DE102023211439B3 - Housing for a stator of an electrical machine - Google Patents

Abstract

A housing (2) for a stator (4) of an electrical machine (6) is described, wherein the housing (2) has a stator core (10), stator core bars (12) and a flange (14). The stator core (10) is connected to the flange (14) via the stator core bars (12) and the stator core bars (12) adjoin the flange (14). Furthermore, a stator (4) of an electrical machine (6) with such a housing (2) and an electrical machine (6) with such a stator (4) are described.

Description

technical field

The present invention relates to a housing for a stator of an electrical machine. The present invention also relates to a stator of an electrical machine with such a housing. The present invention also relates to an electrical machine with such a stator.

State of the art

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

In 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.

Out of DE 10 2020 104 263 A1 A stator for an electric motor is known, comprising a carrier component which extends along a virtual longitudinal axis defining an axial direction. The carrier component, which is thought to be centrally penetrated by the virtual longitudinal axis, has a carrier section with an external surface. The external surface faces in a radial direction orthogonal to the longitudinal axis. The carrier section has a metal frame overmolded by a thermoplastic carrier plastic, so that the metal frame is at least partially surrounded by a plastic jacket made of carrier plastic. The stator has a cover on at least one axial longitudinal end of the carrier section, which cover comprises a connection formation with cover plastic that is compatible with the carrier plastic or identical to it.

US 2006/0066 110 A1 discloses an electrical machine whose rotor has an inner and an outer core. A stator is double-sided.

Further state of the art is available from the publications US 2010/ 0 329 867 A1 , US 5 886 433 A , DE 10 2016 206 260 A1 and DE 10 2016 217 107 A1 known.

representation of the invention

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 cylindrically shaped. 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.

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 modularly connecting the housing and thus the electrical machine to other elements, such as a gearbox. The stator core can consist of layers and alternatively or additionally of packages of a material, for example steel. The layers or packages can be connected to one another, for example welded to one another. 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 several stator core bars, for example 6, 8, 10 or 12. The stator core bars can be arranged along a circumference of the stator core so that individual stator core bars are spaced apart from one another and run parallel to one another.

The stator core is connected to the flange via the stator core bars. The stator core can be connected to the flange via the stator core bars only, alternatively or additionally, primarily in a mechanical force-transmitting manner. For example, force transmission between the stator core and the flange can take place 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. 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.

By connecting the stator core to the flange via the stator core bars, a better power transmission of the housing can be provided. The stator core bars can thereby cover all or at least a large part of a Transfer force between the stator core and the flange. Any outer wall of the housing does not have to be designed to transfer force between the flange and the stator core. This means that such an outer wall can be made less thick and therefore lighter. This saves material and weight. However, the housing can be constructed more rigidly by connecting the flange and stator core using stator core rods, whereby the stability and rigidity of the stator core rods can ensure the stability and rigidity of the housing. Stator core rods, which may be necessary to connect the layers of the stator core, can therefore also be used to increase the stability and rigidity of the housing. Any outer wall can be connected to the stator core rods to further increase the rigidity and stability of the housing.

According to a further embodiment, the housing can be characterized in that the housing can have an axial direction. The stator core rods 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 limit the stator core in the axial direction. By means of the end plates, which are connected to the stator core rods, for example by a welded connection, a uniform clamping force can be exerted by the stator core rods on the layers of the stator core. The end plates can also be fastened to an outer wall of the housing, for example by screws or welded connections. Furthermore, stator core rods can protrude in the axial direction beyond at least one end plate and the stator core. For example, some or all stator core rods can protrude on one side and thus on one side in the axial direction beyond an end plate and the stator core. Alternatively, some or all stator core rods can protrude on both sides in the axial direction beyond both end plates and the stator core. For example, if the stator core bars protrude on both sides, they can protrude the same length or different lengths beyond the end plates and the stator core. The end plates can have recesses through which a stator core bar can protrude in each case.

The flange can be connected directly to the stator core via the stator core rods by the stator core rods projecting in the axial direction over the end plate and the stator core. The flange can be arranged axially offset from the stator core. Additional elements for connecting the flange and stator core are not necessary, for example. Connecting the stator core and flange via an outer wall, whereby the outer wall primarily contributes to the force transmission between the stator core and flange, is therefore not necessary. This means that the outer wall does not have to be designed to transfer the 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.

According to a further embodiment, the housing can be characterized in that an element can connect to stator core bars, wherein the element can be connected 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 the stator core bars can, for example, protrude through the element in such an embodiment. A brake disk 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 connected. For example, the flange can be arranged at one end of the stator core bars, and such an element can be arranged at the other end of the stator core bars.

This means that a mechanical brake can be connected to the housing in a particularly stable construction. This means that a mechanical brake can be provided for the electrical machine without having to make any further structural changes to the housing or the electrical machine.

The housing has channels for a cooling liquid. The cooling liquid can be water or oil, for example. Channels can be pipes, for example straight or curved pipes. The flange has 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 have similar or identical diameters, for example similar or identical inner diameters. Alternatively, parts of 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, run through the stator core. Holes can be provided in the layers of the stator core, for example by means of 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 be bonded together, for example, to ensure that the channels in the stator core are liquid-tight. The channels provide a fluid connection from the first opening to the second opening. For example, all channels in 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 exit the channels and the housing again through the second opening.

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 lines. This allows a higher torque density of the electrical machine to be achieved. This can increase the efficiency of the electrical machine in terms of the spatial expansion of the electrical machine. By cooling the stator core, cooling can take place spatially close to the stator itself and therefore to the electrical lines and therefore to the heat source. This can provide effective heat transfer and heat transport between the stator and the coolant, since the heat transport between the heat source and the coolant does not need to go through the entire stator core and possibly other elements. By cooling the stator, cooling the rotor can be optional, for example because cooling the stator can be more efficient than cooling the rotor. Furthermore, the channels running in the stator core make it possible to avoid the need for complex provision of 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 certain spatial section of the housing. This means that certain elements of the housing and the electrical machine can be protected from the cooling liquid and from direct contact with the cooling liquid. This means that open cooling with oil, for example, can be dispensed with. Such a housing can therefore be combined with additional air cooling, for example for the rotor of the electrical machine. This can also increase the safety of the housing, since oil as a cooling liquid is only present in certain sections of the housing. The oil may not be present in certain other places, for example in an air gap between the rotor and stator, which can prevent oil from escaping from the housing. This can reduce the risk of fire on and in the housing.

According to a further embodiment, the housing can be characterized in that the fluid connection is closed and is 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 that can be connected 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 entire cooling liquid can be transported from the first opening through all the channels and then to the second opening via the closed fluid connection.

A closed fluid connection can further reduce the risk of fire, as it can ensure that all cooling liquid, for example oil, remains in the channels of the housing and does not get outside the channels to potentially dangerous, hotter parts of the housing. Additional connection points, such as additional openings, are not necessary, as 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 liquid can therefore be easily transported to and from the openings, for example via openings in a flange of an adjacent gearbox.

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. All channels can therefore run through the stator core parallel to one another in the axial direction.

This allows the channels through the stator core to transport the cooling liquid in the axial direction. This allows the housing to expand in axially cooled by allowing the channels to transport the coolant in the axial direction.

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.

This allows the stator core and thus the stator and the stator's electrical lines to be cooled along the entire circumference of the stator core.

A first stator core rod has a channel for supplying the cooling liquid. A second, different stator core rod has a different channel for discharging the cooling liquid. Supplying and discharging the cooling liquid can be defined relative to the stator core. If the flange comprises several first and alternatively or additionally several second openings, several stator core rods can each have a channel for supplying or discharging the cooling liquid. The channels of the second stator core rod can be larger than the channels of the first stator core rod.

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

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 run 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.

Because the channels in the first and second stator core bars run in an axial direction, the cooling liquid can be supplied and discharged particularly efficiently, as the liquid can be supplied and discharged via the shortest route between the stator core and the flange. This means that unnecessary channels can be dispensed with.

The channels have a first ring channel and a second ring channel. The ring channels can be circular. The first and alternatively or additionally the second ring channel can be attached to the end plate and alternatively or additionally arranged there. The first and second ring channels can have identical or different inner diameters. The first ring channel is connected to the first opening via channels. The channels to which the ring channel and the first opening can be connected can be at least partially enclosed by the first stator core rod and alternatively or additionally run at least partially in the axial direction. The second ring channel is connected to the second opening via channels. The channels to which the second ring channel can be connected to the second opening can be at least partially enclosed by the second stator core rod and alternatively or additionally run at least partially in the axial direction. The two ring channels are connected to one another via channels through the stator core. For example, the ring channels along the circumference of the stator core are connected to one another via several channels of the stator core.

This means that the channels through the stator core along the entire circumference of the stator core can be supplied with coolant via the two ring channels. In addition, the coolant can be drained from the channels in the stator core.

According to a further embodiment, the housing can be characterized in that the ring channels run in a radial direction at a distance from an axis of the electrical machine. The axis can correspond to the axis of the rotor of the electrical machine. For example The ring channels can run at a constant distance in the radial direction from the axis of the electrical machine. The ring channels can be spaced apart from one another in the axial direction. The ring channels can be spaced apart from the axis of the electrical machine in the radial direction, approximately like the stator core.

With such ring channels, the cooling liquid can be supplied and discharged over a particularly short distance. At the same time, the ring channels can be arranged outside the circumference of the actual stator, which can be enclosed by the housing. This allows a rotor in the stator to rotate unhindered without colliding with the ring channels.

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 a U-shape. For example, the annular channel can have a curved or angular U-shape. Both parts that can form the annular channel can each have a U-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 the uniform flow rate of the fluid connection.

The ring channels can thus be produced in a particularly simple manner. The ring channels can be part of the end plates or at least arranged on the end plates, whereby one ring channel can be arranged on an end plate and alternatively or additionally can be part of the end plate.

According to a further embodiment, the housing can be characterized in that an annular channel is formed by a shaping process. For example, an annular channel can be formed by 3D printing and alternatively or additionally by casting.

In a second aspect, the present invention relates to a stator of an electrical machine with a housing according to an embodiment of the first aspect of the present invention. The stator can have electrical lines.

In a third aspect, the present invention relates to an electrical machine with a stator according to an embodiment of the second aspect of the present invention. The electrical machine can be a generator, alternatively an electric motor.

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 designed as a generator, the wind turbine can also have a gear and a rotor, wherein the rotor can be mechanically connected to the electric machine via the gear.

Short description of the characters

• 1 shows schematically a housing according to an embodiment of the invention.
• 2 shows in perspective a housing according to an embodiment of the invention.
• 3 shows schematically an electrical machine according to an embodiment of the invention.
• 4 shows schematically a housing according to an embodiment of the invention.
• 5 shows a sectional view of a housing according to an embodiment of the invention.
• 6 shows in perspective and in a sectional view a housing according to an embodiment of the invention.
• 7 shows in a sectional view and in perspective an annular channel of a housing of the previous figures.

Detailed description of embodiments

1 shows a schematic representation of a housing 2 according to an 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 3 is shown. The electric machine 6 has a rotor 8 in addition to the stator 4. The housing 2 has an axial direction A, wherein the axial direction A and an axis a of the electric machine 6 are arranged centrally to the elements of the electric 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.

Furthermore, the schematically shown 1 shown housing 2 a stator core 10, stator core rods 12 and a flange 14. The housing 2 can be connected to another element, for example a gear, via the flange 14. The stator core 10 is connected to the flange 14 via stator core rods 12 and the stator core rods 12 adjoin the flange 14. The stator core rods 12 are welded to the flange 14 and to the stator core 10. The housing 2 also has end plates 16, 18. The end plates 16, 18 limit the stator core 10 in the axial direction A. The stator core rods 12 protrude in the axial direction A beyond the end plate 16, 18 and the stator core 10. This is also in 2 , which shows a perspective view of the housing 2. Furthermore, in 1 and 2 electrical lines 22 of the stator 4 are shown. 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 stator core bars 12 and is welded to them. The element 20 can be connected to a mechanical brake of the electrical machine 6. The mechanical brake is not shown in detail in the figures. In one embodiment, the 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 a further embodiment, the element 20 itself is such a generator cover or end cover.

4 shows schematically a housing 2 according to an 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. A channel 26 is part of an end plate 16 and a channel 24 is part of another end plate 18. The flange 14 has a first opening 38 and a second opening 40, the second opening 40 being, for example, in 5 As shown in the 4 , 5 , 6 As can be seen, several 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 for example in 6 is clearly visible. 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 liquid 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 only accessible via the two openings 38, 40.

A first stator core bar 12a, for example shown in 5 and 6 , has a channel 30 for supplying the cooling liquid. A second, different stator core rod 12b has another channel 34 for discharging the cooling liquid. 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.

As in 5 As can be seen, the first opening 38 is arranged at a higher location on the housing 2 than the second opening 40. Furthermore, in 5 It can be seen that the channels 30, 34 of the first stator core rod 12a and the second stator core rod 12b run in the axial direction A. Channels 32 and 36 are arranged orthogonally to this and serve to connect the channels 30 and 34 with 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 in 6 are shown. The first ring channel 24 is connected to the first opening 38 via channels 30, 32. The second ring channel 26 is connected to the second opening 40 via channels 34, 36. The two ring 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 ring channels 24, 26 run in the radial direction R at a constant distance from the axis a of the electric machine 6. They are spaced from each other in the axial direction A.

In 7 the ring channel 24 is shown in a perspective view. The ring channel 26 is constructed identically, but is not explicitly shown in the figures. The ring channel 24 is formed by connecting two parts 24a, 24b. These parts 24a, 24b each form a square U-shaped recess, which when joined together forms the ring channel 24 with a rectangular cross-section. The parts 24a, 24b are welded together. The ring channel 24 also has a further part 24c, which runs in the radial direction R at a distance from the 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 ring channel 24. A ring channel 24 is connected to the channels 28 through the stator core 10 via the holes 24d. 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 cooling liquid in the fluid connection.

reference sign

2

Housing

4

stator

6

Electric Machine

8

rotor

10

stator core

12, 12a, 12b

stator core rod

14

flange

16, 18

end plate

20

element

22

Electrical line of the stator

24, 26, 28, 30, 32, 34, 36

channel

24a, 24b, 24c

parts of the ring canal

24d

holes of the ring channel

38, 40

opening

A

axial direction

R

radial direction

a

axis

Claims (12)

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), wherein 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), wherein channels (28) run through the stator core (10), wherein the channels (24, 26, 28, 30, 32, 34, 36) provide a fluid connection from the first opening (38) to the second opening (40), wherein a first stator core bar (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, wherein the channels (24, 26, 28, 30, 32, 34, 36) have a first annular channel (24) and a second annular channel (26), wherein the first annular channel (24) is connected to the first opening (38) via channels (30, 32), and wherein the second annular channel (26) is connected to the second opening (40) via channels (34, 36), and wherein the two annular channels (24, 26) are connected to one another via channels (28) through the stator core (10). Housing (2) after 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). Housing (2) according to one of the preceding claims, characterized in that an element (20) adjoins the stator core bars (12), wherein the element (20) is connectable to a mechanical brake of the electrical machine (6). Housing (2) according to one of the preceding claims, characterized in that the fluid connection is closed and is accessible via the two openings (38, 40). Housing (2) according to one of the preceding claims, characterized in that channels (28) run in the axial direction (A) through the stator core (10). Housing (2) after claim 5 , characterized in that a plurality of channels (28) are arranged through the stator core (10) along a circumference of the stator core (10). Housing (2) according to one of the preceding claims, characterized in that the channels (30, 34) of the first stator core rod (12a) and the second stator core rod (12b) extend in the axial direction (A). Housing (2) according to one of the preceding claims, characterized in that the annular channels (24, 26) extend in a radial direction (R) at a distance from an axis (a) of the electrical machine (6) and are spaced from one another in the axial direction (A). Housing (2) according to one of the preceding claims, characterized in that an annular channel (24; 26) is formed by connecting at least two parts (24a, 24b). Housing (2) according to one of the preceding claims, characterized in that an annular channel (24; 26) is formed by a shaping process. Stator (4) of an electrical machine (6) with a housing (2) according to one of the preceding claims. Electric machine (6) with a stator (4) according to the preceding claim.

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