AT525415A1 - Electrical machine and drive unit with such an electrical machine - Google Patents

Abstract

The invention relates to an electrical machine (1) with a rotor (3) that can be cooled by cooling liquid (4). The electrical machine (1) comprises a rotor shaft (9) with a rotor axis of rotation (2) and a lamella pack (8) fixed to the rotor shaft (9) in a rotationally fixed manner and consisting of a plurality of magnetizable rotor laminations (10) lined up along the rotor axis of rotation (2). . At least one axial front end (6, 7) of the disk set (8) has a conveying and distribution device (5) that uses centrifugal forces for the coolant to be supplied to the disk set (8), which conveying and distribution device (5) has at least one coolant Inlet (14) and at least one cooling liquid outlet (15). A radial distance (R1) of the at least one cooling liquid outlet (15) relative to the rotor axis of rotation (2) is greater than a radial distance (R2) of the at least one cooling liquid inlet (14) relative to the rotor axis of rotation (2). Functionally reliable cooling of the electrical machine (1) that requires as little maintenance as possible and is at the same time intensive can be achieved with this.

Description

electric machine as specified in the claims.

JPH09163682A describes a cooled rotor of an electrical machine whose rotor speed can exceed more than 3,600 rpm. The rotor is provided with an encapsulation, which encapsulation comprises a hollow cylinder and end plates at the axial ends of the hollow cylinder. The hollow cylinder is dimensioned in such a way that its inner lateral surface is at a distance from the outer cylindrical lateral surface of the rotor and thus forms a hollow-cylindrical annular gap around the rotor. The hollow-cylindrical annular gap is intended for the passage of cooling liquid. This cooling liquid is supplied to a first axial end of the rotor shaft by external pressurization from a pump. In particular, the cooling liquid is fed to the interior of the encapsulation via a first axial center bore in the rotor shaft and injected under corresponding pressure into the hollow-cylindrical annular gap. The cooling liquid is drained off the rotor again via a second axial center hole at the second axial end of the rotor shaft. This known rotor cooling is complex in terms of construction and has negative effects on the electrical or electromagnetic performance of the electrical

Machine.

DE102019211555A1 discloses a cooling fluid guiding arrangement for cooling a rotor of an electrical machine that is connected to a rotor shaft. A closed cooling fluid circuit is proposed in which a cooling

fluid guide sleeve is involved. The rotor shaft is designed in two parts axially,

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Rotor shaft structurally complex and therefore relatively expensive.

The object of the present invention was to overcome the disadvantages of the prior art and to provide an electric machine with a rotor that can be cooled by cooling liquid, with these cooling measures being designed to be as structurally complex as possible, to be implemented as cost-effectively as possible and to have the achievable performance of the electrical machine as little or as little as possible. In addition, an optimal

specified drive unit for an electrically driven motor vehicle.

This object is achieved by an electrical machine according to the claims

solves.

The electric machine according to the invention has a rotor that can be cooled by cooling liquid. The coolant is preferably provided for circulation through the rotor or its disk pack. The corresponding rotor includes a rotor shaft which defines a rotor axis of rotation. On the rotor shaft, a disk set is mounted in a rotationally fixed manner, which disk set has a plurality of magnetizable rotor disks lined up along the rotor axis of rotation. The laminated core can be formed from discs made of electrical sheet steel that are lined up without a gap. At least one axial end of the

Rotor or the disk pack is a centrifugal forces and rotary movements

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NEN cooling liquid inlet relative to the rotor axis of rotation.

Due to the conveying and distribution device specified, it is not absolutely necessary to provide an additional cooling medium pump or one arranged externally to the housing of the electrical machine for cooling the rotor. For example, a partial flow of cooling liquid from a pump that is already present, in particular a transmission oil pump or a hydraulic oil pump, can be branched off and used to supply the conveying and distribution device arranged on the rotor or on the rotor shaft of the electric machine with a corresponding quantity of cooling liquid, such as Example of transmission or hydraulic

raulic oil.

The pressure of the coolant at the coolant inlet of the conveying and distribution device can be very low, in particular it can only be designed as a gravity inlet or as an open flow gradient for the coolant, i.e. without any significant pressure increase by the upstream pump or without maintaining a minimum fluid pressure. Rather, the pressure increase is used by the conveying and distribution device rotating together or synchronously with the rotor in order to distribute the cooling liquid supplied without pressure or almost without pressure in relation to the rotor or its disk pack. Accordingly, a centrifugal or

Trained centrifugal pump for coolant.

It is also advantageous that complex rotary feedthroughs or shaft sealing rings between rotating and stationary elements of the electrical machine can be avoided because the conveying and distribution device requires a

part of the rotor or is an integral part of the electrical machine

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can be done.

The conveying and distribution device using centrifugal forces is non-rotatably connected to the rotor shaft and/or the disk pack and is set up to increase the pressure of the cooling liquid at the cooling liquid outlet compared to the pressure of the cooling liquid at the cooling liquid inlet. Accordingly, the conveying and distribution device is rotationally coupled to the rotor and speed synchronism is thus ensured. The construction is structurally as simple as possible and functionally reliable in the long term. In addition, is

thereby a compact and robust assembly can be achieved.

Alternatively, it is also conceivable that the conveying and distribution device is rotatably connected to the rotor shaft and/or the disk pack with the interposition of a gear, in particular a reduction gear, in order to achieve different speeds between the conveying and distribution device and the rotor and to keep the delivery or distribution pressure of the coolant below an upper limit. However, such an interposed transmission increases the constructive or structural

Expense.

According to an expedient embodiment, the cooling liquid inlet can be provided for the purpose of supplying cooling liquid to the conveying and distribution device preferably only under the influence of gravity or only with ambient pressure. A quasi-open flow gradient for the cooling liquid to be supplied advantageously eliminates the need for complex sealing measures and any maintenance cycles. The pressure of the coolant required for effective coolant distribution and cooling of the rotor is determined in a simple manner by centrifugal forces based on the conveying and distribution device or based on the speed of the rotor of the electrical machine.

co-determined.

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Cooling medium pump can be operated with very low drive power.

According to an advantageous development, it can be provided that a first pressing element is designed to apply an axial pressing force in relation to a first axial end of the disk pack. This ensures that the individual disks or predefined partial disk sets of the disk set are pressed firmly against one another in the axial direction, so that they rest against one another with as few gaps as possible or over the entire surface. If cooling channels are formed through the disk pack, ie within the disk pack, undesirable leaks with cooling liquid can thus occur between individual disks

be held back.

According to an expedient embodiment, a second pressing element can be designed to apply an axial pressing force in relation to a second axial front end of the disk pack. As a result, a mutual contact pressure of the individual disks that is as homogeneous as possible over the axial length of the disk pack can be achieved. In particular, inequalities in the mutual contact pressure caused by frictional forces can be improved

be held back.

At least one of the pressing elements can comprise a pressure washer or pressure plate and a threaded nut. One of the axial pressing elements opposite the disk set could also be designed as one piece with the rotor shaft.

tes abutment, in particular as a flange, be designed.

According to an advantageous further development, a plurality of cooling liquid channels distributed over the circular cross section of the rotor is formed.

det, which pass through the disk set in the axial direction of the rotor, where

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the pressure of the cooling liquid in the cooling channels can be kept relatively low.

It is expedient if the pressure of the cooling liquid in the cooling ducts remains below 10 bar even when the rotor is at its maximum speed. The maximum pressure of the conveying and distribution device at the maximum speed of the rotor can be predetermined in a simple manner by the geometry of the same, in particular by the radial distances between the cooling liquid inlet and the cooling liquid outlet being influenced as required. The problem of leaks in the direction transverse to the duct extension can be kept to a minimum as a result. In addition, simple or standard sealing measures can suffice or the requirements for the sealing effect can be met

between the individual slats can be met easily and inexpensively.

The cooling channels preferably run continuously between the first and the second axial end face of the disk pack. The conveying and distribution device feeds the individual cooling channels with cooling liquid, which then ensures that heat is removed from the interior of the disk pack. As a result, a good cooling effect can be achieved after the heat is dissipated directly from the inside of the fin pack or close to the source of the heat.

heat can be absorbed by the coolant.

The coolant channels run through the disk pack in the axial direction. They are each closed in themselves, ie bordered or closed in the transverse direction to their longitudinal axes. The coolant channels can be in the form of bores with a circular or approximately round, in particular

be designed with an elliptical or polygonal cross-section.

Furthermore, it can be expedient if the conveying and distribution device comprises an annular channel in or on the first pressing element, with the cooling

liquid channels in the disk pack are fluidically coupled to the annular channel.

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functional and functional.

It is expedient if the conveying and distribution device for the cooling liquid is

sigkeit is carried out wingless. In particular, the encircling ring channel or the ring channel bottom of the conveying and distribution device can be designed to be smooth or planar, that is to say without radial projections. This makes one

the simplest, lightest and most robust construction possible.

The conveying and distribution device is advantageously arranged inside the outer housing of the electrical machine, ie surrounded by the housing of the electrical machine. In addition, the conveyor and distribution device uses for their

Operating the rotational energy of the rotor of the electric machine.

Furthermore, it can be provided that the ring channel has the cooling liquid inlet lying radially on the inside and has the at least one cooling liquid outlet lying radially further on the outside. In this way, the pressure exerted by the coolant can be controlled or kept below a predetermined limit value in a simple manner. Above all, by suitably selecting the radial height of the liquid column, which can be influenced by the radial distances of the cooling liquid inlets and outlets, and by suitably selecting the radial distance of the liquid column from the rotor axis of rotation, the pressure of the cooling liquid in the cooling channels or relative to the disk pack influenced or adjusted as required, in particular limited. In particular, this allows the pressure exerted by the cooling liquid in the cooling channels to be within a pressure range that can be controlled for the tightness requirements of the disk pack or below it in a simple manner

a predetermined upper pressure limit.

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liquid, for example an oil ring, is formed.

In addition, it can be provided that the cooling liquid inlet is arranged at a distance to the outside in the radial direction in relation to an outer lateral surface of the rotor shaft. This prevents the coolant from being fed along the axis of rotation of the rotor or via the center of the rotor shaft and the pressure built up in the coolant, which is dependent on centrifugal force, can thus be kept well manageable even at high speeds of the rotor. Leakages of the cooling liquid between the side or main surfaces of rotor lamellae arranged in a row can thus be reliably avoided or can be prevented with simple sealing and/or pressing measures for the lamellar set

sufficient to be found.

Also advantageous is an embodiment according to which it can be provided that the radial distance of the at least one cooling liquid inlet relative to the rotor axis of rotation is larger than the largest radius of the rotor shaft. As a result, the pressure of a cooling liquid in the disk pack of the rotor remains relatively low or within a range of values that can be easily controlled, even at high rotor speeds. In particular, an undesired escape of cooling liquid from the cooling channels, in particular between immediately adjacent disks of the disk pack, can be prevented even at high speeds of the rotor. Accordingly, the requirements for sealing in the area between the individual lamellae can be kept relatively low and an undesired escape of cooling liquid between individual lamellae of the lamellar set can be avoided even with standard sealing concepts even at high rotor speeds. between neighboring

leaking cooling liquid would be carried out in the narrowest possible way

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being constructed.

According to a development, it is possible for the rotor shaft to be designed as a hollow shaft, which hollow shaft can be pushed through centrally by an output shaft of a reduction gear, and which reduction gear is rotationally connected to the rotor shaft on the input side. With such a hollow shaft of the rotor, which is penetrated by a transmission output shaft, the achievable cooling effect for the disk pack is relatively poor if the cooling liquid is supplied via the remaining hollow-cylindrical annular gap in the hollow shaft. This can be remedied by supplying the cooling channels within the disk pack

with cooling liquid passed through in the axial direction.

Furthermore, it can be expedient if the ring channel is delimited at least in sections by a metal ring that is essentially L-shaped or U-shaped in cross section, which metal ring is fastened to an axially outer end face of the first pressing element, in particular is connected to the first pressing element by means of a press fit . As a result, an annular channel can be implemented which has the lowest possible weight and can be produced in an advantageous manner in terms of production technology. In addition, the cross-sectional geometry of the ring channel can be optimally or simply adapted to fluid technology requirements, such as flow turbulence,

be adjusted.

In addition, it can be provided that the second axial front end of the rotor or the disk pack has an annular cooling liquid collecting channel

is assigned whose center point is on the rotor axis of rotation and whose ring plane is transverse to the rotor axis of rotation. As a result, the cooling liquid emerging from the cooling channels can be reliably collected even at high speeds of the rotor. Through an outflow opening located at the lower end or in the lower section of the collecting channel in relation to the vertical direction

the cooling liquid can be collected and drained off in a targeted manner,

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without excessive turbulence or aerosol formations starting from

caused by the coolant.

Furthermore, it can be provided that the cooling liquid collecting duct comprises a cooling liquid collecting ring which is non-rotatably or rigidly connected to a housing or to the stator of the electrical machine and is provided for cumulatively receiving cooling liquid escaping from the cooling liquid ducts of the disk pack. As a result, an annular collecting channel can be implemented which has the lowest possible weight and can be produced in an advantageous manner in terms of production technology. The relative to the rotor stationary or rigidly arranged collection channel can also act as a cyclone for the coolant emerging from the rotor and can thus prevent excessive aerosol formation with the coolant within the housing of the electrical

keep the machine behind.

According to one particular embodiment, it is possible for the cooling liquid collection duct and/or the cooling liquid collection ring to have a drainage opening for accumulated cooling liquid at its lowest point in the vertical direction or lower section, which drainage opening is provided for the fluidic connection of the cooling liquid collection duct with a cooling liquid reservoir, in particular is provided for fluidic connection with an oil sump in a transmission downstream of the electric motor. As a result, a closed circuit for a cooling liquid formed by oil can be set up in a simple manner. In addition, the oil in the gearbox can also be used to cool the rotor or its disk pack.

the.

According to an advantageous development, it can be provided that the cooling liquid channels in the disk pack run parallel to the axis of rotation of the rotor. This supports a simple and cost-effective manufacturability of the electrical

mechanical machine.

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In particular, it can be advantageous if the cooling liquid channels in the disk pack are formed by fluidly communicating openings in a plurality of individual disk sub-packages, so-called "disk stacks", and these disk sub-packages are lined up directly next to one another along the rotor axis of rotation. This allows in a simple way also relative

long coolant channels are formed within the disk pack.

Furthermore, it can be expedient if the first pressing element on the first axial front end and the second pressing element on the second axial front end of the disk pack are structurally and geometrically identical. This creates a common parts concept; which a cost-effective construction of

electric machine supported.

In addition, it can be provided that the first and/or the second pressing element is provided for the application of material removals for balancing the rotor, in particular is provided for the application of balancing bores. As a result, the at least one pressing element advantageously has multifunctionality, namely a pressing function for the rotor vanes, a supply and distribution function for cooling liquid with respect to the rotor

lamellae, and a balancing function for the rotor of the electrical machine.

The object of the invention is also achieved by a drive unit for an electric

vehicle as defined in the claims.

This drive unit comprises an electric machine and a reduction gear connected downstream of the electric machine, the electric machine being designed according to the claims. The technical effects and advantageous effects that can be achieved in this way are subject to the above and the following descriptions.

to be found in the writing.

For a better understanding of the invention, this is based on the following

Figures explained in more detail.

They each show in a greatly simplified, schematic and, in some cases, partial

Depiction:

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Fig. 1 shows a longitudinal section through an electrical machine and a downstream transmission, which electrical machine has an open or channel-like inlet for cooling liquid compared to a circular

having a conveying and distribution device arranged on the gate side;

Fig. 2 shows a cross section through the electrical machine or through its Ro-

gate according to Fig. 1;

3 shows a longitudinal section through an electrical machine and a downstream transmission, which electrical machine has a closed or pressure channel-like inlet for cooling liquid in relation to a conveying and distribution device arranged on the rotor side.

points;

Fig. 4 shows a cross section through the electrical machine or through its Ro-

gate according to Fig. 2;

5 shows a longitudinal section through an electrical machine with an internal rotor, with a conveying and distribution device using centrifugal forces being installed on an axial end face of the disk pack of the rotor.

direction is designed for cooling liquid.

As an introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numbers or the same component designations, it being possible for the disclosures contained throughout the description to be applied to the same parts with the same reference numbers or the same component designations. The position information selected in the description, such as top, bottom, side, etc., is related to the figure directly described and shown and these position

information to be transferred to the new position in the event of a change in position.

1 shows a schematic of an embodiment of the electrical machine 1 in longitudinal section, in particular along its rotor axis of rotation 2. FIG

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with electrical supply energy, at least its rotor 3 is actively cooled, in particular with a suitable cooling liquid 4 for dissipating heat

energized.

A delivery and distribution device 5 for the cooling liquid 4 is designed for this purpose, which delivery and distribution device 5 uses centrifugal forces originating from the rotor 3 rotating during operation of the electrical machine 1 . The conveying and distribution device 5 is po-

positioned or attached.

The magnetically relevant disk pack 8 is fixed in a rotationally fixed or rigid manner on a rotor shaft 9 . The rotor shaft 9 defines the rotor axis of rotation 2 of the rotor 3. The lamination stack 8 has, in a manner known per se, a plurality of magnetizable rotor lamination 10 arranged in a row along the rotor axis of rotation 2, in particular with as few gaps as possible. This in the axial direction, ie. Rotor laminations 10 quasi-stacked along the rotor axis of rotation 2 typically have a thickness measured along the rotor axis of rotation 2 of less than 1 mm. According to the illustrated embodiment, a plurality of rotor lamellae 10 can be bundled or combined, in particular form partial lamellae packets 11 or so-called lamellae stacks. Several lamellar partial packets 11 arranged in a row along the rotor axis of rotation 2 , for example six identical lamellar partial packets 11 , then form the magnetizable lamellar packet 8 . Alternatively, the disk pack 8 can be designed without disk sub-packages 11, i.e. from a large number of individual disks 10

be composed.

As is known per se, the individual slats 10 can be electrically insulated from one another and glued to one another, in particular via an adhesive and/or iso

lation layer be connected to each other on their side or contact surfaces.

As can be seen above all from FIG. 2, several attachments can be

ducts 12 can be designed, which are used to accommodate or hold persons

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magnetic magnets 13 are provided. This plurality of individual permanent magnets 13 is distributed essentially over the circumference or the outer surface of the rotor 3 . The corresponding arrangement or distribution and number of permanent magnets 13 determines the number of magnetic poles or number of pole pairs of the rotor 3. The receiving channels 12 preferably run in a

an angle to the radius of the rotor 3.

The conveying and distribution device 5 for the cooling liquid 4, which uses the rotational movements or centrifugal forces of the rotating rotor 3, has at least one cooling liquid inlet 14 and at least one cooling liquid outlet 15. A radial distance R1 of the at least one cooling liquid outlet 15 relative to the rotor axis of rotation 2 is greater than a radial distance R2 of the at least one cooling liquid inlet 14 relative to the rotor axis of rotation 2. The fluid pressure of the cooling liquid 4 built up by the conveying and distribution device 5 can the nominal or maximum speed of the rotor 3 or within the nominal speed range of the rotor 3 to a predetermined level or to a predetermined value range compared to the supply pressure of the

Coolant 4 or are raised from the ambient pressure.

According to an expedient embodiment, the radial difference AR between the at least one stationary cooling liquid inlet 14 and the at least one cooling liquid outlet 15 rotating during operation of the electrical machine 1 is less than 15 mm, preferably less than 10 mm.

in particular less than 5 mm.

The cooling liquid 4 can include water, which can be mixed with anti-rust and/or anti-freeze additives, for example glycol. Likewise, other fluids can be used, such as oils, in particular also oils from transmission and/or hydraulic components of a motor vehicle that are already present, which motor vehicle by means of the claimed

electrical machine 1 can be driven.

The conveying and distribution device 5 using centrifugal or centrifugal forces Fz

is rotatably connected to the rotor shaft 9 and the disk pack 8 and to

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set up, the pressure of the cooling liquid 4 at the cooling liquid outlet 15 against

to be raised above the pressure of the cooling liquid 4 at the cooling liquid inlet 14 .

The conveying and distribution device 5 rotates during operation of the electric machine 1 about the rotor axis of rotation 2, in particular there is speed synchronicity or speed equality between the rotor 3 and the conveying and distribution device 5. The caused by the rotating rotor 3, respectively the centrifugal or centrifugal force Fz exerted by the conveying and distribution device 5 acts on the coolant 4 supplied. In addition to the angular velocity w of the rotor 3, the mass m or the density p of the cooling liquid 4 is also an influencing factor on the pressure p exerted by the cooling liquid 4 in relation to the disk pack 8 or in relation to the at least one cooling liquid channel 22. In particular, the relationships or the essential influencing factors on the centrifugal force-dependent pressure p by the following formula

be displayed:

Fz=mwir _ R2 p=pWw? ff, AR

The cooling liquid inlet 14 is intended to supply cooling liquid 4 under the influence of gravity or at ambient pressure. Accordingly, an unpressurized cooling liquid inlet 14 based on an open flow gradient 16 is preferably provided for the conveying and distribution device 5 . As can be seen from the embodiment according to Fig. 1, the liquid inlet 14 can have a stationary or housing-fixed flow edge 17, in particular a drip or liquid nose, which acts as a boundary edge between the stationary section and the rotating section of the liquid inlet 14 acts. Immediately after this flow edge 17, the cooling liquid 4 is transferred or transferred to or into the rotatingly mounted conveying and distribution device 5. This means that complex rotary unions or sealing measures with complex and maintenance-prone sealing elements can be avoided.

ments, such as shaft sealing rings (Simmerings), are dispensed with.

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According to the illustration in FIG. 1 , the open flow gradient 16 for supplying coolant 4 to the conveying and distribution device 5 can run below a rotary bearing of the rotor shaft 9 in relation to the longitudinal center plane of the electrical machine 1 . In particular, the open flow gradient 16 does not run through the rotor pivot bearing, so that turbulence in the cooling liquid 4 is held back by the rotor pivot bearing. For example, this rotor

Pivot bearing designed as a ball bearing.

As an alternative to the above-described supply of coolant to the conveying and distribution device 5 based on an open flow gradient 16, the coolant 4 can also be supplied from a pump arranged externally to the electric machine 1 at a pressure of less than 1 bar, in particular less than 0.5 bar, the conveying and distribution device 5

to supply

The conveying and distribution device 5 comprises a self-contained ring channel 18 for the cooling liquid 4, which ring channel 18 can be rotated about the rotor axis of rotation 2 in relation to its ring plane 19 . The ring channel 18 is preferably formed in and/or on a first pressing element 20 . This first pressing element 20 is provided for applying an axial pressing force in relation to the first axial front end 6 of the disk set 8 . The annular channel 18 has the coolant inlet 14 lying comparatively further inwards in the radial direction and lying comparatively further outwards in the radial direction

the at least one cooling liquid outlet 15.

The ring channel 18 rotating during the operation of the electrical machine 1 can be delimited at least in sections by a metal ring 21 that is essentially L-shaped or U-shaped in cross section. The metal ring 21 can be attached to an axially outer end face of the first pressing element 20, in particular

be firmly connected to the first pressing element 20 by means of a press fit.

In the embodiment according to FIGS. 1 and 2, but also in the embodiment according to FIGS. 3 and 4 described in detail below, a plurality

number of over the circular cross section -- Fig. 2 -- of the rotor 3 arranged distributed

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Cooling liquid channels 22 are formed, which pass through the disk pack 8 in the axial direction of the rotor 3 . The delivery and distribution device 5 is set up to transfer supplied cooling liquid 4 into this plurality of cooling liquid channels 22 . This enables heat to be dissipated directly from the interior or from the core of the disk pack 8 . The cooling liquid ducts 22 preferably run continuously between the first and second axial front ends 6, 7 of the disk pack 8. All or at least some of the cooling liquid ducts 22 preferably run in a straight line, as is shown in FIG. It is also a course deviating from a straight line, in particular a curved, wavy or meandering course of at least one

the coolant channels 22 possible.

The cooling liquid channels 22 in the disk pack 8 are fluidically coupled to the annular channel 18 . In particular, there are fluidic connections between the cooling liquid channels 22 and the annular channel 18 of the conveying and distribution device 5. Accordingly, the conveying and distribution device 5 has a plurality of cooling liquid outlets 15, which each flow into the cooling liquid

ness channels 22 pass over.

As can best be seen from FIG. 2, a plurality of axially running cooling ducts 22 are provided, distributed over the circular cross section of the rotor 3 or the disk pack 8 . In this case, pairs of cooling channels 22 positioned close to one another can also be provided. It can be expedient to position the cooling channels 22 close to the permanent magnets 13 or close to their receiving channels 12, as can be seen in FIG. 2 by way of example. The cooling liquid channels 22 in the disk set 8 can be axially parallel to the rotor rotation

axis 2 run.

As can also best be seen from the two embodiments according to FIGS. 1 and 3, a second pressing element 30 can be designed to apply an axial pressing force in relation to the second axial front end 7 of the disk set 8 . Alternatively, an abutment formed in one piece or inseparably with the rotor shaft 9, in particular a support flange, could also be provided

be.

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The cooling liquid inlet 14 via the flow gradient 16 is formed in a lower partial section in the vertical direction, in particular in the lower half of the conveying and distribution device 5 and is accordingly only provided singularly or within a bottom dead center or within a lower circular section of the annular channel 18. A supply opening 23 for the cooling liquid 4 of the rotor 3 can be positioned in the outer housing 24 of the electrical machine 1 below the axis of rotation 2 of the rotor. In particular, this feed opening 23 can be provided approximately at position 4 o'clock (120°) or 8 o'clock (240°) with respect to the cross-sectional plane of the rotor 3, as indicated schematically in FIG. 1 with a dashed circle. This causes the supplied cooling liquid 4 to be swirled by the rotor shaft 9 or by the transmission output shaft 25

held back.

In the embodiment according to FIGS. 1, 2, the supply of cooling liquid 4 to the conveying and distribution device 5 does not take place via the rotor shaft 9 designed as a hollow shaft 26. The supply takes place via the outside of the hollow

shaft 26, open flow gradient 16 for the coolant 4.

In the embodiment shown in Figs. 1, 2 and also in Figs. 3, 4, the rotor shaft 9 is designed as a hollow shaft 26, which hollow shaft 26 can be pushed through centrally by an output shaft 25 of a reduction gear 27, not shown in detail, and which Reduction gear 27 is connected on the input side to the rotor shaft 9 for rotational movement. The rotor shaft 9 is therefore designed to be coaxial with the output shaft 25 . The reduction gear 27 can be designed as a planetary gear, not shown in detail, whose sun gear is connected to the rotor shaft 9 in a torque-proof manner. The electric machine 1 and the reduction gear 27 are arranged in series or side by side with respect to the axial direction of the rotor axis of rotation 2 and form a one-piece drive unit 28 for

connected to an electric vehicle.

As can also be seen from the embodiment according to FIGS. 1, 2, the coolant inlet 14 is in the radial direction outwards compared to an outer one

Lateral surface 29 of the rotor shaft 9 arranged at a distance. It can expediently

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be at when the radial distance R2 of the at least one cooling liquid inlet 14 relative to the rotor axis of rotation 2 is larger than the largest radius R3 of the rotor shaft 9.

The first and/or the second pressure element 20 , 30 can comprise a pressure disk 31 , 32 , in particular pressure plates, guided in the axial direction on the rotor shaft 9 , and a threaded nut 33 , 34 on the rotor shaft 9 . Instead of a threaded nut 33, 34, it is also possible for the at least one pressure disk 31, 32 to have an internal thread opposite the rotor shaft 9. The first pressing element 20 on the first axial end face 6 and the second pressing element 30 on the second axial end face 7 of the disk set 6 can be constructed

Lich and geometrically identical.

As can best be seen from Fig. 1, the second axial front end 7 of the rotor 3 or the disk pack 8 can be assigned an annular cooling liquid collecting channel 35, the center point of which is on the rotor axis of rotation 2

lies and whose annular plane runs transversely to the axis of rotation 2 of the rotor.

The cooling liquid collecting channel 35 can comprise a cooling liquid collecting ring 36, which is non-rotatably or rigidly connected to the outer housing 24 or to a stator 37 of the electric machine 1 and is provided for the cumulative intake of cooling liquid 4 escaping from the cooling liquid channels 22 of the disk set 8 . The cooling liquid collecting duct 35 and/or the cooling liquid collecting ring 36 has, at its lowest point or lower section in the vertical direction, a drainage opening 38 for cooling liquid 4, which drainage opening 38 is provided for the fluidic connection of the cooling liquid collecting duct 35 with a cooling liquid reservoir 39 , In particular for fluidic connection with an oil sump 40 in a reduction gear 27 downstream of the electrical machine 1.

is seen.

As is known per se, the stator 37 of the electrical machine 1 comprises a substantially hollow-cylindrical stator core, not shown in detail, and we

at least one electrical stator winding, not shown in detail.

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The cooling liquid channels 22 in the disk set 8 can be formed by fluidly communicating openings 41 in a plurality of individual disk sub-sets 11, in particular in so-called "disk stacks", which disk sub-sets 11 along the rotor axis of rotation 2 directly adjoining

are ranked.

The first and/or the second pressing element 20, 30 can be provided for attaching or introducing material removals 42 for balancing the rotor 3. In particular, at least one of the pressing elements 20, 30 for attachment

be designed by balancing holes 43 for the rotor 3.

3, 4 show a further embodiment of the electrical machine 1, which may be independent of itself, with the same reference numerals or component designations as in the previous FIGS. 1, 2 being used for the same parts. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding FIGS

taken.

Here, the coolant is fed to the conveying and distribution device 5 via

the interior of the rotor shaft 9 designed as a hollow shaft 26. The pressing elements 20, 30 each have connections running radially and axially to the rotor axis of rotation 2.

tion channels 44, 45 between the interior of the hollow shaft 26 and the cooling liquid channels 22 in the disk pack 8. In particular, in the first pressing element 20 there are a plurality of first connecting channels 44 which run in a star shape or radially to the rotor axis of rotation 2 and with which cooling liquid 4 from the interior of the

Hollow shaft 26 can be transferred into the coolant channels 22 in the disk set 8 .

In the second pressing element 30 there can be several second connection channels 45 running in a star shape or radially to the axis of rotation 2 of the rotor, with which cooling liquid 4 can be fed back into the hollow shaft 26 from the cooling liquid channels 22 in the disk set 8 . The coolant 4 discharged from the disk pack 8 can flow back into the coolant reservoir 39, in particular in

flow back the oil sump 40.

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In the embodiment according to FIGS. 3, 4, the pressure prevailing in the cooling liquid channels 22 of the cooling liquid 4 passed through is due to the comparatively high liquid column in the radial direction to the rotor axis of rotation 2

dentially higher than in the advantageous embodiment according to FIGS. 1, 2.

Fig. 5 illustrates an embodiment of the electrical machine 1, in which the conveying and distribution device 5 using centrifugal forces is assigned to the first axial front end 6 of the disk set 8 or is firmly connected to it, but the disk set 8 has no axially running, the disk set Has 8 penetrating coolant channels. In particular, a cooling device is shown here, which mainly on at least one of the

axial end faces of the plate pack 8 acts.

In the embodiment according to FIG. 5, the cooling liquid 4 is primarily applied to at least one of the two axial end faces by means of the conveying and distribution device 5.

surfaces or front ends 6, 7 of the disk pack 8 applied or sprayed.

The at least one cooling liquid inlet 14 is positioned close to the outside diameter of the rotor shaft 9 . The at least one cooling liquid outlet 15 is positioned comparatively further out in the radial direction. In particular, it can be positioned comparatively closer to the circumference of the disk pack 8 . Several impact or deflection surfaces 46 on the conveying and distribution device 5 can for an intensive distribution or for a targeted supply of

Coolant 4 provide.

The exemplary embodiments show possible variants, whereby it should be noted at this point that the invention is not limited to the specifically illustrated variants of the same, but rather that various combinations of the individual variants are also possible with one another and that this possibility of variation is based on the teaching on technical action through the present invention in Ability to work in this technical field

expert lies.

N2021/27200-AT-00

The scope of protection is determined by the claims. However, the description and drawings should be used to interpret the claims. Individual features or combinations of features from the different exemplary embodiments shown and described can represent independent inventive solutions. The independent inventive solutions

underlying task can be taken from the description.

All information on value ranges in the present description is to be understood in such a way that it also includes any and all sub-ranges, e.g. the information 1 to 10 is to be understood in such a way that all sub-ranges, starting from the lower limit 1 and the upper limit 10, are also included , i.e. all subranges start with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

Finally, for the sake of order, it should be pointed out that in order to better understand the structure, some elements are not to scale and/or enlarged

and/or have been reduced in size.

N2021/27200-AT-00

23

Reference List

electric machine rotor axis of rotation

rotor

coolant

Conveying and distribution device

first axial front end second axial front end disk pack rotor shaft

Rotor lamella partial lamella package receiving channel permanent magnet coolant inlet coolant outlet open flow gradient flow edge

ring canal

ring plane

first pressing element metal ring cooling liquid duct feed opening outer housing gear output shaft hollow shaft reduction gear drive unit

lateral surface

24/40

30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

R1 R2 R3 AR Vehicle

Second pressure element Pressure disk Pressure disk Threaded nut Threaded nut Coolant collection channel Coolant collection ring Stator Drainage opening Coolant reservoir Oil sump

breakthrough material removal balancing hole connecting channel connecting channel

Impact or deflection surface

larger radial distance smaller radial distance largest radius

radial difference centrifugal force

N2021/27200-A T-00

Claims (20)

patent claims 1. Electrical machine (1) with a cooling liquid (4) coolable rotor (3), comprising - a rotor shaft (9) with a rotor axis of rotation (2), - a lamella pack (8) mounted non-rotatably on the rotor shaft (9) and consisting of a plurality of magnetizable rotor lamellae (10) lined up along the rotor axis of rotation (2), characterized in that at least one axial front end (6, 7) of the disk pack (8) has a conveying and distribution device (5) using centrifugal forces for the coolant to be supplied to the disk pack (8), which conveying and distribution device (5) has at least one coolant inlet (14) and at least one cooling liquid outlet (15), wherein a radial distance (R1) of the at least one cooling liquid outlet (15) relative to the rotor axis of rotation (2) is greater than a radial distance (R2) of the at least at least one cooling liquid inlet (14) relative to the rotor axis of rotation (2). 2. Electrical machine according to claim 1, characterized in that the conveying and distribution device (5) using centrifugal forces is non-rotatably connected to the rotor shaft (9) and/or the disk pack (8) and is set up to reduce the pressure of the cooling liquid at the cooling liquid process (15) against above the pressure of the coolant at the coolant inlet (14). 3. Electrical machine according to claim 1 or 2, characterized in that the cooling liquid inlet (14) is provided for cooling liquid exclusively under the action of gravity or with ambient pressure of the conveying and supply distribution device (5). N2021/27200-AT-00 4. Electrical machine according to one of the preceding claims, characterized in that a first pressing element (20) for applying an axial pressing force relative to the first axial end face (6) of the Lamel- lenpakets (8) is formed. 5. Electrical machine according to one of the preceding claims, characterized in that a second pressing element (30) for applying an axial pressing force relative to the second axial end face (7) of the load mells package (8) is formed. 6. Electrical machine according to one of the preceding claims, characterized in that a plurality of cooling liquid channels (22) distributed over the circular cross section of the rotor (3) is formed, which pass through the disk pack (8) in the axial direction of the rotor (3), and that the conveying and distribution device (5) is set up to supply cooling to transfer liquid into this plurality of cooling liquid channels (22). 7. Electrical machine according to one of claims 4 to 6, characterized in that the conveying and distribution device (5) comprises an annular channel (18) in or on the first pressing element (20), and that the cooling liquid channels (22) in the disk pack (8) fluidically coupled to the ring channel (18). are. 8. Electrical machine according to claim 7, that the annular channel (18) has the cooling liquid inlet (14) lying radially on the inside and lying radially further on the outside near the at least one cooling liquid outlet (15). 9. Electrical machine according to one of the preceding claims, characterized in that the cooling liquid inlet (14) in the radial direction outwardly at a distance from an outer lateral surface (29) of the rotor shaft (9) decorated. N2021/27200-AT-00 10. Electrical machine according to one of the preceding claims, characterized in that the radial distance (R2) of the at least one cooling liquid inlet (14) relative to the rotor axis of rotation (2) is dimensioned larger than the largest radius (R3) of the rotor shaft (9). 11. Electrical machine according to one of the preceding claims, characterized in that the rotor shaft (9) is designed as a hollow shaft (26), which hollow shaft (26) can be pushed through centrally by an output shaft (25) of a reduction gear (27), and which reduction gear ( 27) input is rotationally connected to the rotor shaft (9) on the side. 12. Electrical machine according to one of claims 7 to 11, characterized in that the annular channel (18) is delimited at least in sections by a cross-section essentially L-shaped or U-shaped metal ring (21), which metal ring (21) on an axially outer Face of the first pressing element (20) is fixed, in particular by means of a press fit with the first pressing ck element (20) is connected. 13. Electrical machine according to one of the preceding claims, characterized in that the second axial front end (7) of the rotor (3) or the disk pack (8) is assigned an annular cooling liquid collecting channel (35), the center point of which lies on the rotor axis of rotation (2) and therefore sen ring plane transverse to the rotor axis of rotation (2). 14. Electrical machine according to claim 13, characterized in that the coolant-collecting channel (35) comprises a coolant-collecting ring (36) which is rigidly connected to an outer housing (24) or to a stator (37) of the electrical machine (1). is and for the cumulative intake of cooling liquid channels (22) of the disk pack (8) emerging Coolant is provided. N2021/27200-AT-00 15. Electrical machine according to claim 13 or 14, characterized in that the coolant collection channel (35) and/or the coolant collection ring (36) has a discharge opening (38) for accumulated coolant at its lowest point in the vertical direction or lower section, which discharge opening ( 38) is provided for the fluidic connection of the cooling liquid collecting channel (35) with a cooling liquid reservoir (39), in particular for the fluidic connection with an oil sump (40) in a reduction gear (27) connected downstream of the electrical machine (1). is. 16. Electrical machine according to one of claims 6 to 15, characterized in that the cooling liquid channels (22) in the disk pack (8) achspa- run parallel to the rotor axis of rotation (2). 17. Electrical machine according to one of claims 6 to 16, characterized in that the cooling liquid channels (22) in the disk pack (8) are formed by fluidly communicating openings (41) in a plurality of individual disk part packages (11), which disk partial packages (11) are lined up directly next to one another along the rotor axis of rotation (2). 18. Electrical machine according to one of claims 4 to 17, characterized in that the first pressing element (20) on the first axial front end (6) and the second pressing element (30) on the second axial front end (7) of the lamina lenpakets (8) are structurally and geometrically identical. 19. Electrical machine according to one of claims 4 to 18, characterized in that the first and/or the second pressing element (20, 30) is provided for applying material removals (42) for balancing the rotor (3), in particular for applying balancing bores (43) see is. N2021/27200-AT-00 20. Drive unit (28) for an electric vehicle, comprising an electric machine (1) and a reduction gear (27) connected downstream of the electric machine, characterized in that the electric machine (1) according to a NEM of the preceding claims is formed. 29 / 40 N2021/27200-AT-00