Stator of an electric machine

Abstract

The invention relates to a stator of an electric machine (2) comprising a laminated core (3) which comprises laminations (4, 4.1, 4.2, 4.3) and which has stator teeth (5) and stator slots (6) lying between the stator teeth (5) and extends about a stator axis (7). The stator also comprises a stator winding (8) running in the stator slots (6), wherein the stator teeth (5) are connected to one another via an annular stator yoke (9), and each stator tooth has a tooth end (10) facing away from the stator yoke (9), said tooth end being designed as a tooth head; the stator slots (6) have slot openings (12) formed between the respective tooth heads (10), and the slot openings (12) of the laminated core (3) are closed by means of at least one slot closure (13); and a cooling medium, in particular oil, can flow along a cooling path (14) through each of the stator slots (6). The invention is characterized in that each slot closure (13) is a sealing cord which is positioned in at least one of the slot openings (12) and is held there by means of a tension between two tooth head flanks (15) of two stator teeth (5).

Description

[0001] Description

[0002] title

[0003] Stator of an electrical machine

[0004] State of the art

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

[0006] A stator of an electrical machine is already known from DE102018101640 A1, comprising a stator core comprising laminations, which has stator teeth and stator slots located between the stator teeth and extends around a stator axis, and with a stator winding running in the stator slots. The stator teeth are connected to one another via an annular stator yoke and each has a tooth end facing away from the stator yoke, which is designed as a tooth tip. The stator slots have slot slots formed between the respective tooth tips. The slot slots of the stator core are closed by a sleeve-shaped slot closure located on an inner circumference of the stator core. A cooling medium, in particular oil, can flow through the stator slots along a cooling path.The disadvantage is that the sleeve-shaped slot closure increases the air gap between the stator and the rotor of the electrical machine, which reduces the performance of the electrical machine.

[0007] Advantages of the invention

[0008] The stator of an electrical machine according to the invention with the characterizing features of the main claim has the advantage that the slot closure is formed in the slot slots and thus outside the air gap, whereby the performance of the electrical machine can be increased.

[0009] This is achieved according to the invention in that the respective slot closure is a sealing cord that is inserted into at least one of the slot slots and held there by a clamping force between two tooth tip flanks of two stator teeth. The clamping of the sealing cord in the respective slot slot seals the respective stator slot against the air gap.

[0010] The sealing cord can have any cross-section, in particular round, oval, or square. The measures listed in the subclaims allow advantageous refinements and improvements of the stator of an electrical machine specified in the main claim.

[0011] It is particularly advantageous if the tooth tip flanks each have a recessed flank contour that extends axially relative to the stator axis and is designed to partially accommodate the respective sealing cord, in particular having a groove-like or groove-like design. In this way, the sealing cord is held in a predetermined position.

[0012] According to an advantageous first embodiment, a press fit is provided to produce the tension of the respective sealing cord, wherein the respective sealing cord is designed to be elastic, in particular made of an elastomer.

[0013] According to the first embodiment, the respective sealing cord can be inserted into the respective groove slot in a state of elastic elongation, reducing its cross-section. This allows the sealing cord to be installed in the groove slot easily and without friction. The tension in the sealing cord is achieved by the subsequent relaxation of the elastically elongated sealing cord.

[0014] According to an advantageous second embodiment, the material of the sealing cord can be an expandable material, in particular a thermally expandable material or a material expandable by light or pressure. This allows the sealing cord to be inserted into the groove slot easily and without friction and to be tightened in the respective groove slot by subsequent expansion.

[0015] It is very advantageous if a single sealing cord or multiple sealing cords are provided for closing the stator slot slots. To close multiple slot slots, the sealing cord can be routed in a meandering pattern through several, particularly all, slot slots. This reduces the number of parts to be joined, which can simplify manufacturing and improves the mechanical fixation of the sealing cord.It is also advantageous if at least one set of three oppositely rotated first stator sub-packages is provided in the stator package for clamping the stator winding at clamping points of the stator slots, wherein two of the first stator sub-packages are rotated in one circumferential direction and the remaining first stator sub-package is rotated in the opposite direction by a rotation angle about the stator axis, wherein the first stator sub-packages of the set of first stator sub-packages are distributed directly adjacent to one another in the stator package to form a group or at a distance from one another in the stator package.In addition, at least one second stator subpackage is provided in the stator core, which is arranged between first stator subpackages of a set of first stator subpackages and / or between two groups of first stator subpackages and is oriented in the circumferential direction such that the conductors of the stator winding located in the stator slots each extend at a distance from the tooth flanks of the stator slot, thereby forming slot gap channels in the stator slots. The formation of the slot gap channels allows a cooling medium, in particular oil, to flow through the stator slots along a cooling path.

[0016] It is also advantageous if the tooth tips of the first stator sub-packets are designed differently from the tooth tips of the second stator sub-packets such that, after the first stator sub-packets have been rotated, the tooth tip flanks of the first stator sub-packets are aligned with the tooth tip flanks of the second stator sub-packets. In this way, the rotation of the first stator sub-packets does not result in any steps on the tooth tip flanks, allowing the slot slots to be sealed using a sealing cord.

[0017] Furthermore, it is advantageous if at least one supply path is formed in the stator core, which is intended to supply the cooling medium to the cooling paths and opens into the stator slots via a slot inlet. Two cooling paths extending in opposite directions are provided in the respective stator slot, starting from the respective slot inlet and exiting as a free jet at the ends of the respective stator slot via a slot outlet. In this way, the cooling medium can be guided through the stator slots at low pressure, so that the respective sealing cord is subjected to only a minimal hydraulic load. Drawing

[0018] Embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description

[0019] They show:

[0020] Fig.1 is a partial view of a stator according to the invention according to a first embodiment,

[0021] Fig.2 a detailed view of the stator according to Fig.1,

[0022] Fig.3 is a partial view of a stator according to the invention according to a second embodiment,

[0023] Fig.4A a first lamella for forming a first stator sub-packet, which is intended for rotation in one of the two circumferential directions,

[0024] Fig.4B a second lamination for forming a first stator sub-packet, which is intended for rotation in an opposite circumferential direction,

[0025] Fig.4C a third lamination for forming a second stator subpackage,

[0026] Fig.5 shows in section one of the stator slots of the stator according to the invention with a conductor bundle mounted at several clamping points and

[0027] Fig.6 is a sectional view through a stator slot of the stator according to the invention.

[0028] Description of the embodiments

[0029] Fig.1 shows a partial view of a stator according to the invention according to a first embodiment.

[0030] The stator 1 of an electrical machine 2 according to the invention has a stator package 3 comprising laminations 4, on which stator teeth 5 and stator slots 6 located between the stator teeth 5 are provided and which extends around a stator axis 7.

[0031] Furthermore, the stator 1 has a stator winding 8 running in the stator slots 6. Several conductors 17 of the stator winding 8 are provided as conductor bundles for each stator slot 6. The stator teeth 5 are connected to one another via an annular stator yoke 9 and each have a tooth end 10 facing away from the stator yoke 9, which is designed as a tooth tip. The stator slots 6 have slot slots 12 formed between the respective tooth tips 10. The slot slots 12 of the stator core 3 are closed by at least one slot closure 13. This allows a cooling medium, in particular oil, to flow through the stator slots 6 along a cooling path 14.

[0032] The stator core 3 contains at least one set of three oppositely rotated first stator sub-packages 3.1 for clamping the stator winding 8 at clamping points 18 of the stator slots 6. In Fig. 1, the first stator sub-packages 3.1 are shown in the state prior to rotation for illustrative purposes. Two of the first stator sub-packages 3.1 of a set are rotated in one circumferential direction, and the remaining first stator sub-package 3.1 of the set is rotated in the opposite circumferential direction by a rotation angle t|) about the stator axis 7, as shown in Fig. 5. The first stator sub-packages 3.1 of the set of first stator sub-packages 3.1 can be distributed in groups directly adjacent to one another in the stator core 3, or individually at a distance from one another in the stator core 3.

[0033] At least one second stator sub-package 3.2 can be provided in the stator package 3, which is arranged between first stator sub-packages 3.1 of a set of first stator sub-packages 3.1 and / or between two groups of first stator sub-packages 3.1 and is aligned in the circumferential direction such that the conductors of the stator winding 8 lying in the stator slots 6 each run at a distance from the tooth flanks 5f of the stator slot 6, whereby slot gap channels 20 are formed in the stator slots 6 (Fig.5).

[0034] Fig.2 shows a detailed view of the stator according to Fig.1 .

[0035] According to the invention, the respective slot closure 13 is a sealing cord which is inserted into at least one of the slot slots 12 and is held there by a tension between two tooth tip flanks 15 of two stator teeth 5.

[0036] The tooth tip flanks 15 each have a recessed flank contour 16, which extends in the axial direction relative to the stator axis 7 and is designed to partially accommodate the respective sealing cord 13, in particular is groove-shaped or rib-shaped. The recessed flank contour 16 of the tooth ends 10 is designed, for example, to correspond to a cross-section of the sealing cord 13. This cross-section of the sealing cord 13 is a cross-section transverse to the longitudinal extent of the sealing cord 13. To create the tension of the respective sealing cord 13, a press fit can be provided according to a first embodiment. The respective sealing cord 13 is elastically designed, in particular made of an elastomer. To avoid having to press in the respective sealing cord 13, it can be inserted into the respective groove slot 12 in a state of elastic elongation and a resulting cross-sectional reduction.

[0037] According to a second embodiment, the material of the sealing cord 13 can be an expandable material, in particular a thermally expandable material or a material expandable by means of light or pressure.

[0038] According to the first embodiment, several sealing cords 13 are provided for closing the slot slots 12 of the stator 1, for example a separate sealing cord 13 for each slot slot 12.

[0039] Fig.3 shows a partial view of a stator according to the invention according to a second embodiment.

[0040] According to the second embodiment, a sealing cord 13 is provided for closing several slot slots 12 of the stator 1. For this purpose, the sealing cord 13 is guided in a meandering pattern through several, in particular all, slot slots 12.

[0041] Fig. 4A shows a partial view of a first lamination for forming a first stator subpackage, which is designed for rotation in one of the two circumferential directions. Fig. 4B shows a partial view of a second lamination for forming a first stator subpackage, which is designed for rotation in an opposite circumferential direction. Fig. 4C shows a partial view of a third lamination for forming a second stator subpackage.

[0042] The tooth tips 10 of the first stator sub-packets 3.1 are designed differently from the tooth tips 10 of the second stator sub-packets 3.2 such that the tooth tip flanks 15 of the first stator sub-packets 3.1 are aligned with the tooth tip flanks 15 of the second stator sub-packets 3.2 after the first stator sub-packets 3.1 have been rotated. To achieve this, the tooth tips 12 of the first laminations 4.1 and the tooth tips 12 of the second laminations 4.2 are designed asymmetrically with respect to the respective tooth axis 11. The first laminations 4.1 and the second laminations 4.1 can be of the same shape or identical, but arranged laterally inverted to one another. The tooth tips 12 of the third laminations 4.3 are designed, for example, symmetrically with respect to the respective tooth axis 11.

[0043] Fig.6 shows a sectional view through a stator slot of the stator according to the invention.

[0044] At least one supply path 22 is formed in the stator core 3, which is provided for supplying the cooling medium to the cooling paths 14 and opens into the stator slots 6 via a slot inlet 21. In the respective stator slot 6, two cooling paths 14 extending in opposite directions are provided, starting from the respective slot inlet 21, which exit as a free jet at the ends of the respective stator slot 6 via a slot outlet 23.

[0045] The electric machine 2 comprises a housing 25, the stator 1 arranged in the housing 25 and a rotor 26.

Claims

Claims 1. Stator of an electrical machine (2) with a stator package (3) comprising laminations (4, 4.1, 4.2, 4.3), which has stator teeth (5) and stator slots (6) located between the stator teeth (5) and extends around a stator axis (7), and with a stator winding (8) running in the stator slots (6), wherein the stator teeth (5) are connected to one another via an annular stator yoke (9) and each have a tooth end (10) facing away from the stator yoke (9), which is designed as a tooth tip, wherein the stator slots (6) have slot slots (12) formed between the respective tooth tips (10), and wherein the slot slots (12) of the stator core (3) are closed by means of at least one slot closure (13), wherein the stator slots (6) can each be flowed through by a cooling medium, in particular oil, along a cooling path (14), characterized in that the respective slot closure (13) is a sealing cord which is inserted into at least one of the slot slots (12) and is held there by means of a tension between two tooth tip flanks (15) of two stator teeth (5).

2. Stator according to claim 1, characterized in that the tooth tip flanks (15) each have a recessed flank contour (16) which extends in the axial direction with respect to the stator axis (7) and is designed to partially receive the respective sealing cord (13), in particular in the form of a groove or a groove.

3. Stator according to one of the preceding claims, characterized in that a press fit is provided to produce the tension of the respective sealing cord (13), wherein the respective sealing cord (13) is elastically designed, in particular made of an elastomer.

4. Stator according to claim 3, characterized in that the respective sealing cord (13) is inserted into the respective groove slot (12) in a state of cross-section-reducing elastic elongation.

5. Stator according to one of claims 1 or 2, characterized in that the material of the sealing cord (13) is an expandable material, in particular a thermally expandable material or a material expandable by means of light or pressure.

6. Stator according to one of the preceding claims, characterized in that a single sealing cord (13) or several sealing cords (13) are provided for closing the slotted grooves (12) of the stator (1).

7. Stator according to claim 6, characterized in that the sealing cord (13) is guided in a meandering manner through several, in particular all, slot slots (12).

8. Stator according to one of the preceding claims, characterized in that at least one set of three oppositely rotated first stator sub-packages (3.1) is provided in the stator core (3) for clamping the stator winding (8) at clamping points (18) of the stator slots (6), wherein two of the first stator sub-packages (3.1) are rotated in one circumferential direction and the remaining first stator sub-package (3.1) is rotated in the opposite direction by a rotation angle (<|)) around the stator axis (7), wherein the first stator sub-packages (3.1) of the set of first stator sub-packages (3.1) are distributed in the stator core (3) to form a group directly adjacent to one another or at a distance from one another in the stator core (3), and that at least one second stator sub-package (3.2) is provided in the stator core (3), which is arranged between first stator sub-packages (3.1) of a set of first stator sub-packages (3.1) and / or between two groups of first stator sub-packets (3.1) and is aligned in the circumferential direction such that the conductors (17) of the stator winding (8) lying in the stator slots (6) each run at a distance from the tooth flanks (5f) of the stator slot (6), whereby slot gap channels (20) are formed in the stator slots (6).

9. Stator according to claim 8, characterized in that the tooth tips (10) of the first stator sub-packets (3.1) are designed differently with respect to the tooth tips (10) of the second stator sub-packets (3.2) in such a way that the tooth tip flanks (15) of the first stator sub-packets (3.1) are aligned with the tooth tip flanks (15) of the second stator sub-packets (3.2) after the first stator sub-packets (3.1) have been rotated.

10. Stator according to one of the preceding claims, characterized in that at least one supply path (22) is formed in the stator package (3), which is provided for supplying the cooling medium to the cooling paths (14) and opens into the stator slots (6) via a slot inlet (21), wherein in the respective stator slot (6) Starting from the respective slot inlet (21), two cooling paths (14) running in opposite directions are provided, which exit as a free jet at the ends of the respective stator slot (6) via a slot outlet (23).

11. Electrical machine with a stator according to one of the preceding Claims.

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