DE102013215615A1 - Assembly for a drive train of a motor vehicle - Google Patents

Abstract

A construction unit (10) for a drive train of a motor vehicle is proposed which has an electrical machine (14) arranged in a fluid space (12) and a fluid-carrying drive train component (40). In this case, the electric machine (14) comprises a stator (18) and a rotor (16). The drivetrain component (40) comprises a fluid which can be acted upon by an operating pressure and a fluid connection (58). Furthermore, the rotor (16) and / or the stator (18) has at least one respective fluid channel (54; 78) for cooling the electric machine (14) which is in fluid communication with the fluid connection (58) of the drive train component (40).

Description

The application relates to a structural unit for a drive train of a motor vehicle, in particular a structural unit consisting of an electric machine and a drive train component in operative connection therewith.

As is known, electrical machines generate heat losses during operation which can considerably influence the efficiency. To ensure the operation of electrical machines and maximizing the efficiency of effective cooling measures are therefore required.

It is an object of the invention to present a structural unit with an electric machine for a drive train of a motor vehicle, in which the electric machine can be effectively cooled by simple means.

The above object is achieved by a structural unit according to the independent claim. In the dependent claims advantageous refinements and developments of the invention are given.

The proposed structural unit for a drive train of a motor vehicle has an electric machine arranged in a fluid chamber and a fluid-carrying drive train component. In this case, the electric machine comprises a stator and a rotor. The drivetrain component includes a fluid that can be acted upon by an operating pressure and a fluid port. In the assembly, the rotor and / or the stator at least in each case a fluid channel for cooling the electric machine, which is in fluid communication with the fluid connection by the fluid.

Such a unit can be used for cooling the components of the electric machine, the fluid circuit of a preferably adjacent to the electric machine fluid-carrying drive train component, wherein the electric machine by forming a fluid channel on or in the rotor and / or on the stator with an existing fluid circuit of the drive train component is connected. In this way, a fluid of the powertrain component is also used for cooling the electric machine, thereby the rotor and / or the stator can be cooled by heat conduction and exchange. For example, the fluid can communicate with the fluid channel formed on the rotor and / or stator via a fluid connection arranged in a housing of the drive train component. For this purpose, the fluid connection for the rotatable rotor may be e.g. be formed as an opening or as an at least partially circumferential groove, which axially or radially opposite to a correspondingly executed fluid passage portion of the rotor. For recirculation of the fluid and thus for the representation of a closed fluid circuit, the fluid space can have a fluid outlet fluidly connected to the fluid-carrying drive train component. This fluid outlet is favorably arranged in the installed state of the electric machine geodesically below the axis of rotation of the rotor and radially outside the extension of the rotor.

Particularly preferably, the fluid is a lubricant or an actuating means of the drive train component, in particular an oil. That is, the electric machine is designed as a fluid, in particular as an oil-cooled machine. Advantageously, the fluid can be introduced into the entire fluid space of the electric machine and sprayed there in particular.

With further advantage, the drive train component for generating the operating pressure to a fluid pressure source, which is preferably formed within the drive train component. This eliminates the need for a separate fluid pressure source.

The formation of the rotor fluid channel can be done, for example, within a rotor shaft of the electric machine. The fluid channel may be at least partially centrally within the rotor shaft, i. be executed coaxially or parallel to the axis of rotation of the rotor shaft. An off-axis, in particular axially parallel guidance of the cooling channel within the rotor shaft may be advantageous if the rotor shaft is designed as a hollow shaft and the central cavity for the arrangement, in particular for storage of other powertrain components or for rotationally fixed connection with a drive shaft of the drive train components is required. The fastening means for connection to the drive train component, in particular to the crankshaft of an internal combustion engine, can be circumferentially spaced from the fluid channel and, in this respect, can also be embodied on a same pitch circle diameter.

To realize a fluid cooling, the rotor carrier may also itself have a fluid channel, which may be in fluid communication with a fluid channel formed in the rotor shaft for cooling the electromagnetically active rotor parts.

With particular advantage, the fluid connection is formed on a drive shaft of the drive train component, which is in operative connection with the rotor for transmitting a torque. In this case, the drive shaft on a fluid channel, the is in fluid communication with the fluid channel formed on the rotor, for example on the rotor shaft, on the rotor carrier or a rotor laminated core. The drive shaft of the drive train component can be a drive shaft, an output shaft or an intermediate shaft. In this case, the fluid connection with the rotor can be carried out particularly pressure resistant.

According to an advantageous embodiment, the drive shaft of the drive train component can simultaneously represent the rotor shaft. In this case, the electromagnetically active part of the rotor is connected to or arranged on the drive shaft of the drive train component. Alternatively, the rotor shaft and the drive shaft may be formed separately and connected to each other axially or radially.

In a particularly preferred embodiment, the drive train component is designed as a gear change transmission, a torque-transmitting clutch or a drive unit. In the latter case, with further advantage, the rotor shaft may be formed as a crankshaft adapter of the drive unit.

For the separation of the fluid space of the electric machine, this can preferably be limited on an axial side by a housing wall of the fluid-carrying drive train component. In this case, even a fluid seal usually provided there, for example a shaft seal, can be dispensed with. The fluid space can preferably be limited on the other axial side expediently by a, a seal shield performing intermediate wall or by a housing wall of another drive train component, wherein required fluid sealant can be arranged functionally between the rotor shaft and the intermediate wall.

To enable the cooling of the free surfaces of the rotor and stator may be provided with further advantage a fluid outlet on the rotor shaft, from which emerge the cooling fluid and can wet the free surface areas of the electric machine. In this context, the fluid outlet may comprise or be designed as a spray nozzle for forming droplets, in particular a spray oil mist. To enable effective cooling of the fluid outlet of the rotor shaft is favorably arranged radially within a cylindrical support portion of the rotor carrier on which the electromagnetically active part of the rotor, in particular a rotor core stack is arranged. This type of cooling is particularly advantageous in internal electric rotor machines with a rotor arranged radially inside a stator.

For rotationally fixed connection with a drive train component, the rotor shaft can have rotational drive means, which are advantageously provided on a section of the rotor shaft located outside the fluid space.

To allow simultaneous effective cooling of the stator, the rotor may have fluid passageways which are conveniently located within the axial extent of the stator and radially adjacent to the stator. This embodiment is particularly advantageous in an electric internal rotor machine, wherein the rotor is arranged radially within the stator. As a result of centrifugal force, the fluid can pass through the fluid passageways of the rotor and then enter into a heat exchange contact with the stator, in particular with axial winding heads of a stator winding. The proposed cooling concept can be implemented efficiently, in particular with a permanent-magnet synchronous machine, but at the same time is not limited to such a machine.

In addition, an assembly for a previously described unit is proposed which comprises an electric machine with a rotor and a stator and wherein the rotor includes a rotor shaft and a fluid channel for establishing a fluid connection with a drive shaft of a fluid-carrying drive train component. The assembly further includes a seal plate performing an intermediate wall, which is connected to a stator of the stator and which is in a radially inner portion via a fluid sealant with the rotor shaft in sealing engagement. Such an assembly may already be advantageously prefabricated by a supplier and connected to a vehicle manufacturer with a provided drive unit.

Such an assembly includes in particular a solution, wherein the rotor fluid channel is embodied in the rotor shaft itself and wherein the drive shaft of the fluid-carrying drive train component itself has a fluid channel. When connecting rotor shaft and drive shaft thus the rotary driving connection and the fluid connection are made.

The invention will be explained by way of example with reference to the accompanying figures.

Show it:

1 a unit comprising an electric machine and an internal combustion engine, wherein the electric machine is connected to a lubricant circuit of the internal combustion engine and has a spray oil cooling of the rotor and the stator;

2 a unit according to 1 with a stator cooling duct running on the stator of the electric machine and connected to the lubricant circuit of the internal combustion engine;

3 a schematic representation of the fluid connection of a housing connection of an internal combustion engine with a rotor fluid passage of an electric machine.

1 shows a structural unit 10 for a drive train of a motor vehicle, which first one in a fluid space 12 arranged electric machine 14 with a rotor 16 and with a stator 18 includes. The rotor 16 has a rotor shaft rotatable about a rotation axis A. 20 , a rotor carrier 22 and a at there on a cylindrical support area 24 arranged rotor laminated core 26 with permanent magnets 28 on. The rotor 16 is including an air gap radially from the stator 18 surrounded, which is a stator lamination 30 with in the direction of the rotor 16 pointing stator teeth 32 includes. At the stator teeth 32 is a stator winding 34 arranged in the form of a single-tooth winding, in which for generating an electro-magnetic alternating field by means of a control unit, not shown here, a voltage of variable frequency and amplitude can be impressed. Next is the stator 18 by means of a stator carrier 36 and a screw connection 42 on a housing 38 one to the electric machine 14 axially adjacent drive train component, in particular an internal combustion engine 40 established. It can be seen that the electrical machine described 14 as a permanently excited machine in internal rotor design with a radially inside the stator 18 arranged rotor 16 is trained.

The internal combustion engine 40 has a crankshaft 44 as the output shaft, which with the present as a crankshaft adapter 20 executed rotor shaft 20 the electric machine 14 rotatably connected. These are on the crankshaft adapter 20 several Duchgriffsöffnungen 46 for bolts 48 provided, which with the crankshaft 44 be screwed.

For cooling the electric machine 14 this is via a fluid connection 50 of the internal combustion engine 40 with a lubricant circuit of the internal combustion engine 40 connected. For this purpose are in the rotor shaft 20 and in the drive shaft or the crankshaft 44 fluid channels in fluid communication with each other 52 . 54 formed by which when operating the internal combustion engine 40 under operating pressure fluid, in particular the lubricant from the internal combustion engine 40 in the electric machine 14 be passed and there heat exchange heat loss of the electric machine 14 can dissipate. The operating pressure of the lubricant is in a known manner by the lubricant or oil pump 56 of the internal combustion engine 40 built up. The rotor fluid channel 54 extends outside the axis of rotation A and at least over part of its extension parallel to the axis of rotation A and in a peripheral portion outside or between two through-openings 46 , This rotor fluid channel 54 opens in a roughly in the axial center of the rotor 16 and radially inside the cylindrical support portion 24 located fluid outlet 58 from which the fluid enters the closed fluid space 12 the electric machine 14 can occur.

The fluid space 12 is combustion engine side and peripherally by a housing wall 60 of the internal combustion engine 40 limited. At the of the internal combustion engine 40 remote axial side of the electric machine 14 is the fluid space 12 by a, a sealing shield performing intermediate wall 62 limited, being functional between the rotor shaft 20 and the partition 62 Fluid sealing means 64 are arranged in the form of a shaft seal. In 1 It can also be seen that the rotor shaft 20 outside the fluid space 12 Rotary drive means 66 in the form of a disc-shaped driver for non-rotatable connection with another, not shown here driveline component.

By the rotational movement of the rotor 16 can the fluid or the lubricant with a suitable dimensioning and design of the fluid outlet 58 be sprayed or atomized, then on the the rotor core 26 carrying rotor carrier 22 hold true. The fluid may continue on the inner peripheral surface of the rotor carrier 22 . 24 distribute and spread out there axially. The fluid also strikes the rotor 16 provided fluid passageways 68 which are within the axial extent of the stator 18 and are arranged radially adjacent thereto. The fluid is forcibly forced through these fluid passageways due to rotation 68 pressed radially outward and can winding heads of the stator winding 34 wet and cool (see arrows). After hitting wall areas 60 . 62 of the fluid space 12 The fluid can then be to a geodetically lower collecting section 70 within the fluid space 12 drain away from where it passes through a fluid outlet 72 depressurized back to a coincident with this embodiment in the fluid inlet 74 of the internal combustion engine 40 flow, there in a fluid reservoir 76 collect and circulate again in the manner described.

The one with respect to the lubricant at a higher temperature having electric machine 14 This way, except for one average lubricant temperature of the internal combustion engine 40 be cooled and tempered from about 80-100 ° C.

As an alternative to the illustrated spray oil cooling, the rotor carrier 22 also a fluid channel itself 23 having, for cooling the cylindrical support portion 24 with the in the rotor shaft 20 trained fluid channel 54 is in a fluid flow connection. This fluid channel 23 can be used as a circumferential inner cooling jacket on the rotor arm 22 be executed as this schematic in 2 is shown.

It is also possible regardless of the configuration of the rotor cooling and cooling of the Statorwickelköpfe, the stator 18 by means of a with the lubricant circuit of the internal combustion engine 40 fluidly connected stator cooling channel 78 or stator cooling jacket to cool, which at the peripheral region of the stator 36 and here by way of example together with the housing wall 60 is formed and serving as inlet and outlet schematically illustrated stator fluid connections 80 . 82 having ( 2 ). A stator cooling jacket can also be completely in a suitably designed stator 36 run or be limited solely by this.

According to the schematic representation in 3 can the fluid connection 50 of the internal combustion engine instead of in the crankshaft 44 also on the housing 60 of the internal combustion engine 40 be provided. This is in the fluid transfer area of internal combustion engine 40 and rotor 16 on the housing 60 a combustion engine side open circumferential groove 84 formed, which with the rotor fluid channel 54 and the fluid outlet 58 communicates. Axial to the groove 84 is in the combustion engine housing 60 as a part of the lubricant circuit, a fluid port 50 educated. By this arrangement can continuously fluid from the stationary housing 60 on the rotor shaft 20 be handed over. Of course, a circumferential groove instead of on the rotor shaft 20 also or additionally on the housing 60 be provided. It is not necessarily necessary to make the fluid transfer region fluid-tight. It is sufficient if one for cooling the electric machine 14 sufficient fluid flow is ensured. Leakage can be tolerated within certain limits.

• – die elektrische Maschine 14 mit dem Rotor 16 und mit dem Stator 18, wobei die Rotorwelle 20 einen Fluidkanal 54 zur Herstellung einer Fluidverbindung mit dem Antriebsaggregat 40 bzw. allgemein mit der Antriebsstrangkomponente aufweist und
• – die Zwischenwand 62, welche in einem radial äußeren Abschnitt mit dem Statorträger 36 des Stators 18 verbunden ist und welche in einem radial inneren Abschnitt über das dort angeordnete Fluid-Dichtmittel 64 mit der Rotorwelle 20 in Dichtverbindung steht.

In a production of the illustrated unit 10 For example, in order to simplify assembly at a vehicle manufacturer, an assembly may be pre-assembled which comprises at least the following elements:

• - the electric machine 14 with the rotor 16 and with the stator 18 , wherein the rotor shaft 20 a fluid channel 54 for establishing a fluid connection with the drive unit 40 or generally with the drive train component and
• - the partition 62 , which in a radially outer portion with the stator 36 of the stator 18 is connected and which in a radially inner portion via the there disposed fluid sealant 64 with the rotor shaft 20 in sealed connection.

When assembling the electric machine 14 with the internal combustion engine 40 becomes the stator carrier 36 together with the partition 62 or the seal plate by means of the screw 42 on the housing 60 of the internal combustion engine 40 established. Furthermore, the rotor shaft 20 with the crankshaft 44 screwed, whereby the connection of the formed there fluid channel 52 with the rotor fluid channel 54 will be produced.

LIST OF REFERENCE NUMBERS

10

unit

12

fluid space

14

electric machine

16

rotor

18

stator

20

rotor shaft

22

rotorarm

23

fluid channel

24

support area

26

Laminated core

28

permanent magnets

30

stator lamination

32

stator teeth

34

stator

36

stator

38

Engine housing

40

internal combustion engine

42

screw

44

crankshaft

46

Through opening

48

bolts

50

fluid port

52

fluid channel

54

fluid channel

56

pressure source

58

fluid outlet

60

housing

62

partition

64

sealant

66

Rotary drive means

68

Fluid passageway

70

collecting section

72

fluid outlet

74

fluid inlet

76

fluid reservoir

78

Stator cooling channel

80

fluid port

82

fluid port

84

groove

Claims (15)

Assembly ( 10 ) for a drive train of a motor vehicle, comprising - one in a fluid space ( 12 ) arranged electrical machine ( 14 ) with a rotor ( 16 ) and with a stator ( 18 ), - a fluid-carrying drive train component ( 40 ), which is acted upon by an operating pressure fluid and at least one fluid connection ( 50 ), wherein - the rotor ( 16 ) and / or the stator ( 18 ) at least one respective fluid channel ( 54 . 78 ) for cooling the electric machine ( 14 ), which communicates with the fluid connection ( 50 ) of the driveline component ( 40 ) is in flow communication. Assembly according to claim 1, characterized in that the fluid is a lubricant or an actuating means of the drive train component ( 40 ). Assembly according to claim 1 or 2, characterized in that the drive train component ( 40 ) a fluid pressure source ( 56 ) for generating the operating pressure. Assembly according to one of claims 1-3, characterized in that the rotor fluid channel ( 54 ; 23 ) within a rotor shaft ( 20 ) and / or a rotor carrier ( 22 ) is trained. Assembly according to one of claims 1-4, characterized in that the fluid connection ( 50 ) on a drive shaft ( 44 ) of the driveline component ( 40 ) and with the rotor fluid channel ( 54 ; 23 ) is in fluid communication and that the drive shaft ( 44 ) with the rotor ( 16 ) is in operative connection for transmitting a torque. Assembly according to claim 5, characterized in that the drive shaft ( 44 ) of the driveline component ( 40 ) at the same time the rotor shaft ( 40 ). Assembly according to claim 5, characterized in that the rotor shaft ( 20 ) and the drive shaft ( 44 ) are formed separately and firmly connected to each other. Assembly according to one of claims 1-7, characterized in that the drive train component is a gear change transmission, a torque-transmitting clutch or a drive unit ^ ( 40 ). Assembly according to claim 8, characterized in that the rotor shaft ( 20 ) as a crankshaft adapter of the power plant ( 40 ) is trained. Assembly according to one of claims 1-9, characterized in that the fluid space ( 12 ) on an axial side by a housing wall ( 60 ) of the fluid-carrying drive train component ( 40 ) is limited. Assembly according to one of claims 1-10, characterized in that the fluid space ( 12 ) on an axial side by a, a seal shield performing intermediate wall ( 62 ) or limited by a housing wall of another drive train component. Assembly according to one of claims 1-11, characterized in that the rotor shaft ( 20 ) a fluid outlet ( 58 ) having. Assembly according to one of claims 1-12, characterized in that the rotor shaft ( 20 ) at a portion outside the fluid space rotary driving means ( 66 ) for non-rotatable connection with another drive train component. Assembly according to claim 13, characterized in that the rotor ( 16 ) Fluid passageways ( 68 ), which within the axial extent of the stator ( 18 ) and radially adjacent to the stator ( 18 ) are arranged. Assembly for a structural unit ( 10 ) according to one of claims 11-14 comprising - an electric machine with a rotor ( 16 ) and with a stator ( 18 ), wherein the rotor ( 16 ) a rotor shaft ( 20 ) and a fluid channel ( 54 ) for establishing a fluid connection with a fluid-carrying drive train component ( 40 ) and comprising - a sealing shield representing an intermediate wall ( 62 ), which with a stator ( 36 ) of the stator ( 18 ) and which in a radially inner portion via a fluid-sealing agent ( 64 ) with the rotor shaft ( 20 ) is in sealing connection.

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