Stator lamination, laminated stator core and stator, each for an electric machine, and electric machine and motor vehicle having such an electric machine

Abstract

The invention relates to a stator lamination (1), a laminated stator core (2) and a stator (3) of an electric machine, wherein the stator lamination (1) has a heat sink structure (18), the heat sinks (19, 20) of which each protrude radially outward from an annular yoke disk (10) of the stator lamination (1) and are mutually spaced along a stator lamination circumferential direction (u) by a heat sink spacing (24, 25). The heat sinks (19, 20) each have a long, first heat sink flank (26) and a short, second heat sink flank (27), wherein the first heat sink flanks (26) are each rooted on the inner root circle outer circumferential surface (14), and the second heat sink flanks (27) are each rooted on the outer root circle outer circumferential surface (16). One of two heat sink spacings (24, 25) which are arranged in direct succession along the stator lamination circumferential direction (u) is delimited by two mutually facing first heat sink flanks (26), and the corresponding other of the heat sink spacings (24, 25) is delimited by two mutually facing second heat sink flanks (27).

Description

[0001] Stator lamination, stator lamination stack and stator, each for an electric machine, as well as electric machine and motor vehicle with such an electric machine

[0002] The present invention relates to a stator lamination for a stator lamination stack of an electric machine and a stator lamination stack for a stator of an electric machine, wherein the stator lamination stack comprises a plurality of such stator laminations. The invention further relates to a stator comprising such a stator lamination stack and to an electric machine comprising such a stator. The invention also relates to a motor vehicle comprising such an electric machine.

[0003] To ensure the most efficient operation possible, electric machines must be cooled. Particularly in automotive engineering, it has proven advantageous to use oil as a coolant for electric drive or traction motors. This oil is also used elsewhere in the vehicle, for example, as a lubricant in the vehicle's transmission. For direct cooling of the electric machine's stator, a stator lamination stack is mounted in a stator housing in such a way that a radial gap is formed between an inner surface of the stator housing and an outer surface of the stator lamination stack. The coolant flows through this gap. To achieve particularly efficient heat transfer between the stator and the coolant or oil, it is known in the art to provide an outer surface of the stator with a structure that maximizes the usable surface area of ​​the stator for heat transfer.

[0004] Supplementary sheet | For example, DE 10 2007 048 683 A1 and DE 10 2012 211 501 A1 each propose attaching a cooling element structure to an outer surface of a stator for an electric machine in order to cool the stator more efficiently. Furthermore, DE 10 2020 132 094 A1 proposes a stator with an unspecified outer surface, wherein the stator has axial cooling channels intersected by webs. However, these solutions are highly complex and lead to a particularly elaborate manufacturing process for the stator lamination stack as well as a particularly complex assembly process for the corresponding electric machine.

[0005] The object of the present invention is to provide a solution for particularly efficient direct stator cooling.

[0006] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, across categories and embodiments as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

[0007] According to the invention, a stator lamination for a stator lamination stack of an electric machine is proposed. Regardless of the embodiment, the stator lamination has four quarter-circle-shaped stator lamination quadrants Q1, Q2, Q3, Q4, which are numbered in ascending order counterclockwise. As shown in Fig. 1, the stator lamination quadrants Q1 (top right), Q2 (top left), Q3 (bottom left), and Q4 (bottom right) are derived from the x, y, z coordinate system according to the general convention customary in engineering / geometry. The x-axis and a longitudinal center axis of the stator lamination coincide, as do the y-axis and a transverse axis of the stator lamination. Furthermore, the z-axis and a vertical axis of the stator lamination coincide. An origin of the coordinate system x, y, z is defined herein such that it coincides with a stator lamination center M of the stator lamination, which is located exactly at half the thickness of the stator lamination.The stator lamination has a yoke ring disk with alternating stator teeth and stator slots on its inner circumference. During stator manufacturing, the stator teeth are wound with wire, so that the wire windings are positioned in the stator slots. Furthermore, the yoke ring disk has an inner and an outer root circle surface. These two root circle surfaces differ in their diameter or radius. The radius of the inner root circle surface originating from the center M of the stator lamination is smaller than the radius of the outer root circle surface originating from the same center M.

[0008] The stator lamination further features a heat sink structure comprising numerous heat sinks. Each heat sink is designed, for example, as a cuboid-shaped protrusion. The heat sinks project radially outwards to a tip circumferential surface of the yoke ring disk. The tip circumferential surface has a radius originating from the stator lamination center M that is larger than the radius of the outer base circumferential surface. The heat sinks are spaced apart along one circumferential direction of the stator lamination by a heat sink spacing. Each heat sink also has a long, first heat sink flank and a short, second heat sink flank, with the first heat sink flanks resting on the inner base circumferential surface and the second heat sink flanks resting on the outer base circumferential surface.Considering three heat sinks arranged consecutively along the stator lamination's circumference, it becomes apparent that a gap exists between one outer and middle heat sink, and between the middle and outer heat sinks. These gaps differ in their design. Radially outward, or from the tip's circumferential surface, one of the gaps has a greater radial depth than the other. The deeper gap is bounded by two opposing first heat sink flanks. This gap is referred to here as the "first heat sink gap." Conversely, the shallower gap is bounded by two opposing second heat sink flanks. This gap is referred to here as the "second heat sink gap."Along the circumferential direction u of the stator lamination, the first and second heat sink spacings are of equal length, each extending over an equal arc length of the yoke ring disk. Due to the heat sink structure with the first and second heat sinks, the stator lamination advantageously has a particularly large outer circumferential area, which promotes especially efficient heat dissipation from the stator lamination material.

[0009] Furthermore, according to the invention, a stator lamination stack for an electric machine stator is proposed, comprising a plurality of stator laminations arranged along a longitudinal center axis of the stack. Each stator lamination thus forms a component of the stator lamination stack. For example, the stator laminations of the stator lamination stack are axially clamped together. Since the stator laminations each have a particularly large outer circumferential surface area due to the heat sink structure, the stator lamination stack consequently has an advantageously large outer surface area. This promotes particularly efficient heat dissipation from the material of the stator lamination stack.

[0010] The invention further proposes a stator for the electric machine, comprising a stator housing whose laminated core chamber is bounded by an inner surface of the stator housing. The stator lamination stack, containing the stator laminations, is mounted in a rotationally fixed manner within the laminated core chamber, with a longitudinal center axis of the stator lamination stack and a longitudinal center axis of the laminated core chamber coinciding. A radial gap is formed between the inner surface and the tip circumferential surface, into which the heat sinks project radially. The radial gap is effectively covered radially by the inner surface of the laminated core chamber. For cooling the stator, or for direct cooling (immersion cooling) of the stator lamination stack, a coolant can be introduced into the radial gap, flowing directly along the outer surface of the stator lamination stack and thus directly around the heat sinks. This provides a particularly efficient, direct, or immersion cooling method.This enables direct (liquid) cooling of the stator or stator lamination stack. The aforementioned structuring of the outer shell surface improves heat transfer through turbulent mixing of the coolant flow. The fluid flow is deflected three-dimensionally, flowing tangentially along the longitudinal center axis of the lamination stack to the right and left of the heat sinks or heat sink flanks, and also radially upwards and downwards along the longitudinal center axis of the lamination stack due to the varying depths of the heat sinks. A further aspect of the invention is the electric machine, which includes the stator or a further development thereof. The electric machine is, in particular, a traction machine for a motor vehicle. Such a vehicle constitutes another aspect of the invention. The motor vehicle includes the electric machine, specifically as a traction machine.The motor vehicle can therefore be a purely electric or hybrid electric vehicle.

[0011] To supply and discharge the coolant or oil, the stator housing, in a possible further development, has a coolant inlet opening and a coolant outlet opening, both of which open into the lamination stack chamber and consequently into the radial gap. These coolant openings allow the stator housing to be fluidically integrated into a coolant circuit, particularly an oil circuit. This oil circuit is specifically a motor vehicle oil circuit, into which other vehicle components, such as the transmission, etc., are fluidically integrated and supplied with oil. It can be designed that the stator housing, i.e., its lamination stack chamber, is fluidically sealed except for the coolant openings.

[0012] In another possible embodiment of the stator lamination, it is designed as a single piece. In other words, the yoke ring and the heat sink structure—that is, the heat sinks—are formed by a single, monolithic piece of material. The yoke ring and the heat sink structure are manufactured together in a single production step, for example, by laser cutting from a common workpiece sheet. The stator lamination is particularly easy, quick, and cost-effective to manufacture when produced as a stamped part. In a single stamping process, especially a single stamping stroke, the yoke ring and the heat sink structure are produced simultaneously.Further components not connected to the yoke ring disk, as well as other / additional manufacturing processes for producing the stator lamination, are deliberately omitted.

[0013] In a possible further development of the stator lamination, it features a mounting lug unit comprising at least one mounting lug connected to the yoke ring disk at the tip circumferential surface. This connection is achieved by linking a radially inner mounting lug base to a respective radially outer heat sink end of two or more heat sinks. Each of the two or more heat sinks thus forms a connecting element by means of which the mounting lug and the yoke ring disk are metallurgically bonded. Due to the geometry of the stator laminations, the radial gap formed between the stator lamination stack and the inner surface of the stator housing continues beneath the mounting lugs, or between the mounting lug bases and the outer circumferential surface of the root circle.In the area of ​​the mounting tabs, the radial gap is effectively covered by the corresponding mounting tab base, whereas the radial gap away from the mounting tabs is covered by the inner surface of the laminated core chamber. Since the heat sinks are spaced apart by the heat sink spacing, a grid-like structure forms between the mounting tab and the yoke ring disk. The radial struts of this structure are formed by those of the heat sinks that connect the yoke ring disk and the mounting tab base. The yoke ring disk and the mounting tab base are connected by this grid-like structure. The spaces within this grid-like structure, specifically at least the heat sink gaps located between the outer circumferential surface of the yoke ring disk and the mounting tab base, are open to coolant flow.Because the mounting tab is connected to the yoke ring disk via the grid-like structure, the radial gap is uninterrupted at points where the stator lamination stack has a mounting tab unit. This means that the outer surface of the stator lamination stack is exposed to coolant flow at these points, thus enabling cooling of the stator lamination stack at these locations.

[0014] In particular, the yoke ring disk, the heat sink structure, and the mounting lug unit, or at least one mounting lug, are formed from a single, monolithic material body. The yoke ring disk, the heat sink structure, and the mounting lug unit are manufactured together in a single production step, for example, by the laser cutting or stamping process described above. In the stator lamination stack, the stator laminations are connected, for example, by a tensile element that runs parallel to the longitudinal center axis of the lamination stack through a tensile element opening in the mounting lug(s) of the stator laminations. To mount the stator lamination stack in the stator housing in a rotationally fixed manner, the lamination stack chamber has, for example, a mounting lug receptacle that corresponds geometrically to the mounting lug, into which the mounting lug engages in a form-fitting manner.According to another possible embodiment of the stator lamination, the mounting tab assembly has two or more mounting tabs of identical shape, equidistant from one another along the stator lamination's circumferential direction u. In other words, the mounting tabs are evenly distributed along the outer circumference of the stator lamination. For example, the mounting tab assembly has four mounting tabs spaced 90 degrees apart along the stator lamination's circumferential direction u. The mounting tabs are identical; the yoke ring disk and the respective mounting tab are connected by connecting the radially inner base of each mounting tab to a radially outer end of two or more heat sinks.The mounting tabs are thus each materially bonded to the yoke ring disk by means of two or more heat sinks. In particular, the four mounting tabs are each arranged in one of the stator lamination quadrants, preferably on one of the angle bisectors between the coordinate axes x, y, z (see Fig. 1).

[0015] In another possible embodiment of the stator lamination, the spacing between the heat sinks along the circumferential direction u of the stator lamination is greater than one heat sink width, in particular twice or more than the heat sink width. This allows the coolant to flow particularly efficiently between the heat sinks, further promoting efficient heat transfer from the stator laminations to the coolant.

[0016] The stator lamination exhibits an even simpler geometry if – as a possible further development proposes – the heat sinks are equidistantly spaced from one another along the circumferential direction u of the stator lamination. This means that the heat sinks are evenly distributed around the circumference of the stator lamination. This results in a particularly uniform airflow around the outer surface of the stator lamination stack and, consequently, a particularly uniform heat dissipation from the stator lamination stack.

[0017] According to another possible embodiment – ​​reference is again made to Fig. 1 – the heat sink structure in the first stator lamination quadrant Q1 has a first number of heat sinks, whereas the heat sink structure in the second stator lamination quadrant Q2 has a second number of heat sinks, which is fewer than the first number. For example, it is provided that the heat sink structure in the first stator lamination quadrant Q1 has one fewer heat sink than in the second stator lamination quadrant Q2. Thus, it can be seen in Fig. 1 that a first heat sink of the first stator lamination quadrant Q1 is spaced a full heat sink distance from the Y-axis (transverse stator lamination axis) in the circumferential stator lamination direction u, and a last heat sink of the first stator lamination quadrant Q1 is spaced a full heat sink distance from the Z-axis (vertical stator lamination axis) in the circumferential stator lamination direction u.In contrast, a first heat sink of the second stator lamination quadrant Q2 is directly adjacent to the Z-axis (vertical axis of the stator lamination), and a last heat sink of the second stator lamination quadrant Q2 is directly adjacent to the Y-axis (transverse axis of the stator lamination). As further shown in Fig. 1, a radial heat sink center plane of the first heat sink of the first stator lamination quadrant Q1 and a radial heat sink spacing center plane of the first heat sink spacing of the second stator lamination quadrant Q2 are spaced apart by 90 degrees along the circumferential direction u of the stator lamination. The shapes of the first stator lamination quadrant Q1 and the second stator lamination quadrant Q2 define the other two stator lamination quadrants Q3 and Q4. This is because the first stator lamination quadrant Q1 and the third stator lamination quadrant Q3 are point-symmetric with respect to the stator lamination center M.Furthermore, the second stator lamination quadrant Q2 and the fourth stator lamination quadrant Q4 are point-symmetric with respect to the stator lamination center.

[0018] This design of the stator lamination offers a particular advantage, as it allows for the production of a stator lamination stack with an even larger outer surface area in a further development. In this design, the heat sinks and their spacing are offset along the longitudinal center axis of the lamination stack, while the stator laminations themselves remain identical components. Along the longitudinal center axis of the lamination stack, a first and a second heat sink spacing alternately overlap, with one of the heat sinks positioned centrally within the first or second heat sink spacing, respectively, when viewed along the longitudinal center axis. This component-based strategy makes the stator lamination particularly easy to manufacture and results in both environmentally friendly and cost-effective production.In a stator lamination stack, the stator laminations are individually and / or groups of stator laminations alternately rotated 90 degrees around the stack's longitudinal center axis or 180 degrees around a vertical or transverse axis that intersects the stack's longitudinal center axis. In other words, the stator lamination stack can contain stator laminations that are alternately rotated relative to each other. If we consider three stator laminations directly adjacent to each other along the stack's longitudinal center axis, the middle of these three stator laminations is rotated relative to the two outer stator laminations as described above. In particular, the stator lamination stack can be composed entirely of such individually rotated stator laminations. Furthermore, the stator lamination stack can contain groups of stator laminations, where such a group comprises two or more stator laminations, for example, ten stator laminations.The stator laminations of such a group are not twisted relative to each other, but the groups themselves are rotated relative to each other as described above. If one considers three stator lamination groups directly adjacent to each other along the longitudinal center axis of the lamination stack, the middle of these three stator lamination groups is rotated relative to the two outer stator lamination groups as described above. In particular, the stator lamination stack can be composed exclusively of such stator lamination groups rotated relative to each other. It is also conceivable that the stator lamination stack comprises a first lamination stack section with two or more individual stator laminations rotated relative to each other and a second lamination stack section with two or more stator lamination groups rotated relative to each other.

[0019] In the stator, the twisted individual stator laminations or stator lamination groups create a channel network between the inner surface of the stator core chamber and the outer circumferential surfaces of the stator laminations' root circles. This channel network is interspersed with the heat sinks. Due to the varying depths of the heat sinks, the heat sink structure forms an alternating high and low profile along both the stator lamination's circumferential direction (u) and the longitudinal center axis of the stator core. This causes the coolant to be deflected alternately in these three spatial directions. As a result, the coolant's fluid boundary layer is disrupted, causing it to flow turbulently rather than laminarly along the stator's outer surface—that is, along the inner and outer circumferential surfaces of the root circles—during operation of the stator or the electric machine.The cooling performance is significantly improved by the three-dimensional meandering channels compared to conventional stator cooling structures.

[0020] In another possible embodiment, the stator lamination stack does not have any additional type of lamination element arranged between two successive stator laminations along the longitudinal center axis of the stack. This further supports the idea of ​​a particularly simple design for the stator lamination stack.

[0021] According to an alternative embodiment, the stator lamination stack has a plurality of spacer stator laminations, each ending radially in front of the tip circumferential surface of the yoke circle ring disk, wherein one of the spacer stator laminations is arranged between two successive stator laminations along the longitudinal center axis of the lamination stack or between two stator lamination groups.

[0022] Further features of the invention may become apparent from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or on their own, without departing from the scope of the invention.

[0023] The drawing shows in Fig. 1 a sectional view of a stator of an electric machine whose stator lamination stack is made from a plurality of stator laminations, in Fig. 2 an enlarged view of a region n of the stator lamination stack marked in Fig. 1, in Fig. 3 a perspective view of the stator lamination stack, and in Fig. 4 an enlarged view of a region IV of the stator lamination stack marked in Fig. 3.

[0024] Stator lamination stack.

[0025] In the following, a stator lamination 1, a stator lamination stack 2 comprising the stator lamination 1, a stator 3 comprising the stator lamination stack 2, an electric machine comprising the stator 3, and a motor vehicle comprising the electric machine are described in a joint manner. The electric machine and the motor vehicle are not shown in the figures.

[0026] Identical and functionally equivalent elements are designated with the same reference numeral in the figures. Furthermore, the following reference is made to a coordinate system x, y, z, where the X-axis coincides with a longitudinal center axis 4 of the stator lamination 1 and a longitudinal center axis 5 of the stator lamination stack 2. The Y-axis coincides with a transverse axis 6 of the stator lamination 1 and a transverse axis 7 of the stator lamination stack 2, and the Z-axis coincides with a vertical axis 8 of the stator lamination 1 and a vertical axis 9 of the stator lamination stack 2. On the longitudinal center axis 4 of the stator lamination lies a stator lamination center point M of the stator lamination 1, specifically at half the thickness of the stator lamination 1. For the sake of clarity, only some of the stator teeth 11, stator slots 12, heat sinks 19, 20 and heat sink spacings 24, 25 described below are provided with the corresponding reference numeral.

[0027] The stator lamination stack 2 (see Fig. 3) is formed by a multitude of stator laminations 1, arranged along the longitudinal center axis 5 of the lamination stack. According to the present example, the stator laminations 1 are identical components, three of which are shown in Fig. 1, as will be explained in more detail later. The stator lamination stack 2 forms a component of the stator 3, and the stator 3 forms a component of the electric machine. The vehicle is a purely electric or hybrid-electric vehicle and therefore incorporates the electric machine as a traction machine.

[0028] Fig. 1 shows a sectional view of the stator 3 with the stator lamination stack 2. It can be seen in Fig. 1 that the stator laminations 1 each have a yoke ring disk 10, which has stator teeth 11 and stator grooves 12 on its inner circumference, arranged alternately. The stator teeth terminate radially on the inside at an inner circumferential surface 13 of the stator lamination or the yoke ring disk 10, which has an inner radius R1. The stator lamination 1 further has an inner, first outer circumferential surface 14, which is defined by a first root circle 15 (see Fig. 2) of the stator lamination 1, which has a root circle radius R2. Furthermore, the stator lamination 1 has an outer, second foot circle outer circumferential surface 16, which is defined by a second foot circle 17 (see Fig. 2) of the stator lamination 1, which has a foot circle radius R3.A heat sink structure 18 of the stator lamination 1 comprises a plurality of heat sinks 19, 20, each projecting radially outwards from the yoke ring disk 10 to a tip circle circumferential surface 21 of the stator lamination 1. The tip circle circumferential surface 21 is defined by a tip circle 22 (see Fig. 2) of the stator lamination 1, which has a tip circle radius R4. The following holds true for the radii R1, R2, R3, R4, each originating from the center M of the stator lamination: R1 < R2 < R3 < R4. Fig. 1 shows that, according to the present example, the heat sinks 19, 20 are each designed as a ridge at least substantially cuboid in shape, wherein a radially outer end face 23 of free heat sinks 19 can be arranged planarly and thus secantly or tangentially to the tip circle 22 of the stator lamination 1.Alternatively, the heat sink end face 23 can be shaped like a straight circular cylinder with a tip circle radius of R4, thus coinciding with the tip circle 22. Figure 1 also shows that the heat sinks 19, 20 are equidistant from one another along the stator lamination circumferential direction u. Therefore, the heat sink spacings 24, 25, by which two successive heat sinks 19, 20 are spaced apart along the stator lamination circumferential direction u, are equal. In this case, the heat sink spacings 24 are equal and each has a heat sink spacing dimension D that is greater than one heat sink width B of the heat sinks 19, 20 along the stator lamination circumferential direction u (D > B). In this case, the heat sink spacing dimension D is twice the heat sink width B or more (D > 2 - B). The heat sink width B and the heat sink spacing dimension D are in this case each one arc length of the head circle 22 of the stator lamination 1 or the yoke circle ring disk 10.

[0029] The heat sinks 19, 20 each have a long, first heat sink flank 26 and a short, second heat sink flank 27, with the first heat sink flanks 26 each resting on the inner outer circumferential surface 14 of the base circle, and the second heat sink flanks 27 each resting on the outer circumferential surface 16 of the base circle. The heat sink flanks 26, 27 are particularly well visible in Fig. 2. If one considers three heat sinks 19, 20 arranged directly one after the other along the circumferential direction u of the stator lamination, it can be seen that the heat sink spacings 24, 25 belonging to the three heat sinks 19, 20 are configured differently. Starting from the radial outer edge, or from the circumferential surface 21 of the head, the first heat sink spacing 24 has a greater radial depth than the second heat sink spacing 25. The deeper, or first, heat sink spacing 24 is bounded by two opposing, first—i.e., long—heat sink flanks 26. In contrast, the less deep, orThe second heat sink spacing 25 is bounded by two opposing second – i.e., short – heat sink flanks 27. As already explained, the first heat sink spacings 24 and the second heat sink spacings 25 are of equal length along the circumferential direction u of the stator lamination, thus each extending over an equal arc length of the yoke ring disk 10. Furthermore, the stator lamination 1 has a mounting lug unit 28, which has at least one mounting lug – in this case, four mounting lugs 29, 30, 31, 32. The mounting lugs 29, 30, 31, 32 each have a radially inner mounting lug base 33 and are equidistant from each other along the circumferential direction u of the stator lamination. The respective mounting tab base 33 of the mounting tabs 29, 30, 31, 32 is connected to a respective radially outer heat sink end 34 of two or more connecting heat sinks 20.The two or more connecting heat sinks 20 each form a connecting element by means of which the mounting tab 29, 30, 31, 32 and the yoke ring disk 10 are connected to one another. In the present design, it is provided that each mounting tab 29, 30, 31, 32 is connected to the yoke ring disk 10 by means of four or more connecting heat sinks 20. Furthermore, the mounting tabs 29, 30, 31, 32 each have a tensile opening 35. As can be seen in Fig. 1, the mounting tabs 29, 30 arranged in the first stator lamination quadrant Q1 and the third stator lamination quadrant Q3, and the mounting tabs 31, 32 arranged in the second stator lamination quadrant Q2 and the fourth stator lamination quadrant Q4, are point-symmetrical to each other with respect to the stator lamination center M. In addition, the mounting tabs 29, 30, 31, 32 are evenly distributed along the outer circumference u of the stator lamination.In the present case, the fastening tabs 29, 30, 31, 32 are spaced apart from each other by 90 degrees along the circumferential direction u of the stator sheet, in particular their tensile openings 35, which are each spaced apart by 45 degrees from both the X and Y axes.

[0030] The yoke ring disk 10, including the stator teeth 11 and stator grooves 12, the heat sink structure 18 (or heat sinks 19, 20), and the mounting bracket unit 28 (or mounting brackets 29, 30, 31, 32) are metallurgically bonded to one another. For example, the yoke ring disk 10, including the stator teeth 11 and stator grooves 12, the heat sink structure 18 (or heat sinks 19, 20), and the mounting bracket unit 28 (or mounting brackets 29, 30, 31, 32) are formed integrally, that is, machined from a single sheet metal blank, for example, by laser cutting. According to the embodiment described here, the stator sheet 1 is a stamped part or is manufactured by stamping. In other words: the yoke ring disk 10 together with the stator teeth 11 and stator grooves 12, the heat sink structure 18 or heat sink 19, 20 and the mounting lug unit 28 orMounting tabs 29, 30, 31, 32 and the tensile openings 35 are manufactured by a single stamping process, in particular by a single stamping stroke simultaneously. In the present example, the heat sink structure 18 has a first number of heat sinks N1 (i.e., a first number of heat sinks 19, 20) in the first stator lamination quadrant Q1, whereas the heat sink structure 18 has a second number of heat sinks N2 (i.e., a second number of heat sinks 19, 20) in the second stator lamination quadrant Q2, which is less than the first number of heat sinks N1 (N2 < N1). In this example, it is provided that the heat sink structure 18 has one fewer heat sink 19, 20 in the first stator lamination quadrant Q1 than in the second stator lamination quadrant Q2 (N2 = N1 - 1). As can be seen in Fig. 1, a first Q1 heat sink 19a in the first stator lamination quadrant Q1 extends in the stator lamination circumferential direction u over a complete heat sink spacing 25 ora last Q1 heat sink 19b is spaced a full heat sink spacing D from the Y-axis or stator lamination transverse axis 6, wherein a last Q1 heat sink 19b in the first stator lamination quadrant Q1 is spaced a full heat sink spacing 24 or 25 or a full heat sink spacing D from the Z-axis or stator lamination vertical axis 8 in the stator lamination circumferential direction u. In contrast, a first Q2 heat sink 19c in the second stator lamination quadrant Q2 is directly adjacent to the Z-axis or stator lamination vertical axis 8, and a last Q2 heat sink 19d in the second stator lamination quadrant Q2 is directly adjacent to the Y-axis or stator lamination vertical axis 8.

[0031] Stator lamination transverse axis 6. As further shown in Fig. 1, in this example, a radial heat sink center plane 36 of the first Q1 heat sink 19a and a radial heat sink spacing center plane 37 of a first Q2 heat sink spacing 24a arranged in the second stator lamination quadrant Q2 are spaced apart from each other along the stator lamination circumferential direction u by an angle a of 90 degrees. In other words, the center planes 36, 37 intersect each other perpendicularly, with the resulting line of intersection coinciding with the X or stator lamination longitudinal center axis 4.

[0032] It can be seen that the heat sink structure 18 is designed in a mirror-image, plane-symmetric form with respect to the heat sink center plane 36 or the heat sink spacing center plane 37, wherein the heat sink center plane 36 is tilted with respect to the Z or XY plane and the heat sink spacing center plane 37 is tilted with respect to the Y or XZ plane by the heat sink spacing dimension D in the stator lamination circumferential direction u.

[0033] The first stator lamination quadrant Q1 and the third stator lamination quadrant Q3 are point-symmetric with respect to the stator lamination center M, while the second stator lamination quadrant Q2 and the fourth stator lamination quadrant Q4 are point-symmetric with respect to the stator lamination center M. Thus, stator lamination 1 has the same geometric configuration in the first stator lamination quadrant Q1 as in the third stator lamination quadrant Q3. Similarly, stator lamination 1 has the same geometric configuration in the second stator lamination quadrant Q2 as in the fourth stator lamination quadrant Q4.

[0034] Fig. 3 shows the stator lamination stack 2 in a perspective view, with the stator laminations 1 arranged along the longitudinal center axis 5 of the lamination stack being alternately rotated by 90 degrees about the longitudinal center axis of the lamination stack. Given the geometry of the individual stator lamination 1 described so far, it is equally conceivable that the stator laminations 1 of the stator lamination stack 2 arranged along the longitudinal center axis 5 of the lamination stack are instead alternately rotated by 180 degrees about the vertical axis 9 or transverse axis 7 of the lamination stack, which intersects the longitudinal center axis 5 of the lamination stack perpendicularly. In any case, it can be clearly seen in Fig. 3 and especially in the illustration of Fig. 4 that the stator laminations 1 are arranged along the longitudinal center axis 5 of the lamination stack such that the heat sinks 19, 20 of two stator laminations 1 directly adjacent to each other along the X or longitudinal center axis 5 of the lamination stack are arranged axially (i.e. in relation to the X or longitudinal center axis 5 of the lamination stack) offset from each other.An axial view of the stator lamination stack 2 reveals that a heat sink 19, 20 of the subsequent stator lamination 1 is arranged at the heat sink spacings 24, 25 of the respective stator lamination 1. Starting from a first stator lamination 1, the following sequence results for the stator lamination quadrants Q1, Q2, Q3, Q4 stacked on the first stator lamination quadrant Q1 along the X-axis or longitudinal center axis 5 of the lamination stack: Q1 (first stator lamination 1), Q2, Q1, Q2, etc., or Q1 (first stator lamination 1), Q4, Q1, Q4, etc.

[0035] In this example, the stator lamination stack 2 has no other type of lamination element besides the stator laminations 1 that is arranged between two successive stator laminations 1 along the longitudinal center axis 5 of the lamination stack. Alternatively, the stator lamination stack 2 can have a plurality of spacer stator laminations (not shown) that terminate radially inside, each in front of the tip circumferential surface 21 of the yoke ring disk 10, with one or more of the spacer stator laminations being arranged between each pair of successive stator laminations 1 along the longitudinal center axis 5 of the lamination stack, or between two stator lamination groups, each of which has two or more stator laminations 1 and / or one or more spacer laminations.

[0036] Referring again to Fig. 1, it can be seen that the stator 3 has a stator housing 38, wherein a lamination stack chamber 39 of the stator 3 or stator housing 38 is bounded by an inner surface 40 of the stator housing 38. The lamination stack chamber 39 or the inner surface 40 has four mounting tab receptacles 41, each of which geometrically corresponds to the mounting tabs 29, 30, 31, 32 to form a positive fit. The stator lamination stack 2, comprising the stator laminations 1, is mounted in the lamination stack chamber 39 in a rotationally fixed manner by the mounting tabs 29, 30, 31, 32 each engaging positively in one of the mounting tab receptacles 41. In this process, the longitudinal center axis 5 of the stator lamination stack 2 and a longitudinal center axis 42 of the lamination stack chamber 39 coincide.

[0037] A radial gap 43 is formed between the inner surface 40 of the stator housing 38 and the respective tip circumferential surface 21 of the stator laminations 1, into which the heat sinks 19, 20 project radially. Due to the geometry of the stator laminations 1, the radial gap 43 continues under the mounting tabs 29, 30, 31, 32 and between the respective mounting tab base 33 and the outer circumferential surfaces 14, 16. As can be seen in Fig. 1, in the area of ​​the mounting tabs 29, 30, 31, 32, the radial gap 43 is effectively covered radially by the corresponding mounting tab base 33, whereas away from the mounting tabs 29, 30, 31, 32, the radial gap 43 is covered radially by the inner surface 40 of the lamination stack chamber 39.

[0038] During operation of the electric machine, which has a stator 3, a coolant (here, a cooling oil in this example) is introduced into the stator 3, specifically into the radial gap 43, to cool the stator 3 or to directly cool the stator lamination stack 2. The coolant flows directly along an outer surface 44 of the stator lamination stack 2, which is composed of the outer circumferential surfaces 45 of the stator laminations 1. Due to the heat sink structure 18, the respective outer circumferential surface 45 is particularly large, and the coolant flows around the heat sinks 19, 20. Furthermore, the coolant also flows directly along the outer surface 44 and the heat sinks 19, 20 in the area of ​​the mounting tabs 29, 30, 31, 32. According to the example described above, the stator housing 38 has a coolant inlet opening 46 and a coolant outlet opening 47, both of which open into the laminated core chamber 39 and consequently into the radial gap 43.By means of these coolant openings 46, 47, the stator housing 38 or the electric machine can be fluidically integrated into a coolant circuit, in particular into an oil circuit of the motor vehicle. This enables particularly efficient, direct liquid cooling of the stator 3 or stator lamination stack 2, thereby solving the problem set out at the beginning, namely to create a solution for particularly efficient direct stator cooling.

[0039] The invention is based on the idea of ​​increasing and further structuring the outer surface area 44 of the stator lamination stack 2 in order to promote heat transfer from the material of the stator lamination stack 2 or the stator laminations 1. The structuring of the outer surface area 44 – that is, by the heat sink structure 18 – also improves heat transport through turbulent mixing of the coolant flow. The fluid flow is deflected three-dimensionally, i.e., both along the longitudinal center axis 5 of the lamination stack to the right and left past the heat sinks 19, 20 and the heat sink flanks 26, 27 (tangentially), and also upwards and downwards along the longitudinal center axis 5 of the lamination stack due to the different depths of the heat sinks 24, 25 (radially).This three-dimensional meandering structure is also continued in the area of ​​the mounting tabs 29, 30, 31, 32 and simultaneously functions as a connecting element by which the mounting tabs 29, 30, 31, 32 are connected to the yoke ring disks 10. The coolant flows between the outer shell surface 44 and the mounting tab bases 33. These measures enable a particularly high continuous power output of the electric machine according to the invention and lead to better material utilization with an increase in power density and cost structure.

[0040] Reference symbol list

[0041] 1 stator lamination

[0042] 2 Stator lamination package

[0043] 3 Stator

[0044] 4 Stator lamination longitudinal center axis

[0045] 5 sheet metal package longitudinal center axis

[0046] 6 Stator lamination transverse axis

[0047] 7 Sheet metal package transverse axis

[0048] 8 Stator lamination vertical axis

[0049] 9 sheet metal package vertical axis

[0050] 10 Yoke circle ring disc

[0051] 11 Stator tooth

[0052] 12 Stator slots

[0053] 13 Inner perimeter area

[0054] 14 inner, first outer circumference of the foot

[0055] 15 first foot circle

[0056] 16 outer, second foot circle outer circumferential area

[0057] 17 second foot circle

[0058] 18 Heat sink structure

[0059] 19 heat sinks

[0060] 19a first Q1 heat sink

[0061] 19b last Q1 heat sink

[0062] 19c first Q2 heatsink

[0063] 19d last Q2 heat sink

[0064] 20 connecting heat sinks

[0065] 21 Head circumference area

[0066] 22 Head Circle

[0067] 23 Heat sink end surface

[0068] 24 first heat sink spacing

[0069] 24a first Q2 heat sink spacing

[0070] 25 second heat sink spacing

[0071] 26 long, first heatsink flank 27 short, second heatsink flank

[0072] 28 fastening tab unit

[0073] 29 Mounting tab

[0074] 30 fastening tab

[0075] 31 Mounting tab

[0076] 32 Mounting tab

[0077] 33 Mounting tab base

[0078] 34 Heat sink end

[0079] 35 Traction opening

[0080] 36 Heat sink center level

[0081] 37 Heat sink spacing center plane

[0082] 38 Stator housings

[0083] 39 Sheet metal parcel chamber

[0084] 40 inner surface area

[0085] 41 Mounting tab receptacle

[0086] 42 sheet metal stack chamber longitudinal center axis

[0087] 43 Radial gap

[0088] 44 Outer shell area

[0089] 45 external perimeter area

[0090] 46 Coolant inlet opening

[0091] 47 Coolant outlet

[0092] B Heat sink width

[0093] D Heat sink spacing dimension

[0094] M Stator lamination center

[0095] N1, N2 Number of heat sinks

[0096] Q1-Q4 Stator lamination quadrant

[0097] R1 inner radius

[0098] R2 first foot circle radius

[0099] R3 second foot circle radius

[0100] R4 Head circle radius u Stator lamination circumferential direction a Angle

Claims

Patent claims 1. Stator lamination (1) for a stator lamination stack (2) of an electric machine, wherein the stator lamination (1) comprises: - a yoke circle ring disk (10) with an inner base circle outer circumferential surface (14) and with an outer base circle outer circumferential surface (16), - a heat sink structure (18) whose heat sinks (19, 20) each - project radially outwards to a tip circumferential surface (21) of the yoke circle ring disk (10) and are spaced apart from each other along a stator lamination circumferential direction (u) by a heat sink spacing (24, 25), - having a long, first heat sink flank (26) and a short, second heat sink flank (27), wherein the first heat sink flanks (26) each have their base on the inner outer circumferential surface (14) of the base circle, and the second heat sink flanks (27) each have their base on the outer circumferential surface (16) of the base circle, wherein one of two heat sink distances (24, 25) which are arranged directly one after the other along the circumferential direction (u) of the stator lamination is bounded by two opposing first heat sink flanks (26), and the corresponding other of the heat sink distances (24, 25) is bounded by two opposing second heat sink flanks (27).

2. Stator lamination (1) according to claim 1, characterized in that it is formed in one piece, in particular as a stamped part.

3. Stator lamination (1) according to claim 1 or 2, characterized by a mounting tab unit (28) whose mounting tab (29, 30, 31 32) is connected to the yoke ring disk (10) at the head circumferential surface (21) by connecting a radially inner mounting tab base (33) of the mounting tab (29, 30, 31 , 32) to a respective radially outer heat sink end (34) of two or more heat sinks (19, 20).

4. Stator lamination (1) according to claim 3, characterized in that the fastening lug unit (28) has two or more fastening lugs (29, 30, 31, 32) of the same shape, in particular four fastening lugs (29, 30, 31, 32) which are equidistant from each other along the circumferential direction (u) of the stator lamination.

5. Stator lamination (1) according to one of the preceding claims, characterized in that a heat sink spacing dimension (D) of the heat sink spacing (24, 25) along the circumferential direction (u) of the stator lamination is more than a heat sink width (B), in particular twice or more than the heat sink width (B).

6. Stator lamination (1) according to one of the preceding claims, characterized in that the cooling elements (19, 20) are equidistantly spaced apart from each other along the circumferential direction (u) of the stator lamination.

7. Stator lamination (1) according to claims 5 and 6, characterized in that - the heat sink structure (18) in a first stator lamination quadrant (Q1) of the stator lamination (1) has a first number of heat sinks (N1), - the heat sink structure (18) in a second stator lamination quadrant (Q2) of the stator lamination (1) has a second number of heat sinks (N2) that is less than the first number of heat sinks (N1), in particular by one less, - a radial heat sink center plane (36) of a first heat sink (19a) of the first stator lamination quadrant (Q1) and a radial heat sink spacing center plane (37) of a first heat sink spacing (24a) of the second stator lamination quadrant (Q2) are spaced apart by 90 degrees along the stator lamination circumferential direction (u), - the first stator lamination quadrant (Q1) and a third stator lamination quadrant (Q3) of the stator lamination (1) are point-symmetric with respect to a stator lamination center (M), - the second stator lamination quadrant (Q2) and a fourth stator lamination quadrant (Q4) of the stator lamination (1) are point-symmetric with respect to the stator lamination center (M).

8. Stator lamination stack (2) for a stator (3) of an electric machine, comprising a plurality of stator laminations (1) designed according to one of the preceding claims, arranged along a longitudinal center axis (5) of the lamination stack.

9. Stator lamination stack (2) according to claim 8, characterized in that the stator laminations (1) each have the features specified in claim 7, wherein the stator laminations (1) are individually and / or groups of stator laminations (1) alternately rotated about the longitudinal center axis (5) of the lamination stack by 90 degrees or about a vertical axis (9) or transverse axis (7) of the lamination stack intersecting the longitudinal center axis (5) of the lamination stack by 180 degrees.

10. Stator lamination stack (1) according to claim 8 or 9, characterized in that no other lamination element is arranged between two successive stator laminations (1) along the longitudinal center axis (5) of the lamination stack.

11. Stator lamination stack (1) according to claim 8 or 9, characterized by a plurality of spacer stator laminations which each end radially in front of the tip circumferential surface (21) of the yoke circle ring disk (10), wherein one of the spacer stator laminations is arranged between each of two successive stator laminations (1) along the longitudinal center axis (5) of the lamination stack.

12. Stator (3) for an electric machine, comprising: - a stator housing (38) whose laminated core chamber (39) is bounded by an inner surface (40) of the stator housing (38), - the stator lamination stack (2) designed according to one of claims 8 to 11, which is mounted in the lamination stack chamber (39) in a rotationally fixed coaxial manner, such that a radial gap (43) is formed between the inner shell surface (40) and the head circumferential surface (21), into which the cooling elements (19, 20) project radially.

13. Stator (3) according to claim 12, characterized in that the stator housing (38) has a coolant inlet opening (46) and a coolant outlet opening (47), both of which open into the laminated core chamber (39) and consequently into the radial gap (43).

14. Electric machine with a stator (3) designed according to claim 12 or 13.

15. Motor vehicle with an electric machine designed according to claim 14.

Images