Electric drive machine for a motor vehicle, and motor vehicle

Abstract

The invention relates to an electric drive machine (10) for a motor vehicle, comprising a housing (20), a rotor (18) and a stator (14), which are each arranged in the housing (12), wherein the housing (12) delimits a sump (22) arranged below the stator (14), in which a lubricant (24) can collect, and comprising a lubricant guide device (30), by means of which the lubricant (24) can be circulated within the housing (12) in dry sump operation, wherein the lubricant guide device (30) has a first suction nozzle (34) which is arranged in the sump (22) and by means of which lubricant (24) can be suctioned from the sump (22) to a main lubricant pump (44), wherein an intermediate storage volume (42) is provided downstream of the first suction nozzle (34) and upstream of the main lubricant pump (44), through which volume the lubricant (24) can flow downstream of the first suction nozzle (34) and upstream of the main lubricant pump (44) and in which the lubricant (24) can be temporarily stored.

Description

[0001] 24-2758

[0002] Electric drive motor for a motor vehicle and motor vehicle

[0003] The invention relates to an electric drive motor for a motor vehicle and to a motor vehicle with an electric drive motor.

[0004] From DE 102019130116 A1, an internal combustion engine with a lubricant sump is known, which can be arranged on the crankcase of the internal combustion engine. A crankshaft assembly, forming a connecting rod assembly, is arranged in the crankcase. In the installed position of the internal combustion engine, there is a lubricant level below the connecting rod assembly. A lubricant pump is provided, which draws lubricant from the lubricant sump through a suction snorkel and delivers it to the lubrication points of the internal combustion engine. The suction snorkel has an additional volume. This additional volume significantly increases the volume of the suction snorkel.

[0005] The object of the present invention is to provide a solution which enables a particularly compact design of an electric drive machine for a motor vehicle, whereby friction losses due to splashing of a rotor of the electric drive machine can be kept particularly low.

[0006] This problem is solved according to the invention by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and 24-2758

[0007] 2

[0008] Possible embodiments set out in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages and possible embodiments of the respective subject matter of the other independent claims as well as any possible combination of the subject matter of the independent claims, possibly in conjunction with one or more of the dependent claims.

[0009] The invention relates to an electric drive motor for a motor vehicle. The electric drive motor is configured to propel the motor vehicle using electrical energy. In addition to the electric drive motor, the motor vehicle may have a traction battery by means of which electrical energy can be supplied to the electric drive motor. In particular, the electric drive motor is configured to drive at least one wheel of the motor vehicle. The electric drive motor comprises a housing, a rotor, and a stator, each arranged within the housing. The rotor is configured to rotate about an axis of rotation relative to the stator during operation. In particular, it is provided that the rotor and the stator are completely enclosed by the housing. It is also specifically provided that the electric drive motor is designed as a radial flux machine.

[0010] The housing defines a sump located below the stator, in which a lubricant can collect. In particular, the lubricant can serve both to lubricate and to cool at least one component of the electric drive. For example, the lubricant can lubricate and cool the rotor and / or the stator of the electric drive. The electric drive further comprises a lubricant guide device by which the lubricant can be circulated within the housing in dry-sump operation. The lubricant is, in particular, oil. In dry-sump operation, the lubricant is pumped from the sump by means of a pump and stored in a lubricant reservoir separate from the sump.Furthermore, it is provided that a lubricant pump will deliver the lubricant from the lubricant reservoir to the lubrication points of the electric drive motor. In this dry sump operation, the pumping of the lubricant from the sump and its temporary storage in the lubricant reservoir 24-2758 results in

[0011] 3

[0012] This design ensures a particularly low surface level of lubricant in the sump, effectively preventing the rotor from immersing in lubricant collected in the sump and consequently avoiding rotor splashing. This minimizes friction losses in the electric drive motor caused by rotor splashing and lubricant ingress into the air gap between the rotor and stator. As a result, exceptionally high efficiency of the electric drive motor can be achieved.

[0013] The electric drive motor is designed with a lubricant supply system comprising a first intake port located in the sump. This port draws lubricant from the sump to a main lubricant pump. The main lubricant pump then delivers the lubricant to the lubrication points of the electric drive motor. Downstream of the first intake port and upstream of the main lubricant pump, an intermediate storage volume is arranged. This volume is filled with lubricant flowing through the intermediate storage volume after the first intake port and before the main lubricant pump. The lubricant is temporarily stored in this intermediate storage volume, thus serving as a lubricant reservoir for operating the electric drive motor in dry sump mode.In particular, it is designed that the intermediate storage volume is supplied with lubricant solely by suction via the main lubricant pump, located after the first intake port and before the main lubricant pump. The intermediate storage volume is thus situated within a lubricant channel running from the intake port to the main lubricant pump. The arrangement of the intermediate storage volume allows for a particularly compact design of the electric drive motor. Specifically, in its intended installation position within the vehicle, the electric drive motor has a very small vertical extent (z) because, due to the dry-sump operation, very little space is required for the sump below the rotor in the vehicle's vertical direction to reliably prevent the rotor from splashing in the lubricant.Furthermore, the lubricant guidance device exhibits particularly high robustness against longitudinal and / or lateral acceleration-intensive driving maneuvers of the motor vehicle having the electric drive motor, because of the24-2758.

[0014] 4

[0015] The arrangement of the intermediate storage volume between the intake nozzle and the main lubricant pump ensures that the intermediate storage volume is completely filled with lubricant during operation, thus reliably drawing in the lubricant by means of the main lubricant pump regardless of acceleration forces acting on the lubricant in the intermediate storage volume, and the risk of air being drawn in by the main lubricant pump is particularly low.

[0016] In a possible embodiment of the invention, the electric drive motor comprises an auxiliary lubricant pump, a second intake port, and an outlet port. The second intake port is located in the sump. Lubricant drawn in through the second intake port by the auxiliary lubricant pump can flow back into the sump via the outlet port after passing through the pump. The outlet port is positioned closer to the first intake port than the second intake port. In other words, the auxiliary lubricant pump is designed to transfer lubricant from a first region of the sump, where the second intake port is located, to a second region of the sump, in which both the outlet port and the first intake port are located.The auxiliary lubricant pump thus enables particularly high robustness of the electric drive motor against longitudinal and lateral accelerations acting on the lubricant in the sump during normal use of the electric drive motor in a motor vehicle. If the lubricant is mainly located in the second section of the sump, it can be drawn from the sump through the first suction port by the main lubricant pump.If, due to accelerations acting upon it, the lubricant is primarily located in the first region of the sump, then the auxiliary lubricant pump transfers the lubricant through the second intake port to the outlet port, thus moving it from the first region of the sump to the second region. From there, the lubricant can be extracted from this second region of the sump through the first intake port using the main lubricant pump. The auxiliary lubricant pump therefore serves to ensure that the main lubricant pump can reliably extract the lubricant from the sump, thereby maintaining a particularly low fluid level within the sump. 24-2758.

[0017] 5

[0018] In this context, it is specifically intended that the first and second intake ports are arranged axially offset from each other in the sump. The axial direction runs parallel to a longitudinal direction of the rotor's axis of rotation. In other words, the first and second sections of the sump are located one behind the other in the axial direction.If, therefore, a large part of the lubricant is located in the first area of ​​the sump due to accelerations acting on the lubricant in the axial direction, the auxiliary lubricant pump can ensure that the lubricant is conveyed from the first area of ​​the sump against the axial acceleration acting on the lubricant into the second area of ​​the sump, in which the lubricant can be drawn in through the first suction nozzle using the first main lubricant pump and conveyed to predetermined lubrication points of the electric drive machine.

[0019] In another possible embodiment of the invention, the electric drive unit comprises a double pump assembly with two distinct pump stages, the first of which provides the main lubricant pump and the second of which provides the auxiliary lubricant pump. Thus, instead of two separate pump assemblies, the electric drive unit comprises only the double pump assembly, resulting in a particularly simple design. For example, the double pump assembly may have a total power output of 400 watts. A single electric motor can therefore be used to pump the lubricant for both pump stages.For example, the first pump stage, which supplies the main lubricant pump, may be configured to deliver 15 liters of lubricant per minute, and the second pump stage, which supplies the second auxiliary lubricant pump, may be configured to deliver approximately 5.5 liters of lubricant per minute. Due to the dual-pump design, the electric drive unit thus comprises very few components and is therefore particularly simple in construction.

[0020] In another possible embodiment of the invention, it is provided that the first intake nozzle is arranged in a recessed area of ​​the sump.

[0021] In particular, in this deepened area of ​​the swamp, a [structure] is located in accordance with its intended purpose.24-2758

[0022] 6

[0023] The electric drive motor is installed in the vehicle at the lowest geodetic point of the sump. This ensures that any lubricant present in the sump reliably collects in the depression during operation, allowing the lubricant to be extracted particularly efficiently and with a very low risk of air being drawn in via the first intake nozzle in this recessed area.

[0024] In a further possible embodiment of the invention, the intermediate storage volume is arranged above the sump in its intended installation position. In particular, it can be arranged that the intermediate storage volume is located at least partially above the main lubricant pump. Because the intermediate storage volume is arranged above the sump in its intended installation position, the electric drive motor can be provided with a particularly small vertical extent in the vertical direction perpendicular to the axial direction along which the sump is located at the lowest point of the electric drive motor.

[0025] In another possible embodiment of the invention, the intermediate storage volume is arranged laterally to the stator of the electric drive motor in the vehicle when installed in its intended position. In other words, the intermediate storage volume is arranged laterally to the stator, at least partially, in a direction perpendicular to the vertical direction of the electric drive motor. The available installation space laterally to the stator can thus be used to temporarily store the lubricant in the intermediate storage volume.Furthermore, by designing the intermediate storage volume with a greater vertical extent than in the respective lateral directions perpendicular to the vertical direction, a particularly high robustness of the lubricant delivery device can be achieved with respect to longitudinal and lateral accelerations acting on the lubricant in the intermediate storage volume in the respective lateral directions, since the risk of air being drawn in from the intermediate storage volume by the main lubricant pump is particularly low because the intermediate storage volume is completely filled with lubricant. Even if the intermediate storage volume should not be completely filled with lubricant,24-2758.

[0026] 7

[0027] If, however, air should be present in the intermediate storage volume, it can be achieved by designing the intermediate storage volume with a greater extent in the vertical direction than in the respective lateral directions that lubricant is reliably drawn from the intermediate storage volume by means of the main lubricant pump, even under strong accelerations acting on the lubricant in the intermediate storage volume in the respective lateral directions.

[0028] In another possible embodiment of the invention, the electric machine additionally comprises a gearbox, which is lubricated by the lubricant. After lubrication of the gearbox, the lubricant can flow from this gearbox into the sump. In other words, in addition to the rotor and the stator, the gearbox is part of the electric drive machine. The lubricant is circulated through both the rotor and / or the stator and the gearbox. Thus, the lubricant can lubricate and cool a particularly large number of components of the electric drive machine, including the gearbox, the rotor, and / or the stator. This eliminates the need for multiple separate lubrication or coolant circuits.

[0029] As a result, the electric drive motor can be of a particularly simple design and have very few components.

[0030] In another possible embodiment of the invention, the intermediate storage volume is designed to hold between eight percent and 40 percent of the total lubricant 24 present in the electric machine. The intermediate storage volume is thus designed to temporarily store a large portion of the lubricant circulating within the electric drive machine, thereby keeping the surface level of the lubricant in the sump particularly low due to the dry sump operation.

[0031] As a result, the risk of losses in the electric drive motor due to rotor splashing can be kept particularly low.

[0032] The invention further relates to a motor vehicle, in particular a motor car, especially a passenger car, with an electric drive motor as already described in connection with the electric drive motor according to the invention. The electric drive motor can be part of an electric 24-2758

[0033] 8

[0034] The powertrain of the motor vehicle is designed to propel the motor vehicle using electrical energy.

[0035] Further features of the invention may become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0036] The drawing shows in:

[0037] Fig. 1 is a schematic perspective view of a section of an electric drive machine; and

[0038] Fig. 2 shows a schematic representation of the structure of the electric drive machine.

[0039] In the figures, identical and functionally equivalent elements are provided with the same reference symbols.

[0040] The drawing shows, in Fig. 1, a partial schematic perspective view and in Fig. 2 a schematic representation, an electric drive motor 10 for a motor vehicle. The electric drive motor 10 comprises a housing 12, which is partially shown in Fig. 1. Furthermore, the electric drive motor 10 comprises a stator 14 and a rotor 18, which is rotatable about an axis of rotation 16 relative to the stator 14 during operation, as indicated in Fig. 2. It is provided that at least the rotor 18 and the stator 14 are housed in the housing 12. In this design, the electric drive motor 10 additionally includes a gearbox 20. The housing 12 defines a sump 22 in which lubricant 24, in particular oil, dripping from the gearbox 20 and the rotor 18 and / or the stator 14 can be collected. In this design, the sump 22 comprises a first section 26 and a second section 28.The first section 26 and the second section 28 are arranged one behind the other in an axial direction A of the electric drive motor 10, which runs parallel to the longitudinal direction of the axis of rotation 16. In Fig. 24-2758.

[0041] 9

[0042] Figure 2 shows, for a better understanding of the lubricant flow of the lubricant 24 within the electric drive machine 10, the second section 28 of the sump 22 spaced apart from the stator 14 and the rotor 18, and enlarged. The actual arrangement of the first section 26 to the second section 28 can be seen particularly well in Figure 1.

[0043] It is provided that the lubricant 24 is circulated within the electric drive 10. For this purpose, the electric drive 10 includes a lubricant supply device 30, by means of which the lubricant 24 can be circulated within the electric drive 10 in dry sump operation. The lubricant supply device 30 comprises a double pump device 32, a first intake port 34, a second intake port 36, an outlet port 38, and several lubricant lines 40 connecting the respective components of the lubricant supply device 30. Furthermore, the lubricant supply device 30 includes an intermediate storage volume 42. The intermediate storage volume 42 is designed to hold between eight percent and 40 percent of the total lubricant 24 volume present in the electric drive 10.The present design provides that the double-pump device 32 has two different pump stages, the first of which provides a main lubricant pump 44 and the second an auxiliary lubricant pump 46. In particular, it is provided that the volume flow rate of the auxiliary lubricant pump 46 is approximately 20 percent to 70 percent of the volume flow rate of the main lubricant pump 44. In Figures 1 and 2, the numbers 1 to 5 indicate which of the lubricant lines 40 shown in Figure 1 are supplied with lubricant 24, and when and how.

[0044] As can be seen particularly well in the illustration in Fig. 1, the outlet nozzle 38 is arranged closer to the first intake nozzle 34 than the second intake nozzle 36, and the first intake nozzle 34 and the second intake nozzle 36 are arranged offset from each other in the axial direction A. It is provided that lubricant 24, located in the first area 28 of the sump 22, is drawn in by means of the first intake nozzle 34, flows via a lubricant line 40 to the intermediate storage volume 42, and then flows to the main lubricant pump 44. In other words, the 24-2758

[0045] 10

[0046] An intermediate storage volume 42 is arranged downstream of the first intake port 34 and upstream of the main lubricant pump 44. The lubricant 24 flows through the first intake port 34, the lubricant line 40 connected to the first intake port 34, and the intermediate storage volume 42 solely as a result of the suction by the main lubricant pump 44. In other words, the lubricant is conveyed from the first intake port 34 to the main lubricant pump 44 solely by the suction force of the main lubricant pump 44. The intermediate storage volume 42 is thus traversed by the lubricant 24 after it has passed through the first intake port 34 and before it passes through the main lubricant pump 44. The lubricant 24 can be temporarily stored in the intermediate storage volume 42 and thus serve as a lubricant reservoir, enabling the electric drive motor 10 to be operated in dry sump mode.

[0047] The second intake port 36 is located in the first section 26 of the sump 22. Lubricant 24 can be drawn from the first section 26 of the sump 22 to the auxiliary lubricant pump 46 via the second intake port 36 and delivered by the auxiliary lubricant pump 46 to the discharge port 38. In this design, the discharge port 38 is located in the second section 28 of the sump 22. Thus, lubricant 24 can be delivered from the first section 26 of the sump 22 to the second section 28 of the sump 22 by means of the auxiliary lubricant pump 46. In particular, the housing 12 has a recess in a wall bounding the second section 28 of the sump 22, in which the first intake port 34 is located.This ensures that lubricant 24 is reliably drawn into the second area 28 of the sump 22, particularly in the recess in the second area 28 of the sump 22, via the first intake port 34, and that the intake of air via the first intake port 34 can be particularly well avoided.

[0048] As can be seen in Fig. 1, the intermediate storage volume 42 is arranged above the sump 22 in its intended installation position. In this case, the intermediate storage volume 42 is arranged laterally to the side of the stator 14. The described electric drive motor 10 exhibits particularly high robustness with regard to lubricant flow during driving maneuvers involving intensive longitudinal and / or lateral acceleration. 24-2758

[0049] 11

[0050] By using oil, especially gear oil, as the lubricant 24, only a particularly small quantity of lubricant 24 is required. The intermediate storage volume 42 allows for a particularly large intake volume for the main lubricant pump 44 in the intake lubricant guide from the first intake port 34 to the main lubricant pump 44, thus ensuring a particularly low surface level of lubricant in the sump 22. Furthermore, the auxiliary lubricant pump 46 supplies lubricant 24 to the first intake port 34, thereby minimizing the risk of the first intake port 34 running dry.

[0051] Overall, the invention thus shows how a circulating sump device of the electric drive motor 10 for cooling and lubrication exclusively with the lubricant 24 can be used to ensure the robustness of the lubrication system of the electric drive motor 10 during longitudinal and / or lateral acceleration-intensive driving maneuvers by providing an additional suction line volume, in this case the intermediate storage volume 42.24-2758

[0052] 12

[0053] Reference symbol list

[0054] 10 electric drive motor

[0055] 12 cases

[0056] 14 Stator

[0057] 16 axis of rotation

[0058] 18 Rotor

[0059] 20 gearboxes

[0060] 22 Swamp

[0061] 24 lubricants

[0062] 26 first area

[0063] 28 second area

[0064] 30 Lubricant supply device

[0065] 32 Double pump device

[0066] 34 first intake manifold

[0067] 36 second intake manifold

[0068] 38 outlet nozzles

[0069] 40 Lubricant line

[0070] 42 intermediate storage volumes

[0071] 44 Main lubricant pump

[0072] 46 Auxiliary lubricant pump

[0073] A axial direction

Claims

24-2758 13 Patent claims 1. Electric drive machine (10) for a motor vehicle, comprising a housing (20), a rotor (18) and a stator (14), each arranged in the housing (12), wherein the housing (12) defines a sump (22) arranged below the stator (14), in which a lubricant (24) can collect, and comprising a lubricant guide device (30) by means of which the lubricant (24) can be circulated within the housing (12) in dry sump operation, wherein the lubricant guide device (30) comprises a first intake port (34) which is arranged in the sump (22) and by means of which lubricant (24) can be drawn from the sump (22) to a main lubricant pump (44), wherein an intermediate storage volume (42) is provided downstream of the first intake port (34) and upstream of the main lubricant pump (44).which can be supplied with lubricant (24) after the first intake port (34) and before the main lubricant pump (44) and in which the lubricant (24) can be temporarily stored.

2. Electric drive motor (10) according to claim 1, characterized by an auxiliary lubricant pump (46), a second suction port (36) which is arranged in the sump (22), and an outlet port (38) through which lubricant (24) drawn in by the auxiliary lubricant pump (46) via the second suction port (38) can flow back into the sump (22) after passing through the auxiliary lubricant pump (46), wherein the outlet port (38) is arranged closer to the first suction port (34) than the second suction port (36).

3. Electric drive motor (10) according to claim 2, characterized by the fact that The first intake manifold (34) and the second intake manifold (36) are arranged axially offset from each other in the sump (22).24-2758 14 4. Electric drive motor (10) according to claim 2 or 3, characterized by a double pump device (32) with two different pump stages, the first of which provides the main lubricant pump (44) and the second of which provides the auxiliary lubricant pump (46).

5. Electric drive machine (10) according to one of the preceding claims, characterized in that the first intake port (34) is located in a recessed area of ​​the sump (22).

6. Electric drive machine (10) according to one of the preceding claims, characterized in that the intermediate storage volume (42) is arranged in its intended installation position above the sump (22).

7. Electric drive machine (10) according to one of the preceding claims, characterized in that the intermediate storage volume (42) is arranged in the intended installation position to the side of the stator (14).

8. Electric drive machine (10) according to one of the preceding claims, characterized in that the electric drive machine (10) additionally includes a gearbox (20) which is lubricated by means of the lubricant (24), and from which the lubricant (24) flows into the sump (22) after lubricating the gearbox (20).

9. Electric drive machine (10) according to one of the preceding claims, characterized in that the intermediate storage volume (42) is designed to accommodate 8 percent to 40 percent of the total amount of lubricant (24) present in the electric drive motor (10).

10. Motor vehicle with an electric drive motor (10) according to one of the preceding claims.

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