Circulation sump device for an electric drive unit of a vehicle - Patents.com

Abstract

The present invention relates to a circulation sump device for an electric drive unit of a motor vehicle which can be lubricated and / or thermostated by a lubricant, comprising a lubricant sump having a first axial region and a second axial region, a lubricant reservoir extending downwardly and connected to the lubricant sump via a lubricant outlet, and a lubricant sump pump conduit configured to pump lubricant from the second axial region of the lubricant sump to the lubricant reservoir.

Description

[Technical field]

[0001] The present invention relates to a circulation sump device for an electric drive unit of a motor vehicle, as well as to an electric drive unit. [Background technology]

[0002] In many vehicle designs, the electric drive is located at the rear of the vehicle, under the luggage compartment (possibly in a common housing structure also for the transmission). Nevertheless, the largest possible luggage compartment volume and / or a third row of seats must be possible. At the same time, cars with electric drive require a closed underbody and diffuser for efficiency reasons.

[0003] Therefore, circulation sump systems, such as those known, for example, from DE 10 200 03 133 A1, are not suitable, or are only suitable to a limited extent, for motor vehicles, which have high requirements for the mass in the z direction.

[0004] Conversely, the electric drive unit must then be fitted into a very small linear dimension in the z direction. Due to this limited linear dimension in the z direction, the lubricant reservoir (which is also an oil reservoir, since oil is often used as lubricant and / or temperature regulator for the drive machine or the entire drive unit with transmission) cannot be located under the electric machine (which would also allow the oil to flow out) but must be located to the side. This can, under certain conditions, impair reliable oil suction during lateral acceleration, since when cornering in one direction the oil is trapped in the transmission and when cornering in the other direction the oil is trapped in the electric machine and does not flow out to the area for oil suction. If the oil is not suctioned in, the drive parts will suffer at least from lack of lubrication and / or overheating.

[0005] Particularly for drivers with a sporty driving tendency, high lateral dynamics are of considerable importance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] DE 102016215423 A1 Summary of the Invention [Problem to be solved by the invention]

[0007] Against this background, the object of the present invention is to provide an improved circulation sump arrangement for electric drive units of motor vehicles. [Means for solving the problem]

[0008] Each independent claim defines by its characteristic features a subject matter which solves this problem. The dependent claims relate to advantageous developments of the invention.

[0009] According to one embodiment, a recirculating sump device for an electric drive unit of a motor vehicle that can be lubricated and / or thermostated by a lubricant, in particular an oil, is disclosed. The recirculating sump device comprises at least: (a) A lubricant reservoir having a first axial region and a second axial region, which may be located in a transmission chamber of a drive unit or a component of the drive unit, such as a drive machine or a transmission. (b) A lubricant reservoir extending below the lubricant sump (relative to the direction of gravity and / or vehicle height) in a first axial region and connected to the lubricant sump via a lubricant outlet, i.e. a lubricant reservoir connected via a lubricant outlet that is particularly arranged between the first axial portion of the lubricant sump and the first axial portion of the lubricant reservoir. (c) a lubricant sump pump conduit configured to pump, in particular by a reservoir pump, lubricant from the second axial region of the lubricant sump to the lubricant reservoir, in particular to where the lubricant reservoir is located in the first axial region.

[0010] According to one embodiment, the drive shaft of the drive machine extends in the transverse vehicle direction, so that the first and second axial regions of the lubricant reservoir differ in particular in their transverse vehicle position.

[0011] The use of such a circulation sump system ensures a reliable supply of lubricant and / or coolant for the operation of the drive unit in any curve direction, even during dynamic cornering with high lateral acceleration, which is all the more important during dynamic driving maneuvers, which require high lubrication and / or cooling performance.

[0012] In addition, the concept leads to a significant reduction in the amount of oil required in electric drive units, especially when the z-dimension is limited, which means cost and weight benefits.

[0013] According to yet another aspect, an electric drive unit for a motor vehicle is disclosed, comprising an electric drive machine in a machine housing and a transmission in a transmission case, the machine housing and the transmission case can comprise a number of transmission chambers connected to each other, for example by lubricant spills, in which the respective components of the drive unit are accommodated. Thus, for example, lubricant accumulated in a transmission lubricant sump can, according to an embodiment of the invention, flow out into the lubricant sump of a circulation sump device upon sufficient accumulation and / or further appropriate vehicle tilt.

[0014] The electric drive unit is equipped with a recirculating sump arrangement according to an embodiment of the invention to ensure a reliable supply of lubricant to the drive unit.

[0015] According to one embodiment, the lubricant reservoir of the circulating sump device in the machine housing is formed on both sides of the stator core of the drive machine and / or the transmission lubricant reservoir in the transmission case can be emptied by overflowing into the lubricant reservoir of the circulating sump device in the machine housing.

[0016] This makes the invention applicable to recirculation sump systems for machine-transmission combinations.

[0017] According to one embodiment, the lubricant reservoir is arranged on the underside of the machine housing and extends laterally of the drive unit, in particular laterally of the vehicle, between the delivery outlet and the start of the lubricant sump pump conduit after installation in the motor vehicle.

[0018] The invention is based, inter alia, on the idea of ​​circulating the lubricant by means of a circulation sump device from a first lateral side of the electric machine to the other lateral side in a lubricant reservoir below the lubricant sump, from which suction can always be taken both when cornering to the left and when cornering to the right.

[0019] Here, according to one embodiment, the electric drive machine is incorporated with a rotor rotation axis extending laterally of the vehicle, such that a first axial portion of the lubricant reservoir includes an area on one side of the stator core and a second axial portion of the lubricant reservoir includes an area on the other side of the stator core.

[0020] In the machine housing, according to one embodiment, there is a lubricant sump arranged in two parts on both sides of the stator core. Below the first axial part of the lubricant sump there is a lubricant reservoir into which the lubricant can flow by gravity. From this lubricant reservoir, a feed pump arranged in a feed conduit leading from the feed outlet delivers the lubricant towards the required points for cooling and / or lubrication. In the second axial part of the lubricant sump there is no reservoir (or only a very small one). From there the lubricant is sucked out and circulated to the lubricant reservoir below the first axial part of the lubricant sump. A connecting conduit with a small cross section may be provided, allowing the lubricant sump to be bled when the lubricant pump is stopped and the lubricant level to be equalised.

[0021] According to one embodiment, the idea uses a two-stage lubricant pump that can fulfill the functions of reservoir pump and of feed pump for cost reasons, whereby according to one embodiment only one motor is used, on whose shaft two lubricant feeders are attached.

[0022] According to one embodiment, the baffle plate prevents air from being sucked into the pressurized area of ​​the lubricant circuit when cornering, in particular during dynamic changes of direction.

[0023] According to one embodiment, in the first axial region, stator coil ends on a first side of a stator core of a stator of a drive unit are located, and in the second axial region, stator coil ends on a second side are located, at these axial positions in the machine housing in each case in the curve direction, particularly large amounts of lubricant collect, from which it can be particularly well supplied to the feed section for further lubrication and / or cooling operations.

[0024] According to one embodiment, a reservoir pump is disposed within the lubricant sump pump conduit.

[0025] According to one embodiment, the lubricant sump pump conduit is arranged to extend from the axial end of the machine housing of the drive unit and / or the lubricant sump remote from the stator core in the second axial region, i.e. from which lubricant from the second axial region of the lubricant sump can be pumped out, so that even if lubricant accumulates in the second axial region, the feed pump can still supply lubricant from the first axial region to the feed section in sufficient quantity.

[0026] According to one embodiment, the lubricant outlet is arranged in the first axial region at an axial end of the machine housing of the drive unit and / or of the lubricant reservoir and / or of the lubricant sump remote from the stator core, so that even if the lubricant accumulates in the first axial region, the lubricant can still be sufficiently supplied from the first axial region to the feed section by the feed pump.

[0027] According to one embodiment, the feed outlet from the lubricant reservoir, in particular the feed outlet for the withdrawal of lubricant from the lubricant reservoir to a feed pump (which is configured to supply lubricant via a feed conduit to a component of the drive unit to be lubricated and / or cooled), is arranged at or near the axial position of the lubricant outlet, so that an optimal supply of lubricant to the feed pump at the beginning of the feed section can be achieved depending on other specifications such as geometry, lubricant flow rate, etc.

[0028] According to one embodiment, the lubricant reservoir also extends in the second axial portion, which allows the volume of the lubricant reservoir to be increased.

[0029] According to one embodiment, the lubricant reservoir is provided with a partition, in particular a baffle plate or other flow obstruction, the compressed oil inlet of the lubricant sump pump conduit and the delivery outlet from the lubricant reservoir being arranged on the same side of said partition, so that in many operating conditions a higher lubricant level can be achieved on the delivery section side than on the other side of the partition, since all inlets to the lubricant reservoir are arranged on the delivery side and the partition provides a flow obstruction towards the part of the lubricant reservoir on the other side of the partition.

[0030] According to one embodiment, the partition is configured to impede the flow of lubricant from the first axial region, in particular from the delivery outlet towards the second axial region.

[0031] According to one embodiment, between the lubricant reservoir and the second axial region of the lubricant reservoir, in particular on the side remote from the lubricant reservoir pump conduit, a connecting conduit is provided for equalizing the lubricant level and / or for bleeding the lubricant reservoir.

[0032] According to one embodiment, the feed pump, which is arranged in a feed conduit leading from the feed outlet, and the reservoir pump are formed with a common pump drive, in particular as a two-stage lubricant pump, which allows saving of installation space, drive power, weight and robustness.

[0033] Further advantages and application possibilities of the invention will become apparent from the following description of the drawings. [Brief description of the drawings]

[0034] [Figure 1] 2 shows a schematic diagram of an electric drive unit with a recirculating sump device according to an exemplary configuration of the invention when there is no lateral acceleration; [Diagram 2] FIG. 2 is a top view of the lubricant reservoir of the recirculating sump device of FIG. [Diagram 3]FIG. 2 shows the distribution of lubricant from the perspective of FIG. 1 when a large lateral acceleration is applied in the direction of the first curve. [Figure 4] FIG. 2 shows the distribution of lubricant from the perspective of FIG. 1 when a large lateral acceleration is applied in a second curve direction acting opposite to the first curve direction. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] 1 shows an electric drive unit 1 for a motor vehicle, which comprises an electric drive machine 2 in a machine housing 4 and a transmission 6 of the drive machine 2 in a transmission case 8. The electric drive unit is lubricated and thermostatable by means of a lubricant S and is provided with a circulation sump device 10 for this purpose.

[0036] The recirculating sump device 10 comprises a lubricant reservoir 12 which is formed in a first axial region A1 (reference number 12.1 for the part of the lubricant reservoir arranged therein) and in a second axial region A2 (reference number 12.2 for the part of the lubricant reservoir arranged therein).

[0037] The lubricant reservoirs 12 of the circulation sump system 10 are formed within the machine housing 4 on either side of the stator core of the drive machine 2 .

[0038] The transmission lubricant sump in the transmission case 8 can become empty by overflowing into the lubricant sump 12.1 of the circulation sump device 10 in the machine housing 4.

[0039] The lubricant reservoir 14 is arranged on the underside of the machine housing 4 and extends laterally of the drive unit 1 between a delivery outlet 24 and the beginning of the lubricant sump pump conduit 18 .

[0040] In the first axial region A1, the stator coil end 20.1 on a first side of the stator core is located, and in the second axial region A2, the stator coil end 20.2 on a second side of the drive unit 1 is located.

[0041] Furthermore, the circulation sump device 10 is provided with a lubricant reservoir 14 which extends below the lubricant reservoir 12 in the first axial region A1 and is connected to the lubricant reservoir via a lubricant outlet 16.

[0042] The circulation sump device 10 also comprises a sump pump conduit 18 extending from the second axial region A2 of the lubricant sump 12.2, which is configured to pump the lubricant S from the second axial region A2 of the lubricant sump 12.2 to the lubricant reservoir 14. For this purpose, a reservoir pump 22 is arranged in the sump pump conduit 18.

[0043] The lubricant reservoir pump conduit 18 is arranged in the second axial region A2 so as to extend from the axial end of the machine housing 4 remote from the stator core, i.e. in particular near a housing wall (in particular wall B) of the machine housing extending in the height direction.

[0044] The lubricant outlet 16 is arranged in the first axial region A1 at the axial end of the machine housing 4 facing away from the stator core, i.e. in particular near a housing wall of the machine housing extending in the height direction (in particular wall A, which at the same time also serves as a lubricant overflow point for the transmission case 8).

[0045] A delivery outlet 24 from the lubricant reservoir 14 is located axially at the lubricant outlet 16. The lubricant reservoir 14 also extends in the second axial portion A2.

[0046] A partition 26, which in this embodiment is formed as a baffle plate, is arranged in the lubricant reservoir 14. The compressed oil inlet 28 of the lubricant sump pump conduit 18 and the delivery outlet 24 from the lubricant reservoir 14 are arranged on the same side of the partition 26, here both on the left side of the partition in the figure.

[0047] 2, the partition 26 is realized in this example to be curved around the compressed oil inlet 28, so as to position the lubricant S even more favorably at the feed outlet 24. The partition 26 is thereby also configured to hinder the flow of the lubricant S from the first axial region A1, in particular the feed outlet 24, towards the second axial region A2.

[0048] In this way, during critical operating situations, the changed lubricant S is essentially provided in sufficient quantity at the feed outlet 24 so that the drive unit 1 can always be lubricated and cooled.

[0049] In an operating condition when there are no significant lateral accelerations, the existing amount of lubricant S and the action of gravity allow sufficient lubricant S to be available in the feed device 24 without any problems, so that the lubricant can be continuously fed through the outlet filter 25. This operating condition is shown in FIG.

[0050] Figure 3 shows the arrangement of the accumulated lubricant S during a sharp right curve (i.e. when there is a significant lateral acceleration in the first curve direction), and it can be seen that by locating the feed outlet 24 at the left side end of the machine housing 4 below the lubricant reservoir 12.1, sufficient lubricant is available at the feed outlet 24 in the first axial region A1 to be fed by the feed pump 32.

[0051] FIG. 4 shows the arrangement of the accumulated lubricant S during a sharp left turn (i.e., when there is significant lateral acceleration in the second curve direction), and it can be seen that the supply of lubricant S to the delivery outlet 24 by the reservoir pump 22 is improved to the extent that essentially sufficient lubricant S is available at the delivery outlet 24 at any lateral acceleration.

[0052] Between the lubricant reservoir 14 and the second axial region A2 of the lubricant sump 12.2 there is a connecting conduit 30 provided for equalizing the lubricant level and for deaerating the lubricant reservoir 14.

[0053] The feed pump 32 arranged in a feed conduit 34 extending from the feed outlet 24 and the reservoir pump 22 are formed here as a two-stage lubricant pump with a common pump drive.

[0054] In this way, the feed pump 32 ensures a supply of lubricant S to the components of the drive unit 1 to be lubricated and / or cooled, regardless of the lateral acceleration of the vehicle. [Explanation of symbols]

[0055] 1 Electric drive unit 2 Electrical drive machine 4 Machine Housing 6. Transmission 8 Transmission case 10 Circulation Sump System 12;12.1,12.2 Lubricant reservoir 14 Lubricant Reservoir 16 Lubricant outlet 18 Lubricant sump pump conduit 20.1, 20.2 Stator coil end 22 Reservoir pump 24 Feed outlet 25 Exit Filter 26 Bulkhead 28 Compressed oil inlet 30 Connecting conduit 32 Feed pump 34 Feed conduit S Lubricant A1 First axial region A2 Second axial region

Claims

1. A circulation sump device (10) for an electric drive unit (1) of a motor vehicle that can be lubricated and / or thermostated by a lubricant (S), comprising: a lubricant reservoir (12; 12.1, 12.2) having a first axial region (A1) and a second axial region (A2), a lubricant reservoir (14) extending below the lubricant reservoir (12) in the first axial region and connected to said lubricant reservoir via a lubricant outlet (16); a lubricant sump pump conduit (18) configured to pump lubricant from the second axial region of the lubricant sump to the lubricant reservoir; A circulating sump device equipped with

2. 2. The recirculating sump system of claim 1, 1. A circulation sump device, characterized in that the first axial region is occupied by stator coil ends (20.1) on a first side of a stator core of the drive unit, and the second axial region is occupied by stator coil ends (20.2) on a second side of the stator core of the drive unit.

3. 3. The recirculation sump system according to claim 1 or 2, A recirculating sump system characterized in that a reservoir pump (22) is disposed in the lubricant sump pump conduit.

4. 3. The recirculation sump system according to claim 1 or 2, the lubricant sump pump conduit is arranged in the second axial region to extend from an axial end of the machine housing (4) and / or the lubricant sump remote from the stator core.

5. 3. The recirculation sump system according to claim 1 or 2, The lubricant outlet is arranged in the first axial region at an axial end of the machine housing and / or the lubricant reservoir and / or the lubricant sump that is remote from the stator core.

6. 3. The recirculation sump system according to claim 1 or 2, A recirculation sump arrangement characterized in that the lubricant reservoir delivery outlet (24) is located axially at or near the lubricant outlet.

7. 3. The recirculation sump system according to claim 1 or 2, The lubricant reservoir also extends into the second axial region.

8. 3. The recirculation sump system according to claim 1 or 2, 1. A recirculating sump system, characterized in that a partition (26), in particular a baffle plate or other flow obstruction, is arranged in the lubricant reservoir, and the compressed oil inlet (28) of the lubricant sump pump conduit and the delivery outlet from the lubricant reservoir are arranged on the same side of the partition.

9. 9. The recirculating sump system of claim 8, Circulation sump device, characterized in that the partition is configured to prevent the flow of lubricant from the first axial region, particularly the delivery outlet, towards the second axial region.

10. 3. The recirculation sump system according to claim 1 or 2, a connecting conduit (30) between the lubricant reservoir and the second axial region of the lubricant sump for equalizing the lubricant level and / or for bleeding the lubricant reservoir.

11. 3. The recirculation sump system according to claim 1 or 2, The circulation sump device is characterized in that the supply pump (32) arranged in the supply conduit (34) extending from the supply outlet and the reservoir pump are formed with a common pump drive, in particular as a two-stage lubricant pump.

12. An electric drive unit (1) for a motor vehicle, comprising an electric drive machine (2) in a machine housing (4) and a transmission (6) in a transmission case (8), A drive unit, characterized in that it comprises a circulation sump device (10) according to claim 1 or 2.

13. 13. An electric drive unit according to claim 12, 1. An electric drive unit, characterized in that the lubricant reservoir of the circulation sump device in the machine housing is formed on both sides of a stator core of the drive machine, and / or a transmission lubricant reservoir in the transmission case can be emptied by overflowing into the lubricant reservoir of the circulation sump device in the machine housing.

14. 13. An electric drive unit according to claim 12, 1. An electric drive unit, comprising: a lubricant reservoir disposed below the machine housing and extending laterally of the drive unit between the delivery outlet and the beginning of the lubricant sump pump conduit.

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