CN117813753A - Cooling system for cooling a hybrid vehicle or an electrically driven vehicle - Google Patents

Abstract

The invention relates to a cooling system (1) for cooling a vehicle, comprising a first electric machine (2), wherein the first electric machine (2) comprises a first rotor (3) which is rotatably mounted about a rotational axis (R) and an output shaft (14), and wherein the first rotor (3) extends in an axial direction (A) about the rotational axis (R), the first electric machine further comprises a first stator (3) which peripherally surrounds the first rotor (3), wherein the cooling system (1) further comprises a second electric machine (2 a) which is mounted axially adjacent to the first electric machine (2), wherein the second electric machine (2 a) comprises a second rotor (3 a) which is rotatably mounted about the rotational axis (R) and an output shaft (14), and wherein the second electric machine further comprises a second stator (4 a) which peripherally surrounds the second rotor (3 a), wherein the cooling system (1) comprises a common housing (6) which forms a housing for the first electric machine (2) and the second electric machine (2 a), wherein the first electric machine (2 a) comprises a first cooling circuit (2) and the first cooling circuit (2 a) which is provided in the axial direction, wherein the first coolant circuit comprises at least: a first coolant line (12) for cooling the first rotor (3) and the second rotor (3 a); and a second coolant line (13) parallel to the first coolant line (12) for individually cooling the first stator (4) and the second stator (4 a) through the second coolant line (13). The invention also relates to a vehicle cooling installation.

Description

Cooling system for cooling a hybrid vehicle or an electrically driven vehicle

Technical Field

The invention relates to a cooling system for cooling a hybrid vehicle or an electrically driven vehicle, comprising a first electric machine, wherein the first electric machine has a first rotor which is rotatably mounted about a rotational axis, wherein the first rotor is arranged coaxially to an output shaft, and wherein the rotational axis forms an axial direction, and wherein the first rotor extends about the rotational axis in the axial direction, and a first stator which peripherally surrounds the first rotor,

wherein the cooling system further has a second motor which is supported axially adjacent to the first motor,

wherein the second electric machine has a second rotor rotatably supported about the rotational axis, wherein the second rotor is supported coaxially with the output shaft, and wherein the second rotor extends in the axial direction about the rotational axis, and a second stator peripherally surrounding the second rotor,

wherein the cooling device has a common housing, which forms the housing of the first and second electric motor; wherein the output shaft extends through the housing in an axial direction, and wherein the first and second electric machines have a first coolant circuit with a first coolant for cooling the first and second electric machines.

The invention also relates to a vehicle cooling installation.

Background

The motor generates waste heat during operation due to electrical and mechanical losses. This requires cooling the motor in order to ensure a desired and efficient operation of the motor. Overheating of the motor may result in damage to the motor, such as damage to the motor bearings or stator insulation. The motor is typically arranged in a housing that completely encloses the motor and protects the motor from contamination, for example, due to dirt, oil or vapor. The cooling means are usually arranged in the housing or may be configured as a water jacket, for example.

The cooling system of an electric motor vehicle, which can be designed as a hybrid vehicle or a pure electric vehicle, differs greatly from the cooling system of a motor vehicle which is driven exclusively by means of an internal combustion engine.

DE 10 2019 110 432 A1 discloses: an oil cooling system arranged to circulate oil through the electric machine and the oil-coolant-heat exchanger; a coolant system having a piping arranged to pass a coolant loop through an inverter, a heat generating core, and a heat exchanger; and an air conditioning system arranged to circulate an air stream through the heat generating core for heating the vehicle cabin with waste heat of the motor and the inverter.

DE 10 2015 221 777 A1 discloses a housing arrangement for an electric machine, which housing arrangement comprises: a housing with a stator receiving area; a stator of an electric machine disposed within a stator receiving area of the housing; and a cooling jacket surrounding the stator for liquid cooling of the stator, wherein the outer wall of the stator simultaneously forms the inner face of the cooling jacket.

Disclosure of Invention

The object of the present invention is therefore to specify an improved cooling system for cooling a hybrid vehicle or an electrically driven vehicle. Another object is to specify an improved vehicle cooling system.

This object is achieved by a cooling system having the features of claim 1 and a vehicle cooling system having the features of claim 15.

Further advantageous measures are listed in the dependent claims, which measures can be combined with each other in a suitable manner in order to achieve further advantages.

This object is achieved by a cooling system for cooling a hybrid vehicle or an electrically driven vehicle, comprising a first electric machine, wherein the first electric machine has a first rotor which is rotatably mounted about a rotational axis, wherein the first rotor is arranged coaxially to an output shaft, which can be embodied at least in sections as a hollow shaft, and wherein the rotational axis forms an axial direction, and wherein the first rotor extends in the axial direction about the rotational axis, wherein the first electric machine further has a first stator which peripherally surrounds the first rotor, and wherein

Wherein the cooling device further has a second motor supported axially adjacent to the first motor, and

wherein the second motor has a second rotor rotatably supported about the rotation axis, wherein the second rotor is supported coaxially with the output shaft, and wherein the second rotor extends in the axial direction about the rotation axis, and a second stator peripherally surrounding the second rotor, and

wherein the cooling device has a common housing, which forms a housing for the first and the second electric motor; wherein the output shaft extends through the housing in an axial direction, and wherein the first and second electric machines have a first coolant circuit with a first coolant for cooling the first and second electric machines,

wherein the first coolant circuit comprises at least a first coolant line for cooling the first rotor and the second rotor and a second coolant line in parallel with the first coolant line for separately cooling the first stator and the second stator by the second coolant line.

The axis of rotation constitutes the axial direction. Here, the radial direction (radial direction) is orthogonal to the rotation axis.

By means of the invention, the first rotor and the second rotor and the two stators are cooled by two separate coolant lines. Thus, for example, the water jacket can be omitted and a more compact design can be achieved.

The rotor here comprises, for example, a rotor frame and an actual rotor, for example a lamination stack.

The first coolant may in particular be oil, which may also be used for lubrication.

By cooling the rotor and stator separately, improved cooling may be achieved.

By parallel cooling, hot spots inside the machine can also be prevented and a uniform cooling of the rotor as well as the stator can be achieved.

By cooling alone, it is possible to prevent: waste heat reaches the interior of the motor from the rotor or stator. It is also possible to prevent: the stator is then cooled too little due to, for example, excessive cooling of the rotor and warming of the coolant. Thereby, higher or more stable performance can be achieved.

In this case, it is also possible to provide a plurality of motors, in particular two motors.

In particular, the two motors are designed to be identical in size/shape and performance.

In a further embodiment, the first coolant circuit is configured such that the first coolant circuit merges into a common coolant circuit after cooling the first rotor and the second coolant circuit merges into a common coolant circuit after cooling the first stator and the second stator.

Furthermore, the first coolant circuit is configured such that the common coolant line is split into a first coolant line and a second coolant line after the coolant of the common coolant line is cooled in common.

With this arrangement, it is possible to achieve simple cooling of the coolant of the first coolant circuit. For example, the oil coolant can be fed back into a fluid reservoir, preferably an oil sump, and removed from the oil sump by an oil pump for common cooling as a common coolant line. Thereby, a simple cooling of the coolant in the first coolant circuit can be achieved. After cooling the coolant, a diversion of the common coolant line is performed.

In this case, coolant losses may be involved in the combination, in particular in the case of oil as coolant, since oil can also be used as lubrication. Thereby, the first/second coolant line has a coolant loss to some extent after cooling of the machine.

The required split-flow of the common coolant line for the first coolant line and for the second coolant line can be achieved here in accordance with the required coolant quantity of the rotor/stator. As such, depending on the implementation of an electric/hybrid vehicle having two or more electric machines, different amounts of coolant may be required for the rotor/stator. Such different partial flows can be achieved, for example, simply by different line sections through which the coolant flows.

In a further embodiment, the first common coolant line is connected to a heat exchanger for cooling the coolant, wherein the heat exchanger is connected to a separate second coolant circuit with a second coolant for cooling the first coolant flowing through the common coolant line by the second coolant.

The second coolant is thus used to cool the entire first coolant, in particular oil.

In a further embodiment, the output shaft has an output shaft outer side which points towards the two rotors, wherein a supply channel is provided in the housing, which supply channel is provided to extend preferably radially through the housing to the output shaft for supplying the first coolant into the housing interior and to the output shaft outer side, and wherein axially running passages are provided on the output shaft outer side, through which passages at least a part of the coolant of the first coolant line is guided along the output shaft outer side to the first rotor and the second rotor. A part of the coolant can be guided axially along the outside of the output shaft up to the differential provided in order to perform cooling and lubrication functions there as well.

In a further embodiment, the output shaft has an axial bore or is embodied at least in part as a hollow shaft, and the coolant of the first coolant line can be guided via the supply channel into the output shaft interior and axially through the output shaft. In this case, at least one radially extending through-opening is arranged in the output shaft in the circumferential direction, for example in the form of a bore, which extends from the output shaft interior to the output shaft outside for conveying at least a part of the first coolant line to the output shaft outside, so that an additional fluid flow of the first coolant line on the output shaft outside for cooling can be achieved after the conveying.

Preferably, in case there are a plurality of through openings in the output shaft extending radially in the circumferential direction, these through openings are arranged equally circumferentially.

In a further embodiment, a plurality of further through openings arranged in the circumferential direction are arranged in the output shaft or in a further component arranged in the housing between the first rotor and the second rotor, so that at least a part of the coolant of the first coolant line can be divided into a first lower coolant path after being conveyed along and/or through the output shaft outside for cooling the first rotor via the first lower coolant path and into a second lower coolant path for cooling the second rotor via the second lower coolant path. Thereby, uniform cooling of the first rotor and the second rotor can be achieved.

The supply channel through the housing may be embodied, for example, as a bore. The inflow into the housing along the outside of the drive shaft and/or through the output shaft can take place by means of a pump, while at least a part of the coolant of the first coolant line is conveyed outside the output shaft or to the rotor by means of centrifugal forces occurring during operation. If the first coolant is oil, other passages or through openings extending radially in the circumferential direction may be provided for directly supplying a portion of the oil flowing therethrough as lubricant at particularly stressed members such as bearings or teeth.

Here, the passage is a gap or a leak through which oil is structurally provided. A through opening is an opening introduced exclusively in the component, such as a hole or a channel within and/or through the component profile.

In particular, the coolant, in particular oil, of the first coolant line flows axially centrally between the first rotor and the second rotor through radially oriented passages or through openings and from there through the rotor carrier in order to remove the heat occurring in the two rotors. Thus, rotor cooling of both rotors can be achieved by the first coolant line. In this case, after flowing through the radially extending through openings or passages, the first coolant line can be divided directly into a first lower coolant path and a second lower coolant path which runs axially opposite, wherein the first lower coolant path is directed axially in the direction of the first rotor for cooling the first rotor and the second lower coolant path is directed axially in the direction of the second rotor for cooling the second rotor.

The coolant, in particular oil, can then flow along the end faces of the two rotors (also due to centrifugal forces) to the stator underside of the respective stator facing the respective rotor and thus cool the respective stator from the rotor side.

In a further embodiment, a gear change transmission is provided, comprising: a first transmission portion provided with a switching device with one or more switching elements; and a second transmission part having at least one wheel set, wherein the at least one wheel set may in particular be formed by a plurality of coupled planetary wheel sets, and wherein the wheel set is arranged at least partially within the second (or first) rotor and the one or more switching elements are arranged at least partially within the first (or second) rotor.

The rotor, which is arranged coaxially to the axis of rotation, has an approximately cylindrical interior cavity in which the two transmission parts, the planetary gear set and the shift element can preferably be arranged, and if necessary the differential is arranged at least partially, which results in a saving in installation space.

For example, the first motor or the second motor may also be switched on only when required. It is also preferred that these switching elements are configured as claws, i.e. that a traction interruption occurs during the switching process. By means of the support of the second motor, load switching can be achieved.

The planetary gear set further comprises at least a sun gear, one or more planet gears and a ring gear. The shift device may be configured as a two, three or multi-speed shift transmission.

In this case, one power electronics is connected to the motor, i.e. to a switching device of the motor, for control.

In a further embodiment, the through-openings or passages arranged in the circumferential direction (radially oriented) are arranged between the first rotor and the second rotor such that at least a portion of the coolant of the first coolant line is divided from the outside of the output shaft after flowing through the one or more radially oriented through-openings and/or passages into a first lower coolant path which flows directly alongside the first transmission part towards the first rotor for cooling the first rotor by means of the first lower coolant path, and at least a portion of the coolant of the first coolant line is further divided into a second lower coolant path flowing opposite the first lower coolant path, wherein the second lower coolant path flows towards the second rotor for cooling the second rotor by means of the second lower coolant path.

In a further embodiment with two transmission parts arranged at least partially within the rotors, the through-openings or passages arranged in the circumferential direction (radially oriented) are arranged between the first rotor and the second rotor such that at least a portion of the coolant of the first coolant line is divided outside the output shaft into a first lower coolant path for cooling or lubricating the first transmission part, in particular the switching device, wherein after cooling the first transmission part, the first lower coolant path flows to the first rotor for cooling the first rotor via the first lower coolant path, and at least a portion of the coolant of the first coolant line is further divided into a second lower coolant path for cooling the second rotor flowing opposite to the first lower coolant path, wherein the coolant passes by the second transmission part, in particular the wheel set, wherein the second lower coolant path flows to the second rotor for cooling the second rotor via the second lower coolant path, in order to avoid the heat of the electric machine from entering the transmission, in particular the rotor, bypassing the second transmission part.

Here, the coolant flow of the second lower coolant path to the second rotor and the coolant flow from the first lower coolant path to the first rotor are realized substantially due to centrifugal forces. The first transmission part may also be arranged at least partially within the second electric machine, and the second transmission part may be arranged at least partially within the first electric machine.

Furthermore, the coolant may be oil, wherein the output shaft has one or more radial through openings for conveying a portion of the oil, so that direct lubrication of the different bearings and/or devices arranged in the two electric machines is enabled.

Thus, an efficient cooling of the two rotors and the transmission by the first coolant line and a lubrication of the individual components of the associated wear element, for example, can be achieved.

In a further embodiment, the first stator has a first winding head in each case axially at the end face and the second stator has a second winding head in each case axially at the end face, so that the first lower coolant path flows to the first winding head after cooling the first rotor due to centrifugal forces occurring as a result of the rotation, so that cooling of the first winding head of the first stator is brought about, and the second lower coolant path flows to the second winding head after cooling the second rotor due to these centrifugal forces, so that cooling of the second winding head of the second stator is brought about.

Thereby, the first coolant line is fully used for cooling the individual components, such as the bearings, and the winding heads of the first and second rotor and stator. The coolant, here for example oil, is then returned to the oil sump or collected there and pumped out of the oil sump as a common coolant line.

In a further embodiment, the first stator has a first stator upper side which is directed toward the housing, and the second stator has a second stator upper side which is directed toward the housing, wherein the first stator upper side has a plurality of first stator channels which run parallel to the rotor axis and are distributed over the axial length of the first stator and over the stator circumference. The first stator channels may each have a first radial inlet opening at the upper side of the first stator. Furthermore, the second stator upper side preferably has a plurality of second stator channels running parallel to the rotor axis and distributed over the axial length of the second stator and over the stator circumference, wherein each of these second stator channels has a radially penetrating second inlet opening on the second stator upper side. Furthermore, at least one distribution channel may be provided for supplying the coolant of the first coolant circuit as a second coolant line, wherein the distribution channel is arranged in the housing and extends through the housing to the first inlet opening and the second inlet opening for distributing the coolant of the second coolant line as a first upper coolant path to the first inlet opening and for distributing the coolant of the second coolant line as a second upper coolant path to the second inlet opening.

The coolant of the second coolant line is thus fed to the housing surrounding the stator and from there through the distribution channels in the housing to the first and second stator. Through which a coolant, preferably oil, flows into the first and second stator channels and absorbs and carries waste heat of the stators and cools them.

Thereby, by means of the second coolant line, a first upper coolant path and a second upper coolant path are created, which second upper coolant path cools the outer sides of the first and second stator.

In a further embodiment, the first inlet opening is arranged on the upper side of the first stator and the second inlet opening is arranged on the upper side of the second stator, so that the coolant flows into the first stator channel and the second stator channel in an evenly distributed manner.

Thus, by cooling the two coolant lines of the rotor and the stator in parallel and independently of each other, an improved efficient cooling may be achieved.

Preferably, the first stator has a number of first slots and first webs, wherein the number of first stator channels is equal to the number of first webs, and the second stator has a number of second slots and second webs, wherein the number of second stator channels is equal to the number of second webs.

Thereby, a targeted and good cooling of the stator is achieved.

In a further embodiment, the first stator has a first winding head on the end face in each case in the axial direction, wherein the first stator channels each extend on the upper side of the first stator up to the first winding head and open toward the first winding head, so that after the first coolant flows through the first stator channels, the first coolant can flow out onto the first winding head, and wherein the second stator has a second winding head on the end face in each case in the axial direction, wherein the second stator channels each extend on the upper side of the second stator up to the second winding head and open toward the second winding head, so that after the first coolant flows through the second stator channels, the first coolant can flow out onto the second winding head.

Thereby, complete cooling of the stator can be achieved. After cooling the winding heads, the oil flows back into the oil sump, for example, and from there is carried over as a common coolant line for cooling to the second coolant circuit via a heat exchanger. Thereby, efficient cooling of the heated oil can be achieved.

In a further embodiment, the first stator channel and the second stator channel have a cross-sectional shape that increases the surface, so that a higher level of heat dissipation is possible. This may be, for example, a flower, star or other rotationally symmetrical shape. Thereby, heat dissipation of the corresponding stator can be increased.

Furthermore, a third coolant line may be provided, which is separated from the common coolant line or from the first coolant line or the second coolant line. The third coolant line can be fed to the second transmission part, i.e. the wheel set, via through openings in the housing and/or in a component fixed relative to the housing and possibly via further passages and through openings, in order to cool the second transmission part alone. The coolant of the third coolant line can then be collected in an oil sump and re-supplied to the common coolant line.

In this way, an efficient cooling of the transmission and of the two rotors can be achieved while maintaining as little installation space as possible.

The object is also achieved by a vehicle cooling system having a cooling system as described above, comprising a separate second coolant circuit having a second coolant, wherein at least two power electronics are arranged in the second coolant circuit, which can be cooled by the second coolant of the second coolant circuit, wherein the two power electronics are configured to drive a first motor and a second motor, wherein a heat exchanger is also arranged in the second coolant circuit, which heat exchanger is arranged in the second coolant circuit downstream of the at least two power electronics, such that a cooling of the at least two power electronics is achieved first.

Here, the first power electronics drive the first motor and the second power electronics drive the second motor.

By preferential cooling of these power electronics, sensitive electronic devices, such as inverters, are first cooled, i.e. they are cooled more strongly than if they were first to the heat exchanger. Thereby, highly sensitive power electronics can be protected from damage due to excessive temperatures. As the second coolant, a refrigerant such as a water-glycol mixture/synthetic coolant may be used, but air may also be used as the second coolant.

Therefore, the second coolant is used to cool the first coolant, in particular the oil, only after cooling the power electronics. By means of this facility, an efficient cooling can be achieved, which preferentially cools the highly sensitive power electronics first. In addition, in the second coolant circuit, a heater, a consumer and a radiator may be arranged in this order after the heat exchanger. A water pump may also be present in order to cause convection of the second circuit.

Drawings

Further features and advantages of the invention emerge from the following description with reference to the accompanying drawings.

Wherein:

fig. 1: a cooling installation according to the invention is schematically shown;

fig. 2: a vehicle installation with a heat exchanger according to the invention is schematically shown.

Detailed Description

Fig. 1 shows a cooling installation 1 according to the invention.

The cooling installation 1 according to the invention has a first electric motor 2. The first motor 2 has a first rotor 3 and a first stator 4. The first rotor 3 is supported coaxially with and rotatably about a rotor axis R, which constitutes the axial direction a. Furthermore, the stator 4 is supported coaxially with the first rotor 3.

The first stator 4 has a first winding head 5 on the end face (end face) in the axial direction. The first rotor 3 is preferably configured as a stack of laminations on a rotor frame 34.

A second motor 2a is also provided, which is arranged in parallel with the first motor 2. The second electric machine likewise has a second rotor 3a which is supported coaxially with and rotatably about the rotor axis R and has a stator 4a. The first rotor 3 and the second rotor 3a are in each case connected to the rotor carrier 34 in a rotationally fixed manner.

The second stator 4a has second winding heads 5a on the end sides (on both end faces) in the axial direction.

The first motor 2 and the second motor 2a are mounted together in the housing 6. The housing 6 can be composed of one or more parts and is embodied in particular as a housing ring with a housing cover that can be fastened on both sides.

Furthermore, the first stator 4 has a first stator lamination stack 7 (also referred to as stator back), which is arranged facing away from the first rotor 3, i.e. toward the housing 6.

The second stator 4a furthermore has a second stator lamination stack 7a (also referred to as stator back), which is arranged facing away from the second rotor 3a, i.e. toward the housing 6.

Here, the first stator lamination stack 7 and the second stator lamination stack 7a may be fastened to the housing 6.

The cooling system 1 further has an output shaft 14, wherein the output shaft 14 extends in the axial direction a through the housing 6 and is partially embodied as a hollow shaft by means of an axially centrally running cooling bore 35. Here, the output shaft 14 has an output shaft outer side 17 directed toward the first/second rotors 3, 3 a.

The cooling installation 1 further comprises a gear change transmission provided with a first transmission part 9 with a shifting device. The switching device here comprises one or more switching elements. The switching element can also be configured as a claw.

The cooling system 1 further has a second transmission part 10 having at least one wheel set, wherein the second transmission part 10 can be formed in particular by a plurality of coupled planetary wheel sets.

The rotor 2, 2a arranged coaxially to the rotation axis R has an approximately cylindrical inner cavity in which the first transmission part 9, i.e. the shifting device with the shifting element, and the second transmission part 10, i.e. the wheel set, can be arranged, and if necessary also the axle differential 36, which results in a saving of installation space.

The cooling installation 1 has a first coolant circuit with oil as the first coolant.

The first coolant circuit has a common coolant line 11 which is split into at least two coolant lines, namely a first coolant line 12 and a second coolant line 13.

The first coolant line 12 flows through a feed channel 15 which extends radially through the housing 6 to the output shaft 14 for feeding oil to the output shaft and into the output shaft 14. For this purpose, the output shaft 14 is embodied at least in part as a hollow shaft. This is achieved by a centrally running cooling hole 35.

The supply passage 15 is arranged on the end face of the housing 6 so that convenient supply can be achieved, and thereby, oil flows along the drive shaft outside 17 and flows through the output shaft 14, whereby efficient cooling of the first rotor 2 and the second rotor 2a from the output shaft 14 side can be achieved.

In the output shaft 14, a radially extending through-opening 16 arranged in the circumferential direction from the cooling hole 35 to the output shaft outside 17 is provided for conveying at least a part of the coolant of the first coolant line 12 to the output shaft outside 17.

Furthermore, a further axially extending channel 24 is provided for conveying a portion of the oil along the output shaft outer side 17 of the output shaft 14, so that the oil can be guided axially along the output shaft outer side 17 to the radially extending through-opening 16 and to the axle differential 36.

The through opening 16 is here arranged essentially between the first transmission part 9 and the second transmission part 10. In this case, the transport through the through-openings 16 is essentially achieved by the centrifugal forces which occur during operation.

The first coolant line 12 flows at least partly through the central through opening 16 and is divided into a first lower coolant path 18 directed towards the first rotor and a second lower coolant path 19 directed towards the opposite direction, i.e. the direction of the second rotor.

Furthermore, radially extending through openings 16 may be provided for conveying a part of the oil from the output shaft 14 to the outside of the output shaft, so that direct lubrication of different bearings and/or devices arranged in the first electric machine 2 and/or the second electric machine 2a is enabled. Such a bearing is, for example, a needle bearing 20.

After cooling the first transmission part 9, i.e. the shift element, the first lower coolant path 18 flows towards the first rotor 3, preferably due to the centrifugal forces occurring, for cooling the first rotor 3 via the first lower coolant path 18. Where the oil flows along the rotor end face and thus cools the first rotor 3. Here, a part of the coolant of the first lower coolant path 18 may bypass the first transmission part 9 to flow directly to the first rotor 2.

The second lower coolant path 19 flows to the second rotor 3a for cooling the second rotor 3a, preferably due to the centrifugal forces occurring. Where the oil flows along the rotor end face and thus cools the second rotor 3a.

After cooling the first rotor 3, the oil of the first lower coolant path 18 flows out onto the first winding heads 5 of the first stator 4 in order to cool these first winding heads.

After cooling the second rotor 3a, the oil of the second lower coolant path 19 flows out onto the second winding heads 5a of the second stator 4a in order to cool these.

Furthermore, oil is used for cooling the rotor 3, 3a and the winding heads 5, 5a. The oil flowing through the first coolant line 12 is also used for lubricating the first transmission part 9 and/or also existing bearings, such as needle bearings 20, for example. In this case, additional individual through openings 16 in the form of bores are arranged in the output shaft 14 in order to guide the oil from the output shaft 14 specifically to the bearings and/or components for lubrication. In this case, the flow is mainly caused by the centrifugal forces occurring during operation, so that the oil pump can be essentially omitted in this regard.

After cooling the winding heads 5, 5a, the remaining oil is collected in an oil sump 21.

The second coolant line 13 is used to cool the two stators 4, 4a.

Here, the first stator 4 has a first stator upper side 22 in the first stator lamination stack 7 on the side facing the housing 6, and the second stator 4a has a second stator upper side 22a in the second stator lamination stack 7a on the side facing the housing 6.

Furthermore, first stator channels are provided which run in the first stator 4 within the axial length of the first stator 4 and parallel to the rotor axis R, have a first inlet opening 23 and each have an outlet opening at the end face which is directed toward the first winding head 5.

Furthermore, second stator channels are provided which run in the second stator 4 within the axial length of the second stator 4a and parallel to the rotor axis R, which have second inlet openings 23a and in each case have outlets on the end face which are directed toward the second winding head 5 a.

The first stator channel and the second stator channel are in this case each distributed approximately equidistantly over the circumference of the respective stator 4, 4 a. In particular, the number of first stator channels is equal to the number of first webs and first slots that the first stator 4 has, and the number of second stator channels is equal to the number of second webs and second slots that the second stator 4a has. Thus, good and sufficient cooling can be achieved.

At least one distribution channel (not shown) is also provided, which channels the oil of the second coolant line 13 through the housing 6 to the first inlet opening 23 as a first upper coolant path 25 and to the second inlet opening 23a as a second upper coolant path 25 a. From there the oil flows into the first inlet opening 23 and into the second inlet opening 23a.

The oil then flows through the first stator channels to the outlet openings on one side in each case axially and from there onto the two first winding heads 5 in order to cool them. The oil then flows back into the oil sump 21.

The oil then flows through the second stator channels to the outlet openings on one side in each case axially and from there onto the two second winding heads 5a in order to cool them. The oil then flows back into the oil sump 21.

A third coolant line 26 is also provided, which is separated from the common coolant line 11 or from the first coolant line 12 or the second coolant line 13. The third coolant line may be directed to the second transmission part 10, i.e. to the wheel set, in order to cool the second transmission part alone. For this purpose, through openings or special coolant channels can be provided in or on the housing 6 or a component fixed relative thereto, via which the coolant is guided axially to the second transmission part 10. The third coolant line 26 can then likewise be collected again in the oil sump 21.

In this way, an efficient cooling of the transmission and of the two rotors can be achieved while maintaining as little installation space as possible.

The common coolant line 11 leading out of the oil sump 21 is cooled by means of the heat exchanger 27 and the second coolant circuit.

The oil collected in the oil sump 21 is led out as a common coolant line 11 by means of an oil pump 30 for cooling by means of a second coolant circuit through a heat exchanger 27.

Fig. 2 shows a vehicle installation 28 with a heat exchanger 27 and a second coolant circuit.

The second coolant circuit has, for example, a water-glycol mixture and/or another synthetic coolant as coolant.

The second coolant circuit also has two power electronics 29, 29a for actuating the two electric machines 2, 2a. For this purpose, the two power electronics 29, 29a each have an inverter.

The second coolant circuit may also have, in order, a heater 33, a load 31 and at least one vehicle radiator 32, and a water pump 8 for circulating coolant in the second coolant circuit.

In this case, in the second coolant circuit, the heat exchanger 27 is arranged downstream of the at least two power electronics 29, 29a, so that the cooling of the at least two power electronics 29, 29a by the coolant is effected first.

The coolant thus flows after cooling the two power electronics 29, 29a to the heat exchanger 27, where it is connected to the coolant line 11. It is led from the oil sump 21 to the heat exchanger 27 by means of the oil pump 30 and is cooled by means of the heat exchanger 27. Then, after the cooling of the coolant line 11, the coolant line is split into at least one first coolant line 12 and at least one second coolant line 13 for cooling the first motor 2 and the second motor 2a.

Reference numerals

1. Cooling facility

2. First motor

2a second motor

3. First rotor

3a second rotor

4. First stator

4. Second stator

5. First winding head

5a second winding head

6. Shell body

7. First stator lamination set

7a second stator lamination stack

8. Water pump

9. A first transmission part

10. Second transmission part

11. Common coolant line

12. First coolant circuit

13. Second coolant circuit

14. Output shaft

15. Feed channel

16. Through opening

17. Outside of output shaft

18. First lower coolant path

19. Second lower coolant path

20. Needle roller bearing

21. Oil pool

22. The upper side of the first stator

22a second stator upper side

23. A first access opening

23a second inlet opening

24. Passage way

25. First upper coolant path

25a second upper coolant path

26. Third coolant circuit

27. Heat exchanger

28. Vehicle installation

29. First power electronic device

29a second power electronic device

30. Oil pump

31. Consumable device

32. Radiator for vehicle

33. Heater

34. Rotor frame

35. Cooling hole

36. Axle differential mechanism

R rotor axis

Aaxial direction

Claims (19)

1. A cooling installation (1) for cooling a hybrid vehicle or an electrically driven vehicle, the cooling installation (1) having a first electric machine (2), wherein the first electric machine (2) has a first rotor (3) which is rotatably supported about a rotational axis (R) and an output shaft (14), wherein the first rotor (3) is arranged coaxially to the output shaft (14), and wherein the rotational axis (R) forms an axial direction (A), and wherein the first rotor (3) extends in the axial direction (A) about the rotational axis (R), the first electric machine further having a first stator (3) which peripherally surrounds the first rotor (3),

wherein the cooling device (1) further comprises a second electric motor (2 a) which is supported axially adjacent to the first electric motor (2),

wherein the second electric machine (2 a) has a second rotor (3 a) which is rotatably mounted about the rotational axis (R), wherein the second rotor (3 a) is mounted coaxially to the output shaft (14), and wherein the second rotor (3 a) extends in the axial direction (A) about the rotational axis (R), and a second stator (4 a) which peripherally surrounds the second rotor (3 a),

Wherein the cooling installation (1) has a common housing (6) which forms a housing for the first electric machine (2) and the second electric machine (2 a), wherein the output shaft (14) extends through the housing (6) in the axial direction (A), and wherein the first electric machine (2) and the second electric machine (2 a) have a first coolant circuit with a first coolant for cooling the first electric machine (2) and the second electric machine (2 a),

it is characterized in that the method comprises the steps of,

the first coolant circuit comprises at least a first coolant line (12) for cooling the first rotor (3) and the second rotor (3 a) and a second coolant line (13) parallel to the first coolant line (12) for cooling the first stator (4) and the second stator (4 a) separately by means of the second coolant line (13).

2. The cooling installation (1) according to claim 1, characterized in that the first coolant circuit is configured such that the first coolant line (12) merges into a common coolant line after cooling the first rotor (3) and the second rotor (3 a) and the second coolant line (13) after cooling the first stator (4) and the second stator (4).

3. The cooling installation (1) according to claim 2, characterized in that the first coolant circuit is configured such that after the common coolant line (11) is cooled jointly, the common coolant line (11) is split into the first coolant line (12) and the second coolant line (13).

4. A cooling plant (1) according to claim 2 or 3, characterized in that the first common coolant line (11) is in connection with a heat exchanger (27) for cooling, wherein the heat exchanger (27) is in connection with a separate second coolant circuit with a second coolant for cooling the first coolant flowing through the common coolant line (11) by means of the second coolant.

5. The cooling installation (1) according to any one of the preceding claims, characterized in that the output shaft (14) has an output shaft outer side (17) directed towards both rotors (3, 3 a), wherein a feed channel (15) is provided in the housing (6), which feed channel is provided to extend radially through the housing (6) to the output shaft (14) for feeding coolant as a first coolant line (12) to the output shaft (14) and into the output shaft.

6. The cooling installation (1) according to any one of the preceding claims, characterized in that at least one through opening (16) arranged in the output shaft (14) in the circumferential direction extending radially to the output shaft outside (17) is provided for conveying at least a part of the first coolant line (12) to the output shaft outside (17) such that a fluid flow of the first coolant line (12) on the output shaft outside (17) is enabled after conveying for cooling.

7. The cooling installation (1) according to any one of the preceding claims, characterized in that between the first rotor (3) and the second rotor (3 a) a plurality of through openings (16) and/or passages (24) arranged in the circumferential direction are arranged, such that at least a part of the coolant of the first coolant line (12) after being fed to the output shaft outside (17) towards the output shaft (14) and after flowing through a plurality of through openings (16) and/or passages (24) arranged in the circumferential direction between the first rotor (3) and the second rotor (3 a) can be divided into a first lower coolant path (18) for cooling the first rotor (3) by means of the first lower coolant path (18) and into a second lower coolant path (19) flowing opposite to the first coolant path (18) for cooling the second rotor (3 a) by means of the second lower coolant path (19).

8. The cooling installation (1) according to any one of the preceding claims, wherein a gear change transmission is provided, comprising: a first transmission section (9) having one or more shift elements; and a second transmission part (10) having at least one wheel set, wherein the second transmission part (10) is arranged at least partially within the second rotor (3 a) and the first transmission part (9) is arranged at least partially within the first rotor (3).

9. The cooling arrangement (1) as claimed in claim 8, characterized in that a through opening (16) arranged in the circumferential direction is arranged flat between the first rotor (3) and the second rotor (3 a) such that at least a part of the coolant of the first coolant line (12) is divided from the output shaft outside (17) into a first lower coolant path (18) for cooling the first transmission part (9), wherein, after cooling the first transmission part (9), the first lower coolant path (18) flows to the first rotor (3) for cooling the first rotor (3) by means of the first lower coolant path (18), and at least a part of the coolant of the first coolant line is also divided into a second lower coolant path (19) for cooling the second rotor (3 a) flowing opposite to the first lower coolant path (18).

10. The cooling arrangement (1) according to any one of the preceding claims 7, 8 or 9, characterized in that the first stator (4) has a first winding head (5) at the end face in each case axially and the second stator (4 a) has a second winding head (5 a) at the end face in each case axially, such that the first lower coolant path (18) flows towards the first winding head (5) after cooling the first rotor (3) due to centrifugal forces occurring as a result of rotation, such that cooling of the first winding head (5) of the first stator (4) is brought about, and the second lower coolant path (19) flows towards the second winding head (5 a) after cooling the second rotor (3 a) due to centrifugal forces, such that cooling of the second winding head (5 a) of the second stator (4 a) is brought about.

11. The cooling installation (1) according to any one of claims 5 to 10, wherein the coolant is oil, wherein the output shaft (14) has one or more radial passages (24) for conveying a portion of the oil, enabling lubrication of different bearings and/or devices arranged in the first and/or second electric machine (2) and/or (2 a).

12. The cooling installation (1) according to any one of the preceding claims, wherein the first stator (4) has a first stator upper side (22) facing the housing (6), and wherein the second stator (5) has a second stator upper side (22 a) facing the housing (6), wherein the first stator upper side (22) has a plurality of first stator channels running parallel to the rotor axis (R) and distributed over the axial length of the first stator (4) and over the stator circumference, and wherein the first stator channels each have a first inlet opening (23) running radially through the first stator upper side (22), and the second stator upper side (22 a) has a plurality of second stator channels running parallel to the rotor axis (R) and distributed over the stator circumference, wherein the second stator channels each have a second inlet opening (23) running radially through the second upper side (22 a) and over the stator circumference, and wherein the first inlet opening (23) is arranged as a cooling circuit (13) and the cooling circuit (23) extends through the first inlet opening (23), to distribute the coolant of the second coolant line (13) as a first upper coolant path (25) to the first inlet opening (23) and to distribute the coolant of the second coolant line as a second upper coolant path (25 a) to a second inlet opening (23 a).

13. The cooling installation (1) according to claim 12, wherein the first stator (4) has a number of first slots and first webs, wherein the number of first stator channels is equal to the number of first webs, and the second stator (4 a) has a number of second slots and second webs, wherein the number of second stator channels is equal to the number of second webs.

14. The cooling arrangement (1) according to claim 12 or 13, characterized in that the first stator (4) has a first winding head (5) on the end face in each case axially, wherein the first stator channels extend on the first stator upper side (22) up to the first winding head (5) in each case and open towards the first winding head (5) so that after the first coolant has passed through the first stator channels, the first coolant can flow out onto the first winding head (5), and wherein the second stator (4 a) has a second winding head (5 a) on the end face in each case axially, wherein the second stator channels extend on the second stator upper side (22 a) up to the second winding head (5 a) in each case and open towards the second winding head (5 a) so that after the first coolant has passed through the second stator channels, the first coolant can flow out onto the second winding head (5 a).

15. The cooling installation (1) according to any one of claims 12 to 14, wherein the first stator channel and the second stator channel have a cross-sectional shape that increases the surface, enabling a higher level of heat dissipation.

16. The cooling installation (1) according to any one of the preceding claims, characterized in that a third coolant line (26) is provided, which is separated from the common coolant line (11) or from the first coolant line (12) or the second coolant line (13).

17. The cooling installation (1) according to claim 16, characterized in that coolant is fed to the second transmission part (10) via the third coolant line (26) through a through opening (16) in the housing and/or a component fixed relative to the housing and possibly further passages (24) and through openings (16) in order to cool the second transmission part alone.

18. The cooling installation (1) according to claim 16 or 17, characterized in that the coolant of the third coolant line (26) is re-supplied to the common coolant line (11) after the cooling process.

19. Vehicle cooling installation with a cooling installation (1) according to one of the preceding claims, having a separate second coolant circuit with a second coolant, wherein at least two power electronics (29, 29 a) are arranged in the second coolant circuit, wherein the two power electronics (29, 29 a) are configured to drive a first electric machine (2) and a second electric machine (2 a), wherein a heat exchanger (27) is also arranged in the second coolant circuit, which heat exchanger is arranged in the second coolant circuit after the at least two power electronics (29, 29 a) in such a way that a first cooling of the at least two power electronics (29, 29 a) is achieved.