Electric drive arrangement with cooling

Abstract

Electric drive arrangement for driving a motor vehicle, comprising: a multi-part housing (5), an electrical machine (3) with a stator (12) and a rotor (13), wherein the stator (12) is accommodated in the housing (5) in a rotationally fixed manner and has a stator core (15) and windings (16), the winding heads (17, 18) of which project axially beyond the stator core (15) on both sides, wherein the rotor (13) is connected to a rotor shaft (14) which is mounted in the housing (5) for rotation about an axis of rotation (A3), a gear (4) which is rotatably driven by the rotor shaft (14) and is designed to translate a rotary movement initiated by the electric machine (3) from fast to slow, at least one fluid distribution element (24, 25) for supplying coolant (K) to one of the winding heads (17, 18) by utilizing gravity, wherein the fluid distribution element (24, 25) at least partially covers an upper part of the winding head (17, 18) in the circumferential direction and in the axial direction and has a guide structure with a gradient in the circumferential direction, so that coolant supplied to the fluid distribution element (24, 25) from above is distributed in the circumferential direction and runs in several angular positions over a circumferential range of at least 30° with respect to the axis of rotation (A3) onto the winding head (17, 18), wherein the fluid distribution element (24, 25) has a variable circumferential extent (C24, C25) over its axial length (L24, L25), so that a distribution section (28, 28'; 29, 29') axially adjacent to the stator core (15) has a different circumferential extent than axially remote from the stator core (15).

Description

[0001] The invention relates to an electric drive arrangement with an electric machine and transmission for driving a motor vehicle.

[0002] A key issue in electric drive systems is thermal behavior. Both the electric motor and the transmission generate heat that must be dissipated to avoid excessively high temperatures and thus ensure a long service life. The electric drive system must be able to withstand various driving conditions over the long term. This also applies to special driving situations, such as long inclines with operating angles typical for off-road vehicles, as well as high-speed driving situations.

[0003] Supplying all rotating components of a gearbox with lubricant is often a challenge. A sufficient oil level must be maintained to ensure good lubrication and cooling of shafts and bearings. At the same time, splashing losses during operation must be prevented.

[0004] WO 2019 / 091351 A1 discloses an electric drive assembly comprising an electric machine and a transmission. The electric machine includes a motor controller with a built-in water cooling mechanism, which is designed as a heat exchanger for the electric motor. Furthermore, an oil cooling mechanism is provided with an oil channel in the upper region of an inner wall of the housing, an opening to a stator slot that extends axially and is open in the upper region of the end winding, and an oil sprinkler into which the stator slot opens.

[0005] WO 2019 / 184580 A1 discloses a liquid-cooled drive motor in which the hollow rotor shaft is supplied with cooling fluid via a fluid inlet, and the stator is cooled via a stator fluid channel. The stator fluid channel is arranged on the stator core and supplies the underlying end windings with cooling fluid at the axial ends, which flows through openings in the housing. A stator cooling ring is arranged axially between the stator core and the stator windings at each end.

[0006] From DE 102019 113 091 A1, an annular guide device for cooling fluid flowing around a winding head of an electrical machine is known.

[0007] WO 2012 / 086694 A1 discloses a drive unit comprising an electric machine, an inverter, a transmission arrangement, and a cooling system. A first housing element, thermally coupled to the inverter, has a first set of heat exchange surfaces, and a second housing element, thermally coupled to the electric machine, has a second set of heat exchange surfaces. The first and second sets of heat exchange surfaces each project into an internal volume cooled by a coolant. The transmission has a raised oil sump supplied by the same oil pump that circulates the oil in the electric machine, with the raised oil sump supplying selected surfaces within the transmission with oil by gravity.

[0008] WO 2020 / 069 744 A1 discloses an electric drive for driving a motor vehicle, comprising a housing arrangement, an electric machine, a planetary unit, and a power split unit. The housing arrangement comprises an engine housing part, a transmission housing part, and an intermediate housing part with an intermediate wall that spatially separates the engine compartment and the transmission compartment. The intermediate housing part has a motor-side shell section that extends into the engine housing part, and a transmission-side shell section that extends into the transmission housing part. A sealed cavity for a flowing coolant is formed between the outer surface of the motor-side shell section and the inner surface of the engine housing part.

[0009] An electric drive unit for driving a motor vehicle is known from US 11 005 326 B2. The drive unit comprises a housing with a bottom portion that divides the housing into an upper and a lower chamber. The bottom portion has an elongated drain opening, drain holes, and an oil feed opening that communicates with an oil pump. Located in the lower chamber is an electric machine with electrical leads arranged directly below the drain opening. A cover is attached to the housing at the upper chamber, which cover has a cooling channel arrangement that is integrally connected to a cover plate. The cooling channel arrangement forms a primary coolant channel that communicates with the oil feed opening and conducts oil to the electrical terminals.

[0010] The present invention is based on the object of proposing an electric drive with an electric machine and gear unit, which ensures reliable cooling of the stator even in a small installation space and thus has a high efficiency and a long service life.

[0011] According to a first solution, an electric drive for driving a motor vehicle is proposed, comprising, as essential to the invention: a multi-part housing, an electric machine with a stator and a rotor, wherein the stator is accommodated in the housing in a rotationally fixed manner and has a stator core and windings whose winding heads project axially beyond the stator core on both sides, wherein the rotor is connected to a rotor shaft which is rotatably mounted in the housing about an axis of rotation, a gear which is rotatably driven by the rotor shaft, at least one fluid distribution element for distributing coolant via one of the winding heads, wherein the fluid distribution element at least partially covers an upper section of the winding head in the circumferential direction and in the axial direction and has a guide structure with a gradient in the circumferential direction,so that coolant supplied to the fluid distribution element can be distributed in the circumferential direction and flow onto the winding head in several angular positions over a circumferential range of at least 30° with respect to the axis of rotation, wherein the fluid distribution element has a variable circumferential extent over its axial length, so that a distribution section axially adjacent to the stator core has a different circumferential extent than axially remote from the stator core.

[0012] According to a second solution, an electric drive for driving a motor vehicle is proposed, comprising, as essential to the invention: a multi-part housing, an electric machine with a stator and a rotor, wherein the stator is accommodated in the housing in a rotationally fixed manner and has a stator core and windings whose winding heads project axially beyond the stator core on both sides, wherein the rotor is connected to a rotor shaft which is rotatably mounted in the housing about an axis of rotation, a gear which is rotatably driven by the rotor shaft, at least one fluid distribution element for distributing coolant via one of the winding heads, wherein the fluid distribution element at least partially covers an upper section of the winding head in the circumferential direction and in the axial direction and has a guide structure with a gradient in the circumferential direction,so that coolant supplied to the fluid distribution element can be distributed in the circumferential direction and flow onto the winding head in several angular positions over a circumferential range of at least 30° with respect to the axis of rotation, wherein a reservoir is provided within the housing, separate from the motor housing space and the gearbox housing space, into which reservoir coolant is conveyed during operation and in which a suction opening for the pump is arranged, wherein the coolant level in the reservoir is above the coolant level of the motor housing space and / or the gearbox housing space during operation.

[0013] Electrical machines and / or transmissions are typically cooled or lubricated with a coolant. A fluid, in particular an oil or an oil-containing liquid, is preferably used as the coolant. Where the term "oil" is used alone or in combination within the scope of this disclosure, this is intended to include any form of coolant.

[0014] One advantage of an electric drive according to the invention is that, thanks to the fluid distribution element, it ensures reliable lubrication for an associated winding head. Cooling is thus achieved in a space-saving and efficient manner by utilizing gravity. Active lubrication of the winding head using nozzles or spray heads is not necessary, so that the required installation space is small. Depending on the specific requirements of the overall cooling concept, one or both of the winding heads can be provided with an associated fluid distribution element. Accordingly, all features described below for a fluid distribution element also apply analogously to a further fluid distribution element, which can be provided for cooling the other winding head.

[0015] A fluid distribution element can be arranged axially in the housing between the stator core and an opposite housing wall. During operation, the fluid distribution element is supplied with coolant from a supply in the housing. When installed, the outlet of the supply is preferably located vertically above the distribution element, so that the coolant flows onto the fluid distribution element by gravity. The fluid distribution element is designed so that coolant flowing from the supply is distributed over an angular segment of at least 30° of the winding head and flows onto the winding head.

[0016] A fluid distribution element can extend over or cover at least half the axial length of the winding head, in particular at least two-thirds or even the entire axial length of the winding head. In this way, a correspondingly large axial section of the winding head is supplied with cooling oil and cooled.

[0017] According to one embodiment, the fluid distribution element can have a collecting section, which is supplied with oil from the oil supply during operation, and one or more distribution sections that are fluidly connected to the collecting section and distribute oil flowing from the collecting section in the circumferential direction and / or in the longitudinal direction. The collecting section can optionally have one or more radial passage openings through which the radially underlying circumferential section of the winding head can be cooled with oil.

[0018] In further detail, the collecting section can be arranged centrally, from which a distribution section can extend in both circumferential directions. Overflow openings can be formed between the collecting section and the distribution sections, so that oil in the collecting section is directed through the overflows into the distribution sections. A distribution section can have one or more channels extending from the collecting section in the circumferential direction. At the end of the channels, the oil flows onto the winding head located below or radially inside.

[0019] A particularly large cooling surface is covered if the fluid distribution element has a variable circumferential extension over its axial length. Accordingly, a distribution section axially adjacent to the stator core has a different circumferential length than the one axially distant from the stator core. In one embodiment, a distribution section can have several circumferentially extending channels of different lengths. In this way, a correspondingly large circumferential segment of the winding head is supplied with cooling oil. In an embodiment in which both winding heads are provided with a respective oil distribution element for cooling, the two elements can expand in the same or opposite axial direction.

[0020] According to one embodiment, a fluid distribution element can be configured with fastening means such that it can be axially mounted in the housing. For this purpose, the fluid distribution element can have a plurality of fastening sections with which it is non-positively and / or positively fastened to corresponding, opposing holding sections in the housing. In a specific embodiment, the fluid distribution element can axially span the axial gap between a side surface of the stator core and the opposite housing wall and / or be axially supported against a side surface of the stator core. The fluid distribution element, which can also be referred to as an insert for coolant distribution, can be made of plastic or sheet metal, for example.

[0021] The oil supply and the oil distribution element for stator cooling are part of a cooling circuit or cooling arrangement of the electric drive. The cooling arrangement can have an oil sump, additional cooling channels, and conveying means to transport and circulate coolant to required components for heat dissipation and lubrication. The cooling and circulation of the coolant in the electric drive can be designed actively and / or passively. With passive cooling, the coolant is conveyed by rotating components of the electric drive and circulates using gravity. With active cooling, the coolant is conveyed and circulated by a pump. Mixed cooling can be designed so that coolant is conveyed both actively by a pump and passively by rotating components.

[0022] According to one embodiment, the cooling arrangement can be designed such that at least 10% of the circulating coolant is delivered to the oil distribution element. This can apply to active and / or passive cooling. If the electric drive has only one oil distribution element, at least 10%, in particular at least 15%, of the coolant is delivered to the oil distribution element. If both winding heads are cooled by means of a respective oil distribution element, then a total of at least 20%, in particular at least 25%, of the cooling volume flow can be used to cool the winding heads. This total cooling flow for the winding heads can be divided equally between each winding head.

[0023] A gap is formed between the stator and the rotor of the electric machine. The cooling arrangement is preferably designed such that the static and / or dynamic oil level in the housing is below the gap. To prevent oil from entering the working gap of the electric machine and to minimize gear splash losses, a low oil level in the motor or gear housing chamber is preferably aimed for. In one embodiment, a reservoir separate from the motor housing chamber and the gear housing chamber can be provided within the housing. The reservoir, which can also be referred to as a tank, can be arranged, for example, laterally adjacent to the electric motor.

[0024] A design with a reservoir is particularly advantageous when combined with active cooling with a pump. The reservoir forms a tank volume for active lubrication in the central housing, which is separate from the electric motor and / or the gearbox compartment and has its own oil level during operation. In order to maintain the separate coolant levels constantly during operation, the volume flow pumped from the tank by the hydraulic pump must also be pumped back into the tank. This can be achieved by suitable return of pressurized volume flows directly into the tank and / or by pressureless volume flows using suitable pumping mechanisms for the rotating components.

[0025] The reservoir is arranged or designed in such a way that during operation oil is pumped into the reservoir by means of a rotating component. An oil guide structure can be provided in the housing to collect oil thrown off by the rotating component and guide it into the reservoir. A suction opening for the pump can be arranged in the reservoir. During operation the oil level in the reservoir is above the oil level in the engine housing chamber and / or transmission housing chamber. This raised oil level above the suction point ensures reliable suction or supply to the hydraulic lubrication system even under dynamic driving conditions such as lean angles and lateral acceleration. The reservoir can be formed by a side wall and a circumferential, flange-like wall that is closed by a cover.The cover may include a filter element for filtering the oil and a downstream connecting element for fluid communication with the intake port. The reservoir cover may further include an oil collecting rib configured to direct oil delivered by the pump via an oil inlet into the housing to a gearing area of ​​the transmission.

[0026] The described design with a reservoir and intake in the reservoir is particularly suitable for arrangements where, due to space constraints, the intake of the active lubrication system does not allow a significant height difference to the rotating components of the electric motor and / or transmission. Here, the reservoir offers a way to meet the requirements regarding the working gap of the electric motor and unwanted splashing losses on the one hand, and the robust intake in the lubrication system on the other, with a common oil supply.

[0027] The electric machine can be controlled using power electronics, such as a pulse-controlled inverter with an integrated electronic control unit (ECU). The power electronics, which can also be referred to as an inverter, can be part of the electric drive. For this purpose, the housing can have a connecting flange for connecting the inverter. Overall, this creates a motor-gearbox-inverter unit. The electric machine can be powered by a battery. The power electronics are functionally located between the battery and the electric machine. An inverter controls and monitors the electric machine and ensures that the torque and speed of the drive train are supplied as needed. When the electric machine is operating in motor mode, the inverter supplies the electric motor with power from the battery.When the electric motor is operating in generator mode, the inverter feeds power into the battery. During this process, known as recuperation, the inverter converts the alternating current (AC) generated by the electric motor into direct current (DC), thus charging the battery. When the motor is operating, the inverter converts the battery's DC voltage into the AC voltage required by the electric motor.

[0028] A preferred embodiment is explained below with reference to the drawing figures. Herein: Fig. 1 shows an electric drive arrangement according to the invention with an electric machine and transmission, with a partially sectioned housing; Fig. 2 the electric machine Fig. 1 in perspective exploded view; Fig. 3 the electric machine Fig. 1 and Fig. 2 in perspective view, with partially cut-out housing; Fig. 4 the electric machine Fig. 1 and Fig. 2 with cooling channels shown and the rest of the housing cut away; Fig. 5 the electric machine Fig. 1 and Fig. 2 as a detail with fluid distribution elements in radial view; Fig. 6 a first fluid distribution element of the electric drive from Fig. 1 in a perspective view from the front; Fig. 7 a second fluid distribution element of the electric drive from Fig. 1 in a perspective view from the rear; Fig. 8A the gearbox of the electric drive assembly Fig. 1 in axial view; Fig. 8B part of the gearbox Fig. 8A in perspective view; Fig. 8C the arrangement of Fig. 8B without cover in axial view; Fig. 8D the gearbox housing Fig. 8C with lid according to section line CC in perspective view; Fig. 9A the cover of the gearbox Fig. 8A in a perspective view from the front; and Fig. 9B the cover of the gearbox Fig. 8A in a perspective view from behind.

[0029] The Fig. 1 to 9B are described together below. An electric drive arrangement 2 according to the invention is shown, which can also be referred to as an electric drive for short. The electric drive arrangement 2 comprises an electric machine 3 and a transmission 4, which is drivingly connected to the electric machine 3. The transmission 4 translates a rotary movement initiated by the electric machine 3, in particular into slow speed, and can transmit this to a downstream sideshaft of the motor vehicle (not shown). The electric machine 3 and the transmission 4 are accommodated in a housing arrangement 5, which can also be referred to as a housing for short.

[0030] The electric machine 3 serves as a drive source for driving a drive axle of a motor vehicle. The electric machine 3 can be controlled by means of power electronics, such as a pulse-controlled inverter with an integrated electronic control unit (ECU). The electrical connection to the power electronics is established via an electrical connection 48. The power electronics (not shown) can optionally be attached to a connecting section 6 of the housing assembly 5. For power supply, the electric machine 3 must be connected to a battery (not shown).

[0031] The housing can in particular be designed in several parts and comprise a motor housing part 7 and a gear housing part 8, which can be connected to one another, for example, via a flange connection 9.

[0032] The electric machine 3 has a stator 12, which is fixedly connected to the housing 8, and a rotor 13, which is fixedly connected to a rotor shaft 14 for torque transmission. The rotor shaft 14 is rotatably mounted in the motor housing about a rotation axis A3. The electric machine 3 can be designed as an asynchronous machine or synchronous machine. The stator 12 has a stator core 15 and windings 16, the winding overhangs 17, 18 of which project axially beyond the stator core on both sides. The stator core 15 can comprise an electrical sheet stack, which optionally has circumferentially distributed through holes 19 and can be axially clamped to the housing by means of clamping screws 20.

[0033] The present electric drive assembly 2 has a special design with regard to the cooling of the electric machine 3. For this purpose, the assembly has a cooling system for each winding head 17, 18 with a coolant supply 22, 23 in the housing 5 and an associated fluid distribution element 24, 25 that distributes the supplied coolant over a larger area. A fluid, preferably an oil or an oil-containing liquid, is used as the coolant. The supplies 22, 23 and the fluid distribution elements 24, 25 for stator cooling are part of a cooling circuit of the electric drive.

[0034] In Fig. 4 further cooling lines 21, 21' can be seen, which lead to the feeds 22, 23, as well as cooling line 48, which leads to the cooling of the bearing 53.

[0035] The two fluid distribution elements 24, 25 are designed identically in terms of their structure and function. Only one of the two elements can be described as representative of both, with the described features also applying analogously to the other. The fluid distribution elements 24, 25 are arranged in the housing 5 above the winding heads 17, 18, or axially between the stator core 15 and a housing wall 26, 27 axially opposite it. The fluid distribution elements 24, 25 can be attached in any desired manner, for example, by form-fitting, force-fitting, and / or material-fitting.

[0036] The fluid distribution elements 24, 25 are designed and arranged such that they at least partially cover an upper section or segment of the winding head 17, 18 in the circumferential direction and in the axial direction. The fluid distribution elements 24, 25 distribute the coolant flowing in from the supply line 22, 23 with respect to the rotational axis A3 over an angular segment s of preferably at least 30° and / or over a length L24, L25 of at least half the axial length L17, L18 of the associated winding head 17, 18. The inflowing coolant is distributed solely by gravity; nozzles or the like are not required. In this way, a relatively large circumferential area of ​​the winding heads 17, 18 is effectively cooled without additional aids.

[0037] As can be seen in particular from the Fig. 6 and Fig. As can be seen from Figure 7, the fluid distribution elements 24, 25 can each have a collecting section 26, 27 and fluidically connected distribution sections 28, 28'; 29, 29'. During operation of the arrangement, coolant flows from the oil supply 22, 23 into the associated collecting section 26, 27, from where it flows to the distribution sections and is distributed over a larger area due to gravity and then flows onto the winding heads 17, 18.

[0038] The collecting sections 26, 27 can optionally have a radial passage opening 32, 33 through which a portion of the supplied coolant can flow directly to cool the radially underlying section of the winding overhang 17, 18 and cool it. The collecting section 26, 27 is arranged centrally here, but is not limited thereto. A distribution section 28, 28'; 29, 29' extends circumferentially on both sides of the collecting section 26, 27. The distribution sections each have a plurality of channels 30, 31 that extend circumferentially from the collecting section and each have an open end, from where the coolant flows to the radially underlying winding overhang 17, 18. Overflow openings 34, 35 can optionally be formed between the collecting section 26, 27 and the distribution sections 28, 28'; 29, 29'.The overflow openings facilitate a targeted coolant supply into all channels 30, 31, so that uniform cooling is achieved via the winding heads 17, 18 below.

[0039] In the present embodiment, the fluid distribution elements 24, 25 each have a variable circumferential extent U24, U25 over their axial length L24, L25, although other designs with the same circumferential extent are also possible. Fig. 5 that the distribution sections 28, 28'; 29, 29' have a different circumferential length axially adjacent to the stator core 12 than axially distant from the stator core. In particular, the fluid distribution elements 24, 25 are approximately V-shaped when viewed radially. Due to the V-shaped design, the channels 30, 31 have different circumferential lengths. In this way, a correspondingly large circumferential segment of the respective winding head 17, 18 is supplied with cooling oil. In the present embodiment, both fluid distribution elements 24, 25 expand in the same axial direction Ra. The circumferential extent (circumferential angle s) of the fluid distribution elements 24, 25 can, for example, be between 30° and 180° with respect to the axis of rotation A3.

[0040] The fluid distribution elements 24, 25 each have fastening means 36, 37, 38, 39 with which they are axially fastened in the housing 5. In particular, it is provided that the fluid distribution element 24 has a fastening element 36 on the short side in the circumferential direction and several fastening elements 37 on the long circumferential side. The fastening elements 36, 37 are designed such that they can engage with correspondingly opposing holding sections 41, 42 in the housing 5 in a force-fitting and / or form-fitting manner. Preferably, the fluid distribution element 24 is axially supported against the side surface of the stator core 15 and spans the axial space between the stator core and the opposite housing wall. The second fluid distribution element 25, which can be supported with its short end on the opposite side of the stator, is axially fixed between the motor housing 45 and the intermediate wall 45 by means of the fastening elements 38, 39.For this purpose, the motor housing 45 and the intermediate wall 45 have opposing retaining sections 43, 44, which can be designed in the form of holes. The fluid distribution elements 24, 25 can be made of plastic or sheet metal.

[0041] During operation, the coolant K flows over the winding heads 14, 15 and reaches the oil sump S5 of the housing 5. From here, the coolant K is circulated again, whereby the cooling system has conveying means and further cooling channels in order to transport and circulate the coolant K to the required components for heat dissipation and lubrication. The cooling system is preferably designed such that at least 20% of the circulating coolant K is conveyed to the two fluid distribution elements 24, 25, i.e. at least 10% per fluid distribution element. The remaining circulating coolant flow is distributed in particular to supply the bearings and seals, the stator core 15, the rotor 13 and optionally one or more gear pairs. A heat exchanger is preferably arranged in the flow path behind the pump in order to cool down the heated oil in the return flow.

[0042] In the Fig. 8A to 8D, together also known as Fig. 8, the gearbox 4 is shown. The multi-part housing 5 comprises a gearbox housing space 40, in which the gearbox 4 is accommodated, and a motor housing space 50, in which the electric machine 3 is accommodated. The gearbox housing 8 has a connecting flange 57, which is to be connected to the opposite connecting flange 56 of the motor housing 7. The gearbox 4 is designed as a gear train and comprises several meshing pairs of gears. It is understood that the gearbox and housing can be designed according to technical requirements, such as the torque to be transmitted, speeds, and installation space, and can therefore also have designs other than those shown here.

[0043] In the present embodiment, the transmission 4 comprises a first pair of gears with a pinion connected to the rotor shaft 14 and a gear 52 meshing therewith. In the assembled state, the rotor shaft 14 is rotatably mounted at its end by means of the bearing 53 in the bearing seat 54 of the intermediate wall 45 about the axis of rotation A3. A second pair of gears comprises an intermediate gear connected in a rotationally fixed manner to the gear 52 via an intermediate shaft and a gear 55, which can also be referred to as an output gear. The intermediate shaft is rotatably mounted about the axis of rotation A52 by means of a bearing 51 in the bearing seat 60 of the intermediate wall 45. The gear 55 is rotatably mounted about the axis of rotation A55 by means of a bearing 70 in the bearing seat 71 of the motor housing 7. Preferably, the axis of rotation A55 of the output gear lies slightly below, and the axis of rotation A52 of the intermediate shaft lies slightly above, the axis of rotation A3 of the electric machine 3.

[0044] A further special feature of the present electric drive arrangement 2 is that it includes both active and passive coolant delivery, without being limited thereto. Passive coolant delivery is formed by a rotating component, in particular a gear wheel, which delivers coolant from the oil sump S5 into a separate reservoir 49. Furthermore, a hydraulic pump (not shown) is provided, the suction side of which lies in the reservoir 49, from which the pump recirculates the coolant. Located on the transmission housing 8 are the suction-side hydraulic connection 46 to the pump, and the pressure-side hydraulic connection 47 back into the cooling system.

[0045] A gap 11 is formed between the stator 12 and the rotor 13 of the electric machine 3. The cooling arrangement is designed in particular such that the oil level P5 in the motor housing 7 and / or in the transmission housing 8 is below the gap 11 of the electric machine during operation. A reservoir 49 is provided within the housing 5, separate from the motor housing space 50 and the transmission housing space 30. The reservoir 49 is arranged axially in a connecting region between the transmission housing and the motor housing, in particular axially adjacent to the electric machine 3.

[0046] Reservoir 49 forms a separate tank volume within housing 5 for active lubrication. The reservoir is separated from the engine compartment and transmission compartment and has its own oil level P49 during operation. To maintain the separate coolant levels P5 and P49 during operation, the volume flow pumped from the tank volume by the hydraulic pump must also be pumped back into the tank. This can be achieved by suitable return of pressurized volume flows directly into the tank and / or by pressureless volume flows using suitable pumping mechanisms for the rotating components.

[0047] It is particularly in Fig. 8C that the reservoir 49 is arranged or designed such that, during operation, coolant K is pumped into the reservoir 49 by means of the rotating gear 52. An oil guide structure 58, 59 is provided in the housing 5 to collect oil thrown off by the gear 52 and guide it into the reservoir. The rotational movement of the gear 55 is designated R55, and the flow direction of the coolant K is designated F. The intake opening 61 for the pump is arranged in the reservoir 49. During operation, the oil level P49 in the reservoir is above the oil level P5 in the engine housing chamber and / or transmission housing chamber. The oil level P49 being above the intake point ensures reliable intake and supply of coolant to the hydraulic lubrication system, even under dynamic driving conditions.

[0048] The reservoir 49 is formed by the side wall 62 of the gear housing 8, a circumferential, flange-like wall 63 and a cover 64, which is shown as a detail in the Fig. 9A and Fig. 9B. The cover 64 comprises a filter element 65 for filtering the oil before the return flow and a downstream connecting element 66 for fluidic connection to the intake opening 61. The cover further comprises an oil collecting rib 67, which is designed to guide oil delivered by the pump via an oil inlet channel 68, 68' into the housing 5 to a toothed area of ​​the gear 52 with the drive pinion.

[0049] The electric machine 3 can be controlled by means of power electronics (not shown). The power electronics can be connected to the housing 5 via the connecting flange 69. The power supply to the electric machine 3 can be provided by a battery. List of reference symbols 2 Electric drive arrangement 3 electric machine 4 gearboxes 5 housings 6 connecting section 7 Motor housing part 8 Gearbox housing part 9 Flange connection 12 Stator 13 Rotor 14 Rotor shaft 15 Stator core 16 windings 17 winding head 18 winding head 19 Through hole 21, 21' line 22 Feed 23 Feed 24 Fluid distribution element 25 Fluid distribution element 26 Collection section 27 Collection section 28, 28' distribution section 29, 29' distribution section 30 channels 31 channel 32 passage opening 33 Passage opening 34, 34' overflow mouth 35, 35' overflow mouth 36, 37 Fasteners 38, 39 Fasteners 40 Gearbox housing compartment 41 stopping section 42 stopping section 43 stopping section 44 stopping section 45 Partition wall 46 hydraulic connection 47 hydraulic connection 48 electrical connection 49 Reservoir 50 engine housing compartment 51 warehouses 52 gear 53 warehouses 54 bearing seat 55 gear 56 Connecting flange 57 Connecting flange 58 Oil conducting structure 59 Oil conducting structure 60 bearing seat 61 Intake port 62 side wall 63 wall 64 lids 65 filter element 66 connecting element 67 Oil collecting rib 68, 68' oil inlet channel 69 connecting flange 70 warehouses 71 bearing seat A axis of rotation F Flow direction K Coolant L length P dynamic coolant level R direction S coolant sump s angular range U circumferential extent

Claims

[1] Electric drive arrangement for driving a motor vehicle, comprising: a multi-part housing (5), an electrical machine (3) with a stator (12) and a rotor (13), wherein the stator (12) is accommodated in the housing (5) in a rotationally fixed manner and has a stator core (15) and windings (16), the winding heads (17, 18) of which project axially beyond the stator core (15) on both sides, wherein the rotor (13) is connected to a rotor shaft (14) which is mounted in the housing (5) for rotation about an axis of rotation (A3), a gear (4) which is rotatably driven by the rotor shaft (14) and is designed to translate a rotary movement initiated by the electric machine (3) from fast to slow, at least one fluid distribution element (24, 25) for supplying coolant (K) to one of the winding heads (17, 18) by utilizing gravity, wherein the fluid distribution element (24, 25) at least partially covers an upper part of the winding head (17, 18) in the circumferential direction and in the axial direction and has a guide structure with a gradient in the circumferential direction, so that coolant supplied to the fluid distribution element (24, 25) from above is distributed in the circumferential direction and runs in several angular positions over a circumferential range of at least 30° with respect to the axis of rotation (A3) onto the winding head (17, 18), wherein the fluid distribution element (24, 25) has a variable circumferential extent (C24, C25) over its axial length (L24, L25), so that a distribution section (28, 28'; 29, 29') axially adjacent to the stator core (15) has a different circumferential extent than axially remote from the stator core (15). [2] Electric drive arrangement for driving a motor vehicle, comprising: a multi-part housing (5), an electrical machine (3) with a stator (12) and a rotor (13), wherein the stator (12) is accommodated in the housing (5) in a rotationally fixed manner and has a stator core (15) and windings (16), the winding heads (17, 18) of which project axially beyond the stator core (15) on both sides, wherein the rotor (13) is connected to a rotor shaft (14) which is mounted in the housing (5) for rotation about an axis of rotation (A3), a gear (4) which is rotatably driven by the rotor shaft (14) and is designed to translate a rotary movement initiated by the electric machine (3) from fast to slow, at least one fluid distribution element (24, 25) for supplying coolant (K) to one of the winding heads (17, 18) by utilizing gravity, wherein the fluid distribution element (24, 25) at least partially covers an upper part of the winding head (17, 18) in the circumferential direction and in the axial direction and has a guide structure with a gradient in the circumferential direction, so that coolant supplied to the fluid distribution element (24, 25) from above is distributed in the circumferential direction and runs in several angular positions over a circumferential range of at least 30° with respect to the axis of rotation (A3) onto the winding head (17, 18), wherein a reservoir (49) is provided within the housing (5) which is separate from the motor housing space (50) and the transmission housing space (40), into which reservoir coolant is conveyed during operation and in which a suction opening (61) for the pump is arranged, wherein the coolant level (P49) in the reservoir (49) is above the coolant level (P5) of the motor housing space (50) and / or the transmission housing space (40) during operation. [3] Electric drive arrangement according to claim 1 or 2, characterized bythat a supply line (22, 23) is provided in the housing (5), via which the fluid distribution element (24, 25) is supplied with coolant during operation, wherein the fluid distribution element (24, 25) is arranged in particular at a distance vertically below the supply line (22, 23). [4] Electric drive arrangement according to one of claims 1 to 3, characterized by that the fluid distribution element (24, 25) extends over at least half the axial length of the winding head (17, 18). [5] Electric drive arrangement according to one of claims 1 to 4, characterized by that the fluid distribution element (24, 25) has a collecting section (26, 27) which, during operation, is fed with coolant from the supply (22, 23), and distribution sections (28, 28'; 29, 29') which are fluidically connected to the collecting section (26, 27) and distribute coolant flowing from the collecting section (26, 27) in the circumferential direction (U). [6] Electric drive arrangement according to claim 5, characterized bythat the collecting section (26, 27) has at least one radial passage opening (32, 33). [7] Electric drive arrangement according to claim 1, characterized by that a distribution section (28, 28'; 29, 29') has a plurality of channels (30, 31) of different lengths extending in the circumferential direction (Ru). [8] Electric drive arrangement according to one of claims 1 to 7, characterized by that the fluid distribution element (24, 25) is mounted axially in the housing (5) and in particular has positive fastening means (36, 37, 38, 39) with which the fluid distribution element (24, 25) is fastened in the housing (5). [9] Electric drive arrangement according to one of claims 1 to 8, characterized by that a fluid distribution element (24, 25) is arranged on each of the two winding heads (17, 18) of the stator (12), wherein the two fluid distribution elements (24, 25) expand in the circumferential direction, in particular in the same axial direction (Ra). [10] Electric drive arrangement according to one of claims 1 to 9, characterized by that the fluid distribution element (24, 25) for stator cooling is part of a cooling arrangement with a coolant sump (S5) and a pump. [11] Electric drive arrangement according to claim 10, characterized by that the cooling arrangement is designed such that at least 10% of the circulating coolant is conveyed to at least one fluid distribution element (24, 25). [12] Electric drive arrangement according to one of claims 1 to 11, characterized by that a gap (11) is formed between the stator (12) and the rotor (13), wherein the static and / or dynamic coolant level (P5) in the housing (5) is below the gap (11). [13] Electric drive arrangement according to claim 1, characterized bythat a reservoir (49) is provided within the housing (5) which is separate from the motor housing space (50) and the transmission housing space (40), into which reservoir coolant is conveyed during operation and in which a suction opening (61) for the pump is arranged, the coolant level (P49) in the reservoir (49) being above the coolant level (P5) of the motor housing space (50) and / or the transmission housing space (40) during operation. [14] Electric drive arrangement according to claim 13, characterized by that a fluid guide structure (58, 59) is provided in the housing (5), which is designed to collect coolant thrown off by a rotating component (55) of the electric drive during operation and to guide it into the reservoir (49). [15] Electric drive arrangement according to claim 13 or 14, characterized bythat the reservoir (49) is closed by a reservoir cover (64), wherein the reservoir cover (64) has a filter element (65) and a connecting element (66) which is connected to the intake opening (61). [16] Electric drive arrangement according to one of claims 13 to 15, characterized by that the reservoir cover (64) has a coolant collecting rib (67) which is designed to guide coolant (K) conveyed by the pump via an oil inlet into the housing (5) to a toothing region of the transmission (4).

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