Stator tooth with ring-segment-shaped stator core, axial flux machine and method for manufacturing the stator tooth

Abstract

The invention relates to a stator tooth (SZ) for a stator of an axial flux machine of an at least partially electrically powered motor vehicle, comprising a stator core (SK) shaped like an annular segment, which is formed from a plurality of stacked laminations (BL), wherein the laminations (BL) have a longitudinal direction (LR), and the laminations (BL) are stacked such that the longitudinal direction (LR) of the laminations (BL) runs in the radial direction of the annular segment.

Description

[0001] The invention relates to a stator tooth for an axial flux machine of an at least partially electrically powered motor vehicle, comprising a stator core, wherein the stator core forms a circular ring segment. The stator core is formed from a plurality of laminations, wherein a longitudinal direction of the laminations runs in the radial direction of the circular ring segment. The invention further relates to an axial flux machine with the stator tooth according to the invention. The invention further relates to a method for producing the stator tooth.

[0002] Stator teeth for a stator of an axial flux machine are generally known. The known stator teeth typically comprise a stator core, with the stator core having a trapezoidal configuration in the longitudinal direction of the stator. The trapezoidal configuration of the stator core is formed by a plurality of laminations of different sizes that are stacked one upon another in a radial direction of the stator. Such a stator core is shown, for example, in DE 10 2022 112 496 A1. A disadvantage of this type of stator core is, on the one hand, the large number of different lamination sizes, as this requires a large number of punching tools, which can increase manufacturing costs. On the other hand, the stepped configuration of the trapezoidal stator core reduces the fill level of the lamination material, which can negatively impact the performance of the axial flux machine.

[0003] It is an object of the invention to provide a stator tooth for an axial flux machine of an at least partially electrically driven motor vehicle, which can be produced inexpensively and with which the performance of the axial flux machine can be increased.

[0004] This problem is solved by the subject matter of the independent patent claims. Preferred developments of the invention are the subject matter of the dependent patent claims, the following description, and the drawings. Each feature can represent an aspect of the invention, both individually and in combination, unless explicitly stated otherwise in the description.

[0005] In a first aspect, the invention relates to a stator tooth for a stator of an axial flux machine of an at least partially electrically driven motor vehicle, comprising a stator core in the shape of a circular ring segment, which is formed from a plurality of laminated sheets stacked on top of one another, wherein the laminated sheets have a longitudinal direction, and the laminated sheets are stacked on top of one another in such a way that the longitudinal direction of the laminated sheets runs in the radial direction of the circular ring segment.

[0006] In other words, according to the first aspect of the invention, a stator tooth is provided for a stator of an axial flux machine of an at least partially electrically powered motor vehicle. The axial flux machine is preferably part of a traction drive for the motor vehicle, so that the motor vehicle can be set in motion via the axial flux machine. The stator tooth has a stator core which has the shape of a circular ring segment. The shape of the circular ring segment preferably relates to a plan view of the circular ring segment in its longitudinal direction. If the stator core is arranged in a stator, the shape of the circular ring segment of the stator core preferably relates to a longitudinal direction of the stator in the axial flux machine. The stator core is formed by a plurality of laminations which are stacked on top of one another.The laminations have a longitudinal direction that is preferably formed and / or aligned parallel to a plane of the laminations. The longitudinal direction of the laminations is aligned in the radial direction of the circular ring segment. Thus, the laminations have a completely different structure compared to the known prior art. The circular ring segment-shaped design of the stator core allows for an increased fill ratio of the lamination content compared to the trapezoidal design of the stator core, which can have a beneficial effect on the performance of the axial flux machine. Furthermore, uniform laminations can be used for the stator core, which can reduce the manufacturing costs of the stator core and thus of the axial flux machine.

[0007] The sheets are preferably made of electrical steel.

[0008] In principle, the sheets can be designed in such a way that, when stacked on top of one another, they have a circular ring segment-shaped geometry or configuration.

[0009] An advantageous development of the invention lies in the fact that the laminations comprise a first group of laminations which, in cross-section, form the geometry of an isosceles trapezoid. In other words, a first group of laminations is provided, and the laminations of the first group are trapezoidal in shape. The trapezoidal shape is an isosceles trapezoid. The isosceles trapezoid has a short base side and a long base side running parallel to the short base side. The short base side and the long base side are connected to one another via the legs. The longitudinal axis or longitudinal direction of a lamination extends between the short base side and the long base side. The short base side is directed radially inwards with respect to the circular ring-segment-shaped contour of the stator core.The trapezoidal contour of the first group of laminations allows the circular ring segment-shaped stator core to be formed in a simple and cost-effective manner.

[0010] In this context, an advantageous development of the invention is that the stator core is formed exclusively from a first group of laminations. In other words, the stator core is formed exclusively from laminations, each of which has the contour of an isosceles trapezoid in cross-section. Thus, a stator core shaped like a circular ring segment can be provided in a simple and cost-effective manner.

[0011] It is conceivable that the sheets of the first group all have a trapezoidal configuration in cross-section, although the trapezoidal shape of the different sheets can vary. In other words, it can be provided that a sheet of the first group has a trapezoidal shape in cross-section that differs from the trapezoidal shape of another sheet of the first group. However, it is provided that the length of the sheets between the first base side and the second base side is identical in each case.

[0012] Alternatively, a preferred embodiment of the invention is that the laminations of the first group are of identical cross-section. In other words, each lamination of the first group is identical. In this way, the manufacturing costs of the stator core can be reduced. This is even more true if the stator core is made exclusively from, or comprises, laminations of the first group.

[0013] It is conceivable, and not excluded, that the sheets comprise the first group of sheets and at least one sheet from a second group that has a rectangular geometry in cross-section. In other words, it can be provided that, in addition to sheets with a trapezoidal cross-section in the first group, at least one sheet from a second group that has a rectangular cross-section is also provided.

[0014] In an advantageous development of the invention, it is provided that the laminations are connected to one another. The connection can be a material connection and / or a form-fitting connection. The material connection is preferably realized using a baking varnish. This is applied to the laminations, and the laminations are baked together by the introduction of heat. The form-fitting connection is preferably a stamped connection. The laminations are connected to one another by a stamping process. However, it is also conceivable that the laminations arranged to form a circular ring segment are at least partially covered with a plastic material. The plastic material is, on the one hand, a material connection, and if formed circumferentially around the stator core, also a form-fitting connection. A stator winding is preferably wound onto the plastic material.This provides different options for connecting the sheets to form a circular ring segment.

[0015] According to an advantageous embodiment of the invention, the laminations have a recess extending in the tangential direction of the stator core on an outer side and / or inner side directed in the radial direction of the annular segment-shaped stator core. The recess can preferably be a notch. The laminations can preferably be stacked on top of one another with particularly precise fit via the notch, particularly when a guide pin of a stator core holder engages in the notch to position the laminations on top of one another. This can increase the accuracy of fit of the laminations to form the stator core.

[0016] In a second aspect, the invention relates to an axial flux machine with the stator tooth according to the invention.

[0017] The axial flux machine is preferably a component of a traction drive for an at least partially, preferably completely, electrically powered motor vehicle.

[0018] In a third aspect, the invention relates to a method for producing a stator tooth for a stator of an axial flux machine, in particular for producing the stator tooth according to the invention, comprising the steps: - Providing a sheet metal blank; - punching out a plurality of sheets from the sheet metal blank; - Stacking the sheets to form a circular ring segment, wherein a longitudinal direction of the sheets is formed in the radial direction of the circular ring segment.

[0019] In other words, according to the third aspect of the invention, a method for producing a stator tooth is provided, wherein the stator tooth is preferably arranged in a stator for an axial flux machine of an at least partially electrically driven motor vehicle.

[0020] In a first step, a sheet metal blank is prepared. The sheet metal blank is preferably electrical steel.

[0021] In a second step, a number of sheets are punched out of the sheet metal blank.

[0022] In a third step, the laminations are arranged to form a circular ring segment, with a longitudinal direction of the laminations extending radially along the circular ring segment. This allows for the provision of a stator core for a stator tooth that has a higher fill ratio of the electrical laminations and is also cost-effective to manufacture, since the stator core can be manufactured with a reduced number of different laminations.

[0023] An advantageous development of the invention is that before the sheets are punched out of the sheet metal blank, the sheet metal blank is rolled so that its cross-section forms an isosceles trapezoid. In this way, sheets of the first group can be manufactured simply and inexpensively. Using these sheets, the stator core can be manufactured simply and inexpensively, forming a circular ring segment.

[0024] Finally, an advantageous embodiment of the invention is that, when punching the sheets from the sheet metal blank, the sheet metal blank is placed on a beveled punching surface, so that a plane or longitudinal direction of the sheet metal blank is aligned in a direction perpendicular to a punching direction for punching the sheet metal. In this way, a sheet of the first group can preferably be easily manufactured to fit the stator core precisely, so that the majority of the stacked sheets form a circular ring segment.

[0025] It should be noted that all features described above and below with respect to one aspect of the present invention equally apply to any other aspect of the present invention. In particular, all features of the stator tooth can also be features of the axial flux machine and the method for manufacturing the stator tooth. This also applies vice versa.

[0026] Further features and advantages of the present invention emerge from the dependent claims and the following exemplary embodiments. The exemplary embodiments are not limiting, but rather are to be understood as examples. They are intended to enable the skilled person to implement the invention. The applicant reserves the right to make individual and / or several of the features disclosed in the exemplary embodiments the subject of patent claims or to incorporate such features into existing patent claims. The exemplary embodiments are explained in more detail with reference to drawings.

[0027] In these show: Fig. 1 a three-dimensional view of a stator tooth according to the prior art; Fig. 2 is a plan view of a stator core of the stator tooth according to the prior art; Fig. 3 is a plan view of the stator core according to the invention; Fig. 4 a method for manufacturing the stator core.

[0028] In Fig. Figure 1 shows a three-dimensional view of a stator tooth SZ according to the prior art. The stator tooth SZ has a stator core SK, which has a trapezoidal configuration. A plastic encapsulation KV is formed on an outer surface AM of the stator core SK, on ​​which a stator winding SW is wound.

[0029] The stator core SK comprises a multitude of differently sized laminations BL, which are stacked on top of one another in such a way that the stator core SK has a trapezoidal shape when viewed from above. A disadvantage of this type of stator core SK is, on the one hand, the large number of different lamination sizes, as this requires a large number of punching tools, which can increase the manufacturing costs of the stator tooth SZ. On the other hand, the stepped design of the trapezoidal stator core SK reduces the fill level of the lamination material, which can negatively impact the performance of the axial flux machine.

[0030] To ensure the filling level of the sheet material, the known state of the art, as in Fig. As shown in Figure 2, the stator core SK comprises stepped laminated cores BP, each laminated core BP comprising a plurality of laminations BL. This design has the disadvantage that the stator core is larger and therefore heavier. Another disadvantage is the increased number of required punching tools.

[0031] In Fig. Figure 3 shows a plan view of the stator core SK for a stator tooth SZ according to the invention. The stator core SK has the shape of a circular ring segment. The shape of the circular ring segment preferably refers to a plan view of the circular ring segment in its longitudinal direction. When the stator core SK is arranged in a stator, the shape of the circular ring segment of the stator core preferably refers to a longitudinal direction of the stator in the axial flux machine. The stator core SK is formed by a plurality of laminations BL that are stacked on top of one another. The laminations BL have a longitudinal direction that is preferably formed and / or aligned parallel to a plane of the laminations BL. The longitudinal direction of the laminations BL is aligned in the radial direction of the circular ring segment. In this way, the laminations BL have a completely different structure compared to the known prior art.The circular ring-segment design of the SK stator core allows for a higher fill ratio of the lamination content compared to the trapezoidal design of the SK stator core, which can have a beneficial effect on the performance of the axial flux machine. Furthermore, uniform BL laminations can be used for the SK stator core, which can reduce the manufacturing costs of the SK stator core and thus of the axial flux machine.

[0032] The laminations BL have a first group of laminations BL which, in cross-section, form the geometry of an isosceles trapezoid. In other words, a first group of laminations BL is provided, and the laminations BL of the first group are trapezoidal in shape. The trapezoidal shape is an isosceles trapezoid. The isosceles trapezoid has a short base side KG and a long base side LG running parallel to the short base side. The short base side KG and the long base side LG are connected to one another via the legs. The longitudinal axis or longitudinal direction LR of a lamination BL extends from the short base side KG to the long base side LG. The short base side KG is directed radially inwards with respect to the circular ring-segment-shaped contour of the stator core SK.The circular ring segment-shaped stator core SK can be formed in a simple and cost-effective manner using the trapezoidal contour of the first group of sheets BL.

[0033] In Fig. 4 shows a method for producing a stator tooth SZ.

[0034] In a first step 100, a sheet metal blank BR is provided. The sheet metal blank BR is preferably an electrical steel.

[0035] In a second step 110, the sheet metal blank BR is rolled between two conically shaped and counter-rotating rollers RO in such a way that the sheet metal blank BR has a trapezoidal configuration in a cross-section.

[0036] In a third step 120, a sheet BL is punched from the sheet metal blank BR, which has a trapezoidal cross-section.

[0037] In a fourth step 130, the punched laminations BL from the sheet metal blank BR are arranged to form a circular ring segment, thus forming the stator core SK. The longitudinal direction LR of the laminations BL runs in the radial direction of the circular ring segment. Thus, the stator core SK is provided for a stator tooth SZ, which can have a higher fill ratio of the electrical laminations and is also inexpensive to manufacture, since the stator core SK can be manufactured with a reduced number of different laminations BL. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] DE 10 2022 112 496 A1

[0002]

Claims

[1] Stator tooth (SZ) for a stator of an axial flux machine of an at least partially electrically driven motor vehicle, comprising a stator core (SK) in the shape of a circular ring segment, which is formed from a plurality of laminations (BL) stacked on top of one another, wherein the laminations (BL) have a longitudinal direction (LR), and the laminations (BL) are stacked on top of one another in such a way that the longitudinal direction (LR) of the laminations (BL) runs in the radial direction of the circular ring segment. [2] Stator tooth according to claim 1, characterized by that the sheets (BL) have a first group of sheets (BL) which form a geometry of an isosceles trapezoid in a cross-section. [3] Stator tooth according to claim 2, characterized by that the stator core (SK) is formed exclusively from a first group of laminations (BL). [4] Stator tooth according to one of claims 2 to 3, characterized bythat the sheets (BL) of the first group have the same cross-section. [5] Stator tooth according to one of claims 2 to 4, characterized by that the sheets (BL) comprise the first group of sheets (BL), and at least one sheet (BL) of a second group which has a rectangular geometry in a cross-section. [6] Stator tooth according to one of the preceding claims, characterized by that the sheets (BL) are connected to each other. [7] Stator tooth according to one of the preceding claims, characterized by that the laminations (BL) have a recess running in the tangential direction of the stator core (SK) on an outer side and / or inner side directed in the radial direction of the stator core (SK). [8] Axial flux machine with a stator tooth (SZ) according to one of the preceding claims. [9] Method for producing a stator tooth (SZ) for a stator of an axial flux machine, comprising the steps: - Providing a sheet metal blank (BR); - punching out a plurality of sheets (BL) from the sheet metal blank (BR); - Stacking the laminations (BL) to form a circular ring segment to form a stator core (SK), wherein a longitudinal direction of the laminations (BL) is formed in the radial direction of the circular ring segment. [10] Method according to claim 9, characterized by that before the sheets (BL) are punched out of the sheet blank (BR), the sheet blank (BR) is rolled so that it forms an isosceles trapezoid in cross-section. [11] Method according to claim 9 or 10, characterized by that when punching out the sheets (BL) from the sheet metal blank (BR), the sheet metal blank (BR) is placed on a bevelled punching surface so that a plane of the sheet metal blank (BR) is aligned in a direction perpendicular to a punching direction for punching out the sheet metal (BL).

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