Stator of an electric machine

Abstract

The invention relates to a stator of an electric machine (2), having a stator laminated core (3) which comprises a stack of laminations (4) and on which, along the outer circumference thereof, at least one form-fitting element (5), in particular a form-fitting slot and / or form-fitting tooth, is formed that is provided for fastening the stator to a machine housing (6) and is each designed to form a press-fit with a mating form-fitting element (15), in particular a housing tooth or housing slot on the machine housing (6), or with an intermediate element (16), in particular a slot nut, wherein the particular form-fitting element (5) has two opposing flanks (5f) for interaction with the associated mating form-fitting element (15) or with the associated intermediate element (16) and extends in particular in the axial direction with respect to a stator axis (1a), characterized in that at least one flank (5f) of the particular form-fitting element (5) has a flank rib system (10) that comprises projecting ribs (11) and portions (12) that are set back in relation to the projecting ribs (11).

Description

[0001] Description

[0002] title

[0003] Stator of an electric machine

[0004] State of the art

[0005] The invention relates to a stator of an electrical machine according to the preamble of the main claim.

[0006] A stator of an electric machine is already known from EP3748816 A1, comprising a stator lamination stack with a stack of laminations and several positive locking elements, in particular positive locking teeth, formed along its outer circumference. These positive locking elements are designed for fixing the stator to a machine housing and are each configured to form a contact with a corresponding positive locking element. The positive locking elements, designed as positive locking teeth, each have two opposing flanks for interacting with the corresponding positive locking element and extend, in particular, in the axial direction with respect to a stator axis. The corresponding positive locking elements are grooves in the machine housing.The pressure between the positive locking teeth of the stator lamination stack and the housing grooves of the machine housing can cause mechanical stresses in the stator lamination stack, which negatively affect the magnetic properties of the laminations, thus reducing the power of the electric machine.

[0007] Advantages of the invention

[0008] In contrast, the stator of an electric machine according to the invention, with the characterizing features of the main claim, has the advantage that it provides a stator fixing that generates fewer mechanical stresses in the stator lamination stack and thus impairs the magnetic properties of the laminations less. This allows the power output of the electric machine to be further increased. According to the invention, this is achieved by having at least one flank of the respective positive-locking element have flank ribbing comprising projecting ribs and recessed sections.

[0009] Due to the flank ribbing according to the invention, fewer stresses are generated in the stator lamination stack than in the prior art, because only a part of the lamination plates of the stator lamination stack is locally subjected to pressure per positive locking element.

[0010] The stator fixing also has lower tolerance requirements, allowing for increased joining tolerances. This eliminates the need for post-processing of the stator lamination stack to meet joining tolerances. Furthermore, no heating of either component is required to join the stator fixing. Overall, this can reduce manufacturing costs.

[0011] The measures listed in the dependent claims enable advantageous further developments and improvements of the stator of an electrical machine specified in the main claim.

[0012] It is particularly advantageous if both flanks of the respective positive locking element have flank ribbing. In this way, very low joining forces can be achieved for joining the stator fixing.

[0013] It is highly advantageous if the ribs and recessed sections of the respective flank ribbing are formed on different laminations and arranged axially in such a way that at least two separate gaps are formed on each flank, into which an adjacent rib can be bent. This makes the flank ribbing more easily deformable. Part of the bending deformation is elastic. The stator can therefore be joined with lower joining forces than in the prior art, resulting in even less stress being generated locally in the stator lamination stack and further minimizing the degradation of the magnetic properties of the laminations.

[0014] It is further advantageous if the ribs of the respective flank ribs are designed to form a contact with a mating element or intermediate element. It is also advantageous if recessed sections of the respective flank are provided relative to the ribs to form a joint clearance with the mating element or intermediate element. In this way, only a portion of the laminations of the stator core is subjected to local pressure for each mating element, thereby generating fewer stresses in the stator core.

[0015] It is advantageous if several, and in particular all, sheet metal laminations have several contour elements on their outer circumference, especially lamination recesses and / or lamination teeth, to form at least one positive locking element. In this way, the contour elements of the stacked sheet metal laminations can form the at least one positive locking element on the outer circumference of the stator lamination stack.

[0016] It is also advantageous if the respective contour element of the respective sheet metal lamella forms a. a rib on one flank and a recessed section on the other flank, or b. a rib or a recessed section on both flanks. According to these advantageous variants, the flank ribbing can be produced very simply.

[0017] Furthermore, it is advantageous if, according to one variant, the contour elements of the respective sheet metal lamella have the same width and are arranged at different angular intervals along the circumference, or, according to another variant, if they have two different widths and are arranged at the same angular intervals along the circumference. According to this further variant, the first width of a contour element is used to create a pressure point, and the second width of a contour element is used to create a joint clearance. In this way, the side ribbing can be produced very easily.

[0018] Furthermore, it is advantageous if the sheet metal laminations are formed congruently with contour elements and are each rotated by an angle around the stator axis and / or arranged laterally reversed to form the flank ribbing. In this way, the flank ribbing can be produced with only one type of sheet metal lamination, so that only one stamping tool is required to cut this type of lamination. It is also advantageous if cooling channels, in particular cooling grooves, are provided between the positive locking elements of the stator, especially if they extend in the axial direction. In this way, in addition to stator fixation, stator cooling can be implemented on the outer circumference of the stator lamination stack.

[0019] The invention further relates to a machine arrangement comprising a machine housing and a stator according to the invention arranged in the machine housing. The machine housing has at least one mating positive-locking element, in particular a housing groove or a housing tooth, for direct or indirect interaction with a positive-locking element of the stator. A press fit is provided between the respective positive-locking element of the stator and the associated mating positive-locking element of the machine housing. Alternatively, an intermediate element, in particular a T-nut, can be arranged with a press fit in the respective positive-locking element and the respective mating positive-locking element.

[0020] Several positive locking elements and counter-locking elements can be arranged along the circumference of the machine arrangement, in particular with the same angular spacing.

[0021] drawing

[0022] Exemplary embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description.

[0023] They show:

[0024] Fig. 1 shows a stator according to a first embodiment, which has three slot-shaped positive locking elements on its outer circumference, into which slot blocks for fixing the stator to a machine housing can be pressed.

[0025] Fig. 2 shows a partial view of one of the groove-shaped positive locking elements of the stator.

[0026] Fig. 1 with flank ribbing according to the invention,

[0027] Fig. 3 shows a sheet metal lamella of the stator according to Fig. 1 with contour elements for forming the positive locking elements, Fig. 4 shows a variant of the flank ribbing according to the invention according to Fig. 2, Fig. 5 shows a further variant of the flank ribbing according to the invention according to Fig. 2, Fig. 6 shows a stator according to a second embodiment, which has three tooth-shaped positive locking elements on its outer circumference that can be pressed into housing grooves of the machine housing and

[0028] Fig. 7 shows a partial view of one of the tooth-shaped positive locking elements of the stator according to Fig. 6 with flank ribbing according to the invention.

[0029] Description of the exemplary implementations

[0030] Fig. 1 shows a stator according to a first embodiment, which has three slot-shaped positive locking elements on its outer circumference, into which slot blocks for fixing the stator to a machine housing can be pressed.

[0031] The stator 1 of an electric machine 2 has a stator lamination stack 3, which comprises a stack of laminations 4 and on which at least one positive locking element 5, in particular a positive locking groove and / or a positive locking tooth, is formed along its outer circumference. The respective positive locking element 5 is provided for fixing the stator to a machine housing 7. The respective positive locking element 5 can be configured to form a press fit with a counter-positive locking element 15, in particular a housing tooth or a housing groove of the machine housing 7, or, as shown in Fig. 1, to form a press fit with an intermediate element 16, in particular a T-nut. The machine housing 7 has at least one counter-positive locking element 15 for direct or indirect interaction with a positive locking element 5 of the stator 1. The machine housing 7 and the stator 1 arranged in the machine housing 7 form a machine assembly 20.

[0032] According to Fig. 1, the machine housing 7 has several mating locking elements 15 along its inner circumference, in particular housing grooves, for direct or indirect interaction with the mating elements 5 of the stator 1. The multiple mating elements 5 and mating locking elements 15 are arranged along the circumference of the machine assembly, in particular with the same angular spacing a. The intermediate elements 16, in particular T-nuts, are arranged with a press fit in the mating elements 5 and the mating locking elements 15.

[0033] The stator fixing can serve to support the torque of the stator 1 on the machine housing 7 or to align the stator 1 in the machine housing 7.

[0034] The stator lamination stack 3 has, for example, several positive locking elements 5 along its outer circumference, three positive locking elements 5 as shown in Fig. 1. The positive locking elements 5 are, for example, groove-shaped as shown in Fig. 1. Each positive locking element 5 has two opposing flanks 5f for interacting with the respective counter-positive locking element 15 or with the respective intermediate element 16 and extends, in particular, in the axial direction with respect to a stator axis 1a. A perpendicular line on each flank 5f points in the circumferential direction.

[0035] Cooling channels 8, in particular cooling grooves, can be provided in the circumferential direction between the positive locking elements 5 of the stator 1, extending particularly in the axial direction. However, the cooling channels 8 can also be omitted.

[0036] The laminations 4 of the stator lamination stack 3 are firmly connected to each other, for example by gluing or interlocks.

[0037] Fig. 2 shows a partial view of one of the groove-shaped positive locking elements of the stator according to Fig. 1 with flank ribbing according to the invention.

[0038] According to the invention, at least one flank 5f of the respective positive locking element 5 has a flank ribbing 10 comprising projecting ribs 11 and recessed sections 12 relative to the projecting ribs 11.

[0039] According to the first embodiment in Fig.2, both flanks 5f of the respective positive locking element 5 have a flank ribbing 10.

[0040] The projecting ribs 11 of the respective flank ribbing 10 are designed to form a press fit with a counter-form-locking element 15 or an intermediate element 16. The recessed sections 12 of the respective flank 5f, relative to the ribs 11, are designed to form a joint clearance with the counter-form-locking element 15 or intermediate element 16.

[0041] The ribs 11 and recessed sections 12 of the respective flank ribbing 10 are formed on different sheet metal lamellae 4 according to Fig. 2, Fig. 4 and Fig. 5 and are arranged in an axial direction with respect to the stator axis 1a in such a way that at least two separate gap spaces 13 are formed on the respective flank 5f, into which an adjacent rib 11 can be bent.

[0042] The stator 1 has stator teeth 14 on its inner circumference, the tooth flanks 14f of which are unribbed. The flank ribbing 10 is thus formed without creating a ribbing of the tooth flanks 14f of the stator teeth 14.

[0043] The transition 17 from the respective flank 5f of the respective groove-shaped form-locking element 5 to a groove base 5g is, for example, designed in the form of an undercut.

[0044] Fig. 3 shows a sheet metal lamella of the stator according to Fig. 1 with contour elements for forming the positive locking elements.

[0045] Several, in particular all, sheet metal laminations 4 of the stator lamination stack 3 have several contour elements 6 on their outer circumference according to Fig. 3, in particular lamination recesses and / or lamination teeth, to form a positive locking element 5 in the stator lamination stack 3.

[0046] In the circumferential direction between the contour elements 6 of the respective sheet metal lamella 4, cooling elements 9, in particular lamella recesses, can be provided to form the cooling channels 8 in the stator lamination stack 3.

[0047] Fig. 4 shows a variant of the flank ribbing according to the invention as shown in Fig. 2.

[0048] Fig. 4 shows sheet metal lamellae 4.1 in which the respective contour element 6 of the respective sheet metal lamella 4.1 forms a rib 11 on both flanks 6f. Fig. 4 also shows sheet metal lamellae 4.2 in which the respective contour element 6 of the respective sheet metal lamella 4.2 forms a recessed section 12 on both flanks 6f. The sheet metal lamellae 4 with contour elements 6 according to Fig. 4 are congruent, i.e., of the same sheet metal lamella type. To form the flank ribbing 10, the sheet metal lamellae 4 are each rotated by an angle of rotation about the stator axis 1a and / or arranged laterally reversed.

[0049] The several contour elements 6 of the respective sheet metal lamella 4 have, according to Fig. 4, two different widths b and are arranged with the same angular distance ß along the circumference, with a first width b1 being provided to form a pressure and a second width b2 being provided to form a joint clearance.

[0050] Fig. 5 shows another variant of the flank ribbing according to the invention as shown in Fig. 2.

[0051] Fig. 5 shows sheet metal lamellae 4.3, in which the respective contour element 6 of the respective sheet metal lamella 4.3 forms a rib 11 on one flank 6f and a recessed section 12 on the other flank 6f. Furthermore, Fig. 5 shows sheet metal lamellae 4.4, in which the respective contour element 6 of the respective sheet metal lamella 4.4 forms a recessed section 12 on both flanks 6f.

[0052] The sheet metal lamellae 4 with contour elements 6 according to Fig. 5 are also identical, i.e., of the same sheet metal lamella type. To form the flank ribbing 10, the sheet metal lamellae 4 are each rotated by an angle of rotation about the stator axis 1a and / or arranged laterally reversed.

[0053] According to Fig. 5, the several contour elements 6 of the respective sheet metal lamella 4 have the same width b and are arranged with different angular distances ß along the circumference.

[0054] Fig. 6 shows a stator according to a second embodiment, which has three tooth-shaped positive locking elements on its outer circumference that can be pressed into housing grooves of the machine housing.

[0055] According to the second embodiment, the positive locking elements 5 are tooth-shaped.

[0056] The respective positive locking element 5 is designed according to Fig. 6 to form a press fit with a counter-positive locking element 15, in particular a housing groove of the machine housing 7. The intermediate elements 16 from the first embodiment are omitted in the second embodiment.

[0057] Fig. 7 shows a partial view of one of the tooth-shaped positive locking elements of the stator according to Fig. 6 with flank ribbing according to the invention.

[0058] According to the second embodiment, several, in particular all, sheet metal laminations 4 of the stator lamination stack 3 have tooth-shaped contour elements 6 on their outer circumference to form a positive locking element 5 in the stator lamination stack 3. The contour elements 6 are therefore laminar teeth.

[0059] Even in the second embodiment, at least one flank 5f of the respective positive locking element 5 has a flank ribbing 10 according to the invention. According to Fig. 7, both flanks 5f have a flank ribbing 10.

[0060] The flank ribbing 10 is produced in the same way as in the first embodiment.

Claims

Claims 1. Stator of an electric machine (2) with a stator lamination stack (3) comprising a stack of laminations (4) and on which at least one positive locking element (5), in particular a positive locking groove and / or positive locking tooth, is formed along its outer circumference, which is provided for fixing the stator to a machine housing (7) and is configured to form a press fit with a counter-positive locking element (15), in particular a housing tooth or a housing groove of the machine housing (7), or with an intermediate element (16), in particular a T-nut, wherein the respective positive locking element (5) has two opposing flanks (5f) for interacting with the respective counter-positive locking element (15) or with the respective intermediate element (16) and extends in particular in an axial direction with respect to a stator axis (1a), characterized in thatthat at least one flank (5f) of the respective positive locking element (5) has a flank ribbing (10) comprising projecting ribs (11) and recessed sections (12) relative to the projecting ribs (11).

2. Stator according to claim 1, characterized in that both flanks (5f) of the respective positive locking element (5) have flank ribbing (10).

3. Stator according to one of the preceding claims, characterized in that the ribs (11) and recessed sections (12) of the respective flank ribbing (10) are each formed on different sheet metal lamellae (4) and are arranged in an axially distributed manner such that at least two separate gap spaces are formed on the respective flank (5f), into which an adjacent rib (11) can be bent.

4. Stator according to one of the preceding claims, characterized in that the projecting ribs (11) of the respective flank ribbing (10) are provided for forming a press fit with a counter-form-locking element (15) or intermediate element (16) and that the recessed sections (12) of the respective flank (5f) are provided for forming a joining clearance to the counter-form-locking element (15) or intermediate element (16).

5. Stator according to one of the preceding claims, characterized in that several, in particular all, sheet metal lamellae (4) have several contour elements (6), in particular lamella recesses and / or lamella teeth, on their outer circumference to form the at least one positive locking element (5).

6. Stator according to claim 5, characterized in that the respective contour element (6) of the respective sheet metal lamella (4) forms a. a rib (11) on one flank (6f) and a recessed section (12) on the other flank (6f) or b. a rib (11) or a recessed section (12) on both flanks (6f).

7. Stator according to one of claims 5 or 6, characterized in that the contour elements (6) of the respective sheet metal lamella (4) a. have the same width (b) and are arranged with different angular spacing (β) along the circumference b. have two different widths and are arranged with the same angular spacing (β) along the circumference, wherein a first width (b1) is provided to form a pressure and a second width (b2) is provided to form a joint clearance.

8. Stator according to one of claims 5 to 7, characterized in that the sheet metal lamellae (4) are formed congruently with contour elements (6) and are each rotated by an angle of rotation about the stator axis (1 a) and / or arranged in reverse to form the flank ribbing (10).

9. Stator according to one of the preceding claims, characterized in that cooling channels (8), in particular cooling grooves, are provided between the positive locking elements (5) of the stator (1), which extend in particular in the axial direction.

10. Machine arrangement comprising a machine housing (7) and a stator (1) arranged in the machine housing (7) according to one of the preceding claims, wherein the machine housing (7) has at least one mating positive locking element (15), in particular a housing groove or a housing tooth, for direct or indirect cooperation with a a positive locking element (5) of the stator (1), wherein a pressing is provided between the respective positive locking element (5) of the stator (1) and the associated counter-positive locking element (15) of the machine housing (7), or wherein an intermediate element (16), in particular a T-nut, is arranged with a pressing in the respective positive locking element (5) and the respective counter-positive locking element (15).

11. Machine arrangement according to claim 10, characterized in that several positive locking elements (5) and counter-positive locking elements (15) are arranged along the circumference of the machine arrangement, in particular with the same angular distance (a).

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