Housing for a stator of an electric machine

Abstract

The invention describes a housing (2) for a stator (4) of an electric machine (6), wherein the housing (2) comprises a stator core (10), stator core rods (12) and a flange (14). The stator core (10) is connected to the flange (14) via the stator core rods (12) and the stator core rods (12) adjoin the flange (14). The invention also describes a stator (4) of an electric machine (6) having such a housing (2) and an electric machine (6) having such a stator (4).

Description

[0001] Housing for a stator of an electrical machine

[0002] Technical area

[0003] The present invention relates to a housing for a stator of an electrical machine. Furthermore, the present invention relates to a stator of an electrical machine having such a housing. Furthermore, the present invention relates to an electrical machine having such a stator.

[0004] State of the art

[0005] Housings for generator stators are known from the state of the art. When the generator is in use, heat is generated due to the current flow in the stator's electrical wires. In order to increase the current flow and thus the generator's power, this generated heat must be dissipated.

[0006] US 2022 / 0200371 A1 describes how the heat generated in the stator can be dissipated using oil cooling. Alternatively, it is known that the heat generated can be dissipated using air cooling.

[0007] Description of the invention

[0008] In a first aspect, the present invention relates to a housing for a stator of an electrical machine. The housing can comprise the stator. The housing can enclose the stator. The housing can be cylindrical. The housing can enclose electrical lines of the stator. The housing can serve to provide mechanical stability to the stator. The electrical machine can be, for example, an electric motor or a generator.

[0009] The housing has a stator core, stator core bars, and a flange. The housing can have exactly one or more flanges. The flange can be used for the modular connection of the housing, and thus of the electrical machine, to other elements, such as a gearbox. The stator core can consist of layers and, alternatively or additionally, of stacks of a material, such as steel. The layers or stacks can be connected to one another, for example, welded together. The stator core bars can be bars that connect the stator core to one another and hold the stator core together. For example, the layers of the stator core can be held together by means of the stator core bars. For example, the stator core bars can be welded to the layers of the stator core. The housing can have multiple stator core bars, for example, 6, 8, 10, or 12.The stator core bars may be arranged along a circumference of the stator core such that individual stator core bars are spaced apart from one another and run parallel to one another.

[0010] The stator core is connected to the flange via the stator core bars. The stator core can be connected to the flange solely, alternatively or additionally, primarily mechanically via the stator core bars for transmitting force. Force transmission between the stator core and the flange can, for example, occur partially or completely via the stator core bars. The stator core bars are connected to the flange. For example, the stator core bars are connected directly to the flange, i.e., they are directly connected to the flange. For example, the stator core bars are screwed to the flange and, alternatively or additionally, welded. There can be a direct connection between the flange and the stator core bars, and between the stator core bars and the stator core.

[0011] By connecting the stator core to the flange via stator core bars, better power transmission of the housing can be achieved. The stator core bars can transmit all or at least a large portion of the force between the stator core and the flange. Any outer wall of the housing does not have to be designed to transmit power between the flange and stator core. This means that such an outer wall can be made thinner and therefore lighter. This saves material and weight. However, by connecting the flange and stator core via stator core bars, the housing can be constructed more rigidly, with the stability and rigidity of the stator core bars ensuring the stability and rigidity of the housing. Stator core bars, which may be necessary to connect the layers of the stator core, can also be used to increase the stability and rigidity of the housing.Any outer wall can be connected to the stator core bars to further increase the rigidity and stability of the housing.

[0012] According to a further embodiment, the housing can be characterized in that the housing can have an axial direction. The stator core bars can run in the axial direction. The housing can have end plates, for example, the housing can have two end plates. The end plates can delimit the stator core in the axial direction. By means of the end plates, which are connected to the stator core bars, for example by welded joints, a uniform clamping force can be exerted by the stator core bars on the layers of the stator core. The end plates can also be fastened, for example, to an outer wall of the housing, for example by screws or welded joints. Furthermore, stator core bars can protrude in the axial direction beyond at least one end plate and the stator core.For example, some or all of the stator core bars may extend beyond an end plate and the stator core on one side, thus extending axially on one side. Alternatively, some or all of the stator core bars may extend axially beyond both end plates and the stator core on both sides. For example, if the stator core bars extend beyond both sides, they may extend beyond the end plates and the stator core by the same or different lengths. The end plates may have recesses through which a stator core bar can extend.

[0013] Because the stator core bars project axially beyond the end plate and the stator core, the flange can be connected directly to the stator core via the stator core bars. The flange can be arranged axially offset from the stator core. Additional elements for connecting the flange and stator core are not necessary. Connecting the stator core and flange via an outer wall, where the outer wall primarily contributes to the force transmission between the stator core and the flange, is therefore no longer necessary. This means that the outer wall does not have to be designed to transmit the dead weight of the stator and the housing as well as forces. This enables a lighter construction and higher forces on the stator and the electrical machine.

[0014] According to a further embodiment, the housing can be characterized in that an element can connect to stator core bars, wherein the element is connectable to a mechanical brake of the electrical machine. The mechanical brake, for example a brake caliper of the brake, can connect to some or all of the stator core bars via the element. Alternatively, the mechanical brake can connect directly to stator core bars, and in such an embodiment, the stator core bars can, for example, protrude through the element. A brake disc of the brake can be attached to the rotor of the electrical machine. The element can be a generator cover or end cover. The element can be a flange to which a generator cover, end cover, or the brake caliper can be connectable.For example, the flange may be arranged at one end of the stator core bars, and such an element may be arranged at the other end of the stator core bars.

[0015] This allows a mechanical brake to be connected to the housing in a particularly stable design. This allows a mechanical brake to be provided for the electric machine without requiring any further design changes to the housing or the electric machine.

[0016] According to a further embodiment, the housing can be characterized in that the housing can have channels for a cooling liquid. The cooling liquid can be water or oil, for example. Channels can be tubes, for example straight or bent tubes. The flange can have a first opening and a second opening, for example the flange can have exactly one first and one second opening. Alternatively, the flange can have more than the first and second openings. The openings and the channels can, for example, have similar or identical diameters, for example similar or identical inner diameters. Alternatively, parts of the channels and the openings can have different inner diameters than the other channels or openings. Channels, for example some of the channels of the housing, can run through the stator core. Holes can be provided in the layers of the stator core, for example by punching.The stator core, consisting of the layers, can form the channels in the stator core by arranging the layers with the holes next to one another. The layers of the stator core can, for example, be bonded together to ensure that the channels in the stator core are liquid-tight. The channels can provide a fluid connection from the first opening to the second opening. For example, all channels of the housing can provide a fluid connection from the first opening to the second opening. Via the fluid connection, a fluid that enters the housing and the channels through the first opening can pass through the channels and exits the channels and the housing again through the second opening.

[0017] This makes it possible to cool the stator core with a coolant. A cooler located outside the housing can cool the coolant. Furthermore, a pump located outside the housing can pump the coolant through the openings and channels. This allows heat to be transported out of the housing and away from the stator. By cooling the housing and the stator core, a higher current density can be achieved through the stator wires. This allows a higher torque density of the electrical machine to be achieved. This can increase the efficiency of the electrical machine in relation to the spatial expansion of the electrical machine. By cooling the stator core, cooling can take place spatially close to the stator itself and thus to the electrical wires and therefore to the heat source.This ensures effective heat transfer and heat transport between the stator and the cooling liquid, as heat transport between the heat source and the cooling liquid is not necessary through the entire stator core and possibly other elements. Cooling the stator makes cooling the rotor optional, for example because cooling the stator can be more efficient than cooling the rotor. Furthermore, the channels running through the stator core avoid the need for complex pipes that can be attached outside the stator core and to the housing. By providing the fluid connection, the cooling liquid can be restricted to a specific spatial section of the housing. This protects certain elements of the housing and the electrical machine from the cooling liquid and from direct contact with the cooling liquid.This eliminates the need for open cooling with, for example, oil. This allows such a housing to be combined with additional air cooling, for example for the rotor of the electric motor. It also increases the safety of the housing, since, for example, oil as a coolant is only present in certain sections of the housing. In certain other places, the oil may be absent, for example, in an air gap between the rotor and stator, preventing oil from escaping from the housing. This reduces the risk of fire on and in the housing.

[0018] According to a further embodiment, the housing can be characterized in that the fluid connection is closed and accessible via the two openings. For example, the fluid connection can only be accessible via the two openings. In addition to the two openings, further openings can be provided on the or on a further flange. For example, instead of an element connectable to a mechanical brake, a further flange can be provided on the other side and opposite the first flange at the other end of the stator core bars. Further openings can be provided there or in the first flange, which can also provide a fluid connection with the channels, for example a closed fluid connection. The fluid connection can be closed in such a way that it is only accessible via the above-mentioned openings.For example, the closed fluid connection allows the entire cooling liquid to be transported from the first opening through all channels and then to the second opening.

[0019] A closed fluid connection can further reduce the risk of fire because it ensures that all cooling fluid, such as oil, remains in the channels of the housing and does not get outside the channels into potentially dangerous, hotter parts of the housing. Additional connection points, such as additional openings, are not necessary because the flange can have all the openings for the fluid connection. This makes it relatively easy to position the openings relative to other openings in an adjacent element, for example on a flange of an adjacent gearbox. The cooling fluid can therefore be easily transported to and from the openings, for example via openings in a flange of an adjacent gearbox.

[0020] According to a further embodiment, the housing can be characterized in that channels can run through the stator core in the axial direction. The channels in the axial direction through the stator core can run straight through the stator core. All channels can run through the stator core in the axial direction. Thus, all channels can run parallel to each other in the axial direction through the stator core.

[0021] This allows the channels through the stator core to transport the coolant in an axial direction. This allows the housing to be cooled in an axial direction by allowing the channels to transport the coolant in an axial direction.

[0022] According to a further embodiment, the housing can be characterized in that a plurality of channels can be arranged through the stator core along a circumference of the stator core. All channels through the stator core can be arranged along a circumference of the stator core. The channels through the stator core can be arranged equidistantly from one another along a circumference of the stator core. For example, there can be a constant distance between individual, adjacent channels through the stator core. This distance can be the same between all channels through the stator core and can also be constant in the axial direction.

[0023] This allows the stator core and thus the stator and the stator's electrical wires to be cooled along the entire circumference of the stator core.

[0024] According to a further embodiment, the housing can be characterized in that a first stator core bar can have a channel for supplying the cooling liquid. A second, different stator core bar can have a different channel for discharging the cooling liquid. The supply and discharge of the cooling liquid can be defined relative to the stator core. If the flange comprises a plurality of first and, alternatively or additionally, a plurality of second openings, a plurality of stator core bars can each have a channel for supplying or discharging the cooling liquid. The channels of the second stator core bar can be larger than the channels of the first stator core bar.

[0025] By providing channels through the stator core bars, coolant can be supplied and removed. Additional pipes or structures for supplying or removing the coolant are not necessary. The stator core bars can therefore contribute both to the mechanical stability of the housing and to the supply and removal of the coolant. By increasing the inner diameter of the second stator core bar, which is used for removing the coolant, compared to the inner diameter of the first stator core bar, a more uniform flow rate of the coolant can be created along the fluid connection. For example, the second stator core bar can be arranged at a lower point than the first stator core bar. Due to gravity, the coolant in the channel in the second stator core bar can have a greater hydrostatic pressure than the coolant in the channel in the first generator core bar.This allows for better heat transfer from the electrical machine generated by the stator's electrical wires. Additional pipes for heat transfer are therefore unnecessary.

[0026] According to a further embodiment, the housing can be characterized in that the channels of the first stator core bar and the second stator core bar can extend in the axial direction. The channels of the first and second stator core bars can run parallel to each other. The channels of the first and second stator core bars can, for example, run parallel to the channels in the stator core.

[0027] Because the channels in the first and second stator core bars run in the axial direction, the supply and removal of the cooling liquid can be particularly efficient, since the supply and removal of the liquid can take place via the shortest route between the stator core and the flange. This makes it possible to do without unnecessary channels. According to a further embodiment, the housing can be characterized in that the channels can have a first annular channel and a second annular channel. The annular channels can be circular. The first and alternatively or additionally the second annular channel can be fastened to the end plate and alternatively or additionally arranged there. The first and second annular channels can have identical or different inner diameters. The first annular channel can be connected to the first opening via channels.The channels by which the annular channel and the first opening can be connected can be at least partially enclosed by the first stator core bar and alternatively or additionally run at least partially in the axial direction. The second annular channel can be connected to the second opening via channels. The channels by which the second annular channel can be connected to the second opening can be at least partially enclosed by the second stator core bar and alternatively or additionally run at least partially in the axial direction. The two annular channels can be connected to one another via channels through the stator core. For example, the annular channels along the circumference of the stator core are connected to one another via a plurality of channels in the stator core.

[0028] This allows the two annular channels to be supplied with coolant along the entire circumference of the stator core. In addition, the coolant can be drained from the channels in the stator core.

[0029] According to a further embodiment, the housing can be characterized in that the annular channels extend in a radial direction at a distance from an axis of the electric machine. The axis can correspond to the axis of the rotor of the electric machine. For example, the annular channels can extend at a constant distance in the radial direction from the axis of the electric machine. The annular channels can be spaced from one another in the axial direction. The annular channels can be spaced from the axis of the electric machine in the radial direction, approximately like the stator core.

[0030] Such annular channels allow the coolant to be supplied and removed over a particularly short distance. At the same time, the annular channels can be arranged outside the perimeter of the actual stator, which may be enclosed by the housing. This allows a rotor to rotate freely within the stator without colliding with the annular channels.

[0031] According to a further embodiment, the housing can be characterized in that an annular channel can be formed by connecting at least two parts. For example, some or all of the annular channels can be formed by connecting at least two parts. The two parts can be shaped, for example by deep drawing. The two parts can be welded together and alternatively or additionally screwed together. The annular channel can have an LI shape. For example, the annular channel can have a curved or angular LI shape. Both parts that can form the annular channel can each have an LI shape. The annular channels can have openings or holes via which the annular channels can be connected to one another via channels through the stator core. These openings can, for example, have different inner diameters in order to achieve the previously described effect of a uniform flow rate of the fluid connection.

[0032] This allows the annular channels to be manufactured in a particularly simple manner. The annular channels can be part of the end plates or at least arranged on the end plates, whereby one annular channel can be arranged on each end plate and, alternatively or additionally, can be part of the end plate.

[0033] According to a further embodiment, the housing can be characterized in that an annular channel is formed by a shaping process.

[0034] For example, a ring channel can be formed using 3D printing and alternatively or additionally by casting.

[0035] In a second aspect, the present invention relates to a stator of an electrical machine having a housing according to an embodiment of the first aspect of the present invention. The stator may have electrical leads. In a third aspect, the present invention relates to an electrical machine having a stator according to an embodiment of the second aspect of the present invention. The electrical machine may be a generator or, alternatively, an electric motor.

[0036] In a fourth aspect, the present invention relates to a wind turbine with an electric machine according to an embodiment of the third aspect of the present invention. In addition to the electric machine configured as a generator, the wind turbine can also have a transmission and a rotor, wherein the rotor can be mechanically connected to the electric machine via the transmission.

[0037] Short description of the characters

[0038] Figure 1 shows schematically a housing according to an embodiment of the invention.

[0039] Figure 2 shows in perspective a housing according to an embodiment of the invention.

[0040] Figure 3 shows schematically an electrical machine according to an embodiment of the invention.

[0041] Figure 4 shows schematically a housing according to an embodiment of the invention.

[0042] Figure 5 shows a sectional view of a housing according to an embodiment of the invention.

[0043] Figure 6 shows a perspective and sectional view of a housing according to an embodiment of the invention.

[0044] Figure 7 shows a sectional view and perspective of an annular channel of a housing of the previous figures.

[0045] Detailed Description of Embodiments Figure 1 shows a schematic representation of a housing 2 according to one embodiment of the invention. The housing 2 is a housing 2 for a stator 4 of an electrical machine 6, which is shown schematically in Figure 3. The electrical machine 6 has, in addition to the stator 4, a rotor 8. The housing 2 has an axial direction A, wherein the axial direction A and an axis a of the electrical machine 6 are arranged centrally to the elements of the electrical machine 6, the housing 2, the stator 4, and the rotor 8. A radial direction R is orthogonal to the axis a and the axial direction A and runs from the center of the rotor 8 outwards via the stator 4 to the housing 2.

[0046] Furthermore, the housing 2 shown schematically in Figure 1 comprises a stator core 10, stator core bars 12 and a flange 14. The housing 2 can be connected to a further element, for example a gearbox, via the flange 14. The stator core 10 is connected to the flange 14 via stator core bars 12, and the stator core bars 12 adjoin the flange 14. The stator core bars 12 are welded to the flange 14 and to the stator core 10. The housing 2 further comprises end plates 16, 18. The end plates 16, 18 delimit the stator core 10 in the axial direction A. The stator core bars 12 protrude in the axial direction A beyond the

[0047] End plate 16, 18 and the stator core 10. This is also shown in Figure 2, which shows a perspective view of the housing 2. Furthermore, electrical lines 22 of the stator 4 are shown in Figures 1 and 2. These are arranged on an inner side of the stator 4 and the stator core 10. Furthermore, an element 20 is shown, which connects to the stator core bars 12 and is welded to them.

[0048] Element 20 is connectable to a mechanical brake of the electric machine 6. The mechanical brake is not shown in detail in the figures. In one embodiment, element 20 is a further flange to which a generator cover, an end cover, or a brake caliper of the mechanical brake can be connected. In another embodiment, element 20 itself is such a generator cover or end cover.

[0049] Figure 4 schematically shows a housing 2 according to one embodiment. The housing 2 has channels 24, 26, 28, 30, 32, 34, 36. The housing 2 has the channels 24, 26, 28, 30, 32, 34, 36 for a cooling liquid. One channel 26 is part of an end plate 16 and one channel 24 is part of another end plate 18. The flange 14 has a first opening 38 and a second opening 40, wherein the second opening 40 is shown, for example, in Figure 5. As can be seen in Figures 4, 5, and 6, a plurality of channels 28 run through the stator core 10. The channels 28 through the stator core 10 run in the axial direction A. The channels 28 through the stator core 10 are arranged along a circumference of the stator core 10, which is clearly visible, for example, in Figure 6. Channels 28 in an upper part of the housing 2 have a smaller inner diameter than channels 28 in a lower part of the housing 2.This creates a uniform flow rate of the cooling fluid in the channels 28. The channels 24, 26, 28, 30, 32, 34, 36 provide a fluid connection from the first opening 38 to the second opening 40. The fluid connection is closed and accessible only through the two openings 38, 40.

[0050] A first stator core bar 12a, shown, for example, in Figures 5 and 6, has a channel 30 for supplying the cooling fluid. A second, different stator core bar 12b has a different channel 34 for discharging the cooling fluid. The channels 30 and 34 are of different lengths, and the channel 34 is longer than the channel 30 by approximately the length of the stator core 10 in the axial direction A.

[0051] As can be seen in Figure 5, the first opening 38 is arranged at a higher point on the housing 2 than the second opening 40. Furthermore, Figure 5 shows that the channels 30, 34 of the first stator core bar 12a and the second stator core bar 12b run in the axial direction A. Channels 32 and 36 are arranged orthogonally thereto and serve to connect the channels 30 and 34 to the channels 28 through the stator core 10. Furthermore, the housing 2 has a first annular channel 24 and a second annular channel 26, which are shown in Figure 6. The first annular channel 24 is connected to the first opening 38 via channels 30, 32. The second annular channel 26 is connected to the second opening 40 via channels 34, 36. The two annular channels 24, 26 are connected to one another via channels 28 through the stator core 10. The channels 32, 36 are neither completely enclosed by the stator core bars 12 nor by the ring channels 24, 26.The annular channels 24, 26 run in the radial direction R at a constant distance from the axis a of the electrical machine 6. They are spaced from each other in the axial direction A.

[0052] Figure 7 shows a perspective view of the annular channel 24. The annular channel 26 is constructed identically, but is not explicitly shown in the figures. The annular channel 24 is formed by connecting two parts 24a, 24b. These parts 24a, 24b each form a square U-shaped recess, which, when joined, forms the annular channel 24 with a rectangular cross-section. The parts 24a, 24b are welded together. Furthermore, the annular channel 24 has a further part 24c, which runs in the radial direction R at a distance from part 24a. In an embodiment not shown here, this part 24c is part of the end plate 18. Furthermore, holes 24d are provided in the annular channel 24. Via the holes 24d, an annular channel 24 is connected to the channels 28 through the stator core 10. In one embodiment, the holes 24d are smaller at an upper end and near the first opening 38 than at a lower end and near the second opening 40.This provides a uniform flow rate of the coolant in the fluid connection.

[0053] Reference symbol

[0054] 2 housings

[0055] 4 Stator

[0056] 6 Electric machine

[0057] 8 Rotor

[0058] 10 Stator core

[0059] 12, 12a, 12b Stator core rod

[0060] 14 Flange

[0061] 16, 18 End plate

[0062] 20 elements

[0063] 22 Electrical cable of the stator

[0064] 24, 26, 28, 30, 32, 34, 36 channel

[0065] 24a, 24b, 24c Parts of the ring canal

[0066] 24d holes of the ring channel

[0067] 38, 40 opening

[0068] A Axial direction

[0069] R Radial direction a Axis

Claims

Patent claims 1. Housing (2) for a stator (4) of an electrical machine (6), wherein the housing (2) has a stator core (10), stator core bars (12) and a flange (14), wherein the stator core (10) is connected to the flange (14) via the stator core bars (12) and wherein the stator core bars (12) adjoin the flange (14).

2. Housing (2) according to claim 1, characterized in that the housing (2) has an axial direction (A), that the housing (2) has end plates (16, 18) which delimit the stator core (10) in the axial direction (A), and that stator core bars (12) protrude in the axial direction (A) beyond at least one end plate (16; 18) and the stator core (10).

3. Housing (2) according to one of the preceding claims, characterized in that an element (20) adjoins stator core bars (12), wherein the element (20) is connectable to a mechanical brake of the electrical machine (6).

4. Housing (2) according to one of the preceding claims, characterized in that the housing (2) has channels (24, 26, 28, 30, 32, 34, 36) for a cooling liquid and the flange (14) has a first opening (38) and a second opening (40), that channels (28) run through the stator core (10), and that the channels (24, 26, 28, 30, 32, 34, 36) provide a fluid connection from the first opening (38) to the second opening (40).

5. Housing (2) according to claim 4, characterized in that the fluid connection is closed and is accessible via the two openings (38, 40).

6. Housing (2) according to one of claims 4 or 5, characterized in that channels (28) run in the axial direction (A) through the stator core (10).

7. Housing (2) according to claim 6, characterized in that a plurality of channels (28) are arranged through the stator core (10) along a circumference of the stator core (10).

8. Housing (2) according to one of claims 4 to 7, characterized in that a first stator core rod (12a) has a channel (30) for supplying the cooling liquid and a second, different stator core rod (12b) has another channel (34) for discharging the cooling liquid.

9. Housing (2) according to claim 8, characterized in that the channels (30, 34) of the first stator core bar (12a) and the second stator core bar (12b) extend in the axial direction (A).

10. Housing (2) according to one of claims 4 to 9, characterized in that the channels (24, 26, 28, 30, 32, 34, 36) have a first annular channel (24) and a second annular channel (26), that the first annular channel (24) is connected to the first opening (38) via channels (30, 32), that the second annular channel (26) is connected to the second opening (40) via channels (34, 36), and that the two annular channels (24, 26) are connected to one another via channels (28) through the stator core (10).

11. Housing (2) according to claim 10, characterized in that the annular channels (24, 26) extend in a radial direction (R) spaced from an axis (a) of the electrical machine (6) and are spaced from one another in the axial direction (A).

12. Housing (2) according to one of claims 10 or 11, characterized in that an annular channel (24; 26) is formed by connecting at least two parts (24a, 24b).

13. Housing (2) according to one of claims 10 to 12, characterized in that an annular channel (24; 26) is formed by a shaping process.

14. Stator (4) of an electrical machine (6) with a housing (2) according to one of the preceding claims.

15. Electrical machine (6) with a stator (4) according to the preceding claim.

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