Axial flux machine

Abstract

Axial flux machines can be cooled by means of a coolant. The objective is to improve this cooling. The invention relates to an axial flux machine (1), having a stator (3) and a rotor (2) which can be rotated relative to the stator (3) about a rotational axis (A) and which has a rotor disc (4, 5) and a rotor face (6) arranged perpendicularly to the rotational axis (A), wherein the rotor (2) has at least one cooling structure (7) which is configured to convey a coolant (8) along the rotor face (6), wherein an outlet (10) of the at least one cooling structure (7) lies radially further towards the outside than an inlet (9) of the at least one cooling structure (7), wherein a radial coordinate of a progression of the at least one cooling structure (7) increases starting from the inlet (9) and then reduces again at least in some regions towards the outlet (10). The at least one cooling structure (7) is designed to this end as two concentric spirals, the radially outer ends of which are connected to one another and the radially inner ends of which constitute the inlet and the outlet.

Description

[0001] axial flux machine

[0002] The invention relates to an axial flux machine comprising a stator and a rotor rotatable about an axis of rotation relative to the stator, with a rotor disk and a rotor surface arranged perpendicular to the axis of rotation.

[0003] Electrical machines with a rotor and a stator are common. During operation, the electrical machine heats up due to losses. These can be divided into ohmic losses, iron losses, stray losses, and mechanical losses. Iron losses occur primarily in the stator and rotor and contribute significantly to the total losses. If the electrical machine heats up too much, it can be destroyed. Therefore, various cooling systems are known in the state of the art.

[0004] For example, the generic document JP 3 938 572 B2 shows a superconducting synchronous machine with a rotor on a shaft, with the superconductor attached to the rotor and generating a magnetic field. The rotor and the shaft have coolant channels, with the coolant channels in the shaft connecting to a coolant source and supplying the coolant channels in the rotor with coolant. The coolant channels in the rotor have an inlet area where they can be flooded with coolant, then extend along the superconductor and end in an outlet area, from which the coolant then flows back into the coolant channels of the shaft and is discharged to the outside.

[0005] DE 102020 101 979 A1 discloses a liquid-cooled axial-flow motor with a stator and a rotor on a rotor shaft. Here, too, the rotor shaft includes an axial coolant channel with an inlet and an outlet. The rotor includes coolant channels that extend radially from the rotor shaft and have an inlet in fluid communication with the outlet of the axial coolant channel of the shaft. The radial coolant channel of the rotor terminates at the radially outer end of the rotor with an outlet, with the coolant flowing into an inlet of a housing-mounted coolant distribution head. An outlet of the coolant distribution head is arranged above the stator in axial overlap, and the inlet of the coolant collection head is arranged below the stator with respect to the direction of gravity.

[0006] In addition, JP 2011 - 130 530 A, for example, shows a rotor of an axial flux motor consisting of a plurality of magnets in a laminated core. The laminated core is formed from a strip-shaped electromagnetic sheet wound spirally. Recesses are punched into the sheet metal strip, which, when wound spirally, form pockets for accommodating the magnets. Between the recesses in the sheet metal strip forming the magnet pockets, further recesses are punched out, which, when wound, form radial cooling channels between the magnets.

[0007] The invention is based on the object of providing improved cooling for an axial flow machine, in particular a rotor of the axial flow machine.

[0008] The problem is solved by the subject matter of the independent patent claims. Advantageous developments of the invention are described by the dependent patent claims, the following description, and the figures.

[0009] The invention is based on the idea of ​​improving the cooling of the axial flow machine by a targeted radial back and forth flow of a coolant along a rotor surface.

[0010] One aspect of the invention relates to an axial flux machine. The axial flux machine has a stator and a rotor. The rotor is rotatable about an axis of rotation relative to the stator. The rotor has a rotor disk and a rotor surface of the rotor disk arranged perpendicular to the axis of rotation. The rotor has at least one cooling structure which is designed to guide a coolant along the rotor surface. The at least one cooling structure has an inlet and an outlet. The outlet of the at least one cooling structure is located radially further outwards than the inlet of the at least one cooling structure. A radial coordinate of a profile of the at least one cooling structure increases starting from the inlet and then decreases again at least in regions towards the outlet. The profile of the at least one cooling structure therefore moves away from the inlet and away from the axis of rotation and then approaches the axis of rotation again at least in regions towards the outlet.By specifically guiding the coolant flow across the rotor surface from the inlet to the outlet using the cooling structure, convective heat transfer between the rotor and the coolant can be improved. This enables a defined heat exchange from the rotor to the coolant. Furthermore, the rotor is cooled particularly evenly, as the coolant flows from the inlet through the cooling structure, initially radially outward and then radially inward again to the outlet. This causes already heated coolant to flow radially inward through the rotor, and still cool coolant to flow radially outward. The rotor surface can also be referred to as the rotor backside or rotor disk surface.

[0011] With a purely radial outward flow of the coolant, the rotor would be cooled very unevenly radially, namely, less and less with increasing radius. As a result, the effectiveness of rotor cooling can be significantly improved by the cooling structure with radial back-and-forth flow, which can enable an increase in the continuous power of the electric machine and / or the use of more cost-effective magnetic materials, adhesives, and the like. This is particularly possible because the improved cooling of the rotor leads to a lower temperature of the rotor magnets and the adhesives, thus lowering the temperature requirements for the magnetic materials and adhesives.

[0012] According to the invention, the at least one cooling structure is designed as two nested spirals. Radially outer ends of the spirals are connected to each other. Radially inner ends of the spirals represent the inlet and the outlet. The at least one cooling structure thus has at least one loop. This results, for example, in a kind of meander. This shape of the at least one cooling structure allows the coolant to be guided radially outward and then, at least in some areas, radially inward to the outlet. This ensures particularly even cooling of the rotor.

[0013] In particular, the rotor surface is arranged perpendicular to the axis of rotation. The normal direction with respect to the rotor surface thus runs parallel to the axis of rotation. In particular, the vertical rotor surface is cooled and not necessarily a lateral surface of the rotor. This is particularly advantageous for axial flux machines, in which most of the heat is generated at the rotor surface. In some embodiments, the rotor surface is located in the axial direction on a side of the rotor disks facing away from the stator. When reference is made to an axial or radial direction in this document, this is always to be understood in relation to the axis of rotation of the rotor, unless otherwise stated.

[0014] The coolant is primarily a lubricating oil for the bearings of the electric machine. Optionally, the coolant is a specific cooling oil.

[0015] The axial flux machine is an axially constructed electrical machine, for example in which a stator disk is arranged sandwiched between two rotor disks. In particular, the stator disk is arranged on only one rotor disk. In the axial flux machine, the magnetic flux flows parallel to the axis of rotation of the rotor. Therefore, the heat development in the axial flux machine on the rotor surface which is perpendicular to the axis of rotation is greater than in a radial flux machine. In a radial flux machine, more heat is generated on a lateral surface of the rotor. The rotor arrangement according to the invention is therefore particularly advantageous for axial flux machines. In particular, the rotor surface is a side of the rotor facing away from the stator. If there are two rotor disks, then in particular there are exactly two rotor surfaces, each located on a rotor disk.

[0016] In one embodiment, the rotor comprises a first rotor disk and a second rotor disk, which are connected in a rotationally fixed manner via an axis, so that the rotor has an H-shape in longitudinal section. The cooling structure is arranged at least on and / or in the first rotor disk. However, it is also possible for a cooling structure to be arranged on and / or in both the first rotor disk and the second rotor disk.

[0017] For example, the respective rotor disk is a magnet carrier. This means in particular that respective magnets, in particular permanent magnets, can be held on the respective rotor disk, so that the respective magnets are carried by the respective rotor disk. Thus, the respective magnets can rotate with the respective rotor disk, on which the respective magnets are held, about the axis of rotation relative to the stator. Furthermore, it is conceivable that at least one or more coils are held on the stator. The coil can be energized. This means that an electric current can flow through the coil. Thus, for example, the stator carries the coil. In particular, the axial flux machine can have a housing, wherein the rotor disks can be rotated about the machine axis of rotation relative to the housing. In this case, it is provided in particular that the stator is fixed to the housing. This means that the stator is connected to the housing in a rotationally fixed manner.Since the stator is arranged between the rotor disks in the axial direction of the axial flux machine, the stator is also referred to as the central stator. In particular, by energizing the coil, i.e., by passing an electric current through the coil(s), the rotor disks can be driven and thus rotated, in particular about the rotational axis, relative to the stator and preferably also relative to the housing.

[0018] Furthermore, it is preferably provided that a first air gap is arranged in the axial direction of the axial flux machine between the stator and a first of the rotor disks. Furthermore, it is preferably provided that a second air gap is arranged in the axial direction of the axial flux machine between the stator and a second of the rotor disks. In particular, the respective air gap can be at least substantially disk-shaped.

[0019] In one embodiment, the cooling structure is designed as a single, continuous cooling channel. This creates a single, homogeneous cooling flow. This allows the rotor surface to be cooled particularly evenly.

[0020] Alternatively, the cooling structure can also be provided and arranged multiple times in the rotor, in particular in the same way, so that each of the multiple cooling structures has the same shape.

[0021] In one embodiment, the cooling structure runs within the rotor disk. The cooling structure is thus incorporated into a material of the rotor disk.

[0022] For example, through groove-like recesses in the rotor disk. This saves space and weight. In particular, the cooling structure runs entirely within the rotor disk.

[0023] In one embodiment, the axial flow machine has a housing with a hollow structure. The axial flow machine is designed such that the coolant flows contactlessly from the outlet of the cooling structure into the hollow structure. Preferably, the hollow structure is fluidly connected to the outlet, in particular only at a housing surface that is arranged substantially parallel to the rotor surface and faces the rotor surface. For example, the coolant enters the cooling structure from a rotor shaft of the rotor. In particular, after the coolant leaves the cooling structure, the coolant flows into the hollow structure through inlet openings of the hollow structure, possibly due to gravity. Optionally, the coolant is guided through the hollow structure, in particular by means of a pump, back into a rotor shaft of the rotor. Preferably, the axial flow machine is designed such that the coolant can flow in this circuit.

[0024] In particular, this embodiment eliminates the need for a tray to collect the coolant. This reduces drag losses because the rotor is not slowed down by the coolant in a tray, and / or saves installation space because no tray is required.

[0025] Non-contact means in particular that no seals or rotary unions are required to transport the coolant into the hollow structure, thus also reducing losses in the axial flow machine.

[0026] In one embodiment, the axial flux machine has a rotor cover separate from the rotor disk. The rotor cover axially encloses the cooling structure on a side facing away from the stator. This side facing away from the stator can be referred to, in particular, as the outer side of the rotor, and a side facing the stator can be referred to, in particular, as the magnet side of the rotor.

[0027] If necessary, the outlet faces the rotor cover and the inlet faces the magnet side. For example, the cooling structure is arranged in a groove-like manner in the rotor disk and is axially open on the outside. The cooling structure is closed off on the outside by the rotor cover.

[0028] In one embodiment, an axial flux machine has a rotor cover separate from the rotor disk. The cooling structure runs within the rotor cover. For example, the cooling structure runs entirely within the rotor cover. In this case, the rotor disk preferably encloses the cooling structure in the axial direction. Optionally, the cooling structure runs partially within the rotor cover and partially within the rotor disk. Optionally, the cooling structure has a first half-channel in the rotor cover and a second half-channel in the rotor disk.

[0029] In one embodiment, the rotor cover has an outlet portion. The outlet portion is raised from the rotor surface in the axial direction. The axial distance from the rotor surface increases with decreasing radius relative to the rotational axis. The outlet portion is open toward the rotational axis. The outlet portion is a portion of the rotor cover arranged closest to the rotational axis in the radial direction. The outlet portion is further away from the rotational axis in the radial direction than the inlet of the cooling structure.

[0030] In particular, the outlet part is designed to be completely circumferential with respect to the axis of rotation, in particular in order to guide the coolant into the hollow structure.

[0031] In one embodiment, the outlet section is funnel-shaped. This means, in particular, that the outlet section protrudes from the rotor surface in the longitudinal section through the rotational axis. This shape is particularly suitable for guiding the coolant into the hollow structure due to a corresponding protrusion angle. In particular, the protrusion angle relative to the rotor surface is between 10° and 80°, in particular between 40° and 60°.

[0032] In one embodiment, the housing has a catch part. The catch part is raised in the axial direction from a housing surface facing the rotor surface. The axial distance from the housing surface increases with decreasing radius relative to the axis of rotation. The catch part is open toward the axis of rotation. The catch part overlaps at least partially with the opening of the rotor cover in the radial direction.

[0033] In particular, the catching part is designed to be completely circumferential with respect to the axis of rotation in order to prevent the coolant from flowing past the outside of the catching part instead of into the hollow structure.

[0034] In particular, the capture part is funnel-shaped. This means that the capture part protrudes from the housing surface in the longitudinal section through the axis of rotation. This shape is particularly suitable for capturing the coolant and, in particular, for guiding it further into the hollow structure. In particular, the protrusion angle of the capture part in relation to the housing surface is between 10° and 80°, in particular between 40° and 60°. For example, only a region of the capture part that overlaps with the outlet part is funnel-shaped. Optionally, the capture part is V-shaped or Z-shaped, with a first leg of the shape being arranged directly along the housing on the housing surface, which is arranged essentially parallel to the rotor surface and faces the rotor surface. Preferably, a second and / or a third leg of the shape forms the funnel-shaped, overlapping region.

[0035] In one embodiment, the rotor shaft has a hollow space. The hollow space is fluidly connected to the cooling structure via the inlet for feeding the coolant into the cooling structure. The axial flow machine is designed such that the coolant can be injected, in particular is injected, into the hollow space of the rotor shaft without contact, in particular from the hollow structure.

[0036] For this purpose, the axial-flow machine has, for example, a spray tube. Preferably, the axial-flow machine has a pump that can transport the coolant from the hollow structure of the housing via the spray tube into the rotor shaft.

[0037] Another aspect of the invention relates to a vehicle with an axial flux machine according to the invention. The axial flux machine is designed to drive the vehicle as part of an electric drive train of the vehicle.

[0038] In particular, the axial flux machine is a component of the electric drive train, for example, of a motor vehicle, that provides drive torque. This means that the axial flux machine, also known as a disc rotor machine, can be used for a drive train of a motor vehicle, so that the motor vehicle can be driven, in particular purely electrically, by means of the axial flux machine. Thus, the axial flux machine is, in particular, a traction machine by means of which the motor vehicle can be driven, in particular purely electrically. The motor vehicle is thus, for example, a hybrid vehicle or an electric vehicle, in particular a battery-electric vehicle (BEV).

[0039] Further embodiments of the vehicle according to the invention follow directly from the various embodiments of the axial flux machine according to the invention, and vice versa. In particular, individual features and corresponding explanations as well as advantages relating to the various embodiments of the axial flux machine according to the invention can be transferred analogously to corresponding embodiments of the vehicle according to the invention, and vice versa.

[0040] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combinations, but also in other combinations or on their own, without departing from the scope of the invention.

[0041] Showing:

[0042] Fig. 1 shows a partial schematic longitudinal sectional view of an embodiment of an axial flow machine according to the invention;

[0043] Fig. 2 shows a partial schematic cross-sectional view of a further embodiment of an axial flow machine according to the invention; and

[0044] Fig. 3 shows a partial schematic longitudinal sectional view of a further embodiment of an axial flow machine according to the invention.

[0045] Fig. 1 shows a detail of a schematic longitudinal sectional view of an embodiment of an axial flux machine 1. The axial flux machine 1 can also be referred to as a disc rotor machine. In particular, the axial flux machine 1 is an axial flux machine for a motor vehicle. This means, for example, that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, can have the axial flux machine 1 in its fully manufactured state. The axial flux machine 1 is an electrical machine which can provide torque. In particular, vehicle wheels of an axle of the motor vehicle can be driven by means of the respective torque provided by the axial flux machine 1, whereby the motor vehicle can be driven, in particular purely electrically.

[0046] The axial flux machine 1 has a rotor 2 and a stator 3 (Fig. 3). The rotor 2 has, in particular, a first rotor disk 4 and a second rotor disk 5 (Fig. 3). The rotor disks 4, 5 are rotatable, in particular jointly or simultaneously, about a machine rotation axis, also simply referred to as the rotation axis A, relative to the stator 3. In particular, the axial flux machine 1 can provide the aforementioned torques via the rotor 2. The rotation axis A is, for example, an axis of symmetry, with respect to which, for example, the respective rotor disk 4, 5 and / or the stator 3 is rotationally symmetrical. In addition, the rotation axis A is also referred to as the rotation axis, since the rotor disks 4, 5 and the rotation axis are rotatable relative to the stator 3. In particular, the stator 3 is arranged between the rotor disks 4, 5 in the axial direction of the axial flux machine 1.

[0047] The rotor 2 has a rotor surface 6 arranged perpendicular to the axis of rotation. In this exemplary embodiment, the rotor 2 has a cooling structure 7 configured to guide a coolant 8 (Fig. 3) along the rotor surface 6. The cooling structure 7 has an inlet 9 and an outlet 10. The outlet 10 of the cooling structure 7 is located radially further outward than the inlet 9 of the cooling structure 7. The cooling structure 7 extends radially outward from the inlet 9 and then, at least in some regions, radially inward to the outlet 10.

[0048] Alternatively, in an embodiment not shown, the cooling structure can be provided and arranged multiple times in the rotor. These can then, for example, be of the same type, so that each of the multiple cooling structures has the same shape. Different shapes of the multiple cooling structures are also fundamentally possible, although this is not necessarily recommended due to the otherwise rotationally symmetrical design of the rotor, as this could result in different cooling effects.

[0049] In the embodiment shown in Fig. 1, the rotor 2 has a rotor cover 11. For example, the first rotor disk 4 and / or the second rotor disk 5 has the cooling structure 7. In other embodiments not shown here, the rotor cover 11 may have the cooling structure 7.

[0050] The rotor cover 11 preferably has an outlet part 11a. The outlet part 11a is optionally funnel-shaped and protrudes in particular from the rotor surface 6 in the axial direction.

[0051] Fig. 2 shows a schematic cross-sectional view of another

[0052] Embodiment of the axial flow machine 1. For example, the first rotor disk 4 or the second rotor disk 5 is shown in Fig. 2. For example, the first rotor disk 4 is shown in an axial plan view of the cooling structure 7 without the rotor cover 11 in Fig. 2.

[0053] For example, the cooling structure 7 has a cooling channel 7c and a passage 7d. The passage 7d leads from a collecting basin 15a (Fig. 3) inside a rotor shaft 15 (Fig. 3) of the rotor 2 axially away from the stator 3 and radially outward to the cooling channel 7c.

[0054] A side facing the stator 3 can in particular be referred to as the magnet side. In particular, the first rotor disk 4 has a first magnet side, and the second rotor disk 5 has a second magnet side. If appropriate, the respective opposite side can be referred to as the first outer side of the first rotor disk 4 and the second outer side of the second rotor disk 5. In particular, the respective outer side corresponds to the respective rotor surface 6. In the exemplary plan view of Fig. 2, the passage 7d to the first outer side is at least partially concealed. The passage 7d preferably leads from the collecting basin 15a from the magnet side to the outer side of the respective rotor disk 4, 5.

[0055] For example, the cooling channel 7c extends from the passage 7d, in particular in a spiral or helical shape, radially outward, in particular to a turning loop 7a. This can be referred to, for example, as meandering. Preferably, the cooling structure 7 extends from the turning loop 7a, in particular in a helical shape, radially inward to the outlet 10. Preferably, the cooling structure 7 is as round as possible. This means, in particular, that a radius of the helical cooling structure 7 increases uniformly. A change in the radius of the cooling structure 7 can therefore, for example, be constant, with the exception of the turning loop 7a.

[0056] In other embodiments not shown, the cooling structure has several turning loops 7a.

[0057] Preferably, a width 7b of the cooling structure 7 is between 1 mm and 4 mm, in particular between 2 mm and 3 mm, in particular 2.5 mm. Preferably, an axial depth of the cooling structure 7 is between 1 mm and 4 mm, in particular between 1.5 mm and 2.5 mm, in particular 2 mm. Fig. 3 shows a detail of a schematic longitudinal sectional view of a further embodiment of the axial flux machine 1. The axial flux machine 1 has, for example, a housing 12. For example, the housing 12 encloses an interior space 1a of the axial flux machine. If appropriate, the stator 3 and the rotor disks 4, 5 are each arranged at least partially, in particular completely, in the interior space 1a. The stator 3 is preferably mounted fixedly to the housing, i.e., connected to the housing 12 in a rotationally fixed manner. In particular, the rotor disks 4, 5 are rotatable about the axis of rotation A relative to the housing 12 and relative to the stator 3.For example, magnets 13, 14 are held on the rotor disks 4, 5, in particular such that the rotor disks 4, 5 each at least partially accommodate the magnets 13, 14. In particular, the magnets 13 and 14 are designed as permanent magnets. For example, the rotor 2 has the rotor shaft 15. The rotor shaft 15 runs in particular parallel to the axis of rotation A.

[0058] The housing 12 preferably has a hollow structure 12a, not shown in full in Fig. 3. The hollow structure 12a has, in particular, an opening 12b into the interior 1a of the axial flow machine 1. For example, the opening 12b is arranged on a side part 12c of the housing 12. The side part 12c is preferably arranged perpendicular to the axis of rotation A and, in particular, has a housing surface facing the rotor disk 4, 5. It is possible for the hollow structure to have a plurality of openings 12b. For example, the hollow structure 12a extends radially outwards in a tube-like or shaft-like manner, in particular in the side part 12c. For example, the housing 12 has a shell part 12d. The hollow structure 12a preferably runs, in particular additionally, in the shell part 12d. In particular, the hollow structure 12a runs in a region of the shell part 12d which, when the axial flow machine 1 is installed as intended, is located at the bottom.

[0059] Optionally, the housing 12 has a catch part 12e. The catch part 12e may be funnel-shaped and protrudes axially from the side part 12c. For example, the catch part 12e and the outlet part 11a overlap radially. In particular, the outlet part 11a is arranged at least partially radially further inward than the catch part 12e.

[0060] A circuit for the coolant 8 can be configured, for example, as follows. The coolant 8 can, for example, pass from the rotor shaft 15 through the passage 7d into the cooling channel 7c. In the cooling channel 7c, the coolant is preferably first guided radially outward, in particular to the turning loop 7a, and then radially inward again to the outlet 10. From the outlet 10, the coolant 8 reaches the collecting part 12e, in particular via the outlet part 11a. The collecting part 12e optionally guides the coolant through the opening 12b into the hollow structure 12a, through the side part 12c, and optionally into the casing part 12d.

[0061] Preferably, a pump (not shown in Fig. 3) pumps the coolant 8 from the hollow structure 12a, in particular from the casing part 12d, into the rotor shaft 15. Optionally, the axial flow machine 1 has a spray tube 16. Optionally, the coolant 8 is sprayed into the rotor shaft 15 via the spray tube 16. Preferably, the rotor shaft 15 has a funnel-shaped collecting part 15a. The collecting part 15a protrudes, in particular, radially inward from the rotor shaft 15 and directs the coolant 8 axially toward the inlet 9.

[0062] In the embodiment shown in Fig. 3, the axial flux machine 1 has a planetary gear 17. For example, the coolant 8 is guided from the hollow structure 12a through a rotary union 19 into an output shaft 17a of the planetary gear 17. For example, the coolant 8 is then sprayed from the output shaft 17a via the spray tube 16 into the rotor shaft 15.

[0063] Optionally, the rotor shaft 15 is designed as a differential shaft and the coolant 8 enters the inlet 9 through the differential shaft. In other embodiments not shown, the axial flux machine 1 has a spur gear pair, in particular instead of the planetary gear 17.

[0064] List of reference symbols

[0065] 1 axial flux machine

[0066] 1a interior

[0067] 2 rotors

[0068] 3 Stator

[0069] 4 First rotor disc

[0070] 5 Second rotor disc

[0071] 6 Rotor area

[0072] 7 Cool Structure

[0073] 7a Turning loop

[0074] 7b Width

[0075] 7c Cooling channel

[0076] 7d Implementation

[0077] 8 Coolant

[0078] 9 Entrance

[0079] 10 Outlet

[0080] 11 Rotor cover

[0081] 11a Outlet part

[0082] 12 housings

[0083] 12a Hollow structure

[0084] 12b Opening

[0085] 12c side panel

[0086] 12d shell part

[0087] 12th catch part

[0088] 13 Magnet

[0089] 14 Magnet

[0090] 15 Rotor shaft

[0091] 15a Collective section

[0092] 16 spray tubes

[0093] 17 planetary gears

Claims

Patent claims 1. An axial flux machine (1) comprising a stator (3) and a rotor (2) rotatable about an axis of rotation (A) relative to the stator (3), said rotor having a rotor disk (4, 5) and a rotor surface (6) of the rotor disk (4, 5) arranged perpendicular to the axis of rotation (A), wherein the rotor (2) has at least one cooling structure (7) configured to guide a coolant (8) along the rotor surface (6); an outlet (10) of the at least one cooling structure (7) is located radially further outward than an inlet (9) of the at least one cooling structure (7); and a radial coordinate of a profile of the at least one cooling structure (7) increases starting from the inlet (9) and then decreases again, at least in regions, towards the outlet (10), characterized in that the at least one cooling structure (7) is designed as two nested spirals, the radially outer ends of which are connected to one another and the radially inner ends of which represent the inlet and the outlet.

2. Axial flow machine (1) according to claim 1, characterized in that the at least one cooling structure (7) runs within the rotor disk (4, 5) of the rotor (2).

3. Axial flow machine (1) according to claim 1 or 2, characterized in that the axial flow machine (1) has a housing (12) with a hollow structure (12a), and the axial flow machine (1) is designed such that the coolant (8) flows from the outlet (10) of the at least one cooling structure (7) into the hollow structure (12a) without contact.

4. Axial flux machine (1) according to one of the preceding claims, characterized in that the axial flux machine (1) has a rotor cover (11) which is separate from the rotor disk (4, 5) and which axially closes off the at least one cooling structure (7) on a side facing away from the stator (3).

5. Axial flux machine (1) according to one of claims 1 to 3, characterized in that the axial flux machine (1) has a rotor cover (11) separate from the rotor disk (4, 5), wherein the at least one cooling structure (7) runs within the rotor cover (11).

6. Axial flow machine (1) according to claim 4 or 5, characterized in that the rotor cover (11) has an outlet part (11a), wherein the outlet part (11a): is raised in the axial direction from the rotor surface (6), wherein an axial distance from the rotor surface (6) increases with decreasing radius with respect to the axis of rotation (A), is open towards the axis of rotation (A) and has a corresponding opening (12b), is a part of the rotor cover (11) arranged closest to the axis of rotation (A) in the radial direction, and is further away from the axis of rotation (A) in the radial direction than the inlet (9) of the at least one cooling structure (7).

7. Axial flow machine (1) according to claim 3 and claim 6, characterized in that the housing (12) has a catch part (12e), wherein the catch part (12e): is raised in the axial direction from a housing surface of the housing (12) facing the rotor surface (6), wherein an axial distance from the housing surface increases with decreasing radius with respect to the axis of rotation (A), is open towards the axis of rotation (A), and in the radial direction at least partially overlaps with the opening (12b) of the rotor cover (11).

8. Axial flow machine (1) according to one of the preceding claims, characterized in that the rotor shaft (15) has a cavity which is used to feed the coolant (8) is fluidically connected to the at least one cooling structure (7) via the inlet (9), and the axial flow machine (1) is designed such that the coolant (8) is sprayed into the cavity of the rotor shaft (15) in a contactless manner during operation, in particular from the hollow structure (12a).

9. Vehicle with an axial flux machine (1) according to one of the preceding claims, wherein the axial flux machine (1) is designed to drive the vehicle as part of an electric drive train of the vehicle.

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