DE102019117155A1 - Electric drive for a vehicle and vehicle with the electric drive - Google Patents

Abstract

Electric axles are predestined for the smallest vehicle spaces. Due to the power density achieved in this way, heat dissipation from the system is becoming increasingly important. It is an object of the invention to show a structural implementation of transmission oil cooling in an electric drive. This object is achieved by an electric drive 1 for a vehicle, with at least one electric motor 6 for generating a drive torque for the electric drive 1, with a supply device 8 for supplying the electric motor 6 with electrical energy, with a cooling circuit 11 for cooling the supply device 8 and / or for cooling the electric motor 6 with a coolant, with a supply housing area 5, wherein the supply device 8 is arranged in the supply housing area 5 and wherein the supply housing area 5 has a wall section 26, the wall section 26 having an inner cooling structure 18, the inner Cooling structure 18 is flowed with the coolant and / or forms a fluidic section in the cooling circuit 11, and with a heat conducting plate 19 to cover the inner cooling structure 18 and for thermal coupling to the supply device 8, the heat conducting plate via a cohesive Liquid connection 35 is connected to the wall section 26.

Description

The invention relates to an electric drive for a vehicle with the features of the preamble of claim 1 and a vehicle with the electric drive.

Electric axles are predestined for the smallest vehicle spaces. Due to the power density achieved in this way, heat dissipation from the system is becoming increasingly important. While the electric motor and power electronics are water-cooled in all relevant applications, the transmission is usually cooled by convection through the airstream flowing onto the outer surfaces of the housing. As a result, the achievable cooling performance is limited and the vehicle's drag coefficient is reduced.

The pamphlet DE 10 2018 130 124 , which probably constitutes the closest prior art, relates to an electromotive drive unit with an electric motor, wherein a heat exchange fluid can be conducted through a housing of the electric motor, a heat exchanger being connected so that the heat exchange fluid can flow through it.

It is an object of the invention to show a constructive implementation of cooling in an electric drive. This object is achieved by an electric drive with the features of claim 1 and by a vehicle with the electric drive with the features of claim 9.

Preferred or advantageous embodiments of the invention emerge from the subclaims, the following description and the attached figures.

The invention relates to an electric drive which is suitable and / or designed for a vehicle. The vehicle can in particular be a passenger car, truck or bus. Alternatively, the vehicle is designed as a two-wheeler or a three-wheeler. The vehicle is implemented as a hybrid vehicle or as a purely electric vehicle. The electric drive preferably provides a main drive torque for the vehicle in order to move the vehicle in traffic.

The electric drive has at least or precisely one electric motor for generating a drive torque for the electric drive. In particular, the electric motor generates a main drive torque for the electric drive and / or the vehicle.

The electric drive also has a supply device for supplying the electric motor with electrical energy. In particular, the supply device comprises power electronics, wherein a supply voltage applied to the supply device for the electric motor is converted in the power electronics. The supply device, in particular the power electronics, preferably has switching elements, in particular power modules.

Furthermore, the electric drive has a cooling circuit for cooling the supply device and / or for cooling the electric motor with a coolant. The coolant is preferably water-based or alcohol-based. It can optionally be provided that the cooling circuit has a coolant pump and / or that the cooling circuit is designed as an active cooling circuit. The coolant pump is preferably designed in terms of flow technology to deliver the coolant to the supply device and / or to the electric motor.

It can be provided that the cooling circuit supplies both the supply device and the electric motor in a first variant. In a second variant, the cooling circuit can supply the supply device without the electric motor, in a third variant the cooling circuit can supply the electric motor without the supply device.

It is provided that the supply device is arranged in a supply housing area. In particular, the electric drive has a preferably multi-part housing, the supply housing area forming a section of the housing. It is provided that the supply housing area has a wall section. In principle, the wall section can be designed to be separable from the supply housing area. It is preferred that the wall section is formed in one piece with the supply housing area.

The wall section has an inner cooling structure, the inner cooling structure having the coolant flowing through it and / or forming a fluidic section in the cooling circuit. The internal cooling structure preferably increases the surface area of the wall section in order to reduce the thermal resistance.

In the context of the invention, the electric drive has a heat conducting plate for covering the internal cooling structure and for coupling to the supply device. The internal cooling structure is fluidically closed off from the supply device by the heat-conducting plate, so that between the heat-conducting plate and the inner cooling structure and / or the wall section formed inner cooling volume can be flowed through by the coolant without loss. It can be provided that the guidance of the coolant between the heat conducting plate and the inner cooling structure and / or the wall section is designed in a meandering, labyrinth, coiled or zigzag shape. In particular, the guidance of the coolant between the inlet and the outlet of the inner cooling volume is designed in such a way that an artificially extended cooling path is formed. The supply device, in particular the power electronics, is arranged on the side of the heat conducting plate facing away from the cooling structure and / or the wall section, so that there is a thermal coupling between the supply device, in particular the power electronics, and the coolant via the heat conducting plate. The heat-conducting plate can be designed to be planar; in alternative configurations, the heat-conducting plate can also be implemented as a 3-D component. The inner cooling structure preferably extends flat and / or flat. According to the invention, the heat conducting plate is connected to the wall section via a material connection. In particular, the material connection forms a seal for sealing off the inner cooling volume. The stiffness of the supply housing area is positively influenced by the material connection. Furthermore, an additional seal can be saved. A screw connection can also be dispensed with, so that manufacturing costs can be further reduced.

In a preferred embodiment of the invention, the material connection can be implemented as a soldered connection. This type of material connection has the advantage over welding, for example, that the temperatures required are lower, so that distortion of the supply housing area or other components is reduced or eliminated.

The soldered connection can be implemented particularly easily by placing a soldering foil between the supply housing area and the heat conducting plate during assembly and then partially or completely heating the assembly in order to melt the solder and establish the integral connection.

It is particularly preferred that the material connection runs in a closed circumferential manner around the inner cooling structure. This means that no further seal is required.

The electric drive preferably has a transmission for guiding the drive torque. In this case, the transmission can optionally have at least or precisely one transmission section for transmission of the drive torque, in particular from a high speed to a low speed. Alternatively or in addition, the transmission can have a shift section for shifting different gear ratios. As an alternative or in addition, the transmission can have a differential section for distributing the drive torque, in particular the translated drive torque, to two outputs.

The electric drive optionally has an oil circuit, in particular a lubrication system, to supply the transmission with oil. The transmission is preferably arranged in a transmission space, the transmission being lubricated and cooled with the oil in the transmission space. The oil circuit is particularly preferably designed as an active oil circuit and / or comprises an oil pump for actively conveying the oil in the oil circuit. The oil pump is preferably designed in terms of flow technology to deliver the oil from an oil sump in the transmission chamber and to supply it to the transmission. The oil sump can in particular be a dry sump or a wet sump.

The electric drive has a heat exchanger section, the heat exchanger section being coupled on one side to the cooling circuit and on the other side to the oil circuit. The term “page” should preferably be understood as being functional. The heat exchanger section is designed in particular to transfer thermal energy from one material flow to another. In particular, thermal energy is transferred from the material flow of the oil to the material flow of the coolant. However, it can also be provided that - especially in the case of a cold start of the electrical drive - thermal energy is transferred from the material flow of the coolant to the material flow of the oil, since the supply device and / or the electric motor thermal energy earlier due to electrical power loss during a cold start than the transmission provides.

The cooling management of the electric drive is advantageously designed as a system-integrated solution that uses the cooling circuit already present in the electric drive. The heat exchanger section is intended to cool the transmission oil in driving situations with high power losses. At the same time, the oil should be brought to operating temperature as quickly as possible in cold start situations in order to reduce the power losses in the transmission. The heat exchanger section thus becomes a thermal management component.

If necessary it would be conceivable to have a second electric motor also for the main drive or as a torque vectoring drive. The oil for this electric motor can then also be cooled from the supply device.

It is provided that the wall section forms part of the heat exchanger section. In particular, the wall section separates the side with the cooling circuit from the other side with the oil circuit. In this structural embodiment, the heat exchanger section comprises the wall section shown, the side of the heat exchanger section for the oil circuit forming an outer wall area and the side of the heat exchanger section for the cooling circuit forming an inner wall area. It is possible to thermally couple the supply device via the inner wall area, preferably to thermally couple it directly, and to thermally couple the oil circuit, preferably to thermally couple it directly, via the outer wall area. In this embodiment, a structurally simple and at the same time space-saving embodiment is given. In a preferred implementation of the invention, the wall section has an outer cooling structure, the outer cooling structure having the oil flowing through it and / or forming a fluidic section in the oil circuit. The outer cooling structure preferably increases the surface area of the wall section in order to reduce the thermal resistance.

The electric drive has an end cover, the end cover closing the heat exchanger section. In particular, the end cover delimits an oil guide area in the heat exchanger section. The end cover is preferably arranged on an underside of the electric drive.

In addition, it is proposed that the cover has at least one functional area, the functional area being designed as a counter cooling structure, as an oil pan area and / or as a pump interface for receiving an oil pump. The end cover can thus have exactly one of the named functional areas, exactly two of the named functional areas or all three named functional areas.

The end cover is particularly preferably designed in one piece and / or in one piece. In particular, this consists, in particular comprising the functional area or areas, from a common material section. For example, the end cover is designed as a cast part, in particular as an aluminum die-cast part.

In the event that the functional area is designed as a counter cooling structure, it is preferred that the counter cooling structure forms part of the oil guide area in the heat exchanger section. In particular, the counter-cooling structure is arranged on an inside of the end cover, specifically molded on. It is preferred that the counter-cooling structure enlarges the surface of the cover on the inside compared to the base area of the cover in the area of the counter-cooling structure. Preferably, the surface of the cover in the area of the counter cooling structure is more than 1.3 times, preferably more than 1.5 times larger than the base area of the cover in the same area. The area of the counter cooling structure preferably corresponds to the area of the heat exchanger section.

In the event that the functional area is designed as an oil sump area, it is preferably provided that the oil sump area is trough-shaped or shell-shaped and / or can accommodate an oil volume of at least 0.3 l, in particular at least 0.4 l. The volume of oil to be taken up in the oil pan area is particularly preferably greater than the volume of oil to be taken up in the heat exchanger section.

In the event that the end cover has the counter cooling structure and the oil pan area, it is preferred that the oil pan area is arranged lower than the counter cooling structure in the installation position of the end cover.

In the event that the functional area is designed as a pump interface, it is preferred that the pump interface forms a fluidic and / or mechanical connection to an oil pump. In the event that the end cover comprises the counter-cooling structure, the oil pan area and the pump interface, it is preferred that the fluidic connection forms a fluidic connection to the oil pan area on the one hand and to the heat exchanger section and / or to the counter-cooling structure on the other.

The integration of at least one functional area in the cover makes it possible to transfer complex structures from the actual housing of the electric drive to the cover, so that the complexity of the actual housing can be reduced.

The outer cooling structure is closed off in terms of flow technology by the end cap, so that the oil can flow through the outer cooling volume formed between the end cap and the outer cooling structure and / or the wall section without loss. It can be provided that the oil is guided between the cover and the outer cooling structure and / or the wall section in a meandering, labyrinth, spiral or zigzag shape. In particular, the routing of the oil between the inlet and the outlet of the outer Cooling volume designed so that artificially an extended cooling path is formed.

The outer wall area facing the oil must be accessible for production for a corresponding tool part in the die-casting tool. It is therefore closed via the cover plate, which prevents fluid from escaping into the environment, for example by means of a screw connection and a flange seal. This cover is e.g. In plastic injection molding, but optionally also manufactured in a different manufacturing process. In the case of increased robustness requirements, a formed sheet metal part or a cast part, in particular a die-cast part, is particularly suitable.

The counter cooling structure and the outer cooling structure together form the oil guide area, the oil guide area having the oil flowing through it and / or forming a fluidic section in the oil circuit. The outer cooling structure and the counter cooling structure preferably interlock and / or are interlocked, so that the common oil guide area is lengthened. In particular, the interlocking takes place in the installed position of the end cover in the vertical direction.

In a preferred structural embodiment of the invention, the counter-cooling structure is designed as a plurality of ribs, the ribs being oriented transversely to the direction of flow in the oil circuit. The outer cooling structure particularly preferably engages in gaps between the ribs, in particular so that the oil guide area varies in height.

It is particularly preferred that the oil pan area is designed as a dry sump area. In this embodiment, the transmission is lubricated and / or cooled by an active oil supply, which is ensured by the oil pump.

In a preferred structural embodiment, the pump interface has a mechanical interface for a receiving housing for receiving the oil pump and / or for the oil pump directly. The pump interface also has a fluidic interface.

In a preferred development of the invention, in a first alternative, the electric drive has a motor housing area for the electric motor. The motor housing area forms a portion of the housing. The supply housing area and the motor housing area are formed integrally with one another. In a second alternative, the electric drive has a transmission housing area for the transmission. The gear housing area forms a portion of the housing. The supply housing area and the gear housing area are formed integrally with one another. Particularly preferably, the supply housing area and the additional area according to the alternatives are made in one piece from an aluminum alloy, preferably made by molding, especially by the die-casting process. In the case of both alternatives, the supply housing area can thus be produced inexpensively in addition to the respective other area. In this way, the greatest possible savings in components and a cost-effective design can be achieved. In a less preferred embodiment, the supply housing area can also be produced and / or arranged separately, with the fluidic connection being made via connecting elements, such as hoses or pipes.

• -Wärmeübergang von Öl zum Gehäusewerkstoff des Versorgungsgehäusebereichs;
• -Wärmeleitung im Gehäusewerkstoff;
• -Wärmeübergang von Gehäusewerkstoff zu Kühlmittel.

Thus, oil cooling preferably takes place in the following power flow:

• -Heat transfer from oil to the housing material of the supply housing area;
• -Heat conduction in the housing material;
• -Heat transfer from the housing material to the coolant.

The inner and / or the outer cooling structure can have cooling fins, cooling pins, cooling knobs or other shaped elements to enlarge the surface. In a particularly preferred embodiment, the inner cooling structure and / or the outer cooling structure is formed in one piece with the wall section and / or with the supply housing area, so that the cooling structure (s) can be manufactured together with the wall section and / or with the supply housing area, preferably in an original form. In this way, the heat exchanger section can be integrated particularly cost-effectively.

In a preferred embodiment of the invention, the electric drive is designed as an electric axle, the electric axle preferably having two output shafts, the output shafts each being operatively connected to a driven wheel of the vehicle. In this embodiment, the electric drive has a very compact structure, so that the heat management described can be used particularly effectively.

• 1 eine schematisierte dreidimensionale Darstellung eines elektrischen Antriebs für ein Fahrzeug als ein Ausführungsbeispiel der Erfindung;
• 2 eine Schnittdarstellung von dem Versorgungsgehäusebereich des elektrischen Antriebs in der 1 im Bereich eines Wärmetauscherabschnitt;
• 3 eine schematische dreidimensionale Draufsicht auf einen Innenwandbereich von dem Versorgungsgehäusebereich im Bereich des Wärmetauscherabschnitts;
• 4 eine schematische dreidimensionale Draufsicht auf einen Außenwandbereich von dem Versorgungsgehäusebereich im Bereich des Wärmetauscherabschnitts;
• 5 eine schematische, dreidimensionale Darstellung eines elektrischen Antriebs als ein weiteres Ausführungsbeispiel Erfindung;
• 6 eine dreidimensionale Explosionsdarstellung des Abschlussdeckels mit angrenzenden Komponenten des elektrischen Antriebs der 5;
• 7 eine Schnittdarstellung durch den elektrischen Antrieb der 5;
• 8 eine dreidimensionale Explosionsdarstellung des Abschlussdeckels mit angrenzendem Versorgungsgehäusebereich des elektrischen Antriebs der 5,
• 9 zeigt eine Schnittdarstellung durch einen elektrischen Antrieb als ein weiteres Ausführungsbeispiel der Erfindung;
• 10 eine schematische dreidimensionale Draufsicht auf einen Außenwandbereich von dem Versorgungsgehäusebereich im Bereich des Wärmetauscherabschnitts als ein weiteres Ausführungsbeispiel der Erfindung.

Further features, advantages and effects of the invention emerge from the following description of preferred exemplary embodiments of the invention as well as the attached figures. These show:

• 1 a schematic three-dimensional representation of an electric drive for a vehicle as an embodiment of the invention;
• 2 a sectional view of the supply housing area of the electric drive in FIG 1 in the area of a heat exchanger section;
• 3 a schematic three-dimensional plan view of an inner wall area of the supply housing area in the area of the heat exchanger section;
• 4th a schematic three-dimensional plan view of an outer wall area of the supply housing area in the area of the heat exchanger section;
• 5 a schematic, three-dimensional representation of an electric drive as a further embodiment of the invention;
• 6th a three-dimensional exploded view of the cover with adjacent components of the electric drive of the 5 ;
• 7th a sectional view through the electric drive of 5 ;
• 8th a three-dimensional exploded view of the cover with the adjacent supply housing area of the electric drive of 5 ,
• 9 shows a sectional view through an electric drive as a further embodiment of the invention;
• 10 a schematic three-dimensional plan view of an outer wall area of the supply housing area in the area of the heat exchanger section as a further embodiment of the invention.

The 1 shows an electric drive in a schematic, three-dimensional representation 1 for a vehicle, the electric drive being designed as an electric axle. The electric drive 1 has a housing 2 on, with the housing 2 functionally in a motor housing area 3 , a gear housing area 4th and into a utility housing area 5 can be divided. The case 2 is designed as a die-cast aluminum housing and implemented in several parts. In this embodiment form the gear housing area 4th and the utility housing area 5 a common component which is designed as a die-cast part made of an aluminum alloy.

In the motor housing area 3 is an electric motor 6th arranged, which a drive torque for the electric drive 1 provides. In the gearbox area 4th is a gear 7th arranged, the transmission 7th converts the drive torque and distributed it to two output shafts, not shown. In the utility box area 5 is a utility 8th arranged, which the electrical energy for the electric motor 6th provides. In particular, the supply device comprises 8th power electronics with switching elements and / or power modules for providing the electrical energy for the electric motor 6th .

The gear 7th is via an oil circuit 9 cooled with oil and lubricated, the cooling circuit 9 one or more oil pumps 10 has to promote the oil. The oil circuit 9 The components of the oil circuit are only shown in a highly schematic manner 9 can also be distributed differently.

The electric motor 6th and / or the utility 8th are via a cooling circuit 11 cooled with a coolant. Optionally, the cooling circuit 11 a coolant pump 12 on.

The utility housing area 5 has a heat exchanger section 13th on the functional thermal energy of the material flow of the oil from the oil cycle 9 to the material flow of the cooling jacket from the cooling circuit 11 or transmits in the opposite direction. The heat exchanger section 13th is in the first embodiment under an end cover 14th arranged or is formed by this, as will be explained below.

The 2 shows a schematic section through the heat exchanger section 13th , it can be seen that the heat exchanger section 13th through a wall section of the utility housing area 5 is formed. In particular, the heat exchanger section 13th integral with the supply housing area 5 educated.

On an outside wall area 15th has the heat exchanger section 13th external cooling structures 16 on which in the wall section in the outer wall area 15th are molded. Through the end cover 13th become the outer cooling structures 16 Fluidically closed, so that the outer cooling volume thus formed 23 directly and / or without loss with the oil in the oil circuit 9 can be flowed through.

On an interior wall area 17th has the heat exchanger section 13th internal cooling structures 18th which in the wall section in the inner wall area 17th are molded. By means of a heat conducting plate, which is only shown schematically 19th or another heat conducting body are the internal cooling structures 18th Fluidically closed, so that the inner Cooling volume 24 Loss-free with the coolant of the cooling circuit 11 can be flowed through. On the thermal plate 19th or the heat conducting body is the supply device 8th arranged so that waste heat generated during operation passes through the heat conducting plate 19th or the heat conducting body in the cooling circuit 11 can be discharged.

Between the internal cooling structures 18th and the external cooling structures 16 is a remaining wall section of the supply housing area 5 present, which has a fluidic separation, but a thermal coupling between the cooling structures 18th and 16 implements. In particular, the remaining wall section is made of the aluminum alloy of the supply housing area 5 educated.

The 3 shows a schematic three-dimensional plan view of the inner wall area 17th , it can be seen that the internal cooling structures 18th are arranged in a flat area and are formed by three subsections, which are flowed through in parallel according to the arrows and which are cooling pins to enlarge the surface 21a exhibit. There are also sealing elements 20th to recognize which the internal cooling volume is flowing through 24 fluidically with the heat conducting plate 19th or seal the heat conducting body.

The 4th shows a schematic three-dimensional plan view of the outer wall area 15th It can be seen that the external cooling structures 16 are also arranged in a flat area and are formed by two subsections which are flowed through in series and which have cooling pins 21b to enlarge the surface. There is also a circumferential flange seal 22nd to recognize which fluidically the outer cooling volume 23 with the end cover 14th seals.

The end cover 14th can - like this in the 2 indicated by a dotted line, a counter cooling structure 28 have, the counter cooling structure 28 into the outer cooling volume 23 protrudes and the surface of the end cover 14th enlarged compared to a flat design. This allows heat to pass through the end cover 14th are supplied or removed.

The 5 shows an electric drive in a schematic three-dimensional representation 1 as a second embodiment of the invention. The electric drive 1 has a housing 2 on, with the housing 2 a portion of a motor housing area 3 for coupling an electric motor, not shown, and a gear housing area 4th to accommodate a gear 7th having. It also has a housing 2 a utility housing area 5 for receiving a supply facility, not shown. In particular, the electric drive forms 1 the 5 and the following a variant of the electric drive 1 of the first embodiment. Reference is therefore made to the first exemplary embodiment for the description. In particular, the first and second exemplary embodiments differ in terms of the end cover 14th as well as the arrangement of the oil pump 10 .

The end cover 14th is designed as a metal part, in particular as a cast part, for example as an aluminum die-cast part. In the end cover 14th three functional areas are integrated, namely the counter cooling structure already mentioned 28 , an oil pan area 29 as well as a pump interface 30th .

The end cover 14th extends under the heat exchanger section 13th and / or the supply housing area 5 and an intermediate area between the motor housing area 3 and the transmission housing area 4th . The cover also protrudes 14th with the pump interface 30th laterally over the base of the housing 2 out so that the pump interface 30th next to the case 2 is arranged.

The 6th shows the end cover 14th in a single representation, with components for the oil pump 10 are graphically supplemented in an exploded view. On the end cover 14th is at the pump interface 30th a receiving housing 31 fastened by means of a screw connection, the oil pump 10 into the housing 31 is used. The pump interface 30th thus forms a mechanical interface for the oil pump 10 .

The oil pan area 29 is designed as a recess so that it provides an oil pan area volume of 0.5 l, for example. The oil pan area 29 is fluidic with the pump interface 30th connected so that the oil pump 10 Oil from the oil pan area 29 can pump out. In particular, the oil circuit runs 9 from the oil pan area 29 via the pump interface 30th and the oil pump 10 into the heat exchanger section 13th .

The counter cooling structure 28 is in the installation position of the end cover 14th higher than the oil pan area 29 arranged and has a plurality of ribs 32 on, with the ribs - like this best from the 8th can be seen across the oil circuit 9 in the heat exchanger section 13th are aligned. Because of the multitude of ribs 32 is the surface of the end cover 14th enlarged.

The 7th shows a schematic longitudinal section through the electric drive 1 the area of the heat exchanger section 13th . On the right side, in the transition area between the supply housing area 5 and the motor housing area 3 is the oil pan area 29 to recognize. Below the supply housing area 5 , especially in the area of the heat exchanger section 13th is the counter cooling structure 28 recognizable in the cut. In the wall section of the utility housing area 5 on the outer wall area 15th are external cooling structures 16 molded into spaces between the ribs 32 the counter cooling structure 28 intervene so that the outer cooling structures 16 with the counter cooling structure 28 is interlocked. Between the outer cooling structures 16 and the counter cooling structure 28 is at the oil guide area 33 in the outer cooling volume 23 formed, which is a portion of the oil circuit 9 forms. The oil guide area 33 runs alternately between lower-lying sections, which pass through the floor between the ribs 32 are formed, and higher lying sections, which through the ceiling between the outer cooling structures 16 are formed. In this way it is through the oil guide area 33 formed section of the oil circuit 9 formed extended so that a thermal connection is improved.

On the inner wall area 17th are internal cooling structures 18th arranged, in particular molded, which a portion of the inner cooling volume 24 and thus the cooling circuit 11 form. As in the previous embodiment, the internal cooling volume 24 for example by a heat conducting plate, not shown 19th covered, which is in thermal contact with the supply device, not shown 8th stands.

Optionally, it can be placed below the counter cooling structures 28 a reservoir (not shown) can be provided, which is fluidically connected to the oil pan area 29 connected is. In this way, a larger amount of oil can be in the oil circuit 9 to be provided. The reservoir can be placed in the end cap 14th to get integrated. The oil pan area 29 and optionally the reservoir form a low pressure area for the oil. In terms of flow, after the oil pump 10 closes in the heat exchanger section 13th a high pressure area for the oil in the oil circuit 9 at. Subsequently to the heat exchanger section 13th the oil circuit runs 9 into the gear housing section 4th to the transmission 7th .

In the 8th is the cover again 14th together with a partially cut end of the electric drive 1 or the supply housing area 5 shown. In this illustration is the oil circuit 9 as well as the cooling circuit 11 shown schematically, it can be seen that the two circuits 8th , 11 are oriented in opposite directions. This has the advantage that the greatest temperature differences always coincide. During a cold start, the cold oil hits the beginning of the heat exchanger section 13th on the coolant that is already in the heat exchanger section 13th has flowed through and thus through the supply facility 8th is already warmed up. This achieves maximum heating power for the oil. In the operating state, the oil can transfer heat to the cooling circuit 11 submit.

The 9 shows a second embodiment of the electric drive 1 in the area of the heat exchanger section 13th , in particular the internal cooling structures 18th are designed differently than in the 7th . The internal cooling structures 18th are rather realized like this in the 8th or. 10 is shown. For the remaining areas in the 9 refer to the description in the 7th referenced.

It can be seen that on the internal cooling structures 18th the thermal plate 19th is put on. In particular, the heat conducting plate 19th on the underside a flat or smooth surface, which on the inner cooling structures 18th contact and rest, so that channels for the coolant are formed. While the seal between the end cover 14th and the wall section 26th about seals 34 As is done for example O-rings or sealing cords, the heat conducting plate is 19th via a material connection 35 with the wall section 26th connected and sealed. The material connection 35 is a soldered connection that is made by using a soldering foil during assembly 36 ( 10 ) between the wall section 26th and the thermal plate 19th is inserted and this is thermally treated after insertion, so that the material connection 35 arises.

• - Auf eine separate Dichtung kann verzichtet werden.
• - Auf eine Verschraubung kann verzichtet werden, dadurch wird in der Montage der Aufwand auf ein Minimum reduziert.
• - Kosten der Normteile, Dichtung und Montage können eliminiert werden.
• - Steifigkeit des Gehäuses wird positiv beeinflusst (nahezu einteiliges Verhältnis).

The 10 shows the inner wall area 17th with the internal cooling structures 18th , which is the internal cooling volume 24 form in a plan view from above, the course of the integral connection 35 and / or the course of the inserted soldering foil 36 is shown. The material connection 35 and / or the soldering foil 36 is closed all around the inner cooling volume 24 in a parting plane between the heat conducting plate 19th and the wall section 26th educated. In contrast to sealing and screwing or welding, in which higher distortions are to be expected, the seal has over the soldered connection and / or soldering foil 36 the following advantages:

• - There is no need for a separate seal.
• - There is no need for a screw connection, which reduces the installation effort to a minimum.
• - Costs of standard parts, sealing and assembly can be eliminated.
• - The rigidity of the housing is positively influenced (almost one-piece ratio).

List of reference symbols

1

electric drive

2

casing

3

Motor housing area

4th

Gear housing area

5

Utility housing area

6th

Electric motor

7th

transmission

8th

Utility

9

Oil circuit

10

Oil pump

11

Cooling circuit

12th

Coolant pump

13

Heat exchanger section

14th

End cover

15th

Exterior wall area

16

external cooling structures

17th

Interior wall area

18th

internal cooling structures

19th

Thermal plate

20th

Sealing elements

21a, b

Cooling pins

22nd

Flange seal

23

outer cooling volume

24

internal cooling volume

25th

empty

26th

Wall section

27

Housing wall

28

Counter cooling structure

29

Sump area

30th

Pump interface

31

Receiving housing

32

Ribs

33

Oil guide area

34

poetry

35

material connection

36

Solder foil

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102018130124 [0003]

Claims (11)

Electric drive (1) for a vehicle, with at least one electric motor (6) for generating a drive torque for the electric drive (1), with a supply device (8) for supplying the electric motor (6) with electrical energy, with a cooling circuit (11) ) for cooling the supply device (8) and / or for cooling the electric motor (6) with a coolant, with a supply housing area (5), wherein the supply device (8) is arranged in the supply housing area (5) and wherein the supply housing area (5) has a wall section (26), the wall section (26) having an inner cooling structure (18), the inner cooling structure (18) having the coolant flowing through it and / or forming a fluidic section in the cooling circuit (11), characterized by a Heat conducting plate (19) for covering the inner cooling structure (18) and for thermal coupling with the supply device (8), the heat conducting plate over a material connection (35) is connected to the wall section (26). Electric drive (1) according to Claim 1 , characterized in that the material connection (35) is designed as a soldered connection. Electric drive (1) according to Claim 2 , characterized in that the soldered connection is formed by an inserted soldering foil (36). Electric drive (1) according to one of the preceding claims, characterized in that the material connection (35) runs in a closed circumferential manner around the inner cooling structure (18). Electric drive (1) according to one of the preceding claims, characterized by a gear (7) for guiding the drive torque, and with an oil circuit (9) for supplying the gear (7) with oil and a heat exchanger section, the wall section being part of a heat exchanger section (13) forms, wherein the heat exchanger section (13) is coupled on one side to the cooling circuit (11) and on the other side to the oil circuit (9), Electric drive (1) according to Claim 5 , characterized by a cover, wherein the cover (14) closes the heat exchanger section (13), the cover (14) has at least one functional area, the functional area as a counter cooling structure (28), as an oil pan area (29) and / or as a Pump interface (30) is designed for coupling an oil pump (10). Electric drive (1) according to Claim 5 , characterized in that the wall section (26) has an outer cooling structure (16), the outer cooling structure and the counter-cooling structure (28) jointly forming an oil guide area, the oil guide area having the oil flowing through it and / or a fluidic section in the oil circuit (9) forms. Electric drive (1) according to one of the preceding claims, characterized by a motor housing area (3) for the electric motor (6), the supply housing area (5) being formed in one piece with the motor housing area (3) and / or by a gear housing area (4) for the transmission (7) wherein the supply housing area (5) is formed in one piece with the transmission housing area (4). Electric drive (1) according to one of the preceding claims, characterized in that the inner and / or the outer cooling structure (16, 18) has cooling ribs, cooling pins, cooling knobs or other shaped elements. Electric drive (1) according to one of the preceding claims, characterized in that it is designed as an electric axle. Vehicle, characterized by an electric drive (1) according to one of the preceding claims.

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