Electric machine for powering a motor vehicle

Abstract

Electric machine (1) comprising - a machine housing (2) for receiving a rotor (4), a stator (3) and an output shaft (5), and - a venting element (10) with a collection chamber (11), with an inlet (12) and with at least one outlet (13, 14), wherein - the machine housing (2) forms an interior space (6) within which there is air which expands and creates an internal pressure (p) prevailing within the interior space (6). i ) increases when the electric machine (1) heats up during operation, - the inlet (12) of the venting element (10) is connected to the interior (6) of the machine housing (2), - at least one outlet (13, 14) of the venting element (10) is connected to an external environment (9) of the electrical machine (1), - the collection chamber (11) is arranged between the inlet (12) and the at least one outlet (13, 14) and is connected via the inlet (12) to the interior (6) of the machine housing (2) and via the at least one outlet (13, 14) to the external environment (9) of the electric machine (1), - the venting element (10) connects the interior (6) with the external environment (9) of the electric machine (1) in such a way that air escapes from the interior (6) via the inlet (12), the collection chamber (11) and the at least one outlet (12, 14) into the external environment (9) when the internal pressure (p i ) is higher than an external pressure prevailing in the external environment (9) (p a ).

Description

[0001] The invention relates to an electric machine for driving a motor vehicle.

[0002] An electric motor used to power a motor vehicle heats up and cools down. The volume of air enclosed within the motor's interior, which expands and contracts due to temperature differences, can cause undesirable pressure changes within the motor's interior. Therefore, it is necessary to equalize the pressure between the motor's interior and its external environment. Various solutions for achieving pressure equalization are known in the art. With hose vents, the additional effort of routing a hose element into a dry space is required. If the dry space is formed by the driver's cab, this solution does not operate odor-free within the occupied space.With an alternative membrane solution, oil droplets can eventually clog micropores in the membrane, meaning this solution requires maintenance. With a simple vent featuring a rain guard and filter, there is a risk of pressurized water entering the interior of the electric motor.

[0003] If the electric machine has an oil bath for lubricating and / or cooling its components, a problem can arise where an opening for pressure equalization is exposed to oil mist from the inside and water or water vapor from the outside. The water or water vapor must not enter the interior of the electric machine, while the oil mist or its oil content must not escape into the external environment of the electric machine or into the environment.

[0004] US Patent 2003 / 0098204 A1 discloses a venting device for the powertrain of an electric vehicle comprising an electric motor and a transmission connected to the electric motor. The venting device includes a venting chamber located above a connecting section linking an electric motor housing and a transmission housing. Furthermore, the venting device includes a first venting passage connecting the venting chamber to an inner surface of the electric motor housing, and a second venting passage connecting the venting chamber to a lubricating oil separator formed within the transmission housing.

[0005] From JP 2013-177952 A, a power transmission device is further disclosed, comprising an oil-cooled motor with a rotating shaft as the output shaft to which the motor's power is transmitted, a gearbox to which power is transmitted from the rotating shaft, and a housing with a rear support formed between a motor chamber for accommodating the motor and a gearbox chamber for accommodating the gearbox. A drain opening is formed in the lower part of the gearbox housing to vent the gearbox chamber to the atmosphere. A connecting opening is formed in the rear support to allow a connection between the motor chamber and the gearbox chamber. Furthermore, a vent is provided to filter air flowing through the connecting opening.

[0006] An object of the present invention can be seen as providing an electric machine with a venting device that enables particularly effective and simple venting of the electric machine and at least reduces the ingress of foreign bodies. This object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject of the dependent claims, the following description, and the figures.

[0007] According to the present invention, it is proposed to attach a particularly large-volume element with a chamber to an electric machine, which, particularly by virtue of its shape, makes it more difficult for pressurized water, water, and steam, etc., to penetrate. In this sense, the present invention provides an electric machine for powering a motor vehicle. The electric machine comprises a machine housing for receiving a rotor, a stator, and an output shaft of the electric machine, and a venting element with a collection chamber, an inlet, and at least one outlet.

[0008] The machine housing forms an interior containing air, which expands and increases the internal pressure when the electric machine heats up during operation. The inlet of the venting element is connected to the interior of the machine housing. The at least one outlet of the venting element is connected to the external environment of the electric machine. The collection chamber is located between the inlet and the at least one outlet and is connected to the interior of the machine housing via the inlet and to the external environment of the electric machine via the at least one outlet.The venting element connects the interior of the electric machine to its external environment in such a way that air escapes from the interior via the inlet, the collection chamber, and at least one outlet into the external environment when the internal pressure is higher than the prevailing external pressure. The venting element prevents foreign particles that have entered the collection chamber from the external environment of the electric machine from passing through the inlet of the venting element into the interior of the machine housing.

[0009] The term "connected" or "connected" refers in particular to the fact that the interconnected elements are conductively connected to each other in such a way that air can flow from one element to the other and vice versa. This allows, in particular, pressure equalization between the interconnected elements. Foreign bodies can be understood to be, for example, solid particles such as dust. Furthermore, the foreign bodies can also be at least partially liquid, e.g., in the form of rainwater, water vapor, or pressurized water. Ice or snow can also be understood as foreign bodies within the meaning of the present invention. The venting element enables maintenance-free, adaptive venting of the electric motor with an oil bath. Over its service life, it also enables maintenance-free operation compared to a solution with a membrane.Furthermore, the venting element is easier to install compared to a prior art solution using a hose vent.

[0010] The shape of the collection chamber can be designed to make it difficult for pressurized water, water, and steam, etc., to penetrate. In particular, the at least one outlet can be located in a lower area of ​​the collection chamber, allowing any foreign particles that may have entered the chamber from the external environment to leave again by gravity. Furthermore, the collection chamber can be closed off laterally and from the top, preventing any foreign bodies from entering from the sides or top. Entry is only possible through the at least one outlet in the lower area, thus preventing a large proportion of foreign bodies from the external environment from entering the venting device.In this sense, according to one embodiment, at least one outlet is arranged on a lower surface of the collection chamber, wherein an upper surface and a lateral surface of the collection chamber are closed.

[0011] Preferably, the inlet is located in an upper region of the electrical machine, while the at least one outlet is located on the lower surface of the collection chamber. Thus, the inlet is positioned vertically above the at least one outlet. This results in a height difference between the inlet and the at least one outlet. If, for example, water enters the collection chamber, it must overcome this height difference before reaching the inlet to the interior of the machine housing. This risk exists only if the collection chamber is filled up to the inlet. This risk is particularly low due to the large volume of the collection chamber. Water that has entered the collection chamber will tend to flow out of it via the at least one outlet rather than accumulating up to the level of the inlet to the interior of the machine housing.This embodiment thus contributes to ensuring that large quantities of splash water can be collected in the collection chamber and, due to the height difference between the at least one outlet of the collection chamber and the inlet on the electric machine, do not enter the interior of the electric machine.

[0012] The collection chamber can be a large-volume element (chamber) that makes it more difficult for pressurized water, water, and water vapor, etc., to penetrate the interior of the machine housing. Due to its large volume, the electric machine is particularly resistant to splashing water during operation, because large quantities of splashing water can be collected in the chamber before they enter the interior of the machine housing through the inlet. In one embodiment, the collection chamber is designed to have an interior volume of at least 10% of the oil volume in the interior to be vented.

[0013] However, any water or water vapor that may have entered the collection chamber cannot reach the oil chamber or the interior of the machine housing via the drains, outlets, and condensation surfaces, but is instead separated again. In this sense, according to one embodiment, the collection chamber has at least one condensation surface and at least one guide rib. Water from water vapor that has entered the collection chamber condenses on the condensation surface, and the condensed water is then guided via the guide rib to the at least one outlet and flows out of the collection chamber through this outlet.

[0014] By providing multiple outlets (at least two) at spatially separated positions on the unit, the electric machine becomes particularly resistant to cleaning with a water jet. In particular, any water that enters through one outlet can drain out through the other. According to one embodiment, a first outlet is arranged at a first position on the lower surface of the collection chamber, while a second outlet is arranged at a second position on the lower surface of the collection chamber. The first position is located at a distance from the second position. Specifically, the first position can be located at one end of the collection chamber in a horizontal direction of the electric machine, and the second position at the other end of the collection chamber.

[0015] According to a further embodiment, the venting element comprises a first shell-shaped component and a second shell-shaped component, wherein the first shell-shaped component and the second shell-shaped component are detachably attached to one another and together form the collection chamber. The first shell-shaped component can, in particular, form a lower part of the collection chamber, in which the at least one outlet is also arranged. The second shell-shaped component can, in particular, form an upper part of the collection chamber. The lower shell-shaped component can also be an integral part of the machine housing. The two shell-shaped components according to this embodiment allow, in particular, modularity with regard to the shape and / or size of the collection chamber.

[0016] In this context, one of the two shell-shaped components can be replaced to allow for different chamber sizes within the collection chamber. Specifically, the second shell-shaped component, which forms the upper part of the collection chamber and contains the inlet, can be replaced. According to one embodiment, one of the two shell-shaped components can be replaced by an alternative shell-shaped component with a different shape, thus altering the chamber's internal volume. This embodiment provides an adaptable venting element that can be fully integrated with the unit.

[0017] The attached vent can, through a special design, occupy unused spaces within the unit's casing. In one embodiment, an upper part of the machine housing has an outer surface that forms an inwardly directed bulge, with the venting element located within this bulge.

[0018] In the area of ​​the inlet leading to the interior of the machine housing, the venting element can include a condensation section with a wire mesh to cool any oil mist rising from the interior and return it to the unit via a funnel-shaped contour of the condensation section. Splashing oil and oil mist are thus returned to the unit by this separation element and do not escape into the environment. In one embodiment, the venting element comprises a wire mesh plug and a funnel-shaped oil condensation element with an upper opening and a lower opening, the lower opening being connected to the inlet of the venting element and the upper opening being connected to the collection chamber. The lower opening of the funnel-shaped oil condensation element has a smaller inner diameter than the upper opening.The wire mesh plug is inserted into the upper opening and is permeable to air. Oil mist penetrating from the interior of the machine housing into the funnel-shaped oil condensation element cools down on an inner wall of the funnel-shaped oil condensation element and on the wire mesh plug, causing the oil contained in the oil mist to condense, sink by gravity, and flow back into the interior via the inlet of the vent element.

[0019] An additional integrated labyrinth can act as a dust barrier, preventing dust from accumulating on the wire mesh plug. In this respect, according to one embodiment, the venting element has a labyrinth structure, with the upper opening of the funnel-shaped oil condensation element being connected to the collection chamber via this labyrinth structure. This prevents dust particles entering the collection chamber from the external environment from reaching the wire mesh plug via the labyrinth structure. Additionally, the labyrinth structure provides a further barrier against oil escaping from the interior to the external environment, thus ensuring a particularly reliable prevention of oil from the interior of the machine housing into the environment.

[0020] In the following, exemplary embodiments of the invention are explained in more detail with reference to the schematic drawing, wherein identical or similar elements are provided with the same reference numeral. Here, [the following is shown] Fig. 1 a closed electrical machine, Fig. 2 a roughly schematic longitudinal section view of an embodiment of an electrical machine according to the invention with a venting element, Fig. 3 a perspective view of a venting element for the electric machine according to Fig. 2, Fig. 4 a perspective view of the venting element according to Fig. 3 on an electric machine, Fig. 5 a first partial sectional view of the venting element according to Fig. 3 in the area of ​​an entrance to an inner chamber of the electric machine according to Fig. 2, Fig. 6 a second partial sectional view of the venting element according to Fig. 3 in the area of ​​an entrance to an inner chamber of the electric machine according to Fig. 2, Fig. 7 a sectional view of the venting element according to Fig. 3 and Fig. 8 a sectional view of the venting element according to Fig. 3 with an alternative upper shell-shaped component,

[0021] Fig. Figure 1 shows an electric machine 1 that can be used to propel a motor vehicle (not shown). The electric machine 1 comprises, in particular, a machine housing 2, a stator 3, a rotor 4, and an output shaft 5 that can rotate about an axis of rotation R.

[0022] The machine housing 2 forms an interior space 6 within which the stator 3, the rotor 4, and the output shaft 5 are housed. The interior space 6 is enclosed. A lower part 6 uThe interior 6 is filled with oil 7, which is used to cool and / or lubricate components of the electric machine 1, e.g., to cool the stator 3 and the rotor 4. An upper part 6 o The interior space 6 is filled with air when the electric machine 1 is at rest. When the electric machine 1 heats up during operation, the oil 7 and the air also heat up. The air expands and increases the internal pressure p prevailing within the interior space 6. i In an external environment 9 of the electric machine 1, there is an external pressure p. a e.g. atmospheric pressure.

[0023] There is a need to equalize the pressure between the interior space 6, within which the higher internal pressure p exists. i prevails, and to create the external environment 9 within which the lower external pressure p a This is achieved by a venting element 10, which is Fig. Figures 2 to 8 are shown and described in more detail below. Furthermore, the output shaft 5 rotates during operation of the electric machine 1. This causes some of the oil 7 to become swirled, particularly in the upper part 6. o The electric machine forms an oil mist 8, i.e., finely atomized oil in the air. The oil mist 8, or its oil component, should not enter the external environment 9 of the electric machine 1 via the venting element 10. Conversely, no foreign matter from the external environment 9 should enter the interior 6 of the electric machine 1 via the venting element 10, in particular no dust, rainwater, water vapor, pressurized water, ice, or snow.

[0024] The venting element 10 has a collection chamber 11, an inlet 12, and, in the illustrated embodiment, a first outlet 13 and a second outlet 14. The inlet 12 of the venting element 11 is connected to the interior 6 of the machine housing 2. The first outlet 13 and the second inlet 14 of the venting element 10 are connected to the external environment 9 of the electric machine 1. The collection chamber 11 is arranged between the inlet 12 and the two outlets 13 and 14. The collection chamber 11 is connected to the interior 6 of the machine housing 2 via the inlet 12. The collection chamber 11 is connected to the external environment 9 of the electric machine 1 via the two outlets 13 and 14.

[0025] The feature "connected" is understood to mean, in particular, that the interconnected elements are conductively connected to one another in such a way that air can flow from one element to the other and, if applicable, vice versa, thus enabling pressure equalization between the interconnected elements. In the present embodiment, the venting element 10 connects the interior 6 of the machine housing 2 to the external environment 9 of the electric machine 1 in such a way that air escapes from the interior 6 into the external environment 9 via the inlet 12, the collection chamber 11, and the two outlets 13, 14 when the internal pressure p prevailing in the interior 6 i is higher than the prevailing external pressure p in the external environment 9 aForeign objects that may have entered the collection chamber 11 from the external environment 9 of the electric machine 1 are prevented by the venting element 10 from entering the interior 6 of the machine housing 2 via the inlet 12. Thus, the venting element 10 facilitates an outward flow of air from the interior 6 into the external environment 9, in order to maintain the internal pressure p during the operation of the electric machine 1. i to dismantle. At the same time, the ventilation element 10 prevents or at least makes it more difficult for foreign bodies (e.g. water or water vapor) from the external environment 9 to enter the interior space 6 in an inward direction.

[0026] The collection chamber 11 comprises an upper surface 15, a side surface 16, and a lower surface 17. The features "upper" and "lower" refer to a vertical direction y of the electric machine 1, and the feature "side" to a horizontal direction x (in which, for example, the axis of rotation R of the output shaft 5 may also run) of the electric machine 1. The upper surface 15, the side surface 16, and the lower surface 17 simultaneously form the outer surfaces of the venting element 10. The upper surface 15 and the side surface 16 are closed to the outside, i.e., towards the external environment 9. The collection chamber 11 is open only at the lower surface 17, namely in the areas of the first outlet 13 and the second outlet 14. In the area defined by Fig. In the embodiment shown in Figure 2, the two outlets 13, 14 are each arranged at an outer end section of a vertical tube 18, which projects downwards from the lower surface 17 in the vertical direction y and, in particular, is flush or level with an inner lower bottom 19 of the collection chamber 11. In this way, no foreign bodies 20 (e.g., water or steam) can penetrate the collection chamber 11 via the upper surface 15 and the side surface 16 and consequently cannot enter the interior 6 of the machine housing 2 via the inlet 12.

[0027] Foreign bodies 20 that may enter the collection chamber 11 via the first outlet 13 and / or the second outlet 14 do not enter the interior 6 of the machine housing 2 directly via the inlet 12. Instead, the foreign bodies 20 are first collected in the collection chamber 11. The collection chamber 11 is designed to be large-volume so that it can hold a particularly large quantity of foreign bodies 20, which can then collect in the collection chamber 11 instead of entering the interior 6 of the machine housing 2 via the inlet 12. In the illustrated embodiment, an interior chamber 23 of the collection chamber 11 has a volume greater than 10% of the oil volume 7 of the interior 6 to be vented.

[0028] The foreign bodies 20 can easily leave the collection chamber 11 via the two outlets 13, 14 by sinking under gravity towards the lower surface 17 or the bottom 19 and exiting the collection chamber 11 via the two vertical pipes 18 and the two outlets 13, 14. This is particularly possible if the foreign bodies 20 are small particles whose size is smaller than the diameter of the pipes 18. Liquid media such as water or the water content in water vapor can also easily sink under gravity within the collection chamber 11 towards the lower surface 17 or the bottom 19 and flow out of the collection chamber 11 via the two vertical pipes 18 and the two outlets 13, 14.

[0029] By providing the two outlets 13, 14 at spatially separated positions P1, P2 of the venting element 10, the electric machine 1 is made particularly resistant to cleaning with a water jet. In particular, water that has entered through the first outlet 13 can drain out through the second outlet 14, and vice versa. Specifically, the first outlet 13 is located at a first position P1 on the lower surface 17 of the collection chamber 11, while the second outlet 14 is located at a second position P2 on the lower surface 17 of the collection chamber 11. The first position P1 is located at a distance in the horizontal direction x from the second position P2. In the illustrated embodiment, the first position P1 is located at one end of the collection chamber 11 in the horizontal direction x, and the second position is located at the other end of the collection chamber 11.

[0030] An upper opening 30 of a labyrinth structure 33 of a funnel-shaped oil condensation element 29, described in more detail below, is connected to the inlet 12 to the interior 6 of the machine housing 2 and is located in the region of the upper surface 12, whereas the two outlets 13, 14 are located on the lower surface 17 of the collection chamber 11. Thus, the upper opening 30 of the labyrinth structure 33 is located vertically y above the two outlets 13, 14. This results in a height difference Δh between the upper opening 30 of the labyrinth structure 33 and the two outlets 13, 14. If, for example, water 20 enters the collection chamber 11, then the water must overcome this height difference Δh before it reaches the inlet 12 to the interior 6 of the machine housing 2 via the upper opening 30 of the labyrinth structure 33.Water 20 entering the collection chamber 11 will tend to flow out of the collection chamber 11 via one or both of the outlets 13, 14 rather than accumulating up to the level of the upper opening 30 of the labyrinth structure 33. Thus, large quantities, especially of splash water, can be collected within the collection chamber 11 and, due to the height difference Δh between the outlets 13, 14 and the upper opening 30 of the labyrinth structure 33, will only very rarely reach the interior 6 of the electric machine 1 via the inlet 12.

[0031] Fig. Figures 3 to 8 show details of a possible venting element 10 for the electric machine 1 according to Fig. 2. As from Fig. 7 and Fig. As can be seen in Figure 8, the collection chamber 11 can have several condensation surfaces 21 and several guide fins 22. The water content of water vapor that has entered the collection chamber 11 condenses on the condensation surfaces 21, with the condensed water flowing via the guide fins 22 to the two outlets 13, 14 ( Fig. 3) is directed and flows out of the collection chamber 11 via the two exits 13, 14.

[0032] Fig. 3, Fig. 4, Fig. 7 and Fig. Figure 8 shows that the venting element 10 can comprise a first shell-shaped component 24 and a second shell-shaped component 25, wherein the first shell-shaped component 24 and the second shell-shaped component 25 are detachably attached to one another and together form the collection chamber 11. In the illustrated embodiment, the first shell-shaped component 24 forms a lower part of the collection chamber 11, in which the two outlets 13, 14 are also arranged. The second shell-shaped component 25 forms an upper part of the collection chamber 11, in which the upper opening 30 of the labyrinth structure 33 of the funnel-shaped oil condensation element 29 is also arranged, the opening 30 being connected to the inlet 12 to the interior 6 of the machine housing 2. The first shell-shaped component 24 is in the embodiment shown by Fig. In the embodiment shown in Figure 7, the second shell-shaped component 25 is attached to the machine housing 2 of the electric machine 1. The second shell-shaped component 25 is attached to the first shell-shaped component 24.

[0033] The second shell-shaped component 25 can be according to Fig. 8 can be replaced by an alternative second shell-shaped component 25' to allow for differently sized chamber interiors 23, 23' of the collection chamber 11. The alternative second shell-shaped component 25' according to Fig. In the example shown, part 8 is larger than the second shell-shaped component 25. Fig. 7. Thus, the alternative chamber interior 23' also proves Fig. 8 a larger volume than the chamber interior 23 after Fig. 7.

[0034] Fig. Figure 4 shows that the attached vent, due to its special shape, can occupy unused spaces within the envelope of the electric machine 1.

[0035] In this arrangement, an upper part of the machine housing 2 has an outer surface 26 (enveloping contour) that forms an inwardly directed bulge 27. The venting element is arranged within the bulge 27 and attached to the machine housing 2 at this position.

[0036] Fig. 5, Fig. 6, Fig. 7 and Fig. Figure 8 shows that the venting element 10, in the area of ​​the inlet 12 leading to the interior 6 of the machine housing 2, can have a wire mesh plug 28 and a funnel-shaped oil condensation element 29 with an upper opening 30 and a lower opening 31 to cool any oil mist rising from the interior 6 and to discharge it back into the unit 1 via the funnel-shaped contour of the oil condensation element 29. Splashing oil and oil mist are thus returned to the unit 1 by this separation element 29 and do not enter the environment 9. The lower opening 31 is connected to the inlet 12 of the venting element 10. The upper opening 30, on the other hand, is connected to the collection chamber 11. The lower opening 31 has a smaller inner diameter than the upper opening 30. The wire mesh plug 28 is inserted into the upper opening 30 and is permeable to air.An oil mist penetrating from the interior 6 of the machine housing 2 into the funnel-shaped oil condensation element 29 cools down on an inner wall 32 of the funnel-shaped oil condensation element 29 and on the wire mesh plug 28, so that oil contained in the oil mist condenses, sinks by gravity and flows out into the interior 6 via the inlet 12 of the venting element 10.

[0037] Fig. 2, Fig. 5, Fig. 7 and Fig. Figure 8 shows that the venting element 10 can have a labyrinth structure 33. In particular Fig. Figure 5 shows that the labyrinth structure 33 in the illustrated embodiment comprises three sleeves 34 to 36 extending in the vertical direction y. An outer sleeve 34 radially surrounds a middle sleeve 35. The middle sleeve 35, in turn, radially surrounds an inner sleeve 36. In the illustrated embodiment, the radial direction of the sleeves 34 to 36 corresponds to the horizontal direction x. A labyrinth effect is achieved by the fact that, in the vertical direction y, a free end 37 of the outer sleeve 34 overlaps a free end 38 of the middle sleeve 35, and that, in the vertical direction y, a free end 39 of the inner sleeve 36 extends to the free end 38 of the middle sleeve 35.

[0038] The upper opening 30 of the funnel-shaped oil condensation element 29 forms an upper opening 30 of the labyrinth structure 33 and is connected to the collection chamber 11 via the labyrinth structure 33 (see Fig. 7 and Fig. 8), so that air can continue to flow between the opening and the collection chamber 11. However, dust particles not shown, which come from the external environment 9 via the two outlets 13, 14 (see Fig. 3) can enter the collection chamber 11, are prevented or at least hindered from reaching the wire mesh plug 28 via the labyrinth structure 33 and from accumulating on the wire mesh plug 28. In addition, the labyrinth structure 33 forms a further obstacle for oil from the interior 6 towards the external environment 9, so that it can be particularly reliably prevented that oil from the interior 6 of the machine housing 2 enters the environment 9. Reference sign Δh height difference p a External pressure p i Internal pressure P1 Position first exit P2 Position second exit R axis of rotation x horizontal direction y vertical direction 1 electric machine 2 machine housings 3 Stator 4 Rotor 5 Output shaft 6 Interior 6 o upper part of the interior 6 u lower part of the interior 7 Oil 8 Oil mist 9 external environment 10 venting element 11 Collection chamber 12 Entrance 13 first exit 14 second exit 15 upper surface 16 side surface 17 lower surface 18 pipe 19 inner lower floor 20 foreign bodies (water) 21 Condensation surfaces 22 guide ribs 23 Chamber interior 23' alternative chamber interior 24 first shell-shaped component 25 second shell-shaped component 25' alternative second shell-shaped component 26 outer surface machine housing 27 Bulge 28 wire mesh plugs 29 Oil condensation element 30 upper opening 31 lower opening 32 Inner wall oil condensation element 33 Labyrinth structure 34 outer sleeve 35 medium sleeve 36 inner sleeve 37 free-running end outer sleeve 38 free-running end middle sleeve 39 free-running end inner sleeve QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2003 / 0098204 A1

[0004] JP 2013-177952 A

[0005]

Claims

[1] Electric machine (1) for driving a motor vehicle, the electric machine (1) comprising - a machine housing (2) for accommodating a rotor (4), a stator (3) and an output shaft (5), and - a venting element (10) with a collecting chamber (11), with an inlet (12) and with at least one outlet (13, 14), wherein - the machine housing (2) forms an interior space (6) within which there is air which expands and creates an internal pressure (p i ) increases when the electrical machine (1) heats up during operation, - the inlet (12) of the venting element (10) is connected to the interior (6) of the machine housing (2), - the at least one outlet (13, 14) of the venting element (10) is connected to an external environment (9) of the electrical machine (1), - the collecting chamber (11) is arranged between the inlet (12) and the at least one outlet (13, 14) and is connected via the inlet (12) to the interior (6) of the machine housing (2) and via the at least one outlet (13, 14) to the external environment (9) of the electrical machine (1), - the venting element (10) connects the interior space (6) to the external environment (9) of the electrical machine (1) in such a way that air escapes from the interior space (6) via the inlet (12), the collecting chamber (11) and the at least one outlet (12, 14) into the external environment (9) when the internal pressure (p i ) is higher than the external pressure (p a ), and - the venting element (10) prevents foreign bodies (20) which have penetrated into the collecting chamber (11) from the external environment (9) of the electrical machine (1) from entering the interior (6) via the inlet (12). [2] Electrical machine (1) according to claim 1, wherein - the at least one outlet (13, 14) is arranged on a lower surface (17) of the collecting chamber (11), and - an upper surface (15) and a lateral surface (16) of the collecting chamber (11) are closed. [3] Electrical machine (1) according to claim 1 or 2, wherein the input (12) is arranged above the at least one output (13, 14). [4] Electrical machine (1) according to one of the preceding claims, wherein the collecting chamber (11) forms a chamber interior (23) whose volume is greater than 10% of the oil volume (7) in the interior (6). [5] Electrical machine (1) according to one of the preceding claims, wherein - the collecting chamber (11) has a condensation surface (21) and a guide rib (22), - Water from water vapor that has penetrated into the collecting chamber (11) condenses on the condensation surface (21), and - the condensed water is guided via the guide rib (22) to the at least one outlet (13, 14) and flows out of the collecting chamber (11) via the at least one outlet (13, 14). [6] Electrical machine (1) according to one of claims 2 to 5, wherein - a first outlet (13) is arranged at a first position (P1) on the lower surface (17) of the collecting chamber (11), - a second outlet (14) is arranged at a second position (P2) on the lower surface (17) of the collecting chamber (11), and - the first position (P1) is spaced from the second position (P2). [7] Electrical machine (1) according to one of the preceding claims, wherein - the venting element (10) comprises a first shell-shaped component (24) and a second shell-shaped component (25), and - the first shell-shaped component (24) and the second shell-shaped component (25) are detachably fastened to one another and together form the collecting chamber (11). [8] Electrical machine (1) according to claim 7, wherein one of the two shell-shaped components (25) can be replaced by an alternative shell-shaped component (25') with a different shape, so that a volume of the chamber interior (23 / 23') is changed. [9] Electrical machine (1) according to one of the preceding claims, wherein - an upper part of the machine housing (2) has an outer surface (26) which forms an inwardly directed bulge (27), and - the venting element (10) is arranged within the bulge (27). [10] Electrical machine (1) according to one of the preceding claims, wherein - the venting element (10) comprises a wire mesh plug (28) and a funnel-shaped oil condensation element (29) with an upper opening (30) and a lower opening (31), - the lower opening (31) is connected to the inlet (6) of the venting element (10), - the upper opening (30) is connected to the collecting chamber (11), - the lower opening (31) of the funnel-shaped oil condensation element (29) has a smaller inner diameter than the upper opening (30), - the wire mesh plug (28) is inserted into the upper opening (30), - the wire mesh plug (28) is permeable to air, and - an oil mist penetrating from the interior (6) of the machine housing (2) into the funnel-shaped oil condensation element (29) cools on an inner wall (32) of the funnel-shaped oil condensation element (29) and on the wire mesh plug (28), so that oil contained in the oil mist condenses, sinks by gravity and flows into the interior (6) via the inlet (12) of the venting element (10). [11] Electrical machine (1) according to claim 10, wherein - the venting element (10) has a labyrinth structure (33), and - the upper opening (30) of the funnel-shaped oil condensation element (29) is connected to the collecting chamber (11) via the labyrinth structure (33), so that dust particles which enter the collecting chamber (11) from the external environment (9) are prevented from reaching the wire mesh (28) via the labyrinth structure (33).

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