eine Draufsicht auf eine elektrische Antriebseinheit, die mit einer Sammelschiene nach 1 ausgestattet ist.

Show it:

• 1 a sectional view of a busbar according to the invention according to a preferred embodiment, the cutting plane being selected such that three line sections present in the busbar are cut in their longitudinal direction,
• 2 a perspective view of an arrangement of the three in 1 used line sections, as well as
• 3 a plan view of an electric drive unit with a busbar according to 1 Is provided.

The figures are merely of a schematic nature and are therefore used exclusively for understanding the invention. The same elements are provided with the same reference symbols.

A busbar according to the invention 1 as described below in connection with the 1 and 2 is described in detail is according to 3 preferably between an electric machine 3 and a power electronics unit 2 in an electric drive unit 15th used. The electric drive unit 1 is designed as an electric axle drive unit / E-axle. The drive unit 15th thus has at least one schematically illustrated electrical machine 3 and one in the 3 Undetectable gearbox that has an output (torque output) of the electrical machine 3 connected to. The transmission is further coupled to a wheel of the motor vehicle.

The power electronics unit 2 is typically a unit that includes an inverter. The power electronics unit 2 is used to control the different in 3 indicated coil subunits 16a , 16b , 16c used to provide them with the required electrical power. The coupling of the power electronics unit 2 with the electric machine 3 takes place via the with 1 busbar shown in more detail 1 .

The busbar 1 forms a combination of an electrical transmission unit and a hydraulic transmission unit. In this version, the busbar has 1 three line sections 5 , 6th , 7th on, which is between a first connection area 9a on the part of the power electronics unit 2 and a second connection area 9b on the part of the electrical machine 3 extend. The line sections 5 , 6th , 7th each consist of an electrically conductive material, e.g. a copper or aluminum alloy.

Each line section is according to the invention 5 , 6th , 7th , with the formation of a cooling channel 10 , continuously hollow. Every line section 5 , 6th , 7th thus forms a coolant passage as part of a hydraulic circuit 14th , through which coolant passage a preferably on the part of the power electronics unit 2 inflowing cooling medium into the interior of the electrical machine 3 , preferably in the direction of the coil sub-units 16a , 16b , 16c , is forwarded.

In this version there are a total of three line sections 5 , 6th , 7th present in a common extension plane 12th lie. The line sections 5 , 6th , 7th have an arcuate extension, the arcs of the various line sections 5 , 6th , 7th differ from each other in their radii.

The line sections 5 , 6th , 7th are made from a (one-piece) tube 11 formed what pipe 11 is used to transmit electrical power. The pipe 11 directly forms the arcuate part of the respective line section 5 , 6th , 7th the end. A sole consideration of the line sections 5 , 6th , 7th forming pipes 11 is with 2 made clear. Accordingly, the pipe points 11 of the first line section 5 an arc with a first radius, the pipe 11 of the second line section 6th an elbow with a second radius selected greater than the first radius and the pipe 11 of the third line section 7th an arc with a selected, larger than the second radius, third radius.

On the part of their ends 8a , 8b are the line sections 5 , 6th , 7th each with the first and the second connection area 9a , 9b Mistake. In this context, it should also be noted that the radial outside 13th of the pipe 11 of each line section 5 , 6th , 7th for further contacting of the components of the power electronics unit 2 or the electrical machine 3 serves. At the same time is the radial outside 13th implemented as a sealing surface and in contact with a seal 17th (Sealing ring). This is the inside of the tube 11 at the interfaces to the electrical machine 3 and the power electronics unit 2 sealed against the environment.

In other words, a basic idea of the inventive solution results in the design of the busbar / busbar 1 as a pipe 5 , 6th , 7th ; 11 through which the cooling medium can be passed. It is particularly advantageous if this coolant is used in addition to cooling the busbar 1 also for the electric machine 3 and / or power electronics 2 is being used. In this way, the effort required for separate cooling can be reduced or saved entirely. The installation space for the separate coolant connection can also be saved. It also becomes the bus bar 1 more effectively cooled, which can allow a higher power density. Especially with oil-flooded inverters 2 and engine 3 this design is advantageous because there is no additional sealing effort, since the circuits are interrelated. The contacting is preferably carried out in such a way that the fluid for cooling comes directly from the power electronics 2 into the electric machine 3 can be promoted. The electrical contact can be made jointly with the seal 17th over the outer contour 13th / the outer diameter of the pipe 5 , 6th , 7th take place.

List of reference symbols

1

Busbar

2

Power electronics unit

3rd

electric machine

4th

insulation

5

first line section

6th

second line section

7th

third line section

8a

first end

8b

second end

9a

first connection area

9b

second connection area

10

Cooling duct

11

pipe

12th

Extension plane

13th

Outside

14th

Hydraulic circuit

15th

Drive unit

16a

first coil sub-unit

16b

second coil sub-unit

16c

third coil sub-unit

17th

poetry

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

• DE 102016219213 A1 [0002]

Claims (7)

Busbar (1) for the electrical connection of a power electronics unit (2) to an electrical machine (3), with several line sections (5, 6, 7) which are decoupled from one another via an insulation (4) and are made of an electrically conductive material, each Line section (5, 6, 7) has a connection area (9a, 9b) to a first end (8a) and to its second end (8b) opposite the first end (8a), characterized in that the line sections (5, 6, 7), with the formation of a cooling channel (10), are continuously hollow. Busbar (1) Claim 1 , characterized in that the line sections (5, 6, 7) are at least partially formed from a tube (11). Busbar (1) Claim 1 or 2 , characterized in that the tube (11) is bent. Busbar (1) after one of the Claims 1 until 3 , characterized in that the line sections (5, 6, 7) are arranged next to one another in a plane of extension (12). Busbar (1) after one of the Claims 1 until 4th , characterized in that at the connection areas (9a, 9b) of the line sections (5, 6, 7) an electrical contact and / or a seal of the cooling channel (10) on an outside (13) of the line section (5, 6, 7) is implemented. Drive unit (15) for a purely electrically or hybrid-powered motor vehicle, with an electric machine (3), a power electronics unit (2) and a busbar (1) electrically connecting the power electronics unit (2) to the electric machine (3) according to one of the Claims 1 until 5 , each line section (5, 6, 7) being connected to a coil sub-unit (16a, 16b, 16c) of the electrical machine (3). Drive unit (15) Claim 6 , characterized in that the line sections (5, 6, 7) directly form part of a hydraulic circuit (14) flowing through the power electronics unit (2) and / or the electrical machine (3).

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